Quantitative in vivo retinal thickness measurements in healthy subjects

Purpose: The early detection of visual threatening retinal thickness alterations is important for the purpose of offering affected patients proven treatment when indicated. Currently, the clinical methods that are available for obtaining an impression of retinal thickness are subjective and require experience and expertise. The authors present measurements of foveal thickness in healthy individuals obtained by a newly developed instrument that enables a noninvasive, noncontact, safe, and fast measurement of the retinal thickness anywhere in the posterior pole. Methods: A prototype of the retinal thickness analyzer (RTA) that operates on the principle of laser-slit biomicroscopy was used, Retinal thickness was measured in healthy emmetropic volunteers. Results: Fifty eyes were measured. The average thickness at the foveola was 178 +/- 44 mu m (+/- standard deviation; range, 100-322 mu m). Conclusion: The retinal thickness measured by the RTA in healthy subjects correspond well to previous published data (in vivo and histologic) on retinal thickness, This instrument may prove valuable in detecting retinal thickness alteration in macular diseases.