The pathogenesis and clinical presentation of macular edema in inflammatory diseases

INTRAVITREAL DEXAMETHASONE FOR THE TREATMENT OF MACULAR EDEMA SECONDARY TO HYDROXYCHLOROQUINE TOXICITY

PURPOSE

Cystoid macular edema is a vision-threatening complication infrequently associated with hydroxychloroquine retinal toxicity. There are limited data on the best treatment for this pathology.

METHODS

A retrospective case series is presented.

RESULTS

In this series, we present three cases of cystoid macular edema in patients with diagnosed hydroxychloroquine maculopathy successfully treated with intravitreal dexamethasone implantation.

CONCLUSION

Minimal literature has been published regarding the best management of cystoid macular edema related to hydroxychloroquine toxicity. Our case series suggests a possible new agent in the treatment of this rare occurrence.

Complications of pupil expansion devices: a large real-world study

Purpose

To assess the risk for uveitis, pseudophakic cystoid macular edema (PCME), and posterior capsular opacification (PCO) associated with the use of pupil expansion devices in cataract surgery.

Design

A retrospective comparative cohort study.

Participants

Patients who underwent routine cataract surgery with and without pupil expansion devices at the Department of Ophthalmology, Bristol Eye Hospital, UK, between January 2008 and December 2017.

Methods

This study included 39,460 eyes operated without a pupil expansion device and 699 eyes operated with the device. Odds ratios for uveitis and PCME when using a pupil expansion device were calculated using univariate and multivariate regression analysis, having age, gender, diabetes, pseudoexfoliation, and pupil expansion device as independent variables. Multivariate Cox regression controlling for age and gender was used to estimate hazard ratios (HR) for Nd : YAG laser capsulotomies.

Results

Postoperative uveitis and PCME were reported in 3.9% and 2.7% of the eyes operated with a pupil expansion device compared to 2.3% and 1.3% operated without the device (p=0.005 and p=0.002, respectively). In univariate regression analysis, eyes with pupil expansion devices showed a higher risk of postoperative uveitis or PMCE after cataract surgery (OR 1.88, 95%CI 1.39-2.55, p<0.001). In multivariate regression analysis, the risk for PMCE was greater among diabetic patients and in eyes with a pupil expansion device than in those without (OR 1.50, 95%CI 1.24-1.83, P<0.001; OR 1.90, 95%CI 1.16-3.11, P=0.01). In Cox regression analysis adjusted for the patient's age and gender, the use of a pupil expansion device was associated with higher Nd : YAG laser capsulotomy rates (HR 1.316, 95%CI 1.011-1.714, P=0.041).

Conclusion

In our large cohort study, the use of pupil expansion devices in cataract surgery was associated with an increased risk of major postoperative complications. Effective anti-inflammatory treatment and follow-up are warranted in eyes operated with a pupil expansion device.

Intermediate Uveitis: A Review

PURPOSE

This review aims to provide an update on the clinical presentation, etiologies, complications, and treatment options in intermediate uveitis (IU).

METHODS

Narrative literature review.

RESULTS

IU affects all age groups with no clear gender predominance and has varied etiologies including systemic illnesses and infectious diseases, or pars planitis. In some instances, IU may be the sole presentation of an underlying associated condition or disease. Management of IU and its complications include administration of corticosteroids, antimetabolites, T-cell inhibitors, and/or biologics, along with surgical interventions, with varying degrees of effectiveness across literature. In particular, increasing evidence of the safety and efficacy of immunomodulatory agents and biologics has seen greater adoption of these therapies in clinical practice.

CONCLUSIONS

IU is an anatomical description of uveitis, involving intraocular inflammation of the vitreous, peripheral retinal vasculature, and pars plana. Various treatment options for intermediate uveitis are currently used in practice.

Long-term Efficacy of TNF-alpha Inhibitors on Persistent Uveitic Macular Edema: A Swiss Multicenter Cohort Study

PURPOSE

To assess the efficacy of tumor necrosis factor-alpha inhibitors (TNFi) on uveitic macular edema (ME) unresponsive to conventional synthetic disease-modifying anti-rheumatic drugs (csDMARDs).

METHODS

This multicenter retrospective study included patients with uveitic ME persisting despite csDMARDs. The effect of an additional TNFi on central retinal thickness (CRT), best corrected visual acuity (BCVA) and corticosteroid need was evaluated.

RESULTS

Thirty-five eyes (26 patients, mean age 42.9 ± 15.2 years) were included. CRT decreased from 425 ± 137 µm to 294 ± 66 µm (p < .001) and 280 ± 48 µm (p < .001) at 1 and 4 years of follow-up, respectively. BCVA improved from 0.28 ± 0.22 to 0.21 ± 0.48 (1 year, p = .013) and 0.08 ± 0.13 logMAR (4 years, p = .002). The proportion of patients requiring systemic corticosteroids decreased from 88.5% to 34.8% (1 year) and 15.4% (4 years).

CONCLUSION

The addition of a TNFi resulted in an improvement of CRT and BCVA for up to 4 years in uveitic ME but rescue treatments were needed for some patients.

Relationship of Epiretinal Membrane Formation and Macular Edema Development in a Large Cohort of Uveitic Eyes

Purpose: To identify the temporal relationship and clinical characteristics of epiretinal membrane (ERM) and macular edema (ME) formation in uveitic eyes.Methods: A total of 269 subjects (444 uveitic eyes) met study inclusion criteria. Comprehensive ophthalmic examination, spectral domain-optical coherence tomography (SD-OCT), and clinical testing were carried out.Results: Of the 444 uveitic eyes, 229 eyes (51.6%) developed an ERM, whereas 87 eyes (19.1%) developed ME. The odds ratios (ORs) of systemic disease causing uveitis and resulting in ERM and ME were significantly higher in posterior uveitis (OR 6.56, 95% CI 2.98-14.46; p < .0001) and panuveitis (OR 10.09, 95% CI 4.05-25.15; p < .0001). Temporal analysis revealed that an ERM was noted concurrently or prior to ME development in 93.8% of eyes.Conclusions: ERM and ME are primarily observed in posterior uveitis and panuveitis associated with systemic diseases. The temporal relationship highlights the importance of characterization of ERM as it relates to the development of uveitic ME.

Outcomes of Pars Plana Vitrectomy for Epiretinal Membrane in Eyes With Coexisting Dry Age-related Macular Degeneration

PURPOSE

There has been limited evidence on the benefits of pars plana vitrectomy with membrane peel (PPV-MP) for epiretinal membrane (ERM) in eyes with dry age-related macular degeneration (AMD). We sought to assess anatomic and functional outcomes of PPV-MP for ERM in this subset of eyes.

DESIGN

A retrospective cohort study.

PARTICIPANTS

Patients with dry AMD who underwent PPV-MP for ERM from January 1, 2010, to December 1, 2016.

METHODS

Visual acuity (VA) and central foveal thickness (CFT) as measured on spectral-domain OCT were recorded and analyzed for the preoperative, 6-month, and final follow-up visits. The presence of cystoid macular edema (CME) and ellipsoid zone (EZ) integrity were recorded and compared with postoperative imaging. Conversion to neovascular AMD in eyes for which at least 2 years of follow-up were available, as confirmed by either OCT and/or fluorescein angiography and documentation of treatment with intravitreal antivascular endothelial growth factor, was recorded and compared between case eyes that underwent PPV-MP versus fellow control eyes.

MAIN OUTCOME MEASURES

Postoperative VA.

