Retinal spectral domain optical coherence tomography in early atrophic age-related macular degeneration (AMD) and a new metric for objective evaluation of the efficacy of ocular nutrition.
OBJECTIVE
A challenge in ocular preventive medicine is identification of patients with early pathological retinal damage that might benefit from nutritional intervention. The purpose of this study is to evaluate retinal thinning (RT) in early atrophic age-related macular degeneration (AMD) against visual function data from the Zeaxanthin and Visual Function (ZVF) randomized double masked placebo controlled clinical trial (FDA IND #78973).


METHODS
Retrospective, observational case series of medical center veterans with minimal visible AMD retinopathy (AREDS Report #18 simplified grading 1.4/4.0 bilateral retinopathy). Foveal and extra-foveal four quadrant SDOCT RT measurements were evaluated in n = 54 clinical and ZVF AMD patients. RT by age was determined and compared to the OptoVue SD OCT normative database. RT by quadrant in a subset of n = 29 ZVF patients was correlated with contrast sensitivity and parafoveal blue cone increment thresholds.


RESULTS
Foveal RT in AMD patients and non-AMD patients was preserved with age. Extrafoveal regions, however, showed significant slope differences between AMD patients and non-AMD patients, with the superior and nasal quadrants most vulnerable to retinal thinning (sup quad: -5.5 μm/decade thinning vs. Non-AMD: -1.1 μm/decade, P < 0.02; nasal quad: -5.0 μm/decade thinning vs. Non-AMD: -1.0 μm/decade, P < 0.04). Two measures of extrafoveal visual deterioration were correlated: A significant inverse correlation between % RT and contrast sensitivity (r = -0.33, P = 0.01, 2 Tailed Paired T) and an elevated extrafoveal increment blue cone threshold (r = +0.34, P = 0.01, 2 Tailed T). Additional SD OCT RT data for the non-AMD oldest age group (ages 82-91) is needed to fully substantiate the model.


CONCLUSIONS
A simple new SD OCT clinical metric called "% extra-foveal RT" correlates well with functional visual loss in early AMD patients having minimal visible retinopathy. This metric can be used to follow the effect of repleting ocular nutrients, such as zinc, antioxidants, carotenoids, n-3 essential fats, resveratrol and vitamin D.
Eye Clinic, James A Lovell Federal Health Care Center, North Chicago, IL 60064, USA. Stuart.Richer1@VA.Gov
Stuart
S
Richer
Jane
J
Cho
William
W
Stiles
Marc
M
Levin
James S
JS
Wrobel
Michael
M
Sinai
Carla
C
Thomas
D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000975:Antioxidants / Q000627:therapeutic use; D015350:Contrast Sensitivity / Q000502:physiology*; D019587:Dietary Supplements; D018450:Disease Progression; D005584:Fovea Centralis; D006801:Humans; D008268:Macular Degeneration / Q000150:complications / Q000188:drug therapy / Q000473:pathology* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D012160:Retina / Q000473:pathology* / Q000503:physiopathology; D017949:Retinal Cone Photoreceptor Cells; D012164:Retinal Diseases; D012189:Retrospective Studies; D012684:Sensory Thresholds / Q000502:physiology*; D041623:Tomography, Optical Coherence / Q000379:methods; D014786:Vision Disorders / Q000188:drug therapy / Q000209:etiology / Q000473:pathology* / Q000503:physiopathology; D024341:Xanthophylls / Q000627:therapeutic use; D065146:Zeaxanthins
D000975:Antioxidants; D024341:Xanthophylls; D065146:Zeaxanthins