Clinical StudyCustomized Toric Intraocular Lens Implantation in Eyes withCataract and Corneal Astigmatism after Deep Anterior LamellarKeratoplasty A Prospective Study

Domenico Schiano Lomoriello 1 Giacomo Savini 1 Kristian Naeser2

Rossella Maria Colabelli-Gisoldi3 Valeria Bono1 and Augusto Pocobelli 3

1IRCCS Fondazione GB Bietti Rome Italy2Regions Hospital Randers Randers Denmark3Azienda Ospedaliera San Giovanni-Addolorata Rome Italy

Correspondence should be addressed to Domenico Schiano Lomoriello doschianogmailcom

Received 8 February 2018 Accepted 19 April 2018 Published 3 July 2018

Academic Editor David P Pintildeero

Copyright copy 2018 Domenico Schiano Lomoriello et al (is is an open access article distributed under the Creative CommonsAttribution License which permits unrestricted use distribution and reproduction in anymedium provided the original work isproperly cited

Purpose To investigate the effectiveness of toric intraocular lenses (IOLs) for treating corneal astigmatism in patients with cataractand previous deep anterior lamellar keratoplasty (DALK) Setting San Giovanni-Addolorata Hospital Rome Italy DesignProspective interventional case seriesMethods Patients undergoing cataract surgery after DALK for keratoconus were enrolledTotal corneal astigmatism (TCA) was assessed by a rotating Scheimpflug camera combined with Placido-disk corneal topography(Sirius CSO Firenze Italy) A customized toric IOL (FIL 611 T Soleko Rome Italy) was implanted in all eyes One yearpostoperatively refraction was measured the IOL position was recorded and vectorial and nonvectorial analyses were performedto evaluate the correction of astigmatism Results Ten eyes of 10 patients were analyzed (e mean preoperative TCA magnitudewas 492plusmn 199 diopters (D) and the mean cylinder of the IOL was 618plusmn 244 After surgery the difference between the plannedaxis of orientation of the IOL and the observed axis was le10deg in all eyes(emean surgically induced corneal astigmatism was 035D at 20deg (e mean postoperative refractive astigmatism power was 113plusmn 094 D with respect to preoperative TCA the reductionwas statistically significant (plt 00001) (e mean change in astigmatism power was 380plusmn 160D corresponding to a correctionof 77 of preoperative TCA power Nine eyes out of 10 had a postoperative refractive astigmatism powerle 2D Conclusions ToricIOLs can effectively correct corneal astigmatism in eyes with previous DALK (e predictability of cylinder correction is partiallylowered by the variability of the surgically induced changes of TCA (is trial is registered with NCT03398109

1 Introduction

Tissue transparency is the main factor affecting a successfuloutcome of corneal grafts but a good postoperative refractionis also essential to achieve patientsrsquo satisfaction [1] Highastigmatism is the most common cause of unsatisfactory visionafter keratoplasty when the transplanted cornea is transparent[1 2] Spectacles and contact lenses can be adopted for regularlow-grade astigmatism but lead to poor vision or are nottolerated in cases with high astigmatism secondary to cornealtransplantation [3] Among surgical procedures arcuate ker-atotomy reduces postkeratoplasty astigmatism but the results

of this technique are often unpredictable [3 4] Both photo-refractive keratectomy (PRK) and laser in situ keratomileusis(LASIK) are effective but not suitable for all patients whounderwent corneal transplant due to the risk of complicationsand the unreliable refractive outcomes [3 5 6] Intrastromalcorneal ring segments implantation could be also a viableoption for effective correction of post-DALK astigmatism [7]However patients previously operated by penetrating kera-toplasty (PK) presenting cataract can benefit of a phacoemul-sification with toric intraocular lens (IOL) implants witha reduction of the postkeratoplasty astigmatism [8ndash15] In thelast decade several studies showed that deep anterior lamellar

HindawiJournal of OphthalmologyVolume 2018 Article ID 1649576 6 pageshttpsdoiorg10115520181649576

keratoplasty (DALK) should be preferred to PK in patients withcorneal pathology and healthy endothelium [16ndash21] becauseDALK leads to comparable visual outcomes and lower ratesof intraoperative and postoperative complications How-ever an extensive research on the major biomedical databases(PubMed Scopus ScienceDirect Google Scholar) failed toidentify studies investigating the implantation of toric IOLsafter DALK with the only exception of a case report ina patient with subluxated cataract after DALK [22] (epreoperative corneal cylinder in these eyes is often so highthat standard manufactured toric IOL powers are insufficient(erefore the purpose of this study was to assess the efficacyof custom-made toric intraocular lens implantation in pa-tients with simultaneous post-DALK high corneal astigma-tism and cataract

2 Methods

(is study was designed as a prospective noncomparativeinterventional case series It has been approved by the in-stitute review board and the regional ethical committee toadhere to the principles of the Declaration of Helsinki Allenrolled patients attended the corneal service of SanGiovanni-Addolorata Hospital where they had undergoneDALK for keratoconus between January 2007 and December2014 (ey reported a recent visual decrease in the trans-planted eye due to cataract significantly affecting the visualacuity Corneal suture removal had been performed in allcases at least 1 year before cataract surgery Corneal astig-matism was stable at least since 6 months before the cataractsurgery in all patients

21 Preoperative Examinations and Toric IOL PowerCalculation All patients underwent a comprehensive pre-operative assessment that included uncorrected distance vi-sual acuity (UDVA) distance-corrected visual acuity(DCVA) slit-lamp examination optical biometry bymeans ofpartial coherence interferometry (Carl Zeiss IOLMasterV541 Carl Zeiss Meditec Jena Germany) corneal to-mography by means of a rotating Scheimpflug cameracombined with a Placido-disc corneal topographer (SiriusCSO Firenze Italy) and specular microscope (Perseus CSOFirenze Italy) (e magnitude and direction of the IOLcylinder were based on total corneal astigmatism (TCA)measurement as calculated by the Sirius with ray-tracing overa 3mm diameter (e instrument software uses all the tracedrays to calculate the wavefront error that is the differencebetween the measured wavefront and an ideal sphericalwavefront (e wavefront error including astigmatismmagnitude and axis is then fitted using Zernike polynomialsas previously described [23] TCA values were provided to theIOL manufacturer (Soleko SpA Rome Italy) that calculatedthe required IOL cylinder by means of proprietary software(e toric IOL was customized and manufactured in 025Dcylinder steps (e implanted toric IOL was a FIL 611 T(Soleko SpA Rome Italy) whose material is afoldable ac-rylate with 25 water content (e IOL has a plate-hapticdesign a 6mm optic diameter and 1180mm overall length

(e cylindrical correction is directly built on the posteriorIOL surface (ldquoreal axis technologyrdquo) so that once implantedin the capsular bag the reference marks on the toric IOL haveto be aligned to the 0ndash180deg axis

22 Surgical Procedure Both DALK and cataract surgerywere carried out by the same experienced surgeon (AP)DALK was performed with ldquobig-bubblerdquo technique withachievement of a big bubble in all cases [16 17 24 25] Allpatients received a routine phacoemulsification surgery undertopical anesthesia Limbal marks were made at 180 degreebefore the surgery with the patients in a sitting position fo-cusing at distance Phacoemulsification was performed withthe Infiniti OZil (Alcon ForthWorth TX) through a 275mmtemporal clear cornea incision (CCI) All CCIs were per-formed as limbal as possible avoiding the corneal graft-host junction No sutures were applied at the end of thesurgeries

23 Postoperative Evaluations At 12 months post-operatively patients underwent UDVA and DCVA mea-surements slit-lamp examination under mydriasis (in orderto record the orientation of the IOL) corneal tomographyand specular microscopy (e difference between the pre-operative and postoperative TCA was used to calculate thesurgically induced corneal astigmatism (SICA)

24 Vector Analysis of Astigmatism Vector analysisaccording to Naeser [26] was used to calculate the surgicallyinduced corneal astigmatism (SICA) the difference in TCAbetween preoperative and postoperative measurements andthe error in refractive astigmatism (ERA) defined as thedifference between the observed and the targeted post-operative refractive astigmatism Briefly the net astigmatism(M at α) where M is the astigmatic magnitude in diopters(D) and α is the astigmatic direction in degrees wastransformed into two polar values in units of diopters

Meridional power polar value along the reference meridian

Φ degrees KP (Φ) M cos(2lowast(αminusΦ)) (1)

Torsional power polar value along the meridian

(Φ + 45) degrees KP (Φ + 45) M sin(2lowast(αminusΦ))

(2)

For calculation of SICA the reference plane is thesurgical meridian in zero degrees reducing (1) and (2) to

Meridional power polar value along zero degrees

KP (0) M cos(2lowast α) (3)

Torsional power polar value along the meridian 45deg

2 Journal of Ophthalmology

KP (45) M sin(2lowast α) (4)

KP(0) is negative for a flattening and positive fora steepening of the surgical meridian along zero degrees

KP(45) is negative for a clockwise and positive fora counterclockwise rotation of the cylinder median in re-lation to the horizontal meridian Refractive data weretransformed from the vertex to the corneal plane and thenfurther to polar values Meridional and torsional powerswere reconverted to the usual net cylinder notation bymeansof the following general equations [26]

M

KP(Φ)2 + KP(Φ + 45)21113969

α arc tanMminusKP(Φ)

KP(Φ + 45)1113888 1113889 +Φ

(5)

Equation (5) was used also to calculate the ERAaccording to two models as previously reported [27]

(i) Model 1 is based on preoperative corneal mea-surements mean observed SICA observed IOL axisposition and IOL toric power at the corneal plane(as calculated by the manufacturer) In this modelthe reference meridian Φ is the target TCA definedas the vector sum of the preoperative TCA and theSICA

(ii) Model 2 is based on postoperative corneal mea-surements observed IOL axis position and IOL toricpower at the corneal plane (as calculated by themanufacturer) In this model the reference meridianΦ is the postoperative TCA

(e interpretation of ERA was identical for both modelsKP(Φ) is negative for an overcorrection and positive for anundercorrection along the reference meridian KP(Φ+ 45) isnegative for a clockwise and positive for a counterclockwiserotation of the cylinder median in relation to the referencemeridian

25 Statistical Analysis All statistical tests were performedusing Instat (version 310 for Windows GraphPad SoftwareLa Jolla CA) (eWilcoxon matched pairs signed-ranks testwas used to compare the mean values (e Wilcoxon ranksum test was used to investigate the difference of one samplewith respect to zero A p valuelt 005 was considered sta-tistically significant

