Abstract
Purpose: :
To evaluate the safety and efficacy of 0.5 mg versus 2.0 mg intravitreal ranibizumab in treatment naïve eyes with macular edema secondary to perfused central retinal vein occlusion.
Methods: :
Twenty patients (20 eyes) met eligibility criteria for this prospective investigator sponsored trial. Eligible eyes were randomized 1:1 to receive 3 initial monthly injections of either 0.5 mg or 2.0 mg ranibizumab followed by PRN retreatment was based on evidence of disease activity documented on spectral domain optical coherence tomography (SDOCT) (e.g., intraretinal fluid, subretinal fluid and/or cystic changes). The primary outcome measure was mean change in best-corrected visual acuity using the Early Treatment of Diabetic Retinopathy Study standardized and refracted visual acuity protocol. Secondary outcome measures include change in central subfield retinal thickness and number of treatments. Treating and evaluating physicians were masked to the treatment dose. Follow up period is 24 months with monthly SDOCT scans and quarterly fluorescein angiograms.
Results: :
At baseline, the mean visual acuity score was 49 letters and 56 letters and the mean central 1mm retinal thickness was 739 microns and 654 microns in the 0.5 mg and 2.0 mg groups respectively. After 3 months follow up, the mean visual acuity letter score increased from baseline by +23 letters and +19 letters; mean central subfield thickness decreased by -390 microns and -392 microns in the 0.5 mg and 2.0 mg groups respectively. At month 3, 50% (5/10) of the eyes in the 0.5 mg group required treatment compared to none in the 2.0 mg group. Between months 3 and 4, the mean change in visual acuity at month 4 was -9 letters and -8 letters; the mean change in central subfield retinal thickness increased by +111 microns and +252 microns in the 0.5 mg and 2.0 mg groups respectively. At Month 4, 80% (8/10) in the 0.5 mg group required treatment and 60% (6/10) needed additional injections in the 2.0 mg group. No drug-related serious systemic or ocular events were observed.
Conclusions: :
Following initial treatment with 0.5 mg or 2.0 mg intravitreal ranibizumab there were similar visual and anatomical changes in patients with macular edema due to CRVO. Fewer injections with 2.0 mg ranibizumab were needed during the retreatment period compared to 0.5 mg ranibizumab. However, both groups experienced decreased visual acuity and increased retinal thickening during the PRN retreatment period. Further studies and long-term follow up is needed to compare injection frequency between doses.
Clinical Trial: :
http://www.clinicaltrials.gov NCT01028248
Keywords: vascular occlusion/vascular occlusive disease • retina • vascular endothelial growth factor