Correlation of Central Versus Peripheral Macular Structure-Function With Acuity in Age-Related Macular Degeneration

Patients with advanced age-related macular degeneration (AMD) may have preserved visual function despite significant retinal structural changes. We aimed to evaluate the relationships among retinal thickness, macular sensitivity, and visual acuity (VA) in advanced AMD.

We examined 43 eyes of 22 patients with advanced AMD (ages 66-93 years), prospectively recruited from the Canberra Hospital Ophthalmology Department. Visual function was measured on participants with low and high contrast visual acuity (LCVA and HCVA) and 10-2 Matrix visual fields. Retinal structure was determined with spectral domain optical coherence tomography (OCT), and customized software mapped the 64 OCT macular thickness regions onto the 44 regions of the 10-2 test.

Median retinal thickness at each 10-2 region was near normal. Just 7 of 88 regions from the OCT analysis that were thicker than the median had sensitivity that declined significantly with increasing thickness (r = -0.698 ± 0.082, mean ± SD), whereas 17 of 88 thinner regions showed significantly decreasing sensitivity with decreasing thickness (r = 0.723 ± 0.078). The absolute value of deviations from median optical coherence tomography thickness (aOCT) outside the central eight degrees was significantly correlated with HCVA (r = -0.34, P = 0.047). Thickness in the central eight degrees was not. Similarly, matrix sensitivities inside the central eight degrees were significantly correlated with outer aOCT (r = -0.49, P = 0.002).

Retinal thickness outside eight degrees were significantly associated with HCVA and macular sensitivity. These results suggest that outer macular thickness may be a useful prognostic indicator in AMD.

Retinal structure at the borders of the macula may be a surrogate marker of vision and retinal thickness near fixation.