Posterior capsule opacification after phacoemulsification in patients with diabetes mellitus

Type 1 and type 2 diabetes predisposed to higher Nd:YAG capsulotomy rates following cataract surgery: analysis of 53,471 consecutive cases

OBJECTIVE

To assess the effect of diabetes type on Nd:YAG capsulotomy rates following cataract surgery.

DESIGN

A retrospective cohort study.

METHODS

All patients who underwent cataract extraction at the Department of Ophthalmology, Bristol Eye Hospital, Bristol, UK, between 2003 and 2017 were included. The Nd:YAG capsulotomy rate following cataract surgery was assessed and compared between nondiabetic, type 1 diabetes (T1D), and type 2 diabetes (T2D) patients. Multivariate Cox regression analysis controlling for age and sex was used to estimate hazard ratios for Nd:YAG laser capsulotomies.

RESULTS

Included were 53,471 consecutive cataract surgeries. Overall, 42,651 eyes (79.8%) were in nondiabetic patients, 823 eyes (1.5%) were in T1D patients, and 9,997 eyes (18.7%) were in T2D patients. The mean follow-up time was 6.8 ± 4.2 years. In univariate analysis, the eyes of T1D patients (p < 0.001) and T2D patients (p = 0.003) had significantly higher Nd:YAG laser capsulotomy rates than the eyes of nondiabetic patients. In Cox regression analysis adjusted for the patient's age and sex, DM1 (HR 1.692, 95%CI 1.390-2.059, P<0.001) and DM2 (HR 1.157, 95%CI 1.075-1.244, P<0.001) remained significantly predictive for higher Nd:YAG laser capsulotomy rates.

CONCLUSION

In our large cohort study, patients with T1D and T2D were predisposed to high risk for Nd:YAG capsulotomy following cataract surgery. This study may be beneficial and raise awareness regarding the assessment of posterior capsular opacification development in pseudophakic diabetic patients, particularly those with T1D. The significance of ophthalmology screening for diabetes individuals is further supported by this issue.

Neovascular glaucoma following Nd:YAG laser capsulotomy: a rare complication in a postvitrectomised patient with diabetes

To describe a case of acute-onset neovascular glaucoma (NVG) after a neodymium:yttrium-aluminium-garnet (Nd:YAG) capsulotomy in a diabetic vitrectomized eye of a patient with severe systemic and ocular comorbidities. A man in his 50s underwent a Nd:YAG capsulotomy for visually significant posterior capsular opacification with a previous history of vitrectomy with silicone oil in situ for diabetic retinopathy. He had systemic and ocular comorbidities implicating an advanced ischaemic status, both systemically and locally. Five days post Nd:YAG capsulotomy, extensive neovascularisation of the iris and angles was noted. Despite maximum antiglaucoma medication, an evisceration ensued due to intractable NVG. This case report highlights the importance of irreversible complications after a seemingly simple capsulotomy in eyes with advanced ocular conditions and systemic comorbidities necessitating extreme caution.

Cataract Surgery Considerations for Diabetic Patients

PURPOSE OF REVIEW

Given the epidemiology and demographic trends of diabetes mellitus and cataracts, ophthalmologists are likely to encounter patients with both comorbidities at an increasing frequency. Patients with diabetes represent a higher risk population than healthy patients for cataract surgery. In this review, we discuss key risks and risk-mitigation practices when performing cataract surgery on these patients.

RECENT FINDINGS

Patients with diabetes continue to represent a high-risk surgical population: Nagar et al. suggest a dose-dependent relationship may exist between number of intravitreal injections and likelihood of posterior capsular rupture. However, novel treatments are improving outcomes for patients with diabetes. Several studies have reported intracameral phenylephrine/ketorolac may reduce the incidence of post-operative cystoid macular edema while others have discussed the efficacy of pre-treatment and post-treatment with intravitreal bevacizumab on improving cataract surgery outcomes in patients with diabetic retinopathy. Pre-operatively, ophthalmologists should perform an enhanced evaluation, consider timing and lens selection decisions, and complete any appropriate pre-operative treatment. Peri-operatively, surgeons should be aware of pupillary dilation adjustments, combination surgery options, and potential complications. Post-operatively, clinicians should address pseudophakic cystoid macular edema, diabetic macular edema, diabetic retinopathy, and posterior capsular opacification.

The Protective Effect of Metformin Use on Early Nd:YAG Laser Capsulotomy

Purpose

To determine the effect of metformin on early Nd:YAG laser treatment for posterior capsule opacification (PCO) and to explore a molecular mechanism to explain a possible protective effect of metformin against PCO.

Methods

We conducted: 1) a retrospective cohort study of patient eyes undergoing phacoemulsification at our institution; and 2) laboratory investigation of the effect of metformin on the behavior of lens epithelial cells in the context of an animal model for PCO. Population-averaged Cox proportional hazards modeling was used to estimate risk for time to Nd:YAG. For laboratory studies, expression of markers for epithelial-to-mesenchymal transition (EMT) implicated in PCO pathogenesis was measured in tissue culture and following extracapsular lens extraction in a mouse model.

Results

The rate of Nd:YAG laser capsulotomy was 13.1% among the 9798 eyes. Both metformin use and diabetes were protective factors for Nd:YAG laser capsulotomy in univariate analysis. However, in multivariable analysis with nondiabetics as the reference group, only metformin use among diabetics was significantly protective of Nd:YAG (hazard ratio: 0.68, 95% CI: 0.54–0.85, P = 0.0008), while eyes of patients with diabetes without metformin use did not significantly differ (P = 0.5026). Treatment of lens epithelial cells with metformin reduced the level of the EMT markers ⍺-SMA and pERK induced by TGF-β2. Similarly, metformin treatment reduced ⍺-SMA expression in lens epithelial cells following extracapsular lens extraction in a mouse model.

Conclusions

The protective effect of metformin against early Nd:YAG may relate to its ability to downregulate EMT in residual lens epithelial cells that otherwise trend toward myofibroblast development and PCO.

