Abstract
Purpose: :
Fluorescein angiography (FA) provides valuable information regarding the retinal circulation, competency of retinal vasculature, and qualitative assessment of disease states. The FA remains the "gold standard" for detection and evaluation of treatment response of choroidal neovascularization (CNV) due to age-related macular degeneration. However, it is limited by it subjective and qualitative nature. We propose adopting a commercially available and widely utilized software program Adobe Photoshop (Adobe Systems Inc., San Jose, California, USA) in an attempt to validate an objective and quantitative method of analyzing response of CNV to treatment with intraocular triamcinolone.
Methods: :
Representative angiogram images of Brown Norway rat retinas with well documented CNV from laser induction, treated with or without intraocular triamcinalone, were evaluated. To account for the variability between imaging parameters, Adobe Photoshop was used to quantify the pixel area of each CNV lesion within the same angiogram. The response to triamcinalone therapy was expressed as a percent value relative to untreated controls. Percent values from different images were then averaged. The results obtained were compared to published results for validation. Mean scores for the treated and untreated groups represented the mean of the total cumulative scores divided by the number of identified lesion sites.
Results: :
The mean area of leakage in untreated eyes was 654 pixels with a standard error of 119. The mean area of leakage in treated eyes was 169 pixels with a standard error of 63. The difference between treated and untreated eyes was significantly different (P < 0.05). Treatment with intracular triamcinalone resulted in a 75% decrease in leakage area compared to untreated eyes.
Conclusions: :
Adobe Photoshop is a useful tool for measuring the pixel area of vascular permeability of CNV and may provide an objective and quantitative means of evaluating response of CNV to treatment in experimental and clinical studies.
Keywords: retina • imaging/image analysis: non-clinical • choroid: neovascularization