Relationships between regional retinal sensitivities assessed by microperimetry and their corresponding retinal layer thicknesses in healthy middle‐aged subjects

Abstract

Aims/Purpose: To investigate relationships between regional differential light sensitivity (DLS) and inner and outer retinal layer (IRL and ORL) thicknesses in healthy middle‐aged adults.Methods: Measurements were made in 42 eyes of 42 healthy individuals of mean age 51.3 ± 5.4 years (range 40–59 years), spherical equivalent (SE) between ±3.50 D and good visual acuity. Mesopic fundus‐controlled perimetry was used to measure regional DLS. Spectral‐domain optical coherence tomography (SD‐OCT) was used to measure IRL (ganglion cell‐related layer) and ORL thicknesses. DLS and retinal thickness measurements were recorded for five subfields: central fovea (1 mm diameter) and the quadrants temporal, nasal, superior, and inferior of a parafoveal ring of outer diameter 3 mm and inner diameter 1 mm. Relationships between regional DLS and corresponding IRL and ORL thicknesses were assessed through univariate and multivariate analysis.Results: Mean DLS measured in the inferior parafoveal ring quadrant was significantly correlated with mean IRL thickness (rho = −0.50; p = 0.0045). This correlation was negative, meaning that a thicker IRL was related to a worse DLS. No significant correlations emerged between mean DLS and corresponding ORL or IRL thicknesses for the other subfields. Subsequent forward stepwise multiple linear regression analysis to correct for potential confounding factors revealed that IRL thickness and SE emerged as significant predictors of DLS in the inferior quadrant (R2 model = 33%; p = 0.0004).Conclusions: A thicker macular IRL, possibly indicating transient gliosis, was associated with a worse DLS in healthy middle‐aged eyes.