Posters

Optic nerve head and posterior pole thickness in Asian glaucoma patients

Poster Details

First Author: J.Iyer SINGAPORE

Co Author(s):    D. Su   H. Htoon   T. Aung              

Abstract Details

Purpose:

Glaucoma causes a reduction in the retinal nerve fibre layer (RNFL) thickness measured around the optic nerve head (ONH). This study was conducted to evaluate the correlation between ONH RNFL thickness and posterior pole retinal thickness using spectral domain ocular coherence tomography (OCT) in Asian patients with and without glaucoma. In addition the role of posterior pole retinal thickness for use in a predictive model for diagnosis of glaucoma was assessed.

Setting:

Glaucoma clinics at the Singapore National Eye Centre

Methods:

This was an observational case-control study. Posterior pole and ONH RNFL thickness was measured by OCT in 94 subjects with moderate-severe glaucoma and 187 controls without glaucoma or other macular pathology. Humphrey's Visual Field (HVF) was performed in all subjects. Correlation was obtained between the posterior pole thickness, sectoral RNFL thickness and the mean deviation (MD) on HVF. Logistic regression was performed and a prediction model created based on the assessed parameters.

Results:

Posterior pole thickness had a moderate correlation with RNFL thickness in glaucoma subjects (r = 0.495) and controls (r = 0.479). HVF MD had a moderate correlation with global RNFL thickness in the glaucoma, controls and combined groups (rho = 0.529, 0.173, 0.605 respectively, p<0.001) but the correlation was weaker with posterior pole thickness (rho= 0.237, 0.191, 0.485 respectively, p<0.001). Posterior pole thickness was not found to be have any statistically significant odds ratio for glaucoma (OR = 0.9475, 0.8901 to 1.0086) for posterior pole thickness. 95.73 % of the subjects were correctly classified as having glaucoma using a prediction model containing the assessed parameters – OCT RNFL, OCT posterior pole and HVF MD – for diagnosis of glaucoma.

Conclusions:

While sectoral posterior pole retinal thickness had moderate correlation with sectoral RNFL thickness, it was found to have a weak correlation with the MD and not to be associated with significantly higher or lower odds of having glaucoma. The predictive model using parameters such as OCT RNFL (sectoral), posterior pole (inferior and superior) and MD gives an accurate classification rate for glaucoma of 95.7%. The role of the significance of posterior pole thickness measurements is however minimal in this model.

Financial Disclosure:

NONE