Advanced glycation end products in human diabetic lens capsules

Advanced glycation end products (AGEs) accumulate with age in human lens capsules. AGEs in lens capsules potentiate the transforming growth factor beta-2-mediated mesenchymal transition of lens epithelial cells, which suggests that they play a role in posterior capsule opacification after cataract surgery. We measured AGEs by liquid chromatography-mass spectrometry in capsulorhexis specimens obtained during cataract surgery from nondiabetic and diabetic patients with and without established retinopathy. Our data showed that the levels of most AGEs (12 out of 13 measured) were unaltered in diabetic patients and diabetic patients with retinopathy compared to nondiabetic patients. There was one exception: glucosepane, which was significantly higher in diabetic patients, both with (6.85 pmol/μmol OH-proline) and without retinopathy (8.32 pmol/μmol OH-proline), than in nondiabetic patients (4.01 pmol/μmol OH-proline). Our study provides an explanation for the similar incidence of posterior capsule opacification between nondiabetic and diabetic cataract patients observed in several studies.

Posterior Capsule Opacification: A Review of Experimental Studies

Posterior capsule opacification (PCO) is the most common complication of cataract surgery. It causes a gradual deterioration of visual acuity, which would otherwise improve after a successful procedure. Despite recent advances in ophthalmology, this complication has not been eradicated, and the incidence of PCO can be as high as 10%. This article reviews the literature concerning the pathomechanism of PCO and examines the biochemical pathways involved in its formation and methods to prevent this complication. We also review the reported tests performed in cell cultures under laboratory conditions and in experimental animal models and in ex vivo human lens capsules. Finally, we describe research involving human eyes in the clinical setting and pharmacological methods that may reduce the frequency of PCO. Due to the multifactorial etiology of PCO, in vitro studies make it possible to assess the factors contributing to its complications and search for new therapeutic targets. Not all pathways involved in cell proliferation, migration, and contraction of the lens capsule are reproducible in laboratory conditions; moreover, PCO in humans and laboratory animals may be additionally stimulated by various degrees of postoperative reactions depending on the course of surgery. Therefore, further studies are necessary.

Diabetic retinopathy and diabetic macular oedema pathways and management: UK Consensus Working Group

The management of diabetic retinopathy (DR) has evolved considerably over the past decade, with the availability of new technologies (diagnostic and therapeutic). As such, the existing Royal College of Ophthalmologists DR Guidelines (2013) are outdated, and to the best of our knowledge are not under revision at present. Furthermore, there are no other UK guidelines covering all available treatments, and there seems to be significant variation around the UK in the management of diabetic macular oedema (DMO). This manuscript provides a summary of reviews the pathogenesis of DR and DMO, including role of vascular endothelial growth factor (VEGF) and non-VEGF cytokines, clinical grading/classification of DMO vis a vis current terminology (of centre-involving [CI-DMO], or non-centre involving [nCI-DMO], systemic risks and their management). The excellent UK DR Screening (DRS) service has continued to evolve and remains world-leading. However, challenges remain, as there are significant variations in equipment used, and reproducible standards of DMO screening nationally. The interphase between DRS and the hospital eye service can only be strengthened with further improvements. The role of modern technology including optical coherence tomography (OCT) and wide-field imaging, and working practices including virtual clinics and their potential in increasing clinic capacity and improving patient experiences and outcomes are discussed. Similarly, potential roles of home monitoring in diabetic eyes in the future are explored. The role of pharmacological (intravitreal injections [IVT] of anti-VEGFs and steroids) and laser therapies are summarised. Generally, IVT anti-VEGF are offered as first line pharmacologic therapy. As requirements of diabetic patients in particular patient groups may vary, including pregnant women, children, and persons with learning difficulties, it is important that DR management is personalised in such particular patient groups. First choice therapy needs to be individualised in these cases and may be intravitreal steroids rather than the standard choice of anti-VEGF agents. Some of these, but not all, are discussed in this document.

Reduced NGF Level Promotes Epithelial-Mesenchymal Transition in Human Lens Epithelial Cells Exposed to High Dexamethasone Concentrations

Purpose: To investigate the protective effects of nerve growth factor (NGF) against steroid-induced cataract formation in dexamethasone (Dex)-treated human lens epithelial B-3 (HLE-B3) cells and the possible molecular mechanisms underlying this protection.Materials and Methods: HLE-B3 cells were treated with Dex, and cell viability was assessed using the Cell Counting Kit-8 (CCK-8) assay. The levels of expression of NGF, fibronectin, α-smooth muscle actin (α-SMA), and E-cadherin mRNAs were measured by real-time quantitative polymerase chain reaction (qPCR), and the levels of NGF, fibronectin, α-SMA, E-cadherin, tropomyosin receptor kinase A (TrkA), and Akt proteins were measured by Western blot analysis. Gene expression profiles of growth factors in Dex-treated HLE-B3 cells were determined by PCR arrays. In addition, anterior capsule tissue was obtained during cataract surgery, and the specimens were also examined expressions of NGF.Results: NGF was expressed in HLE-B3 cells and also in lens epithelial cells of anterior lens capsules. Dex treatment of HLE-B3 cells increased their expression of epithelial-mesenchymal transition (EMT) markers and migration activity, while markedly downregulating the expression of NGF. NGF treatment significantly reduced the expression of α-SMA and fibronectin, as well as cell proliferation. The decreased phosphorylation of p38 MAPK and Akt induced by Dex treatment was significantly reversed by treatment with NGF.Conclusion: NGF/TrkA may repress EMT by targeting the p38 MAPK and pAkt pathways in Dex-treated HLE-B3 cells. NGF may be a novel therapeutic target for patients with steroid-induced cataract.

Cataract in diabetes mellitus

Diabetes mellitus (DM) is a chronic systemic disease that has increases in prevalence over time. DM can affect all ocular structures, with cataract being the most common ocular complication. Cataract is the leading cause of blindness worldwide. Due to several mechanisms, there is an increased incidence of cataract formation in the diabetic population. Advancements in technology have now made cataract surgery a common and safe procedure. However, the diabetic population is still at risk of vision-threatening complications, such as diabetic macular edema (ME), postoperative ME, diabetic retinopathy progression, and posterior capsular opacification.

