A systematic overview of the incidence of posterior capsule opacification

Two-photon absorption-controlled multidose drug release: a novel approach for secondary cataract treatment

Tens of millions of cataract surgeries are done every year and the number is increasing heavily. Posterior capsule opacification is the major postoperative complication with an incidence of 10 to 50% within 5 years, depending on the age of the patient. We present a novel approach for secondary cataract treatment in a noninvasive manner. Photochemically triggered drug release from a polymer enables repeated drug applications for cataract treatment years after implantation of the intraocular lens, just when needed. However, light in the visible spectral range must pass through the lens but must not induce drug release. We demonstrate that two-photon absorption photochemistry is a powerful tool to overcome this problem. With wavelengths in the visible regime, a photochemical reaction that requires energies in the UV is triggered. The high intensities needed for this process never occur in any lighting condition in daily lives, but may be easily obtained with focused laser beams routinely used in ophthalmology. The properties of the therapeutic system are specified and the function is demonstrated by in-vitro cell tests. Noninvasive multidose photochemically triggered drug release from implanted intraocular lenses carrying a drug depot may be a therapeutic as well as an economic choice to established treatments of secondary cataracts.

Effect of posterior capsular opacification removal on scanning laser polarimetry measurements

PURPOSE

To evaluate the effect of posterior capsular opacification (PCO) on retinal nerve fiber layer (RNFL) retardation measurements obtained during scanning laser polarimetry (SLP). We are unaware of previous studies undertaken in this sense.

METHODS

SLP was performed using GDx variable corneal compensation (VCC) on 28 eyes of 28 non-glaucomatous patients with clinically significant PCO, previous uneventful cataract surgery and no other ocular pathology, both before and after Nd:YAG capsulotomy. Best-corrected visual acuity (BCVA), intraocular pressure (IOP) and SLP examination parameters prior and following PCO removal were compared using the Student t-test and Wilcoxon's test. Spearman correlations between BCVA and SLP measurements before and after capsulotomy were also performed.

RESULTS

PCO removal was associated with an increase of BCVA (P<0.0001), nerve fiber indicator (NFI) (P<0.0001) and typical scan score (TSS) (P<0.0001). In parallel, significant decreases of all absolute parameters were observed after capsulotomy. IOP, symmetry, superior ratio, inferior ratio and temporal-superior-nasal-inferior-temporal (TSNIT) standard deviation (SD) revealed no changes. Before capsulotomy, marked correlation existed between the BCVA and some SLP measurements such as nasal average (r= -0.703; P<0.0001) or NFI (r= 0.564; P=0.0017). After PCO removal these correlations were no longer found.

CONCLUSIONS

PCO removal changes SLP measurements. Therefore, new measurements to serve as a baseline for future comparisons should be obtained after Nd:YAG capsulotomy. Furthermore, some SLP measurements were significantly associated with BCVA before capsulotomy, suggesting that this technology may be useful to quantify PCO degree in non-glaucomatous patients.

Effect of optic material and haptic design on anterior capsule opacification and capsulorrhexis contraction

PURPOSE

To examine the influence of optic material (silicone and hydrophobic acrylic) and haptic design (one-piece and three-piece open loop) of sharp optic edge intraocular lenses (IOL) on anterior capsule opacification (ACO) and capsulorrhexis contraction.

DESIGN

Randomized, controlled, double-blind clinical trial with intraindividual comparison.

METHODS

This study was performed at the Department of Ophthalmology, Medical University of Vienna, Austria, and comprised 210 eyes of 105 patients with bilateral age-related cataract. In group 1 (n = 53 patients), a three-piece acrylic IOL was compared with a three-piece silicone IOL. In group 2 (n = 52 patients), the three-piece acrylic IOL was compared with the one-piece acrylic IOL. One year after the operation, standardized digital slit-lamp images of ACO were taken; 1 week and 1 year after the operation, digital retroillumination images were taken to assess capsulorrhexis size. The intensity of ACO was graded objectively (score, 0% to 100%), and the capsulorrhexis area (square millimeters) was determined objectively.

RESULTS

One year after surgery, the mean ACO score was 21% for the acrylic and 20% for the silicone IOL (P = .4) in group 1 and 18% for both the three-piece and one-piece acrylic IOLs (P = .87) in group 2. Concerning the amount of capsulorrhexis contraction, there was no significant difference between the IOL types that were evaluated in this study (after Bonferroni-Holm correction, P > .05).

CONCLUSION

In the hydrophobic sharp optic edge IOLs that were examined, neither the optic material nor the haptic design had an influence on the amount of ACO or capsulorrhexis contraction.

Intraocular lens decentration and posterior capsule opacification: anatomo-pathologic findings after implantation of AMOSI40 IOLS

PURPOSE

To evaluate the incidence of intraocular lens (IOL) decentration and posterior capsule opacification (PCO) after implantation of a three-piece posterior chamber silicone IOL in a series of eyes examined postmortem.

METHODS

Twenty-three pseudophakic enucleated human cadaver eyes, implanted with AMO SI40NB IOLs after phacoemulsification, were analyzed. Eyes obtained postmortem were sectioned at the equatorial plane and the anterior segment photographed from a posterior view. Location of IOL optic and haptics, type of fixation, and centration of IOL was evaluated. PCO was graded and the presence of Nd:YAG laser posterior capsulotomy was noted.

RESULTS

Mean age at the time of surgery was 77.83 years, mean time since implantation was 18.26 months. In all the eyes examined, IOL haptics were positioned in the capsular bag. Mean decentration was 0.20+/-0.16 mm. No correlation was found between IOL decentration and time since implantation. The degree of peripheral PCO ranged from none (13.0%) to mild (39.1%) to moderate (26.1%) to severe (21.7%). The degree of central PCO ranged from none (52.2%) to mild (30.4%) to moderate (4.3%). Three patients (13.0%) underwent Nd:YAG laser posterior capsulotomy.

CONCLUSIONS

A very good centration can be obtained when silicone AMOSI40NB IOLs are correctly implanted with the haptics inside the capsular bag. About half of the implants showed no central PCO while Nd:YAG laser posterior capsulotomy rates documented a relatively low PCO 18 months after surgery. A careful in the bag haptics placement is needed in order to reduce the IOL decentration and to prevent central PCO.

Rapid onset and progression of posterior capsular opacification

Posterior capsular opacification is a common complication following extracapsular cataract surgery. Its time of onset after surgery, rate of development and affect on vision vary greatly from one individual to another. In this case report, we describe the rapid development of posterior subcapsular opacification over a 12-day period. This occurred four years after extracapsular cataract extraction and intraocular lens implantation via the technique of phako-emulsification.

Quantitative Nachstarevaluierung von Acrylat- und Silikonintraokularlinsen mit scharfem Kantendesign

BACKGROUND

At the Department of Ophthalmology, Heidelberg, Germany, posterior capsule opacification (PCO) of a silicone and an acrylic intraocular lens (IOL) with a sharp optic edge design was evaluated.

PATIENTS AND METHODS

In a prospective study either the AMO ClariFlex silicone IOL or the Sensar AR40e hydrophobic acrylic IOL were implanted in 47 patients following uneventful phacoemulsification. Mean patient age was 76.2+/-7.8 (ClariFlex) and 73.4+/-12.9 years (AR40e), respectively. The mean follow-up time was 19.7+/-5.34 in the ClariFlex and 21.9+/-1.89 months in the AR40e group. PCO development was evaluated postoperatively using the EPCO 2000 analysis software (scale 0-4). Areas of interest were the total IOL optic, the central 3-mm zone as well as the capsulorhexis.

RESULTS

In both groups, all patients achieved a BCVA of 20/32 (AR40e) and 20/25 (ClariFlex), respectively. There was a very low incidence of PCO development with a mean EPCO score of 0.07+/-0.2 (ClariFlex and 0.15+/-0.2 (AR40e). Within the 3-mm zone and the capsulorhexis, there was a tendency for even lower EPCO scores in both groups. We calculated a statistically significant difference for the two lens materials for all investigated IOL areas (Wilcoxon's test, p<0.05).

CONCLUSION

Both IOLs with a sharp edge design showed good functional results, a stable position in the capsular bag as well as a low incidence of PCO development. However, the silicone IOL showed statistically significantly lower PCO scores.