3 Results

Ten eyes of 10 patients (6 men) were enrolled Mean age was671plusmn 73 years (range 56 to 76 years) Cataract surgery andtoric IOL implantation were carried out in all cases with nocomplications (e mean IOL power was 109plusmn 79D (rangeminus125 to +215) and the mean cylinder at the IOL plane was618plusmn 244D (range +325 to +115) (e mean follow-upafter cataract surgery was 159plusmn 89 months (range 7 to 30months) Postoperatively at the end of follow-up the 0ndash180degreference marks on the IOL were oriented on average at1756deg (range 170ndash5deg) and in 100 of eyes the differencebetween the planned axis of orientation and the observedaxis was le10deg (e preoperative and postoperative param-eters and the spherical equivalent power and cylinder powerof the implanted IOL are reported in Table 1 Post-operatively both UDVA and DCVA improved significantlywith respect to the corresponding preoperative valuesUDVA improved from 153plusmn 054 to 029plusmn 013 LogMAR(p 00039) and DCVA improved from 055plusmn 029 to014plusmn 012 LogMAR (p 0002) (e postoperative re-fraction spherical equivalent was minus016plusmn 084D

31 Surgically Induced Corneal Astigmatism (SICA)Surgery produced an average 027plusmn 116D steepening alongthe incision meridian and an average 023plusmn 144D coun-terclockwise rotation over the horizontal surgical meridian(Table 2) (ese values correspond to a mean SICA of 035D at 20deg No statistically significant differences were foundbetween the average preoperative and postoperative valuesof meridional and torsional power Surgery had little effecton the orientation of the steepest TCA axis since a change inaxis orientation of the steepest meridian gt10deg was observedjust in 1 eye

32 Error in Refractive Astigmatism (e absolute meanpostoperative refractive astigmatism power (at the cornealplane) was 113plusmn 094D (range 0ndash3D) Compared to thepreoperative TCA power 492 plusmn 199 D the resulting av-erage 380 plusmn 160 D reduction was statistically significant(plt 0002) and allowed us to correct 77plusmn 16 of the pre-operative TCA magnitude (range 489 to 100 ) Nine eyesout of 10 had a postoperative refractive astigmatism powerle2D whereas preoperatively TCA was ge2D in all eyesCalculations of ERA meridional powers revealed small

Table 1 Pre- and postoperative operative clinical data of patients

Sim K TCP TCA power (D) Axial length (mm) DCVA (LogMAR) UDVA (LogMAR)

Preoperative4537 (plusmn219) 4450 (plusmn233) 492 (plusmn199) 2684 (plusmn216) 055 (plusmn029) 153 (plusmn054)

4509 4152 447 2709 045 1654271ndash4929 4399ndash4789 266ndash932 226ndash297 10ndash02 20ndash07

Postoperative4554 (plusmn219) 4443 (plusmn222) 508 (plusmn276)

NA014 (plusmn012) 029 (plusmn013)

lowast4316 lowast4122 lowast421 lowastlowast015 dagger034494ndash4931 4419ndash4783 352ndash1255 03ndash0 05ndash0

Sim K simulated keratometry TCP total corneal power measured by ray-tracing TCA total corneal astigmatism DCVA distance-corrected visualacuity UDVA uncorrected distance visual acuity IOL intraocular lens Each entity is reported as average (plusmnSD) median minimal valuendashmaximal valuelowastNot statistically significant lowastlowastp 00020 daggerp 00039

Journal of Ophthalmology 3

average overcorrections of 003 (plusmn113) D and 036 (plusmn104) Dfor measurements based on preoperative and postoperativeTCA respectively Torsional powers disclosed averagecounterclockwise rotations amounting to 055plusmn 122D and034plusmn 179 D None of these meridional and torsional av-erage powers differed significantly from zero Figures 1 and 2show the distribution of individual and mean ERA based onboth preoperative and postoperative TCA measurementsERA mean absolute error (MAE) amounted to 143plusmn 091Dand 169plusmn 118D for preoperative and postoperative TCAmeasurements with no statistically significant differencebetween them (e postoperative endothelial cell reductionwas 8 compared to preoperative values No patients hadpostoperative corneal decompensation

4 Discussion

Our results show that cataract extraction with toric IOLimplantation is effective to reduce astigmatism and improvevisual acuity in patients with previous DALK Postoperative

improvements of UDVA CDVA and astigmatism were allstatistically significant Previous studies reported the effec-tiveness of toric IOL s implantation in eyes with previous PK[8ndash15] A retrospective study recently published on a peer-reviewed but not indexed journal describes good outcomesfor toric IOLs in eyes with previous DALK [28] Our dataconfirm these results as shown by the significant im-provement of UDVA and CDVA and add some interestingfindings related to vector analysis (which was not carried outby Scorcia et al) [28] In our sample the refractive pre-dictability was good as in 90 of patients the postoperativerefractive astigmatism was within 2 D and on average morethan 75 of astigmatismmagnitude was corrected(e goodoutcomes can be related to two factors at least First the toricIOLwas customized that is manufactured in steps of 025Daccording to the axial length and corneal astigmatism valuesthat we supplied preoperatively Moreover the cylinderpower of the IOL could be manufactured to correct as manyas more than 9 D which is not possible with standard toricIOLs Second calculations were based on TCA rather thanon KA as the former has been shown to provide more

Table 2 Meridional and torsional power of preoperative and postoperative total corneal astigmatism and the surgically induced cornealastigmatism (SICA)

Meridional power Torsional powerPreoperative minus011plusmn 360 052 minus487 to 438 minus193plusmn 372 minus271 minus670 to 348Postoperative 016plusmn 410 minus032 minus572 to 738 minus170plusmn 403 minus238 minus1015 to 316p value 06953 06953SICA 027plusmn 116 028 minus086 to +300 023plusmn 144 012 minus200 to +242SICA is defined as the difference between preoperative and postoperative total corneal astigmatism Each entity is reported as average (plusmnSD) median minimalvaluendashmaximal value All units are in diopters (D)

0000

ndash10

ndash20

ndash30

ndash40

10

20

30

ndash10ndash20ndash30ndash40 10

Meridional polar value in diopters

Tors

iona

l pol

ar v

alue

s in

diop

ters

ERA from preoperative TCA

20 30

Figure 1 (e error in refractive astigmatism (ERA) in calculationsbased on preoperatively measured total corneal astigmatism(TCA)X-axis ERA expressed as themeridional polar value Y-axisERA expressed as the torsional polar value (e small colored dotsindicate the individual observations (e large black dots indicatethe combined mean (centroid)

Meridional polar values in diopters

Tors

iona

l pol

ar v

alue

s in

diop

ters

ERA from postoperative TCA

00

ndash10

ndash20

ndash30

ndash40

10

20

30

ndash10ndash20ndash30ndash40 10 20 3000

Figure 2 (e error in refractive astigmatism (ERA) in calculationsbased on postoperatively measured total corneal astigmatism(TCA)X-axis ERA expressed as themeridional polar value Y-axisERA expressed as the torsional polar value (e small colored dotsindicate the individual observations (e large black dots indicatethe combined mean (centroid)

4 Journal of Ophthalmology

accurate results [29] Vector analysis showed that using bothpreoperative and postoperative TCA leads to a good pre-dictability in the refractive outcome as the average ERA wasclose to zero in both cases (e ERA standard deviations formeridional (plusmn113D) and torsional (plusmnD) powers should becompared to the approximateplusmn 060D values for normaleyes [29] (e relatively large variability may depend ona lower repeatability of TCA measurements in eyes withirregular astigmatism On the other hand the predictabilityof astigmatism correction in these eyes can be reduced due toany irregular component of corneal astigmatism whichcannot be corrected by toric IOLs and by the variable SICAinduced by the incision In this regard although vectoranalysis revealed a minimal average SICA (just 035D at 20deg)we should consider that this value is misleading as oppositeastigmatism is cancelled out by vector analysis A morerealistic value is provided by the range of the meridional(from minus086 to +300D) and torsional (from minus200 to+242D) power changes in corneal astigmatism whichhighlight the risk of TCA changes induced by the incision(e SICA standard deviations for meridional and torsionalpower in normal eyes were recently reported asplusmn 040Dandplusmn 048D [29] which is far less than the similar valuesofplusmn 116D andplusmn 144D in the present series Usually sur-gery induces a corneal flattening along the surgical meridianand a compensatory steepening along its orthogonal me-ridian the so-called coupling effect [26] In the presentstudy a 027D steepening was observed (is average resultwas influenced by a 30D corneal steepening in a single eyewith a preoperative TCA of 932D However corneal bio-mechanics are obviously changed after DALK surgerywhich may explain the absence of the normal averageflattening We also found a good rotational stability of thetoric IOL since in no case the misalignment of the main axisof the IOL with respect to the 0ndash180deg axis was higher than 10degat the last follow-up (ese results are in good agreementwith previous studies on toric IOLs only in eyes with PK[11 12] As a secondary outcome we observed that allsurgeries were safe and well tolerated by the corneal en-dothelium During the follow-up period there were nopostoperative complications of the grafts No episodes ofimmune-mediated rejection or other complications poten-tially compromising the VA were recorded [30]

Readers may be concerned about the mean age of oursample (671plusmn 73 years) as this means that our patients didnot undergo DALK in their 20s or 30s as it usually happensbut in their 50s or 60s (e surgical indication at this age wasmainly due to contact lens intolerance or progressive visualimpairment

(is study has some limitations that warrant furtherinvestigations First the sample size was small Second wecompared the preoperative TCA to the postoperative re-fractive astigmatism in order to evaluate the reduction of theastigmatism magnitude (is is not an ideal method becauseit compares values obtained from different measurements(Scheimpflug imaging of the cornea versus refraction)However due to the presence of cataract the measurementof the preoperative refractive astigmatism would not bereliable so that total corneal astigmatism seems to be the

best parameter for comparisons In conclusion our resultssuggest that toric IOL implantation after cataract surgery inpatients previously treated with DALK represents a safe andeffective procedure for the correction of astigmatism

Data Availability

All relevant data are available from the ldquoFondazione GBBiettirdquo for researchers who meet the criteria for access toconfidential data

Conflicts of Interest

(e authors declare that there are no conflicts of interestregarding the publication of this paper

Acknowledgments

(is study was supported by the Italian Ministry of Healthand Fondazione Roma

References

[1] A Vail S M Gore B A Bradley D L Easty C A Rogersand W J Armitage ldquoConclusions of the corneal transplantfollow up studyrdquo British Journal of Ophthalmology vol 81no 8 pp 631ndash636 1997

[2] P S Binder ldquo(e effect of suture removal on postkeratoplastyastigmatismrdquo American Journal of Ophthalmology vol 105no 6 pp 637ndash645 1988

[3] S Feizi and M Zare ldquoCurrent approaches for management ofpostpenetrating keratoplasty astigmatismrdquo Journal of Oph-thalmology vol 2011 Article ID 708736 8 pages 2011

