OCT predictors discerning progression to neovascular vs atrophic age-related macular degeneration

To characterise structural optical coherence tomography (OCT) biomarkers at intermediate age-related macular degeneration(iAMD) stage able to differentiate the progression to neovascular AMD(nAMD) or to geographic atrophy (GA) in a high-risk iAMD population showing conversion at 1-year follow-up.

multicentre, retrospective, longitudinal study including patients with iAMD at baseline who developed late AMD (nAMD or GA) during the 1-year follow-up. Patients were enroled in three retinal referral institutions: (1) San Raffaele University, Milan, Italy; (2) IRCCS Bietti Foundation, Rome, Italy; (3) University of Paris Est, Creteil, France. Logistic regression model (LRM) analyses were performed to evaluate the prognostic ability of the studied biomarkers in discriminating between nAMD and GA conversion.

We included 154 eyes (154 patients, mean age 80 ± 7 years old) with iAMD at the baseline. Eighty-eight eyes(57%) progressed to nAMD, whereas 66 eyes(43%) progressed to GA. Eyes that progressed to nAMD were characterised by a higher double-layer sign(DLS) prevalence (p < 0.001), whereas eyes that progressed to GA were characterised by greater height and diameter of the greatest drusen (p < 0.001 and p = 0.001, respectively), higher presence of HRF(p = 0.008), and iRORA(p < 0.001). LRM confirmed that DLS is a significant risk factor for nAMD conversion (OR:3.626, p = 0.037), whereas height of greatest drusen (OR:0.983, p = 0.003), presence of HRF (OR:0.147, p = 0.009), and presence of iRORA (OR:0.052, p < 0.001) were more associated with GA conversion.

Structural OCT biomarkers at the iAMD stage could help clinicians to distinguish between patients who will develop nAMD in comparison to GA. Our findings can contribute to the better management of patients with iAMD.