The retinal nerve fiber layer thickness in ocular hypertensive, normal, and glaucomatous eyes with optical coherence tomography

Objective: To quantitatively assess and compare the thickness of the retina l nerve fiber layer (RNFL) in ocular hypertensive eyes with normal and glau comatous eyes using the Optical Coherence Tomograph (OCT 2000, software ver sion A4X1; Humphrey Instruments, San Lean-dro, Calif). Methods: The mean RNFL thickness of ocular hypertensive (n = 28) eyes was c ompared with age-matched normal (n = 30) and glaucomatous (n = 29) eyes. Su bject eyes were classified into diagnostic groups based on intraocular pres sure, stereoscopic disc photographs, and standard automated perimetry. Thre e circular scans were obtained for each eye at a diameter of 3.4 mm around the optic disc. In each eye, average RNFL thickness measurements were obtai ned in temporal, superior, nasal, and inferior quadrants. A single index of average RNFL thickness throughout 360 degrees also was obtained. Results: Mean (95% confidence interval) RNFL was significantly thinner in o cular hypertensive eyes than in normal eyes, 72.8 mu m (66.4-78.1 mu m) and 85.8 mu m (80.2-91.7 mu m), respectively. More specifically, RNFL was sign ificantly thinner in ocular hypertensive eyes than in normal eyes in the in ferior quadrant, 84.8 mu m (75.6-94.0 mu m) vs 107.6 mu m (99.3-115.9 mu m) ; and in the nasal quadrant, 44.1 mu m (37.5-51.7 mu m) vs 61.8 mu m (53.0- 65.6 mu m). Retinal nerve fiber layer was significantly thinner in glaucoma tous eyes than in ocular hypertensive and normal eyes throughout 360 degree s and in all quadrants. Conclusion: These findings suggest that quantitative differences in RNFL th ickness exist between age-matched ocular hypertensive, normal, and glaucoma tous eyes.