[4] M R Mandel M B Shapiro and J H Krachmer ldquoRelaxingincisions with augmentation sutures for the correction ofpostkeratoplasty astigmatismrdquo American Journal of Oph-thalmology vol 103 no 3 pp 441ndash447 1987

[5] K Bilgihan S C Ozdek F Akata and B HasanreisogluldquoPhotorefractive keratectomy for post-penetrating kerato-plasty myopia and astigmatismrdquo Journal of Cataract amp Re-fractive Surgery vol 26 no 11 pp 1590ndash1595 2000

[6] K Buzard J-L Febbraro and B R Fundingsland ldquoLaser insitu keratomileusis for the correction of residual ametropiaafter penetrating keratoplastyrdquo Journal of Cataract ampRe-fractive Surgery vol 30 no 5 pp 1006ndash1013 2004

[7] J C D Arantes S Coscarelli P Ferrara L P N AraujoM Avila and L Torquetti ldquoIntrastromal corneal ring seg-ments for astigmatism correction after deep anterior lamellarkeratoplastyrdquo Journal of Ophthalmology vol 2017 Article ID8689017 7 pages 2017

[8] M Wade R F Steinert S Garg M Farid and R GasterldquoResults of toric intraocular lenses for post-penetrating ker-atoplasty astigmatismrdquo Ophthalmology vol 121 no 3pp 771ndash777 2014

[9] N Visser R Ruız-Mesa F Pastor N J C BauerR M M A Nuijts and R Montes-Mico ldquoCataract surgerywith toric intraocular lens implantation in patients with highcorneal astigmatismrdquo Journal of Cataract and RefractiveSurgery vol 37 no 8 pp 1403ndash1410 2011

[10] S Srinivasan D S J Ting and D A M Lyall ldquoImplantation ofa customized toric intraocular lens for correction of post-keratoplasty astigmatismrdquoEye vol 27 no 4 article 531537 2013

Journal of Ophthalmology 5

[11] CM Stewart and J C McAlister ldquoComparison of grafted andnon-grafted patients with corneal astigmatism undergoingcataract extraction with a toric intraocular lens implantrdquoClinical ampExperimental Ophthalmology vol 38 no 8pp 747ndash757 2010

[12] U De Sanctis C Eandi and F Grignolo ldquoPhacoemulsifi-cation and customized toric intraocular lens implantation ineyes with cataract and high astigmatism after penetratingkeratoplastyrdquo Journal of Cataract and Refractive Surgeryvol 37 no 4 pp 781ndash785 2011

[13] D Lockington E Wang D V Patel S P Moore andC N J McGhee ldquoEffectiveness of cataract phacoemulsifi-cation with toric intraocular lenses in addressing astigmatismafter keratoplastyrdquo Journal of Cataract Refractive Surgeryvol 40 no 12 pp 2044ndash2049 2014

[14] I Klftuoglu Y A Akova S Egrilmez and S G Yilmaz ldquo(eresults of toric intraocular lens implantation in patients withcataract and high astigmatism after penetrating keratoplastyrdquoC vol 42 no 2 pp e8ndashe11 2016

[15] L Kessel J Andresen B Tendal D Erngaard P Flesner andJ Hjortdal ldquoToricintraocular lenses in the correction ofastigmatism during cataract surgery a systematic review andmeta-analysisrdquo Ophthalmology vol 123 no 2 pp 275ndash2862016

[16] M Anwar ldquoIndication to deep anterior lamellar keratoplastyrdquoin Cornea Surgery of the Cornea and Conjunctiva ElsevierInc New York NY USA 2013

[17] M Anwar and K D Teichmann ldquoBig-bubble technique tobare descemetrsquos membrane in anterior lamellar keratoplastyrdquoJournal of Cataract ampRefractive Surgery vol 28 no 3pp 398ndash403 2002

[18] V M Borderie A Werthel O Touzeau C AllouchS Boutboul and L Laroche ldquoComparison of techniques usedfor removing the recipient stroma in anterior lamellar ker-atoplastyrdquo Archives of Ophthalmology vol 126 no 1pp 31ndash37 2008

[19] S L Watson A Ramsay J K G Dart C Bunce and E CraigldquoComparison of deep lamellar keratoplasty and penetratingkeratoplasty in patients with keratoconusrdquo Ophthalmologyvol 111 no 9 pp 1676ndash1682 2004

[20] R Macintyre S-P Chow E Chan and A Poon ldquoLong-termoutcomes of deep anterior lamellar keratoplasty versuspenetrating keratoplasty in Australian keratoconus patientsrdquoCornea vol 33 no 1 pp 6ndash9 2014

[21] J H Krumeich A Knlle and B M Krumeich ldquodeep anteriorlamellar (dalk) vs penetrating keratoplasty (pkp) a clinicaland statistical analysisrdquo Klinische Monatsblatter fur Augen-heilkunde vol 225 no 7 pp 637ndash648 2008

[22] A Kandar ldquoCombined special capsular tension ring andtoriciol implantation for management of post-dalk highregular astigmatism with subluxated traumatic cataractrdquoIndian Journal of Ophthalmology vol 62 no 7 pp 819ndash8222014

[23] G Savini F Versaci G Vestri P Ducoli and K Nr ldquoIn-fluence of posterior corneal astigmatism on total cornealastigmatism in eyes with moderate to high astigmatismrdquoJournal of Cataract and Refractive Surgery vol 40 no 10pp 1645ndash1653 2014

[24] N Ardjomand S Hau J C McAlister et al ldquoQuality of visionand graft thickness in deep anterior lamellar and penetratingcorneal allograftsrdquo American Journal of Ophthalmologyvol 143 no 2 pp 228ndash235 2007

[25] D Schiano-Lomoriello R Annamaria Colabelli-GisoldiM Nubile et al ldquoDescemetic and predescemetic dalk in

keratoconus patients a clinical and confocal perspectivestudyrdquo BioMed Research International vol 2014 Article ID123156 7 pages 2014

[26] K Naeser ldquoAssessment and statistics of surgically inducedastigmatismrdquo Actaophthalmologica vol 86 no 3 p 3492008

[27] G Savini K Naeser D Schiano-Lomoriello and P DucolildquoOptimized keratometry and total corneal astigmatism fortoric intraocular lens calculationrdquo Journal of Cataract ampRefractive Surgery vol 43 no 9 pp 1140ndash1148 2017

[28] V Scorcia A Lucisano V Savoca Corona V De LucaA Carnevali and M Busin ldquoDeep anterior lamellar kera-toplasty followed by toric lens implantation for the treatmentof concomitant anterior stromal diseases and cataractrdquoOphthalmology at Point of Care vol 1 no 1 articleoapoc0000008 2017

[29] G Savini and K Naeser ldquoAn analysis of the factors influ-encing the residual refractive astigmatism after cataractsurgery with toric intraocular lensesrdquo Investigative Oph-thalmology Visual Science vol 56 no 2 pp 827ndash835 2015

[30] B Acar C Utine S Acar and F Ciftci ldquoEndothelial cell lossafter phacoemulsification in eyes with previous penetratingkeratoplasty previous deep anterior lamellar keratoplasty orno previous surgeryrdquo Journal of Cataract and RefractiveSurgery vol 37 no 11 pp 2013ndash2017 2011

6 Journal of Ophthalmology

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Submit your manuscripts atwwwhindawicom

KP (45) M sin(2lowast α) (4)

KP(0) is negative for a flattening and positive fora steepening of the surgical meridian along zero degrees

KP(45) is negative for a clockwise and positive fora counterclockwise rotation of the cylinder median in re-lation to the horizontal meridian Refractive data weretransformed from the vertex to the corneal plane and thenfurther to polar values Meridional and torsional powerswere reconverted to the usual net cylinder notation bymeansof the following general equations [26]

M

KP(Φ)2 + KP(Φ + 45)21113969

α arc tanMminusKP(Φ)

KP(Φ + 45)1113888 1113889 +Φ

(5)

Equation (5) was used also to calculate the ERAaccording to two models as previously reported [27]

(i) Model 1 is based on preoperative corneal mea-surements mean observed SICA observed IOL axisposition and IOL toric power at the corneal plane(as calculated by the manufacturer) In this modelthe reference meridian Φ is the target TCA definedas the vector sum of the preoperative TCA and theSICA

(ii) Model 2 is based on postoperative corneal mea-surements observed IOL axis position and IOL toricpower at the corneal plane (as calculated by themanufacturer) In this model the reference meridianΦ is the postoperative TCA

(e interpretation of ERA was identical for both modelsKP(Φ) is negative for an overcorrection and positive for anundercorrection along the reference meridian KP(Φ+ 45) isnegative for a clockwise and positive for a counterclockwiserotation of the cylinder median in relation to the referencemeridian

25 Statistical Analysis All statistical tests were performedusing Instat (version 310 for Windows GraphPad SoftwareLa Jolla CA) (eWilcoxon matched pairs signed-ranks testwas used to compare the mean values (e Wilcoxon ranksum test was used to investigate the difference of one samplewith respect to zero A p valuelt 005 was considered sta-tistically significant

3 Results

Ten eyes of 10 patients (6 men) were enrolled Mean age was671plusmn 73 years (range 56 to 76 years) Cataract surgery andtoric IOL implantation were carried out in all cases with nocomplications (e mean IOL power was 109plusmn 79D (rangeminus125 to +215) and the mean cylinder at the IOL plane was618plusmn 244D (range +325 to +115) (e mean follow-upafter cataract surgery was 159plusmn 89 months (range 7 to 30months) Postoperatively at the end of follow-up the 0ndash180degreference marks on the IOL were oriented on average at1756deg (range 170ndash5deg) and in 100 of eyes the differencebetween the planned axis of orientation and the observedaxis was le10deg (e preoperative and postoperative param-eters and the spherical equivalent power and cylinder powerof the implanted IOL are reported in Table 1 Post-operatively both UDVA and DCVA improved significantlywith respect to the corresponding preoperative valuesUDVA improved from 153plusmn 054 to 029plusmn 013 LogMAR(p 00039) and DCVA improved from 055plusmn 029 to014plusmn 012 LogMAR (p 0002) (e postoperative re-fraction spherical equivalent was minus016plusmn 084D

31 Surgically Induced Corneal Astigmatism (SICA)Surgery produced an average 027plusmn 116D steepening alongthe incision meridian and an average 023plusmn 144D coun-terclockwise rotation over the horizontal surgical meridian(Table 2) (ese values correspond to a mean SICA of 035D at 20deg No statistically significant differences were foundbetween the average preoperative and postoperative valuesof meridional and torsional power Surgery had little effecton the orientation of the steepest TCA axis since a change inaxis orientation of the steepest meridian gt10deg was observedjust in 1 eye

