Abstract
Abstract: :
Purpose: The International Classification (IC) for Age Related Macular Degeneration (AMD) has been published in 1995, but there are no data available as to its usefulness in longitudinal studies. Our aim was to determine whether or not grading based on the IC for AMD allows recognition of change during the progression of the disease. Methods: 50 eyes of 26 patients with ARM/AMD participating in the London AMD phenotyping study were selected on the basis of having had at least 5 years of review documented by colour photographs. Changes over time in the characteristics of drusen (hard or soft, distinct or confluent), pigmentary changes and end-stage disease, such as geographic atrophy (GA) or neovascular AMD (CNV) were graded. The images were primary graded by an ophthalmologist trained in grading (FS). He was masked to the main purpose of the study. The images were given randomly and there was no option for comparison across time. Then images in time-sequence were graded independently for clinical changes by the senior grader and an ophthalmologist in the Reading Centre of Moorfields Eye Hospital, but without access to the original grading forms. The clinical changes were then compared to the changes in grading by individually viewing all composite images in an adjudication session. Results: The 50 eyes of 26 patients resulted in 234 gradable images. At first presentation, 34 eyes had soft drusen, 1 had geographic atrophy and 15 had neovascular changes. Of those with no end-stage disease at baseline, 9 progressed to geographic atrophy and 14 to CNV. The clinical grading was different from the detailed IC based grading in 4 cases. Of these, 2 was on the type and size of Drusen, 2 on the existence or enlargement of the area affected by end stage disease. There was 97.8% concordance in identification of change. Conclusions: Overall, the IC was sensitive enough to determine change that was evident clinically in the vast majority of cases. The grading system is adequate for use in longitudinal studies seeking change in fundus appearance.
Keywords: age-related macular degeneration • clinical (human) or epidemiologic studies: bio • imaging/image analysis: clinical