RESULTS

A total of 38 eyes from 38 patients met the study criteria. There was a significant improvement in the median (interquartile range, [IQR]) logarithm of the minimum angle of resolution [logMAR] VA from 0.60 (IQR 0.46-1.00) (20/80, Snellen equivalent) at the preoperative visit, to 0.48 (IQR 0.30-0.70) (20/60, Snellen equivalent) at the 6-month follow-up visit (P = 0.04), and to 0.48 (IQR 0.30-0.70) (20/60, Snellen equivalent) at the final visit (P = 0.01). There was a significant median decrease in CFT at the final visit (P < 0.001) compared with the preoperative CFT. Only eyes with either CME or an intact EZ showed significant improvement in median logMAR VA at the final visit compared with the preoperative visit (P = 0.01 and P = 0.004, respectively). In a subgroup analysis of eyes for which a minimum of 2 years of follow-up were available, 4 of 25 (16.0%) vitrectomized eyes and 1 of 25 (4.0%) fellow control eyes progressed to neovascular AMD (P = 0.16).

CONCLUSIONS

PPV-MP appears to confer anatomic and functional improvement in eyes with ERM and coexisting dry AMD. Moreover, greater preoperative CFT, the presence of CME, and an intact EZ were predictors of VA improvement in these eyes.

Intravitreal diclofenac for treatment of refractory uveitis-associated cystoid macular oedema: A before and after clinical study

BACKGROUND

Cystoid macular oedema (CME) is one of the important complications of uveitis leading to irreversible blindness. Currently, there is no gold standard treatment for this condition. The aim of this study was to investigate the effects of single intravitreal diclofenac (IVD) injection on short-term outcome of refractory uveitis-associated CME.

METHODS

This was a prospective clinical study on 16 consecutive patients (16 eyes) with refractory uveitis-associated CME. Intravitreal injection of 500 μg/0.1 ml of diclofenac sodium was given to the patients. The clinical outcomes considered were best-corrected visual acuity (BCVA) change and central macular thickness (CMT) changes in the pre- and postinjection periods. Follow-up examinations were performed at 1 and 4 weeks after the injection.

RESULTS

Age of the patients varied from 18 to 59 years (mean ± SD: 39.5 ± 13.2 years). Ten patients (62.5%) were females. Statistically significant differences were found in the decrease of mean BCVA (logMAR) (p = 0.043) and mean CMT (p = 0.003) during the study period. There was no significant difference in the intraocular pressure (IOP) increase at the end of the study (p = 0.94).

CONCLUSION

Intravitreal diclofenac (IVD) may be a promising treatment for refractory uveitis-associated CME. Further clinical trials with a larger sample size should be conducted to confirm these findings and compare them with other treatments.

The UK Diabetic Retinopathy Electronic Medical Record (UK DR EMR) Users Group, Report 2: real-world data for the impact of cataract surgery on diabetic macular oedema

AIM

To assess the rate of 'treatment-requiring diabetic macular oedema (DMO)' in eyes for the two  years before and after cataract surgery.

METHODS

Multicentre national diabetic retinopathy (DR) database study with anonymised data extraction across 19 centres from an electronic medical record system.

INCLUSION CRITERIA

eyes undergoing cataract surgery in patients with diabetes with no history of DMO prior to study start. The minimum dataset included: age, visual acuity (all time-points), injection episodes, timing of cataract surgery and ETDRS grading of retinopathy and maculopathy.

MAIN OUTCOME MEASURE

rate of developing first episode of treatment-requiring DMO in relation to timing of cataract surgery in the same eye.

RESULTS

4850 eyes met the inclusion criteria. The rate of developing treatment-requiring DMO in this cohort was 2.9% in the year prior to surgery versus 5.3% in the year after surgery (p<0.01). The risk of 'treatment-requiring DMO' increased sharply after surgery, peaking in the 3-6 months' period (annualised rates of 5.2%, 6.8%, 5.6% and 4.0% for the 0-3, 3-6, 6-9 and 9-12 months' post-operative time periods respectively). Risk was associated with pre-operative grade of retinopathy: risk of DMO in the first year post-operatively being 1.0% (no DR pre-operatively), 5.4% (mild non-proliferative diabetic retinopathy; NPDR), 10.0% (moderate NPDR), 13.1% (severe NPDR) and 4.9% (PDR) (p<0.01).

CONCLUSIONS

This large real-world study demonstrates that the rate of developing treatment-requiring DMO increases sharply in the year after cataract surgery for all grades of retinopathy, peaking in the 3-6 months' postoperative period. Patients with moderate and severe NPDR are at particularly high risk.

Characteristics of Macular Edema in Behcet Disease after Intravitreal Bevacizumab Injection

Purpose:

To investigate the effect of intravitreal bevacizumab (IVB) injection on macular edema (ME) secondary to Behcet's disease.

Methods:

This prospective case series included 15 patients with bilateral ME due to Behcet's disease. Intravitreal bevacizumab was injected into the more severely involved eye; the contralateral eye was evaluated as the control. Patients were followed up with comprehensive ocular examination, optical coherence tomography, and fluorescein angiography (FA) for a minimum of 6 months by a single ophthalmologist.

Results:

Patients with a mean age of 30.6 ± 7.4 years received a mean number of 3.3 IVB injections during the 6 months. The mean preinjection vision was 0.6 ± 0.3 and 0.4 ± 0.4 LogMAR in the case and control groups, respectively, with no significant improvement at 6 months. Mean central foveal thickness was 375.3 ± 132.1 and 307.2 ± 84.5 μm in the case and control groups, respectively, and these changed to 401 ± 199.9 (P = 0.65) and 307.7 ± 82.8 μm (P = 0.73) at month 6, respectively. A statistically nonsignificant improvement in ME was observed during the first 3 months in the case group. However, it did not persist up to month 6 on an as-needed basis. IVB injections caused a disproportionate decrease in the thickness of macular subfields. A reduction in disc leakage was observed on FA (P = 0.058). Logistic regression analysis revealed no statistically significant predictive factor for an improvement in visual acuity (VA) and a reduction in foveal thickness.

Conclusion:

During a 6-month period, IVB injections based on an as-needed protocol provided no statistically significant improvement in VA and ME.

Dexamethasone Implant for the Treatment of Type 1 Idiopathic Macular Telangiectasia

PURPOSE

To report our results of 4 patients about the efficacy and safety of intravitreal dexamethasone implant for type 1 idiopathic macular telangiectasia (IMT).

METHODS

Four patients' charts with type 1 IMT treated with intravitreal dexamethasone implant were retrospectively reviewed. All patients underwent full ophthalmic examination including best corrected visual acuity (BCVA), spectral domain optical coherence tomography, and fluorescein angiography. BCVA, central macular thickness (CMT), and macular volume (MV) were evaluated.

RESULTS

The median BCVA was logMAR 0.55 (range 0.2-1.3) at baseline, improved to logMAR 0.45 (range 0.2-1) at 2 months after the first injection, and deteriorated to logMAR 0.7 (range 0.2-1) at final visit. The median CMT was 393 μm (range 283-410 μm) and MV was 2.70 mm(3) (range 1.96-2.87 mm(3)) at baseline. Two months after the first injection median CMT decreased to 327 μm (range 269-356 μm) and MV decreased to 2.45 mm(3) (range 1.93-2.57 mm(3)). At final visit median CMT slightly increased to 342 μm (range 258-444 μm) and MV slightly increased to 2.56 mm(3) (range 1.93-2.89 mm(3)). None of the changes were statistically significant.

