Gulnar Hafiz

Ranibizumab for macular edema due to retinal vein occlusions: implication of VEGF as a critical stimulator.

Macular edema is a major cause of vision loss in patients with central retinal vein occlusion (CRVO) or branch retinal vein occlusion (BRVO). It is not clear how much of the edema is due to hydrodynamic changes from the obstruction and how much is due to chemical mediators. Patients with macular edema due to CRVO (n = 20) or BRVO (n = 20) were randomized to receive three monthly injections of 0.3 or 0.5 mg of ranibizumab. At the primary endpoint, month 3, the median improvement in letters read at 4 m was 17 in the 0.3-mg group and 14 in the 0.5-mg group for CRVO, and 10 and 18, respectively for the BRVO group. Optical coherence tomography (OCT) showed that compared to injections of 0.3 mg, injections of 0.5 mg of ranibizumab tended to cause more rapid reductions of central retinal thickening that lasted longer between injections, but in 3 months, excess central retinal thickening which is a quantitative assessment of the macular edema, was reduced by approximately 90% in all four treatment groups. There was no correlation between the amount of improvement and duration of disease or patient age at baseline, but there was some correlation between the aqueous vascular endothelial growth factor (VEGF) level at baseline and amount of improvement. These data indicate that excess production of VEGF in the retinas of patients with CRVO or BRVO is a major contributor to macular edema and suggest that additional studies investigating the efficacy of intraocular injections of ranibizumab are needed.

Sustained Ocular Delivery of Fluocinolone Acetonide by an Intravitreal Insert

PURPOSE To compare Iluvien intravitreal inserts that release 0.2 or 0.5 microg/day of fluocinolone acetonide (FA) in patients with diabetic macular edema (DME). DESIGN Prospective, randomized, interventional, multicenter clinical trial. PARTICIPANTS We included 37 patients with DME. METHODS Subjects with persistent DME despite > or = 1 focal/grid laser therapy were randomized 1:1 to receive an intravitreal insertion of a 0.2- or a 0.5-microg/day insert. MAIN OUTCOME MEASURES The primary end point was aqueous levels of FA throughout the study with an important secondary outcome of the change from baseline in best-corrected visual acuity (BCVA) at month 12. RESULTS The mean aqueous level of FA peaked at 3.8 ng/ml at 1 week and 1 month after administration of a 0.5-microg/day insert and was 3.4 and 2.7 ng/ml 1 week and 1 month after administration of a 0.2-microg/day insert. For both inserts, FA levels decreased slowly thereafter and were approximately 1.5 ng/ml for each at month 12. The mean change from baseline in BCVA was 7.5, 6.9, and 5.7 letters at months 3, 6, and 12, respectively, after administration of a 0.5 microg/day-insert and was 5.1, 2.7, and 1.3 letters at months 3, 6, and 12, respectively, after administration of a 0.2-microg/day insert. There was a mild increase in mean intraocular pressure after administration of 0.5-microg/day inserts, but not after administration of 0.2-microg/day inserts. CONCLUSIONS The FA intravitreal inserts provide excellent sustained intraocular release of FA for > or = 1 year. Although the number of patients in this trial was small, the data suggest that the inserts provide reduction of edema and improvement in BCVA in patients with DME with mild effects on intraocular pressure over the span of 1 year. FINANCIAL DISCLOSURE(S) Proprietary or commercial disclosure may be found after the references.

Antagonism of vascular endothelial growth factor for macular edema caused by retinal vein occlusions: two-year outcomes.

PURPOSE To determine the long-term effects of intraocular antagonism of vascular endothelial growth factor (VEGF) in patients with macular edema caused by retinal vein occlusions (RVOs). DESIGN Prospective randomized trial. PARTICIPANTS Twenty patients with macular edema caused by branch RVOs (BRVOs) and 20 patients with central RVOs (CRVOs). METHODS After the month 3 primary end point, patients were seen every 2 months and received injections of an anti-VEGF agent as needed for recurrent edema. MAIN OUTCOME MEASURES Mean change from baseline best-corrected visual acuity (BCVA) at month 24 with assessment of other parameters of visual function and center subfield thickness (foveal thickness [FTH]). RESULTS For 17 patients with BRVO who completed 2 years of follow-up, the mean improvement from baseline in BCVA at month 24 was 17.8 letters compared with 15.6 letters at month 3. Improvement by at least 6, 3, or 2 lines occurred in 18%, 59%, and 76% of patients, respectively. The Snellen equivalent BCVA at month 24 was 20/40 or better in 10 patients. With an average of 2 injections of ranibizumab during year 2, the mean FTH at month 24 was 245.8 μm compared with 217.1 μm at month 3 and 481.5 μm at baseline. For 14 patients with CRVO who completed 2 years of follow-up, the mean improvement in BCVA at month 24 was 8.5 letters compared with 12.0 letters at month 3. Improvement by at least 6, 3, or 2 lines occurred in 14%, 21%, and 43% of patients, respectively. The Snellen equivalent BCVA at month 24 was 20/40 or better in 4 patients. With an average of 3.5 injections of ranibizumab in year 2, mean FTH at month 24 was 338 μm compared with 278 μm at month 3 and 533 μm at baseline. Duration of RVO >1 year at study entry and nonperfusion of perifoveal capillaries for 360 degrees correlated with reduced visual outcomes. CONCLUSIONS Antagonism of VEGF provides substantial long-term benefit to patients with macular edema caused by RVO, but frequent injections are required in some patients with BRVO and most patients with CRVO.

