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Anti-VEGF superior to observation, laser in eyes with central macular edema from BRVO
Significantly more patients who underwent observation required rescue laser treatment than those who received ranibizumab.
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Intravitreal ranibizumab improved vision and reduced central foveal thickness more than observation or grid laser treatment at 1 year in eyes with center-involved macular edema secondary to branch retinal vein occlusion, according to a study.
The results support intravitreal Lucentis (ranibizumab, Genentech) as the standard of care for center-involved macular edema associated with BRVO, according to Mei Hong Tan, MB ChB BAO, FRCOphth, PhD, the corresponding author.
“Based on the extent of improvement that is seen with intravitreal ranibizumab compared with grid laser treatment, it is clear that intravitreal anti-VEGF agents will form the mainstay of treatment for macular edema associated with BRVO,” Tan said in an email interview with Ocular Surgery News. “There is currently no other treatment that is as or more effective.”
The study was published in the American Journal of Ophthalmology.
Mei Hong Tan
Patients and methods
The prospective, randomized trial included 36 patients with vision loss in one eye from macular edema attributed to BRVO. A study group comprising 15 patients received six monthly injections of 0.5 mg ranibizumab and monthly as-needed injections. A control group of 21 patients underwent observation with six monthly sham injections followed by sham injections as needed.
Eligible patients in both groups underwent grid laser treatment at 13 weeks and 25 weeks.
Fourteen patients in the ranibizumab group and 16 patients in the control group completed the study.
Outcome measures included mean change in best corrected visual acuity from baseline to 12 months, central foveal thickness and percentage of patients requiring laser treatment.
Baseline BCVA was lower than in the BRAVO study, 39.5 letters vs. 56 letters, Tan said.
“This could indicate that our patient sample may represent more severe cases of venous occlusion where other factors such as ischemia and retinal hemorrhage have also contributed significantly to the visual impairment,” she said. “Consequently, this may have limited the extent of BCVA gain from baseline in both the intravitreal ranibizumab and grid laser groups.”
Results and observations
Patients in the ranibizumab group gained a mean 12.5 letters, and those in the control group lost a mean 1.6 letters. The between-group difference was statistically significant (P = .032).
Sixty percent of patients in the ranibizumab group and 28.6% of controls had BCVA of 20/40 or better at 12 months. One patient in the control group (4.8%) and no patients in the ranibizumab group had BCVA of 20/200 or worse.
Mean central foveal thickness decreased 361.7 µm in the ranibizumab group and 175.6 µm in the control group; the between-group difference was statistically significant (P = .025).
At 25 weeks, one of 12 patients (8.3%) in the ranibizumab group and eight of 16 patients (50%) in the control group required laser treatment. The difference was statistically significant (P = .039).
Collateral vessels were identified in nine of 14 patients (64%) in the ranibizumab group and eight of 16 patients (50%) in the laser group at 1 year.
“The development of collateral vessels and vascular modeling usually occurs several months after the initial venous obstruction, and this can have an effect on the resolution of macular edema,” Tan said. “It would therefore be important to allow adequate time for these factors to develop in order to fully assess the effect of a particular treatment. This is why this study provides direct comparison of the efficacy of intravitreal ranibizumab vs. grid laser in treating macular edema following BRVO, as there is no crossover between treatments for the whole duration of the study.”
Further study of the frequency and duration of anti-VEGF therapy is warranted, Tan said.
“The burden and risks of repeated injections need to be taken into consideration, especially since it is currently unclear where the endpoint for injections lies. Longer-term studies will bear more light on this, and future work will be directed at addressing this issue,” she said. – by Matt Hasson