CONCLUSION

Considering the effects of dexamethasone on macular edema intravitreal dexamethasone implant can be used in selected cases. Randomized clinical trials with larger sample size are needed for further evaluation.

The effect of topical sodium diclofenac on macular thickness in diabetic eyes after phacoemulsification: a randomized controlled trial

To evaluate the efficacy of prophylactic administration of the topical diclofenac 0.1 % on macular thickness in diabetic patients following phacoemulsification and intraocular lens implantation surgery. In a Randomized double-masked clinical trial, 108 eyes of 108 diabetic patients underwent phacoemulsification and intraocular lens implantation surgery were enrolled. Fifty four eyes received the conventional postoperative care with steroid drop, whereas the other group (54 eyes) was given a preoperative diclofenac drop four times daily in addition to steroid drop and continued 6 weeks after surgery. All patients were evaluated by optical coherence tomography (OCT) preoperatively and days 1, 30, and 90. The outcome measures including best-corrected visual acuity and OCT findings were compared in and between both groups. Mean CMT changed from 239 ± 16 and 235 ± 17 at baseline to 249 ± 15 and 254 ± 28 at 3 months in the case and control groups, respectively(p = 0.003). Mean total volume of macula changed from 7.61 ± 0.22 and 7.56 ± 0.3 at baseline to 7.64 ± 0.22 and 7.65 ± 0.31 at 3 months in the case and control groups, respectively (p = 0.820). In comparison to the quadrants thicknesses and mean of them between groups did not reach the significant level. This study showed that there is a beneficial effect of topical diclofenac for prevention of macular thickness increasing following phacoemulsification in diabetic patients.

Prostaglandin E2 Levels of Aqueous and Vitreous Humor in Ketorolac 0.4% and Nepafenac 0.1% Administered Healthy Rabbits

PURPOSE

To compare the lowering effects of ketorolac 0.4% and nepafenac 0.1% on aqueous and vitreous humor prostaglandin E₂ (PGE₂) levels in rabbits.

METHODS

Ketorolac and nepafenac ophthalmic solutions were administered to the right eyes of 24 healthy rabbits after randomized division into two groups. The left eyes of these rabbits were considered as controls for the two groups. On the 4th day of the experiment, the samples were taken from the aqueous and vitreous humors of the rabbits bilaterally, and PGE₂ levels were measured by an enzyme immune assay kit.

RESULTS

Ketorolac and nepafenac achieved a statistically significant decrease (p<0.001, for each) in PGE₂ levels in the aqueous (11.75 ± 6.15 and 14.75 ± 7.60 pg/mL, respectively) and the vitreous humor (6.58 ± 4.62 and 9.83 ± 4.55 pg/mL, respectively).

CONCLUSIONS

Both ketorolac and nepafenac inhibited PGE₂ levels in both the aqueous and vitreous humors of rabbits. Although PGE₂-lowering effects were similar in the aqueous humor, nepafenac seemed to be more potent than ketorolac in the vitreous humor.

Influence of the vitreomacular interface on the efficacy of intravitreal therapy for uveitis-associated cystoid macular oedema

PURPOSE

To evaluate the effect of the vitreomacular interface (VMI) on treatment efficacy of intravitreal therapy in uveitic cystoid macular oedema (CME).

METHODS

Retrospective analysis of CME resolution, CME recurrence rate and monthly course of central retinal thickness (CRT), retinal volume (RV) and best corrected visual acuity (BCVA) after intravitreal injection with respect to the VMI configuration on spectral-domain OCT using chi-squared test and repeated measures anova adjusted for confounding covariates epiretinal membrane, administered drug and subretinal fluid.

RESULTS

Fifty-nine eyes of 53 patients (mean age: 47.4 ± 16.9 years) were included. VMI status had no effect on complete CME resolution rate (p = 0.16, corrected p-value: 0.32), time until resolution (p = 0.09, corrected p-value: 0.27) or CME relapse rate (p = 0.29, corrected p-value: 0.29). Change over time did not differ among the VMI configuration groups for BVCA (p = 0.82) and RV (p = 0.18), but CRT decrease was greater and faster in the posterior vitreous detachment (PVD) group compared to the posterior vitreous attachment (PVA) and vitreous macular adhesion (VMA) groups (p = 0.04). Also, the percentage of patients experiencing a ≥ 20% CRT thickness decrease after intravitreal injection was greater in the PVD group (83%) compared to the VMA (64%) and the PVA (16%) group (p = 0.027), however, not after correction for multiple testing (corrected p-value: 0.11).

CONCLUSION

The VMI configuration seems to be a factor contributing to treatment efficacy in uveitic CME in terms of CRT decrease, although BCVA outcome did not differ according to VMI status.

Retinal Thickening and Photoreceptor Loss in HIV Eyes without Retinitis

Purpose

To determine the presence of structural changes in HIV retinae (i.e., photoreceptor density and retinal thickness in the macula) compared with age-matched HIV-negative controls.

Methods

Cohort of patients with known HIV under CART (combination Antiretroviral Therapy) treatment were examined with a flood-illuminated retinal AO camera to assess the cone photoreceptor mosaic and spectral-domain optical coherence tomography (SD-OCT) to assess retinal layers and retinal thickness.

Results

Twenty-four eyes of 12 patients (n = 6 HIV-positive and 6 HIV-negative) were imaged with the adaptive optics camera. In each of the regions of interest studied (nasal, temporal, superior, inferior), the HIV group had significantly less mean cone photoreceptor density compared with age-matched controls (difference range, 4,308–6,872 cones/mm²). A different subset of forty eyes of 20 patients (n = 10 HIV-positive and 10 HIV-negative) was included in the retinal thickness measurements and retinal layer segmentation with the SD-OCT. We observed significant thickening in HIV positive eyes in the total retinal thickness at the foveal center, and in each of the three horizontal B-scans (through the macular center, superior, and inferior to the fovea). We also noted that the inner retina (combined thickness from ILM through RNFL to GCL layer) was also significantly thickened in all the different locations scanned compared with HIV-negative controls.

Conclusion

Our present study shows that the cone photoreceptor density is significantly reduced in HIV retinae compared with age-matched controls. HIV retinae also have increased macular retinal thickness that may be caused by inner retinal edema secondary to retinovascular disease in HIV. The interaction of photoreceptors with the aging RPE, as well as possible low-grade ocular inflammation causing diffuse inner retinal edema, may be the key to the progressive vision changes in HIV-positive patients without overt retinitis.

Efficacy and vitreous levels of topical NSAIDs

INTRODUCTION

Nonsteroidal anti-inflammatory drugs (NSAIDs) are one of the most commonly prescribed medications and are routinely used for their analgesic, antipyretic, and anti-inflammatory properties. Because of their potent cyclooxygenase-inhibitory activity, they can inhibit pro-inflammatory prostaglandin synthesis, leading to complex inflammatory cascades. NSAIDs have been broadly used systemically for many decades and have recently become commercially available in the form of topical ophthalmic formulations. NSAIDs are weak acids with pKa values mostly between 3.5 and 4.5 and are poorly water-soluble. New, aqueous ophthalmic solutions of NSAIDs that afford better tissue penetration have recently been developed. In ophthalmological practice, topical NSAIDs are mostly used to stabilize pupillary dilation during intraocular surgery, manage postoperative pain and inflammation, and treat pseudophakic cystoid macular edema.

AREAS COVERED

This review focuses on the vitreous penetration of topical NSAIDs and their potential clinical applications in the treatment of retinal diseases.

