Objective: To measure the thickness of retinal neurosensory layer, retinal pigment epithelium (RPE) and choriocapillaris in normal subjects by optical coherence tomography (OCT).
Methods: Sixty normal subjects (120 eyes) were examined by OCT with 4 mm scanning length horizontally and vertically through foveola. The mean thickness of retinal neurosensory layer, RPE and choriocapillaris thickness in foveola, 175 microns and 750 microns to foveola, were calculated and compared.
Results: The mean thickness of retinal neurosensory layer is 146.34 +/- 8.58 microns in foveola; 155.58 +/- 10.20 microns in 175 microns to foveola and 252.98 +/- 14.07 microns in 750 microns to foveola. The mean thickness of RPE and choriocapillaris is 106.26 +/- 10.58 microns in foveola; 104.98 +/- 7.24 microns in 175 microns to foveola and 106.84 +/- 9.95 microns in 750 microns to foveola. The results show that there are no significant in mean thickness of retinal neurosensory layer in 175 microns to foveola in statistics, but there are differences in 750 microns to foveola between nasal and temporal or superior, inferior and nasal, temporal. The differences in mean RPE and choriocapillaris thickness of all sites are not significant. Correlative analysis showed that there is no correlation between retinal neurosensory layer, RPE and choriocapillaris thickness and age.
Conclusion: OCT can accurately measure the thickness of retina in normal eyes and provide a subjective and Quantitative method to diagnose macular diseases.