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

The Efficacy and Safety of Standard versus Soft Topical Steroids after Cataract Surgery: A Systematic Review and Meta-analysis

TOPIC

Review of the efficacy and safety of standard versus soft topical steroid application after cataract surgery.

CLINICAL RELEVANCE

The control of postoperative inflammation is the mainstay of treatment after cataract surgery. However, no consensus exists regarding the postoperative steroid of choice. Basing the choice of topical postoperative steroidal treatment on high-quality data regarding both risks and benefits of various drugs would be advantageous for both patients and clinicians.

METHODS

A systematic search of the PubMed, Scopus, and Embase electronic databases for all peer-reviewed published randomized control trials that included clinical outcomes of topical steroidal treatment after uneventful cataract surgery was performed. Individual study data were extracted and evaluated in a weighted pooled analysis including grading of total anterior chamber (AC) inflammation, AC cells, AC flare, postoperative visual acuity (VA), intraocular pressure (IOP), and rate of adverse events (AEs).

RESULTS

Overall, 508 studies were found, of which 7 were eligible for the systematic review and ultimately were included for analysis, reporting on 593 patients from 5 countries. Age of included patients, when available, ranged between 3.7 and 73.4 years. Follow-up data were available for analysis at 1, 7, and 28 days after surgery. Except for a significantly lower grade of AC flare in the standard steroid group at day 7 (standardized mean difference, 0.26; 95% confidence interval, 0.05-0.47; I2 = 0%), inflammatory activity measurements displayed insignificant differences at every other follow-up (days 1 and 28 after surgery). Pooled analysis of IOP at each follow-up demonstrated a higher IOP at the 7-day visit in the standard steroid group, whereas IOP at other time points was comparable among the groups. Qualitative analysis of ocular AEs showed similarities among the groups.

DISCUSSION

The findings of this study suggest that for the average patient, both groups produce a comparable effect on both AC inflammation and postoperative IOP and VA.

FINANCIAL DISCLOSURE(S)

The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Comparison of the Rate of Posterior Capsule Opacification Following Combined Treatment With Topical Dexamethasone 0.1% Plus Ketorolac 0.5% Eye Drops Versus Dexamethasone 0.1% Alone: A Two-Year, Randomized Clinical Investigation

Background and aim The use of non-steroidal anti-inflammatory drugs in animals decreases the incidence of posterior capsular opacification (PCO) following cataract surgery. We evaluated the rate of PCO in patients with cataract surgery and foldable "in the bag" posterior chamber intraocular lens (PC-IOL) implantation treated with combined dexamethasone 0.1% plus ketorolac tromethamine 0.5% versus dexamethasone 0.1% alone. Materials and methods A total of 114 eyes of 101 patients underwent uneventful corneal small-incision phacoemulsification with primary implantation of a foldable acrylic PC-IOL (AcrySof^®, Alcon, Fort Worth, USA). Postoperatively for four weeks, group 1 eyes were treated with dexamethasone 0.1% plus ketorolac tromethamine 0.5% ophthalmic solutions four times daily for each whereas group 2 eyes were treated with dexamethasone 0.1% alone. Other regiments were the same for each group. Patients were evaluated between one- and four-year following surgery. The frequency and timing of severe PCO following surgery that needed Nd:YAG laser posterior capsulotomy were recorded and evaluated. Results The mean (SEM) age of group 1 (n = 54) and group 2 (n = 60) at operation was similar (62.8 ± 2.2 vs. 60.6 ± 1.7 years, respectively). Eighty-eight patients had unilateral cataract and 13 cases had bilateral disease. Overall, the mean follow-up duration was 24.7 months postoperatively (range, 15-48). Clinically significant PCO that finally needed Nd:YAG laser application developed in two eyes (3.7%) in group 1 and in four eyes (6.6%) in group 2, and the difference was not statistically significant (p>0.05). The mean month at capsulotomy was 26.5 in group 1 and 24.3 months in group 2 eyes (p>0.05). Conclusions Topical instillation of ketorolac ophthalmic solution in the immediate period after phacoemulsification and PC-IOL implantation did not seem to influence the incidence of PCO formation two years after cataract surgery.

