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Abstract #9085 Published in IGR 5-2
Retinal thickness decreases with age: an OCT study
Alamouti B; Funk JBritish Journal of Ophthalmology 2003; 87: 899-901
BACKGROUND/AIM: In three-dimensional optic disc tomography, a reference plane is required to calculate optic disc rim or cup values. The position of the reference plane often depends on the retinal thickness at the temporal disc margin. Originally it was assumed that the retinal thickness at the temporal disc margin is independent of age. The aim of this study was to check this hypothesis using optical coherence tomography, and additionally to determine the reproducibility of OCT measurements in this area. METHODS: One hundred eyes of 100 healthy volunteers were included in the study. Three OCT scans were performed on each eye. The scans were aligned vertically and placed at the temporal edge of the optic disc. For each eye, the thickness of the whole retina as well as the thickness of the retinal nerve fiber layer were calculated together with their coefficients of variation. Thereafter, retinal thickness and nerve fiber layer thickness were correlated with age. RESULTS: The mean retinal thickness was 249 (SD 22) μm. The mean nerve fiber layer thickness was 109 (22) μm. The mean coefficients of variation were 3.5% (total retinal thickness) and 8.0% (nerve fiber layer thickness). Both the total retinal thickness and the nerve fiber layer thickness were significantly correlated with age (total retina: y = 269.5 - 0.53 x x; R2 = 0.133; p = 0.0002, nerve fiber layer: y = 126.8 - 0.44 x x; R2 = 0.094; p < 0.0019). CONCLUSIONS: Using OCT scans the total retinal thickness can be calculated with high reproducibility (coefficient of variation = 3.5%). The reproducibility of nerve fiber layer thickness measurements is clearly lower (coefficient of variation = 8.0%). Both the total retinal thickness and the nerve fiber layer thickness significantly decrease with age. However, this influence of the age-related decrease in RNFL/retinal thickness on the reference plane is negligible.
Dr. Bijan Alamouti, Habsburgerstrasse 4 Freiburg, 79104, Germany. alamouti@aug.ukl.uni-freiburg.de
Classification:
2.13 Retina and retinal nerve fibre layer (Part of: 2 Anatomical structures in glaucoma)
6.9.2 Optical coherence tomography (Part of: 6 Clinical examination methods > 6.9 Computerized image analysis)