EXPERT OPINION

A growing body of evidence suggests that NSAIDs may be beneficial in the treatment of age-related macular degeneration, diabetic retinopathy, and ocular tumors. Recent studies from our group and other authors have shown that the vitreous levels of NSAID exceed the median inhibitory concentration, which can significantly decrease vitreous PGE2 levels.

Optical coherence tomography-guided ranibizumab injection for cystoid macular edema in well-controlled uveitis: twelve-month outcomes

PURPOSE

To determine whether serial ranibizumab injections are effective in the treatment of cystoid macular edema in patients with chronic controlled noninfectious uveitis.

METHODS

Five eyes of 5 patients were included in a prospective noncomparative therapeutic trial. They received intravitreal injections of ranibizumab at Day 0 and were followed monthly for 1 year. Injections were repeated monthly if persistent or new cystic edema manifested on optical coherence tomography. The primary outcome measure was the mean change in best-corrected visual acuity from baseline at 12 months. Secondary outcome measures included mean percentage change in central subfield retinal thickness (CST) and incidence of adverse events through Month 24.

RESULTS

Thirty-two injections were performed over the study period. At 1 year, the mean increase in acuity was 12.2 Early Treatment for Diabetic Retinopathy Study letters (P = 0.015). There was a statistically significant increase in visual acuity over time (P = 0.002). The CST decreased by 31.4%, 46.0%, 37.6%, and 45.4% relative to baseline at 3, 6, 9, and 12 months, respectively (P = 0.003). One patient experienced recurrence of uveitis with subsequent cataract and glaucoma progression.

CONCLUSION

Optical coherence tomography-guided monthly intravitreal ranibizumab injections delivered over the course of 1 year resulted in improved vision and reduced central retinal thickness.

The effects of intravitreal bevacizumab in infectious and noninfectious uveitic macular edema

Background/Aims. To assess the effect of intravitreal bevacizumab injection (IVBI) for the treatment of macular edema due to infectious and noninfectious uveitides. Design. Retrospective interventional case series. Methods. A chart review was performed on all the patients who were diagnosed with uveitic macular edema (UME) and received 1.25 mg of IVBI at two referral centers in Riyadh, Saudi Arabia. All included patients had their visual acuity and macular thickness analyzed at baseline and at 1 and 3 months following IVBI and any sign of reactivation was noted. Results. The mean age of patients was 41 ± 16 years with a mean followup of 4 ± 1 months. Ten patients had idiopathic intermediate uveitis, 9 patients had Behcet's disease, 10 had idiopathic panuveitis, and twelve patients had presumed ocular tuberculosis uveitis. Following IVBI, the mean LogMAR visual acuity improved from 0.8 ± 0.8 at baseline to 0.4 ± 0.5 at 1 month and 0.3 ± 0.5 at 3 months (P < 0.002, at 3 months). The mean macular thickness was 430 ± 132 μm at baseline. Following IVBI macular thickness improved to 286 ± 93 μm at 1 month and to 265 ± 88 μm at 3 months of followup (P < 0.001, at 3 months). Conclusion. Bevacizumab was effective in the management of UME associated with both infectious and noninfectious uveitides. Intravitreal bevacizumab induced remission of UME with infectious uveitis and had no immunosuppressive effect against infectious agents.

Visual acuity and microperimetric mapping of lesion area in eyes with inflammatory cystoid macular oedema

PURPOSE

  To evaluate the effect of fluid accumulation on local visual function in inflammatory cystoid-macular-edema (ICME).

METHODS

  This cross-sectional study applied optical-coherence-tomography over a 12×12 fovea-centered field in 50 patients with ICME and mapped the extent of fluid-filled spaces in various retinal layers, of subretinal-fluid and of diffuse-edema. Regression analysis examined effect of planimetric fluid-distribution on best-corrected-visual-acuity (BCVA) and mean microperimetric-sensitivity.

RESULTS

  BCVA decreased with increasing central-neuroretinal-thickness (r= 0.52, p= 0.001), total central-retinal-thickness, including subneuroretinal-fluid (r= 0.41, p= 0.006), total cystoid-and-diffuse edema-area (r= 0.35, p= 0.036) and cystoid inner-nuclear-layer area (r= 0.39, p= 0.02). Mean retinal-sensitivity decreased with increasing diffuse edema-area (r= -0.86, p<0.0001), total cystoid-and-diffuse edema-area (r= -0.54, p= 0.001), cystoid inner-nuclear-layer area (r= -0.46, p= 0.008) and cystoid ganglion-cell-layer area (r= -0.6, p=0.049), central-neuroretinal-thickness (r= -0.42, p= 0.028) and total central-retinal-thickness (r= -0.34, p= 0.039). In multivariate-analyses BCVA was best described by central-neuroretinal-thickness, duration of edema, total cystoid-and-diffuse edema-area and cystoid inner-nuclear-layer area (R(2) = 0.5, p= 0.002). Mean retinal-sensitivity was best described by diffuse edema-area, total cystoid-and-diffuse edema-area and central-neuroretinal-thickness (R(2) = 0.75, p< 0.0001). Subretinal-fluid area and cystoid outer-nuclear/Henle's layer area had no effect on either BCVA or microperimetry.

CONCLUSIONS

  Thickening of the neurosensory-fovea, not subfoveal-fluid, had major impact on both BCVA and retinal-sensitivity. The extent of edema in inner retinal layers also had major impact on both of these two functional parameters. Visual-impairment seems to differ depending on the layers involved, thus different types of fluid accumulation may potentially be given varying treatment priorities.

Anti-vascular endothelial growth factor for macular oedema secondary to central retinal vein occlusion

BACKGROUND

Central retinal vein occlusion (CRVO) is a relatively common retinal vascular disorder in which macular oedema may develop, with a consequent reduction in visual acuity. Until recently there has been no treatment of proven benefit, but growing evidence supports the use of anti-vascular endothelial growth factor (anti-VEGF) agents.

OBJECTIVES

To investigate the effectiveness and safety of anti-VEGF therapies for the treatment of macular oedema secondary to CRVO.

SEARCH METHODS

We searched CENTRAL (which contains the Cochrane Central Register of Controlled Trials (CENTRAL) and the Cochrane Eyes and Vision Group Trials Register) (The Cochrane Library 2013, Issue 10), Ovid MEDLINE (January 1950 to October 2013), EMBASE (January 1980 to October 2013), Latin American and Caribbean Health Sciences Literature Database (LILACS) (January 1982 to October 2013), Cumulative Index to Nursing and Allied Health Literature (CINAHL) (January 1937 to October 2013), OpenGrey, OpenSIGLE (January 1950 to October 2013), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com), ClinicalTrials.gov (www.clinicaltrials.gov), the WHO International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en) and Web of Science Conference Proceedings Citation Index-Science (CPCI-S). There were no language or date restrictions in the electronic search for trials. The electronic databases and clinical trials registers were last searched on 29th October 2013.

SELECTION CRITERIA

We considered randomised controlled trials (RCTs) that compared intravitreal anti-VEGF agents of any dose or duration to sham injection or no treatment. We focused on studies that included individuals of any age or gender and a minimum of six months follow-up.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and extracted data. The primary outcome was the proportion of participants with a gain in best-corrected visual acuity (BCVA) from baseline of greater than or equal to 15 letters (3 lines) on the Early Treatment of Diabetic Retinopathy Study (ETDRS) chart. Secondary outcomes included the proportion of participants with a loss of 15 letters or more of BCVA, the mean change from baseline BCVA, the mean change in central retinal thickness (CRT), the number and type of complications or adverse outcomes, and the number of additional interventions administered. Where available, we also presented quality of life and economic data.

