ARTICLE

Capsulorhexis contraction after cataract surgery:Comparison of sharp anterior edge and modified

anterior edge acrylic intraocular lensesCharlotte Corydon, MD, Michael Lindholt, MD, Ellen B. Knudsen, MD, Jesper Graakjaer, PhD,

Thomas J. Corydon, PhD, Mikael Dam-Johansen, PhD

PURPOSE: To evaluate the reduction in the anterior capsule opening after phacoemulsification, con-tinuous curvilinear capsulorhexis, and implantation of 1 of 2 acrylic intraocular lenses (IOLs).

SETTING: Department of Ophthalmology, Vejle Hospital, Vejle, Denmark.

METHODS: Eighty-four patients (84 eyes) were included in a prospective randomized study. All hadphacoemulsification followed by implantation of an IOL with a modified anterior edge (38 eyes) ora sharp anterior edge (46 eyes). One day (baseline) and 3 months postoperatively, the area of theanterior capsule opening was measured using retroillumination photographs.

RESULTS: There was a significant reduction in the area of the anterior capsule opening from 1 dayto 3 months postoperatively in both groups (P<.001). There was no significant difference in thereduction in the anterior capsule opening between the modified-edge IOL and the sharp-edged IOL(P Z .313). The shrinkage was independent of the area of the anterior capsule opening at baseline.

CONCLUSIONS: There was a reduction in the area of the anterior capsule opening in all patients. Thedesign of the anterior edge of the 2 IOLs did not influence the degree of anterior capsule openingshrinkage. The shrinkage was independent of the size of the area 1 day postoperatively.

J Cataract Refract Surg 2007; 33:796–799 Q 2007 ASCRS and ESCRS

For many years, a continuous curvilinear capsulo-rhexis (CCC)1 has been used in cataract surgery. Onecomplication of CCCs is contraction of the capsuleopening,2–4 which can cause decreased vision if it in-terferes with the visual axis. The contraction prog-resses during the first 3 months after surgery, afterwhich it stabilizes.3,5,6 Most intraocular lenses (IOLs)have a sharp posterior edge to prevent posterior

Accepted for publication January 14, 2007.

From the Department of Ophthalmology (Corydon, Lindholt, Knud-sen, Dam-Johansen), Vejle Hospital, Vejle, and the Institute of Hu-man Genetics (Graakjaer, Corydon), University of Aarhus, Aarhus,Denmark.

No author has a financial or proprietary interest in any material ormethod mentioned.

Presented at the ASCRS Symposium on Cataract, IOL and Refrac-tive Surgery, San Francisco, California, USA, March 2006.

Corresponding author: Charlotte Corydon, MD, Solbakken 1.D.3,8240 Risskov, Denmark. E-mail: cco@dadlnet.dk.

Q 2007 ASCRS and ESCRS

Published by Elsevier Inc.

796

capsule opacification.7,8 Most also have a sharp ante-rior edge, which can cause glare problems.9 Thismightbe why modifications have been made to the anterioredge. However, we have observed cases of anteriorcapsule contraction in eyes with IOLs that havemodified anterior edges. This study was performedto determine whether there is a difference in anteriorcapsule contraction between an acrylic IOL witha sharp anterior edge and an acrylic IOL with a modi-fied anterior edge.

PATIENTS AND METHODS

One hundred patients were included in a prospective ran-domized clinical trial to examine the anterior capsule open-ing after implantation of a Sensar AR40e OptiEdge IOL(AMO) or an AcrySof MA60AC Monoflex IOL (Alcon).Table 1 shows the specifications of the IOLs. Althoughboth IOLs have a sharp posterior edge, the Sensar AR40ehas a modified anterior edge and the AcrySof MA60AChas a sharp anterior edge.

All patients were enrolled in the study at Vejle Hospital.The inclusion criteria were older than 60 years, no ocularpathology other than cataract, a dilated pupil larger than7.0 mm, axial length between 21.0 mm and 25.0 mm, and

0886-3350/07/$dsee front matter

doi:10.1016/j.jcrs.2007.01.020

797CAPSULORHEXIS CONTRACTION: SHARP-EDGED VERSUS MODIFIED EDGE IOL

informed consent. Exclusion criteria were intraoperativecomplications, CCC without total IOL overlap, and diabetesmellitus.

The local ethics committee approved the study protocol,and all patients provided informed consent. The patientswere randomized before cataract surgery to the IOL witha modified anterior edge or the IOL with a sharp anterioredge. Four surgeons performed all surgeries using thesame surgical procedure and topical anesthesia. Phacoemul-sification was through a clear corneal temporal incision. Af-ter sodium hyaluronate 3%–chondroitin sulfate 4% withsodium hyaluronate 1% (DuoVisc) was injected into the an-terior chamber, a CCC slightly smaller than the IOL opticwas created to attain a 360-degree capsulorhexis–IOL over-lap. After hydrodissection, hydrodelineation, and phaco-emulsification, cortex aspiration and posterior capsulepolishing were performed. DuoVisc was injected into thebag, and the IOL was implanted. The DuoVisc was thenaspirated.