The protective effect of beta-casomorphin-7 via promoting Foxo1 activity and nuclear translocation in human lens epithelial cells

PURPOSE

To investigate the protective effect of beta-casomorphin-7 (β-CM-7) in oxidative stressed human lens epithelial cells (HLECs) and to explore the possible mechanism for oxidative stress in HLECs induced by high glucose.

METHODS

We used HLECs to determine the effect of different concentrations of β-CM-7 on cell viability by 3-(4, 5-dimethyl-2-thiazolyl)-2, 5-diphenyl-2-H-tetrazolimol/L bromide (MTT) assay. We used flow cytometry to determine the content of reactive oxygen species (ROS) induced by oxidative stress and a bioassay kit to determine the oxidant malondialdehyde (MDA) and antioxidant enzyme superoxide dismutase (SOD) levels. We used Western blotting and an immunofluorescence assay to determine the expression of Forkhead box o1 (Foxo1), SP1, and the related protein glutathione peroxidase (GSH-px) at the molecular biology level as well as their intracellular localization.

RESULTS

The expression of Foxo1 and SP1 was weakly expressed when the glucose concentration was 40 mM/L, but was highly expressed when cells were pre-treated with an appropriate concentration of β-CM-7. After pre-treatment with β-CM-7, the cells treated with 40 mM/L glucose for 48 h showed Foxo1 was transferred to the nucleus, and the expression of SP1 was increased. The content of ROS and MDA in the HLECs that were pre-treated with β-CM-7 was lower than in those that was not pre-treated (p <0.05). Accordingly, SOD was elevated in the cells pre-treated with β-CM-7. The relative expression of GSH-px increased with increases of Foxo1 and SP1.

CONCLUSION

β-CM-7 protects HLECs from oxidative damage by upregulating the relative expression of Foxo1 and promoting Foxo1 nuclear translocation.

Retrospective Analyses of Potential Risk Factors for Posterior Capsule Opacification after Cataract Surgery

PURPOSE

To evaluate the potential risk factors of posterior capsule opacification (PCO) after cataract surgery.

METHODS

Data on PCO patients diagnosed from September 2015 to May 2017 were obtained from the Department of Ophthalmology at Qingdao Municipal Hospital, Qingdao, China. The factors associated with PCO were assessed using Pearson's χ2 test for univariate analyses and logistic regression for multivariate analyses.

RESULTS

Eyes (652) from 550 patients were enrolled in this study. All patients were diagnosed with PCO/non-PCO and had <3 years of follow-up after surgery. The numbers of PCO and non-PCO were 108 eyes and 544 eyes, respectively. Statistically significant associations with PCO were found for age at the time of surgery (χ2 = 78.504; p < 0.001), diabetes (χ2 = 4.829; p=0.028), immune diseases (χ2 = 4.234; p=0.004), high myopia (χ2 = 5.753; p=0.016), lens nucleus hardness (χ2 = 11.046; p=0.026), surgery type (χ2 = 11.354; p=0.001), a history of vitrectomy (χ2 = 4.212; p=0.004), ocular inflammation (χ2 = 6.01; p=0.009), and the intraocular lens (IOL) type (χ2 = 8.696; p=0.003). Multivariable data analyses using logistic regression analyses of the variables showed that age at the time of surgery <60 years, diabetes, lens nucleus hardness of III-V, extracapsular cataract extraction (ECCE), postvitrectomy, and hydrophilic IOLs were significant independent risk factors associated with PCO.

CONCLUSIONS

Age <60 years, diabetes, lens nucleus hardness of III-V, ECCE, postvitrectomy, and a hydrophilic IOL were significantly associated with the formation of PCO. Estimation of the incidence of and risk factors for PCO should help in patients counseling and in the design of treatment protocols to reduce or prevent its development.

Cataract Surgery in Patients with Diabetes: Management Strategies

Diabetes is a chronic systemic disease that affects nearly one in eight adults worldwide. Ocular complications, such as cataract, can lead to significant visual impairment. Among the worldwide population, cataract is the leading cause of blindness, and patients with diabetes have an increased incidence of cataracts which mature earlier compared to the rest of the population. Cataract surgery is a common and safe procedure, but can be associated with vision-threatening complications in the diabetic population, such as diabetic macular edema, postoperative macular edema, diabetic retinopathy progression, and posterior capsular opacification. This article is a brief review of diabetic cataract and complications associated with cataract extraction in this population of patients.

Phacoemulsification without preoperative mydriasis in patients with age-related cataract associated with type 2 diabetes

Aim

To study the effect of intracameral injection of preservative-free lignocaine to induce pupil dilatation, without using any preoperative dilating eyedrops or intraoperative mydriatics in patients with age-related cataract associated with type 2 diabetes mellitus.

Design

This was a prospective, observational, and interventional case series conducted at a tertiary eyecare center in rural India.

Materials and methods

A total of 32 patients underwent phacoemulsification under topical anesthesia for visually significant cataract. Preoperative pupillary diameter was measured 3 days prior to surgical procedure under mydriatics (tropicamide 0.8%, phenylephrine hydrochloride 5%). Intraoperative pupillary dilatation was achieved by 1% intracameral lignocaine solution alone. Effective phacoemulsification time (EPT), total surgical time, and final pupillary diameter were recorded at the conclusion of surgery.

Results

The average duration of diabetes was 11.2 (range 5–25) years. There was no difference in dilatation by preoperative pupil-dilating drops (5.2±0.5 mm, range 3–8.3 mm) and intracameral 1% lignocaine during the surgical procedure (P=0.63). There was a negative correlation (r=−0.92) between diabetes duration and dilatation of pupils with dilating drops and intracameral lignocaine. The duration of the surgery, EPT, and phacoemulsification chop had statistically insignificant effects on mydriasis, while the grade of the nucleus had a statistically significant effect on mydriasis. Intracameral lignocaine had no significant effect on blood pressure or pulse. There were no surgical complications that could have compromised the visual outcome. None of the patients developed macular edema in a follow-up period of 3 months; 28 patients (87.5%) had best-corrected visual acuity from 20/30 to 20/20.