MAIN RESULTS

We found six RCTs that met the inclusion criteria after independent and duplicate review of the search results. These RCTs included 937 participants and compared outcomes at six months to sham injection for four anti-VEGF agents: aflibercept (VEGF Trap-Eye, Eylea), bevacizumab (Avastin), pegaptanib sodium (Macugen) and ranibizumab (Lucentis). Three trials were conducted in Norway, Sweden and the USA, and three trials were multicentre, one including centres in the USA, Canada, India, Israel, Argentina and Columbia, a second including centres in the USA, Australia, France, Germany, Israel, and Spain, and a third including centres in Austria, France, Germany, Hungary, Italy, Latvia, Australia, Japan, Singapore and South Korea. We performed meta-analysis on three key visual outcomes, using data from up to six trials. High-quality evidence from six trials revealed that participants receiving intravitreal anti-VEGF treatment were 2.71 times more likely to gain at least 15 letters of visual acuity at six months compared to participants treated with sham injections (risk ratio (RR) 2.71; 95% confidence intervals (CI) 2.10 to 3.49). High-quality evidence from five trials suggested anti-VEGF treatment was associated with an 80% lower risk of losing at least 15 letters of visual acuity at six months compared to sham injection (RR 0.20; 95% CI 0.12 to 0.34). Moderate-quality evidence from three trials (481 participants) revealed that the mean reduction from baseline to six months in central retinal thickness was 267.4 µm (95% CI 211.4 µm to 323.4 µm) greater in participants treated with anti-VEGF than in participants treated with sham. The meta-analyses demonstrate that treatment with anti-VEGF is associated with a clinically meaningful gain in vision at six months. One trial demonstrated sustained benefit at 12 months compared to sham. No significant ocular or systemic safety concerns were identified in this time period.

AUTHORS' CONCLUSIONS

Compared to no treatment, repeated intravitreal injection of anti-VEGF agents in eyes with CRVO macular oedema improved visual outcomes at six months. All agents were relatively well tolerated with a low incidence of adverse effects in the short term. Future trials should address the relative efficacy and safety of the anti-VEGF agents and other treatments, including intravitreal corticosteroids, for longer-term outcomes.

Prophylactic postoperative ketorolac improves outcomes in diabetic patients assigned for cataract surgery

Objective

To evaluate the prophylactic role of topical non-steroidal anti-inflammatory drugs in reducing the incidence of central macular edema (CME) in diabetic eyes post-cataract surgery.

Patients and methods

This study included 86 eyes (70 patients) with high risk characteristics for the development of CME after cataract surgery. All patients underwent phacoemulsification and intraocular lens implantation. Patients were divided into two equal groups (n = 43 [eyes]): a control group given topical dexamethasone 0.1%, four times/day for 12 weeks postoperatively and a study group given topical ketorolac tromethamine 0.4% twice daily in addition to topical dexamethasone 0.1% four times daily for 12 weeks. Patients were examined at 3, 6, and 12 weeks postoperatively for evaluation of CME development. The main study outcome was the change in the retinal fovea thickness measured with ocular coherence topography.

Results

Ten eyes developed CME (11.6%); eight eyes in the control group and only two eyes in the study group. Mean retinal fovea thickness was significantly higher in the control group compared to the study group. Moreover, eyes of the control group developed CME significantly earlier than those of the study group.

Conclusion

Prophylactic postoperative ketorolac 0.4% may have a role in reducing the frequency and severity of CME in diabetic eyes post-cataract surgery.

Experimental uveitis can be maintained in rabbits for a period of six weeks after a safe sensitization method

PURPOSE

New treatments against long-lasting uveitis need to be tested. Our aim was to develop a six-week model of uveitis in rabbits.

METHODS

Rabbits were presensitized with an s.c. injection of Mycobacterium tuberculosis H37RA emulsified with TiterMax Gold adjuvant. Uveitis was induced at day 28 and 50, by intravitreal challenges of antigen suspension. Ocular inflammation was assessed till euthanasia at day 71 after s.c. injection of M. tuberculosis H37RA by: (a) the number of inflammatory cells in aqueous humor (AH); (b) the protein concentration in AH; (c) the clinical score (mean of conjunctival hyperaemia, conjunctival chemosis, oedema and secretion); (d) the microscopical score (mean presence of fibrin and synechiae, aqueous cell density and aqueous flare grade, as scored by slit lamp).

RESULTS

At the sites of presensitization injection, rabbits presented flat nodules which progressively vanished. The first challenge induced a significant increase in the four parameters (p < 0.05 the Wilcoxon/Kruskal-Wallis test). The AH contained 764 ± 82 cells/µl and 32 ± 0.77 mg protein/ml. During the following days, inflammatory parameters decreased slightly. The second intravitreal challenge increased inflammation (3564 ± 228 cells/µl AH and 31 ± 1 mg protein/ml), which remained at a high level for a longer period of time.

CONCLUSION

We developed a model of long-term uveitis, which could be maintained in rabbits for at least six weeks. Such a model could be used to test the efficacy of either new drugs or various drug delivery systems intended to deliver active agents during a few months.

Loteprednol etabonate ophthalmic suspension 0.5 %: efficacy and safety for postoperative anti-inflammatory use

Topical corticosteroids are routinely used as postoperative ocular anti-inflammatory drugs; however, adverse effects such as increased intraocular pressure (IOP) are observed with their use. While older corticosteroids such as dexamethasone and prednisolone acetate offer good anti-inflammatory efficacy, clinically significant increases in IOP (≥10 mmHg) are often associated with their use. Loteprednol etabonate, a novel C-20 ester-based corticosteroid, was retrometabolically designed to offer potent anti-inflammatory efficacy but with decreased impact on IOP. After exerting its therapeutic effects on the site of action, loteprednol etabonate is rapidly converted to inactive metabolites, resulting in fewer adverse effects. Randomized controlled studies have demonstrated the clinical efficacy and safety of loteprednol etabonate ophthalmic suspension 0.5 % for the treatment of postoperative inflammation in post-cataract patients with few patients, if any, exhibiting clinically significant increases (≥10 mmHg) in IOP. Furthermore, safety studies demonstrated a minimal effect of loteprednol etabonate on IOP with long-term use or in steroid responders with a much lower propensity to increase IOP relative to prednisolone acetate or dexamethasone. The anti-inflammatory treatment effect of loteprednol etabonate appears to be similar to that of rimexolone and difluprednate with less impact on IOP compared to difluprednate, although confirmatory comparative studies are needed. The available clinical data suggest that loteprednol etabonate is an efficacious and safe corticosteroid for the treatment of postoperative inflammation.

Transcriptional regulation of aquaporin-3 in human retinal pigment epithelial cells

The expression of aquaporin (AQP) water channels may influence the development of retinal edema. We investigated the transcriptional regulation of AQP3 in cultured human retinal pigment epithelial (RPE) cells. As shown by RT-PCR and immunocytochemistry, cultured RPE cells express AQP3 mRNA and protein. The AQP3 mRNA level in RPE cells was elevated under the following conditions: chemical hypoxia induced by CoCl(2), hyperosmolarity induced by 100 mM NaCl, and upon stimulation of the cultures with PDGF, arachidonic acid, prostaglandin E(2), and blood serum, respectively. Chemical hypoxia increased AQP3 gene expression through MEK/ERK and JNK activation. The hyperosmolarity-, PDGF-, and serum-induced upregulation of AQP3 was prevented by inhibition of the phospholipase A(2), but not by inhibition of the cyclooxygenase. Triamcinolone acetonide prevented the upregulation of AQP3 induced by arachidonic acid and prostaglandin E(2), but not by the other factors tested. It is concluded that AQP3 is transcriptionally activated in RPE cells by various pathogenic factors involved in the development of retinal edema in situ. Activation of phospholipase A(2) is a critical factor which induces AQP3 in RPE cells.