Monitoring Ocular Drug Therapy by Analysis of Aqueous Samples

OBJECTIVE To assess the value of sampling aqueous humor for measurement of potential molecular targets and for pharmacokinetic analysis. DESIGN Substudy within the context of clinical trials. PARTICIPANTS Forty patients with macular edema caused by central retinal vein occlusion (CRVO) or branch retinal vein occlusion (BRVO), 11 patients with diabetic macular edema (DME), and 8 patients with neovascular age-related macular degeneration (NVAMD). METHODS Assays for potential molecular targets were performed on aqueous samples from patients participating in drug studies (CRVO, BRVO, and DME) or patients receiving standard care (NVAMD). Ranibizumab levels were measured in patients with CRVO or BRVO after the first and second injections of ranibizumab. MAIN OUTCOME MEASURES Aqueous levels of vascular endothelial growth factor (VEGF), interleukin (IL)-6, IL-1beta, tumor necrosis factor (TNF)-alpha, and ranibizumab. RESULTS Aqueous levels of VEGF were significantly higher in patients with DME than in patients with CRVO, which were significantly higher than those in patients with BRVO. Patients with NVAMD had aqueous VEGF levels in an intermediate range, significantly higher than those in patients with BRVO. One month after the second injection of ranibizumab, 27 of 39 patients with vein occlusions had no residual edema; mean aqueous levels of IL-6, IL-1beta, and TNF-alpha were not greater in patients with residual edema; this provides a blueprint for definitive studies with larger cohorts. There was no significant difference in aqueous ranibizumab levels 1 month after the first injection of 0.5 mg versus injection of 0.3 mg, but 1 month after the second injection ranibizumab levels were significantly higher in eyes injected with 0.5 mg. There were substantial differences in levels among patients, but levels in the same patient at months 1 and 2 were highly correlated. No significant difference in aqueous ranibizumab levels was detected between phakic and pseudophakic patients who received the same dose. CONCLUSIONS These data suggest that aqueous samples are useful for investigating potential involvement of molecular targets in various disease processes and for pharmacokinetic or pharmacodynamic studies.

Aqueous Levels of Fluocinolone Acetonide after Administration of Fluocinolone Acetonide Inserts or Fluocinolone Acetonide Implants

PURPOSE To compare aqueous levels of fluocinolone acetonide (FAc) after administration of FAc inserts or FAc implants (Retisert; Bausch & Lomb, Rochester, NY). DESIGN Comparison of pharmacokinetics from 2 prospective, interventional, clinical trials. PARTICIPANTS Thirty-seven patients with diabetic macular edema (DME) (Fluocinolone Acetonide in Human Aqueous [FAMOUS] Study, C-01-06-002) and 7 patients with uveitis (NA-00019318). METHODS Aqueous FAc was measured after administration of FAc implants or 0.2 μg/day (low dose, ILUVIEN; Alimera Sciences Inc., Alpharetta, GA) or 0.5 μg/day (high dose) FAc inserts. MAIN OUTCOME MEASURES The primary end point was aqueous levels of FAc. RESULTS At 1 month after administration for subjects who received 1 treatment, mean aqueous FAc levels were 2.17 (low dose) and 3.03 ng/ml (high dose) for FAc inserts and 6.12 ng/ml for FAc implants with maximum levels of 3.83, 6.66, and 13.50 ng/ml, respectively. At 3 months, mean FAc levels were 1.76, 2.15, and 6.12 ng/ml, respectively. Between 6 and 36 months after low-dose inserts, aqueous levels of FAc were remarkably stable, ranging from 1.18 to 0.45 ng/ml. After high-dose inserts, mean FAc levels were stable between 6 and 24 months, ranging from 1.50 to 0.84 ng/ml and then decreasing to 0.35 ng/ml at 30 months and 0.15 ng/ml at 36 months. In implant-containing eyes, mean FAc levels remained >6 ng/ml through 15 months, the last time point with measurements from at least 6 eyes. CONCLUSIONS Low- and high-dose FAc inserts both provide stable long-term release of FAc with comparable peak levels in the aqueous: slightly >2 ng/ml for approximately 3 months followed by steady-state levels between 1.0 and 0.5 ng/ml through 36 months for low-dose inserts versus levels between 1.5 and 1.1 ng/ml through 24 months for high-dose inserts. Steady-state aqueous levels after FAc implants were >6 ng/ml. These results provide new insights that aid in the interpretation of efficacy trials and indicate that there is a dose effect for steroid-induced ocular hypertension. In susceptible patients, prolonged aqueous levels of FAc >1 ng/ml moderately increased the risk of glaucoma and levels >6 ng/ml posed a markedly increase risk.

