Analysis of retinal nerve fiber layer and macular thickness measurements in healthy subjects using 3-dimensional optical coherence tomography [3-D OCT]

To investigate the reproducibility of peripapillary retinal nerve fiber layer [RNFL] and macular thickness measurements in healthy Egyptian subjects using 3-dimensional optical coherence tomography [3-DOCT]. Fifty eyes of 50 healthy Egyptian subjects [30 females and 20 males] attending the outpatient clinic of Mansoura Ophthalmic Center during August and September 2008 were enrolled in this cross-sectional study. A randomly chosen single eye from each healthy subject underwent thickness measurements using 3-D OCT, before and after pupillary dilatation, by 3 trained and experienced operators. Average measurements of penpapillary RNFL and macular thickness were calculated. Comparisons of thickness measurements before and after pupillary dilatation, and among the 3 operators were performed. The RNFL thickness measurements were higher in the inferior penipapillary area by RNFL scan [average 104.7 +/- 16.7 tm] and the macular thickness measurements showed a ring-shaped hump in the 3 mm perifoveal area by macular scan [average 254.6 +/- 6.7 tim]. Comparing the penipapillary RNFL and macular thickness before and after pupillary dilatation, there was no significant difference [P > 0.05] in average, superior, inferior, temporal, or nasal peripapillary areas, in total macular volume and foveal thickness, nor in 1, 3, and 6-mm perifoveal areas, whether before or after pupillary dilatation and irrespective of which operator performed the measurements. The inferior RNFL area and the 3-mm perifoveal area showed higher thickness measurements in the peripapillary region and macular region, respectively. The thickness measurements performed using 3-D OCT showed no significant differences before and after pupillary dilatation, and showed good reproducibility