Abstract
Purpose: :
To evaluate whether normal age related nerve fiber layer (RNFL) thinning occurs at equal rates around the disc.
Methods: :
Peripapillary fast RNFL scans performed by the StratusTM OCT with nominal diameter of 3.46 mm centered on the optic disc were performed on both eyes of normal subjects over a wide age range. Following selection of one study eye per participant for analysis, clock hour and quadrant specific rates of RNFL thinning with age were calculated and compared.
Results: :
The 108 study participants ranged in age from 20 to 82 years with mean (SD) 46 (15) and had a mean (SD) average RNFL thickness of 104.7 (10.8) microns. Rates of thinning per year of age ranged from -0.51 (p=0.005, r2=0.07) at clock hour 12 to +0.11 (p=.53, r2=0.00) at clock hour 6. Similarly the rate of thinning per year in the superior quadrant was -0.49 (p<0.001, r2=0.14) and in the inferior quadrant was -0.03 (p=0.77,r2=0.00). The slopes of thinning superiorly and inferiorly were highly significantly different (p=0.001).
Conclusions: :
Age related normal RNFL thinning does not occur at equal rates around the disc and is more rapid superiorly than inferiorly.
Keywords: nerve fiber layer • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • aging