PURPOSE: It 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.
DESIGN: Case-control study.
METHODS: Study population: 302 patients with IRD from two ophthalmogenetic centers in the Netherlands. Reference population: population-based Rotterdam Study-III and ERF Study (N=5,550). 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.
RESULTS: Bipolar cell related dystrophies were associated with the highest risk of SE high myopia 239.7; OR mild hyperopia 263.2, both P<0.0001; SE -6.86 D [SD 6.38]); followed by cone dominated dystrophies (OR high myopia 19.5, P<0.0001; OR high hyperopia 10.7, P=0.033; SE -3.10 D [SD 4.49]); rod dominated dystrophies (OR high myopia 10.1, P<0.0001; OR high hyperopia 9.7, P=0.001; SE -2.27 D [SD 4.65]); and RPE related dystrophies (OR low myopia 2.7; P=0.001; OR high hyperopia 5.8; P=0.025; 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; in CABP4 (SE 4.81 D [SD 0.35]) with the highest degree of hyperopia.
CONCLUSIONS: Refractive 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.

RD5000 CONSORTIUM
doi.org/10.1016/j.ajo.217.07.008, hdl.handle.net/1765/101496
American Journal of Ophthalmology
Department of Ophthalmology

Hendriks, M., Verhoeven, V., Buitendijk, G., Polling, J. R., Meester-Smoor, M., Hofman, A., … Klaver, C. (2017). Development of refractive errors - what can we learn from inherited retinal dystrophies?. American Journal of Ophthalmology, 2017. doi:10.1016/j.ajo.217.07.008