The predictive value of OCT characteristics for the visual outcome in neovascular AMD

The intravitreal injection of an anti-VEGF compound is the current standard of care in neovascular AMD. The response to this therapy varies greatly. To date it was not possible to determine clear predictive factors in regard to therapy response, thus making it difficult when counselling patients regarding the probability for visual improvement. The aim of this study was to evaluate baseline OCT characteristics in regard to their predictive value on the outcome of visual acuity (VA) after 12 months.

A retrospective analysis of 75 eyes with neovascular AMD treated with intravitreal anti-VEGF injections at the University Hospital of Zurich with a documented follow-up of at least 12 months. Measurement and comparison of the following OCT structures were undertaken: central retinal thickness (CRT), integrity of the IS/OS junction, and presence of intra- or subretinal fluid. VA at baseline and after 12 months was evaluated. OCT findings were compared between eyes that gained ≥ 5 letters ETDRS (group 1) and eyes that did not (group 2).

75 eyes with a mean baseline VA of 57.2 ± 15 letters and a mean baseline CRT of 430 ± 226 μm were analyzed. Although baseline VA did not differ statistically significantly, eyes in group 2 had a higher VA than eyes in group 1 (60.2 ± 16.2 vs. 54.9 ± 13.6, p = 0.123). In group 1 the change of VA after 12 months was 12.6 ± 8.0 letters while it was -5.0 ± 7.8 letters in group 2. No statistically significant differences between the two groups with respect to the analyzed OCT parameters were found. None of the analyzed OCT factors had a predictive value regarding the VA outcome at month 12.

Our study was not able to find baseline OCT parameters that could predict the course of VA after 12 months. However, eyes with a thicker central retinal thickness at presentation showed a greater reduction in CRT during the analyzed period. This was associated with a more favourable course in VA. Perhaps this might be due to a less pronounced initial morphological retinal damage.