Scatter Photocoagulation Does Not Reduce Macular Edema or Treatment Burden in Patients with Retinal Vein Occlusion The RELATE Trial

PURPOSE To determine whether scatter and grid laser photocoagulation (laser) adds benefit to ranibizumab injections in patients with macular edema from retinal vein occlusion (RVO) and to compare 0.5-mg with 2.0-mg ranibizumab. DESIGN Randomized, double-masked, controlled clinical trial. PARTICIPANTS Thirty-nine patients with central RVO (CRVO) and 42 with branch RVO (BRVO). METHODS Subjects were randomized to 0.5 mg or 2.0 mg ranibizumab every 4 weeks for 24 weeks and re-randomized to pro re nata ranibizumab plus laser or ranibizumab alone. MAIN OUTCOME MEASURES Mean change from baseline best-corrected visual acuity (BCVA) at week 24 for BCVA at weeks 48, 96, and 144 for second randomization. RESULTS Mean improvement from baseline BCVA at week 24 was 15.5 and 15.8 letters in the 0.5-mg and 2.0-mg CRVO groups, and 12.1 and 14.6 letters in the 0.5-mg and 2.0-mg BRVO groups. For CRVO, but not BRVO, there was significantly greater reduction from baseline mean central subfield thickness (CST) in the 2.0-mg versus 0.5-mg group (396.1 vs. 253.5 μm; P = 0.03). For the second randomization in CRVO patients, there was no significant difference from week 24 BCVA in the ranibizumab plus laser versus the ranibizumab only groups at week 48 (-3.3 vs. 0.0 letters), week 96 (+0.69 vs. -1.6 letters), or week 144 (+0.4 vs. -6.7 letters), and a significant increase from week 24 mean CST at week 48 (+94.7 vs. +15.2 μm; P = 0.05) but not weeks 96 or 144. For BRVO, there was a significant reduction from week 24 mean BCVA in ranibizumab plus laser versus ranibizumab at week 48 (-7.5 vs. +2.8; P < 0.01) and week 96 (-2.0 vs. +4.8; P < 0.03), but not week 144, and there were no differences in mean CST change from week 24 at weeks 48, 96, or 144. Laser failed to increase edema resolution or to reduce the ranibizumab injections between weeks 24 and 144. CONCLUSIONS In patients with macular edema resulting from RVO, there was no short-term clinically significant benefit from monthly injections of 2.0-mg versus 0.5-mg ranibizumab injections and no long-term benefit in BCVA, resolution of edema, or number of ranibizumab injections obtained by addition of laser treatment to ranibizumab.

Is There Excess Oxidative Stress and Damage in Eyes of Patients with Retinitis Pigmentosa

Retinitis pigmentosa (RP) is a group of diseases in which a mutation in one of the large variety of genes causes death of rod photoreceptors. After rods die, cone photoreceptors gradually die resulting in constriction of visual fields and eventual blindness in many patients. Studies in animal models of RP have demonstrated that oxidative damage is a major contributor to cone cell death. In this study, we extended those findings to patients with RP, because compared to control patients, those with RP showed significant reduction in the reduced to oxidized glutathione (GSH/GSSG) ratio in aqueous humor and a significant increase in aqueous protein carbonyl content. In contrast, there was no significant decrease in the serum GSH/GSSG ratio or increase in carbonyl content of serum proteins. These data indicate that patients with RP have ocular oxidative stress and damage in the absence of manifestations of systemic oxidative stress and/or damage indicating that demonstrations of oxidative damage-induced cone cell death in animal models of RP may translate to human RP. These observations lead to the hypothesis that potent antioxidants will promote cone survival and function in patients with RP and that the aqueous GSH/GSSG ratio and carbonyl content on proteins may provide useful biomarkers. Antioxid. Redox Signal. 23, 643-648.

