Anti-inflammatory Medication After Cataract Surgery and Posterior Capsular Opacification

Effect of surface-modified intraocular lenses on long-term postoperative inhibition of posterior capsule opacification

We compared the posterior capsule opacification incidences at 5 years postoperatively and the neodymium-yttrium-aluminum-garnet capsulotomy rates at 10 years postoperatively for two types of intraocular lenses with different optical properties and shapes. This randomized, controlled, prospective, single-blinded study with intra-individual comparisons was conducted between July 21, 2009, and August 31, 2011, at the Dokkyo Medical University Hospital, Tochigi, Japan. Thirty patients (60 eyes) underwent bilateral cataract surgery and received a XY1 intraocular lens in one eye and a FY-60AD intraocular lens in the other. Both intraocular lenses are acrylic and manufactured by HOYA. The XY1 lens is a single-piece, tinted intraocular lens featuring an ultraviolet/ozone treatment on the posterior surface of the lens optic, aimed at enhancing posterior capsule adhesion to prevent posterior capsule opacification. Conversely, the FY-60AD is a tinted intraocular lens with modified polymethylmethacrylate C-loops and no ultraviolet/ozone treatment of the optic. Scheimpflug images were taken using EAS-1000 (NIDEK Co., Ltd., Aichi, Japan), and the scattered light intensity (computer compatible tape) on the posterior surface of the intraocular lens was calculated and evaluated as the posterior capsule opacification. The scattered light values of the XY1 and FY-60AD groups were 6.50 ± 5.69 and 11.64 ± 5.30 computer compatible tape, respectively, at 5 years postoperatively. The cumulative survival incidence after neodymium-yttrium-aluminum-garnet laser capsulotomy was 74.8 % in the XY1 group and 13.8 % in the FY-60AD group at 10 years postoperatively. The surface-modified intraocular lens XY1 reduced the incidence of posterior capsule opacification even 10 years after surgery. Surface modification to increase the adhesion between the intraocular lens and the capsule effectively prevents posterior capsule opacification.

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.

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.

Photo-controllable drug releasing bulk polyacrylic intraocular lens material for safer posterior capsular opacification prevention

Posterior capsular opacification (PCO) is the most common complication that occurs after intraocular lens (IOL) implantation in cataract therapy. In recent years, IOLs have been developed as drug delivery platforms, but concerns over the safety of uncontrolled proliferative drug release have arisen. Therefore, a controlled drug release strategy is needed for safer PCO prevention. In this study, a new monomer contained coumarin group was introduced in material preparation, and poly(ethylene glycol phenyl ether methacrylate-co-2-(2-ethoxyethoxy) ethyl acrylate-co-7-(2-methacryloyloxyethoxy)-4-methylcoumarin) (PEEC) acrylic IOL materials were synthesized. The antiproliferative drug 5-fluorouracil (5-FU) could be chemically grafted to the PEEC IOL materials easily via a light induced [2 + 2] cycloaddition reaction with the coumarin group, getting drug-loaded IOL (PEEC@5-FU IOL). The PEEC@5-FU IOL exhibited excellent optical and mechanical properties and biocompatibility. More importantly, the loaded 5-FU could be easily controlled from release by light irradiation via photo-dissociation of the cyclobutane ring that was obtained by the [2 + 2] cycloaddition reaction of 5-FU and coumarin. The in vitro and in vivo experiments demonstrated that such photo-controllable drug release IOL could effectively prevent PCO after implantation in a safe way.

Development and Validation of a Prediction Model for Nd:YAG Laser Capsulotomy: A Retrospective Cohort Study of 9768 eyes

INTRODUCTION

Posterior capsular opacification (PCO) is the most common complication of cataract surgery. In this study, we develop a model to quantitatively predict the probability of Nd:YAG laser capsulotomy for vision-threatening PCO to improve the life quality of postoperative patients.