32 Error in Refractive Astigmatism (e absolute meanpostoperative refractive astigmatism power (at the cornealplane) was 113plusmn 094D (range 0ndash3D) Compared to thepreoperative TCA power 492 plusmn 199 D the resulting av-erage 380 plusmn 160 D reduction was statistically significant(plt 0002) and allowed us to correct 77plusmn 16 of the pre-operative TCA magnitude (range 489 to 100 ) Nine eyesout of 10 had a postoperative refractive astigmatism powerle2D whereas preoperatively TCA was ge2D in all eyesCalculations of ERA meridional powers revealed small

Table 1 Pre- and postoperative operative clinical data of patients

Sim K TCP TCA power (D) Axial length (mm) DCVA (LogMAR) UDVA (LogMAR)

Preoperative4537 (plusmn219) 4450 (plusmn233) 492 (plusmn199) 2684 (plusmn216) 055 (plusmn029) 153 (plusmn054)

4509 4152 447 2709 045 1654271ndash4929 4399ndash4789 266ndash932 226ndash297 10ndash02 20ndash07

Postoperative4554 (plusmn219) 4443 (plusmn222) 508 (plusmn276)

NA014 (plusmn012) 029 (plusmn013)

lowast4316 lowast4122 lowast421 lowastlowast015 dagger034494ndash4931 4419ndash4783 352ndash1255 03ndash0 05ndash0

Sim K simulated keratometry TCP total corneal power measured by ray-tracing TCA total corneal astigmatism DCVA distance-corrected visualacuity UDVA uncorrected distance visual acuity IOL intraocular lens Each entity is reported as average (plusmnSD) median minimal valuendashmaximal valuelowastNot statistically significant lowastlowastp 00020 daggerp 00039

Journal of Ophthalmology 3

average overcorrections of 003 (plusmn113) D and 036 (plusmn104) Dfor measurements based on preoperative and postoperativeTCA respectively Torsional powers disclosed averagecounterclockwise rotations amounting to 055plusmn 122D and034plusmn 179 D None of these meridional and torsional av-erage powers differed significantly from zero Figures 1 and 2show the distribution of individual and mean ERA based onboth preoperative and postoperative TCA measurementsERA mean absolute error (MAE) amounted to 143plusmn 091Dand 169plusmn 118D for preoperative and postoperative TCAmeasurements with no statistically significant differencebetween them (e postoperative endothelial cell reductionwas 8 compared to preoperative values No patients hadpostoperative corneal decompensation

4 Discussion

Our results show that cataract extraction with toric IOLimplantation is effective to reduce astigmatism and improvevisual acuity in patients with previous DALK Postoperative

improvements of UDVA CDVA and astigmatism were allstatistically significant Previous studies reported the effec-tiveness of toric IOL s implantation in eyes with previous PK[8ndash15] A retrospective study recently published on a peer-reviewed but not indexed journal describes good outcomesfor toric IOLs in eyes with previous DALK [28] Our dataconfirm these results as shown by the significant im-provement of UDVA and CDVA and add some interestingfindings related to vector analysis (which was not carried outby Scorcia et al) [28] In our sample the refractive pre-dictability was good as in 90 of patients the postoperativerefractive astigmatism was within 2 D and on average morethan 75 of astigmatismmagnitude was corrected(e goodoutcomes can be related to two factors at least First the toricIOLwas customized that is manufactured in steps of 025Daccording to the axial length and corneal astigmatism valuesthat we supplied preoperatively Moreover the cylinderpower of the IOL could be manufactured to correct as manyas more than 9 D which is not possible with standard toricIOLs Second calculations were based on TCA rather thanon KA as the former has been shown to provide more

Table 2 Meridional and torsional power of preoperative and postoperative total corneal astigmatism and the surgically induced cornealastigmatism (SICA)

Meridional power Torsional powerPreoperative minus011plusmn 360 052 minus487 to 438 minus193plusmn 372 minus271 minus670 to 348Postoperative 016plusmn 410 minus032 minus572 to 738 minus170plusmn 403 minus238 minus1015 to 316p value 06953 06953SICA 027plusmn 116 028 minus086 to +300 023plusmn 144 012 minus200 to +242SICA is defined as the difference between preoperative and postoperative total corneal astigmatism Each entity is reported as average (plusmnSD) median minimalvaluendashmaximal value All units are in diopters (D)

0000

ndash10

ndash20

ndash30

ndash40

10

20

30

ndash10ndash20ndash30ndash40 10

Meridional polar value in diopters

Tors

iona

l pol

ar v

alue

s in

diop

ters

ERA from preoperative TCA

20 30

Figure 1 (e error in refractive astigmatism (ERA) in calculationsbased on preoperatively measured total corneal astigmatism(TCA)X-axis ERA expressed as themeridional polar value Y-axisERA expressed as the torsional polar value (e small colored dotsindicate the individual observations (e large black dots indicatethe combined mean (centroid)

Meridional polar values in diopters

Tors

iona

l pol

ar v

alue

s in

diop

ters

ERA from postoperative TCA

00

ndash10

ndash20

ndash30

ndash40

10

20

30

ndash10ndash20ndash30ndash40 10 20 3000

Figure 2 (e error in refractive astigmatism (ERA) in calculationsbased on postoperatively measured total corneal astigmatism(TCA)X-axis ERA expressed as themeridional polar value Y-axisERA expressed as the torsional polar value (e small colored dotsindicate the individual observations (e large black dots indicatethe combined mean (centroid)

4 Journal of Ophthalmology

accurate results [29] Vector analysis showed that using bothpreoperative and postoperative TCA leads to a good pre-dictability in the refractive outcome as the average ERA wasclose to zero in both cases (e ERA standard deviations formeridional (plusmn113D) and torsional (plusmnD) powers should becompared to the approximateplusmn 060D values for normaleyes [29] (e relatively large variability may depend ona lower repeatability of TCA measurements in eyes withirregular astigmatism On the other hand the predictabilityof astigmatism correction in these eyes can be reduced due toany irregular component of corneal astigmatism whichcannot be corrected by toric IOLs and by the variable SICAinduced by the incision In this regard although vectoranalysis revealed a minimal average SICA (just 035D at 20deg)we should consider that this value is misleading as oppositeastigmatism is cancelled out by vector analysis A morerealistic value is provided by the range of the meridional(from minus086 to +300D) and torsional (from minus200 to+242D) power changes in corneal astigmatism whichhighlight the risk of TCA changes induced by the incision(e SICA standard deviations for meridional and torsionalpower in normal eyes were recently reported asplusmn 040Dandplusmn 048D [29] which is far less than the similar valuesofplusmn 116D andplusmn 144D in the present series Usually sur-gery induces a corneal flattening along the surgical meridianand a compensatory steepening along its orthogonal me-ridian the so-called coupling effect [26] In the presentstudy a 027D steepening was observed (is average resultwas influenced by a 30D corneal steepening in a single eyewith a preoperative TCA of 932D However corneal bio-mechanics are obviously changed after DALK surgerywhich may explain the absence of the normal averageflattening We also found a good rotational stability of thetoric IOL since in no case the misalignment of the main axisof the IOL with respect to the 0ndash180deg axis was higher than 10degat the last follow-up (ese results are in good agreementwith previous studies on toric IOLs only in eyes with PK[11 12] As a secondary outcome we observed that allsurgeries were safe and well tolerated by the corneal en-dothelium During the follow-up period there were nopostoperative complications of the grafts No episodes ofimmune-mediated rejection or other complications poten-tially compromising the VA were recorded [30]

Readers may be concerned about the mean age of oursample (671plusmn 73 years) as this means that our patients didnot undergo DALK in their 20s or 30s as it usually happensbut in their 50s or 60s (e surgical indication at this age wasmainly due to contact lens intolerance or progressive visualimpairment

(is study has some limitations that warrant furtherinvestigations First the sample size was small Second wecompared the preoperative TCA to the postoperative re-fractive astigmatism in order to evaluate the reduction of theastigmatism magnitude (is is not an ideal method becauseit compares values obtained from different measurements(Scheimpflug imaging of the cornea versus refraction)However due to the presence of cataract the measurementof the preoperative refractive astigmatism would not bereliable so that total corneal astigmatism seems to be the

best parameter for comparisons In conclusion our resultssuggest that toric IOL implantation after cataract surgery inpatients previously treated with DALK represents a safe andeffective procedure for the correction of astigmatism

Data Availability

All relevant data are available from the ldquoFondazione GBBiettirdquo for researchers who meet the criteria for access toconfidential data

Conflicts of Interest

(e authors declare that there are no conflicts of interestregarding the publication of this paper

Acknowledgments

(is study was supported by the Italian Ministry of Healthand Fondazione Roma

References

[1] A Vail S M Gore B A Bradley D L Easty C A Rogersand W J Armitage ldquoConclusions of the corneal transplantfollow up studyrdquo British Journal of Ophthalmology vol 81no 8 pp 631ndash636 1997

[2] P S Binder ldquo(e effect of suture removal on postkeratoplastyastigmatismrdquo American Journal of Ophthalmology vol 105no 6 pp 637ndash645 1988

[3] S Feizi and M Zare ldquoCurrent approaches for management ofpostpenetrating keratoplasty astigmatismrdquo Journal of Oph-thalmology vol 2011 Article ID 708736 8 pages 2011

[4] M R Mandel M B Shapiro and J H Krachmer ldquoRelaxingincisions with augmentation sutures for the correction ofpostkeratoplasty astigmatismrdquo American Journal of Oph-thalmology vol 103 no 3 pp 441ndash447 1987

[5] K Bilgihan S C Ozdek F Akata and B HasanreisogluldquoPhotorefractive keratectomy for post-penetrating kerato-plasty myopia and astigmatismrdquo Journal of Cataract amp Re-fractive Surgery vol 26 no 11 pp 1590ndash1595 2000

[6] K Buzard J-L Febbraro and B R Fundingsland ldquoLaser insitu keratomileusis for the correction of residual ametropiaafter penetrating keratoplastyrdquo Journal of Cataract ampRe-fractive Surgery vol 30 no 5 pp 1006ndash1013 2004

[7] J C D Arantes S Coscarelli P Ferrara L P N AraujoM Avila and L Torquetti ldquoIntrastromal corneal ring seg-ments for astigmatism correction after deep anterior lamellarkeratoplastyrdquo Journal of Ophthalmology vol 2017 Article ID8689017 7 pages 2017

[8] M Wade R F Steinert S Garg M Farid and R GasterldquoResults of toric intraocular lenses for post-penetrating ker-atoplasty astigmatismrdquo Ophthalmology vol 121 no 3pp 771ndash777 2014

[9] N Visser R Ruız-Mesa F Pastor N J C BauerR M M A Nuijts and R Montes-Mico ldquoCataract surgerywith toric intraocular lens implantation in patients with highcorneal astigmatismrdquo Journal of Cataract and RefractiveSurgery vol 37 no 8 pp 1403ndash1410 2011