Conclusion

Intracameral lignocaine 1% provides sufficient mydriasis for the safe phacoemulsification of cataract in patients with type 2 diabetes of variable duration.

Comparison of posterior capsule opacification at 360-degree square edge hydrophilic and sharp edge hydrophobic acrylic intraocular lens in diabetic patients

AIM

To compare posterior capsule opacification (PCO) degree and visual functions after phacoemulsification in eyes implanted with 360-degree square edge hydrophilic acrylic intraocular lens (IOL) (570C C-flex, Rayner) and sharp edge hydrophobic acrylic IOL (Sensar AR40e, AMO) in diabetic patients.

METHODS

Sixty diabetic patients underwent uneventful phacoemulsification and randomly implanted one of the two IOLs. The PCO value was measured by retroillumination photographs and Evaluation of Posterior Capsule Opacification (EPCO) 2000 image-analysis software at 1, 6, 12, and 24mo after surgery. Visual acuity, and contrast sensitivity in photopic and mesopic conditions were also examined at each follow up time point. The incidence of eye that required Nd:YAG laser posterior capsulotomy were also compared.

RESULTS

There was not any statistically significant difference in PCO scores between Rayner C-flex 570C group and Sensar AR40e group at each follow up time point. Visual acuity, Nd:YAG capsulotomy incidence and contrast sensitivity also had no significant difference during the 24mo follow-up.

CONCLUSION

For diabetic patients, Rayner 570C C-flex and Sensar AR40e IOLs are same effective for prevent PCO. The 360-degree square edge design maybe is a good alternative technique to improve PCO prevention.

[Posterior capsule opacification, capsular bag distension syndrome, and anterior capsular phimosis: A retrospective cohort study]

OBJECTIVE

To determine the incidence and the risk factors involved in the development of the three main postoperative capsular complications: posterior capsule opacification (PCO), capsular bag distension syndrome (CBDS), and anterior capsular phimosis syndrome (ACP).

SUBJECTS, MATERIAL AND METHODS

A retrospective cohort study was conducted on 801 patients submitted to cataract surgery in the ophthalmology unit of Hospital del Henares (Madrid) from March 2, 2009 to February 28, 2010. Computerized clinical charts were reviewed during July 2012. PCO was studied using the Kaplan-Meier method (log rank test).

RESULTS

A total of 167 patients developed PCO. No association could be demonstrated between PCO and age, sex, diabetes mellitus, phaco technique, IOL model, tamsulosin intake, glaucoma, and age-related macular degeneration. Three patients developed CBDS, all of them have received and Akreos Adapt AO(®) (Bausch & Lomb). Two of them were young men who had received surgery for posterior subcapsular cataracts. Three patients developed ACP, 2 of whom had received a MicroSlim(®) IOL (PhysIOL).

CONCLUSIONS

No association was found between PCO and any of the studied variables. Male gender, young age, subcapsular cataract and large non-angulated lens such as Akreos Adapt AO(®) could be associated with CBDS. ACP could be more frequent when microincision IOLs (like MicroSlim(®)) are implanted.

In vitro growth of lens epithelial cells from cataract patients - association with possible risk factors for posterior capsule opacification

AIM

Inter-individual differences in intrinsic proliferative capacity of lens epithelial cells may have importance for the risk of developing posterior capsule opacification (PCO) after cataract surgery. The purpose of the present study was to determine growth of human lens epithelial cells (HLEC) in culture and investigate possible associations with clinical characteristics of the donors, such as age, sex, pseudoexfoliation, uveitis and diabetes.

METHODS

Pieces of lens capsule and adhering lens epithelial cells were obtained through capsulorhexis at cataract surgery. Specimens were cultured in a humidified CO2-incubator using standard culture medium and 5% fetal calf serum for two weeks after which cultured cells were stained with carboxy-fluorescein diacetate succinimidyl ester. Image processing software was used to determine the area of the confluent epithelial cell layer in relation to the size of the original capsule specimen.

RESULTS

The increase in area of confluent HLEC showed a negative correlation with diabetes at the first week after surgery. Lower age and female sex showed border-line significant associations with a higher rate of cell proliferation. The presence of pseudoexfoliation in vivo did not significantly affect cell growth in culture postoperatively. Nor did installation of xylocain in the anterior chamber during surgery.

CONCLUSION

Diabetes is associated with lower rate of proliferation of lens epithelial cells in culture. The lack of strong correlations between in vitro growth and known risk factors for PCO in the donors suggest that other factors than the proliferative capacity of the cells per se are important for PCO formation.

A prospective evaluation of posterior capsule opacification in eyes with diabetes mellitus: a case-control study

AIM

To compare the development of posterior capsule opacification (PCO) between eyes with and without diabetes mellitus after single-piece hydrophobic acrylic intraocular lens implantation 4 years postoperatively.

METHODS

In this prospective, observational case-control study carried out at Iladevi Cataract and IOL Research Centre, Ahmedabad, India, 75 consecutive eyes with diabetes mellitus (cases) were compared with 75 age-matched eyes with age-related cataract (controls). A detailed, preoperative and posterior segment evaluation was carried out in eyes with diabetes mellitus to detect the presence or absence of diabetic retinopathy (DR). The Mann-Whitney U-test was applied to compare the differences in the development of PCO between the two groups.

RESULTS

There was no difference in median PCO between cases and controls at 1 month (2.0 vs 1.50, P<0.068), but cases had a higher median PCO at 12 months (2.95 vs 1.30, P<0.001). At 4 years, there was no significant difference in median PCO between cases and controls (3.75 vs 2.25, P=0.273). The duration of diabetes increased the incidence of PCO at 4 years (P=0.02). Severity of DR had no influence on the progress of PCO at 4 years (P=0.69).

CONCLUSION

Diabetes mellitus did not increase the incidence of PCO at 4 years. The duration of diabetes increased the risk of PCO. The severity of retinopathy did not influence the development of PCO.