METHODS

A registry analysis of cataract procedures performed between the years 2010 and 2021. Following the screening of 16,802 patients (25,883 eyes), 9768 patients (eyes) were enrolled. The cohort was randomly divided into two groups: training (n = 6838) and validation (n = 2930). To identify relevant risk factors, univariate, multivariate, and Least Absolute Shrinkage and Selection Operator (LASSO) algorithm Cox regression analysis were employed, and a nomogram was created to demonstrate the prediction result.

RESULTS

At 5 years, the overall cumulative incidence of Nd:YAG laser capsulotomy was 12.0% (1169/9768). The following variables were included in the prediction model: sex [hazard ratio (HR) = 1.53, 95% CI 1.32-1.76], age (HR = 0.71, 95% CI 0.56-0.88), intraocular lens (IOL) material (HR = 2.65, 95% CI 2.17-3.24), high myopia (HR = 2.28, 95% CI 1.90-2.75), and fibrinogen (HR = 0.79, 95% CI 0.72-0.88). In the validation cohort, the area under the curve (AUC) of 1-, 3-, and 5-year predictions for Nd:YAG laser capsulotomy were 0.702, 0.691, and 0.688, respectively. For a subgroup of patients with high myopia, the protective effect of hydrophobic IOL disappeared (HR = 0.68, 95% CI 0.51-1.12, P = 0.127).

CONCLUSION

This model could predict the probability of Nd:YAG laser capsulotomy for vision-threatening PCO after cataract surgery by taking into account factors such as age, gender, IOL material, high myopia, and fibrinogen. Meanwhile, implantation of a hydrophobic IOL in individuals with high myopia did not demonstrate a protective impact against vision-threatening PCO.

The Effect of Blue-Light Filtering Intraocular Lenses on the Development and Progression of Glaucoma

PRCIS

Among patients who underwent uneventful cataract surgery, an advantage was seen to blue-light filtering (BLF) intraocular lenses (IOLs) in terms of glaucoma-free survival and glaucoma procedure-free survival. Among patients with preexisting glaucoma, no advantage was seen.

PURPOSE

To assess the effect of BLF IOLs on the development and progression of glaucoma after cataract surgery.

PATIENTS AND METHODS

A retrospective cohort study of patients who underwent uneventful cataract surgery between 2007 and 2018 at Kymenlaakso Central Hospital, Finland. Survival analyses for the overall risk of developing glaucoma or undergoing glaucoma procedures were assessed between patients who received a BLF IOL (SN60WF) and a non-BLF IOL (ZA9003 and ZCB00). A separate analysis was performed on patients with preexisting glaucoma.

RESULTS

Included 11,028 eyes of 11,028 patients with a mean age of 75 ± 9 years (62% females). The BLF IOL was used in 5188 eyes (47%) and the non-BLF IOL in 5840 eyes (53%). During the follow-up (mean: 55 ± 34 mo), 316 cases of glaucoma were diagnosed. Glaucoma-free survival rates showed an advantage to the BLF IOL ( P = 0.036). In a Cox regression analysis controlling for age and sex the use of a BLF IOL was again associated with a lower ratio of glaucoma development (hazard ratio:0.778; 95% CI: 0.621-0.975). Furthermore, glaucoma procedure-free survival analysis revealed an advantage to the BLF IOL (hazard ratio:0.616; 95% CI: 0.406-0.935). Among 662 cases, which already had glaucoma at the time of surgery, no significant differences were seen in any outcome.

CONCLUSIONS

Among a large cohort of patients who underwent cataract surgery, the use of BLF IOLs was associated with favorable glaucoma outcomes compared with the use of non-BLF IOLs. Among patients with preexisting glaucoma, no significant advantage was seen.

