Optical Coherence Tomographic Measurement of Peripapillary Retinal Nerve Fiber Layer Thickness in Normal Human Eyes

To measure peripapillary retinal nerve fiber layer (RNFL) thickness in normal human eyes by optical coherence tomography (OCT). Eighty-one eyes of 45 normal participants were studied. Each person underwent a complete ophthalmic examinations, including measurement of visual aquity and intraocular pressure and evaluation of the anterior segment, optic disc, and retinal nerve fiber layer. None of the participants had any evidence of ocular hypertension (IOP > 21 mmHg), glaucoma or other ocular diseases. Three to six peripapapillary circular scans with a diameter of 3.4 mm were performed on both eyes of participants by optical coherence tomography (model 2000, Carl-Zeiss Med Tec). Subjects ranged in age from 18 to 52 years and refractive error ranged from -5.00 to +1.75 diopters. Average peripapillary RNFL thickness 1.74 mm from the center of the disc was 137.56 ± 16.79 µm. Average RNFL thickness in the four quadrants were: superior 161.67 ± 21.17 µm, nasal 118.38 ± 21.97 µm, inferior 163.67 ± 29.93 µm, and temporal 109.23 ± 26.35 µm. There were no statistically significant correlation between RNFL thickness and age, gender or refractive error. RNFL thickness in right and left eyes had significant correlation, especially in the inferior quadrant. (r=0.67, P=0.000) RNFL thickness of both eyes of each person are nearly the same.