Oxidative stress induces inflammation of lens cells and triggers immune surveillance of ocular tissues

Recent reports have challenged the notion that the lens is immune-privileged. However, these studies have not fully identified the molecular mechanism(s) that promote immune surveillance of the lens. Using a mouse model of targeted glutathione (GSH) deficiency in ocular surface tissues, we have investigated the role of oxidative stress in upregulating cytokine expression and promoting immune surveillance of the eye. RNA-sequencing of lenses from postnatal day (P) 1-aged Gclc^f/f;Le-Cre^Tg/- (KO) and Gclc^f/f;Le-Cre^-/- control (CON) mice revealed upregulation of many cytokines (e.g., CCL4, GDF15, CSF1) and immune response genes in the lenses of KO mice. The eyes of KO mice had a greater number of cells in the aqueous and vitreous humors at P1, P20 and P50 than age-matched CON and Gclc^w/w;Le-Cre^Tg/- (CRE) mice. Histological analyses revealed the presence of innate immune cells (i.e., macrophages, leukocytes) in ocular structures of the KO mice. At P20, the expression of cytokines and ROS content was higher in the lenses of KO mice than in those from age-matched CRE and CON mice, suggesting that oxidative stress may induce cytokine expression. In vitro administration of the oxidant, hydrogen peroxide, and the depletion of GSH (using buthionine sulfoximine (BSO)) in 21EM15 lens epithelial cells induced cytokine expression, an effect that was prevented by co-treatment of the cells with N-acetyl-l-cysteine (NAC), a antioxidant. The in vivo and ex vivo induction of cytokine expression by oxidative stress was associated with the expression of markers of epithelial-to-mesenchymal transition (EMT), α-SMA, in lens cells. Given that EMT of lens epithelial cells causes posterior capsule opacification (PCO), we propose that oxidative stress induces cytokine expression, EMT and the development of PCO in a positive feedback loop. Collectively these data indicate that oxidative stress induces inflammation of lens cells which promotes immune surveillance of ocular structures.

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.

Immune cells in lens injury repair and fibrosis

Immune cells, both tissue resident immune cells and those immune cells recruited in response to wounding or degenerative conditions, are essential to both the maintenance and restoration of homeostasis in most tissues. These cells are typically provided to tissues by their closely associated vasculatures. However, the lens, like many of the tissues in the eye, are considered immune privileged sites because they have no associated vasculature. Such absence of immune cells was thought to protect the lens from inflammatory responses that would bring with them the danger of causing vision impairing opacities. However, it has now been shown, as occurs in other immune privileged sites in the eye, that novel pathways exist by which immune cells come to associate with the lens to protect it, maintain its homeostasis, and function in its regenerative repair. Here we review the discoveries that have revealed there are both innate and adaptive immune system responses to lens, and that, like most other tissues, the lens harbors a population of resident immune cells, which are the sentinels of danger or injury to a tissue. While resident and recruited immune cells are essential elements of lens homeostasis and repair, they also become the agents of disease, particularly as progenitors of pro-fibrogenic myofibroblasts. There still remains much to learn about the function of lens-associated immune cells in protection, repair and disease, the knowledge of which will provide new tools for maintaining the core functions of the lens in the visual system.

Anti-inflammatory Medication After Cataract Surgery and Posterior Capsular Opacification

PURPOSE

To assess the role of anti-inflammatory medication following cataract surgery on the formation of posterior capsular opacification.

DESIGN

Cohort study.

METHODS

A retrospective registry analysis of 25,818 consecutive patients who underwent cataract surgery between the years 2014 and 2018 at Helsinki University Hospital in Finland. Nd:YAG laser capsulotomy rates were compared between patients treated postoperatively with topical steroids, nonsteroidal anti-inflammatory medications (NSAIDs), or their combination. Kaplan-Meier and Cox regression analyses were used. A single eye of each patient was included. Main outcomes were confirmed against a second independent dataset.