Cascade reaction triggering and photothermal AuNPs@MIL MOFs doped intraocular lens for enhanced posterior capsular opacification prevention

Posterior capsular opacification (PCO) is the most common complication after cataract surgery. Present strategies can't meet the clinical needs of long-term prevention. This research reports a novel intraocular lens (IOL) bulk material with high biocompatibility and synergistic therapy. Gold nanoparticles (AuNPs) doped MIL-101-NH₂ metal-organic frameworks (MOFs) (AuNPs@MIL) was firstly fabricated via in situ reductions. Then the functionalized MOFs were uniformly mixed with glycidyl methacrylate (GMA) and 2-(2-ethoxyethoxy) ethyl acrylate (EA) to form the nanoparticle doped polymer (AuNPs@MIL-PGE), and which was used to fabricate IOL bulk materials. The materials' optical and mechanical properties with different mass contents of nanoparticles are investigated. Such bulk functionalized IOL material could efficiently remove residual human lens epithelial cells (HLECs) in the capsular bag in the short term, and can prevent PCO on demand in the long run by near-infrared illumination (NIR) action. In vivo and in vitro experiments demonstrate the biosafety of the material. The AuNPs@MIL-PGE exhibits excellent photothermal effects, which could inhibit cell proliferation under NIR and doesn't cause pathological effects on the surrounding tissues. Such functionalized IOL can not only avoid the side effects of the antiproliferative drugs but also realize the enhanced PCO prevention in clinical practice.

Nd:YAG capsulotomy incidence associated with five different single-piece monofocal intraocular lenses: a 3-year Spanish real-world evidence study of 8293 eyes

OBJECTIVES

To investigate the associations between different single-piece monofocal intraocular lenses (IOLs) and neodymium-doped yttrium aluminum garnet laser (Nd:YAG) capsulotomy incidence 3 years after cataract surgery in a Spanish cohort.

METHODS

This is a longitudinal retrospective cohort study. Data were extracted from the electronic medical records of two large regional hospitals in Spain. Patients aged ≥65 years receiving cataract surgery with placement of five different IOLs and with ≥6 months of baseline data were included. We report the Nd:YAG capsulotomy incidence 3 years post cataract surgery, and the survival plot over the 3 years of follow-up time. The associated adjusted (age, gender, and diabetic retinopathy) multivariate analysis with odds ratios (ORs) and 95% CIs is also presented.

RESULTS

The cohort (53% female, mean age 75 ± 5.9 years) included 14,519 eyes (Alcon AcrySof = 2968, AJL LLASY60 = 1776, Medicontur Bi-flex = 5176, Zeiss Asphina = 4478, and IOL Tech Stabibag = 121). Of these, 8293 were retained until 3-year follow-up. At 3 years after cataract surgery, the Nd:YAG capsulotomy incidence was 5% for Alcon AcrySof, while it ranged from 21.2% to 31.1% for the other IOLs (p < 0.0001 for each comparison). The odds for Nd:YAG capsulotomy were significantly higher (p < 0.0001) for other IOLs compared with those of Alcon AcrySof (ORs = 8.85, 5.86, 5.74, 5.21 for AJL LLASY60, Medicontur Bi-flex, IOL Tech Stabibag, and Zeiss Asphina, respectively).

CONCLUSIONS

The lower Nd:YAG capsulotomy rates for Alcon AcrySof IOLs compared to the other IOLs support the importance of lens choice in reducing patient burden and treatment costs.

Observation of Cyclosporin A: Sustained Release Intraocular Lens Implantation in Rabbit Eyes

PURPOSE

To observe the performance of cyclosporine A (CsA)-loaded intraocular lens (IOLs) implanted into rabbit eyes.

METHODS

To prepare a PLGA-based CsA-sustained release IOLs and study the in vitro drug release. Forty-two New Zealand white rabbits were randomly and equally divided into three groups, and all right eyes underwent phacoemulsification. In group A, a common polymethylmethacrylate (PMMA) IOLs was implanted, while polylactide-glycoli acid (PLGA-loaded)-PMMA-IOLs was implanted in group B, and CsA-PLGA-PMMA-IOLs was implanted in group C. All experimental eyes were examined by slit-lamp microscopy. In addition, fundoscopy and the number of corneal endothelial cells, anterior chamber flare grading, and the number of aqueous humor cells were assessed at different time points post-surgery. The wet lens capsule was weighed and histological examination was performed 6 months post-operation.