[10] S Srinivasan D S J Ting and D A M Lyall ldquoImplantation ofa customized toric intraocular lens for correction of post-keratoplasty astigmatismrdquoEye vol 27 no 4 article 531537 2013

Journal of Ophthalmology 5

[11] CM Stewart and J C McAlister ldquoComparison of grafted andnon-grafted patients with corneal astigmatism undergoingcataract extraction with a toric intraocular lens implantrdquoClinical ampExperimental Ophthalmology vol 38 no 8pp 747ndash757 2010

[12] U De Sanctis C Eandi and F Grignolo ldquoPhacoemulsifi-cation and customized toric intraocular lens implantation ineyes with cataract and high astigmatism after penetratingkeratoplastyrdquo Journal of Cataract and Refractive Surgeryvol 37 no 4 pp 781ndash785 2011

[13] D Lockington E Wang D V Patel S P Moore andC N J McGhee ldquoEffectiveness of cataract phacoemulsifi-cation with toric intraocular lenses in addressing astigmatismafter keratoplastyrdquo Journal of Cataract Refractive Surgeryvol 40 no 12 pp 2044ndash2049 2014

[14] I Klftuoglu Y A Akova S Egrilmez and S G Yilmaz ldquo(eresults of toric intraocular lens implantation in patients withcataract and high astigmatism after penetrating keratoplastyrdquoC vol 42 no 2 pp e8ndashe11 2016

[15] L Kessel J Andresen B Tendal D Erngaard P Flesner andJ Hjortdal ldquoToricintraocular lenses in the correction ofastigmatism during cataract surgery a systematic review andmeta-analysisrdquo Ophthalmology vol 123 no 2 pp 275ndash2862016

[16] M Anwar ldquoIndication to deep anterior lamellar keratoplastyrdquoin Cornea Surgery of the Cornea and Conjunctiva ElsevierInc New York NY USA 2013

[17] M Anwar and K D Teichmann ldquoBig-bubble technique tobare descemetrsquos membrane in anterior lamellar keratoplastyrdquoJournal of Cataract ampRefractive Surgery vol 28 no 3pp 398ndash403 2002

[18] V M Borderie A Werthel O Touzeau C AllouchS Boutboul and L Laroche ldquoComparison of techniques usedfor removing the recipient stroma in anterior lamellar ker-atoplastyrdquo Archives of Ophthalmology vol 126 no 1pp 31ndash37 2008

[19] S L Watson A Ramsay J K G Dart C Bunce and E CraigldquoComparison of deep lamellar keratoplasty and penetratingkeratoplasty in patients with keratoconusrdquo Ophthalmologyvol 111 no 9 pp 1676ndash1682 2004

[20] R Macintyre S-P Chow E Chan and A Poon ldquoLong-termoutcomes of deep anterior lamellar keratoplasty versuspenetrating keratoplasty in Australian keratoconus patientsrdquoCornea vol 33 no 1 pp 6ndash9 2014

[21] J H Krumeich A Knlle and B M Krumeich ldquodeep anteriorlamellar (dalk) vs penetrating keratoplasty (pkp) a clinicaland statistical analysisrdquo Klinische Monatsblatter fur Augen-heilkunde vol 225 no 7 pp 637ndash648 2008

[22] A Kandar ldquoCombined special capsular tension ring andtoriciol implantation for management of post-dalk highregular astigmatism with subluxated traumatic cataractrdquoIndian Journal of Ophthalmology vol 62 no 7 pp 819ndash8222014

[23] G Savini F Versaci G Vestri P Ducoli and K Nr ldquoIn-fluence of posterior corneal astigmatism on total cornealastigmatism in eyes with moderate to high astigmatismrdquoJournal of Cataract and Refractive Surgery vol 40 no 10pp 1645ndash1653 2014

[24] N Ardjomand S Hau J C McAlister et al ldquoQuality of visionand graft thickness in deep anterior lamellar and penetratingcorneal allograftsrdquo American Journal of Ophthalmologyvol 143 no 2 pp 228ndash235 2007

[25] D Schiano-Lomoriello R Annamaria Colabelli-GisoldiM Nubile et al ldquoDescemetic and predescemetic dalk in

keratoconus patients a clinical and confocal perspectivestudyrdquo BioMed Research International vol 2014 Article ID123156 7 pages 2014

[26] K Naeser ldquoAssessment and statistics of surgically inducedastigmatismrdquo Actaophthalmologica vol 86 no 3 p 3492008

[27] G Savini K Naeser D Schiano-Lomoriello and P DucolildquoOptimized keratometry and total corneal astigmatism fortoric intraocular lens calculationrdquo Journal of Cataract ampRefractive Surgery vol 43 no 9 pp 1140ndash1148 2017

[28] V Scorcia A Lucisano V Savoca Corona V De LucaA Carnevali and M Busin ldquoDeep anterior lamellar kera-toplasty followed by toric lens implantation for the treatmentof concomitant anterior stromal diseases and cataractrdquoOphthalmology at Point of Care vol 1 no 1 articleoapoc0000008 2017

[29] G Savini and K Naeser ldquoAn analysis of the factors influ-encing the residual refractive astigmatism after cataractsurgery with toric intraocular lensesrdquo Investigative Oph-thalmology Visual Science vol 56 no 2 pp 827ndash835 2015

[30] B Acar C Utine S Acar and F Ciftci ldquoEndothelial cell lossafter phacoemulsification in eyes with previous penetratingkeratoplasty previous deep anterior lamellar keratoplasty orno previous surgeryrdquo Journal of Cataract and RefractiveSurgery vol 37 no 11 pp 2013ndash2017 2011

6 Journal of Ophthalmology

Stem Cells International

Hindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

MEDIATORSINFLAMMATION

of

EndocrinologyInternational Journal of

Hindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

Disease Markers

Hindawiwwwhindawicom Volume 2018

BioMed Research International

OncologyJournal of

Hindawiwwwhindawicom Volume 2013

Hindawiwwwhindawicom Volume 2018

Oxidative Medicine and Cellular Longevity

Hindawiwwwhindawicom Volume 2018

PPAR Research

Hindawi Publishing Corporation httpwwwhindawicom Volume 2013Hindawiwwwhindawicom

The Scientific World Journal

Volume 2018

Immunology ResearchHindawiwwwhindawicom Volume 2018

Journal of

ObesityJournal of

Hindawiwwwhindawicom Volume 2018

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Computational and Mathematical Methods in Medicine

Hindawiwwwhindawicom Volume 2018

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Hindawiwwwhindawicom Volume 2018

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Evidence-Based Complementary andAlternative Medicine

Volume 2018Hindawiwwwhindawicom

Submit your manuscripts atwwwhindawicom

average overcorrections of 003 (plusmn113) D and 036 (plusmn104) Dfor measurements based on preoperative and postoperativeTCA respectively Torsional powers disclosed averagecounterclockwise rotations amounting to 055plusmn 122D and034plusmn 179 D None of these meridional and torsional av-erage powers differed significantly from zero Figures 1 and 2show the distribution of individual and mean ERA based onboth preoperative and postoperative TCA measurementsERA mean absolute error (MAE) amounted to 143plusmn 091Dand 169plusmn 118D for preoperative and postoperative TCAmeasurements with no statistically significant differencebetween them (e postoperative endothelial cell reductionwas 8 compared to preoperative values No patients hadpostoperative corneal decompensation

4 Discussion

Our results show that cataract extraction with toric IOLimplantation is effective to reduce astigmatism and improvevisual acuity in patients with previous DALK Postoperative

improvements of UDVA CDVA and astigmatism were allstatistically significant Previous studies reported the effec-tiveness of toric IOL s implantation in eyes with previous PK[8ndash15] A retrospective study recently published on a peer-reviewed but not indexed journal describes good outcomesfor toric IOLs in eyes with previous DALK [28] Our dataconfirm these results as shown by the significant im-provement of UDVA and CDVA and add some interestingfindings related to vector analysis (which was not carried outby Scorcia et al) [28] In our sample the refractive pre-dictability was good as in 90 of patients the postoperativerefractive astigmatism was within 2 D and on average morethan 75 of astigmatismmagnitude was corrected(e goodoutcomes can be related to two factors at least First the toricIOLwas customized that is manufactured in steps of 025Daccording to the axial length and corneal astigmatism valuesthat we supplied preoperatively Moreover the cylinderpower of the IOL could be manufactured to correct as manyas more than 9 D which is not possible with standard toricIOLs Second calculations were based on TCA rather thanon KA as the former has been shown to provide more

Table 2 Meridional and torsional power of preoperative and postoperative total corneal astigmatism and the surgically induced cornealastigmatism (SICA)

Meridional power Torsional powerPreoperative minus011plusmn 360 052 minus487 to 438 minus193plusmn 372 minus271 minus670 to 348Postoperative 016plusmn 410 minus032 minus572 to 738 minus170plusmn 403 minus238 minus1015 to 316p value 06953 06953SICA 027plusmn 116 028 minus086 to +300 023plusmn 144 012 minus200 to +242SICA is defined as the difference between preoperative and postoperative total corneal astigmatism Each entity is reported as average (plusmnSD) median minimalvaluendashmaximal value All units are in diopters (D)

0000

ndash10

ndash20

ndash30

ndash40

10

20

30

ndash10ndash20ndash30ndash40 10

Meridional polar value in diopters

Tors

iona

l pol

ar v

alue

s in

diop

ters

ERA from preoperative TCA

20 30

Figure 1 (e error in refractive astigmatism (ERA) in calculationsbased on preoperatively measured total corneal astigmatism(TCA)X-axis ERA expressed as themeridional polar value Y-axisERA expressed as the torsional polar value (e small colored dotsindicate the individual observations (e large black dots indicatethe combined mean (centroid)

Meridional polar values in diopters

Tors

iona

l pol

ar v

alue

s in

diop

ters

ERA from postoperative TCA

00

ndash10

ndash20

ndash30

ndash40

10

20

30

ndash10ndash20ndash30ndash40 10 20 3000

Figure 2 (e error in refractive astigmatism (ERA) in calculationsbased on postoperatively measured total corneal astigmatism(TCA)X-axis ERA expressed as themeridional polar value Y-axisERA expressed as the torsional polar value (e small colored dotsindicate the individual observations (e large black dots indicatethe combined mean (centroid)

