INTRODUCTION

Presbyopia is a common visual disability caused by theloss of accommodation of the crystalline lens due to thenormal eye aging process. The number of presbyopicpatients is expected to reach 20.1 million patients world-wide by 2020. Therefore, an increase in the demand forspectacles independence lead to the increased interest inthe development of novel treatments to correct presby-opia surgically [1].

Until now there is no solution to restore full accom-

modation and all the current techniques manage to im-prove near vision at the price of either reduced distancevision, or loss of stereopsis, or reduction in quality of vi-sion (reduced contrast sensitivity, halos and glare).

Surgical procedures for correction of presbyopia couldbe divided into:

1. Multifocal IOL which is the most widespread andeffective solution.

2. Corneal inlays [Inlays with small-aperture optics(KAMRA), refractive optic inlays (Flexivue Micro-lens and ICOLENS) and reshaping inlays (the rain-drop inlay)].

3. Other less proven procedures: accommodative IOL,monovision or blended vision strategies, conduc-tive keratoplasty, presbyLASIK, intrastromal cor-rection with the use of femtosecond technology(INTRACOR, Technolas, Perfect Vision GmbH),scleral expansion techniques.

The KAMRA design (ACI7000PDT) (Acufocus Inc.,Irvine, CA, USA) consists of a 3.8 mm diameter micro-perforated (8,400 holes 5-11 µm in diameter) tinted discwith 1.6 mm central aperture at 6 µm thickness and ismade of polyvinylidene fluoride and carbon nanopar-ticles [2]. It compensates for the progressive loss of

Lebanese Medical Journal 2018 • Volume 66 (5) 275

CCAASS CCLLIINNIIQQUUEE// CCAASSEE RREEPPOORRTTMATURE CATARACT IN A KAMRA INLAY IMPLANTED EYEhttp://www.lebanesemedicaljournal.org/articles/66-5/case1.pdf

Abdo KHOURY1, Wassef CHANBOUR2, Liliane NASSAR3

Khoury A, Chanbour W, Nassar L. Mature cataract in a KAMRAinlay implanted eye. J Med Liban 2018 ; 66 (5) : 275-278.

Khoury A, Chanbour W, Nassar L. Cararacte mûre dans un œil avecun implant intracornéen KAMRA. J Med Liban 2018 ; 66 (5) : 275-278.

ABSTRACT • KAMRA inlay has become a well-known cor-neal implant which is used in the treatment of presbyopia,thousands of implants were inserted due to the increaseddemand on spectacles independence in the new era of re-fractive surgery. Ophthalmologists will face a dilemma ifthese patients present for a cataract surgery.

This is a case report of a unilateral mature cataract in aneye that had previously undergone FEMTO-LASIK refractivesurgery with KAMRA insertion; there were no changes in thesurgical technique, except for few ocular rotations to improvevisualisation. Contact A-scan biometry was used and Sham-mas-no history formula was effective in calculating thepower of the intraocular lens, but Haigis and Hoffer Q formu-las were more accurate.

Even though the implant was recentered and the patientcomplained of dry eyes prior to the cataract surgery, thepatient preserved her original visual acuities and no com-plications occurred both during and post phacoemulsifica-tion.

Keywords : KAMRA, cataract, FEMTOsecondLASIK, pres-byopia

RÉSUMÉ • KAMRA inlay est devenu un implant cornéen bienconnu qui est utilisé dans le traitement de la presbytie. Desmilliers d’implants ont été insérés en raison de la demandeaccrue de l’indépendance aux lunettes dans la nouvelle èrede chirurgie réfractive. Les ophtalmologistes seront confron-tés à un dilemme si ces patients présentent une cataracte.

Nous rapportons un cas de cataracte mature unilatéraledans un œil qui avait précédemment bénéficié d’une chirurgieréfractive FEMTO-LASIK avec insertion KAMRA; il n’y avait au-cun changement dans la technique chirurgicale, à l’exceptionde quelques rotations oculaires pour améliorer la visualisationperopératoire. La biométrie A-scan a été utilisée et la formulede Shammas était efficace pour calculer la puissance de lalentille intraoculaire, néanmoins les formules Haigis et HofferQ étaient plus précises. Les résultats postopératoires étaientsatisfaisants avec une récupération de l’acuité visuelle préca-taracte. Aucune complication per- ou postopératoire n’a étérapportée en dehors de la nécessité de recentrer l’implantainsi qu’une sécheresse oculaire modérée.

Mots-clés : KAMRA, cataracte, FEMTOsecond-LASIK,presbytie

1Department of Ophthalmology, Clinique du Levant hospital,Holy Spirit University of Kaslik, Lebanon.

2Beirut Eye and ENT Specialist hospital, Lebanon. 3Optometrist, Clinique du Levant hospital.

