Transient increase in macular edema following vitrectomy for retinal branch vein occlusion.

Purpose: We confirmed a transient increase in macular edema in some patients after simple vitrectomy for macular edema associated with branch retinal vein occlusion (BRVO).

Methods: We studied 54 consecutive patients (54 eyes) with macular edema secondary to BRVO and preoperative visual acuity of 0.5 or below, who underwent vitrectomy and were followed for at least 1 year. Visual acuity and foveal retinal thickness measured by optical coherence tomography were determined before and after vitrectomy.

Results: The patients were divided into two groups according to whether there was a postoperative increase in foveal retinal thickness. In group A (11 eyes; 20.3%), a significant increase in foveal retinal thickness was observed at 1 month after surgery, but there was no significant change in visual acuity. In group B (43 eyes; 79.6%), there was no transient increase in retinal thickness, and visual acuity improved while foveal retinal thickness decreased gradually by 1 year after surgery. In group A, macular edema had improved significantly at 3 months after surgery without local injection of triamcinolone acetonide (TA), and visual acuity and foveal retinal thickness at 1 year after surgery did not differ significantly from those in group B. Multiple regression analysis was conducted to identify the preoperative factors associated with transient increase in macular edema, and no significant factor was detected.

Conclusions: When simple vitrectomy is conducted for macular edema associated with BRVO, a transient postoperative increase in macular edema occurs in some cases, but resolves spontaneously without TA injection. Further study is required to determine whether this transient increase in macular edema is a phenomenon that occurs after vitrectomy for diseases accompanied by macular edema.