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[Efficiency of surgical treatment for chronic macular edema due to branch retinal vein occlusion].

INTRODUCTION
Internal limiting membrane peeling has recently given interesting results in the management of macular edema in diabetic patients, even in the absence of vitreomacular tractions. This study was conducted to evaluate the results of a surgical treatment for macular edema resulting from branch retinal vein occlusion.


MATERIAL AND METHODS
A nonrandomized prospective study was conducted between March 2001 and April 2002 on 12 eyes of 12 consecutive patients with a visual acuity of 20/40 or less resulting from branch retinal vein occlusion with macular edema. Internal limiting membrane peeling associated with arteriovenous crossing sheathotomy was performed on six eyes and internal limiting membrane peeling alone was performed on six eyes. Patients were tested with ETDRS visual acuity, fluorescein angiography, automated perimetry, and OCT pre- and postoperatively (at 3 and 6 months).


RESULTS
At 6 months, postoperative visual acuity was improved in all patients (mean VA=20/40; range, 20/125-20/20), with an average gain of three lines of vision (or 14 ETDRS points) (p=0.002). Fundus examination and fluorescein angiography results were improved in all patients. At 6 months, on automated field testing, the mean corrected defect improved from 3.4+/-0.9dB to 2.3+/-0.9dB (p=0.008). On OCT, mean foveal thickness decreased from 419+/-57 micro m to 233+/-10 micro m (p=0.02). No difference was noted between simple vitrectomy with internal limiting membrane peeling and arteriovenous crossing sheathotomy in terms of visual acuity (p=0.5), visual field (p=0.2), or foveal thickness (p=0.6) improvement.


CONCLUSION
Our findings suggest that internal limiting membrane removal for macular edema may improve the functional prognosis in patients with branch retinal vein occlusion. Adventitial sheathotomy did not yield further functional benefits in these cases.