Postcataract surgical inflammation

PURPOSE OF REVIEW

To describe the epidemiology, pathogenesis, and recent developments in the diagnosis and management of postcataract surgery inflammation.

RECENT FINDINGS

In patients with pre-existing uveitis, control of inflammation with topical and/or systemic therapy for 3 months preoperatively continues to be important in lessening the risk of postoperative inflammation and complications. During cataract surgery, intraocular lens selection in these patients is important. Recent literature suggests that modern intraocular lenses (IOLs), particularly hydrophilic or hydrophobic acrylic lenses, generally have good uveal biocompatibility in uveitic patients. The postoperative course can be complicated by inflammation and cystoid macular edema (CME), and in uveitic patients, intensive perioperative steroid treatment can lessen these complications. Recent studies show that in uveitic patients, the improvement in CME and inflammation after intravitreal triamcinolone is better than after orbital floor triamcinolone injection, but that a single intraoperative orbital floor injection of triamcinolone is as effective as a 4-week course of postoperative oral prednisolone. Although postoperative inflammation in uveitic patients may be due to recurrence of uveitis, one must recognize other important potential causes of postoperative inflammation and treat accordingly.

SUMMARY

Most patients with postcataract inflammation have good visual outcomes provided that the cause is recognized and that there is adequate perioperative planning in patients predisposed to inflammation.

Ketorolac therapy for the prevention of acute pseudophakic cystoid macular edema: a systematic review

To assess the effectiveness of ketorolac vs control for prevention of acute pseudophakic cystoid macular edema (CME). The following databases were searched: Medline (1950-June 11, 2011), The Cochrane Library (Issue 2, 2011), and the TRIP Database (up to 11 June 2011), using no language or other limits. Randomized controlled clinical trials (RCTs) were included that consisted of patients with acute pseudophakic cystoid macular edema, those comparing ketorolac with control, and those having at least a minimum follow-up of 28 days. In the four RCTs evaluating ketorolac vs control, treatment with ketorolac significantly reduced the risk of CME development at the end of treatment (≈ 4 weeks) compared to control (P=0.008; 95% confidence interval (0.03-0.58)). When analyzed individually, each individual study was statistically nonsignificant in its findings with the exception of one study. When the pooled relative risk was calculated, the large sample size of this systematic review led to overall statistical significance, which is attributable to the review's large sample size and not to the individual studies themselves. In this systematic review of four RCTs, two of which compared ketorolac with no treatment and two of which evaluated ketorolac vs placebo drops, treatment with ketorolac significantly reduced the risk of developing CME at the end of ≈ 4 weeks of treatment compared with controls. These results, however, should be interpreted with caution considering the paucity of large randomized clinical trials in the literature.

Hypoxia-ischemia and retinal ganglion cell damage

Retinal hypoxia is the potentially blinding mechanism underlying a number of sight-threatening disorders including central retinal artery occlusion, ischemic central retinal vein thrombosis, complications of diabetic eye disease and some types of glaucoma. Hypoxia is implicated in loss of retinal ganglion cells (RGCs) occurring in such conditions. RGC death occurs by apoptosis or necrosis. Hypoxia-ischemia induces the expression of hypoxia inducible factor-1α and its target genes such as vascular endothelial growth factor (VEGF) and nitric oxide synthase (NOS). Increased production of VEGF results in disruption of the blood retinal barrier leading to retinal edema. Enhanced expression of NOS results in increased production of nitric oxide which may be toxic to the cells resulting in their death. Excess glutamate release in hypoxic-ischemic conditions causes excitotoxic damage to the RGCs through activation of ionotropic and metabotropic glutamate receptors. Activation of glutamate receptors is thought to initiate damage in the retina by a cascade of biochemical effects such as neuronal NOS activation and increase in intracellular Ca²⁺ which has been described as a major contributing factor to RGC loss. Excess production of proinflammatory cytokines also mediates cell damage. Besides the above, free-radicals generated in hypoxic-ischemic conditions result in RGC loss because of an imbalance between antioxidant- and oxidant-generating systems. Although many advances have been made in understanding the mediators and mechanisms of injury, strategies to improve the damage are lacking. Measures to prevent neuronal injury have to be developed.

Anti-vascular endothelial growth factor for macular edema secondary to central retinal vein occlusion

BACKGROUND

Central retinal vein occlusion (CRVO) is a common retinal vascular disorder in which macular edema (ME) may develop, with a consequent reduction in visual acuity. The visual prognosis in CRVO-ME is poor in a substantial proportion of patients, especially those with the ischemic subtype, and until recently there has been no treatment of proven benefit. Macular grid laser treatment is ineffective, and whilst a few recent randomized controlled trials (RCTs) suggest short-term gains in visual acuity with intravitreal steroids for patients with non-ischemic CRVO-ME, there is no established treatment for ischemic CRVO-ME. Anti-vascular endothelial growth factor (anti-VEGF) agents have been used to treat ME resulting from a variety of causes and may represent a treatment option for CRVO-ME.

OBJECTIVES

To investigate the effectiveness and safety of intravitreal anti-VEGF agents in the treatment of CRVO-ME.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (which contains the Cochrane Eyes and Vision Group Trials Register) (The Cochrane Library 2010, Issue 8), MEDLINE (January 1950 to August 2010), EMBASE (January 1980 to August 2010), Latin American and Caribbean Health Sciences Literature Database (LILACS) (January 1982 to August 2010), Cumulative Index to Nursing and Allied Health Literature (CINAHL) (January 1937 to August 2010), OpenSIGLE (January 1950 to August 2010), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com) and ClinicalTrials.gov (www.clinicaltrials.gov). There were no language or date restrictions in the search for trials. The electronic databases were last searched on 10 August 2010.

SELECTION CRITERIA

We considered RCTs that compared intravitreal anti-VEGF agents of any dose or duration to sham injection or no treatment. We focused on studies that included individuals of any age or gender with unilateral or bilateral disease and a minimum of six months follow up. Secondarily, we considered non-randomized studies with the same criteria, but did not conduct a separate electronic search for these.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and extracted data.

MAIN RESULTS

We found two RCTs that met the inclusion criteria after independent and duplicate review of the search results. These RCTs utilized different anti-VEGF agents which cannot be assumed to be directly comparable. We, therefore, performed no meta-analysis. Evidence from these trials and from other non-randomized case series is summarized in this review.

AUTHORS' CONCLUSIONS

Ranibizumab and pegaptanib sodium have shown promise in the short-term treatment of non-ischemic CRVO-ME. However, effectiveness and safety data from larger RCTs with follow up beyond six months are not yet available. There are no RCT data on anti-VEGF agents in ischemic CRVO-ME. The use of anti-VEGF agents to treat this condition therefore remains experimental.

Short-term results of a single intravitreal bevacizumab (avastin) injection versus a single intravitreal triamcinolone acetonide (kenacort) injection for the management of refractory noninfectious uveitic cystoid macular edema

PURPOSE

To report the short-term results of a single intravitreal injection of bevacizumab (IVB) versus a single intravitreal injection of triamcinolone acetonide (IVT) to treat refractory noninfectious uveitic cystoid macular edema (CME).

