Predicting the visual acuity for retinal vein occlusion after ranibizumab therapy with an original ranking for macular microstructure

Abstract

The study investigated predictive factors for best-corrected visual acuity (BCVA) after ranibizumab treatment in patients with macular edema (ME) associated with retinal vein occlusion (RVO) with an original ranking for the impairment of macular microstructure. In this retrospective study, 31 eyes of 31 patients with RVO received 3 monthly consecutive ranibizumab injections and another 3 months of follow-up. An original method was applied to rank the impairment of the external limiting membrane (ELM) and the ellipsoid zone (previously called the photoreceptor inner and outer segment junction, IS/OS) integrity on the baseline optical coherence tomography (OCT) images. Univariate and multivariate linear regression analyses were performed to assess the association between the baseline factors and post-treatment BCVA. ELM integrity and baseline BCVA were shown to be independent factors in the prediction of post-treatment BCVA. Comparison of post-treatment BCVA between original ELM ranks after adjusting for the baseline BCVA revealed the ELM integrity beneath the center of the fovea was important to post-treatment BCVA. ELM integrity in particular beneath the center of the fovea and baseline BCVA may be more useful than other factors in the prediction of visual function in patients with ME secondary to RVO after ranibizumab injections.

Keywords: integrity of external limiting membrane; predictors; ranibizumab; retinal vein occlusion; visual acuity.

Figure 1.

The representative figures of ranks of ELM integrity based on hyperreflective line within 1 mm diameter circle centered the fovea at baseline: Rank I, completely visible line; rank II, partially detectable line with undamaged center of fovea; rank III, partially detectable line with damaged center of fovea; rank IV, completely invisible line.

Figure 2.

The mean BCVA changes from baseline to post-treatment, showing the post-treatment logMAR BCVA was significantly better than the baseline logMAR BCVA. *P<0.05; BCVA, best-corrected visual acuity; logMAR, logarithm of the minimal angle of resolution.

Figure 3.

The mean CFT changes from baseline to post-treatment, demonstrating the post-treatment CFT was significantly thinner than the baseline CFT. *P<0.05; CFT, central foveal thickness.

Figure 4.

Comparison of post-treatment BCVA between ELM ranks after adjusting for initial BCVA, showing the post-treatment BCVA difference after adjusting for baseline BCVA between ranks II and III was significant (P=0.05). *P<0.05; BCVA, best-corrected visual acuity; ELM, external limiting membrane.