Purpose: To examine the topographic correlation between retinal morphology and retinal sensitivity by mesopic and scotopic fundus-controlled perimetry (FCP) in eyes with intermediate AMD.
Methods: Thirty-five eyes from 32 patients (mean age 70.9 years) and 29 age-matched controls prospectively underwent spectral-domain optical coherence tomography (SD-OCT) imaging. Mesopic (Goldman III, 200 ms, 4-2 strategy) and scotopic (Goldman V, 200 ms, 4-2 strategy) FCP with a 56-stimulus point grid was performed in AMD patients with the MP-1S. Thickness values of different retinal layers were measured at each stimulus point and compared, topographically corresponding to values in controls of similar age for pointwise structural-functional analysis.
Results: The overall mean sensitivity in patients was 16.9 ± 3.0 dB for mesopic and 14.0 ± 3.7 dB for scotopic testing. Within the central 4° of the macula, reduced mesopic and scotopic sensitivity values were found (P < 0.0001). These findings correlated to central increasing retinal pigment epithelium-drusen complex (RPEDC) thickness and central decreasing outer nuclear layer (ONL) and photoreceptor (PR)-segments thickness (P < 0.0001, respectively). Structure-function correlations revealed that a reduction of mesopic and scotopic sensitivity was associated with increasing thickness of the total retina and the RPEDC and a decrease of the ONL and the PR-segments (P < 0.001, respectively).
Conclusions: Accumulation of sub-RPE material in patients with intermediate AMD is spatially associated to quantifiable structural alterations in various retinal layers and to corresponding retinal dysfunction. The topographic analysis of retinal thickness and retinal sensitivity will be helpful for a better understanding of the disease process and for the evaluation of new interventional approaches.