RESULTS

A total of 13,368 patients were included in the analysis, with a mean age of 73.2 ± 9.7 years; 61.7% were female. Pseudoexfoliation was noted in 10.1% of cases. The mean follow-up time was 22.8 ± 15.7 months. Patients were treated with steroid monotherapy (28.9% of cases), NSAID monotherapy (62.2%), or a combination of both (8.9%). Treatment with steroids resulted in significantly lower Nd:YAG capsulotomy rates compared to NSAIDs (hazard ratio [HR] 0.76, 95% confidence interval [CI] 0.62-0.93, P = .009). Treatment with combination therapy of steroids and NSAIDs showed no added benefit over steroid monotherapy (HR 1.11, 95% CI 0.68-1.80, P = .674). Cox regression analysis adjusted for patients' age, sex, pseudoexfoliation, and risk stratification remained significantly predictive for lower capsulotomy rates with steroid treatment over NSAIDs (HR 0.70, 95% CI 0.52-0.88, P = .001).

CONCLUSIONS

Postoperative treatment with steroids among patients undergoing uncomplicated cataract surgery was associated with lower rates of clinically significant posterior capsule opacification compared to treatment with NSAIDs alone. Combination therapy of steroids and NSAIDs had no added benefit over steroids alone.

Efficacy of long-term topical flurbiprofen in limiting lens capsule opacities following phacoemulsification in dogs

OBJECTIVE

To assess lens capsule opacity (LCO) following phacoemulsification in dogs receiving long-term topical ophthalmic flurbiprofen sodium 0.03%.

ANIMAL STUDIED

Twenty-five client owned dogs undergoing phacoemulsification surgery for either diabetic or nondiabetic cataracts.

METHODS

Prospective, randomized, masked clinical study assessing two groups of dogs for twelve months following phacoemulsification. All dogs underwent a complete eye examination and were photographed at each visit, beginning three weeks post-surgery, and repeated at 2, 3, 6, and 12 months post-surgery. Post-operative treatment protocols were similar for both groups, except that Group F received topical flurbiprofen once daily for 12 months and Group A received artificial tears once daily for 12 months. Digital photographs were analyzed for LCO using a subjective grading scale (0-4). The change in capsular opacities from 3 weeks to 12 months post-surgery was evaluated for each dog, and the groups were compared.

RESULTS

There were 25 dogs evaluated post-phacoemulsification at each designated time point of the study. There were 12 dogs in Group A and 13 dogs in Group F. There was no significant statistical difference in LCO score between Groups A and F at baseline (3 weeks post-surgery), 6 months post-surgery, or 12 months post-surgery. Scores did not change significantly from baseline to 12 months within or between groups.

CONCLUSIONS

Topical ophthalmic flurbiprofen sodium 0.03% solution applied once daily for 12 months following phacoemulsification does not appear to lead to a decrease in LCO formation as compared to artificial tears control.

Lens Epithelial Cells Initiate an Inflammatory Response Following Cataract Surgery

Purpose

Lens epithelial cell (LEC) conversion to myofibroblast is responsible for fibrotic cataract surgery complications including posterior capsular opacification. While transforming growth factor beta (TGFβ) signaling is important, the mechanisms by which the TGFβ pathway is activated post cataract surgery (PCS) are not well understood.

Methods

RNA-seq was performed on LECs obtained from a mouse cataract surgery model at the time of surgery and 24 hours later. Bioinformatic analysis was performed with iPathwayGuide. Expression dynamics were determined by immunofluorescence.

Results

The LEC transcriptome is massively altered by 24 hours PCS. The differentially expressed genes included those important for lens biology, and fibrotic markers. However, the most dramatic changes were in the expression of genes regulating the innate immune response, with the top three altered genes exhibiting greater than 1000-fold upregulation. Immunolocalization revealed that CXCL1, S100a9, CSF3, COX-2, CCL2, LCN2, and HMOX1 protein levels upregulate in LECs between 1 hour and 6 hours PCS and peak at 24 hours PCS, while their levels sharply attenuate by 3 days PCS. This massive upregulation of known inflammatory mediators precedes the infiltration of neutrophils into the eye at 18 hours PCS, the upregulation of canonical TGFβ signaling at 48 hours PCS, and the infiltration of macrophages at 3 days PCS.

Conclusions

These data demonstrate that LECs produce proinflammatory cytokines immediately following lens injury that could drive postsurgical flare, and suggest that inflammation may be a major player in the onset of lens-associated fibrotic disease PCS.

[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.