4 Journal of Ophthalmology

accurate results [29] Vector analysis showed that using bothpreoperative and postoperative TCA leads to a good pre-dictability in the refractive outcome as the average ERA wasclose to zero in both cases (e ERA standard deviations formeridional (plusmn113D) and torsional (plusmnD) powers should becompared to the approximateplusmn 060D values for normaleyes [29] (e relatively large variability may depend ona lower repeatability of TCA measurements in eyes withirregular astigmatism On the other hand the predictabilityof astigmatism correction in these eyes can be reduced due toany irregular component of corneal astigmatism whichcannot be corrected by toric IOLs and by the variable SICAinduced by the incision In this regard although vectoranalysis revealed a minimal average SICA (just 035D at 20deg)we should consider that this value is misleading as oppositeastigmatism is cancelled out by vector analysis A morerealistic value is provided by the range of the meridional(from minus086 to +300D) and torsional (from minus200 to+242D) power changes in corneal astigmatism whichhighlight the risk of TCA changes induced by the incision(e SICA standard deviations for meridional and torsionalpower in normal eyes were recently reported asplusmn 040Dandplusmn 048D [29] which is far less than the similar valuesofplusmn 116D andplusmn 144D in the present series Usually sur-gery induces a corneal flattening along the surgical meridianand a compensatory steepening along its orthogonal me-ridian the so-called coupling effect [26] In the presentstudy a 027D steepening was observed (is average resultwas influenced by a 30D corneal steepening in a single eyewith a preoperative TCA of 932D However corneal bio-mechanics are obviously changed after DALK surgerywhich may explain the absence of the normal averageflattening We also found a good rotational stability of thetoric IOL since in no case the misalignment of the main axisof the IOL with respect to the 0ndash180deg axis was higher than 10degat the last follow-up (ese results are in good agreementwith previous studies on toric IOLs only in eyes with PK[11 12] As a secondary outcome we observed that allsurgeries were safe and well tolerated by the corneal en-dothelium During the follow-up period there were nopostoperative complications of the grafts No episodes ofimmune-mediated rejection or other complications poten-tially compromising the VA were recorded [30]

Readers may be concerned about the mean age of oursample (671plusmn 73 years) as this means that our patients didnot undergo DALK in their 20s or 30s as it usually happensbut in their 50s or 60s (e surgical indication at this age wasmainly due to contact lens intolerance or progressive visualimpairment

(is study has some limitations that warrant furtherinvestigations First the sample size was small Second wecompared the preoperative TCA to the postoperative re-fractive astigmatism in order to evaluate the reduction of theastigmatism magnitude (is is not an ideal method becauseit compares values obtained from different measurements(Scheimpflug imaging of the cornea versus refraction)However due to the presence of cataract the measurementof the preoperative refractive astigmatism would not bereliable so that total corneal astigmatism seems to be the

best parameter for comparisons In conclusion our resultssuggest that toric IOL implantation after cataract surgery inpatients previously treated with DALK represents a safe andeffective procedure for the correction of astigmatism

Data Availability

All relevant data are available from the ldquoFondazione GBBiettirdquo for researchers who meet the criteria for access toconfidential data

Conflicts of Interest

(e authors declare that there are no conflicts of interestregarding the publication of this paper

Acknowledgments

(is study was supported by the Italian Ministry of Healthand Fondazione Roma

References

[1] A Vail S M Gore B A Bradley D L Easty C A Rogersand W J Armitage ldquoConclusions of the corneal transplantfollow up studyrdquo British Journal of Ophthalmology vol 81no 8 pp 631ndash636 1997

[2] P S Binder ldquo(e effect of suture removal on postkeratoplastyastigmatismrdquo American Journal of Ophthalmology vol 105no 6 pp 637ndash645 1988

[3] S Feizi and M Zare ldquoCurrent approaches for management ofpostpenetrating keratoplasty astigmatismrdquo Journal of Oph-thalmology vol 2011 Article ID 708736 8 pages 2011

[4] M R Mandel M B Shapiro and J H Krachmer ldquoRelaxingincisions with augmentation sutures for the correction ofpostkeratoplasty astigmatismrdquo American Journal of Oph-thalmology vol 103 no 3 pp 441ndash447 1987

[5] K Bilgihan S C Ozdek F Akata and B HasanreisogluldquoPhotorefractive keratectomy for post-penetrating kerato-plasty myopia and astigmatismrdquo Journal of Cataract amp Re-fractive Surgery vol 26 no 11 pp 1590ndash1595 2000

[6] K Buzard J-L Febbraro and B R Fundingsland ldquoLaser insitu keratomileusis for the correction of residual ametropiaafter penetrating keratoplastyrdquo Journal of Cataract ampRe-fractive Surgery vol 30 no 5 pp 1006ndash1013 2004

[7] J C D Arantes S Coscarelli P Ferrara L P N AraujoM Avila and L Torquetti ldquoIntrastromal corneal ring seg-ments for astigmatism correction after deep anterior lamellarkeratoplastyrdquo Journal of Ophthalmology vol 2017 Article ID8689017 7 pages 2017

[8] M Wade R F Steinert S Garg M Farid and R GasterldquoResults of toric intraocular lenses for post-penetrating ker-atoplasty astigmatismrdquo Ophthalmology vol 121 no 3pp 771ndash777 2014

[9] N Visser R Ruız-Mesa F Pastor N J C BauerR M M A Nuijts and R Montes-Mico ldquoCataract surgerywith toric intraocular lens implantation in patients with highcorneal astigmatismrdquo Journal of Cataract and RefractiveSurgery vol 37 no 8 pp 1403ndash1410 2011

[10] S Srinivasan D S J Ting and D A M Lyall ldquoImplantation ofa customized toric intraocular lens for correction of post-keratoplasty astigmatismrdquoEye vol 27 no 4 article 531537 2013

Journal of Ophthalmology 5

[11] CM Stewart and J C McAlister ldquoComparison of grafted andnon-grafted patients with corneal astigmatism undergoingcataract extraction with a toric intraocular lens implantrdquoClinical ampExperimental Ophthalmology vol 38 no 8pp 747ndash757 2010

[12] U De Sanctis C Eandi and F Grignolo ldquoPhacoemulsifi-cation and customized toric intraocular lens implantation ineyes with cataract and high astigmatism after penetratingkeratoplastyrdquo Journal of Cataract and Refractive Surgeryvol 37 no 4 pp 781ndash785 2011

[13] D Lockington E Wang D V Patel S P Moore andC N J McGhee ldquoEffectiveness of cataract phacoemulsifi-cation with toric intraocular lenses in addressing astigmatismafter keratoplastyrdquo Journal of Cataract Refractive Surgeryvol 40 no 12 pp 2044ndash2049 2014

[14] I Klftuoglu Y A Akova S Egrilmez and S G Yilmaz ldquo(eresults of toric intraocular lens implantation in patients withcataract and high astigmatism after penetrating keratoplastyrdquoC vol 42 no 2 pp e8ndashe11 2016

[15] L Kessel J Andresen B Tendal D Erngaard P Flesner andJ Hjortdal ldquoToricintraocular lenses in the correction ofastigmatism during cataract surgery a systematic review andmeta-analysisrdquo Ophthalmology vol 123 no 2 pp 275ndash2862016

[16] M Anwar ldquoIndication to deep anterior lamellar keratoplastyrdquoin Cornea Surgery of the Cornea and Conjunctiva ElsevierInc New York NY USA 2013

[17] M Anwar and K D Teichmann ldquoBig-bubble technique tobare descemetrsquos membrane in anterior lamellar keratoplastyrdquoJournal of Cataract ampRefractive Surgery vol 28 no 3pp 398ndash403 2002

[18] V M Borderie A Werthel O Touzeau C AllouchS Boutboul and L Laroche ldquoComparison of techniques usedfor removing the recipient stroma in anterior lamellar ker-atoplastyrdquo Archives of Ophthalmology vol 126 no 1pp 31ndash37 2008

[19] S L Watson A Ramsay J K G Dart C Bunce and E CraigldquoComparison of deep lamellar keratoplasty and penetratingkeratoplasty in patients with keratoconusrdquo Ophthalmologyvol 111 no 9 pp 1676ndash1682 2004

[20] R Macintyre S-P Chow E Chan and A Poon ldquoLong-termoutcomes of deep anterior lamellar keratoplasty versuspenetrating keratoplasty in Australian keratoconus patientsrdquoCornea vol 33 no 1 pp 6ndash9 2014

[21] J H Krumeich A Knlle and B M Krumeich ldquodeep anteriorlamellar (dalk) vs penetrating keratoplasty (pkp) a clinicaland statistical analysisrdquo Klinische Monatsblatter fur Augen-heilkunde vol 225 no 7 pp 637ndash648 2008

[22] A Kandar ldquoCombined special capsular tension ring andtoriciol implantation for management of post-dalk highregular astigmatism with subluxated traumatic cataractrdquoIndian Journal of Ophthalmology vol 62 no 7 pp 819ndash8222014

[23] G Savini F Versaci G Vestri P Ducoli and K Nr ldquoIn-fluence of posterior corneal astigmatism on total cornealastigmatism in eyes with moderate to high astigmatismrdquoJournal of Cataract and Refractive Surgery vol 40 no 10pp 1645ndash1653 2014

[24] N Ardjomand S Hau J C McAlister et al ldquoQuality of visionand graft thickness in deep anterior lamellar and penetratingcorneal allograftsrdquo American Journal of Ophthalmologyvol 143 no 2 pp 228ndash235 2007

[25] D Schiano-Lomoriello R Annamaria Colabelli-GisoldiM Nubile et al ldquoDescemetic and predescemetic dalk in

keratoconus patients a clinical and confocal perspectivestudyrdquo BioMed Research International vol 2014 Article ID123156 7 pages 2014

[26] K Naeser ldquoAssessment and statistics of surgically inducedastigmatismrdquo Actaophthalmologica vol 86 no 3 p 3492008

[27] G Savini K Naeser D Schiano-Lomoriello and P DucolildquoOptimized keratometry and total corneal astigmatism fortoric intraocular lens calculationrdquo Journal of Cataract ampRefractive Surgery vol 43 no 9 pp 1140ndash1148 2017

[28] V Scorcia A Lucisano V Savoca Corona V De LucaA Carnevali and M Busin ldquoDeep anterior lamellar kera-toplasty followed by toric lens implantation for the treatmentof concomitant anterior stromal diseases and cataractrdquoOphthalmology at Point of Care vol 1 no 1 articleoapoc0000008 2017

[29] G Savini and K Naeser ldquoAn analysis of the factors influ-encing the residual refractive astigmatism after cataractsurgery with toric intraocular lensesrdquo Investigative Oph-thalmology Visual Science vol 56 no 2 pp 827ndash835 2015

[30] B Acar C Utine S Acar and F Ciftci ldquoEndothelial cell lossafter phacoemulsification in eyes with previous penetratingkeratoplasty previous deep anterior lamellar keratoplasty orno previous surgeryrdquo Journal of Cataract and RefractiveSurgery vol 37 no 11 pp 2013ndash2017 2011

