Patients who were less than 68 years old at baseline showed slower visual field progression than patients who were older than 68. Eyes in the younger age group showed a visual field mean deviation of -0.004 per year compared to -0.002 in older eyes.
The age-dependent difference could be a function of mechanical changes in the lamina cribrosa over time.
Dr. Ha noted that the mechanical flexibility of the lamina cribrosa declines with age. That means younger eyes with more pliant and flexible membranes may suffer more damage to axons and other structures passing through the laminal pore. Older eyes may be somewhat protected from mechanical stress and damage by having a less pliant lamina cribrosa that causes fewer structural changes in the laminar pore.
Although the relationship between increasing baseline LCCI and faster visual field progression is clear, Dr. Ha said her institution does not routinely use LCCI in clinical practice. Performing the scans needed to assess LCCI is a currently time consuming and costly procedure, she said.
"In the future, there might be a system that would allow us to use the lamina cribrosa curvature as a prognostic factor," Dr. Ha said.
Ahnul Ha, MD
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This article was adapted from Dr. Ha's presentation at the 2017 meeting of the American Academy of Ophthalmology. Dr. Ha did not indicate a proprietary interest in the subject matter.