Posterior capsule opacification-like changes in rat lens explants cultured with TGFbeta and FGF: effects of cell coverage and regional differences

Following cataract surgery, many patients suffer secondary loss of vision because of posterior capsule opacification (PCO), which arises when residual lens epithelial cells become aberrant and migrate into the light path. Transforming growth factor-beta (TGFbeta)-induced transdifferentiation of lens cells appears to play a key role in this process. Fibroblast growth factor (FGF) may also play a role by promoting the survival of TGFbeta-affected cells and influencing their subsequent behaviour. In the present study, the effects of two different TGFbeta and FGF treatment regimes were compared in rat lens epithelial explants with either low or high initial cell coverage. Explants treated with 50 pg ml(-1) TGFbeta2 and 20 ng ml(-1) FGF-2 sequentially (day 0, day 1) or simultaneously (day 0), then cultured for up to 30 days with FGF, were assessed by light microscopy and immunolocalisation of markers for transdifferentiation (alpha-smooth muscle actin (alphaSMA) and type I collagen) or lens epithelial phenotype (Pax6) and fibre differentiation (beta-crystallin). By day 4, most cells had lost Pax6 reactivity, alphaSMA reactivity was evident, and there were differences between growth factor treatment groups, low and high initial cell coverage explants, and peripheral and central regions of explants. On day 30 of culture, all explants were well populated with cells, irrespective of treatment and initial cell coverage, and exhibited diverse PCO-like morphological changes, with expression of transdifferentiation markers and beta-crystallin in virtually all cells. Such overall resilience to variations in conditions may contribute to the insidious nature of PCO, while factors related to observed early differences between groups may contribute to PCO pleiomorphism.

Long-term Effect of Sharp Optic Edges of a Polymethyl Methacrylate Intraocular Lens on Posterior Capsule Opacification

PURPOSE

To compare the posterior capsule opacification (PCO) inhibiting effect of a 3-piece polymethyl methacrylate (PMMA) intraocular lens (IOL) with a sharp optic edge design with that of the round-edged version of the same IOL during a 5-year period.

DESIGN

Randomized patient- and examiner-masked clinical trial with intraindividual comparison.

PARTICIPANTS

Thirty-two patients with bilateral age-related cataract (64 eyes).

METHODS

Each study patient had phacoemulsification cataract surgery in both eyes and received a sharp optic edge PMMA IOL in one eye and a round optic edge PMMA IOL in the fellow eye (both by Dr Schmidt in Germany). Follow-up examinations were at 1 week, 1 month, 1 year, 3 years, and 5 years. Digital retroillumination images were taken from each eye. The amount of posterior capsule opacification was assessed objectively by means of automated image analysis software (Automated Quantification of After-Cataract) at 1 year, 3 years, and 5 years after surgery.

MAIN OUTCOME MEASURE

Posterior capsule opacification score: 0-10.

RESULTS

The sharp optic edge IOL showed significantly less regeneratory and fibrotic PCO at 1 year, 3 years, and 5 years after surgery. The mean AQUA PCO score was 5.12 for the round-edge and 2.49 for the sharp-edge IOL (scale, 0-10; P<0.001) at 5 years. The mean difference among patients for the PCO score in the eye implanted with the sharp optic edge versus the score in the eye with the round optic edge was 2.83 at 5 years (95% confidence interval, 1.66-4.00). Due to the large number of neodymium:yttrium-aluminum-garnet laser capsulotomies that were performed (12 in the round-edge group and 4 in the sharp-edge group), there was no significant difference in visual acuity between both groups at any time point.

CONCLUSIONS

Compared with the round-edge version, the sharp optic edge design of a 3-piece PMMA IOL led to significantly less PCO at 1 year, 3 years, and 5 years after surgery. However, the sharp optic edge did not lead to complete PCO prevention during this follow-up period. This finding has implications for the design of PMMA IOLs used for cataract surgery, especially in the developing world.

Evaluating and defining the sharpness of intraocular lenses

PURPOSE

To develop a new method for the evaluation of the optic edge design of intraocular lenses (IOLs).

SETTING

Charité Humboldt University and Berlin Eye Research Institute (Beri), Berlin, Germany.

METHODS

Poly(methyl methacrylate) IOLs with 11 edge designs were manufactured. Each lens design was evaluated using EPCO 2000. Also, edge's ability to stop cell growth was observed by placing each IOL into cell culture and observing cell growth over 18 days on average.

RESULTS

Only 3 groups, those with the sharpest edge design, prevented the growth of lens epithelial cells onto the visual axis of the lens. The edge design that effectively stopped cell growth was characterized by an area above the edge of 13.5 microm2 at the most.

CONCLUSION

Results shows that the edge design of IOLs plays an important role in the prevention of posterior capsule opacification. A specific optic edge design was most effective in this prevention.

Posterior capsular opacification affects scanning laser polarimetry examination

PURPOSE

To illustrate the effect of posterior capsular opacification (PCO) on retinal nerve fiber layer (RNFL) retardation measurements obtained during scanning laser polarimetry (SLP).

METHODS

SLP was performed using GDx VCC on three eyes of three non-glaucomatous patients with clinically significant PCO, before and after Nd:YAG capsulotomy.

RESULTS

PCO removal by Nd:YAG capsulotomy was associated with marked variations in retardation map morphology and with apparent RNFL thinning. Retardation map atypia decreased and typical scan score (TSS) increased remarkably after capsulotomy in all three cases.

CONCLUSION

An artifact introduced by PCO presence can affect SLP measurements reliability.

[New methods for the prevention of posterior capsule opacification]

Even though tremendous advances have been made especially during the last 10-15 years in terms of surgical techniques and improvement of implant technology, posterior capsule opacification (PCO) still remains a serious long-term complication. New clinical and laboratory studies (especially of autopsy eyes) have improved our understanding of how IOL design and material influence PCO. Sharp edge optic designs of IOLs of various materials have been shown to significantly reduce secondary cataract. The application of pharmacological substances selectively into the capsular bag is now possible due to the development of the PerfectCapsule System for vacuum-sealed capsule irrigation. Major advances in other areas of biotechnology and immunology including gene therapeutic methods offer totally new approaches for the future in the elimination of lens epithelium cells from the capsular bag. This survey gives an update on current and future means and trends to reduce or prevent PCO formation.

Short-term changes in the morphology of posterior capsule opacification

PURPOSE

To observe and document posterior capsule opacification (PCO) growth in vivo over a short period of time (4 weeks).

SETTING

Department of Ophthalmology, Medical University of Vienna, Vienna, Austria.

METHODS

Fifteen eyes of pseudophakic patients with PCO of varying degrees were included in this prospective study. Digital retroillumination images were taken in a standardized fashion at 3 time points: 1 baseline image, a second image after 2 weeks, and a third image after 4 weeks. Thus, a 3-image series could be created for each eye. Additionally, sections of the posterior capsule with interesting structures were photographed with higher magnification and compared in supplementary image series. Morphologic changes in the PCO structure (eg, number and size of Elschnig pearls, total PCO area) were analyzed in the image series.

RESULTS

In all cases, significant changes could be observed between the 3 time points. In 71% of cases, some Elschnig pearls increased in size during the first 2 weeks and during weeks 3 and 4. In 73% of cases, however, there was a reduction a pearl size or even disappearance of some Elschnig pearls. The total PCO area did not change significantly during the 4-week period.

CONCLUSIONS

Development of (regeneratory) PCO is a very dynamic process that includes not only growth of preexisting structures and occurrence of new Elschnig pearls, but also reorganization and even disappearance of pearls within a short time period (2-4 weeks). The latter in particular is not well known but could be observed in the majority of cases in this study.

Monocular diplopia after neodymium: YAG laser capsulotomy

PURPOSE

To present an unusual complication of posterior capsulotomy such as monocular diplopia and to discuss the importance of capsulotomy size.

METHODS

CASE REPORT

A 57-year old man came to our clinic complaining of horizontal monocular diplopia in his right eye for the past 3 days. The patient had undergone a Nd:YAG capsulotomy in this eye 3 weeks before. Slit-lamp biomicroscopy under pupil dilation revealed a small capsulotomy and a considerable Elschnig pearl as the presumable cause of the diplopia. The rest of the examination was completely normal.

RESULTS

After repeat Nd:YAG capsulotomy treatment, the diplopia disappeared.

CONCLUSION

Capsulotomy size is a significant factor to consider when treating a posterior capsular opacification. A capsulotomy that is larger than the pupil diameter under scotopic conditions may avoid disturbances of vision such as monocular diplopia.

Effect of posterior capsular opacification removal on automated perimetry

PURPOSE

Although posterior capsular opacification (PCO) is a common phenomenon in a considerable number of ophthalmologic patients, no prospective controlled trials assessing its influence on automated perimetry exist. This technique continues as a standard in the diagnosis of glaucoma and neuro-ophthalmological diseases. The aim of the present report is to investigate the effect of PCO on automated visual field examination.

