Chromatic pupilloperimetry for objective diagnosis of Best vitelliform macular dystrophy

To determine the pupil response of Best vitelliform macular dystrophy (BVMD) patients for focal blue and red light stimuli presented at 76 test points in a 16.2° visual field (VF) using a chromatic pupilloperimeter.

An observational study was conducted in 16 participants: 7 BVMD patients with a heterozygous BEST1 mutation and 9 similar-aged controls. All participants were tested for best-corrected visual acuity, chromatic pupilloperimetry and Humphrey perimetry. Percentage of pupil contraction (PPC), maximal pupil contraction velocity (MCV) and latency of MCV (LMCV) were determined.

The mean PPC and MCV recorded in BVMD patients in response to red stimuli were lower by >2 standard errors (SEs) from the mean of controls in 47% and 43% of VF test points, respectively. The mean PPC and MCV recorded in the patients in response to blue stimuli were lower by >2 SEs from the mean of controls in 36% and 24% of VF test points, respectively. The patients' mean and median MCV recorded in response to red light correlated with their Humphrey mean deviation score (r=-0.714, P=0.071 and r=-0.821, P=0.023, respectively) and visual acuity (r=0.709, P=0.074 and r=0.655, P=0.111, respectively). A substantially shorter mean LMCV was recorded in BVMD patients compared to controls in 54% and 93% of VF test points in response to red and blue light, respectively. Receiver operating characteristic analysis for LMCV in response to red light identified a test point at the center of the VF with high diagnostic accuracy (area under the curve of 0.94).

Chromatic pupilloperimetry may potentially be used for objective noninvasive assessment of rod and cone cell function in different locations of the retina in BVMD patients.