Efficacy of COX-2 inhibitors in controlling inflammation and capsular opacification after phacoemulsification cataract removal

OBJECTIVE

To evaluate the efficacy of 0.9% bromfenac (Xibrom™) or a celecoxib-impregnated intraocular lens (celecoxib-IOL) compared with 1% prednisolone acetate (PA) in controlling postoperative inflammation and posterior capsule opacification (PCO).

ANIMAL STUDIED

Fifty-nine dogs undergoing cataract extraction by phacoemulsification.

PROCEDURE

Bilateral patients received bromfenac or celecoxib-IOL plus PA in one eye, and PA in the contralateral eye. Unilateral patients received bromfenac or PA. Complete ophthalmic examination including tonometry, slit-lamp grading of flare and PCO, and digital image acquisition for masked PCO evaluation was performed within 24 h and 1, 4, 12, 24, and 56 weeks following surgery.

RESULTS

Celecoxib-IOL/PA-treated eyes had significantly less flare than PA-treated eyes, which had significantly less flare than bromfenac-treated eyes 24 h postoperatively. There was no significant difference in intraocular pressure (IOP) postoperatively, or at 1, 24, or 56 weeks. Celecoxib-IOL/PA-treated eyes had significantly lower IOP measurements than bromfenac and PA-treated eyes at 4 and 12 weeks. There was no significant difference in PCO level between groups using slit-lamp biomicroscopy at any time point. Masked evaluation of digital images revealed significantly less PCO in celecoxib-IOL/PA- vs. bromfenac-treated eyes at 4 weeks, and in bromfenac- vs. PA-treated eyes at 56 weeks.

CONCLUSIONS

Eyes receiving celecoxib-IOL/PA had better initial control of inflammation. Bromfenac was equally effective compared with PA in controlling inflammation. There was no association between COX-2 inhibitor administration and ocular hypertension. Celecoxib-IOL/PA-treated eyes showed better initial control of PCO (up to 12 weeks), while eyes receiving bromfenac had better long-term control of PCO (56 weeks).

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.

Interventions for preventing posterior capsule opacification

BACKGROUND

Posterior capsule opacification (PCO) remains the most common long-term complication after cataract surgery. It can be treated by Nd:YAG laser capsulotomy, however this may lead to other complications and laser treatment is not available in large parts of the developing world. Therefore, many studies try to find factors influencing the development of PCO.

OBJECTIVES

To summarise the effects of different interventions to inhibit PCO. These include modifications of surgical technique and intraocular lens (IOL) design, implantation of additional devices and pharmacological interventions.

SEARCH STRATEGY

We searched CENTRAL, MEDLINE, EMBASE, LILACS in March 2009 and reference lists of identified trial reports.

SELECTION CRITERIA

We included only prospective, randomised and controlled trials with a follow-up time of at least 12 months. Interventions included modifications in surgical technique explicitly to inhibit PCO, modifications in IOL design (material and geometry), implantation of additional devices and pharmacological therapy compared to each other, placebo or standard treatment.

DATA COLLECTION AND ANALYSIS

We extracted data and entered it into RevMan. We compared visual acuity data, PCO scores and YAG capsulotomy rates and performed a meta-analysis when possible.

MAIN RESULTS

Sixty six studies were included in the review. The review was divided into three parts. 1. Influence of IOL optic material on the development of PCO. There was no significant difference in PCO development between the different IOL materials (PMMA, hydrogel, hydrophobic acrylic, silicone) although hydrogel IOLs tend to have higher PCO scores and silicone IOLs lower PCO scores than the other materials. 2. Influence of IOL optic design on the development of PCO. There was a significantly lower PCO score (-8.65 (-10.72 to -6.59), scale 0 to 100) and YAG rate (0.19 (0.11 to 0.35)) in sharp edged than in round edged IOLs, however not between 1-piece and 3-piece IOLs. 3. Influence of surgical technique and drugs on the development of PCO. There was no significant difference between different types of intraoperative/postoperative anti-inflammatory treatment except for treatment with an immunotoxin (MDX-A) which led to a significantly lower PCO rate.

AUTHORS' CONCLUSIONS

Due to the highly significant difference between round and sharp edged IOL optics, IOLs with sharp (posterior) optic edges should be preferred. There is no clear difference between optic materials. The choice of postoperative anti-inflammatory treatment does not seem to influence PCO development.