Three-year incidence and factors associated with posterior capsule opacification after cataract surgery: The Australian Prospective Cataract Surgery and Age-related Macular Degeneration Study

PURPOSE

To assess 3-year incidence and associated factors of posterior capsule opacification (PCO) after phacoemulsification surgery.

DESIGN

Cohort study.

METHODS

A total of 1934 consecutive patients aged ≥64 years undergoing phacoemulsification surgery at Westmead Hospital were recruited, of whom 1495 (77.3%) had retroillumination anterior segment images taken of the surgical eyes after 1 month and at a further postoperative visit within 3 years. Severe PCO was defined if the view of the optic disc was obscured, or neodymium-yttrium-aluminum-garnet capsulotomy was performed. Cumulative incidence of PCO was estimated using Kaplan-Meier methods. Associations of PCO with surgeon groups and different types of implanted intraocular lenses (IOLs) were assessed, adjusting for age, sex, diabetes, and ethnicity.

RESULTS

Three-year cumulative incidence of PCO was 38.5% (95% confidence interval [CI] 36.1%-40.9%) among the 1495 patients, including 4.7% (95% CI 3.5%-5.8%) with severe PCO. PCO incidence was higher in: (1) eyes operated on by junior trainees (49%) compared to those by senior ophthalmologist surgeons (36%) (adjusted odds ratio [OR] 1.6, 95% CI 1.2-2.0); and (2) eyes with hydrophobic, 3-piece (either square-edged [51%, OR 2.3, 95% CI 1.4-3.6] or partial-round-edged [39%, OR 1.5, 95% CI 1.1-2.1]), or hydrophilic IOLs (64%, OR 2.9, 95% CI 1.9-4.4) compared to those with single-piece, square-edged, hydrophobic IOLs (34%), after additional adjustment for surgeon group.

CONCLUSIONS

Predominantly mild PCO occurred in one-third of eyes after phacoemulsification surgery. Possible predisposing factors associated with PCO development include surgery performed by ophthalmologic trainees and the use of hydrophilic or other hydrophobic IOLs apart from the single-piece, square-edged one.

Posterior capsule opacification in eyes with steroid-induced cataracts: Comparison of early results

PURPOSE

To evaluate posterior capsule opacification (PCO) development after cataract surgery in eyes with or without a history of steroid use.

SETTING

Iladevi Cataract & IOL Research Centre, Ahmedabad, India.

DESIGN

Comparative case series.

METHODS

This study comprised consecutive patients with a history of steroid intake (oral, inhaled, injectable, or topical) for at least 4 months who developed posterior subcapsular cataract (PSC) (study group) and patients without a history of steroid intake with uncomplicated PSC (control group). Standardized surgery was performed in both groups. Digital retroillumination photographic documentation was performed 1 month and 1 year postoperatively. The digital images were analyzed for PCO using Evaluation of Posterior Capsule Opacification (EPCO) software; the entire intraocular lens (IOL) optic and the central 3.0 mm optic area were evaluated. The EPCO score and EPCO area were determined.

RESULTS

One year postoperatively, the mean EPCO score was statistically significantly higher in the study group (n = 30) than in the control group (n = 60) (0.33 ± 0.37 [SD] versus 0.15 ± 0.26), as was the mean EPCO area (0.323 ± 0.36 versus 0.15 ± 0.26) (both P<.04). Within the central 3.0 mm optic area, the mean EPCO scores (0.149 ± 0.309 versus 0.003 ± 0.016 P<.04) and mean EPCO area values (0.149 ± 0.309 versus 0.003 ± 0.016) were statistically significantly higher in the study group (P<.04).

CONCLUSION

Steroid-induced PSC was associated with a higher risk for PCO after cataract surgery at the 1-year follow-up.

FINANCIAL DISCLOSURE

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

Prevalence and predictors of ocular complications associated with cataract surgery in United States veterans

PURPOSE

To investigate the prevalence and predictors of intraoperative and 90-day postoperative ocular complications associated with cataract surgery performed in the United States Veterans Health Administration (VHA) system.

DESIGN

Retrospective cohort study.

PARTICIPANTS

Forty-five thousand eighty-two veterans who underwent cataract surgery in the VHA.

METHODS

The National Patient Care Database was used to identify all VHA patients who underwent outpatient extracapsular cataract surgery and who underwent only 1 cataract surgery within 90 days of the index surgery between October 1, 2005, and September 30, 2007. Data collected include demographics, preoperative systemic and ocular comorbidities, intraoperative complications, and 90-day postoperative complications. Adjusted odds ratios (ORs) of factors predictive of complications were calculated using logistic regression modeling.

MAIN OUTCOME MEASURES

Intraoperative and postoperative ocular complications within 90 days of cataract surgery.

RESULTS

During the study period, 53786 veterans underwent cataract surgery; 45082 met inclusion criteria. Common preoperative systemic and ocular comorbidities included diabetes mellitus (40.6%), chronic pulmonary disease (21.2%), age-related macular degeneration (14.4%), and diabetes with ophthalmic manifestations (14.0%). The most common ocular complications were posterior capsular tear, anterior vitrectomy, or both during surgery (3.5%) and posterior capsular opacification after surgery (4.2%). Predictors of complications included: black race (OR, 1.38; 95% confidence interval [CI], 1.28-1.50), divorced status (OR, 1.10; 95% CI, 1.03-1.18), never married (OR, 1.26; 95% CI, 1.14-1.38), diabetes with ophthalmic manifestations (OR, 1.33; 95% CI, 1.23-1.43), traumatic cataract (OR, 1.80; 95% CI, 1.40-2.31), previous ocular surgery (OR, 1.29; 95% CI, 1.02-1.63), and older age.

CONCLUSIONS

In a cohort of United States veterans with a high preoperative disease burden, selected demographic factors and ocular comorbidities were associated with greater risks of cataract surgery complications. Further large-scale studies are warranted to investigate cataract surgery outcomes for non-VHA United States patient populations.

Two-year follow-up of posterior capsule opacification after implantation of a hydrophilic or hydrophobic acrylic intraocular lens

PURPOSE

To evaluate posterior capsule opacification (PCO) 2 years after cataract surgery following implantation of a hydrophilic or a hydrophobic single-piece acrylic intraocular lens (IOL) with a sharp edge.