METHODS

A total of 26 PCO affected eyes of 26 patients had Humphrey SITA standard (program 24-2) immediately before, and between 1 and 8 weeks after Neodymium : YAG capsulotomy. The effect of learning associated with repeated testing was controlled with automated perimetry before enrollment and visual fields of the fellow eye. Best-corrected visual acuity (BCVA), intraocular pressure (IOP), and global perimetric pre- and post-laser indices were compared using the Student's t-test for paired samples. Correlation and linear regression analyses were also performed.

RESULTS

BCVA and mean deviation (MD) improved following capsulotomy. Pattern standard deviation (PSD), an indicator of localized defects in the field, also improved significantly when PCO was solved. Moreover, a strong association among BCVA, MD, and PSD was shown both prior to and after capsulotomy.

CONCLUSION

PCO is a heterogeneous mean opacity. This polymorphism may alter visual field results, and may even simulate the perimetric behaviour of other pathologies such as glaucoma. Consequently, the presence of PCO should be considered in the interpretation of any automated perimetry in pseudophakic patients. In addition, the values obtained before capsulotomy may partially predict the values obtained after capsulotomy.

Long-term effect of optic edge design in an acrylic intraocular lens on posterior capsule opacification

PURPOSE

To compare the posterior capsule opacification (PCO) inhibiting effect of the sharp posterior optic edge design of the Sensar OptiEdge AR40e intraocular lens (IOL) with that of the double-round edge design of the Sensar AR40 IOL over a period of 3 years.

SETTING

Department of Ophthalmology, Medical University of Vienna, Vienna, Austria.

METHODS

Fifty-three patients with bilateral age-related cataract (106 eyes) were included in this randomized prospective bilateral patient- and examiner-masked clinical trial with intraindividual comparison. Each study patient had cataract surgery in both eyes and received a Sensar AR40 IOL (anterior and posterior round optic edges) in 1 eye and a Sensar OptiEdge AR40e IOL (round anterior and sharp posterior optic edge) in the other eye. Follow-up examinations were at 1 week, 1 and 6 months, and 1, 2, and 3 years. Digital retroillumination images were taken of each eye. The amount of PCO was assessed subjectively at the slitlamp and objectively using automated image-analysis software (AQUA) 1, 2, and 3 years after surgery.

RESULTS

The sharp-edged AR40e lens showed significantly less regeneratory and fibrotic PCO 1, 2, and 3 years after surgery. The mean AQUA PCO score was 2.18 for the AR40 and 1.00 for the AR40e lens after 1 year; 2.94 and 1.56 after 2 years, and estimated at 3.13 and 1.77, respectively, after 3 years (scale 0 to 10; P<.001). The neodymium:YAG laser capsulotomy rate was significantly higher in the AR40 group. The AR40e lens also led to less peripheral fibrotic PCO. There was no significant difference in complaints concerning edge glare between the groups.

CONCLUSION

Compared with the AR40 IOL, the sharp posterior optic edge design of the Sensar OptiEdge AR40e IOL led to significantly less PCO 1, 2, and 3 years postoperatively. In contrast with most past studies on PCO-preventative factors, this study varied only 1 parameter, namely the optic edge design, and the main outcome measure (PCO) was assessed with an objective image-analysis system.

Electrical inhibition of lens epithelial cell proliferation: an additional factor in secondary cataract?

Cataract is the most common cause of blindness but is at least curable by surgery. Unfortunately, many patients gradually develop the complication of posterior capsule opacification (PCO) or secondary cataract. This arises from stimulated cell growth within the lens capsule and can greatly impair vision. It is not fully understood why residual lens epithelial cell growth occurs after surgery. We propose and show that cataract surgery might remove an important inhibitory factor for lens cell growth, namely electric fields. The lens generates a unique pattern of electric currents constantly flowing out from the equator and entering the anterior and posterior poles. We show here that cutting and removing part of the anterior capsule as in cataract surgery significantly decreases the equatorial outward electric currents. Application of electric fields in culture inhibits proliferation of human lens epithelial cells. This inhibitory effect is likely to be mediated through a cell cycle control mechanism that decreases entry of cells into S phase from G1 phase by decreasing the G1-specific cell cycle protein cyclin E and increasing the cyclin-Cdk complex inhibitor p27kip1. Capsulorrhexis in vivo, which reduced endogenous lens electric fields, significantly increased LEC growth. This, together with our previous findings that electric fields have significant effects on the direction of lens cell migration, points to a controlling mechanism for the aberrant cell growth in posterior capsule opacification. A novel approach to control growth of lens epithelial cells using electric fields combined with other controlling mechanisms may be more effective in the prevention and treatment of this common complication of cataract surgery.

Association between intensity of posterior capsule opacification and visual acuity

PURPOSE

To investigate the correlation between the change in visual acuity and the difference in objective posterior capsule opacification (PCO) scores before and after neodymium:YAG (Nd:YAG) laser capsulotomy.

SETTING

Department of Ophthalmology, Medical University of Vienna, Vienna, Austria.

METHODS

Forty pseudophakic eyes of 35 patients with PCO of varying intensity were examined before and after Nd:YAG laser capsulotomy. Visual acuity was determined using the Early Treatment Diabetic Retinopathy Study (ETDRS) chart at 4 m and the Holladay reading chart at 40 cm. The pupil diameter under reading conditions was measured each time. Digital retroillumination images of the posterior capsule were taken, and the corresponding area inside the pupil was evaluated using the Automated Quantification of After-Cataract (AQUA) automated PCO analysis program. The change in visual acuity and difference between PCO scores before and after Nd:YAG laser capsulotomy were calculated for all eyes.

RESULTS

The mean AQUA score (scale 0 to 10) was 3.56 before and 0.13 after Nd:YAG laser capsulotomy. The mean ETDRS visual acuity score (logMAR scale) was 0.28 and -0.07, respectively. The correlation coefficient between the differences in PCO score and distance visual acuity was 0.61 and near visual acuity, 0.62.

CONCLUSIONS

The objective PCO score obtained by an automated image-analysis program correlates well with the PCO-induced decrease in visual acuity when the central area (inside the pupillary aperture) of the posterior lens capsule was evaluated. Objective PCO assessment by automated image-analysis systems is, therefore, a valuable and clinically relevant method for clinical studies of the development and prevention of PCO.

Three-year follow-up of posterior capsule opacification with two different silicone intraocular lenses

PURPOSE

To compare posterior capsule opacification (PCO) after cataract surgery with implantation of two silicone intraocular lenses (IOLs) with different designs.

METHODS

We carried out a prospective, clinical study of 116 patients randomized to standardized phacoemulsification with implantation of CeeOn Edge (n = 57) or SI40NB (n = 59) IOLs. The follow-up period was 3 years. To evaluate PCO morphologically, digital images were obtained and analysed using evaluation of posterior capsule opacification computer software (epco). The neodymium:YAG (Nd:YAG) capsulotomy rate was recorded.

RESULTS

At 2 and 3 years, the eyes with SI40NB IOLs had significantly more PCO than those with the CeeOn Edge IOLs (p = 0.00014 and p = 0.002). Nine Nd:YAG capsulotomies were performed in the SI40NB group and none in the CeeOn Edge group. This difference was statistically significant (p = 0.003). In some patients a regression of PCO was noticed and confirmed using epco. Statistically less PCO was noted when the capsulorhexis rim was placed so that it covered all 360 degrees of the optic of the IOL.

CONCLUSIONS

A clinically and statistically significant difference in PCO development between CeeOn Edge and SI40NB IOLs at 2 and 3 years postoperatively was found. These findings support earlier studies indicating that a sharp edge of the optic is a more important factor in IOL design than IOL material in the prevention of PCO.

The Effect of Capsular Tension Ring on Posterior Capsular Opacity in Cataract Surgery

This study was performed to evaluate the efficacy and safety of the capsular tension ring on posterior capsular opacity in comparison with cases undergoing intraocular lens (IOL) implantation alone. We analyzed 127 eyes which had undergone cataract surgery, including capsular tension ring insertion, along with 127 eyes which had undergone IOL implantation alone by the same surgeon from September 1998 to March 2003. In the insertion group, 41 eyes (group A) had been followed up for more than one year after silicone IOL implantation, as had 40 eyes (group B) in the control group. We compared the incidence, type, and degree of capsular opacity between A and B groups and also endothelial cell loss after surgery between the two groups. For insertion group A, the frequency of posterior capsular opacity was lower(7.3%), the duration to development was longer, and the energy required for Nd-Yag capsulotomy of PCO was less than for control group B (25%) (p=0.037). The endothelial cell count loss rate was not significantly different between the two groups (p=0.522). The capsular tension ring is associated with a significantly reduced incidence of posterior capsular opacity and is a safe procedure.

