Abstract
Purpose: :
To evaluate macular function and morphology of grade IV Age-Related Eye Disease Study (AREDS) patients over a time course of 36 months and to furthermore examine differences between patients, who remain non-neovascular and those who developed choroidal neovascularization (CNV).
Methods: :
52 eyes of 52 patients with neovascular age-related macular degeneration (AMD) in one eye (non-study eye) and non-exudative AMD in the other eye (study eye) defined as AREDS category IV were enrolled into this prospective comparative observational study. Mean follow-up was 23.7 months. Visual function was evaluated by assessing best corrected visual acuity (BCVA), fundus-controlled microperimetry (Nidek MP1) and optical coherence tomography (OCT). The results were analyzed for all patients and additionally a separate analysis of patients who developed CNV (group 1) versus patients who continued to show non-neovascular AMD (group 2).
Results: :
Mean BCVA remained stable in the overall group 2 (0.06 to 0.03 logMAR), but decreased in group 1 (0.00 to 0.13 logMAR). By microperimetry, the size of absolute scotoma, i.e. number of stimuli not recognized by the patient, did not increase significantly either in group 1 (0.08 to 0.1) or in group 2 (1.05 to 2.00). Mean retinal sensitivity decreased similarly in group 1 and group 2 (11.76 to 7.9 db and 11.99 to 9.29 db, respectively). A considerable difference was noted in the central two degrees of the tested field: group 1 patients experienced a 49.9% decrease while group 2 deteriorated only by 28.3%. Retinal sensitivity of the periphery remained relatively stable in both groups. Mean retinal thickness increased slightly in group 2 (179.90 to 196.90 µm), but markedly in group 1 (188.20 to 224.50 µm).
Conclusions: :
The mean BCVA of AREDS IV patients remained stable during the follow-up period of 36 months while mean central retinal sensitivity decreased continuously. Additional functional tests may be required to assess retinal function realistically in the follow-up of patients with high risk features for AMD.
Keywords: age-related macular degeneration • choroid: neovascularization • visual acuity