METHODS

Phacoemulsification cataract surgery was performed in one eye of 120 patients with senile cataract in this prospective study. They were randomized to implantation of either a hydrophilic acrylic IOL (BL27; Bausch & Lomb, Rochester, NY, USA) or a hydrophobic acrylic IOL (AcrySof) SA60AT; Alcon Laboratories, Fort Worth, TX, USA). Two years after surgery, retroillumination images were obtained and PCO area and severity were evaluated using pocoman software. Best corrected visual acuity (VA) (both high-contrast [100%] and low-contrast [2.5%]), glare, laser flare and intraocular pressure were measured. Capsulotomy rates were recorded.

RESULTS

Patients implanted with the hydrophilic IOL had a greater percentage area and severity of PCO compared with patients with the hydrophobic IOL (p < 0.001). There was no difference in PCO between men and women in the hydrophilic group. However, in the hydrophobic group, women had significantly more PCO than men (p < 0.05). Patients with the hydrophobic acrylic IOL had better high- and low-contrast visual activity (VA) (p < 0.01) and less glare (p < 0.001) than those with a hydrophilic acrylic IOL. Of the patients with the hydrophilic IOL, 42% underwent capsulotomy, compared with 10% in the hydrophobic group (p < 0.001).

CONCLUSIONS

Two years after surgery, patients with the SA60AT hydrophobic acrylic IOL had less PCO and better high- and low-contrast VA than patients with the BL27 hydrophilic acrylic IOL.

Incidence and risk factors of Nd:YAG capsulotomy after phacoemulsification in non-diabetic and diabetic patients

PURPOSE

To estimate the cumulative incidence and identify the risk factors of posterior capsule opacification (PCO) that required Nd:YAG capsulotomy in non-diabetic and diabetic patients.

METHODS

Retrospective case-note review of 806 consecutive patients that underwent phacoemulsification and intraocular lens (IOL) implantation, 327 (40.6%) of whom were diabetic.

RESULTS

The cumulative incidence of Nd:YAG capsulotomy were 10.6%, 14.8%, 21.2% and 28.6% in non-diabetic patients; and 9%, 9.4%, 15.3% and 5.3% in diabetic patients after 1, 2, 3 and 4 years, respectively. A multivariate Cox regression analysis showed that, over the follow-up period, diabetes mellitus was associated with a decreased risk of Nd:YAG capsulotomy (hazard ratio [HR]=0.69; 95% confidence interval [CI] 0.47-0.99; P=0.047), whereas age of 65 years or younger (HR=1.58; 95% CI 1.09-2.27; P=0.02), polymethylmethacrylate (PMMA) (HR=3.98; 95% CI 1.60-9.95; P=0.003) or plate-haptic silicone IOLs (HR=3.75; 95% CI 1.60-8.80; P=0.002) in comparison with three-piece silicone IOLs, postoperative inflammation (HR=2.62; 95% CI 1.56-4.42; P<0.001) and pars plana vitrectomy (HR=1.85; 95% CI 1.20-2.83; P=0.005) were associated with an increased risk. Subgroup analysis showed that in non-diabetic patients, male gender (HR=1.63; 95% CI 1.04-2.57; P=0.03) was an additional risk factor and in diabetic patients there was no significant association between diabetes type, duration or retinopathy grade and the risk of Nd:YAG capsulotomy.

CONCLUSION

Although diabetes mellitus appears to be associated with a lower long-term incidence and a decreased risk of Nd:YAG capsulotomy, younger age, pars plana vitrectomy, postoperative inflammation, plate-haptic silicone and PMMA IOLs in addition to male gender in non-diabetic patients appear to be associated with a greater risk. Estimation of the incidence and risk factors of PCO should help in patient counselling and to design methods to reduce or prevent its development.

Posterior capsular opacification in diabetic and nondiabetic canine patients following cataract surgery

Posterior capsular opacification (PCO) is the most common postoperative complication of contemporary cataract surgery. Limited information is available regarding PCO formation and factors that influence PCO development in the dog. Two hundred sixty-five eyes (144 from diabetic dogs and 121 from dogs with breed-related cataracts) were prospectively evaluated for PCO formation for up to 12 months postoperatively. The mean age of all dogs in the study was 7.77 years and diabetic dogs were significantly older than dogs with breed-related cataracts. There were 73 males (61 neutered, 12 intact) and 74 females (70 neutered, 4 intact) in the study. Statistical analysis was performed based on age, breed/size, gender, stage of cataract at the time of surgery, PCO score at each time point, breed-related vs. diabetic cataract, right eyes compared to left eyes, and presence/absence of uveitis. Age and gender did not significantly influence PCO formation. Small and medium-sized breeds developed significantly more PCO in comparison to the large/giant breeds at 2 weeks and 2-4 months postoperatively, but the differences were not significant at later time points. There was an overall significant increase in PCO formation in eyes with early immature cataracts when compared to other stages of cataract up to 4 months postoperatively but not at later time points. There were no statistical differences in PCO score at 6 months or at 1 year postoperatively in eyes with breed-related and diabetic cataracts. Right eyes did not differ from left eyes in PCO score. PCO score significantly increased over time in breed-related and diabetic groups and in the overall population. No difference was found in the degree of PCO formation in eyes with inflammation prior to or after surgery compared with those without inflammation. In summary, age, gender, presence of inflammation, and cause of cataract (breed-related vs. diabetes mellitus) do not influence the development of PCO in canine cataract dogs. Small and medium-sized breeds develop significant PCO earlier than larger breeds. It is important to note that all eyes from all dogs in this study developed PCO in a time dependent manner.

Posterior capsule opacification after cataract surgery in patients with diabetes mellitus

PURPOSE

To prospectively compare the degree of posterior capsule opacification (PCO) after cataract surgery in patients with and without diabetes mellitus.

SETTING

Sugita Eye Hospital, Nagoya, Japan.