The area of the anterior capsule opening was measured1 day and 3 months after surgery. Retroillumination photo-graphs of the anterior capsule opening were taken witha Zeiss slitlamp with a digital camera. All measurements

Table 1. Intraocular lens specifications.

Characteristic

Sensar AR40eOptiEdge(AMO)

AcrySof MA60ACMonoflex(Alcon)

Overall length (mm) 13.0 13.0

OpticDiameter (mm) 6.0 6.0Material Acrylic AcrylicDesign Biconvex Biconvex

Modified Sharp

HapticConfiguration Modified C Modified CMaterial PMMA PMMAPosteriorangulation(degrees)

5 10

J CATARACT REFRACT S

were repeated 3 times, and the mean values were used.The area of the anterior capsule opening was measuredfrom the area of the IOL, which was known. The areaswere measured in pixels with the Zeiss Visupac 121 system.

Statistical AnalysisStatistical analysis was by the paired t test, t test, Levene

test, and Pearson correlation test using SPSS software (ver-sion 13.0, SPSS, Inc.). A 95% confidence interval was usedfor paired and independent samples t tests. The Levenetest was used to test for equality of variances and the Pearsoncorrelation test, for linear relationships.

RESULTS

Table 2 shows the patients’ characteristics. Of the 100patients enrolled, 10 were lost to follow-up. In addi-tion, 3 patients were excluded because the capsulo-rhexis was not entirely on the optic and 3 because ofinsufficient photographs. The remaining 84 patientscompleted the follow-up examinations.

Figure 1 shows the area of the anterior capsule open-ing at the 3-month follow-up as function of the area at1 day. The opening decreased significantly in both IOLgroups during the follow-up (P!.0001, paired t test),and all CCC areas were smaller after 3 months thanat 1 day. The area of the anterior capsule openingwas not significantly different between the 2 groupsat 1 day (P Z .959, t test) or after 3 months (P Z.577, t test). Figure 2 shows the mean area reductionafter 3 months, which was 2.2 mm2 G 1.4 (SD) in theSensar AR40e group and 1.9 G 1.4 mm2 in the AcrySofMA60AC group. There was a significant reduction inthe area of the anterior capsule opening at 3 monthscompared with 1 day in both groups. However, therewas no significant difference in shrinkage of the ante-rior capsule between the 2 groups (P Z .313, t test).

Analysis of the ratio of the mean percentage reduc-tion and the CCC area at 1 day showed no correlationbetween the CCC area at 1 day and the reduction in

Table 2. Patients’ characteristics.

CharacteristicSensar AR40e OptiEdge

(AMO)AcrySof MA60AC Monoflex

(ALCON) P Value*

Number of patients 38 46 d

Mean age (years) 72.2 71.0 d

Sex d

Female 24 24Male 14 22

Mean area (mm2) G SD1 day 17.97 G 1.80 17.94 G 2.01 .9593 months 15.74 G 2.20 16.04 G 2.55 .577

P value (area: 1 day vs 3 months) !.0001 !.0001 d

*Sensar versus AcrySof

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798 CAPSULORHEXIS CONTRACTION: SHARP-EDGED VERSUS MODIFIED EDGE IOL

the anterior capsule opening (Figure 3) (r Z 0.01and P Z .473, Sensar AR40e; r Z �0.13 and P Z .235,AcrySof MA60AC).

DISCUSSION

This study found a significant reduction in the anteriorcapsule opening 3 months after cataract surgery withCCC, a finding that has been reported in previous stud-ies.3,5,6 Several factors, such as IOL opticmaterial, opticdesign, haptic material, and haptic design, have beeninvestigated to determine whether they influenceshrinkage of the anterior capsule opening.2,10,11 Ofthese, only optic material (silicone) has been shown tosignificantly affect the degree of anterior capsulecontraction.3,6,12 Other factors, such as individual,pathological, and surgical conditions, havebeen shownto influence anterior capsule contraction. This is seen incases of high myopia, uveitis, pseudoexfoliation, myo-tonic dystrophy, retinitis pigmentosa, advanced age,and zonular dehiscence during surgery.13–15

Fibrous anterior capsule contraction is seen in thepart of the capsule facing the anterior surface of the op-tic.16,17 We therefore speculate that fibrous dysplasiaof residual lens epithelial cells on the capsule facingthe anterior surface of the IOL would be more pro-nounced with the IOL with the modified anterioredge than with the IOL with the sharp anterior edge

Figure 1. Area at 1 day versus 3 months.

0.0

1.0

2.0

3.0

4.0

Mean

area red

uctio

n (m

m2)

Sensar AR40eAcrysof MA60AC

P = 0.313

2.2

± 1.4

1.9

± 1.4

Figure 2. Comparison of the mean reduction in the anterior capsuleopening area with standard deviations after 3 months.

J CATARACT REFRACT SU

because the cells would migrate more easily over themodified edge. Our results show no significant differ-ence in shrinkage of the anterior capsule openingbetween the IOLwith the sharp anterior edge (AcrySofMA60AC) and the IOL with a modified anterior edge(Sensar AR40e). In addition, 1 day postoperatively,anterior capsule shrinkage was not correlated withthe area of the anterior capsule opening.

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