EXPRESSION OF CYCLOOXYGENASE-2 IN CHOROIDAL NEOVASCULAR MEMBRANES FROM AGE-RELATED MACULAR DEGENERATION PATIENTS

Sulforaphane ameliorates amyloid-β-induced inflammatory injury by suppressing the PARP1/SIRT1 pathway in retinal pigment epithelial cells

Age-associated macular degeneration (AMD) is a progressive eye disorder that leads to irreversible impairment of central vision, and effective therapies are lacking. Here, we explore how oligomeric amyloid-β_1-42 can trigger inflammatory injury in retinal pigment epithelial cells and how sulforaphane can mitigate such injury. ARPE-19 retinal pigment epithelial cells expressing low, endogenous, or high levels of poly(ADP-ribose) polymerase (PARP1) were treated with oligomeric amyloid-β_1-42 in the presence or absence of various signaling inhibitors or sulforaphane. Cell viability, apoptosis, inflammatory responses, and activity of the PARP1/Sirtuin (SIRT1) axis were assayed. Treating ARPE-19 cells with oligomeric amyloid-β_1-42 promoted the production of IL-1β, IL-6, IL-8, and TNF-ɑ, which was partially reversed by inhibiting PARP1 and activating SIRT1. PARP1 was found to act upstream of SIRT1, and expression of the two proteins correlated negatively with each other. Sulforaphane also mitigated the injury due to oligomeric amyloid-β_1-42 through a mechanism involving inactivation of the PARP1/SIRT1 pathway. Oligomeric amyloid-β_1-42 can trigger AMD-like injury in retinal pigment epithelium by activating PARP1 and repressing SIRT1. Moreover, sulforaphane can induce cell viability and SIRT1 expression, but reduce cell apoptosis, the activity of caspase-3 or -9, and PARP1 expression in oAβ_1-42-treated cells. However, PARP1 inactivation or SIRT1 activation weaken these effects. In summary, sulforaphane reduces the inflammatory injury induced by oAβ_1-42 in ARPE-19 cell by inactivating the PARP1/SIRT1 pathway. Thus, the compound may be an effective therapy against AMD.

Non-steroidal Anti-inflammatory Drug Use and Risk of Age-Related Macular Degeneration in the California Teachers Study

Purpose

The aim of this study was to examine whether use of regular aspirin and/or other non-steroidal anti-inflammatory drugs (NSAIDs) is associated with the development of age-related macular degeneration (AMD).

Methods

In the California Teachers Study cohort (N = 88,481) we identified diagnoses of AMD up to December 31, 2012 by linkage to statewide hospital discharge records. Aspirin, ibuprofen, other NSAIDs, and acetaminophen use and comprehensive risk factor information were collected via self-administered questionnaires at baseline in 1995–1996 and a follow-up questionnaire in 2005–2006. We employed Cox proportional hazard regression to model AMD risk.

Results

We did not find any associations between AMD and frequency and duration of aspirin or ibuprofen use reported at baseline. In the subsample with more specific information on medication use, we observed a 20% decrease in risk of AMD among low-dose aspirin users (HR 0.81, 95% CI 0.70–0.95) and a 55% decrease among cyclooxygenase-2 (COX-2) inhibitor users (HR 0.45, 95% CI 0.26–0.78) during 6.3 years of average follow-up.

Conclusion

The decrease in risk of intermediate- or late-stage AMD among women who reported regular use of low-dose aspirin or specific COX-2 inhibitors suggests a possible protective role for medications with COX-2 inhibitory properties or aspirin at doses used for cardiovascular disease prevention.