METHODS

Forty-two eyes of 42 consecutive diabetes mellitus patients (DM group) and 42 eyes of 42 non-DM patients (control group) scheduled to have cataract surgery were enrolled. The PCO value was determined using the posterior capsule opacification (POCO) system 3, 6, and 12 months after surgery.

RESULTS

Posterior capsule opacification values 3 months after surgery did not differ significantly between the 2 groups (P>.05). At 6 and 12 months, the PCO values of the DM group were significantly higher than those of the control group (P = .002 and P = .03, respectively).

CONCLUSION

Diabetic patients had significantly more severe PCO after cataract surgery than nondiabetic patients.

[Posterior capsule opacification after phacoemulsification in patients with rheumatoid arthritis]

PURPOSE

To assess the posterior capsule opacification (PCO) rate after phacoemulsification with polyacrylic intraocular lens (IOL) implantation in patients with rheumatoid arthritis (RA) compared with the controls, and to assess whether preoperative activity of RA is associated with a higher incidence of PCO.

METHODS

24 eyes of 20 RA patients operated in a period of 4 years were included in our study. A control group of 20 eyes from 20 health subjects were also included in our study. All procedures were performed by a single surgeon with the same surgical technique and postoperative medication.

RESULTS

One year postoperatively in two eyes (8.3%) of RA-patients lens epithelial cells (LEC) migration of grade 1 was observed, in controls also in two eyes (10%). No correlation was observed between age, duration of RA or preoperative activity of RA and the PCO rate.

CONCLUSION

Following acrylic IOL implantation, the PCO rate one year after surgery was 8.3% in RA patients and 10% in controls. RA patients present no higher risk for PCO development than controls.

Chirurgie combinée phacoexérèse, vitrectomie et implantation chez le patient diabétique avec phacoémulsification versus phacophragmentation

INTRODUCTION

In diabetic patients, we often need to perform cataract and pars plana vitrectomy. Two different techniques are currently valid: 1) phacoemulsification and pars plana vitrectomy and 2)pars plana lensectomy and posterior vitrectomy.

METHODS

Retrospective study of two different groups of type 2 diabetic patients: those receiving 1) phacoemulsification and pars plana vitrectomy or 2) pars plana lensectomy and posterior vitrectomy.

RESULTS

On statistical analysis there were no differences in complications between the two groups. The effect on visual acuity was similar in both groups.

DISCUSSION

The association of cataract surgery and posterior vitrectomy is a valid technique for treating diabetic retinopathy complications. In the present study, the complications of the two techniques were similar, the most important concerning only anterior chamber opening in the first group.

CONCLUSION

The two techniques of cataract extraction and pars plana vitrectomy at the same time have no differences in their results and are valid for treatment of diabetic patients.

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.

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.

Relationship between posterior capsule opacification and intraocular lens biocompatibility

The type of healing process that occurs in response to cataract surgery and intraocular lens (IOL) implantation is dependent on a complex set of variables. Their interactions determine whether or not optical clarity is restored as a result of this procedure. In this process, wound healing entails cells undergoing either epithelial-mesenchymal transition, resulting in the generation of fibroblastic cells and accumulation of extracellular matrix, or lenticular structure formation. Such desperate cellular behaviors are regulated by the localized release of different cytokines, including transforming growth factor beta and fibroblast growth factors, which can result in post-operative capsular opacification. Other factors affecting the biological and mechanical outcome of IOL implantation are its composition, surface properties and shape.

Posterior capsule opacification after phacoemulsification in patients with postoperative steroidal and nonsteroidal treatment

PURPOSE

To evaluate the effect of dexamethasone, diclofenac, and a placebo given for 3 weeks after phacoemulsification and intraocular lens (IOL) implantation on the formation of posterior capsule opacification (PCO).

SETTING

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

METHODS

In a 2-year prospective randomized double-blind study, a laser flare meter was used to measure aqueous flare intensity preoperatively and 3 days, 2 weeks, and 2 years after phacoemulsification and IOL implantation. Posterior capsule opacification was evaluated 2 years postoperatively using retroillumination images taken with a Scheimpflug camera. The Evaluation of Posterior Capsule Opacification system was used to score the areas of PCO density.

RESULTS

The median rate of PCO 2 years after phacoemulsification was 0.72 (range 0.32 to 1.57) in the dexamethasone group, 0.78 (range 0.19 to 2.14) in the diclofenac group, and 0.70 (range 0.35 to 1.70) in the placebo group. The differences were not statistically significant (P>.05; Kruskal-Wallis analysis of variance, multiple comparisons). The rate of neodymium:YAG laser posterior capsulotomy during the 2 years after surgery was not statistically different between groups (P>.05, chi-square test). There was no correlation (Spearman rank coefficient) between laser flare measurements and PCO formation in any group during the study (P>.05).

CONCLUSION

Topical instillation of diclofenac, dexamethasone, or a placebo in the immediate period after phacoemulsification and IOL implantation did not seem to influence the formation of PCO 2 years after cataract surgery.

Posterior capsule opacification after cataract surgery in patients with diabetes mellitus

PURPOSE

To examine the degree of posterior capsule opacification (PCO) after cataract surgery in patients with diabetes and in nondiabetic age-matched control patients.

DESIGN

Case-control study.

METHODS

The PCO density value in 100 consecutive diabetic patients and in 100 nondiabetic age-matched control patients who underwent cataract surgery was measured using a Scheimpflug videophotography system at 1 week and at 3, 6, 12, 18, 24, 30, and 36 months after surgery. The incidence of neodymium:yttrium-aluminum-garnet (Nd:YAG) laser posterior capsulotomy was also evaluated. Furthermore, the stage of diabetic retinopathy and systemic condition of the diabetes were correlated with the degree of PCO.

RESULTS

No significant difference between the two groups was observed in the mean value of the PCO for up to 12 months after cataract surgery. However, at 18 months and later, the PCO value in the diabetic group increased significantly and was significantly greater than in the control group. Kaplan-Meier survival curves showed that diabetic patients were significantly more likely to require Nd:YAG capsulotomy than control patients (P =.0139, Mantel-Cox log rank test). Among the diabetic patients, there was no significant correlation of PCO value with the stage of retinopathy. Furthermore, type of treatment, duration of diabetes, and hemoglobin A(1C) did not correlate with the PCO value.