Free volume study on calcification process in an intraocular lens after cataract surgery

An opacified intraocular lens explanted from a patient in the postoperative period after phacoemulsification was investigated to find the cause of opacification. From the UV-visible and energy dispersive X-ray spectroscopy (EDS) measurements, the opacification in the present case seems to be due to calcification of the intraocular lens and not due to modification in the UV absorber material of the lens. The average free volume size of the intraocular lens both in unimplanted and explanted state were obtained from positron lifetime spectroscopy (PLS). Further, the combined FTIR and PLS results indicate that calcium gets into the free volume cavities of the intraocular lens matrix as a cationic moiety, may be in the form of Ca(++). The small decrease in glass transition temperature of the calcified lens seems to indicate the plasticizing action of calcium ions. The present results could be of some use in the design of the intraocular lens material in which calcification would be minimum.

Accommodation after Nd: YAG capsulotomy in patients with accommodative posterior chamber lens 1CU

PURPOSE

After initial encouraging results with the accommodative 1CU posterior chamber lens (PCIOL), we investigated the rate, the postoperative time point of posterior capsular opacification (PCO) necessitating YAG capsulotomy and the accommodative range after Nd: YAG capsulotomy in patients with 1CU-PCIOL.

PATIENTS AND METHODS

This prospective clinical study included 65 patients who underwent phacoemulsification and implantation of the accommodative 1CU-PCIOL with postoperative follow-up from 3 to 24 months. Postoperative examination was performed 3, 6 and 12 months after surgery, then before and 6 weeks after Nd: YAG capsulotomy. Measurements included: the best corrected distance visual acuity, distance refraction, near visual acuity (Birkhauser charts in 35 cm) obtained with best distance correction, accommodative range measured by subjective near point with an accodommometer and defocusing with a visual acuity fall to 0.4.

RESULTS

Both best corrected distance visual acuity (1.1+/-0.1) and near visual acuity with best distance correction (0.4+/-0.1) remained stable over the follow-up period until 12 months postoperatively. The accommodative range determined by near point was stable (mean 2.0+/-0.5 D). Also, the defocusing range remained stable over 12 months (1.8+/-0.4 D). A clinically relevant posterior capsule opacification with a significant decrease of visual acuity (0.4+/-0.2) and a need for Nd: YAG capsulotomy was diagnosed in 12 patients between 15 and 22 (mean 20+/-4, median 20) months postoperatively. All capsulotomies were performed without complication. Six weeks after capsulotomy, best corrected distance visual acuity was improved (1.1+/-0.1), near visual acuity with best distance correction was 0.4+/-0.1 and the accommodative range determined by near point was 1.95+/-0.6 D and by defocusing was 1.88+/-0.47 D. Six weeks after capsulotomy, measurements of the accommodative range did not show any statistical difference to the 12-month results before the occurrence of PCO (P>0.5).

CONCLUSIONS

A clinically relevant PCO with a significant decrease of visual acuity necessitating Nd: YAG capsulotomy occurred mainly after 15 postoperative months in patients with 1CU. Our results indicate that Nd: YAG capsulotomy may not affect the accommodation ability of the 1CU. Nevertheless, long-term studies are needed to further analyze the accommodative properties.

The effect of lens edge design versus anterior capsule overlap on posterior capsule opacification

PURPOSE

To determine whether lens edge design or anterior capsule overlap on the intraocular lens (IOL) has greater effect on posterior capsule opacification (PCO).

DESIGN

Retrospective cohort clinical study.

METHODS

Retrospective.

SETTING

Academic clinical practice.

PATIENT POPULATION

The patient population consisted of 259 uncomplicated surgical patients (259 eyes) with no confounding comorbidity and at least 1 year of follow-up after surgical placement of a silicone or hydrophobic acrylic lens.

OBSERVATION PROCEDURES

Digital retroilluminated photographs were taken to ascertain PCO, anterior capsular opacification (ACO), previous neodymium:YAG capsulotomy and degree of anterior capsule overlap on the IOL optic.

MAIN OUTCOME MEASURES

PCO, ACO, YAG capsulotomy rate, and anterior capsule overlap on the IOL optic.

RESULTS

One hundred forty-eight digital images (74 silicone and 74 acrylic) were measurable for both anterior capsule overlap and PCO. Complete 360 degrees of anterior capsule overlap on the IOL was associated with decreased PCO (P = <.001). A significant negative correlation was found between the degree of anterior capsule overlap and PCO (P = <.001). Evaluation of PCO, and YAG capsulotomy rates were similar between acrylic and silicone lenses. Minimal anterior capsule overlap may also be associated with PCO prevention.

CONCLUSIONS

Implanting a lens with complete anterior capsule overlap on the IOL was found to significantly reduce PCO, which advantage appeared to be greater than PCO prevention by a truncated, sharp edge IOL design.

Effect of intraocular lens optic edge design and material on fibrotic capsule opacification and capsulorhexis contraction

PURPOSE

To examine the influence of intraocular lens (IOL) optic edge design and optic material on fibrosis of the anterior and peripheral posterior capsules and on capsulorhexis contraction.

SETTING

Department of Ophthalmology, Medical University of Vienna, Vienna, Austria.

METHODS

This randomized controlled patient- and examiner-masked study comprised 210 eyes of 105 patients with bilateral age-related cataract. In Group 1 (n = 53), the Sensar OptiEdge AR40e hydrophobic acrylic IOL with a sharp posterior optic edge was compared with the AR40 acrylic IOL with a round edge. In Group 2 (n = 52), the ClariFlex OptiEdge silicone IOL with a sharp posterior optic edge was compared with the PhacoFlex SI-40 silicone IOL with a round edge All IOLs were manufactured by Advanced Medical Optics, Inc. Standardized digital slitlamp images of anterior capsule opacification (ACO) and fibrotic posterior capsule opacification (PCO) were taken 1 year postoperatively, and digital retroillumination images were taken at 1 week and 1 year. The intensity of fibrotic PCO was graded subjectively (score 0 to 4), ACO was graded objectively (score 0% to 100%), and the capsulorhexis area (mm(2)) was determined objectively.

RESULTS

One year after surgery, the mean ACO score was 32% in eyes with the sharp-edged acrylic IOL and 29% in eyes with the round-edged acrylic IOL (P<.05). In the silicone group, the mean was 31% and 26%, respectively (P<.05). The mean fibrotic PCO score was lower in eyes with a sharp-edged acrylic IOL than in eyes with a round-edged acrylic IOL (0.26 and 0.93, respectively; P<.05) and in eyes with a sharp-edged silicone IOL than in eyes with a round-edged silicone IOL (0.24 and 0.82, respectively; P<.001). At 1 year, the mean capsulorhexis area was statistically significantly smaller in eyes with a sharp-edged silicone IOL than in eyes with a round-edged silicone IOL (P<.05).

CONCLUSIONS

Acrylic and silicone IOLs with the sharp OptiEdge design led to significantly less fibrotic PCO but more ACO than round-edged acrylic and silicone IOLs. The sharp-edged silicone IOL caused significantly more capsulorhexis contraction than the round-edged silicone IOL and both acrylic IOLs.

The Auckland Cataract Study: 2 year postoperative assessment of aspects of clinical, visual, corneal topographic and satisfaction outcomes

AIM

To assess clinical, visual, computerised corneal topographic, and subjective satisfaction with visual acuity, in a cohort of subjects 2 years after phacoemulsification surgery in a public hospital in New Zealand.

METHODS

Prospective study of a representative sample of 97 subjects (20%) randomly selected from 480 subjects in the original Auckland Cataract Study (ACS) cohort. The clinical assessment protocol was identical to the ACS and included an extensive questionnaire to enable direct comparisons to be made between the two groups.

RESULTS

The study population was predominantly female (66%) with a mean age of 76.3 (SD 9.9) years. New systemic and ocular disease affected 18.4% and 10.3% of subjects respectively, and 10.3% required referral to either a general practitioner (2.1%) or ophthalmologist (8.2%). Mean best spectacle corrected visual acuity (BSCVA) was 0.2 (0.2) logMAR units (6/9 Snellen equivalent), with mean spherical equivalent -0.37 (1.01) dioptres (D) and astigmatism -1.07 (0.70) D 2 years postoperatively, compared to mean BSCVA 0.1 (0.2) logMAR units (6/7.5 Snellen equivalent), spherical equivalent -0.59 (1.07) D, and astigmatism -1.14 (0.77) D 4 weeks after surgery. 94.9% of subjects retained a BSCVA of 6/12 or better, irrespective of pre-existing ocular disease. The overall posterior capsule opacification (PCO) rate was 20.4% and this was visually insignificant in all but 3.1% of eyes that had already undergone Nd:YAG posterior capsulotomy. Orbscan II elevation technology demonstrated corneal stability 2 years after uncomplicated phacoemulsification. Although corneal astigmatism was eliminated in approximately half of the subjects 1 month postoperatively, astigmatism showed a tendency to regress towards the preoperative level with local corneal thickening at the site of incision 2 years after cataract surgery. Of fellow eyes, 61.2% had undergone cataract surgery. Overall, 75.3% of subjects were moderately to very satisfied with their current level of visual acuity.

