Development of Refractive Errors-What Can We Learn From Inherited Retinal Dystrophies?

PurposeIt is unknown which retinal cells are involved in the retina-to-sclera signaling cascade causing myopia. As inherited retinal dystrophies (IRD) are characterized by dysfunction of a single retinal cell type and have a high risk of refractive errors, a study investigating the affected cell type, causal gene, and refractive error in IRDs may provide insight herein.DesignCase-control study.MethodsStudy Population: Total of 302 patients with IRD from 2 ophthalmogenetic centers in the Netherlands. Reference Population: Population-based Rotterdam Study-III and Erasmus Rucphen Family Study (N = 5550). Distributions and mean spherical equivalent (SE) were calculated for main affected cell type and causal gene; and risks of myopia and hyperopia were evaluated using logistic regression.ResultsBipolar cell-related dystrophies were associated with the highest risk of SE high myopia 239.7; odds ratio (OR) mild hyperopia 263.2, both P < .0001; SE −6.86 diopters (D) (standard deviation [SD] 6.38), followed by cone-dominated dystrophies (OR high myopia 19.5, P < .0001; OR high hyperopia 10.7, P = .033; SE −3.10 D [SD 4.49]); rod dominated dystrophies (OR high myopia 10.1, P < .0001; OR high hyperopia 9.7, P = .001; SE −2.27 D [SD 4.65]), and retinal pigment epithelium (RPE)-related dystrophies (OR low myopia 2.7; P = .001; OR high hyperopia 5.8; P = .025; SE −0.10 D [SD 3.09]). Mutations in RPGR (SE −7.63 D [SD 3.31]) and CACNA1F (SE −5.33 D [SD 3.10]) coincided with the highest degree of myopia and in CABP4 (SE 4.81 D [SD 0.35]) with the highest degree of hyperopia.ConclusionsRefractive errors, in particular myopia, are common in IRD. The bipolar synapse and the inner and outer segments of the photoreceptor may serve as critical sites for myopia development.