4-(Phenylsulfanyl) Butan-2-One Attenuates the Inflammatory Response Induced by Amyloid-β Oligomers in Retinal Pigment Epithelium Cells

Age-related macular degeneration (AMD) is a progressive eye disease that causes irreversible impairment of central vision, and effective treatment is not yet available. Extracellular accumulation of amyloid-beta (Aβ) in drusen that lie under the retinal pigment epithelium (RPE) has been reported as one of the early signs of AMD and was found in more than 60% of Alzheimer’s disease (AD) patients. Extracellular deposition of Aβ can induce the expression of inflammatory cytokines such as IL-1β, TNF-α, COX-2, and iNOS in RPE cells. Thus, finding a compound that can effectively reduce the inflammatory response may help the treatment of AMD. In this research, we investigated the anti-inflammatory effect of the coral-derived compound 4-(phenylsulfanyl) butan-2-one (4-PSB-2) on Aβ_1-42 oligomer (oAβ_1-42) added to the human adult retinal pigment epithelial cell line (ARPE-19). Our results demonstrated that 4-PSB-2 can decrease the elevated expressions of TNF-α, COX-2, and iNOS via NF-κB signaling in ARPE-19 cells treated with oAβ_1-42 without causing any cytotoxicity or notable side effects. This study suggests that 4-PSB-2 is a promising drug candidate for attenuation of AMD.

Risk of age-related macular degeneration in aspirin users and non-aspirin users: A population-based cohort study in Taiwan

BACKGROUND

The association between cardioprotective aspirin and risk of age-related macular degeneration (AMD) is still controversial up to date. We aimed to analyze the risk of AMD between aspirin users and non-aspirin users.

METHOD

This was a retrospective cohort study by using claims data from the National Health Insurance Research Database. Patients aged more than 45 years old who initiated aspirin during 2002 to 2012 were followed till 2013. We first selected an age and sex-matched cohort, then identified aspirin users and non-aspirin users as propensity score-matched cohort. Cox proportional hazard regression model was applied to compare their hazards and 95% confidence intervals. Incidence of newly developed AMD, neovascular AMD, and other-AMD was calculated.

RESULTS

We identified 204 085 regular aspirin users and 478 048 non-aspirin users from our datasets. The univariate HR was 2.85 (95% CI, 2.75-2.96), and the multivariate HR was 2.54 (95% CI, 2.44-2.65). In the PS-matched cohort, the HR was 2.38 (95% CI, 2.25-2.52). The incidence of aspirin users for AMD risk was 11.95 per 1000 person-year, while the incidence of non-aspirin users was only 3.92 per 1000 person-year.

CONCLUSION

Patients with regular use of aspirin had higher risk in developing AMD compared to non-aspirin users and suggest to have regular visual acuity and funduscopic examination.

Potential Role of Myeloid-Derived Suppressor Cells (MDSCs) in Age-Related Macular Degeneration (AMD)

Myeloid cells, such as granulocytes/neutrophils and macrophages, have responsibilities that include pathogen destruction, waste material degradation, or antigen presentation upon inflammation. During persistent stress, myeloid cells can remain partially differentiated and adopt immunosuppressive functions. Myeloid-derived suppressor cells (MDSCs) are primarily beneficial upon restoring homeostasis after inflammation. Because of their ability to suppress adaptive immunity, MDSCs can also ameliorate autoimmune diseases and semi-allogenic responses, e.g., in pregnancy or transplantation. However, immunosuppression is not always desirable. In certain conditions, such as cancer or chronically inflamed tissue, MDSCs prevent restorative immune responses and thereby aggravate disease progression. Age-related macular degeneration (AMD) is the most common disease in Western countries that severely threatens the central vision of aged people. The pathogenesis of this multifactorial disease is not fully elucidated, but inflammation is known to participate in both dry and wet AMD. In this paper, we provide an overview about the potential role of MDSCs in the pathogenesis of AMD.

Stability and Ocular Pharmacokinetics of Celecoxib-Loaded Nanoparticles Topical Ophthalmic Formulations