CONCLUSIONS

Diabetic patients developed significantly greater PCO after cataract surgery than did nondiabetic patients, but among the diabetics, the stage of diabetic retinopathy and systemic status of the diabetes did not correlate with the degree of PCO.

Posterior capsular opacification in pseudophakic eyes with a silicone or acrylic intraocular lens

PURPOSE

To compare posterior capsular opacification in eyes with IOL of two different materials--silicone or acrylic.

METHODS

Eighty consecutive eyes undergoing cataract surgery were prospectively randomized in two groups, 40 eyes receiving a silicone (Sl--30NB) and 40 eyes an acrylic (Acrysof MA60BM) intraocular lens (IOL). The same surgeon performed phacoemulsification and the intraocular lens (PHACO IOL) operation in all cases. Patients were re-examined on the first postoperative day, after one week, four months, and 1-2.4 years. Seven eyes were lost to late control.

RESULTS

Clinically significant posterior capsular opacification (PCO) (including eyes with capsulotomy already performed) was equally common in both groups; 25% in the silicone group and 19% in the acrylic group (p=0.53). The posterior capsule remained clear in 61% of the silicone and 76% of the acrylic IOL eyes (p=0.18). In the whole study group, 29% of eyes with and 14% without concurrent ocular diseases had significant PCO (p=0.13). In the silicone IOL group, PCO was more common in eyes with concurrent ocular diseases (44%) than eyes without other diseases (10%) (p=0.049). Eyes with acrylic IOL showed no difference in significant PCO, with or without other diseases (18% and 20%, respectively).

CONCLUSIONS

In a consecutive series of 80 cataract eyes central PCO was equally common in eyes receiving a silicone or an acrylic IOL. In the silicone IOL group, however, significant PCO was more common if there was concurrent ocular disease, while with the acrylic IOL concurrent ocular disease did not seem to increase the risk of PCO.

Posterior capsule opacification with AcrySof and poly(methyl methacrylate) intraocular lenses. Comparative study with a 3-year follow-up

PURPOSE

To evaluate whether reports of reduced posterior capsule opacification (PCO) rates with AcrySof intraocular lenses (IOLs) are applicable to a mixed group of cataract patients in everyday surgical practice.

SETTING

Department of Ophthalmology, Kärnsjukhuset, Skövde, Sweden.

METHODS

A retrospective study comparing a study group receiving an AcrySof IOL (n = 145) and a group receiving a poly(methyl methacrylate) (PMMA) IOL (n = 153) was performed. The follow-up was 3 years in both groups. The performance of a neodymium:YAG laser capsulotomy was used as the end point for clinically significant PCO.

RESULTS

Nine capsulotomies (6.2%) were performed in the AcrySof group and 34 (22.2%) in the PMMA group. The difference in the capsulotomy rate between the 2 groups was highly significant (P <.001). The relative risk was 3.6 times higher in the PMMA group.

CONCLUSIONS

There was a significant difference in the frequency of capsulotomy between AcrySof and PMMA IOLs in a mixed group of cataract patients in everyday clinical practice. This finding indicates the importance of the IOL type in PCO formation.

Comparison of Scheimpflug images of posterior capsule opacification and histological findings in rabbits and humans

PURPOSE

To compare the posterior capsule opacification in Scheimpflug photographic images produced by an electronic anterior eye segment analysis system with the histopathological findings in rabbits and humans.

SETTING

Department of Ophthalmology, Wakayama Medical College, Japan.

METHODS

Opacified posterior capsules were photographed using the EAS-1000 system (Nidek) and were then extracted during vitreous surgery for proliferative diabetic retinopathy or proliferative vitreoretinopathy in 2 patients. In rabbits, phacoemulsification and aspiration (PEA) with intraocular lens (IOL) implantation was performed. The IOL was implanted in the bag or in the sulcus. After intervals of healing, the posterior capsule was photographed with the EAS-1000 and the animals were then killed. In both clinical and experimental specimens, the posterior capsule was processed for light microscopic histology and immunohistochemistry.

RESULTS

Opacified human capsules were well imaged by the EAS-1000. Histology showed that lens epithelial cells proliferated with and without an accumulation of extracellular matrix. Details such as rolling of the capsulotomy edge were seen well. Regenerated lens fibers of Soemmering's ring were seen as a mass within the capsule. In the rabbit model, Scheimpflug images accurately represented the capsules as they appeared histologically.

CONCLUSION

The EAS-1000 system provided faithful, relatively high-resolution images that corresponded to the histologic findings in the posterior capsules after PEA-IOL surgery in humans and rabbits.

Posterior capsule opacification and anterior capsule opacification

Posterior capsule opacification (PCO) is still the most frequent complication of cataract surgery. A variety of studies has led to a better understanding of the pathogenesis of PCO, and strategies of molecular biology have produced new therapeutic options, such as immunological techniques or gene therapeutic approaches. Surgical strategies and intra-ocular lens-dependent factors also are capable to reduce the rate of PCO. In-the-bag implantation of intra-ocular lenses with a sharp optic edge seems to be effective in inhibiting equatorial lens epithelial cell migration to the center of the posterior capsule. Several PCO documentation systems have been developed that will lead to more exact and better comparable recording of PCO rates. In the year 2000, PCO or secondary cataract is still the most frequent complication after extracapsular cataract surgery. In a 1998 meta-analysis, PCO rates of 11.8% 1 year after extracapsular cataract surgery with intraocular lens implantation, 20.7% after 3 years, and 28.4 % after 5 years have been reported. For the United States, it has been estimated that the overall expenses for treatment of PCO are only exceeded by the costs for cataract treatment itself. In the past decade, a lot of experimental and clinical studies have been performed on this topic. They have led to 1) to a better understanding of the pathogenesis of the development of anterior and posterior capsule opacification; 2) more objective and better comparable systems of documentation and analysis of PCO; and a number of 3) surgical and 4) pharmaceutical strategies to prevent PCO.