RESULTS

In the early post-operative period, the inflammatory reaction of anterior chamber in groups A and B were more severe than group C. The initial appearance of PCO in group C was much later than the other two groups (F = 68.91; p = 0.000), and PCO grade in group C was much lower than the other two groups (χ² = 36.07; p = 0.000). The mean weights of wet lens capsules in groups A and B were significantly heavier than group C (F = 134.88; p = 0.00). Histological observation showed no obvious toxic reaction in the intraocular tissues of the CsA-PLGA-PMMA-IOLs group, and the proliferation and accumulation of lens epithelial cells in groups A and B were greater than in group C.

CONCLUSION

CsA-sustained release IOLs can effectively prevent PCO in rabbit eyes without defined intraocular toxicity.

Design of foldable, responsively drug-eluting polyacrylic intraocular lens bulk materials for prevention of postoperative complications

Posterior capsular opacification (PCO), resulting from undesired intracapsular cell proliferation, is the most common complication of intraocular lens (IOL) implantation after cataract surgery. In recent years, IOLs have been developed into a drug delivery platform. Compared with traditional eye drops, drug-loaded IOLs have the characteristics of independent patient compliance and no other operation except surgical implantation. In this work, a series of poly(glycidyl methacrylate-co-2-(2-ethoxyethoxy)ethyl acrylate) (PGE) acrylic intraocular lens materials were synthesized as drug delivery platforms. The PGE synthesized with 10% crosslinking agent has excellent optical, foldable, and thermomechanical properties. An aldehyde group was subsequently introduced into the PGE chains, and an antiproliferative drug (doxorubicin) was immobilized onto the PGE chains via an H⁺-sensitive imine bond. The IOL exhibits H⁺-dependent Dox release behavior in a simulated pathological environment. The in vitro and in vivo systematical evaluations indicate that such a responsively drug-eluting PGE IOL can effectively prevent PCO.

Advancements in Postoperative Care after Cataract Surgery

Cataract surgery is one of the most frequently performed surgical procedures in many countries [...].

Modeling the Effects of Disease, Drug Properties, and Material on Drug Transport From Intraocular Lenses

Purpose

Surgically implanted intraocular lenses (IOLs) may be used as drug-delivery devices, but their effectiveness is not well defined. Computational fluid dynamics models were developed to investigate the capability of IOLs to release drugs at therapeutic concentrations.

Methods

Models were generated using COMSOL Multiphysics. Primary open-angle glaucoma (POAG) and wet age-related macular degeneration (AMD) were simulated by reducing aqueous vein and choroidal blood flow, respectively. Release of dexamethasone, ganciclovir, or dextran was studied using common IOL materials, polydimethylsiloxane (PDMS) and poly(2-hydroxyethyl methacrylate) (PHEMA).

Results

Drug clearance proceeds mainly through choroidal blood flow. When fully constricted, maximum concentration at the choroid (Cmax) values increased by 32.4% to 39,800%. Compared to dexamethasone, Cmax in different tissues decreased by 6.07% to 96.0% for ganciclovir and dextran, and clearance rates decreased by 16% to 69% for ganciclovir and by 92% to 100% for dextran. Using PDMS as the IOL reduced clearance rates by 91.3% to 94.6% compared to PHEMA.

Conclusions

In diseased eyes, drugs accumulate mainly in posterior tissue; thus, choroidal drug toxicity must be assessed prior to IOL implantation in POAG and AMD patients. Moreover, drug properties modulated concentration profiles in all ocular segments. The hydrophobic small-molecule dexamethasone attained the highest concentrations and cleared the fastest, whereas hydrophilic macromolecular dextran attained the lowest concentrations and cleared the slowest. Furthermore, high concentrations were achieved quickly following release from PHEMA, whereas PDMS allowed for sustained release.

