Abstract
Purpose: :
The extent and time course of vision loss in Choroideremia (CHM) is still unclear.
Methods: :
Corrected VA of 120 males with CHM and 33 carrier females were collected from 21 studies published between 1981 and 2010 as well as from 15 patients examined at the Cleveland Clinic. Cross-sectional and longitudinal analyses were used to investigate the relationship between VA and age as well as progression rate of VA with age, respectively. Age grouping effects were investigated using ANOVA.
Results: :
Mean age of affected males was 36.6±17.7 years while mean logMAR VA was 0.35±0.53. There was a significant 0.0072 decrease in VA per year (p=1.22*10-4). There was a significant difference between the VA of subgroups 50 years (0.27±0.39 vs. 0.61±0.81, p=2.90*10-5). The rate of VA loss for 50 years in affected was significantly different (0.01±0.04 vs. 0.06±0.08, p=1.23*10-2). Average age of carrier females was 35.4±17.9 years with average logMAR VA of 0.30±0.61. No significant correlation was present between VA of female carriers and age (p=0.79). 51% of carrier females have a VA better than 20/20 at 35 years compared to 25% of affected males at 30 years.
Conclusions: :
In males with CHM, VA loss progresses very slowly until the 50 years of age, at which time the vision loss becomes significant. VA decreases more rapidly as the individual ages. In female carriers disease progression is not similar to that of affected males; VA loss is much milder.
Keywords: clinical (human) or epidemiologic studies: natural history • retinal degenerations: hereditary • aging: visual performance