Interventions for preventing posterior capsule opacification

BACKGROUND

Posterior capsule opacification (PCO) remains the most common long-term complication after cataract surgery. It can be treated by Nd:YAG laser capsulotomy, however, this may lead to other complications and laser treatment is not available in large parts of the developing world. Therefore, many studies try to find factors influencing the development of PCO.

OBJECTIVES

To summarise the effects of different interventions to inhibit PCO. These include modifications of surgical technique and intraocular lens (IOL) design, implantation of additional devices and pharmacological interventions.

SEARCH STRATEGY

We searched CENTRAL, MEDLINE, EMBASE, LILACS in January 2007 and reference lists of identified trial reports.

SELECTION CRITERIA

We included only prospective, randomised and controlled trials with a follow-up time of at least 12 months. Interventions included modifications in surgical technique explicitly to inhibit PCO, modifications in IOL design (material and geometry), implantation of additional devices, and pharmacological therapy, compared to each other, placebo or standard treatment.

DATA COLLECTION AND ANALYSIS

Data were extracted and entered into Review Manager. Visual acuity data, PCO score and YAG capsulotomy rates were compared and a meta-analysis was performed when possible.

MAIN RESULTS

Fifty three studies were included in the review. The review was divided into three parts. (1) Influence of IOL optic material on the development of PCO. Compared to other materials, the meta-analysis of the included studies showed a significantly higher PCO score (overall effect: 12.39 (95% confidence interval: 9.82 to 14.95), scale 0 to 100) and YAG rate (odds ratio: 8.37 (3.74 to 20.36)) only in hydrogel IOLs. (2) Influence of IOL optic design on the development of PCO. There was a significantly lower PCO score (-8.65 (-10.72 to -6.59), scale 0 to 100) and YAG rate (0.19 (0.11 to 0.35)) in sharp edged than in round edged IOLs, however, not between 1-piece and 3-piece IOLs. (3) Influence of surgical technique and drugs on the development of PCO. There was no significant difference between different types of intra-/postoperative anti-inflammatory treatment except for treatment with an immunotoxin (MDX-A) leading to a significantly lower PCO rate.

AUTHORS' CONCLUSIONS

Due to the highly significant difference between round and sharp edge IOL optics, IOLs with sharp (posterior) optic edges should be preferred. There is no clear difference between optic materials, except for hydrogel IOLs, that showed more PCO than the other materials. The choice of postoperative anti-inflammatory treatment does not seem to influence PCO development.

Long-term results of sealed capsule irrigation using distilled water to prevent posterior capsule opacification: a prospective clinical randomised trial

BACKGROUND

We investigated long-term safety and efficacy of sealed capsule irrigation (SCI) during cataract surgery to prevent posterior capsule opacification (PCO).

METHODS

One eye of each of 17 patients (mean age: 70.1+/-9.7 years) who presented with bilateral cataracts was randomly chosen for SCI treatment. After phacoemulsification, the capsular bag was vacuum sealed with the PerfectCapsule device (Milvella) followed by SCI using distilled water for two minutes. No vacuum loss occurred during irrigation. Each patient's fellow eye served as a control. One hydrophilic acrylic intraocular lens model was implanted in all eyes. Five patients had to be excluded due to deep anterior chamber, small pupil or unilateral surgery. Follow-up examinations took place one day and one, three, six, 12 and 24 months after surgery. We evaluated safety parameters, anterior capsule (AC) overlapping and PCO.

RESULTS

Postoperatively, mean best corrected visual acuity, pachymetry, endothelial cell count, intraocular pressure, AC overlapping and PCO showed no statistically significant difference between SCI and the control group (p>0.05, Wilcoxon test).

CONCLUSION

SCI is a safe procedure and enables the specific pharmacological targeting of lens epithelial cells inside the capsular bag. Using distilled water, however, it is not possible to reduce PCO development significantly. Thus, alternative substances should be evaluated.

Effect of diclofenac on prevention of posterior capsule opacification in human eyes

BACKGROUND

Diclofenac sodium has been demonstrated to be effective in preventing proliferation of lens epithelial cells both in vitro and in animal studies. The effects of diclofenac sodium given during the hydrodissection stage of phacoemulsification surgery on posterior capsule opacification (PCO) were investigated.

