Lamina Cribrosa Position and Age

Abstract

 

Purpose

 

To assess age-dependent changes in the lamina cribrosa (LC) position within the optic nerve head in normal eyes.

 

Methods

 

Serial horizontal enhanced depth imaging optical coherence tomography (EDI OCT) B-scans of the optic nerve head were obtained from one eye of normal subjects. Interval between EDI OCT B-scans was ~30 μm. After delineating the anterior LC surface, mean and maximum LC depths (reference plane, Bruch’s membrane edges) were measured in 11 equally spaced horizontal B-scans, excluding the LC insertion area under Bruch’s membrane and the scleral rim (Fig A and B). Using the horizontal midline EDI OCT B-scan, the lateral LC displacement from the Bruch’s membrane opening was measured as an angle (θ; Fig C). Mean and maximum LC depths were compared between three age groups (20-39, 40-59, and 60-79 years).

 

Results

 

The 86 normal subjects (mean age, 44±18 years) included 44 subjects aged 20-39, 21 aged 40-59, and 21 aged 60-79 years. Both mean and maximum LC depths were similar between the three age groups in all 11 scans, before (all p>0.51; Fig D) and after (all p>0.55) controlling for the angle of lateral LC displacement (θ) and intraocular pressure. The average value of all 11 mean LC depths was 360±72 (range, 239 to 530) µm, 369±76 (range, 274 to 524) µm, and 354±72 (range, 237 to 499) µm in the 20-39, 40-59, and 60-79 years, respectively (p=0.78). The mean and maximum LC depths did not correlate with age either before (all p>0.43; Fig E) or after (all p>0.54) controlling for the angle of lateral LC displacement (θ) and intraocular pressure.

 

Conclusions

 

The central and mid-peripheral LC position within the optic nerve head does not change significantly with age under normal conditions. Changes in the LC position appear to be associated with pathologic processes.

 

 

(A) White dots = Bruch’s membrane edges; black dots = anterior laminar insertion points; maximum lamina cribrosa (LC) depth = black double arrow; mean LC depth = (area S / length D). (B) The circle indicates the LC. (C) Angle of lateral LC displacement (θ) was measured in the horizontal midline scan of the LC. Blue dot = midpoint between the 2 Bruch’s membrane edges. Red dot = midpoint between the 2 anterior laminar insertion points. (D) Mean LC depth profiles in the 3 age groups. (E) Scatter plot of age versus mean LC depth of each eye.

 

Keywords: 577 lamina cribrosa • 413 aging