Determinants of Normal Retinal Nerve Fiber Layer Thickness Measured by Stratus OCT

Abstract

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. NIH Public Access 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 ...

Retinal nerve fiber layer thickness in patients with retinitis pigmentosa

“…By analysing the data of 137 eyes, we found that the average RNFL thickness of RP patients (104.1±21.7 mm) was similar to that of healthy Asian subjects (105.8 ± 9.2 mm), 14 although certain patients showed thinning of RNFL as reported in very recent study. 15 In addition, we could find no agreement between RNFL thickness and visual acuity or visual field, that is, the dissociation between structural and functional measures.…”

“…Some authors report the negative effect of myopia (or axial length) on RNFL thickness. 14,20 In the present study, the average refractive error of men was smaller than that of women (men: À2.0 ± 2.2D, women: À0.9 ± 2.2D, P ¼ 0.002), whereas the average age of each group was almost the same (men: 49.8 ± 14.8 years women: 50.2±13.6 years, non-significant). Refractive error, however, was not a significant predicting factor for RNFL thickness in the present multiple regression analysis, and it is hard to reconcile the large difference between genders.…”

“…Interestingly, the rate of RNFL thinning with age was 8.3 mm per decade, which was much larger than that of normal subjects, approximately 2 mm per decade. 14 The cause of this phenomenon is not only that the thinning progressed faster in RP patients, but also that the RNFL was thicker in young RP patients and thinner in elder RP patients than normal subjects. Although the mechanisms and meaning of these differences were not investigated in this study, it is possible that the pathological characteristics of Gender, an unexpected factor on RNFL thickness, showed a strong correlation with RNFL thickness in RP (P ¼ 0.001).…”

Diagnostic accuracy of nerve fibre layer, macular thickness and optic disc measurements made with the RTVue-100 optical coherence tomograph to detect glaucoma

“…As the RTVue-100 OCT has an age and disc size adjusted separate database for Caucasians, 22 which was used by us for our patients, the age-related RNFLT and GCC difference 25,26 between our healthy control and ocular hypertensive subjects and the perimetric glaucoma patients was corrected for. We have previously shown that pupil dilation had no influence on the RNFLT and GCC measurements made with the RTVue OCT. 2 Thus we did not dilate pupil for the measurements.…”

Retinal nerve fiber layer thickness in prematurity is correlated with stage of retinopathy of prematurity

“…Refractive error and age at examination are some of the well-known confounding factors in the interpretation of peripapillary RNFL thickness. [32][33][34][35][36][37][38] In addition, we performed correlation analysis between various baseline factors and peripapillary RNFL thicknesses in multiple sectors separately. As there was a difference in the pattern of RNFL distribution according to different sectors, it would be more accurate to analyze RNFL thickness in each sector separately.…”