Optical quality assessment in branch retinal vein occlusion after monthly intravitreal ranibizumab injection: a...

To evaluate optical quality and intraocular scattering using the Optical Quality Analysis System (OQAS) II in branch retinal vein occlusion (BRVO) and to investigate the influences of retinal changes on optical quality.

Sixty-two patients with diagnosis of BRVO were enrolled in this prospective, case-control study. The control group consisted of the patients' fellow eyes. Initial logMAR visual acuity, central macular thickness, and optical quality parameters including modulation transfer function cutoff frequency (MTF cut off), Strehl ratio (SR), objective scatter index (OSI) and OQAS values (OVs) at 100%, 20%, and 9% contrast levels were measured. Every BRVO-affected eye was treated with monthly intravitreal ranibizumab injection. We investigated the differences between clinical parameters of the BRVO-affected eye and those of the control eye and changes in those parameters on the basis of the clinical course of BRVO over 3 months.

All the OQAS parameters measured except objective refraction error differed statistically significantly between the two groups. As macular thickness decreased and visual acuity improved, all the optical quality parameters except for objective refraction error and OV at 100% contrast gradually recovered with time after treatment but did not return to normal compared with the control eye. Only visual acuity was found to be significantly related to central macular thickness change (p = .027).

BRVO resulted in declined visual acuity and optical quality. It is suggested that the optical quality parameters are affected by the inner layers of the retina in BRVO.