A spontaneous emulsification and/or solvent diffusion method was used for the preparation of celecoxib-loaded nanoparticles (NPs) using polymers, including chitosan (CS), sodium alginate, poly-ε-caprolactone (PCL), poly-l-lactide, and poly-d,l-lactide-co-glycolide. NPs were incorporated into vehicles (eye drops, in situ gelling system, and gel). Formulations were subjected to an accelerated stability study by storing them at elevated temperatures of 30, 35, and 45°C for 6 months. Formulations were evaluated monthly for general appearance, pH, viscosity, particle size, polydispersity index, zeta potential, and drug content. Gels containing CS-NPs and PCL-NPs were selected for an ocular pharmacokinetics study using Sprague-Dawley rats due to their high stability and long shelf lives (24.56 and 33.76 months, respectively). The gel improved NP stability by keeping it inside its network structure, which protected them from aggregation and interacting with water. Our formulations improved celecoxib bioavailability due to their bioadhesivness, thus preventing their rapid removal. Also, NPs acted as drug reservoirs that adhered to eye surface and continuously released the drug. The availability of celecoxib in all eye tissues and its absence in plasma suggests that our formulation could be used for anterior eye disorders and also for treatment of diseases associated with the posterior eye with no systemic side effects.

Fluorocoxib A enables targeted detection of cyclooxygenase-2 in laser-induced choroidal neovascularization

Ocular angiogenesis is a blinding complication of age-related macular degeneration and other retinal vascular diseases. Clinical imaging approaches to detect inflammation prior to the onset of neovascularization in these diseases may enable early detection and timely therapeutic intervention. We demonstrate the feasibility of a previously developed cyclooxygenase-2 (COX-2) targeted molecular imaging probe, fluorocoxib A, for imaging retinal inflammation in a mouse model of laser-induced choroidal neovascularization. This imaging probe exhibited focal accumulation within laser-induced neovascular lesions, with minimal detection in proximal healthy tissue. The selectivity of the probe for COX-2 was validated <italic<in vitro</italic< and by <italic<in vivo</italic< retinal imaging with nontargeted 5-carboxy-X-rhodamine dye, and by blockade of the COX-2 active site with nonfluorescent celecoxib prior to injection of fluorocoxib A. Fluorocoxib A can be utilized for imaging COX-2 expression <italic<in vivo</italic< for further validation as an imaging biomarker in retinal diseases.

The COX-2-Selective Antagonist (NS-398) Inhibits Choroidal Neovascularization and Subretinal Fibrosis

Choroidal neovascularization (CNV) is an important pathologic component of neovascular age-related macular degeneration (AMD), and CNV lesions later develop into fibrous scars, which contribute to the loss of central vision. Nowadays, the precise molecular and cellular mechanisms underlying CNV and subretinal fibrosis have yet to be fully elucidated. Cyclooxygenase-2 (COX-2) has previously been implicated in angiogenesis and fibrosis. However, the role of COX-2 in the pathogenesis of CNV and subretinal fibrosis is poorly understood. The present study reveals several important findings concerning the relationship of COX-2 signaling with CNV and subretinal fibrosis. Experimental CNV lesions were attenuated by the administration of NS-398, a COX-2-selective antagonist. NS-398-induced CNV suppression was found to be mediated by the attenuation of macrophage infiltration and down-regulation of VEGF in the retinal pigment epithelium-choroid complex. Additionally, NS-398 attenuated subretinal fibrosis, in an experimental model of subretinal scarring observed in neovascular AMD, by down-regulation of TGF-β2 in the retinal pigment epithelium-choroid complex. Moreover, we cultured mouse RPE cells and found that NS-398 decreased the secretion of VEGF and TGF-β2 in mouse RPE cells. The results of the present study provide new findings regarding the molecular basis of CNV and subretinal fibrosis, and provide a proof-of-concept approach for the efficacy of COX-2 inhibition in treating subretinal fibrosis.

