Abstract
Purpose :
Optical Coherence Tomography (OCT) characteristics, such as Double layer sign (DLS) and Shallow Irregular RPE elevation (SIRE) are known to correlate with the presence of non-exudative neovascular age-related macular degeneration (NE-nAMD) and might be helpful in predicting conversion to exudative nAMD (E-nAMD). To systematically evaluate such prediction, we exploited the availability of a diagnostic accuracy study of participants with E-nAMD in the first eye who were followed for 3 years to detect onset of E-nAMD in the second eye (study eye).
Methods :
Spectral Domain-OCT scans of the study eye from the Early Detection of Neovascular AMD (EDNA) study were graded for DLS and SIRE, frequencies calculated and time to conversion to E-nAMD recorded. Chi-square tests was used to compare conversion rates and Log Rank Test to compare Kaplan-Meier survival curves of conversion for DLS and SIRE. Cox-regressions was applied to calculate the hazard ratios of conversion to E-nAMD for those with DLS and SIRE.
Results :
Out of the 459 eligible cases with SD-OCT, 104 (22.7%) developed E-nAMD during FU. At baseline, DLS was present in 101 (22%) and SIRE in 51 (11.1%) cases. Conversion to E-nAMD rate was higher in eyes with DLS and SIRE compared to those without these features (DLS:40.6% vs 17.6%, P= 1.08e-06; SIRE:37.2% vs 20.8%, P=0.008). In eyes with DLS at baseline the mean time to conversion was 18.7±10.3 and those with SIRE 18.2±10.4 months. Eyes that did not convert to E-nAMD were followed for a mean of 31.1±8.3 months. Kaplan-Meier Survival curves were significantly different between eyes with DLS or SIRE and those without these features (DLS, p<0.0001, SIRE, p<0.001). There was a greater hazard of developing E-nAMD in eyes with DLS (HR: 3.0, 95% CI: 2.0-4.4, P<0.001) and SIRE (HR: 2.4, 95% CI: 1.5-4.0, P<0.001).
Conclusions :
The presence of DLS and/or SIRE at baseline increases the hazard of developing E-nAMD in the second eyes of patients who already have E-nAMD in the first eye.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.