CONCLUSION

Two years after cataract surgery subjects are generally satisfied with their current level of vision and distance BSCVA is 6/12 or better in the majority of eyes. Although only a minority of eyes develop sufficient PCO to require capsulotomy 10.3% of eyes develop new vision threatening ocular pathology.

Relationship between anterior capsule contraction and posterior capsule opacification after cataract surgery in patients with diabetes mellitus

PURPOSE

To prospectively assess the relationship between contraction of the anterior capsule opening and posterior capsule opacification (PCO) after cataract surgery in patients with diabetes mellitus.

SETTING

Department of Ophthalmology, University of Tokyo School of Medicine, Tokyo, Kaiya Eye Clinic, Hamamatsu, and Department of Ophthalmology, Institute of Clinical Medicine, University of Tsukuba, Ibaragi, Japan.

METHODS

This study comprised 45 patients (45 eyes) with diabetes mellitus who had cataract surgery. In all eyes, the anterior capsule opening area and degree of PCO were determined by diaphanoscopy using an anterior eye segment analysis system (EAS-100, Nidek, Inc.) 1 day and 1 year postoperatively.

RESULTS

There was no correlation between the size of the anterior capsule opening area 1 day after surgery and the degree of PCO 1 year after surgery (Pearson correlation coefficient [r] = 0.041; P =.79). The percentage reduction in the anterior capsule opening area from 1 day to 1 year after surgery did not correlate with the degree of PCO 1 year after surgery (r = -0.08; P =.60).

CONCLUSION

Contraction of the anterior capsule opening and PCO after cataract surgery cannot be explained by a common mechanism.

Effect of a silicone intraocular lens with a sharp posterior optic edge on posterior capsule opacification

PURPOSE

To compare the inhibiting effect on posterior capsule opacification (PCO) of a silicone intraocular lens (IOL) with a sharp posterior optic edge (ClariFlex OptiEdge, Advanced Medical Optics) and a silicone IOL with a round optic edge (PhacoFlex SI-40, Advanced Medical Optics).

SETTING

Department of Ophthalmology, University of Vienna, Vienna, Austria.

METHODS

This prospective randomized patient- and examiner-masked study comprised 104 eyes of 52 patients with bilateral age-related cataract. All patients had cataract surgery in both eyes and received a sharp-edged IOL in 1 eye and a round-edged IOL in the other eye. Postoperative examinations were at 1 week, 1 and 6 months, and 1 year. Digital slitlamp and retroillumination images were taken of each eye. The amount of PCO was assessed subjectively at the slitlamp and objectively using Automated Quantification of After-Cataract (AQUA) automated-image analysis software.

RESULTS

The sharp-edged IOL group had significantly less regeneratory and fibrotic PCO 1 month, 6 months, and 1 year after surgery. The mean AQUA PCO score (scale 0 to 10) was 0.71 in the sharp-edged IOL group and 1.40 in the round-edged IOL group (P<.001). The sharp-edged IOL group had less peripheral fibrotic PCO. There was no significant difference between the 2 IOL groups in patient reports of edge glare.

CONCLUSION

The sharp-edged design of the ClariFlex OptiEdge silicone IOL led to significantly less PCO than the round-edged PhacoFlex SI-40 IOL 1 year postoperatively.

Neodymium:yttrium-aluminum-garnet capsulotomy and intraocular pressure in pseudophakic patients with glaucoma

OBJECTIVE

To determine the 1- and 3-hour changes in intraocular pressure after neodymium:yttrium-aluminum-garnet (Nd:YAG) capsulotomy in pseudophakic patients with glaucoma and to determine the effect of acetazolamide and apraclonidine on these changes.

DESIGN

Randomized controlled trial.

PARTICIPANTS

Pseudophakic patients with glaucoma requiring Nd:YAG posterior capsulotomy (n = 76).

INTERVENTION

Patients undergoing Nd:YAG posterior capsulotomy were randomly allocated to receive no therapy, oral acetazolamide (250 mg), or topical apraclonidine 1% within 1 hour before capsulotomy.

MAIN OUTCOME MEASURES

Intraocular pressures 1 and 3 hours after laser therapy were recorded.

RESULTS

Data were available for 76 eyes in 76 patients. Twenty-nine patients received no therapy; 24, oral acetazolamide; and 23, apraclonidine. One fifth (6/29) of patients with glaucoma developed a pressure rise of > or =5 mmHg if untreated, and 3% (1/29) developed a pressure rise of >10 mmHg. In comparison, no patients in the acetazolamide group developed a pressure rise of > or =5 mmHg (P = 0.02), and 1 of 24 in the apraclonidine group (P = 0.08) developed such a pressure rise, with none developing a pressure rise of >10 mmHg. When comparing all treated with nontreated, a reduction in the proportion with pressure rise was found (P = 0.01). All of the patients who developed a pressure rise of > or =5 mmHg did so within the first hour.

CONCLUSIONS

In the absence of therapy, clinically significant post-Nd:YAG pressure rises occur in one fifth of patients with glaucoma undergoing capsulotomy. Oral acetazolamide and topical apraclonidine reduce the frequency and magnitude of pressure rises and are of comparable effectiveness. In this study, all clinically important pressure rises developed within the first hour.

Neodymium:YAG laser posterior capsulotomy after implantation of AcrySof intraocular lenses

PURPOSE

To report the incidence of neodymium:YAG (Nd:YAG) laser posterior capsulotomy after phacoemulsification and implantation of AcrySof (Alcon) intraocular lenses (IOLs).

SETTING

Private practice, Wolfe Clinic, Marshalltown, Iowa, USA.

METHODS

A retrospective diagnosis and procedure code review of 12419 consecutive cases having phacoemulsification and AcrySof IOL implantation from January 1995 through December 2002 was performed. The outcome parameter was the incidence of Nd:YAG laser posterior capsulotomies.

RESULTS

An Nd:YAG laser posterior capsulotomy was performed in 763 (6.1%) of the 12419 cases. The incidence of posterior capsulotomy was approximately 1% at 1 year, increasing in linear fashion by approximately 1% to 2% per year.

CONCLUSIONS

The Nd:YAG laser posterior capsulotomy rate after implantation of AcrySof IOLs was relatively low; the cumulative rate was approximately 1% to 2% new cases per year over a 7-year period, with a plateau suggested at year 6.

Posterior capsule opacification after implantation of CeeOn Edge 911A, PhacoFlex SI-40NB, and AcrySof MA60BM lenses

PURPOSE

To perform an intraindividual comparison of posterior capsule opacification (PCO) with 2 foldable intraocular lenses (IOLs) and a foldable acrylic IOL 1 year after in-the-bag implantation.

SETTINGS

Seven German ophthalmology centers.

METHODS

In an open prospective randomized multicenter study, each center intraindividually compared a high-refractive-index, sharp-edged optic silicone IOL (CeeOn Edge 911A, Pharmacia) with a high-refractive-index, round-edged optic silicone IOL (PhacoFlex SI-40NB, Allergan) or a sharp-edged optic acrylic IOL (AcrySof MA60BM, Alcon). Of 288 randomized patients, 247 had standard phacoemulsification with in-the-bag IOL implantation in both eyes by the same surgeon. One eye of each patient received a CeeOn Edge IOL and the fellow eye, an AcrySof or PhacoFlex IOL. A morphologic evaluation of PCO was performed using the Evaluation of Posterior Capsule Opacification (EPCO) system 1 to 2 weeks and 11 to 14 months after surgery. The digital pictures were evaluated by an independent investigator who was blind to the type of IOL. Intraindividual differences in EPCO scores were statistically evaluated by a 1-sided binomial test at an alpha-level of 5%.

RESULTS

One year after surgery, 127 patients with the AcrySof IOL and 102 patients with the PhacoFlex IOL in the control eye were reexamined. Functional results, safety, and handling were not significantly different between the 3 IOLs. All reexamined eyes had a very low PCO grade. The EPCO values revealed less PCO in eyes with the CeeOn Edge IOL than in eyes with the AcrySof or PhacoFlex IOL, but the difference was not statistically significant. A neodymium:YAG laser capsulotomy was performed in 1 eye with a CeeOn Edge IOL, 1 eye with an AcrySof IOL, and 2 eyes with a PhacoFlex IOL.