Translational Relevance

In silico results can guide scientists and clinicians regarding important physiological and chemical factors that modulate tissue drug concentrations from drug-eluting IOLs.

Dynamic changes of Elschnig pearls posterior capsule opacification

An adolescent female with underlying bilateral pseudophakia and idiopathic intermediate uveitis had reduced visual acuity due to posterior capsule opacification (PCO). The rapid progression and different morphological formations of Elschnig pearls were not influenced by the uveitis and immunosuppressive treatment. No capsulotomy was performed, and the PCO regressed spontaneously over time.

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.

Effect of cataract surgery on wet age-related macular degeneration activity

BACKGROUND

Wet age-related macular degeneration (AMD) and age-related cataract are often coexisting causes of visual impairment. Yet, the timing of cataract surgery in wet AMD patients is controversial.

METHODS

One hundred and eleven eyes of 111 patients with wet AMD underwent cataract surgery at Helsinki University Hospital in Finland during 2014-2018. Best-corrected visual acuity and central subfield macular thickness (CSMT) were analysed at the time of wet AMD diagnosis, at the last recording prior to cataract surgery and at the first recording and at 1 year after surgery. The cumulative number of antivascular endothelial growth factor (anti-VEGF) injections at surgery, systemic and topical medication and postoperative anti-VEGF burden were recorded.

RESULTS

Mean age was 78.9 ± 5.6 years at the time of surgery. Central subfield macular thickness (CSMT) significantly decreased (280.1 ± 75.0 µm preoperatively to 268.6 ± 67.6 µm at the first postoperative recording, p = 0.001, and to 265.9 ± 67.9 µm at 1 year, p = 0.003), visual acuity improved (0.70 ± 0.46 logMAR units preoperatively to 0.39 ± 0.40 at the first postoperative recording, and to 0.33 ± 0.34 at 1 year, p < 0.001 for both) and anti-VEGF treatment intervals lengthened despite the surgery (6.53 ± 2.08 weeks prior to surgery to 7.03 ± 2.23 weeks at 1 year, p = 0.246, and to 7.05 ± 2.57 weeks at the last documented visit, p = 0.035). A CSMT increase of over 30% from the preoperative values was seen in only one case (1 out of 111 eyes, 0.9%). Macular status at surgery, wet AMD subtype, comorbidity of type II diabetes, systemic drugs and topical anti-inflammatory medication were not associated with macular changes nor with treatment intervals after surgery. The cumulative number of anti-VEGF injections correlated neither with CSMT change postoperatively (r = -0.051, p = 0.619) nor with CSMT change at 1 year (r = 0.091, p = 0.426).

CONCLUSION

Satisfactory visual outcomes and controlled disease activity were seen in patients with wet AMD undergoing cataract surgery. We found no evidence to support delaying surgery in patients who require it.

Nd:YAG Capsulotomy Rates with Two Multifocal Intraocular Lenses

Purpose

To investigate the incidence of Nd:YAG capsulotomy after implantation of two types of multifocal intraocular lenses (MIOLs).

Methods

This retrospective analysis included patients who had undergone cataract extraction and implanted diffractive MIOL (Acri. LISA tri 839M) or asymmetric refractive MIOL (SBL-3) from May 2016 to September 2018. They were followed up for at least 3 years. During the follow-up period, the relevant data of patients were kept by special person in the hospital. The rates of Nd:YAG capsulotomy and the Kaplan-Meier survival curve were used to analyze the two groups.

