Abstract
Abstract: :
Purpose:To evaluate ocular wavefront aberrations in patients with retinitis pigmentosa (RP) and posterior subcapsular (PSC) lens opacities. Methods:The optical quality of the eye was assessed by Shack–Hartmann aberrometry and by an optical system that performed combined retinal imaging and wavefront sensing. Imaging was performed in eight patients with RP (mean age, 42 ± 15 years) and ten age–similar visually normal control subjects (mean age, 42 ± 12 years). Lens optical quality in RP patients was evaluated using slit lamp biomicroscopy, and PSC opacities were graded according to a previously published scale. High–order (3rd through 6th) ocular aberrations were determined as the root mean square (RMS) of the wavefront aberration function for a 6–mm pupil diameter. The RMS for 3rd and 4th order aberrations was determined as the square root of the sum of squares of the corresponding Zernike coefficients. Combined ocular aberrations and light scatter were measured based on the modulation transfer function (MTF) derived from the optical section retinal image. Results:The mean wavefront RMS of the patients with RP (0.98 ± 0.57 microns) was significantly greater (t = –2.58, p < 0.05) than that of the control subjects (0.50 ± 0.17 microns), indicating increased high–order wavefront aberrations. There was a statistically significant difference in 3rd order (coma–like) aberrations (t = –2.50, p < 0.05) and 4th order (spherical–like) aberrations (t = –3.32, p <0.01) between the control subjects and RP patients with PSC changes. The area under the MTF curve in patients with RP was significantly less than that of control subjects (t = 3.53, p < 0.01), indicating reduced optical quality due to combined aberrations and scatter. Conclusions:The results demonstrate a disease–related increase in high–order ocular aberrations and a decrease in the optical quality of the eye due to both aberrations and light scatter in patients with RP. These optical factors can impair visual performance and degrade the resolution of retinal imaging techniques.
Keywords: imaging/image analysis: clinical • retinal degenerations: hereditary • optical properties