Gelareh Abedi

Bevacizumab vs Ranibizumab for Age-Related Macular Degeneration: Early Results of a Prospective Double-Masked, Randomized Clinical Trial

PURPOSE To report early outcomes of a prospective, double-masked, controlled trial comparing bevacizumab (Avastin; Genentech Inc, South San Francisco, California, USA) to ranibizumab (Lucentis; Genentech Inc) for the treatment of age-related macular degeneration. DESIGN Prospective, double-masked, randomized clinical trial. METHODS This is a single-center, randomized clinical trial at the Boston Veterans Affairs Healthcare System. Patients who met inclusion criteria were randomized 2:1 to bevacizumab or ranibizumab. Each patient contributed 1 eye to the study. All subjects and investigators (except for the pharmacist responsible for study assignments) were masked to treatment arms. Visual acuity (VA) was checked on Early Treatment Diabetic Retinopathy Study (ETDRS) chart. Patients were given either bevacizumab or ranibizumab every month for the first 3 months, followed by optical coherence tomography-guided, variable-dosing schedule. Main outcomes measured were VA and foveal thickness. RESULTS Twenty patients completed the 6-month follow up. Thirteen patients received bevacizumab and 7 patients received ranibizumab. No subjects in either group lost more than 15 letters on ETDRS chart. The average preoperative VA was 31.6 letters in the bevacizumab group and 30.4 letters in the ranibizumab group. At 6 months follow-up, mean vision was 46.4 letters in the bevacizumab group and 37.4 letters in the ranibizumab group. Two-tailed ttest failed to show statistical significance between the two groups. Patients in the bevacizumab group underwent an average of 5 injections, while patients in the ranibizumab group underwent a mean of 4 injections. CONCLUSION Early results of a head-to-head, randomized, double-masked, prospective, single-center controlled trial between bevacizumab and ranibizumab show no difference in efficacy between the two treatments for choroidal neovascularizaton in the treatment of age-related macular degeneration. As this study conveys results of a small number of patients, further studies with larger sample sizes are needed in order to establish statistical significance.

Bevacizumab vs ranibizumab for age-related macular degeneration: 1-year outcomes of a prospective, double-masked randomised clinical trial

PurposeTo report 1-year visual and anatomic outcomes of a prospective, double-masked randomised clinical trial comparing bevacizumab with ranibizumab for the treatment of age-related macular degeneration (AMD).MethodsPatients who met inclusion criteria were randomised 2 : 1 to bevacizumab or ranibizumab. All subjects and investigators (except for the pharmacist responsible for study assignments) were masked to treatment arms. Visual acuity was taken on Early Treatment Diabetic Retinopathy Study chart. Patients were given either bevacizumab or ranibizumab every month for the first 3 months, followed by an optical coherence tomography-guided, variable-dosing treatment schedule. Main outcomes measured included visual acuity, foveal thickness, and total number of injections over the 1-year treatment period.ResultsIn total, 15 patients received bevacizumab and 7 patients received ranibizumab. The average pre-operative visual acuity was 34.9 letters in the bevacizumab group, and 32.7 letters in the ranibizumab group. At 1-year follow-up, mean vision was 42.5 letters in the bevacizumab group, and 39.0 letters in the ranibizumab group. Two-tailed t-test failed to showed statistical significance between the two groups (P=0.5). Patients in the bevacizumab group underwent an average of eight injections, whereas patients in the ranibizumab group underwent a mean of four injections (P=0.001).ConclusionThe 1-year outcomes of a prospective, double-masked, randomised clinical trial comparing bevacizumab with ranibizumab failed to show a difference in visual and anatomic outcomes between the two treatments for choroidal neovascularisation in AMD. Total injections given over the treatment period were significantly different between the two groups. Further studies with larger sample sizes are warranted.