METHODS

Twenty-eight consecutive patients (36 eyes) were retrospectively included. Patients received either 2.5 mg of IVB (16 eyes) or 4 mg of IVT (20 eyes).

RESULTS

In the IVT group, baseline best-corrected visual acuity (BCVA) was logMAR 1.1 +/- 0.2, and improved to 0.7 +/- 0.3 (p < .001) at 6 months. In the IVB group, baseline BCVA was logMAR of 1.2 +/- 0.4 and improved to 0.8 +/- 0.4 at 6 months (p = .031). At 6 months, central macular thickness (CMT) in the IVT group improved from 454.8 +/- 238.9 microm to 296 +/- 134.4 microm (p < .0001).

CONCLUSION

A single IVT injection improves BCVA and reduces CMT more effectively than IVB in refractory noninfectious uveitic CME at 6 months.

Etiology and treatment of the inflammatory causes of cystoid macular edema

Cystoid macular edema in its various forms can be considered one of the leading causes of central vision loss in the developed world. It occurs in a wide variety of pathologic conditions and represents the final common pathway of several basic processes. Therapeutic approaches to cystoid macular edema depend on a clear understanding of its contributing pathophysiologic mechanisms. This review will discuss the mechanism of ocular inflammation in cystoid macular edema with a particular focus on the inflammatory causes: post-operative, uveitic, and after laser procedures. A variety of pharmacologic agents targeting inflammatory molecules have been shown to reduce macular edema and improve visual function. However, the long-term efficacy and safety of most new therapies have yet to be established in controlled clinical trials.

Retinal thickening in iridocyclitis

PURPOSE

To determine the frequency of retinal thickening (RT) in eyes with iridocyclitis and to examine the correlations among anterior chamber (AC) inflammation, RT, and visual acuity.

DESIGN

Retrospective, observational case series.

METHODS

Records were reviewed of patients seen at the Duke University Eye Center Uveitis Clinic from January 2002 through March 2008. Patients with unilateral iridocyclitis without panuveitis, vitreitis, pars planitis, posterior uveitis, or a combination thereof who had undergone optical coherence tomography (OCT) of both eyes were included. The AC cell grade and OCT-RT measurements were recorded. Subretinal fluid and intraretinal cysts were determined from OCT scans according to Duke Reading Center guidelines.

RESULTS

Forty-three patients were studied. RT typically was present in a ring-like distribution around the fovea. The median difference between the study eye and fellow eye in RT was statistically significant for total macular volume (TMV) and for all OCT subfields (P < .001). In the study eye, there was a modest correlation between the RT and AC cell grade for the OCT-TMV (P = .039; r(2) = 0.1) and the subfield comprised of the quadrants in the outer ring on OCT (P = .027; r(2) = 0.12), and between RT and visual acuity for OCT-TMV and all but the central subfields (P = .003 to .007; r(2) = 0.261 to 0.227). RT decreased after anti-inflammatory therapy.

CONCLUSIONS

RT is strongly associated with iridocyclitis and decreases after treatment. RT, as determined by OCT, is a useful clinical parameter to evaluate patients with iridocyclitis and to monitor response to treatment.

Etiology and treatment of macular edema

PURPOSE

To summarize current concepts and recent literature regarding the pathogenesis, clinical substrates, and treatment of macular edema, in light of evolving pharmacologic and surgical approaches to this prevalent cause of vision loss.

DESIGN

Interpretive essay.

METHODS

Review and synthesis of selected recent literature, with interpretation and perspective.

RESULTS

Macular edema occurs in a wide variety of pathologic conditions and represents the final common phenotype of several basic pathophysiologic processes. A variety of pharmacologic agents targeting inflammatory and vasopermeability molecules have been shown to reduce macular edema and improve visual function over the short-term. Vitreous surgery effectively addresses the tractional components of macular edema, where present. Despite recent advances, laser photocoagulation remains the treatment of choice for macular edema associated with nondiffuse patterns of vascular leakage.

CONCLUSIONS

Effective management of macular edema is based on recognizing and addressing the pathogenic factors that are operative in a given disease setting. Although treatment options are expanding with the development of new drugs and surgical procedures, the long-term efficacy and safety of most new approaches have yet to be established in controlled clinical trials.

Intravitreal triamcinolone for intraocular inflammation and associated macular edema

Triamcinolone acetonide (TA) is a corticosteroid that has many uses in the treatment of ocular diseases because of its potent anti-inflammatory and anti-permeability actions. Intraocular inflammation broadly referred to as uveitis can result from several causes, including the immune system and after ophthalmic surgery. One of the most common reasons for vision loss with uveitis is macular edema. TA has been used for many years as an intravitreal injection for the treatment of ocular diseases. Several case control studies have been reported showing the efficacy of TA in the treatment of intraocular inflammation and associated macular edema caused by Behcet's disease, Vogt-Koyanagi-Harada syndrome, sympathetic ophthalmia and white dot syndromes. It has also been shown efficacious in cases of pars planitis and idiopathic posterior uveitis. Some authors have reported its use in postoperative cystoid macular edema. Many of the studies on the use of TA in controlling intraocular inflammation and concomitant macular edema showed its effect to be transient in many patients requiring reinjection. Complications can arise from intravitreal injection of TA including elevated intraocular pressure and cataract. Rarely, it can be associated with infectious and non-infectious endophthalmitis. TA may be useful as an adjuvant in the treatment of uveitis and its associated macular edema, especially in patients resistant or intolerant to standard treatment.

Cystoid macular edema

We review the epidemiology, pathophysiology, and etiology of cystoid macular edema (CME). Inflammatory, diabetic, post-cataract, and macular edema due to age-related macular degeneration is described. The role of chronic inflammation and hypoxia and direct macular traction is evaluated in each case according to different views from the literature. The different diagnostic methods for evaluating the edema are described. Special attention is given to fluoroangiography and the most modern methods of macula examination, such as ocular coherence tomography and multifocal electroretinography. Finally, we discuss the treatment of cystoid macular edema in relation to its etiology. In this chapter we briefly refer to the therapeutic value of laser treatment especially in diabetic maculopathy or vitrectomy in some selected cases. Our paper is focused mainly on recent therapeutic treatment with intravitreal injection of triamcinolone acetonide and anti-VEGF factors like bevacizumab (Avastin), ranibizumab (Lucentis), pegaptamid (Macugen), and others. The goal of this paper is to review the current status of this treatment for macular edema due to diabetic maculopathy, central retinal vein occlusion and post-cataract surgery. For this reason the results of recent multicenter clinical trials are quoted, as also our experience on the use of intravitreal injections of anti-VEGF factors and we discuss its value in clinical practice.

Dexamethasone inhibits leukocyte accumulation and vascular permeability in retina of streptozotocin-induced diabetic rats via reducing vascular endothelial growth factor and intercellular adhesion molecule-1 expression

Intravitreal injection of corticosteroid has been used to treat diabetic macular edema, however, the exact mechanism remains unknown. In the present experiment, four weeks after streptozotocin administration, intravitreal injection of dexamethasone (50 microg/10 microl) was performed. After 2 d injection, we investigated the effect of dexamethasone on leukocyte accumulation, vascular permeability and the expression of vascular endothelial growth factor (VEGF) and intercellular adhesion molecule-1 (ICAM-1) in streptozotocin-diabetic rats. Accumulated leukocytes were counted in vivo by acridine orange leukocyte fluorography, the retinal vascular permeability was measured by the Evans blue assay. The mRNA and protein level of VEGF and ICAM-1 were analyzed with real-time quantitative polymerase chain reaction (PCR) and enzyme-linked immunosorbent assay (ELISA) respectively. Dexamethasone downregulated VEGF and ICAM-1 expression in diabetic rats which correlated with its effect on leukocytes accumulation and retinal vascular permeability. The present data revealed that dexamethasone may inhibit retinal accumulation and leukostasis accumulation and vascular permeability through its blockage on VEGF and ICAM-1 expression.