Long-term Outcomes in Ranibizumab-Treated Patients With Retinal Vein Occlusion; The Role of Progression of Retinal Nonperfusion

PURPOSE To determine the percentage of ranibizumab-treated patients with retinal vein occlusion (RVO) who had resolution of edema for at least 6 months after the last injection, along with factors and outcomes that correlate with resolution. DESIGN Post hoc analysis of open-label clinical trial. METHODS Twenty patients with branch RVO (BRVO) and 20 with central RVO (CRVO) received ranibizumab monthly for 3 months and as needed for recurrent/persistent macular edema, no more frequently than every 2 months. Patients still requiring injections after month 40 received scatter and grid laser photocoagulation to try to reduce the need for injections. Main outcome measures included the percentage of patients who had resolution of edema, change in best-corrected visual acuity (BCVA) from baseline, and change in area of retinal nonperfusion in central subfields. RESULTS Nine patients with BRVO (45%) had edema resolution from injections alone after a mean of 20.2 months, 4 resolved after addition of laser, 4 were unresolved through 72 months, and 3 exited prior to resolution. Five patients with CRVO (25%) resolved from injections alone after a mean of 14.0 months, 8 remained unresolved through 72 months despite addition of laser, and 7 exited prior to resolution. For BRVO or CRVO, there was a negative correlation between posterior retinal nonperfusion area and BCVA at months 18, 24, and 36 (P < .05). CONCLUSIONS In patients with RVO, infrequent ranibizumab injections to control edema may not be sufficient to prevent progression of retinal nonperfusion, which may contribute to loss of visual gains.

Topical Mecamylamine for Diabetic Macular Edema

PURPOSE Stimulation of nicotinic acetylcholine (nACh) receptors on vascular endothelial cells promotes angiogenesis and vascular permeability in animal models. The safety and bioactivity of topical mecamylamine, an antagonist of nACh receptors, was tested in patients with diabetic macular edema. DESIGN A multicenter phase I/II clinical trial. METHODS Twenty-three patients with chronic diabetic macular edema received 1% mecamylamine topically twice daily for 12 weeks, the primary end point. Patients underwent safety assessments, measurement of best-corrected visual acuity (BCVA), and measurement of foveal thickness using optical coherence tomography at baseline, 1, 4, 8, 12, and 16 weeks. RESULTS Mecamylamine drops were well tolerated and there were no drug-related safety problems. Mean improvement in BCVA at 1, 4, 8, 12, and 16 weeks was 2.8, 1.9, 2.4, 0.8, and 3.1 letters, respectively. There was little change in mean excess foveal thickness. There was substantial heterogeneity in response, because 8 patients showed convincing improvement in BCVA, foveal thickness, or both, 9 patients showed equivocal or no substantial changes, and 4 patients showed worsening. Five patients showed a substantial improvement in BCVA, foveal thickness, or both between their last visit while receiving mecamylamine and 1 month after stopping mecamylamine. CONCLUSIONS This study suggested that administration of topical mecamylamine, a nonspecific nACh receptor blocker, may have heterogeneous effects in patients with diabetic macular edema. Variable expression of nACh receptor subtypes on endothelial cells that have different effects on permeability would provide an explanation for these results and should be investigated, because more specific nACh receptor blockers may dissociate antipermeability and propermeability effects.

Interleukin-18 Has Antipermeablity and Antiangiogenic Activities in the Eye: Reciprocal Suppression With VEGF

Interleukin‐18 (IL‐18) is increased along with IL‐1β by activation of the inflammasome and has been implicated in inflammatory and autoimmune diseases, but its role in the eye is uncertain. In patients with macular edema due to retinal vein occlusion, intraocular IL‐18 levels increased significantly (P < 0.001) after treatment with ranibizumab particularly in patients with high baseline IL‐18 which correlated with good visual outcome (P < 0.05). In mice with ischemic retinopathy, suppression of VEGF caused an increase in IL18 mRNA due to an increase in IL‐18‐positive myeloid cells. VEGF significantly and specifically inhibited IL‐18 production by myeloid cells stimulated with lipopolysaccharide (P < 0.001). Intraocular injection of IL‐18 reduced VEGF‐induced leakage and neovascularization, and reversed VEGF‐induced suppression of Claudin5 expression and Claudin 5 labeling of vascular tight junctions. Injection of IL‐18 also increased expression of Thrombospondin 1 and reduced ischemia‐induced retinal neovascularization relevant to diabetic retinopathy and subretinal neovascularization relevant to neovascular age‐related macular degeneration. Thus, VEGF and IL‐18 suppress each others production and effects on the vasculature suggesting that IL‐18 may provide benefit in multiple retinal/choroidal vascular diseases. J. Cell. Physiol. 229: 974–983, 2014.