Clinical and angiographic features in nasal branch retinal vein occlusion

Purpose: To analyse the epidemiological and clinical characteristics of nasal branch retinal vein occlusion (NBRVO). Methods: Patients affected by branch retinal vein occlusion observed in the out-patient departments of the Eye Clinic of Trieste between January 1995 and January 1999 were enrolled. Results: Out of 144 patients with branch retinal vein occlusion, 128 (88.9%) were affected by temporal branch retinal vein occlusion (TBRVO), and 16 patients were affected by NBRVO (11.1%). The two groups did not differ as far as systemic hypertension, diabetes mellitus, glaucoma and ischaemic heart disease were regarded. NBRVO cases were characterized by better visual acuity and greater figures of capillary non-perfusion, retinal neovascularization and vitreous haemorrhage. Conclusions: NBRVO, even though infrequent, shares the same epidemiological characteristics as TBRVO. The higher prevalence of ischaemic cases in the NBRVO group could depend on a bias during the enrolment of patients, because especially symptomatic patients may have been examined in our out-patient departments. The relatively high percentage of epiretinal membrane formation after laser photocoagulation suggests particular caution, especially in cases presenting with vitreous haemorrhage.