Purpose-To determine the effects of age, optic disc area, ethnicity, eye, gender, and axial length on the retinal nerve fiber layer (RNFL) in the normal human eye as measured by Stratus OCT (optical coherence tomography).Design-Cross-sectional observational study.Participants-Three hundred twenty-eight normal subjects 18 to 85 years old.
Methods-PeripapillaryFast RNFL scans performed by Stratus OCT with a nominal diameter of 3.46 mm centered on the optic disc were performed on one randomly selected eye of each subject.Main Outcome Measures-Linear regression analysis of the effects of age, ethnicity, gender, eye, axial length, and optic disc area on peripapillary RNFL thickness.Results-The mean RNFL thickness for the entire population was 100.1 μm (standard deviation, 11.6). Thinner RNFL measurements were associated with older age (P<0.001); being Caucasian, versus being either Hispanic or Asian (P = 0.006); greater axial length (P<0.001); or smaller optic disc area (P = 0.010). For every decade of increased age, mean RNFL thickness measured thinner by approximately 2.0 μm (95% confidence interval [CI], 1.2-2.8). For every 1-mm-greater axial length, mean RNFL thickness measured thinner by approximately 2.2 μm (95% CI, 1.1-3.4). For every increase in square millimeter of optic disc area, mean RNFL thickness increased by approximately 3.3 μm (95% CI, 0.6-5.6). Comparisons between ethnic groups revealed that Caucasians had mean RNFL values (98.1±10.9 μm) slightly thinner than those of Hispanics (103.7±11.6 μm; P = 0.022) or Asians (105.8±9.2 μm; P = 0.043). There was no relationship between RNFL thickness and eye or gender.Correspondence to Donald L. Budenz, MD, MPH, Bascom Palmer Eye Institute, 900 NW 17th Street, Miami, FL 33136. dbudenz@med.miami.edu. Dr Schuman is currently at the Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania. Dr Schuman is a co-patent holder of the optical coherence tomography technology. Dr Patella is an employee of Carl Zeiss Meditec. Dr Quigley is a consultant for Carl Zeiss Meditec.
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Author ManuscriptOphthalmology. Author manuscript; available in PMC 2010 August 5. Conclusions-Retinal nerve fiber layer thickness, as measured by Stratus OCT, varies significantly with age, ethnicity, axial length, and optic disc area. These variables may need to be taken into account when evaluating patients for diagnosis and follow-up of glaucoma, particularly at the lower boundary of the normal range. Due to the relatively small numbers of subjects of Asian and African descent in the normative database, conclusions regarding the effect of ethnicity should be interpreted with caution.Glaucoma is an optic neuropathy associated with accelerated apoptosis of retinal ganglion cells (RGCs) that manifests as increased cupping of the optic disc and thinning of the retinal nerve fiber layer (RNFL). The diagnosis of glaucoma is currently based on the appearance of the optic disc, RNFL, and standard achromatic perimetry. 1 The optic disc is ...