Purpose:
Patients with neovascular age-related macular degeneration (nvAMD) in one eye are at high risk of developing neovascularization in their fellow eye. The AREDS simple scale based on the presence of drusen and pigmentary irregularities is predictive of development of neovascularization over a 5 year period. However with the development of high resolution tomography we sought to identify markers for the development of neovascularization in fellow eyes of persons with nvAMD in the short to medium term.
Methods:
Thirty patients (11 men and 19 women; mean age 75.23 ± 6.40 years) with unilateral nvAMD who were attending at monthly intervals for treatment with anti VEGF agents were included in this retrospective longitudinal study. Retinal and choroidal morphological features were assessed from OCT scans (Spectralis HRA, OCT; Heidelberg Engineering, Heidelberg, Germany) for the following: diameter and depth of the foveal depression, drusen type including autofluorescence characteristics, height and width of the largest druse, continuity of the retinal pigment epithelium (RPE), presence of hyper-reflective dots and choroidal thickness. Data were entered into a spreadsheet along with age, gender, hypertension, hyperlipidaemia, smoking status, best corrected visual acuity (BCVA), angiographic type of the CNV in the fellow eye. As patients were followed up for varying periods of time, adjustment was made for this. COX-regression models were used to identify the features that were associated with the development of neovascularisation.
Results:
Of the 30 patients included in the study 14 developed neovascularisation and 16 did not. The mean baseline BCVA in progressors was 75 letters compared to 82 letters in non progressors. Mean drusen height was 122µm and width 511µm in those who progressed, whereas in those who did not it was 70µm and 271µm respectively. The univariate COX-regression analysis showed that drusen height (p=0.006) and drusen width (p=0.027) were the strongest predictors for progression to nvAMD. The presence of hyper reflective spots, discontinuity in the RPE and BCVA at baseline also reached statistical significance. Foveal width and depth and choroidal thickness excluded by the model.
Conclusions:
The present study shows that drusen characteristics were the strongest predictors of nvAMD in fellow eyes of persons with exudative disease in one eye.
Keywords: age-related macular degeneration • choroid: neovascularization • clinical (human) or epidemiologic studies: systems/equipment/techniques