Results

The Asymmetric Refractive MIOL group was comprised of 98 patients (121 eyes), while the Diffractive MIOL group was comprised of 99 patients (120 eyes). There were no significant differences in age, sex, or IOL power between the two groups. The Nd:YAG rate of the asymmetric refractive MIOL group and the diffractive MIOL group was 3.3% and 7.5% respectively (P = 0.15) in the first year, 14.88% and 22.5% respectively (P = 0.129) in the second year, and 21.49% and 34.17% respectively (P = 0.028) in the third year. In the first 7 months of follow-up, the two groups showed the same performance in the Nd:YAG rate. After that, there was a difference between the two groups, and the difference gradually increased. Until the 27th month of follow-up, the difference was significant (P < 0.05). What is more, there were significant differences in survival (without Nd:YAG capsulotomy)/failure (with Nd:YAG capsulotomy) functions (P = 0.0035).

Conclusion

The incidence of Nd:YAG laser capsulotomy in patients with diffractive MIOLs was higher than that in patients with asymmetric refractive MIOLs.

Anti-inflammatory Pharmacotherapy for the Prevention of Cystoid Macular Edema After Cataract Surgery

PURPOSE

To elucidate strategies for and controversies surrounding the use of anti-inflammatory medications after uneventful cataract surgery, with a focus on the prevention of irreversible vision loss due to cystoid macular edema (CME).

DESIGN

Perspective.

METHODS

Expert commentary on the management of inflammation after cataract surgery. Discussion includes combination therapy with corticosteroids and nonsteroidal anti-inflammatory drugs (NSAIDs), dosing strategies, and emerging therapies.

RESULTS

While prescribing both NSAIDs and corticosteroids for cataract surgery is common, these classes have overlapping mechanisms. Combination therapy may speed visual recovery, but there remains little evidence for improved long-term visual outcomes from NSAIDs. The last 2 decades have seen increasing data on potential benefits of pretreatment with NSAIDs 1-3 days prior to cataract surgery. Simultaneously, newly approved "dropless" delivery systems hold promise, and clinical trials are ongoing to assess outcomes of such formulations.

CONCLUSIONS

Optimal pharmacologic treatment for inflammation after cataract surgery remains controversial. A consensus definition for clinically significant CME may facilitate the comparison of anti-inflammatory drugs. And there remains a need for well-designed trials examining both topical and extended-release drug-delivery systems to refine the treatment paradigm.

Immune responses to injury and their links to eye disease

The eye is regarded as an immune privileged site. Since the presence of a vasculature would impair vision, the vasculature of the eye is located outside of the central light path. As a result, many regions of the eye evolved mechanisms to deliver immune cells to sites of dysgenesis, injury, or in response to the many age-related pathologies. While the purpose of these immune responses is reparative or protective, cytokines released by immune cells compromise visual acuity by inducing inflammation and fibrosis. The response to traumatic or pathological injury is distinct in different regions of the eye. Age-related diseases impact both the anterior and posterior segment and lead to reduced quality of life and blindness. Here we focus attention on the role that inflammation and fibrosis play in the progression of age-related pathologies of the cornea and the lens as well as in glaucoma, the formation of epiretinal membranes, and in proliferative vitreoretinopathy.

Relationship Between Prolonged Intraocular Inflammation and Macular Edema After Cataract Surgery

Purpose

To assess whether aqueous flare is related to an increased risk of pseudophakic cystoid macular edema (PCME) following uneventful cataract surgery in nondiabetic and diabetic patients.

Methods

A post hoc analysis of five consecutive randomized clinical trials in the Department of Ophthalmology, Kymenlaakso Central Hospital, Finland. Aqueous flare levels were recorded in 448 eyes of 448 patients before surgery, and after the course of topical anti-inflammatory treatment 28 days and three months after cataract surgery.