Protective effects of resveratrol against UVA-induced damage in ARPE19 cells

Ultraviolet radiation, especially UVA, can penetrate the lens, reach the retina, and induce oxidative stress to retinal pigment epithelial (RPE) cells. Even though it is weakly absorbed by protein and DNA, it may trigger the production of reactive oxygen species (ROS) and generate oxidative injury; oxidative injury to the retinal pigment epithelium has been implicated to play a contributory role in age-related macular degeneration (AMD). Studies showed that resveratrol, an abundant and active component of red grapes, can protect several cell types from oxidative stress. In this study, adult RPE cells being treated with different concentrations of resveratrol were used to evaluate the protective effect of resveratrol on RPE cells against UVA-induced damage. Cell viability assay showed that resveratrol reduced the UVA-induced decrease in RPE cell viability. Through flow cytometry analysis, we found that the generation of intracellular H₂O₂ induced by UVA irradiation in RPE cells could be suppressed by resveratrol in a concentration-dependent manner. Results of Western blot analysis demonstrated that resveratrol lowered the activation of UVA-induced extracellular signal-regulated kinase, c-jun-NH₂ terminal kinase and p38 kinase in RPE cells. In addition, there was also a reduction in UVA-induced cyclooxygenase-2 (COX-2) expression in RPE cells pretreated with resveratrol. Our observations suggest that resveratrol is effective in preventing RPE cells from being damaged by UVA radiation, and is worth considering for further development as a chemoprotective agent for the prevention of early AMD.

The safety, pharmacokinetics, and efficacy of intraocular celecoxib

PURPOSE

To determine safety, pharmacokinetics, and anti-inflammatory effects of intraocular celecoxib.

METHODS

The right eye of animals was injected with 1.5, 3, or 6 mg celecoxib prepared in dimethyl sulfoxide (DMSO). Left eyes served as controls and received 0.1 mL DMSO. Electroretinograms (ERG) were obtained at baseline and at 1, 4, and 12 weeks, and eyes were enucleated afterward for histopathologic analysis. For pharmacokinetics, 3 mg celecoxib was injected, and vitreous and retina/choroid drug levels were then analyzed at specific time points. For efficacy, 1 μg lipopolysaccharide was injected to induce inflammation; the right eye was then injected with 3 mg celecoxib (six eyes) or 2 mg triamcinolone acetonide (six eyes) and the left eye with saline. Twenty-four hours later, aqueous fluid was removed, and total leukocyte concentration and prostaglandin E2 (PGE2) concentration were determined.

RESULTS

Histologic and ERG studies demonstrated no signs of retinal or optic nerve toxicity. After a single 3-mg injection, vitreous (0.06 μg/mL) and retina/choroid (132.31 μg/g) celecoxib concentrations at 8 weeks exceeded median inhibitory concentration. Treatment with celecoxib and triamcinolone significantly reduced total leukocyte count by 40% (P = 0.02) and 31% (P = 0.01), respectively. Reduction in PGE2 levels paralleled reduction in leukocyte counts (P < 0.05). There was no increase in intraocular pressure, but cataract formation was observed at higher concentrations.

CONCLUSIONS

Intraocular injection of celecoxib appeared to be nontoxic and demonstrated excellent penetration into the retina/choroid and sustained drug levels out to 8 weeks. Celecoxib demonstrated potent anti-inflammatory effects, but there was an association with cataract formation at higher doses.

Current and investigational pharmacotherapeutic approaches for modulating retinal angiogenesis

Retinal vascular development is a carefully orchestrated developmental process during which retinal and choroidal vasculature form to provide a dual vascular supply to the neurosensory retina and retinal pigment epithelium. The most common causes of vision loss in children and adults involve at least in part perturbation of the normal vascular physiology or development. Vascular endothelial growth factor has emerged as a key molecular regulator of retinal vascular development as well as retinal and choroidal neovascularization, which underlie the pathophysiology of many retinal diseases. Over the past decade, the advent of injectable pharmacotherapeutic agents into the vitreous cavity of the eye has revolutionized our management of neovascular age-related macular degeneration and other retinal diseases and has, for the first time, offered an opportunity to improve vision rather than just slow the progression of disease processes. The transient duration of these agents, however, requires chronic treatment with repeated intraocular injections and significant treatment burden for patients and the healthcare system. Novel treatments modulating retinal angiogenesis offer the promise of improved efficacy, decreased treatment burden and improved cost-effectiveness.

