IMAGING AMD

OCT can be a highly useful tool for predicting visual outcomes in patients with neovascular AMD, according to Sebastian M Waldstein MD, Medical University of Vienna, Vienna, Austria. “OCT is the most valuable tool in our hands. We know that it gives the highest resolution, is able to quantify changes in terms of progression and it certainly has the strongest predictive value,” Dr Waldstein told the 13th EURETINA Congress.

He presented the findings of a post hoc analysis of the VIEW II, EXCITE and MONT BLANC studies, which respectively involved comparison between aflibercept vs. ranibizumab, monthly vs quarterly ranibizumab injections and PDT with ranibizumab vs ranibizumab alone. In all three studies patients underwent monthly OCT examination and masked grading of retinal morphology at the Vienna Reading Centre.

Their analysis showed that OCTdetected features such as intra-retinal cysts, pigment epithelial detachments (PEDs) and vitreomacular configurations all have a bearing on the outcomes of anti-VEGF treatment and could be important factors in treatment decisions, he noted. One of their findings was that patients with higher visual acuity at baseline tended to have a gain of around 10 letters following treatment regardless of retinal morphology. However, in eyes with low visual acuity of around 40 letters at baseline, those without cysts or PED will gain nearly 20 letters. The improvements among those with intra-retinal cysts were much lower.

Patients whose intra-retinal cysts disappear during the first three months generally don’t have a recurrence during the first year of treatment, and patients maintain a steady gain of around seven letters. Eyes where cysts are present at 12 weeks of treatment tend to show persistence even with an intensive anti-VEGF regimen, a condition called degenerative cysts. In such cases the ETDRS letter score was three letters lower on average than in eyes where the cysts resolved during the first 12 weeks.

In eyes with PED but without cysts, Dr Waldstein noted that patients generally gained about two letters less than those without PED or intra-retinal cysts. However, when cysts appeared in these patients during a PRN regimen, vision began to decline towards baseline values during the second year of treatment. Meanwhile, the presence of subretinal fluid had only a very limited prognostic value, and patients with subretinal fluid in the absence of intraretinal cysts or PED had excellent visual gains during anti-VEGF therapy.

“As regards retinal morphology, intraretinal cysts are the strongest predictive factor both for baseline vision and for visual gain and patients with degenerative cysts show the worst outcomes,” Dr Waldstein said. In terms of the vitreomacular interface, he noted that patients with posterior vitreous detachment appeared to do equally well with six injections per year as with 12 injections per year. Those with vitreomacular adhesions on the other hand required monthly injections for optimum outcomes. “The ability to predict disease outcome can be useful for the patient and the ophthalmologist because it can enable to treat as much as required without over treating,” Dr Waldstein added.