Abstract
Purpose :
The mechanisms by which myopia predisposes to glaucoma are incompletely understood. We investigated associations of optic nerve head (ONH) structural biometric measures with spherical equivalent (SE) and axial length (AL) while controlling for the effects of other biometry.
Methods :
We examined 1344 20-year-old participants of the Western Australian Pregnancy Cohort (Raine) Study. Biometric measures of the eye were collected to establish an encyclopedic eye model. Intraclass correlation coefficients were calculated for 16 biometric measures including SE, AL, Bruch membrane opening (BMO) area, and global retinal nerve fiber layer (RNFL) thickness. Multiple linear regression models were compared.
Results :
Complete set of measures were available for 915 participants. A model including AL, anterior chamber depth (ACD), height and sex explained 82.4% of the variation in SE measures (p<0.001), and had a prediction accuracy of 91.0%. The best model explaining the variation in BMO area measures comprised AL, ACD, corneal power and RNFL thickness. For every one mm increase in AL, there was a 0.08± 0.02 mm2 increase in BMO area(p<0.001). BMO area remained in the best model explaining the variation in SE in the absence of AL.
Conclusions :
We found no direct association between SE and ONH structural biometric measures. However, longer eyes seem to have larger BMO. This supports the hypothesis that damage to the lamina cribrosa is exacerbated by shearing forces due to a longer AL.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.