Macular sensitivity and fixation patterns in normal eyes and eyes with uveitis with and without macular edema

This study aims to investigate the relationship between macular sensitivity and thickness in eyes with uveitic macular edema (UME).

This study is a prospective observational case series.

The setting for this study was clinical practice. The study included 59 (28 with UME, 31 without UME) eyes of 26 patients with uveitis and 19 eyes of 10 normal subjects. The procedure followed was fundus-related perimetry and retinal thickness map with an automated fundus perimetry/tomography system. Main outcome measures included quantification of macular sensitivity, fixation pattern, and relationship between macular sensitivity and thickness.

Fixation stability revealed that 56 eyes (93.44%) had stable fixation (>75% within the central 2° of point of fixation); three eyes (6.56%) were relatively unstable (<75% of fixation points located within 2°, >75% located within 4°); and no eye had unstable fixation (<75% of fixation points located within 4°). Evaluation of fixation location revealed that 45 eyes (76.27%) had central fixation location (>50% of fixation point within 0.5 mm of foveal center); seven eyes (11.86%) had peri-central fixation location (25% << 50% within 0.5 mm); and seven eyes (11.86%) had eccentric (<25% of fixation point within 0.5 mm) fixation location. We measured macular sensitivity and corresponding thickness in 1,708 loci of 61 study eyes. Macular sensitivity increased by 0.02 dB (95% confidence interval, 0.00, 0.06) per 1 μm increase in the thickness for the thickness values ≤280 μm. Macular sensitivity decreased by 0.04 dB (95% CI, -0.08, -0.01) per 1 μm increase in the thickness for the thickness values >280 μm.

Perimetry quantification of macular sensitivity and retinal thickness, in association with other factors, may offer novel information regarding the impact of UME on retinal function.