Rat model for anterior segment intraocular surgery induced blood-retinal barrier breakdown

PURPOSE

To develop a practical rat model of blood-retinal barrier (BRB) breakdown induced by anterior segment intraocular surgery.

METHODS

A 27-gauge needle attached to infusion tubing running to a bottle of balanced salt solution was inserted through the limbus into the rat anterior chamber. The pressure of the balanced salt solution was oscillated from 0 to 12 mm Hg above the atmospheric pressure for 30 times. The needle was removed and the anterior chamber was formed. Then the eye was exposed vertically to the light of the operating microscope. The contralateral eye was left untreated. The eyes were applied with ofloxacin ophthalmic solution after surgery. At several time points after surgery, the integrity of the BRB was assessed by fluorescence fundus angiography, optical coherence tomography, immunohistochemical staining for serum albumin and quantitative measurement using Evans blue as a tracer.

RESULTS

The extravasation of fluorescein, the increased central retinal thickness, strong staining for albumin in the retina and substantially elevated retinal Evans blue leakage demonstrated BRB breakdown after anterior segment intraocular surgery. On the 1st day after surgery, the model group showed a statistically significant elevation in the retinal Evans blue leakage as compared to the contralateral control group and the normal control group. These increased and reached the peak on the 2nd day after surgery and decreased to the point that there was no significant difference as compared to the contralateral control group and the normal control group on the 7th day after surgery.

CONCLUSIONS

This study establishes a practical rat model of BRB breakdown induced by anterior segment intraocular surgery.

Intravitreal bevacizumab for treatment of uveitic macular edema

PURPOSE

To evaluate the short-term safety and efficacy of intravitreal bevacizumab for the treatment of cystoid macular edema (CME) secondary to uveitis.

DESIGN

Retrospective, noncomparative, interventional case series.

PARTICIPANTS

Thirteen patients undergoing treatment for recalcitrant uveitic macular edema at one referral center.

METHODS

Charts of patients who received one 2.5-mg intravitreal injection of bevacizumab in one eye were reviewed for clinical information including best-corrected Snellen visual acuity (VA), examination findings, optical coherence tomography (OCT) results, and fluorescein angiography results. Kaplan-Meier survival analysis was used to calculate probability success rates. The statistical significance of change in mean retinal thickness and VA was assessed using repeated-measures analysis of variance.

MAIN OUTCOME MEASURES

Assessments of changes in best-corrected Snellen VA and OCT retinal thickness were made.

RESULTS

Six (46.15%) patients had a decrease in foveal thickness at the end of the follow-up, whereas 5 (38.4%) patients had an improvement of VA by > or =2 lines 84 days or more after the injection. Mean retinal thickness showed a significant decrease over the follow-up (P<0.02). The change in mean logarithm of the minimum angle of resolution VA over the follow-up was not significant (P>0.05). Survival analysis showed that the probability of any improvement in VA increased progressively starting at 6 weeks and reached 81% at 14 weeks. No significant ocular or systemic adverse effects were observed.

CONCLUSIONS

These results suggest that a single intravitreal injection of bevacizumab is well tolerated and is associated with short-term improvement in VA and decreased OCT retinal thickness in a considerable proportion of patients with uveitic CME resistant to conventional therapy. Further evaluation of intravitreal bevacizumab for uveitic CME in controlled randomized studies is warranted.

Changes in membrane conductance play a pathogenic role in osmotic glial cell swelling in detached retinas

Detachment of the neural retina from the pigment epithelium may be associated with tissue edema; however, the mechanisms of fluid accumulation are not understood. Because retinal detachment is usually not accompanied by vascular leakage, we investigated whether the osmotic swelling characteristics of retinal glial (Müller) cells are changed after experimental detachment of the porcine retina. Osmotic stress, induced by application of a hypotonic bath solution to retinal slices, caused swelling of Müller cell bodies in 7-day-detached retinas, but no swelling was inducible in slices of control retinas. Müller cell somata in slices of retinal areas that surround local detachment in situ also showed osmotic swelling, albeit at a smaller amplitude. The amplitude of osmotic Müller cell swelling correlated with the decrease in the K+ conductance, suggesting a causal relationship between both gliotic alterations. Further factors implicated in Müller cell swelling were inflammatory mediators and oxidative stress. We propose that a dysregulation of the ion and water transport through Müller cells may impair the fluid absorption from the retinal tissue, resulting in chronic fluid accumulation after detachment. This knowledge may lead to a better understanding of the mechanisms involved in retinal degeneration after detachment.

Müller cells as players in retinal degeneration and edema

BACKGROUND

Under normal conditions, Müller cells support neuronal activity and the integrity of the blood-retinal barrier, whereas gliotic alterations of Müller cells under pathological conditions may contribute to retinal degeneration and edema formation. A major function of Müller cells is the fluid absorption from the retinal tissue, which is mediated by transcellular water transport coupled to currents through potassium channels.

METHODS

Alterations of retinal Müller cells under pathological conditions were investigated by immunohistochemistry and recording their behavior under osmotic stress.

RESULTS

In animal models of various retinopathies, e.g., retinal ischemia, ocular inflammation, retinal detachment, and diabetes, it was found that Müller cells decrease the expression of their major potassium channel (Kir4.1). This alteration is associated with an impairment of the rapid water transport across Müller cell membranes, as recognizable in the induction of cellular swelling under hypoosmolar conditions. Osmotic swelling of Müller cells is also induced by oxidative stress and by inflammatory mediators such as arachidonic acid and prostaglandins.

CONCLUSIONS

The data suggest that a disturbed fluid transport through Müller cells is (in addition to vascular leakage) a pathogenic factor contributing to the development of retinal edema. Pharmacological re-activation of the retinal water clearance by Müller cells may represent an approach to the development of new edema-resolving drugs. Triamcinolone acetonide, which is clinically used to resolve edema, prevents osmotic swelling of Müller cells as it induces the release of endogenous adenosine and subsequent A1 receptor activation which results in the opening of ion channels. Apparently, triamcinolone resolves edema by both inhibition of vascular leakage and stimulation of retinal fluid clearance by Müller cells.

Vitreous fluid biomarkers

Interactions between cells and the network of secreted proteins are associated with the ocular disease. In most cases, clinical appearcance is sufficiently diagnostic. However, in cases of nonspecific or atypical clinical presentation, diagnostic sampling of vitreous fluid can aid diagnosis and treatment for ocular disease. Progresses in the basic sciences, particularly molecular biology, and advances in surgical instrumentation have greatly enhanced the diagnostic armamentarium. These developments also have led to a better understanding of the pathophysiological processes involved in ocular diseases and have prompted evolution of new therapeutic modalities. In this chapter, we review techniques for vitreous fluid sampling and biomarker quantitation thereof. The molecular biology of bioactive vitreous fluid factors is also discussed with respect to their clinical involvement in the development of ocular disease.