Grid laser treatment in macular branch retinal vein occlusion.

Background: Macular branch retinal vein occlusion (MBRVO) is a subgroup of branch retinal vein occlusion in which the occlusion is limited to a small venous vessel draining a sector of the macular region. The present study aimed to evaluate prospectively whether grid laser treatment is useful in improving the visual acuity of eyes affected by MBRVO with significant macular edema.
Methods: Ninety-nine patients affected by MBRVO of recent onset were prospectively studied during a 24-month period; eyes were randomly assigned to the control group, the early grid laser treatment group or the delayed grid laser treatment group. Clinical and angiographic features were recorded during the whole follow-up; parameters such as visual acuity and macular edema were carefully evaluated, the latter even by means of stereophotography.
Results: With respect to the baseline mean visual acuity values, a statistically significant improvement was noted at the 3-month follow-up and at the 1-year follow-up. No additional improvement was noted at the 2-year follow-up. No statistically significant difference was found between the treated groups and the control group.
Conclusions: We hypothesize that the abrupt ischemic damage subsequent to MBRVO is the main factor causing the central function impairment. Grid laser treatment is not able to reduce the macular edema more than the natural evolution, and does not improve visual acuity.