Topical nonsteroidal anti-inflammatory drugs for macular edema

Nonsteroidal anti-inflammatory drugs (NSAIDs) are nowadays widely used in ophthalmology to reduce eye inflammation, pain, and cystoid macular edema associated with cataract surgery. Recently, new topical NSAIDs have been approved for topical ophthalmic use, allowing for greater drug penetration into the vitreous. Hence, new therapeutic effects can be achieved, such as reduction of exudation secondary to age-related macular degeneration or diabetic maculopathy. We provide an updated review on the clinical use of NSAIDs for retinal diseases, with a focus on the potential future applications.

Nonsteroidal anti-inflammatory drugs for retinal disease

Nonsteroidal anti-inflammatory drugs (NSAIDs) are used extensively in ophthalmology for pain and photophobia after photorefractive surgery and to reduce miosis, inflammation, and cystoid macular edema following cataract surgery. In recent years, the US Food and Drug Administration has approved new topical NSAIDs and previously approved NSAIDs have been reformulated. These changes may allow for greater drug penetration into the retina and thereby offer additional therapeutic advantages. For example, therapeutic effects on diabetic retinopathy and age-related macular degeneration may now be achievable. We provide an updated review on the scientific rationale and clinical use of NSAIDs for retinal disease.

Nanoparticle-based topical ophthalmic formulations for sustained celecoxib release

Celecoxib-loaded NPs were prepared from biodegradable polymers such as poly-ε-caprolactone (PCL), poly(L-lactide) (PLA), and poly(D,L-lactide-co-glycolide) (PLGA) by spontaneous emulsification solvent diffusion method. Different concentrations of polymers, emulsifier, and cosurfactants were used for formulation optimization. Nanoparticles (NPs) were characterized regarding their particle size, PDI, zeta potential, shape, morphology, and drug content. Celecoxib-loaded NPs were incorporated into eye drops, in situ gelling system, and gel and characterized regarding their pH, viscosity, uniformity of drug content, in vitro release, and cytotoxicity. The results of optimized celecoxib-loaded PCL-, PLGA-, and PLA-NPs, respectively, are particle size 119 ± 4, 126.67 ± 7.08, and 135.33 ± 4.15 nm; zeta potential -22.43 ± 2.91, -25.46 ± 2.35, and -31.81 ± 2.54 mV; and encapsulation efficiency 93.44 ± 3.6%, 86.00 ± 1.67%, and 79.04 ± 2.6%. TEM analyses revealed that NPs have spherical shapes with dense core and distinct coat. Formulations possessed uniform drug content with pH and viscosity compatible with the eye. Formulations showed sustained release without any burst effect with the Higuchi non-fickian diffusion mechanism. Cytotoxicity studies revealed that all formulations are nontoxic. Our formulations provide a great deal of flexibility to formulation scientist whereby sizes and zeta potentials of our NPs can be tuned to suit the need using scalable and robust methodologies. These formulations can thus serve as a potential drug delivery system for both anterior and posterior eye diseases.

Progression of macular atrophy after PDT combined with the COX-2 inhibitor Nabumetone in the treatment of neovascular ARMD

AIM

To evaluate photodynamic therapy (PDT) combined with the preferential the cyclooxygenase-2 (COX-2) inhibitor, nabumetone in the treatment of the neovascular age-related macular degeneration (ARMD).

METHODS

A prospective, double-blind, randomized study on 60 patients with subfoveal CNV secondary to ARMD without any previous treatment. Patients were divided into a nabumetone or placebo group. The main endpoints were the change of best-corrected visual acuity (BCVA), central macular thickness (CRT) and number of required PDT treatments.

RESULTS

In the nabumetone group, 27 patients (90%) and 28 (93%) in the placebo group completed the follow-up of 12 months. In the nabumetone group, the mean CRT decreased from 332 μm (SD 68 μm) to 220 μm (SD 46 μm). In the placebo group, CRT decreased from 331 μm (SD 72 μm) to 254 μm (SD 61 μm). The mean BCVA was 0.68 log MAR (SD 0.22 log MAR) in the nabumetone group and 0.62 log MAR (SD 0.23 log MAR) in the placebo group at baseline. This stabilised in the placebo group to 0.66 log MAR (SD 0.33) but deteriorated in the nabumetone group to 0.86 log MAR (SD 0.41 log MAR). There was a significant reduction in the number of required PDTs in the nabumetone group, but significant progression of the RPE atrophy area.

