BRANCH RETINAL VEIN OCCLUSION AND MACROANEURYSMS

Background: Macroaneurysms can represent common consequences of branch retinal vein occlusion (BRVO). The aim of the present study is to eva luate the clinical and angiographic aspects of 31 cases of branch reti nal vein occlusions (BRVO) in which retinal macroaneurysms developed, in an attempt to analyze their pathogenic features. Methods: One hundr ed and sixty-one consecutive patients affected by BRVO were considered . Each patient underwent an ophthalmological examination including flu orescein angiography, at an average interval of two months (range: 1-4 months) from the onset of the disease, with a mean follow-up of 43 mo nths (range: 32-56 months). The macroaneurysms were subdivided accordi ng to size into small (from 100 to 149 microns), medium (from 150 to 2 49 microns), and large (greater than 250 microns), and according to or igin into arterial, venous, capillary and collateral-associated. Resul ts: Thirty-one patients (19.3%) developed retinal macroaneurysms. The total number of detected macroaneurysms was 51; ten (19.6%) were large , 21 (41.2%) were of medium-size and 20 (39.2%) were small in dimensio n. Three lesions were of arterial origin, 22 were capillary and 26 wer e from collateral vessels. In 27 patients (87.1%) the lesions were loc ated outside the macular region, and in 4 patients (12.9%) in the macu lar region. Patients with retinal macroaneurysms did not show a differ ent prevalence of capillary non-perfusion when compared with others. W ith regard to the number of retinal venous collaterals patients with m acroaneurysms developed fewer than other patients, and the difference was statistically significant (p < 0.001). Conclusion: The insufficien t number of retinal venous collaterals can be considered the most cont ributory factor in the development of macroaneurysms secondary to BRVO .