Evaluation of Retinal Nerve Fiber Layer Thickness in Retinitis Pigmentosa Patients Using Spectral-Domain OCT

Purpose To measure the peripapillary retinal nerve fiber layer (RNFL) thickness using spectraldomain OCT (SD-OCT) in patients with retinitis pigmentosa. Methods Fifty eyes of 30 patients with retinitis pigmentosa underwent a complete ocular examination, including best-corrected visual acuity (BCVA) using a Snellen chart, slit-lamp biomicroscopic examination, and Goldmann applanation intraocular pressure (IOP) measurement. Dilated fundus examination was done by using both direct and indirect ophthalmoscopy. In addition, all patients underwent peripapillary RNFL thickness measurements by using an OPKO SD-OCT. Results The mean (±SD) age of the study cohort was 45.8 (16.3) years. Eighteen of the 50 eyes (36%) showed a thinning of the peripapillary RNFL in one or more quadrants and 21 of the 50 eyes (42%) showed a thickening of the peripapillary RNFL in one or more quadrants. Four eyes (8%) showed both thinning and thickening of the peripapillary RNFL thickness. The overall circumferential RNFL thickness of the 14 eyes that showed only thinning in at least one quadrant was 78.78 μm. For the 17 eyes that showed only thickening in at least one quadrant, the RNFL thickness was 119.69 μm. The values of the eyes with thinning and the eyes with thickening were significantly different from normal (t=6.31, p<0.01 for thickening; t=3.62, p<0.01 for thinning).