Abstract
Purpose: :
Explore SD (spectral domain) OCT characteristics in early AMD using 2 observational case series clinical data sets, one with /without associated visual function data.
Methods: :
EDTRS foveal, parafoveal & perifoveal retinal thickness in 54 primarily male AMD patients (n=98 eyes) spanning 4 decades (ages 49 to 88y) using the RTVue® SD OCT MM5 (15° x 15°) retinal thickness mode. A subset of 29 patients (n=56 eyes) had associated visual function and retinal grading data available from our completed ZVF research study (FDA IND# 78,973). Four Quadrant EDTRS sector data (Sup/Nas/Inf/Temp) compared to a larger dual gender, all ethnicity normative thickness set of (n= 1095 retinas, ages 18 - 81y) supplied by OptoVue, Inc (Fremont, CA). The AUC (area under the curve) distance photopic CSF was evaluated with a Stereo Optical, Inc (Chicago, IL) Vision Function Analyzer® with best corrective lenses.
Results: :
Distinctive horizontal horseshoe-shaped parafoveal thinning occurred faster in AMD patients but significantly in the same quadrant order with the superior most vulnerable and the temporal least vulnerable (Sup Quad: -5.5u vs. -1.6u (norm), P<0.01; Nas: -5.1u vs. -1.5u, P<0.01; -Inf -3.9u vs. -1.4u P<0.02; Temp -2.5u vs. -0.8u P<0.13). The ZVF data set revealed the same accelerated overall thinning & quadrant order effect. While non - lenticular-corrected CSF declined steeply w age (r=-0.58, P<0.01), approximately 50% of the effect appears related to accelerated retinal thinning (AUC CSF vs. % Thinning, r=-0.33, P=0.01). Notably, the SD OCT thinning and CSF decline is in early AMD retinas with near normal Snellen acuity and minimal ophthalmoscopic disease (AREDS report #18 grade 1.43 (sd 0.92) / 4.0 scale).
Conclusions: :
Pincer horizontal-oriented parafoveal SD OCT retinal thinning in primary GA & drusenoid AMD mirrors the pathological process described by Sarks and Sarks 20 years ago using serial FA, white light and EM (Eye 1988; 2: 552-77). It’s a new simple metric for early objective AMD diagnosis that correlates with CSF loss, a major measure of AMD visual disability.
Keywords: age-related macular degeneration • aging: visual performance • contrast sensitivity