Age-related changes in the thickness of the human lamina cribrosa.

ABSTRACT

OBJECTIVE: To measure the human lamina cribrosa thickness (LCT) in vitro in fully hydrated specimens and to determine whether there is any association between thickness and age or sex. METHODS: 45 fixed human optic nerves, age range 9-90 years, were dissected from the globe and frozen sectioned. The study was divided into two parts the first investigated the overall change in LCT and cribrosal beam thickness (CBT) with age, and the second divided eyes into two specific age groups (38-49 and 78-87 years) and assessed differences with respect to age and sex. RESULTS: LCT ranged from 345.4 to 555.9 microm between the samples. A positive relationship was found between LCT and age (LCT = 2.41xage+365.5, 95% confidence interval (CI) for slope 1.31 to 3.52; r(2) = 0.30, p<0.001). A regional difference in CBT was observed, with beams being thickest at the posterior cribrosa (mean 14.8 (standard deviation (SD) 2.2) microm) and thinnest at the anterior cribrosa (9.8 (SD 2.4) microm). CBT increased with increasing age. Differences related to sex were also found, with females having relatively thinner LCT than males, irrespective of age, but this was not statistically significant. CONCLUSIONS: This study shows an increase in human LCT with increasing age. This changing structural property of the lamina cribrosa may have implications for its functioning with respect to compliance and reversibility, and has particular relevance to glaucoma, where increasing age has been identified as a strong risk factor for the development of the disease.