A clinical case of choroideremia

Abstract

Purpose. To present an overview of a choroideremia clinical case. Material and Methods. The article presents a clinical case of a 19-year-old patient with complaints of low distance vision, narrowing of the visual field and nictalopia since childhood. The patient underwent complex ophthalmological examination including visometry, autorefractometry, tonometry, biomicro-ophthalmoscopy with Goldman lens, computer perimetry, optical biometry, optical coherence tomography with angiography function (AngioOCT), fundus photoregistration with autofluorescence, electrophysiological examination (EP). The patient was consulted by a geneticist to confirm the basic diagnosis. Results. Visual acuity: OD = 0.1 Sph -2.0 = 1.0; OS = 0.15 Sph -1.5 = 1.0. The anterior-posterior eyeball size: OD – 24.98 mm, OS – 25.0 mm. Computer perimetry revealed narrowing of visual fields up to 10 degrees in both eyes, which correlated with changes in autofluorescence. According to EP, electrical sensitivity threshold: OD 198 µA, OS 202 µA, electrical lability: OD 37 Hz, OS 35 Hz. High visual acuity with correction in patient C. is caused by the macula condition, according to the results of AngioOCT. The retinal pigment epithelium and chorioid are thin. Chorioid outside the macular area lacks the Sattler's layer. Based on the results of a consultation with a geneticist, a pathogenic variant of the nucleotide sequence was detected in the CHM gene (chrX:85213886). Conclusion. Choroideremia is a rare genetic disease with a specific clinical picture and progressive development of visual disorder. Proper and early diagnosis allows the prevention of the disease, including prenatal diagnosis, and the development of new therapies. Keywords: choroideremia, genetic choroidal diseases, optical coherence tomography, autofluorescence, electrophysiological examination