*Corresponding author: Wassef Chanbour, MD.e-mail: wassef_c@hotmail.com

AbbreviationsUDVA: uncorrected distance visual acuityCDVA: corrected distance visual acuityUNVA: uncorrected near visual acuityCNVA: corrected near visual acuity

IOL: intra-ocular lens

accommodative amplitude [1]. Up-to-date 18000 inlayswere implanted worldwide [1], and it was FDA approvedon April 2015 [3].

Since the marketing on 2005, there were few pub-lished cases of patients developing cataract and undergo-ing phacoemulsification after implantation of KAMRAbecause it is a new technology implanted in phakic pa-tients and their age group is 40 to 65 years. In the follow-ing years, the ophthalmologists will face in their clinicsa larger number of eyes implanted with KAMRA andhaving a cataract, so it is important to know the opera-tive options and to be prepared to face the technical dif-ficulties.

CASE REPORT

A 53-year-old female patient underwent in 2013 Femto-second-LASIK (Ziemer LDV) (Ziemer Ophthalmic Sys-tems AG, Port, Switzerland) treatment for hyperopia andastigmatism (Table I), with insertion of KAMRA inlayunder the flap in the non-dominant eye. Repositioning ofthe inlay was necessary 4 months later for decreasedvisual acuity after nasal decentration of the inlay showedon AcuTarget (Figure 1). Anterior chamber and retinalexam were normal and Preoperative GALILEI (Dualscheimpflug analyser) (V4.01 Ziemer, Port, Switzerland)is shown in Figure 2.

The 9 mm flap was opened at the depth of 110 mi-crons in the right eye and 200 microns in the left, fol-lowed by a Laser treatment (Schwind Amaris eye- tech-solutions, SmartSurf) of OD:+2.5 D (-0.5 D *70)/OS:+3.75 D (-0.75 D *90) (addition of +1.00 D in theleft eye to enhance the near vision). Postoperative medi-cations: Prednisolone acetate eye drops for one weekfollowed by Loteprednol tapered over 3 months, in addi-tion to ofloxacine and artificial tears.

The patient had been started on cyclosporine eyedrops due to ocular dryness and her near visual acuity

was 20/32 (0.625). She was satisfied with her distant andintermediate vision but, she needed an addition of +1.5Dto assist in her excessive near work.

Two years later the patient had a decrease in the VAover few months in the left eye (light perception), amature white cataract grade 4+ was noted (Figure 3).

Two surgical options were discussed: either, to re-move the KAMRA followed by phacoemulsification andinsertion of a multifocal IOL or to do the phacoemulsifi-cation with the KAMRA in place. The decision was to dothe cataract surgery only. Biometry was performed usingcontact Ultrasound A-scan (TOMEY, UD-600) and IOLpower calculation was done using Shammas-no historyformula, Lenstar hill RBF calculator aiming for a targetpower between -1.00 and -1.50D (Table II).

Under local anaesthesia, 3.2 temporal corneal incisionwas done (the only one available blade size in the hospital)followed by an uneventful cataract phacoemulsificationand implantation of +19.5 D mono-focal i-Medical®

276 Lebanese Medical Journal 2018 • Vol 66 (5) A. KHOURY et al. – KAMRA and cataract

TABLE IVISUAL ACUITIES Pre-/Post-KAMRA, Pre-/Post-REPOSITIONING & Pre-/Post-CATARACT SURGERY*

2 weeks Before After Pre- 2 monthsPre-KAMRA after recentration recentration cataract post-cataract

KAMRA surgery surgery

OD OS Binocular Binocular Binocular OS OD OS

UDVA 0.2 0.16 0.9 0.9 0.9 LP 0.9 0.5

CDVA 0.9 0.9 0.9

Manifest refraction +2.25 (-0.5*70)D +2.75 (-0.75*90)D plano - 1.00D

UNVA 0.125 0.625 0.125 0.625 0.625

CNVA 1 1 1

Near correction Addition + 2.5D Addition + 2.5D + 1.5D + 1.5D + 1.5D

*Decimal numbers are used LP: light perception

Figure 1. AcuTarget photos Pre-KAMRA, Decentred-KAMRA,Post-recentration and Post-cataract

i-Flex intraocular lens and suturing of the incision.The surgery time was 15 minutes. In the absence of a

red reflex, Tryptan blue was used prior to capsulorrhexisdue to the advanced white cataract. The second hand wasused to rotate the eye and improve visualisation duringcapsulorrhexis and phaco-emulsification (Figure 3).

Postoperative medications were Prednisolone acetate4 drops/day followed by 1 month taper, Ketorolac (1 month)and Azithromycin (3 days).

Upon follow-up, two months post-op, corneal suturewas removed, binocular UDVA was 20/22 (0.9) and UNVAwas 20/32 (0.625) which were similar to the post KAMRAinsertion acuities. The patient still needed an addition of+1.5 D for excessive near work (Table I). Postoperativetopography using Opticon corneal wavefront analyser(Figure 2) and Acutarget (Figure 1) were stable.

