A global survey of visual symptoms in female carriers of choroideremia and X-linked retinitis pigmentosa

Purpose

To investigate self-reported visual impairment in a large cohort of female carriers of X-linked retinal diseases around the world, using the validated Michigan Retinal Degeneration Questionnaire (MRDQ).

Design

Cross-sectional global survey study

Methods

An online survey collecting demographic and MRDQ data was distributed to self-reported female carriers of X-linked retinal diseases, and healthy controls (females with no eye disease). Respondents indicated their visual symptoms relating to everyday activities in seven visual domains: central vision, colour vision, contrast sensitivity, scotopic function, photopic peripheral vision, mesopic peripheral vision, and photosensitivity. Mann-Whitney test was used to compared visual disability scores between female carriers and healthy controls.

Results

Two-hundred and thirty-seven female carriers of X-linked retinal diseases (74.3% choroideremia and 25.7% X-linked retinitis pigmentosa) and 100 age-matched healthy controls completed the questionnaire (median age: 51 vs. 47.5 years of age, respectively). Most female carriers resided in the USA (53.6%) and Australia (17.3%), whilst healthy controls were mostly from Australia (93%). Female carriers had significantly worse visual disability, compared to controls. Female carriers who were older than 50 years had significantly worse visual function impairment for all domains, except photosensitivity, when compared to carriers less than 50 years of age.

Conclusions

This study has shown that female carriers of choroideremia and X-linked RP report significantly worse visual symptoms, compared to healthy controls. Future studies are required to correlate MRDQ responses with clinical findings, to determine the degree of retinal changes required to impact female carriers’ quality of life.