Incidence and Management of Elevated Intraocular Pressure with Antivascular Endothelial Growth Factor Agents

Abstract Purpose: To review recent literature regarding ocular hypertension following intravitreal antivascular endothelial growth factors (anti-VEGF). Method: An electronic literature search was performed using MEDLINE, OVID, and PubMed. Key search terms were elevated IOP, anti-VEGF, sustained IOP elevation in anti-VEGF, chronic intraocular pressure elevation in anti-VEGF, high IOP with anti-VEGF, acute elevation in intraocular pressure with anti-VEGF, glaucoma and anti-VEGF. Result: Transient elevation of intraocular pressure after intravitreal anti-VEGF injection is due to temporary increase in volume, and the acute spike generally does not affect a healthy eye. Caution should be taken in a glaucomatous eye, and pretreatment with an IOP-lowering medication is recommended. Persistent elevation of intraocular pressure is more common than previously thought and may be correlated to several factors including increased number of intravitreal injections. Conclusion: Persistent ocular hypertension may be associated with intravitreal anti-VEGF injections. Physicians should be aware of this condition and monitor their patients for persistent ocular hypertension, especially in eyes with preexisting glaucoma. Prompt diagnosis and treatment can prevent potential loss of vision.

Transitioning from Stratus OCT to Cirrus OCT using Lin's concordance coefficient.

Dear Editor, We thank Drs. Tan and Li for their valuable comments on our original paper [1]. The purpose of our paper was to study the differences between central subfield macular thickness (CSMT) measurements obtained by time-domain Stratus optical coherence tomography (OCT) and Cirrus spectral-domain OCT (Carl Zeiss Meditec, Dublin, CA, USA) and to propose a method for deriving an equation to convert CSMT values from one to the other. Our method proposes to derive a linear transformation by maximizing the Lin’s concordance coefficient [2] between the CSMT measurements obtained by time-domain Stratus OCT and Cirrus spectral domain OCT rather then using simple regression. Lin’s concordance correlation coefficient evaluates the degree to which pairs of observations fall on the 45° line through the origin, and thus a transformation that maximizes this concordance measure is more appropriate for our purpose. We obtained the linear transformation 0.76 × −0.51, which proved to work very well for our practice. Unfortunately, our study was retrospective, and at the time of our study we had a limited number of eyes on both machines. Since the data was very limited, we decided to use all data points to estimate our formula more accurately. We did not have the option to get more data, as one of the machines had been retired. We thank the authors for highlighting this shortcoming with our method. We agree with the authors that using an independent sample for validation will more likely lead to a more robust equation. In their letter [3], the authors use regression to derive a linear transformation and then point out that the intra-class correlation (ICC) between the two measures is higher on the data used for deriving the equation (fit data) than on the independent data (validation data). This is expected, as the equation was estimated on the fit data. If we were aware of the differences between the two machines we would have designed the study in a more optimal way. One method that might avoid the problem mentioned by Drs. Tan and Li would be to create several splits of the data and estimate a separate equation for each split, and then average over the equations. Note that this method does require more data, which we did not have. We do hope that our paper will contribute to raising awareness of this problem in the ophthalmology community, so that physicians can use the methods discussed in [1, 3] G. Abedi (*) Vitreoretinal Disease and Surgery, University of Texas Health Science Center, San Antonio, 7703 Floyd Curl Drive, MC 6230, San Antonio, TX 78229-3900, USA e-mail: abedig@uthscsa.edu

The role of intravenous immunoglobulin in treatment of acute retinal necrosis.

PURPOSE To describe a case of successful treatment of acute retinal necrosis with a combination of antivirals and intravenous immunoglobulin. METHODS This is a case report of a 77-year-old white man diagnosed with unilateral acute retinal necrosis. RESULTS Combination therapy with systemic antivirals, prophylactic laser retinopexy, and intravenous immunoglobulin halted progression of retinitis and preserved visual acuity. CONCLUSION Acute retinal necrosis is an aggressive disease with significant risk of vision loss even when treated with appropriate therapy. In this report, the authors describe a case of successful treatment with a combination of systemic antivirals and intravenous immunoglobulin. Intraocular antiviral injection plus systemic treatment remain to be a more cost-effective option.