Choroidal Vascularity Index in young Choroideremia patients

Purpose: To evaluate choroidal features in young patients affected by Choroideremia. Methods: Young CHM patients and controls were recruited at the Eye Clinic in Florence. High resolution choroidal imaging was obtained using swept source – OCT with long OCT scans (12x9 mm OCT scans). We considered the subfoveal choroidal area within 9 mm of the optic disc in the horizontal plane and the subfoveal choroidal area within a 3 mm diameter centered over the fovea. The subfoveal choroidal thickness (SCT), total choroidal area (TCA), luminal area (LA), stromal area (SA) and choroidal vascularity index (CVI) were assessed using the “ImageJ” software in both groups. Results: Eight patients (16 eyes; mean age 19.3 ± 5.2) and 7 controls (14 eyes; mean age 19.0± 5.0 years) were included in this study. BCVA was 20/20 in both eyes of 7 CHM patients and in all controls and 20/25 in both eyes in 1 CHM patient. Mean SFCT did not differ between CHM patients and controls. LA9mm, SA9mm and TCA9mm were reduced in patients compared to the control group. LA3mm, SA3mm, TCA3mm did not differ between patients and controls. CVI9mm and CVI3mm were not different between patients and controls. Conclusion: There are no differences in the CVI between young CHM patients and controls; this result suggests a simultaneous, proportional impairment of both the stromal and vascular components of the choroid in the early stages of the disease.