CONCLUSIONS

The EPCO PCO grade was low 1 year after implantation of CeeOn Edge 911A, PhacoFlex SI-40NB, and AcrySof MA60BM IOLs; there was no statistically significant difference between the IOLs. The impact of IOL material and edge design on PCO development might be relevant in a long-term follow-up of this study.

Anterior capsule relationship of the AcryS of intraocular lens optic and posterior capsule opacification

OBJECTIVE

To evaluate the relationship of the anterior capsule and the AcrySof MA30BA intraocular lens (IOL) and its impact on the development of central posterior capsule opacification (PCO).

DESIGN

Prospective, randomized, controlled trial.

PARTICIPANTS

Two hundred two patients with senile cataracts received an AcrySof IOL between July and December 1998 at Iladevi Cataract and IOL Research Center, Ahmedabad, India.

INTERVENTION

Patients were randomized prospectively to receive 1 of the 3 possibilities of anterior capsule and IOL optic relationship: group 1, total anterior capsule cover (360 degrees ) of the optic; group 2, no anterior capsule cover (360 degrees ) of the optic; group 3, partial anterior capsule cover (<360 degrees ) of the optic. After surgery, slit-lamp video photography was performed every 6 months for 3 years. Analyses of variance and chi-square tests were used to compare treatment groups.

MAIN OUTCOME MEASURES

Incidence of PCO in the 3 groups. The posterior capsule was divided into 3 zones: peripheral, central 3 mm, and midperipheral (the space between the peripheral and the central zones).

RESULTS

The average follow-up was 35.3 +/- 1.52 months in all the groups. At 3 years, the rate of central PCO was 6.4% in group 1, 7.1% in group 2, and 5.9% in group 3 (P = 0.9). Midperipheral PCO was present in 24.2% in group 1, 16% in group 2, and 20.6% in group 3 (P = 0.9). Peripheral PCO was seen in 100% of patients in all groups. The neodynium:yttrium-aluminum-garnet laser (Nd:YAG) posterior capsulotomy rate was 0% in all groups.

CONCLUSIONS

There was no significant difference in the incidence of development of central PCO among the 3 groups. No patient experienced central PCO that required Nd:YAG capsulotomy. When using the AcrySof IOL model MA30BA, the relationship of the anterior capsule and the IOL does not seem to be a factor that relates to the development of central PCO.

Bendazac Lysine Inhibition of Human Lens Epithelial Cell Adhesion to Polymethylmethacrylate Intraocular Lenses

The aim of the present work was to evaluate the effect of bendazac lysine on the human lens epithelial cell line HLE-B3 adhesion to polymethylmethacrylate (PMMA) intraocular lenses (IOLs). After adherence to IOLs, cells were incubated in the presence of the drug for 24 h. The number of cells contained in a 6-mm(2) area was then counted with an inverted phase microscope and adherent cells were distinguished from detached floating cells by focusing through the medium. Results obtained show that bendazac is able to induce a linear dose-dependent inhibition of HLE-B3 adhesiveness to PMMA IOLs. In particular, treatment with bendazac 33, 100 and 300 microM resulted in a 15, 32 and 54% inhibition, respectively. Statistical analysis shows that this effect is significant at 100 microM (p < 0.05) and 300 microM (p < 0.01). The analysis of the effects of bendazac on the viability and on the proliferative capacity of HLE-B3 cells did not show any drug-related toxicity up to the concentration of 400 microM. The present study demonstrates that bendazac lysine is able to inhibit adhesion of lens epithelial cells to PMMA IOLs and suggests the potential beneficial use of this drug in preventing secondary cataract development.

Induction of apoptosis by the calcium antagonist mibefradil correlates with depolarization of the membrane potential and decreased integrin expression in human lens epithelial cells

BACKGROUND

Posterior capsule opacification is still the major complication in cataract surgery and is caused by migration and proliferation of residual lens epithelial cells. The challenge of a suitable therapy to inhibit capsule opacification is to specifically interfere with cellular mechanisms. Our approach using the T-calcium channel antagonist mibefradil is based on the hypothesis that this drug inhibits the signaling pathways mediated by cell adhesion.

METHODS

The influence of mibefradil dihydrochloride was investigated on primary human lens epithelial cells (hLEC) from cataract surgery and on the human lens cell line HLE-B3. Apoptosis was quantitatively analyzed by flow cytometry (% increase of the sub-G1 peak), and verified by confocal microscopy (annexin V-biotin, TUNEL reaction). The membrane potential was detected by a membrane potential-sensitive dye. Integrin expression and proliferation were measured by flow cytometry. T-calcium channels in hLEC were verified by the whole-cell configuration of the patch-clamp technique.

RESULTS

Mibefradil induced apoptosis in hLEC. Early signs of apoptosis were observed after only 4 h of incubation with mibefradil, accompanied by a significantly reduced cell area. Apoptosis correlated with inhibited integrin expression, reduced proliferation and the depolarization of the membrane potential. We could identify calcium channels of the T-type in our primary hLEC.

CONCLUSIONS

We suggest that depolarization of the membrane potential and the inhibition of integrin expression leads to the loss of cell adhesion, which is the reason for the induction of apoptosis. Thus, mibefradil seems to be a suitable drug to prevent cell adhesion, migration and proliferation.

Effect of 1-piece and 3-piece AcrySof intraocular lenses on the development of posterior capsule opacification after cataract surgery

PURPOSE

To evaluate the effect of 1-piece and 3-piece hydrophobic acrylic intraocular lenses (IOLs) on posterior capsule opacification (PCO) after cataract surgery.

SETTING

Ophthalmology departments of 3 hospitals in the United Kingdom and Germany and the Department of Physics at a United Kingdom university.

METHODS

A series of 131 patients having cataract surgery had implantation of an acrylic 1-piece (SA30AL) or an acrylic 3-piece (MA30BA) IOL (AcrySof, Alcon). Surgery was performed according to standardized protocol by a single surgeon at each hospital. Posterior capsule opacification was assessed using digital retroillumination photography. All images were analyzed at a single center according to a standard protocol. Data were analyzed 6 months and 1 year after surgery.

RESULTS

There was no statistically significant difference in the percentage area of PCO between the 1-piece (mean 16.0% +/- 15.7% [SD]) and 3-piece (mean 13.6% +/- 19.8%) cohorts 6 months and 1 year after surgery (P =.0664).

CONCLUSION

There was no evidence of a difference in the area of PCO after cataract surgery between 1-piece and 3-piece IOLs, which were otherwise matched for material and lens geometry.

Cumulative probability of neodymium: YAG laser posterior capsulotomy after phacoemulsification

PURPOSE

To retrospectively analyze the cumulative probability of neodymium:YAG (Nd:YAG) laser posterior capsulotomy after phacoemulsification and to evaluate the risk factors.

SETTING

Ando Eye Clinic, Kanagawa, Japan.

METHODS

In 3997 eyes that had phacoemulsification with an intact continuous curvilinear capsulorhexis, the cumulative probability of posterior capsulotomy was computed by Kaplan-Meier survival analysis and risk factors were analyzed using the Cox proportional hazards regression model. The variables tested were sex; age; type of cataract; preoperative best corrected visual acuity (BCVA); presence of diabetes mellitus, diabetic retinopathy, or retinitis pigmentosa; type of intraocular lens (IOL); and the year the operation was performed. The IOLs were categorized as 3-piece poly(methyl methacrylate) (PMMA), 1-piece PMMA, 3-piece silicone, and acrylic foldable.

RESULTS

The cumulative probability of capsulotomy after cataract surgery was 1.95%, 18.50%, and 32.70% at 1, 3, and 5 years, respectively. Positive risk factors included a better preoperative BCVA (P =.0005; risk ratio [RR], 1.7; 95% confidence interval [CI], 1.3-2.5) and the presence of retinitis pigmentosa (P<.0001; RR, 6.6; 95% CI, 3.7-11.6). Women had a significantly greater probability of Nd:YAG laser posterior capsulotomy (P =.016; RR, 1.4; 95% CI, 1.1-1.8). The type of IOL was significantly related to the probability of Nd:YAG laser capsulotomy, with the foldable acrylic IOL having a significantly lower probability of capsulotomy. The 1-piece PMMA IOL had a significantly higher risk than 3-piece PMMA and 3-piece silicone IOLs.

CONCLUSIONS

The probability of Nd:YAG laser capsulotomy was higher in women, in eyes with a better preoperative BCVA, and in patients with retinitis pigmentosa. The foldable acrylic IOL had a significantly lower probability of capsulotomy.

Retinal breaks and detachment after neodymium:YAG laser posterior capsulotomy

PURPOSE

To determine the 5-year incidence of retinal breaks and retinal detachment (RD) after neodymium:YAG (Nd:YAG) laser posterior capsulotomy and the prophylactic treatment of perioperative retinal breaks.