DISCUSSION

Since the implantation of KAMRA inlays has started,there are few reported cases of patients undergoingcataract surgery with the implant in place and there is nofinal consensus regarding the surgical options, the com-plications and difficulties during the phacoemulsifica-tion, preoperative IOL calculations and the postoperativevisual acuity.

A. KHOURY et al. – KAMRA and cataract Lebanese Medical Journal 2018 • Vol 66 (5) 277

Figure 2. GALILEI pre-KAMRA & TOPOGRAPHY post-cataract

Figure 3. OPERATIVE view OS during cataract surgery and slit lamp view day 1 post-op

TABLE IIBIOMETRY MEASUREMENTS OS, SHAMMAS-NO HISTORY FORMULA

USING I-FLEX IOL, LENSTAR HILL RBF CALCULATOR

I-Flex / I-Medical A: 118.40 Manual entry Previous femto-Shammas-no history formula biometry LASIK treatment

IOL Eye (D) AL: 22.85 mm Sphere: + 3.50

18.00 - 0.31 CCT: 557 microns Cylinder: - 0.75

18.50 -0.67 AD: 2.60 mm Axe: 90

19.00 -1.02 ACD: 3.16 mm

19.50 -1.38 R1: 46.96 D @4

20.00 -1.73 R2:47.45 D @94

R: 47.20 DA: constant AL: axial length CCT: central corneal thickness AD: aqueous depthACD: anterior chamber depth

Our patient had a severe corneal dryness and reopeningthe flap for the second time may have exacerbated hersymptoms and risked more flap complications. Tien-EnTan et al., reported two cases of non-complicated cataractsurgery following KAMRA implant and the patients pre-operative and postoperative UNVA were similar [4].

No major changes in the cataract surgical techniquewere reported, the optimal visualisation was achieved byrotating the eye using the second instrument. Also, alarger capsulorhexis was purposely done to avoid theshadow of the inlay measuring 3.8 mm which may coverthe border of the capsulorhexis and increase the risk ofcomplication during phacoemulsification. Tan T [4] andWaltz K [5] reported also the ease of the surgery in atotal of four patients using the same operative techniquewithout any difficulty. There was no loss of visual acu-ity lines indicating that the implant location and effectare not affected by the surgery.

LENSTAR LS 900 (HAAG-STREIT DIAGNOSTICS)failed to measure the biometry mostly because it was adense cataract. But, the contact A-scan readings were sat-isfactory and the Shammas-no history formula by Hill-RBF calculator was used because the patient had a priorrefractive surgery and gave an accurate IOL power (pre-operative target -1.38D, postoperative refraction -1.00 D)the -1.38D was chosen in order to gain an optimal nearacuity without affecting the distance binocular vision, withpostoperative error of 0.38D.

Postoperative analysis showed that for the same IOLpower (19.5D) the target eye refraction in other formu-las would be -0.49D (SRK/T) with a difference of 0.51from the achieved refraction, -1.03D (Hoffer Q) with adifference of 0.03D and -1.05D (Haigis) with a differ-ence of 0.05D, -1.34D (ASCRS post refractive IOL cal-culator) with a difference of 0.34D. Therefore, Haigisand Hoffer Q formulas were the most accurate. MajidMoshirfar et al. had a mean difference in target and

achieved IOL power of 0.32 D ± 0.31D using SRK/Tformula [6].

CONCLUSION

In conclusion, patients with KAMRA inlay implantedeyes have the option to undergo a cataract surgery andretain the benefits of the KAMRA without losing theirUNVA. The surgery was reported to be easy and compa-rable to regular surgeries.

In our case report there were no specific complicationsrelated to the presence of the inlay. Contact A-scan wasable to measure the biometry. Even though Shammasformula was effective in predicting the postoperativerefraction other formulas may be more accurate, largernumber of cases are needed to assess the effectiveness ofthese methods in calculating the IOL powers.

REFERENCES

1. Agarwal A, Thomas J. Mastering Corneal Surgery.Thorofare: SLACK, 2015: 263-8.

2. Naroo S, Bilkhu P. Clinical utility of the KAMRA cor-neal inlay. Clinical Ophthalmology 2016; 10: 913-19.

3. FDA approves first-of-its-kind corneal implant to im-prove near vision in certain patients, 2017.Available at: http://www.fda.gov/NewsEvents/Newsroom/Press Announcements/ucm443471.htm. Accessed January6, 2017.

4. Tan T, Mehta J. Cataract surgery following KAMRApresbyopic implant. Clinical Ophthalmology 2013; 1899.doi:10.2147/opth.s52182

5. Waltz K. IOL implantation after a KAMRA cornealinlay procedure. CRSTEurope. https://crstodayeurope.com/articles/2012-sep/iol-implantation-after-a-kamra-corneal-inlay-procedure/. Published 2012. Accessed December 5, 2018

6. Moshirfar M, Quist T, Skanchy D et al. Cataract surgeryin patients with a previous history of KAMRA inlay im-plantation: A case series. Ophthalmol Ther 2017; 6 (1):207-13.

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