High-resolution Imaging in Male Germ Cell-Associated Kinase (MAK)-related Retinal Degeneration

To describe the characteristics of MAK-related retinal degeneration using optical coherence tomography angiography (OCTA) and adaptive optics scanning laser ophthalmoscopy (AOSLO).

Cross-sectional study.

Six patients with rod-cone degeneration and disease-causing mutations in MAK were evaluated with visual acuity, spectral-domain OCT, confocal AOSLO, and OCTA. Foveal avascular zone (FAZ) area, vessel densities, and perfusion densities of the superficial capillary plexus (SCP) and deep capillary plexus (DCP) in the central macula in all 6 patients were compared with 5 normal subjects. Cone spacing was measured in 4 patients from AOSLO images and compared with 37 normal subjects.

Patients ranged from 25 to 81 years of age (mean, 52 years). Visual acuity varied from 20/13 to 20/40⁺², except in 1 patient with cystoid macular edema whose vision was 20/60^- and 20/70⁺¹. The SCP (P = .012) and DCP (P = .013) vessel density and perfusion density (P =.015 and .013, respectively) were significantly lower in patients compared to normal subjects in the parafoveal region 1.0-3.0 mm from the fovea, but were similar to normal subjects within 1.0 mm of the fovea. The FAZ area was not significantly different from normal (all P ≥ .24). Cone spacing was normal at almost all locations in 2 patients with early disease and increased in 2 patients with advanced disease.

Although retinal vascular densities are reduced and cone spacing is increased in advanced disease, central foveal structure is maintained until late stages of disease, which may contribute to preservation of foveal vision in eyes with MAK-related retinal degeneration.