CONCLUSION

Combined PDT with oral intake of the COX-2 inhibitor, nabumetone reduced the number of required PDT retreatments, but worsening BCVA caused by macular atrophy progression. Therefore the combination of the PDT with the nabumetone is not recommended.

Critical appraisal of ophthalmic ketorolac in treatment of pain and inflammation following cataract surgery

Background:

The purpose of this review was to provide a critical appraisal of the literature supporting the efficacy of ophthalmic ketorolac (Acuvail^®) in the treatment of pain and inflammation after cataract surgery.

Methods:

Literature search and expert opinion of the authors.

Results:

Recent studies indicate greater intraocular drug levels in the anterior chamber and iris-ciliary body after topical application of Acuvail in comparison with older formulations of ketorolac. A large randomized, multicenter, placebo-controlled study demonstrated significantly less inflammation and pain after cataract surgery using Acuvail.

Conclusion:

Acuvail appears to be effective in reducing post-cataract surgery pain and inflammation.

Reduced choroidal neovascular membrane formation in cyclooxygenase-2 null mice

PURPOSE

To assess the degree of laser-induced choroidal neovascular membrane formation in wild-type (WT) and COX-2 null mice and to measure vascular endothelial growth factor (VEGF), interleukin (IL)-1β, and tumor necrosis factor (TNF)-α levels in the retina and choroid.

METHODS

Four laser burns were placed in each eye of WT and COX-2 null mice to induce choroidal neovascularization. Fluorescein angiography (FA) was performed at 14 days, and retinal pigment epithelium-choroid-sclera (choroidal) flat mounts were prepared. The retina and choroid were isolated from WT and COX-2 null mice at 24, 72, and 168 hours after laser photocoagulation and from unlasered eyes and were tested for VEGF, IL-1β, and TNF-α.

RESULTS

COX-2 null mice demonstrated 58% (P = 0.001) and 48% (P = 0.001) reductions in CNV formation on FA and choroidal flat mounts, respectively, compared with WT mice. For unlasered mice, mean VEGF concentrations in the retina and choroid were 1.2 ± 0.42 pg/mg protein for WT but only 0.42 ± 0.2 pg/mg protein for COX-2 null mice (P < 0.05). After laser photocoagulation, WT mice showed significantly greater VEGF and IL-β expression in the retina and choroid by 168 hours (P < 0.05) and 72 hours (P < 0.05), respectively, compared with COX-2 null mice.

CONCLUSIONS

COX-2 null mice exhibited significantly less choroidal neovascular membrane formation associated with reduced expression of VEGF. The results of this study suggest that COX-2 modulates VEGF expression in CNV and implicates a potential therapeutic role for nonsteroidal anti-inflammatory drugs.

The role of anti-inflammatory agents in age-related macular degeneration (AMD) treatment

Although age-related macular degeneration (AMD) is not a classic inflammatory disease like uveitis, inflammation has been found to have an important role in disease pathogenesis and progression. Innate immunity and autoimmune components, such as complement factors, chemokines, cytokines, macrophages, and ocular microglia, are believed to be heavily involved in AMD development. Targeting these specific inflammatory molecules has recently been explored in an attempt to better understand and treat AMD. Although antivascular endothelial growth factor therapy is the first line of defence against neovascular AMD, anti-inflammatory agents such as corticosteroids, nonsteroidal anti-inflammatory drugs (NSAIDs), immunosuppressive agents (eg, methotrexate and rapamycin), and biologics (eg, infliximab, daclizumab, and complement inhibitors) may provide an adjunct or alternative mechanism to suppress the inflammatory processes driving AMD progression. Further investigation is required to evaluate the long-term safety and efficacy of these drugs for both neovascular and non-neovascular AMD.

