Abstract
Purpose :
To determine age-related changes in the peripheral retinal nerve fiber layer thickness (RNFLT) using swept-source optical coherence tomography (SS-OCT).
Methods :
Forty eyes of 40 healthy subjects were studied in three age groups, group 1 (20-40 years, n: 15 eyes) group 2 (41-60 years, n: 14 eyes), and group 3 (61 years or older, n: 11 eyes). Peripapillary RNFLT values were calculated for temporal and nasal quadrants. Besides the routine wide-angle OCT imaging, additional OCT images of the nasal periphery were obtained with a contralateral gaze. Montaging the nasal peripheral and wide angle en-face OCT images yielded the large-field peripheral RNFLT image, including at least 6 mm nasal and temporal to the optic disc, and at least 3 mm superior and inferior to the optic disc (Figure 1). The 6 mm peripheral and peripapillary RNFLT values were calculated with the Deep Range Imaging algorhythm (DRI-OCT-1) of the Topcon SS-OCT. The ratio of peripheral RNFLT-to-peripapillary RNFLT was also calculated for the two quadrants. Kruskal-Wallis One Way Analysis of Variance on Ranks was used for comparison of the RNFLT values between different age groups.
Results :
We observed an age-related decrease in the peripheral-to-peripapillary RNFLT ratios (p= 0.007 and 0.027 for the nasal and temporal quadrants, respectively). The age-related decrease in nasal peripheral RNFLT (p< 0.001) was more prominent than that in the temporal peripheral RNFLT (p= 0.018).
Conclusions :
Montaged composite images with SS-OCT may provide valuable data for peripheral RNFLT. The age-related changes in peripheral RNFLT seem to appear earlier than that in peripapillary RNFLT. SS-OCT-based analysis analysis of the nasal peripheral RNFLT may provide additional information to routine wide-angle RNFLT analysis, which provides data for temporal peripheral RNFLT. Similar analysis in patients with ocular hypertension and glaucoma should determine whether age-related changes in the peripheral RNFLT may affect regional susceptibility for glaucoma or its clinical detection.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.