Abstract
Purpose: :
To determine the effects of ethnicity, age, gender, axial length (AL), central corneal thickness (CCT), IOP, vertical Cup/Disc ratio (v-C/D) and presence of peripapillary atrophy (PPA) on the retinal nerve fiber layer (RNFL) measurements by GDx-Variable Corneal Compensator algorithm (VCC) and Enhanced Corneal Compensator algorithm (ECC) obtained in normal subjects.
Methods: :
Normal subjects were enrolled in 10 international sites and underwent comprehensive ophthalmologic examinations and 3 GDx-VCC and ECC measurements. RNFL measurements were correlated with race, age, gender, AL,IOP,CCT, v-C/D and presence of PPA by multivariate regression analysis.
Results: :
Data from 249 normal eyes (249 subjects from various races with median age of 47 (18 - 82) yrs. old) were analyzed. TSNIT avg. averaged 54.2 ± 4.7 for VCC and 52.6 ± 4.6 µm for ECC (P<0.001). Asians gave significantly thicker value for TNSIT, Superior, Inferior avg. and Temporal median by ECC and Inferior avg. by VCC (P=0.041-<0.001). Age showed small, but significant negative correlation with TNSIT and Superior avg. by VCC and ECC, Inferior avg. by ECC (Partial correlation coefficient, PC= -0.16 - -0.26, P=0.014 - <0.001) and positive correlation with Temporal median by VCC (PC=0.22, P=0.003) ; AL showed small, but significant positive correlation with TSNIT and Superior avg. by VCC, Superior avg. by ECC and Temporal median by VCC (PC= 0.14 - 0.20, P=0.020 - 0.003); v-C/D showed small, but significant negative correlation with TSNIT avg. by ECC and VCC (PC= -0.14, -0.16, P=0.029, 0.014); and PPA influenced only Temporal median by VCC (P=0.022).
Keywords: imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • optic disc • nerve fiber layer