Background: The efficacy of anti-VEGF therapy in exudative AMD has been established in several large clinical trials using a fixed injection regimen as well as a SD-OCT-based PRN regimen. In these studies, after the first three injections, an increase of the mean visual acuity was observed, which could be stabilized with constant treatment for up to 24 months. However, the specific course of the visual acuity is very different between individuals. The aim of the present study was to correlate specific initial SD-OCT parameters with the course of visual acuity in order to characterize factors that may be important for the individual visual prognosis.
Patients and methods: In a prospective case study, the visual course and SD-OCT changes of 156 patients with minimum follow-up of 12 months (mean 80.1 months) were analysed. Visual acuity (LogMar) was investigated at regular intervals and correlated with specific SD-OCT parameters (foveal thickness, height of sub-retinal fluid or presence of associated PED, presence of intra-retinal cysts, length of IS/OS break, choroidal thickness).
Results: The initial increase in visual acuity could be stabilized over time. This effect was associated with a decrease in foveal retinal thickness, which also persisted over time. While sub-retinal fluid, presence of PED, and choroidal thickness showed no prognostic relevance for the change in visual acuity, the presence of more advanced central retinal thickness, of intra-retinal cysts or a longer break in the IS/OS junction were associated with a less favourable development of visual acuity.
Conclusion: In the present study, the presence of more advanced central retinal thickness, of intra-retinal cysts or a larger IS/OS break correlated significantly with a worse visual prognosis. These might be clinical signs for more extensive pre-existing intra-retinal changes. Further analysis and new diagnostic tools may prove this and may result in specific additive neuroprotective or regenerative therapeutic approaches in exudative AMD.
Keywords: Anti-VEGF therapy; Exudative AMD; Prognostic factor; SD-OCT; Visual acuity.