Association of Localized Retinal Sensitivities with Spectral-Domain Optical Coherence Tomography-Derived Morphologic Data in Macular Subfields in Age-Related Macular Degeneration.

Introduction: This study investigated microperimetry-derived retinal sensitivity and optical coherence tomography (OCT)-based macular morphologic data in eyes with early and intermediate age-related macular degeneration (AMD). The respective metrics were compared between macular subfields and their associations were determined. Detailed knowledge of functional associations with morphology is an asset to future therapeutic trial design.

Methods: This is a cross-sectional analysis of microperimetry and spectral-domain OCT baseline data. OCT data were segmented automatically within the HEYEX software (Heidelberg Engineering). Data were assessed for Gaussian normal distribution by the D'Agostino and Pearson tests, and appropriate comparison tests were performed for parametric and nonparametric data. The association of retinal sensitivity metrics with OCT morphologic data was tested with mixed-effects models.

Results: In total, 19 eyes of 19 participants (75 ± 6.4 years) with early and intermediate AMD were included in the analysis. Both in mesopic (p < 0.05) and in scotopic red (p < 0.001) microperimetry, retinal sensitivities differed significantly between macular subfields in ANOVA. Nasal and temporal subfields showed the highest retinal sensitivities, also compared to the central subfield. Generally, subfields within the 1 mm-2 mm diameter ring showed higher retinal sensitivities than subfields within the 2 mm-3 mm diameter ring. Superior subfields demonstrated higher retinal sensitivity than inferior subfields in mesopic microperimetry. RPE thickness was mostly negatively associated with retinal sensitivity, which was pronounced in the ETDRS inner ring inferior subfield and for mesopic retinal sensitivity (t value, p value: -3.7, <0.01). In the center position, inner retinal thickness was negatively associated with mesopic retinal sensitivity (t value, p value: -2.2, <0.05).

Conclusion: Retinal layer thicknesses and their associations with retinal sensitivity show localized differences between macular subfields in early and intermediated AMD. An analysis including more subjects is necessary to confirm these trends. This knowledge is of importance since therapeutic trial design requires detailed morphologic but also functional conception in order to detect therapeutic effects and pass regulatory hurdles.