Murro V, Mucciolo DP, Giorgio D, et al. - Using swept source optical coherence tomography (OCT), researchers studied the prevalence and characteristics of cystoid spaces (CS) in individuals with a confirmed genetic diagnosis of choroideremia (CHM). CHM individuals analyzed at the Regional Reference Center for Hereditary Retinal Degenerations at the Eye Clinic in Florence were retrospectively reviewed. In total, 42 eyes of 21 CHM patients [average age was 36.5 ± 20.1 (range, 13–73 years)] were involved. For all patients, the average best-corrected visual acuity was 0.63 ± 1.00 logMar (range, 0–2,80). The authors discovered that CS were present in 15 eyes of eight individuals. In retinal areas marked by retinal pigment epithelium (RPE) and outer retinal layers atrophy in the transition zone, CS appeared as microcistoyd anomalies. Cystoid spaces in choroideremia showed peculiar characteristics; they are clusters of small-sized extrafoveal degenerative cysts located primarily in the transition zone in the inner nuclear layer where the outer retinal layers and RPE are severely damaged.