SETTING

Department of Ophthalmology, Helsinki University Central Hospital, Helsinki, Finland.

METHODS

This study design was stage 2 of a prospective nonrandomized interventional case series. Of 341 patients (350 eyes) referred for a first Nd:YAG laser posterior capsulotomy between October 1994 and February 1996, 211 (220 eyes) were examined for retinal breaks before and after capsulotomy (stage 1 of study). Asymptomatic breaks were prophylactically photocoagulated. Of the 211 patients, 106 (113 eyes) were examined at stage 2 a median of 4.9 years after Nd:YAG capsulotomy. The charts of all 341 patients were reviewed for development of RD and retinal breaks. The proportion of patients developing RD was estimated by Kaplan-Meier survival analysis, and the risk for RD was modeled by Cox proportional hazard regression.

RESULTS

By 5 years, the overall cumulative proportion of RD in the 341 patients was 2.0% (95% confidence interval [CI], 1.0-4.0). Of the 211 eyes enrolled in stage 1, 2 (1.2%) developed an RD (95% CI, 0.3-4.7). Of 51 fellow eyes that had a capsulotomy and 120 eyes that had a capsulotomy but were not enrolled in stage 1 and were not prophylactically treated, RD occurred in 6 eyes (5.8%; 95% CI, 2.6-13). By univariate Cox regression, the axial length, whether modeled as a continuous variable (hazard ratio [HR] 1.51 for each millimeter increase) or categorized using 25.0 mm as a cutoff (HR 11.1), had the strongest association with RD after Nd:YAG posterior capsulotomy (P =.0002 and P =.0016, respectively).

CONCLUSIONS

In addition to the capsulotomy, other known risk factors predicted RD after Nd:YAG laser posterior capsulotomy. Close follow-up and prophylactic photocoagulation of preexisting retinal breaks are worth considering, especially in high-risk eyes.

Cost-utility analysis of cataract surgery in the second eye

OBJECTIVE

To perform a reference case cost-utility analysis of second-eye cataract surgery by using the current literature on cataract outcomes and complications.

DESIGN

Computer-based econometric modeling.

METHODS

Visual acuity data of patients treated and observed over a 4-month postoperative period were obtained from the U.S. National Cataract Patient Outcomes Research Team report. The results from this prospective study were combined with those of other studies that investigated the complication rates of cataract surgery to complete the cohort of patients and outcomes. These synthesized data were incorporated with time trade-off utility values, which accounted for prior successful cataract surgery in the fellow eye. Cost-utility determinations were made with decision analysis, and present value modeling was used to account for the time value of money and health state consequences.

MAIN OUTCOME MEASURES

The number of quality-adjusted life-years (QALYs) gained was calculated for the study group undergoing second-eye cataract surgery, assuming that the postoperative vision in the second eye was equivalent to the vision in the first eye after surgery (20/27). This was divided into the cost of the procedure to find the number of year 2001 nominal U.S. dollars spent per QALY gained.

RESULTS

Second-eye cataract surgery, as compared with unilateral pseudophakia, resulted in a mean gain of 1.31 undiscounted QALYs per patient treated. A 3% annual discount rate, dependent on the duration of benefit, was used, yielding 0.92 discounted QALYs gained over a 12-year life expectancy. The mean discounted cost of treatment for each patient totaled 2509 US dollars. The cost divided by the QALYs gained (benefit) resulted in 2727 US dollars per QALY gained for this procedure. Sensitivity analysis varying costs and utility values revealed a range from 2045 US dollars to 3649 US dollars per QALY gained.

CONCLUSIONS

Second-eye cataract surgery is an extremely cost-effective procedure when compared with other interventions across medical specialties. The cost-effectiveness of second-eye surgery diminishes only slightly from the 2023 US dollars per QALY gained from first-eye cataract surgery. This suggests that patients with good vision in one eye and visual loss from cataract in the fellow eye derive substantial benefit from cataract extraction.

Use of Nd:YAG laser capsulotomy

Surgery for cataract removal has become successively refined such that posterior capsular opacification is the most common problem presenting after modern cataract extraction. Various techniques and treatments exist to manage patients with posterior capsular opacification using Nd:YAG capsulotomy. There are many possible variations in initial assessment, pre-laser treatments, laser techniques, and follow-up routines. The literature on the use of Nd:YAG laser for capsulotomy was reviewed and interpreted. This article presents the currently available knowledge in a format that allows the practitioner to tailor an evidence-based protocol for treating patients with symptomatic posterior capsule opacification.

Lens epithelial cell migration between posterior capsule and intraocular lens with variously finished posterior optic edge and two haptic angulations

PURPOSE

To compare lens epithelial cell migration between intraocular lens (IOL) optics and the posterior capsule of IOLs with various edges and haptic angulations.

METHODS

Experimental acrylic IOLs with 3 types of finishing (none, polishing, tumbling and polishing) and 2 types of haptic angulation (10 and 15 degrees ) as well as 3 (AcrySof MA30BA, Sensar AR40, CeeOn 911) clinically implanted IOLs were inserted in rabbit eyes. Scanning electron-microscopic examination of IOLs was carried out before surgery and histological examination of lens capsules 3 weeks after surgery. The grading of lens epithelial cell migration under the IOL was made by scoring.

RESULTS

Scanning electron-microscopic examination showed that the optic edge sharpness decreased according to the finishing in experimental IOLs. The AcrySof and CeeOn lenses had sharp edges and the Sensar had a rounded edge. The migration score was highest in the IOL with a rounded edge whereas it was lowest in IOLs with a sharp edge and large haptic angulation. There was no significant difference between the scores of clinically implanted IOLs.

CONCLUSION

Sharpness of the optic edge may be a critical factor for the prevention of posterior capsule opacification and more important than haptic angulation in acrylic IOLs.

Posterior capsule opacification: silicone plate-haptic versus AcrySof intraocular lenses

PURPOSE

To evaluate posterior capsule opacification (PCO) in fellow eyes, 1 receiving a silicone intraocular lens (IOL) and the other, an acrylate IOL.

SETTING

Department of Ophthalmology, Isala Clinics, Zwolle, The Netherlands.

METHODS

This retrospective study comprised 107 patients (214 eyes). In each patient, 1 eye was randomly selected to have implantation of an acrylate IOL (AcrySof MA30BA or MA60BM, Alcon) and the other eye, a plate-haptic silicone IOL (AA4203VF, Staar). Outcome measures were the total PCO index, percentage of neodymium:YAG (Nd:YAG) capsulotomies performed, and logMAR best corrected visual acuity (BCVA). The follow-up was 3 years.

RESULTS

The total PCO index was significantly lower in the AcrySof group than in the plate-haptic silicone group (P<.0001). There was no significant difference in logMAR BCVA between groups (P>.05). The percentage of Nd:YAG laser treatments was significantly lower in the AcrySof group (2.8%) than in the plate-haptic silicone group (23.1%) (P<.05).

CONCLUSIONS

There was significantly less PCO and a lower Nd:YAG laser capsulotomy rate after AcrySof IOL implantation than after plate-haptic silicone IOL implantation. These results did not seem to affect the logMAR BCVA as there were no significant differences between groups in this parameter.

Posterior capsule opacification after phacoemulsification: silicone CeeOn Edge versus acrylate AcrySof intraocular lens

PURPOSE

To compare the rates and morphologic features of posterior capsule opacification (PCO) after small-incision phacoemulsification and in-the-bag implantation of 2 foldable intraocular lenses (IOLs) over an 18-month follow-up.

SETTING

Departments of Ophthalmology, Hospital of Conegliano, Conegliano, and Maggiore Hospital of Bologna, Bologna, Italy.

METHODS

In an open clinical study, 78 cataract patients were randomly selected to have implantation of a silicone CeeOn Edge (Pharmacia) or acrylate AcrySof (Alcon) IOL after phacoemulsification cataract surgery. All the patients were operated on using a standard technique and in-the-bag IOL implantation. One eye in each patient was studied. Morphologic evaluation of PCO was performed using Evaluation of Posterior Capsule Opacification software.

RESULTS

At 18 months in the CeeOn Edge group, 36 eyes (90%) had a clear posterior capsule and 4 (10%) had PCO that did not affect visual acuity. In the AcrySof group, 26 eyes (68%) had a clear posterior capsule, 11 (29%) had PCO that did not affect visual acuity, and 1 (3%) had PCO with a decrease of 2 or more lines of visual acuity that required a neodymium:YAG laser capsulotomy. No eye developed Elschnig pearls or stretched folds in the bag. The postoperative best corrected visual acuity ranged from 0.8 to 1.0 in 96% in the CeeOn Edge group and in 92% in the AcrySof group. No IOL haze or discoloration was observed in the CeeOn Edge group. Mild IOL decentration and tilting occurred in 4 AcrySof eyes; however, no glistenings were found any AcrySof IOL.

