Yuting Gong1, Li Jia Chen2, Chi Pui Pang1,2, Haoyu Chen1. 1. Joint Shantou International Eye Center, Shantou University & the Chinese University of Hong Kong, Shantou, China. 2. Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, China.
Abstract
PURPOSE: To investigate photoreceptor degeneration in retinitis pigmentosa (RP) by quantitatively analysing optical intensity of ellipsoid zone (EZ) on optical coherence tomography (OCT). METHODS: We conducted OCT line scans of the horizontal meridian in 24 eyes of 24 RP patients and 30 eyes of 30 healthy controls and obtained longitudinal reflectance profiles using ImageJ at every 5 pixels. Relative optical intensity was calculated from dividing the peak of EZ by the mean of the whole retina. RESULTS: The optical intensity of EZ variation followed a similar pattern in all patients. It decreased with eccentricity and then vanished, regardless whether it was normal or reduced at the fovea. The mean relative optical intensity of EZ in RP patients was 0.69 ± 0.13 to that of control subjects at the location just before it disappeared. The relative optical intensity of EZ at fovea was significantly correlated with the best-corrected visual acuity in patients (r = -0.617, p = 0.001). CONCLUSION: The optical intensity of EZ detected by OCT can serve as a biomarker for early detection of photoreceptor degeneration in RP.
PURPOSE: To investigate photoreceptor degeneration in retinitis pigmentosa (RP) by quantitatively analysing optical intensity of ellipsoid zone (EZ) on optical coherence tomography (OCT). METHODS: We conducted OCT line scans of the horizontal meridian in 24 eyes of 24 RP patients and 30 eyes of 30 healthy controls and obtained longitudinal reflectance profiles using ImageJ at every 5 pixels. Relative optical intensity was calculated from dividing the peak of EZ by the mean of the whole retina. RESULTS: The optical intensity of EZ variation followed a similar pattern in all patients. It decreased with eccentricity and then vanished, regardless whether it was normal or reduced at the fovea. The mean relative optical intensity of EZ in RP patients was 0.69 ± 0.13 to that of control subjects at the location just before it disappeared. The relative optical intensity of EZ at fovea was significantly correlated with the best-corrected visual acuity in patients (r = -0.617, p = 0.001). CONCLUSION: The optical intensity of EZ detected by OCT can serve as a biomarker for early detection of photoreceptor degeneration in RP.