6 Journal of Ophthalmology

Stem Cells International

Hindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

MEDIATORSINFLAMMATION

of

EndocrinologyInternational Journal of

Hindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

Disease Markers

Hindawiwwwhindawicom Volume 2018

BioMed Research International

OncologyJournal of

Hindawiwwwhindawicom Volume 2013

Hindawiwwwhindawicom Volume 2018

Oxidative Medicine and Cellular Longevity

Hindawiwwwhindawicom Volume 2018

PPAR Research

Hindawi Publishing Corporation httpwwwhindawicom Volume 2013Hindawiwwwhindawicom

The Scientific World Journal

Volume 2018

Immunology ResearchHindawiwwwhindawicom Volume 2018

Journal of

ObesityJournal of

Hindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

Computational and Mathematical Methods in Medicine

Hindawiwwwhindawicom Volume 2018

Behavioural Neurology

OphthalmologyJournal of

Hindawiwwwhindawicom Volume 2018

Diabetes ResearchJournal of

Hindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

Research and TreatmentAIDS

Hindawiwwwhindawicom Volume 2018

Gastroenterology Research and Practice

Hindawiwwwhindawicom Volume 2018

Parkinsonrsquos Disease

Evidence-Based Complementary andAlternative Medicine

Volume 2018Hindawiwwwhindawicom

Submit your manuscripts atwwwhindawicom

accurate results [29] Vector analysis showed that using bothpreoperative and postoperative TCA leads to a good pre-dictability in the refractive outcome as the average ERA wasclose to zero in both cases (e ERA standard deviations formeridional (plusmn113D) and torsional (plusmnD) powers should becompared to the approximateplusmn 060D values for normaleyes [29] (e relatively large variability may depend ona lower repeatability of TCA measurements in eyes withirregular astigmatism On the other hand the predictabilityof astigmatism correction in these eyes can be reduced due toany irregular component of corneal astigmatism whichcannot be corrected by toric IOLs and by the variable SICAinduced by the incision In this regard although vectoranalysis revealed a minimal average SICA (just 035D at 20deg)we should consider that this value is misleading as oppositeastigmatism is cancelled out by vector analysis A morerealistic value is provided by the range of the meridional(from minus086 to +300D) and torsional (from minus200 to+242D) power changes in corneal astigmatism whichhighlight the risk of TCA changes induced by the incision(e SICA standard deviations for meridional and torsionalpower in normal eyes were recently reported asplusmn 040Dandplusmn 048D [29] which is far less than the similar valuesofplusmn 116D andplusmn 144D in the present series Usually sur-gery induces a corneal flattening along the surgical meridianand a compensatory steepening along its orthogonal me-ridian the so-called coupling effect [26] In the presentstudy a 027D steepening was observed (is average resultwas influenced by a 30D corneal steepening in a single eyewith a preoperative TCA of 932D However corneal bio-mechanics are obviously changed after DALK surgerywhich may explain the absence of the normal averageflattening We also found a good rotational stability of thetoric IOL since in no case the misalignment of the main axisof the IOL with respect to the 0ndash180deg axis was higher than 10degat the last follow-up (ese results are in good agreementwith previous studies on toric IOLs only in eyes with PK[11 12] As a secondary outcome we observed that allsurgeries were safe and well tolerated by the corneal en-dothelium During the follow-up period there were nopostoperative complications of the grafts No episodes ofimmune-mediated rejection or other complications poten-tially compromising the VA were recorded [30]

Readers may be concerned about the mean age of oursample (671plusmn 73 years) as this means that our patients didnot undergo DALK in their 20s or 30s as it usually happensbut in their 50s or 60s (e surgical indication at this age wasmainly due to contact lens intolerance or progressive visualimpairment

(is study has some limitations that warrant furtherinvestigations First the sample size was small Second wecompared the preoperative TCA to the postoperative re-fractive astigmatism in order to evaluate the reduction of theastigmatism magnitude (is is not an ideal method becauseit compares values obtained from different measurements(Scheimpflug imaging of the cornea versus refraction)However due to the presence of cataract the measurementof the preoperative refractive astigmatism would not bereliable so that total corneal astigmatism seems to be the

best parameter for comparisons In conclusion our resultssuggest that toric IOL implantation after cataract surgery inpatients previously treated with DALK represents a safe andeffective procedure for the correction of astigmatism

Data Availability

All relevant data are available from the ldquoFondazione GBBiettirdquo for researchers who meet the criteria for access toconfidential data

Conflicts of Interest

(e authors declare that there are no conflicts of interestregarding the publication of this paper

Acknowledgments

(is study was supported by the Italian Ministry of Healthand Fondazione Roma

References

[1] A Vail S M Gore B A Bradley D L Easty C A Rogersand W J Armitage ldquoConclusions of the corneal transplantfollow up studyrdquo British Journal of Ophthalmology vol 81no 8 pp 631ndash636 1997

[2] P S Binder ldquo(e effect of suture removal on postkeratoplastyastigmatismrdquo American Journal of Ophthalmology vol 105no 6 pp 637ndash645 1988

[3] S Feizi and M Zare ldquoCurrent approaches for management ofpostpenetrating keratoplasty astigmatismrdquo Journal of Oph-thalmology vol 2011 Article ID 708736 8 pages 2011

[4] M R Mandel M B Shapiro and J H Krachmer ldquoRelaxingincisions with augmentation sutures for the correction ofpostkeratoplasty astigmatismrdquo American Journal of Oph-thalmology vol 103 no 3 pp 441ndash447 1987

[5] K Bilgihan S C Ozdek F Akata and B HasanreisogluldquoPhotorefractive keratectomy for post-penetrating kerato-plasty myopia and astigmatismrdquo Journal of Cataract amp Re-fractive Surgery vol 26 no 11 pp 1590ndash1595 2000

[6] K Buzard J-L Febbraro and B R Fundingsland ldquoLaser insitu keratomileusis for the correction of residual ametropiaafter penetrating keratoplastyrdquo Journal of Cataract ampRe-fractive Surgery vol 30 no 5 pp 1006ndash1013 2004

[7] J C D Arantes S Coscarelli P Ferrara L P N AraujoM Avila and L Torquetti ldquoIntrastromal corneal ring seg-ments for astigmatism correction after deep anterior lamellarkeratoplastyrdquo Journal of Ophthalmology vol 2017 Article ID8689017 7 pages 2017

[8] M Wade R F Steinert S Garg M Farid and R GasterldquoResults of toric intraocular lenses for post-penetrating ker-atoplasty astigmatismrdquo Ophthalmology vol 121 no 3pp 771ndash777 2014

[9] N Visser R Ruız-Mesa F Pastor N J C BauerR M M A Nuijts and R Montes-Mico ldquoCataract surgerywith toric intraocular lens implantation in patients with highcorneal astigmatismrdquo Journal of Cataract and RefractiveSurgery vol 37 no 8 pp 1403ndash1410 2011

[10] S Srinivasan D S J Ting and D A M Lyall ldquoImplantation ofa customized toric intraocular lens for correction of post-keratoplasty astigmatismrdquoEye vol 27 no 4 article 531537 2013

Journal of Ophthalmology 5

[11] CM Stewart and J C McAlister ldquoComparison of grafted andnon-grafted patients with corneal astigmatism undergoingcataract extraction with a toric intraocular lens implantrdquoClinical ampExperimental Ophthalmology vol 38 no 8pp 747ndash757 2010

[12] U De Sanctis C Eandi and F Grignolo ldquoPhacoemulsifi-cation and customized toric intraocular lens implantation ineyes with cataract and high astigmatism after penetratingkeratoplastyrdquo Journal of Cataract and Refractive Surgeryvol 37 no 4 pp 781ndash785 2011

[13] D Lockington E Wang D V Patel S P Moore andC N J McGhee ldquoEffectiveness of cataract phacoemulsifi-cation with toric intraocular lenses in addressing astigmatismafter keratoplastyrdquo Journal of Cataract Refractive Surgeryvol 40 no 12 pp 2044ndash2049 2014

[14] I Klftuoglu Y A Akova S Egrilmez and S G Yilmaz ldquo(eresults of toric intraocular lens implantation in patients withcataract and high astigmatism after penetrating keratoplastyrdquoC vol 42 no 2 pp e8ndashe11 2016

[15] L Kessel J Andresen B Tendal D Erngaard P Flesner andJ Hjortdal ldquoToricintraocular lenses in the correction ofastigmatism during cataract surgery a systematic review andmeta-analysisrdquo Ophthalmology vol 123 no 2 pp 275ndash2862016

[16] M Anwar ldquoIndication to deep anterior lamellar keratoplastyrdquoin Cornea Surgery of the Cornea and Conjunctiva ElsevierInc New York NY USA 2013

[17] M Anwar and K D Teichmann ldquoBig-bubble technique tobare descemetrsquos membrane in anterior lamellar keratoplastyrdquoJournal of Cataract ampRefractive Surgery vol 28 no 3pp 398ndash403 2002

[18] V M Borderie A Werthel O Touzeau C AllouchS Boutboul and L Laroche ldquoComparison of techniques usedfor removing the recipient stroma in anterior lamellar ker-atoplastyrdquo Archives of Ophthalmology vol 126 no 1pp 31ndash37 2008

[19] S L Watson A Ramsay J K G Dart C Bunce and E CraigldquoComparison of deep lamellar keratoplasty and penetratingkeratoplasty in patients with keratoconusrdquo Ophthalmologyvol 111 no 9 pp 1676ndash1682 2004

[20] R Macintyre S-P Chow E Chan and A Poon ldquoLong-termoutcomes of deep anterior lamellar keratoplasty versuspenetrating keratoplasty in Australian keratoconus patientsrdquoCornea vol 33 no 1 pp 6ndash9 2014

[21] J H Krumeich A Knlle and B M Krumeich ldquodeep anteriorlamellar (dalk) vs penetrating keratoplasty (pkp) a clinicaland statistical analysisrdquo Klinische Monatsblatter fur Augen-heilkunde vol 225 no 7 pp 637ndash648 2008

[22] A Kandar ldquoCombined special capsular tension ring andtoriciol implantation for management of post-dalk highregular astigmatism with subluxated traumatic cataractrdquoIndian Journal of Ophthalmology vol 62 no 7 pp 819ndash8222014

[23] G Savini F Versaci G Vestri P Ducoli and K Nr ldquoIn-fluence of posterior corneal astigmatism on total cornealastigmatism in eyes with moderate to high astigmatismrdquoJournal of Cataract and Refractive Surgery vol 40 no 10pp 1645ndash1653 2014

[24] N Ardjomand S Hau J C McAlister et al ldquoQuality of visionand graft thickness in deep anterior lamellar and penetratingcorneal allograftsrdquo American Journal of Ophthalmologyvol 143 no 2 pp 228ndash235 2007

