Abstract
Purpose: :
Clinical trials for neovascular AMD commonly utilize retinal thickness measurements derived from optical coherence tomography (OCT) as anatomic outcomes, but other OCT parameters, such as intensity, are generally not considered. In this study, we perform a systematic quantitative evaluation of OCT intensity parameters, and correlate them with visual acuity, in patients newly diagnosed with neovascular age-related macular degeneration (AMD).
Methods: :
Data from 122 patients enrolled in the Avastin (Bevacizumab) for Choroidal Neovascularization (ABC) Trial, were collected. Raw StratusOCT images were analyzed using custom software entitled "OCTOR", which allows assessment of optical reflectivities derived from any morphologic compartment of the retina. Intensity values of backscattered light (average and summed) were thus calculated for the neurosensory retina, subretinal fluid, pigment epithelial detachment, and subretinal tissue. Early Treatment Diabetic Retinopathy Study (ETDRS) visual acuity obtained by protocol refraction was recorded for each patient and correlated with intensity parameters derived from the foveal central subfield.
Results: :
Decreased visual acuity was associated with increased values for summed optical reflectivities of the neurosensory retina at the foveal central subfield (r=-0.4460, P<0.0001). No statistically significant correlation was detected between visual acuity and summed intensity measurements for subretinal fluid (P=0.127), pigment epithelium detachment (P=0.293), or subretinal tissue (P=0.134). A modest correlation was detected between visual acuity and the average intensity of pigment epithelium detachment at the foveal central subfield (r=0.2645, P=0.003). No statistically significant correlation was detected between visual acuity and the average intensity measurements from the foveal central subfield for the neurosensory retinal (P=0.869), subretinal fluid (P=0.106), or subretinal tissue (P=0.810).
Conclusions: :
Several OCT-derived intensity parameters were found to correlate with visual acuity. Although these findings need further replication in other studies, quantitative analysis of light reflectivity profiles from OCT images may provide additional clinically relevant information on the functional status of patients with neovascular AMD, and other disorders.
Clinical Trial: :
www.ISRCTN.org 83325075
Keywords: imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • age-related macular degeneration