METHODS

Eleven patients undergoing phacoemulsification in both eyes were included. Patients with pseudoexfoliation, uveitis, and diabetes were excluded. Hydrodissection was done with only balanced salt solution in the first eyes. In the fellow eyes, 0.25 mg/mL diclofenac was given with hydrodissection. The same type of intraocular lens was implanted in both eyes of each patient. Follow-up was 21.8 (SD 3.5) months in the diclofenac group and 22.9 (3.7) months in the control group. PCO was evaluated clinically by dividing the posterior capsule into 24 zones. Mann-Whitney U test was used for statistical analysis.

RESULTS

There were no statistically significant differences of age, diameter of capsulorhexis, pupillary width, visual acuity, intraocular pressure, or length of follow-up between groups. PCO score was 0.49 (SD 0.21) in eyes receiving diclofenac and 0.73 (0.23) in the contralateral fellow eyes. The difference was not statistically significant (p=0.053).

INTERPRETATION

Diclofenac sodium given by hydrodissection in phacoemulsification decreased, but did not significantly prevent, the development of PCO.

Effect of topical prednisolone and diclofenac on the short-term change in morphology of posterior capsular opacification

PURPOSE

To observe and document the effect of steroidal and nonsteroidal antiinflammatory treatment on the formation of Elschnig pearls.

DESIGN

A prospective, randomized, double blinded, placebo controlled, two-way-cross-over study.

METHODS

Thirty-nine eyes of 32 patients with pronounced, regeneratory posterior capsule opacification (PCO) were included. The patients were treated topically with prednisolone and diclofenac (verum) or with lubricating eye drops (placebo) four times daily for one week. After a wash-out period of two weeks the patients received the contrary treatment also four times daily for one week. Digital retroillumination images were taken at day one, three, five, eight, and 15 of each medication period. The changes in the size of 4,675 Elschnig pearls were analyzed.

RESULTS

The mean cumulative area of all marked pearls/eye and follow-up was 1.2 mm(2) (range: 0.1 mm(2) to 3.2 mm(2)). The mean pearl size was 12,809 microm(2) (range: 60 microm(2) to 1.08 x 10(6) microm(2)). Between the follow-up examinations, 1,274 pearls disappeared (mean: 33 pearls/eye, range: five to 69 pearls; 27%) and 777 newly formed pearls appeared (mean: 20 pearls/eye, range: three to 53 pearls; 20%). There was no statistically significant difference in pearl size change and in number of disappeared and newly appeared pearls between the verum and the placebo treatments.

CONCLUSIONS

Topical prednisolone and diclofenac do not influence the short-term change of Elschnig pearls. Elschnig pearls disappear and appear within days. The degree of progression and regression varies greatly among eyes.

Differing effects of dexamethasone and diclofenac on posterior capsule opacification-like changes in a rat lens explant model

Posterior capsular opacification (PCO) arises from lens cells that remain associated with the lens capsule after cataract surgery and subsequently become abnormal, proliferate and migrate into the visual pathway. In this study, a rat lens explant model was used to assess the effects of the prototype steroidal and non-steroidal anti-inflammatory drugs, dexamethasone (DEX) and diclofenac (DIC), on epithelial cells undergoing PCO-like changes. Such drugs are widely used at the time of cataract surgery. TGFbeta2 and FGF-2 were added sequentially and explants were cultured for up to 30 days, with or without addition of DEX or DIC at a clinically relevant concentration. Without DEX or DIC, explants became multilayered and cells tended to retract into PCO-like plaques. Inclusion of DEX, but not DIC, resulted in transient formation of needle-like cells, enhanced cell coverage, and the retention a monolayer of migratory cells surrounding PCO-like plaques. With or without drug addition, most cells became aberrant, as indicated by loss of Pax6 expression and the presence of PCO markers alpha-smooth muscle actin and type I collagen; however, DEX and DIC both strongly enhanced type I collagen accumulation. Furthermore, DEX enhanced cell coverage in explants treated with TGFbeta alone. Thus the behaviour of lens cells was significantly and differentially affected by the presence of DEX and DIC, highlighting the possibility that drugs used to control inflammation after cataract surgery, and the clinician's choice of drugs, may influence PCO development.