[25] D Schiano-Lomoriello R Annamaria Colabelli-GisoldiM Nubile et al ldquoDescemetic and predescemetic dalk in

keratoconus patients a clinical and confocal perspectivestudyrdquo BioMed Research International vol 2014 Article ID123156 7 pages 2014

[26] K Naeser ldquoAssessment and statistics of surgically inducedastigmatismrdquo Actaophthalmologica vol 86 no 3 p 3492008

[27] G Savini K Naeser D Schiano-Lomoriello and P DucolildquoOptimized keratometry and total corneal astigmatism fortoric intraocular lens calculationrdquo Journal of Cataract ampRefractive Surgery vol 43 no 9 pp 1140ndash1148 2017

[28] V Scorcia A Lucisano V Savoca Corona V De LucaA Carnevali and M Busin ldquoDeep anterior lamellar kera-toplasty followed by toric lens implantation for the treatmentof concomitant anterior stromal diseases and cataractrdquoOphthalmology at Point of Care vol 1 no 1 articleoapoc0000008 2017

[29] G Savini and K Naeser ldquoAn analysis of the factors influ-encing the residual refractive astigmatism after cataractsurgery with toric intraocular lensesrdquo Investigative Oph-thalmology Visual Science vol 56 no 2 pp 827ndash835 2015

[30] B Acar C Utine S Acar and F Ciftci ldquoEndothelial cell lossafter phacoemulsification in eyes with previous penetratingkeratoplasty previous deep anterior lamellar keratoplasty orno previous surgeryrdquo Journal of Cataract and RefractiveSurgery vol 37 no 11 pp 2013ndash2017 2011

6 Journal of Ophthalmology

Stem Cells International

Hindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

MEDIATORSINFLAMMATION

of

EndocrinologyInternational Journal of

Hindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

Disease Markers

Hindawiwwwhindawicom Volume 2018

BioMed Research International

OncologyJournal of

Hindawiwwwhindawicom Volume 2013

Hindawiwwwhindawicom Volume 2018

Oxidative Medicine and Cellular Longevity

Hindawiwwwhindawicom Volume 2018

PPAR Research

Hindawi Publishing Corporation httpwwwhindawicom Volume 2013Hindawiwwwhindawicom

The Scientific World Journal

Volume 2018

Immunology ResearchHindawiwwwhindawicom Volume 2018

Journal of

ObesityJournal of

Hindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

Computational and Mathematical Methods in Medicine

Hindawiwwwhindawicom Volume 2018

Behavioural Neurology

OphthalmologyJournal of

Hindawiwwwhindawicom Volume 2018

Diabetes ResearchJournal of

Hindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

Research and TreatmentAIDS

Hindawiwwwhindawicom Volume 2018

Gastroenterology Research and Practice

Hindawiwwwhindawicom Volume 2018

Parkinsonrsquos Disease

Evidence-Based Complementary andAlternative Medicine

Volume 2018Hindawiwwwhindawicom

Submit your manuscripts atwwwhindawicom

[11] CM Stewart and J C McAlister ldquoComparison of grafted andnon-grafted patients with corneal astigmatism undergoingcataract extraction with a toric intraocular lens implantrdquoClinical ampExperimental Ophthalmology vol 38 no 8pp 747ndash757 2010

[12] U De Sanctis C Eandi and F Grignolo ldquoPhacoemulsifi-cation and customized toric intraocular lens implantation ineyes with cataract and high astigmatism after penetratingkeratoplastyrdquo Journal of Cataract and Refractive Surgeryvol 37 no 4 pp 781ndash785 2011

[13] D Lockington E Wang D V Patel S P Moore andC N J McGhee ldquoEffectiveness of cataract phacoemulsifi-cation with toric intraocular lenses in addressing astigmatismafter keratoplastyrdquo Journal of Cataract Refractive Surgeryvol 40 no 12 pp 2044ndash2049 2014

[14] I Klftuoglu Y A Akova S Egrilmez and S G Yilmaz ldquo(eresults of toric intraocular lens implantation in patients withcataract and high astigmatism after penetrating keratoplastyrdquoC vol 42 no 2 pp e8ndashe11 2016

[15] L Kessel J Andresen B Tendal D Erngaard P Flesner andJ Hjortdal ldquoToricintraocular lenses in the correction ofastigmatism during cataract surgery a systematic review andmeta-analysisrdquo Ophthalmology vol 123 no 2 pp 275ndash2862016

[16] M Anwar ldquoIndication to deep anterior lamellar keratoplastyrdquoin Cornea Surgery of the Cornea and Conjunctiva ElsevierInc New York NY USA 2013

[17] M Anwar and K D Teichmann ldquoBig-bubble technique tobare descemetrsquos membrane in anterior lamellar keratoplastyrdquoJournal of Cataract ampRefractive Surgery vol 28 no 3pp 398ndash403 2002

[18] V M Borderie A Werthel O Touzeau C AllouchS Boutboul and L Laroche ldquoComparison of techniques usedfor removing the recipient stroma in anterior lamellar ker-atoplastyrdquo Archives of Ophthalmology vol 126 no 1pp 31ndash37 2008

[19] S L Watson A Ramsay J K G Dart C Bunce and E CraigldquoComparison of deep lamellar keratoplasty and penetratingkeratoplasty in patients with keratoconusrdquo Ophthalmologyvol 111 no 9 pp 1676ndash1682 2004

[20] R Macintyre S-P Chow E Chan and A Poon ldquoLong-termoutcomes of deep anterior lamellar keratoplasty versuspenetrating keratoplasty in Australian keratoconus patientsrdquoCornea vol 33 no 1 pp 6ndash9 2014

[21] J H Krumeich A Knlle and B M Krumeich ldquodeep anteriorlamellar (dalk) vs penetrating keratoplasty (pkp) a clinicaland statistical analysisrdquo Klinische Monatsblatter fur Augen-heilkunde vol 225 no 7 pp 637ndash648 2008

[22] A Kandar ldquoCombined special capsular tension ring andtoriciol implantation for management of post-dalk highregular astigmatism with subluxated traumatic cataractrdquoIndian Journal of Ophthalmology vol 62 no 7 pp 819ndash8222014

[23] G Savini F Versaci G Vestri P Ducoli and K Nr ldquoIn-fluence of posterior corneal astigmatism on total cornealastigmatism in eyes with moderate to high astigmatismrdquoJournal of Cataract and Refractive Surgery vol 40 no 10pp 1645ndash1653 2014

[24] N Ardjomand S Hau J C McAlister et al ldquoQuality of visionand graft thickness in deep anterior lamellar and penetratingcorneal allograftsrdquo American Journal of Ophthalmologyvol 143 no 2 pp 228ndash235 2007

[25] D Schiano-Lomoriello R Annamaria Colabelli-GisoldiM Nubile et al ldquoDescemetic and predescemetic dalk in

keratoconus patients a clinical and confocal perspectivestudyrdquo BioMed Research International vol 2014 Article ID123156 7 pages 2014

[26] K Naeser ldquoAssessment and statistics of surgically inducedastigmatismrdquo Actaophthalmologica vol 86 no 3 p 3492008

[27] G Savini K Naeser D Schiano-Lomoriello and P DucolildquoOptimized keratometry and total corneal astigmatism fortoric intraocular lens calculationrdquo Journal of Cataract ampRefractive Surgery vol 43 no 9 pp 1140ndash1148 2017

[28] V Scorcia A Lucisano V Savoca Corona V De LucaA Carnevali and M Busin ldquoDeep anterior lamellar kera-toplasty followed by toric lens implantation for the treatmentof concomitant anterior stromal diseases and cataractrdquoOphthalmology at Point of Care vol 1 no 1 articleoapoc0000008 2017

[29] G Savini and K Naeser ldquoAn analysis of the factors influ-encing the residual refractive astigmatism after cataractsurgery with toric intraocular lensesrdquo Investigative Oph-thalmology Visual Science vol 56 no 2 pp 827ndash835 2015

[30] B Acar C Utine S Acar and F Ciftci ldquoEndothelial cell lossafter phacoemulsification in eyes with previous penetratingkeratoplasty previous deep anterior lamellar keratoplasty orno previous surgeryrdquo Journal of Cataract and RefractiveSurgery vol 37 no 11 pp 2013ndash2017 2011

6 Journal of Ophthalmology

Stem Cells International

Hindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

MEDIATORSINFLAMMATION

of

EndocrinologyInternational Journal of

Hindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

Disease Markers

Hindawiwwwhindawicom Volume 2018

BioMed Research International

OncologyJournal of

Hindawiwwwhindawicom Volume 2013

Hindawiwwwhindawicom Volume 2018

Oxidative Medicine and Cellular Longevity

Hindawiwwwhindawicom Volume 2018

PPAR Research

Hindawi Publishing Corporation httpwwwhindawicom Volume 2013Hindawiwwwhindawicom

The Scientific World Journal

Volume 2018

Immunology ResearchHindawiwwwhindawicom Volume 2018

Journal of

ObesityJournal of

Hindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

Computational and Mathematical Methods in Medicine

Hindawiwwwhindawicom Volume 2018

Behavioural Neurology

OphthalmologyJournal of

Hindawiwwwhindawicom Volume 2018

Diabetes ResearchJournal of

Hindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

Research and TreatmentAIDS

Hindawiwwwhindawicom Volume 2018

Gastroenterology Research and Practice

Hindawiwwwhindawicom Volume 2018

Parkinsonrsquos Disease

Evidence-Based Complementary andAlternative Medicine

Volume 2018Hindawiwwwhindawicom

Submit your manuscripts atwwwhindawicom

Stem Cells International

Hindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

MEDIATORSINFLAMMATION

of

EndocrinologyInternational Journal of

Hindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

Disease Markers

Hindawiwwwhindawicom Volume 2018

BioMed Research International

OncologyJournal of

Hindawiwwwhindawicom Volume 2013

Hindawiwwwhindawicom Volume 2018

Oxidative Medicine and Cellular Longevity

Hindawiwwwhindawicom Volume 2018

PPAR Research

Hindawi Publishing Corporation httpwwwhindawicom Volume 2013Hindawiwwwhindawicom

The Scientific World Journal

Volume 2018

Immunology ResearchHindawiwwwhindawicom Volume 2018

Journal of

ObesityJournal of

Hindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

Computational and Mathematical Methods in Medicine

Hindawiwwwhindawicom Volume 2018

Behavioural Neurology

OphthalmologyJournal of

Hindawiwwwhindawicom Volume 2018

Diabetes ResearchJournal of

Hindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

Research and TreatmentAIDS

Hindawiwwwhindawicom Volume 2018

Gastroenterology Research and Practice

Hindawiwwwhindawicom Volume 2018

Parkinsonrsquos Disease

Evidence-Based Complementary andAlternative Medicine

Volume 2018Hindawiwwwhindawicom

Submit your manuscripts atwwwhindawicom