Results

Aqueous flare increase of <50%, ≥50%, ≥100%, and ≥200% associated in central subfield macular thickness (CSMT) increase across the groups at 28 days and three months after surgery. Increase of aqueous flare ≥100% compared to those with <100% was associated with increased CSMT (P = 0.022 at 28 days, and P = 0.027 at three months). At three months, macular thickening (at least 10% CSMT increase) was observed in 12.7% compared to 4.6% of eyes when using a cutoff value of 100% increase in aqueous flare (P = 0.033). Although diabetic patients presented higher aqueous flare levels at baseline compared to nondiabetic patients (12.9 ± 11.8 vs. 9.8 ± 8.2 photon units/ms P < 0.001), the postoperative levels illustrated a similar profile in aqueous flare increase between the two groups.

Conclusions

At 28 days, aqueous flare increase was associated with macular thickening. A 100% cutoff value could potentially be used when studying anti-inflammatory efficacy of different treatment protocols. Flare values exceeding this cutoff value could be considered as an indication for extending anti-inflammatory therapy.

Translational Relevance

A 100% increase in aqueous flare at 28 days after cataract surgery from baseline predicted macular thickening up to three months postoperatively. Identifying a correlation between increased aqueous flare levels and pseudophakic cystoid macular edema may allow recognition of the most vulnerable patients, development of prophylactic treatment strategies and reduction of the number and severity of postoperative complications.

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.

Factors Affecting Posterior Capsule Opacification in the Development of Intraocular Lens Materials

Posterior capsule opacification (PCO) is the most common complication arising from the corrective surgery used to treat cataract patients. PCO arises when lens epithelial cells (LEC) residing in the capsular bag post-surgery undergo hyper-proliferation and transdifferentiation into myofibroblasts, migrating from the posterior capsule over the visual axis of the newly implanted intraocular lens (IOL). The developmental pathways underlying PCO are yet to be fully understood and the current literature is contradictory regarding the impact of the recognised risk factors of PCO. The aim of this review is firstly to collate the known biochemical pathways that lead to PCO development, providing an up-to-date chronological overview from surgery to established PCO formation. Secondly, the risk factors of PCO are evaluated, focussing on the impact of IOLs’ properties. Finally, the latest experimental model designs used in PCO research are discussed to demonstrate the ongoing development of clinical PCO models, the efficacy of newly developed IOL technology, and potential therapeutic interventions. This review will contribute to current PCO literature by presenting an updated overview of the known developmental pathways of PCO, an evaluation of the impact of the risk factors underlying its development, and the latest experimental models used to investigate PCO. Furthermore, the review should provide developmental routes for research into the investigation of potential therapeutic interventions and improvements in IOL design in the aid of preventing PCO for new and existing patients.

Posterior capsule opacification: What's in the bag?

Cataract, a clouding of the lens, is the most common cause of blindness in the world. It has a marked impact on the wellbeing and productivity of individuals and has a major economic impact on healthcare providers. The only means of treating cataract is by surgical intervention. A modern cataract operation generates a capsular bag, which comprises a proportion of the anterior capsule and the entire posterior capsule. The bag remains in situ, partitions the aqueous and vitreous humours, and in the majority of cases, houses an intraocular lens (IOL). The production of a capsular bag following surgery permits a free passage of light along the visual axis through the transparent intraocular lens and thin acellular posterior capsule. Lens epithelial cells, however, remain attached to the anterior capsule, and in response to surgical trauma initiate a wound-healing response that ultimately leads to light scatter and a reduction in visual quality known as posterior capsule opacification (PCO). There are two commonly-described forms of PCO: fibrotic and regenerative. Fibrotic PCO follows classically defined fibrotic processes, namely hyperproliferation, matrix contraction, matrix deposition and epithelial cell trans-differentiation to a myofibroblast phenotype. Regenerative PCO is defined by lens fibre cell differentiation events that give rise to Soemmerring's ring and Elschnig's pearls and becomes evident at a later stage than the fibrotic form. Both fibrotic and regenerative forms of PCO contribute to a reduction in visual quality in patients. This review will highlight the wealth of tools available for PCO research, provide insight into our current knowledge of PCO and discuss putative management of PCO from IOL design to pharmacological interventions.