Regional Age-Related Changes on Retinal Nerve Fiber Layer Thickness as Measured by Spectral Domain Optical Coherence Tomography

Abstract

 

Purpose:

 

To evaluate the relationship between age and peripapillary retinal nerve fiber layer (RNFL) thickness in normal subjects, as determined by spectral domain optical coherence tomography (SD-OCT).

 

Methods:

 

We prospectively enrolled 144 normal subjects (144 eyes), ranging from 16 to 84 years of age. After a complete ophthalmological examination, all patients underwent RNFL thickness measurement using SD-OCT (Spectral OCT/SLO, OPKO-OTI, Miami, FL). Two scans were performed per eye, each with 3 images analyzed (automatic tracking of the optic disc; diameter of 3.4 mm; resolution of 6 µm). The correlation between age and RNFL parameters (global and sectoral) was analyzed using linear regression analysis. The slope for each parameter was also calculated.

 

Results:

 

The average RNFL thickness decreased significantly with increasing age, with a slope of -0.14 µm/year (r²=0.04, p<0.01). Six of the 30-degree sectors (12 clock hours) were significantly and inversely correlated with age, with slopes ranging from -0.10 to -0.23 µm/year (r²≥0.02, p≤0.04). While most (5/6) were localized in the inferior and temporal sectors, none of the nasal sectors correlated significantly with age (p≥0.06).

 

Conclusions:

 

Our data suggest that both global and regional RNFL thickness, as assessed by SD-OCT, decrease with age. This reduction seems to be more pronounced in the infero-temporal sectors, resembling that found in glaucomatous eyes. It suggests a possible age-related pattern of regional susceptibility that should be considered when assessing eyes over time.Figure. Slopes of change for each clock hour (eyes were converted to right eye format for analysis).  

 

Keywords: nerve fiber layer • anatomy • aging: visual performance