CONCLUSIONS

Both the CeeOn Edge and AcrySof groups had a low incidence of PCO after an 18-month follow-up. The CeeOn Edge group had significantly less PCO than the AcrySof group. These results confirm that IOLs with square truncated edges create a barrier effect at the optic edge, reducing the overall incidence of PCO.

Posterior capsule opacification: comparison of 3 intraocular lenses of different materials and design

PURPOSE

To compare posterior capsule opacification (PCO) after cataract surgery with implantation of 3 intraocular lenses (IOLs) of different materials and design.

SETTING

St. Erik's Eye Hospital, Stockholm, Sweden.

METHODS

In this prospective clinical study, 180 patients had standardized phacoemulsification performed by a single surgeon and were randomized to have implantation of a heparin-surface-modified (HSM) poly(methyl methacrylate) (PMMA) IOL (809C, Pharmacia & Upjohn), a silicone IOL (SI-40NB, Allergan), or an acrylic IOL (AcrySof MA60BM, Alcon). To morphologically evaluate PCO, retroillumination photographs were obtained and analyzed using Evaluation of Posterior Capsule Opacification computer software. The neodymium:YAG (Nd:YAG) capsulotomy rate was recorded.

RESULTS

After 2 years, the HSM PMMA IOL group had significantly more PCO than the silicone and AcrySof IOL groups; the silicone group had significantly more PCO than the AcrySof group (P<.05). The Nd:YAG capsulotomy rate was 20% in the HSM PMMA group, 22% in the silicone group, and 8% in the AcrySof group.

CONCLUSION

Patients with an AcrySof IOL developed significantly less PCO than those with a silicone or HSM PMMA IOL with a round-edged design.

A comparison of Nd:YAG capsulotomy rate in two different intraocular lenses: AcrySof and Stabibag

PURPOSE

To evaluate the incidence of posterior capsule opacification after implantation of two different intraocular lenses (IOLs), AcrySof and Stabibag, by comparing the neodymium:YAG (Nd:YAG) laser capsulotomy rates.

METHODS

The medical records of 596 patients (705 eyes) who underwent phacoemulsification and posterior chamber IOL implantation using either AcrySof (n = 335) or Stabibag (n = 370) IOLs during a 1-year (1999) period were reviewed. Eyes with secondary cataract, combined procedures or operative complications, such as capsule tears, were excluded from the study. The subjects' age, sex, surgeon (two surgeons), and time for Nd:YAG laser capsulotomy were recorded.

RESULTS

The mean follow-up was 23 months in both IOL groups. There were no statistically significant differences within the two IOL groups regarding sex distribution or surgeon. The mean age in the AcrySof group was 77.0 years compared to 79.2 years in the Stabibag group (p = 0.001). Nd:YAG laser capsulotomy was performed in 7.6% of patients in the Stabibag group compared to 2.7% in the AcrySof group (i.e. at a significantly higher rate) (p = 0.004). Survival analyses demonstrated that age and type of IOL were the only independent predictors of the incidence of capsulotomy.

CONCLUSIONS

This study shows that the frequency of eyes with posterior capsule opacification needing capsulotomy was significantly higher in eyes with Stabibag IOLs compared to eyes with AcrySof IOLs.

Cataract surgery results after pars plana vitrectomy

Continuous refinements in vitreoretinal surgical techniques and an increasing number of posterior segment disorders are being successfully managed with pars plana vitrectomy (PPV). This has resulted in an increase in the number of vitrectomized eyes seen by cataract surgeons. Cataract surgery in previously vitrectomized eyes has been reported to be more challenging than in eyes without previous vitrectomy. Special considerations and precautions are often required before, during, and after the surgery to successfully address these challenges. Several studies have reported that phacoemulsification with intraocular lens implantation after PPV is a relatively safe procedure that can improve visual acuity and quality of life. The extent of visual improvement may be limited only by retinal comorbidity.

Quantification of posterior capsule opacification with round and sharp edge intraocular lenses

PURPOSE

To quantitatively evaluate and compare intraocular lenses (IOLs) with a round or sharp optic edge design for posterior capsule opacification (PCO).

STUDY DESIGN

Prospective comparative observational case series. PARTICIPANTS/MATERIALS: Photographs from 174 eyes were analyzed for PCO at the Department of Ophthalmology, Ruprecht-Karls-University of Heidelberg, Heidelberg, Germany.

MAIN OUTCOME MEASURES

Part I: 121 eyes of 121 patients were analyzed for quantification of PCO. IOLs evaluated were Corneal ACR6 (n = 21), Alcon Acrysof (n = 20), Allergan AR40 (n = 27), Pharmacia 811 one-piece polymethyl methacrylate (PMMA) IOL (n = 24), and Pharmacia 911A silicone IOL (n = 29). Mean follow-up was 14.01 +/- 2.81 months; mean patient age was 73.2 +/- 7.3 years. The morphologic PCO formation was evaluated for the entire optic and in the central 3-mm zone. Part II: In 53 eyes of 46 patients aged 73.4 +/- 10.8 years with an Alcon Acrysof IOL, PCO formation and capsulorrhexis/optic overlapping were analyzed 34.2 +/- 4 months after cataract surgery using EPCO Software.

RESULTS

Part I: The PCO values of the entire optic were for Corneal ACR6, 1.93 +/- 0.62; PMMA, 0.64 +/- 0.63; AR40, 0.55 +/- 0.28; Alcon Acrysof, 0.145 +/- 0.27; and 0.161 +/- 0.181 for the Pharmacia 911A IOL (P < 0.01). The PCO values of the central 3-mm zone were for Corneal ACR6, 1.64 +/- 0.96; PMMA, 0.49 +/- 0.39; AR40, 0.22 +/- 0.32; Alcon Acrysof, 0.08 +/- 0.21; and 0.06 +/- 0.11 for the Pharmacia 911A IOL (P < 0.01). Part II: Average overlapping of capsulorrhexis and Acrysof IOL optic was 40.5% +/- 12.4%. There was a significant correlation between PCO values and overlapping (r = -0.69, P < 0.001).

CONCLUSIONS

The sharp-edge IOL types (Alcon Acrysof and Pharmacia 911A silicone IOL) resulted in statistically significantly lower PCO values for analysis of the entire optic area and central 3-mm zone. There was no statistically significant difference in PCO values between the two sharp-edge optic IOLs. An overlapping of capsulorrhexis rim and the anterior IOL optic surface of more than 20% resulted in significantly lower PCO values with the Acrysof IOL.

Lens epithelial cells express CD95 and CD95 ligand treatment induces cell death and DNA fragmentation in vitro

PURPOSE

Despite advances in intraocular lens design and material, posterior capsule opacification remains one of the major problems in modern cataract surgery. Therefore, the use of antiproliferative agents has been advocated. CD95 ligand (CD95L, Fas, Apo-1) is a death ligand that triggers apoptosis in susceptible target cells. Apoptosis allows for the safe disposal of cells without damaging the surrounding tissue. The goal of this study was to characterize and evaluate CD95L-induced cell death in cultured lens epithelial cells (LEC).

METHODS

Expression of CD95 in untreated porcine LEC was investigated by flow cytometry. Cell death after CD95L or CD95 agonistic antibody treatment was assessed by crystal violet assay and DNA fragmentation was measured by comet assay.

RESULTS

The presence of CD95 was observed in LEC. CD95L treatment resulted in a time--and concentration-dependent killing of LEC, which was synergistically enhanced by the addition of cyclohexamide. CD95L treatment induced DNA fragmentation.

CONCLUSIONS

The present study confirms the use of apoptosis-inducing CD95L in the inhibition of LEC proliferation. Further studies are needed before clinical application of CD95L to inhibit posterior capsule opacification will be feasible.

Prevention of posterior capsule opacification using capsular tension ring for zonular defects in cataract surgery

PURPOSE

To evaluate the incidence of secondary cataract in phacoemulsification and intraocular lens implantation using a capsular tension ring in case of zonular dehiscence.

METHODS

Phacoemulsification using a double capsular tension ring and intraocular lens implantation was done in 65 eyes with cataract and severe zonular weakness. One year after surgery capsular opacities and fibrosis were detected in a double-blind examination. The results were compared with a control group of 36 eyes that did not have a capsular tension ring but had similar surgery.

RESULTS

In the group with the capsular tension ring and implantation 7.7% of patients had moderate or severe posterior capsule opacification, compared with 36.1% in the control group.

CONCLUSIONS

Capsular tension rings may influence the formation of capsule opacification.