Ketorolac inhibits choroidal neovascularization by suppression of retinal VEGF

We assessed the effect of topical ketorolac on laser-induced choroidal neovascularization (CNV), measured retinal PGE(2) and VEGF levels after laser treatment, and determined the effect of ketorolac on PGE(2) and VEGF production. Six laser burns were placed in eyes of rats which then received topical ketorolac 0.4% or artificial tears four times daily until sacrifice. Fluorescein angiography (FA) was performed at 2 and 3 weeks and retinal pigment epithelium-choroid-sclera flat mounts were prepared. The retina and vitreous were isolated at 1, 3, 5, 7, and 14 days after laser treatment and tested for VEGF and PGE(2). Additional animals were lasered and treated with topical ketorolac or artificial tears and tested at 3 and 7 days for retinal and vitreous VEGF and PGE(2.) Ketorolac reduced CNV on FA by 27% at 2 weeks (P<0.001) and 25% at 3 weeks (P<0.001). Baseline retina and vitreous PGE(2) levels were 29.4 μg/g and 16.5 μg/g respectively, and reached 51.2 μg/g and 26.9 μg/g respectively, 24h after laser treatment (P<0.05). Retinal VEGF level was 781pg/g 24h after laser treatment and reached 931pg/g by 7 days (P<0.01). Ketorolac reduced retinal PGE(2) by 35% at 3 days (P<0.05) and 29% at 7 days (P<0.001) and retinal VEGF by 31% at 3 days (P=0.10) and 19% at 7 days (P<0.001). Topical ketorolac inhibited CNV and suppressed retinal PGE(2) and VEGF production.

Nonsteroidal anti-inflammatory drugs in ophthalmology

Nonsteroidal anti-inflammatory drugs (NSAIDs) are increasingly employed in ophthalmology to reduce miosis and inflammation, manage scleritis, and prevent and treat cystoid macular edema associated with cataract surgery. In addition, they may decrease postoperative pain and photophobia associated with refractive surgery and may reduce the itching associated with allergic conjunctivitis. In recent years, the U.S. Food and Drug Administration has approved new topical NSAIDs, and previously approved NSAIDs have been reformulated. These additions and changes result in different pharmacokinetics and dosing intervals, which may offer therapeutic advantages. For example, therapeutic effects on diabetic retinopathy and age-related macular degeneration may now be achievable. We provide an updated review on NSAIDs and a summary of their current uses in ophthalmology with attention to potential future applications.

Cyclo-oxygenase-2 expression in human idiopathic epiretinal membrane

PURPOSE

The purpose of this study was to examine the expression of cyclo-oxygenase (COX)-2 in the idiopathic epiretinal membrane (IERM), inner limiting membrane (ILM), and proliferative diabetic retinopathy membrane.

METHODS

Twenty membranes, consisting of eight IERMs, four ILMs, and eight proliferative diabetic retinopathy membranes, were surgically removed. Formalin-fixed, paraffin-embedded tissue sections were processed for immunohistochemistry using anti-COX-2 antibody. The nuclear density showing the density of cells situated in IERM and ILM specimens was calculated under high-power fields using a light microscope.

RESULTS

The IERM comprised flattened cells with oval nuclei constituting a monolayer. The ILM contained a few cells with abundant collagenous tissues. Neither endothelial nor inflammatory cells were observed in the IERM and ILM. COX-2 immunoreactivity was markedly detected in cells located in the IERM. In contrast, COX-2 immunoreactivity was faintly detected in the ILM. The COX-2-positive rate was 65.4 +/- 15.5% and 34.3 +/- 20.3% in the IERM and ILM, respectively, being significantly higher in the former (P = 0.046). The nuclear density was 39.3 +/- 10.3 and 8.6 +/- 7.2 in the IERM and ILM, respectively, being significantly higher in the former (P = 0.0003). The proliferative diabetic retinopathy membranes consisted of many vascular endothelial and stromal cells. Cytoplasmic immunoreactivity for COX-2 was detected in endothelial and stromal cells in the proliferative diabetic retinopathy membranes.

CONCLUSION

These results suggest that COX-2 plays a potential role in the formation of avascular and vascularized epiretinal membranes if an epiphenomenon of COX-2 expression within these epiretinal membranes has been ruled out in future studies.