Abstract
Purpose: :
To describe the baseline imaging characteristics of subjects enrolled in a longitudinal, observational study to identify the morphological and/or functional features defining the earliest identifiable CNV lesion in age-related macular degeneration (AMD).
Methods: :
Subjects >50 years with neovascular AMD in one eye and intermediate or large/confluent drusen with hyperpigmentation but no CNV or geographic atrophy in the fellow eye (study eye) at high risk for progression from dry to wet AMD were eligible for the study. To characterize the earliest sequence of changes occurring at the chorioretinal interface during the development of CNV the study eye was evaluated with ETDRS visual acuity, complete ophthalmic examination, fundus photography, fluorescein and indocyanine green angiography (FA, ICG-A), ocular coherence tomography (OCT), multifocal electroretinography (mfERG), fundus autofluorescence and retinal leakage analysis at baseline and, thereafter every 6 months for a period of 2 years or until CNV presence is confirmed by FA. Available baseline demographic and imaging data are reviewed
Results: :
In 59 subjects (30 females, 29 males, mean age 77 years) neovascular AMD was diagnosed in the non-study on average 20.4 months prior to enrollment (range 1 month -11 years, median 12.7 months). Mean baseline visual acuity was 20/32 in the study eye and 20/200 in the non-study eye consistent with the finding of macular scarring/atrophy. Drusen (large/intermediate or confluent) seen primarily on fundus photography and/or FA and hyperpigmentation were the most common baseline findings in study eyes. Fundus autofluorescence demonstrated variable patterns of hypo and hyperfluorescence. No definitive signs of CNV such as hemorrhage, lipid deposits, retinal edema, pigment epithelial or neurosensory detachments were identified on any of study baseline imaging evaluations.
Conclusions: :
Approximately 42-58% of patients CNV in one eye and age related maculopathy in the fellow eye will develop bilateral CNV within 5 years. Review of the baseline imaging of study eyes in this multimodality study demonstrated clinical findings characteristic of patients at high risk for, but, the absence of clinically recognizable CNV. Completion of this study will yield further understanding of the natural history of AMD progression.
Keywords: age-related macular degeneration • choroid: neovascularization • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound)