Abstract
Purpose: :
To investigate the relationship between optical coherence tomography (OCT)-derived measurements of retinal morphology and visual acuity in patients with neovascular age-related macular degeneration (AMD) in the Avastin (Bevacizumab) for Choroidal neovascularization (ABC) Trial.
Methods: :
122 patients with newly diagnosed subfoveal choroidal neovascularization secondary to AMD, who underwent StratusOCT imaging at enrollment, were evaluated. Early Treatment Diabetic Retinopathy Study (ETDRS) visual acuity obtained by protocol refraction was recorded for each patient. Raw StratusOCT images were analyzed at the Doheny Image Reading Center using publicly available custom software entitled "OCTOR". This software allows the grader to precisely delineate, and thus quantify, any retinal compartment of interest. Thickness/volume were calculated for: neurosensory retina, SRF, SRT, and PED; and the resulting measurements were correlated with visual acuity.
Results: :
Decreased visual acuity was correlated with increased thickness of the neurosensory retina at the foveal center point (r=-0.453, P<0.0001). Decreased visual acuity was also correlated with the maximum thickness of the neurosensory retina but the strength of correlation was less than that at the foveal center (r=-0.3810 P<0.0001). An increased total volume of SRT was also correlated with decreased visual acuity (r=-0.257, P=0.004). No statistically significant association was detected between visual acuity and the total volume of SRF or PED. In addition, no statistically significant correlation was detected between visual acuity and the maximum thickness of SRF (P=0.08), SRT (P=0.26), or PED (P=0.40).
Conclusions: :
The presence of increased thickness of the neurosensory retina at the foveal center point, and to a lesser extent increased SRT volume, was associated with decreased visual acuity at baseline in the ABC Trial. Manual segmentation of OCT images allows more accurate measurement of retinal thickness, and thus facilitates the detection of a correlation with visual acuity. In addition, quantitative subanalysis of retinal compartments, may lead to the identification of parameters relevant for functional improvement and ultimate prognosis in patients newly diagnosed with neovascular AMD.
Clinical Trial: :
www.ISRCTN.org 83325075
Keywords: age-related macular degeneration • imaging/image analysis: clinical • choroid: neovascularization