Abstract
Purpose :
Blue cone monochromacy (BCM) is associated with a high prevalence of myopia. However, data on the natural history of refractive error in BCM are scarce. The aim of this study is to investigate the refractive error changes in patients with BCM to better characterize its natural progression.
Methods :
A retrospective, single-center study of patients with BCM confirmed by genotypic analysis was conducted. Study variables included age, refractive error, and genotype. Refractive error is reported as spherical equivalent of refraction (SER). Patients with at least two SER evaluations measured under 25 years of age and 2 or more years apart were included in the analysis.
Results :
Six patients met the study inclusion criteria. The mean patient age ± SD in years at the first and last measurements was 7.00 ± 5.92 (range 0.42–15.00) and 15.50 ± 7.71 (range 7.00–25.00), respectively. The mean SER ± SD at the first and last measurements was -0.58 D ± 7.76 D (range 7.75 D – -13.19 D) and -5.05 D ± 9.61 D (range 3.88 D – -22.94 D), respectively, with an average change in refraction of -4.47 D (range 0.875 D– -9.75 D). Five patients had genotypes consistent with previously described OPN1LW and OPN1MW mutations associated with BCM. One patient had a novel R151T inactivating mutation; this particular mutation demonstrated the highest myopic average SER at the first and last measurements of -13.19 D and -22.94 D, respectively, and the highest average change in refraction of -9.75 D.
Conclusions :
Although BCM is commonly associated with myopia, refractive error in this population may vary, with some patients exhibiting hyperopia. However, refractive error generally trended towards increased myopia as patients aged. The R151T variant demonstrated the most severe myopic changes, suggesting that specific genetic mutations may contribute to the degree of myopic progression in BCM.
This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.