Choroideremia: Effect of age on visual acuity in patients and female carriers

Abstract

In affected males with CHM, VA decreases very slowly until subjects reach 50 years of age, at which time the rate and extent of vision loss become significantly higher. Additionally, VA decreases more rapidly as individuals get older. In contradistinction to affected males, VA loss in female carriers is much milder.

High-Resolution Adaptive Optics Retinal Imaging of Cellular Structure in Choroideremia

“…Though choroideremia patients exhibit significantly reduced peripheral vision and constricted visual fields, high visual acuity can be maintained until later decades of life (Table 1). 3 Visual acuity is driven by foveal cone function, so the retention of visual acuity until the fifth decade of life suggests that at least some foveal cones remain intact and functional until late in the disease process. In the present study, the AOSLO system resolution precludes measuring foveal cone density; however, we do measure parafoveal cone density, and find that high numbers of cones remain present within the central macula.…”

“…1,2 However, many choroideremia patients can maintain significant central vision into their 40s and 50s. 3 Retinal imaging has revealed early pigmentary changes in the periphery, followed by progressive enlargement of peripheral atrophy toward the central retina, and finally atrophy of the macula in late stages of the disease. The borders of atrophic retina exhibit characteristic scalloped edges.…”

Predictors of visual acuity and genotype-phenotype correlates in a cohort of patients with Stargardt disease

“…‘Inclusion and exclusion t test’ analyses were performed as described by Coussa et al 21 in an attempt to identify the age of onset of significant visual decline. When analysed per decade (table 2), patients initially examined in the first decade of life had significantly worse BCVA than those examined in the second decade of life (p=0.04) and remained significant when compared with pooled decades 2 through 4 (p=0.05).…”

“…The patients were then subdivided based on decade of life employing ‘inclusion and exclusion t tests’ as described previously21 to elucidate age-group affects on BCVA. To further validate this method, we analysed our cohort by using the statistical approach of Rotenstreich et al 3 using the Bonferroni procedure for pairwise comparisons.…”

Promising First Steps in Gene Therapy for Choroideremia

“…Men and boys are affected with this condition because of its X-linked inheritance, but some female carriers can be mildly symptomatic (Coussa et al, 2012), presumably depending on the degree of X chromosome inactivation. In contrast to Leber's congenital amaurosis (LCA), the first retinal degeneration target of gene therapy, choroideremia progresses slowly with a peripheral to central direction of retinal degeneration.…”