The purpose of this study was to compare inner retinal thickness and retinal nerve fiber layer (RNFL) thickness between fellow eyes with unilateral branch retinal vein occlusion (BRVO) and normal control eyes.

Retrospective cross-sectional study including 59 patients diagnosed with unilateral BRVO and 51 control subjects. Using spectral domain optical coherence tomography, we investigated the average, 4 quadrant, and 12 clock-hour RNFL thicknesses and the average, minimum, superior, superonasal, superotemporal, inferior, inferonasal, and inferotemporal thicknesses of the ganglion cell-inner plexiform layer (GCIPL) layer.

Patients with unilateral BRVO had a higher incidence of hypertension. In the fellow eyes of the unilateral BRVO patients, 7 and 11 o'clock RNFL thicknesses were significantly thinner than for the control eyes. There was no significant difference in the GCIPL thickness between the two groups

The RNFL thickness of the fellow eyes of the unilateral BRVO patients showed significant decreases in the 7 and 11 o'clock sectors ( p =0.005, 0.017, respectively), whereas there was no significant difference in the GCIPL thickness between the two groups. In the RNFL thickness analysis, the 7 and 11 o'clock sectors were found to be dominant locations of decreased RNFL thickness for the open angle glaucoma. Further, glaucomatous change should be carefully monitored in the fellow eyes of unilateral BRVO patients.