The factors influencing peripapillary choroidal thickness in primary open-angle glaucoma

To investigate whether there is a difference between primary open-angle glaucoma (POAG) patients and control group with regard to choroidal thickness (CT) and the factors influencing CT.

Ninety eyes of 90 patients who were being followed up with POAG and 72 eyes of 72 healthy subjects matched for age and gender were included. Peripapillary retinal nerve fiber layer thickness (RNFLT), peripapillary CT, lamina cribrosa thickness (LCT), and prelaminar tissue thickness (PTT) were measured with spectral-domain optical coherence tomography (SD-OCT) enhanced depth imaging (EDI) in all patients.

According to multi-variable linear regression analysis results, the factors influencing CT were found as axial length (AL) (B = -22.78, p = 0.002), intraocular pressure (IOP) (B = -7.95, p = 0.001), age (B  = -1.77, p = 0.009), and radial pulse rate (B  = 1.42, p = 0.015). A statistically significant relationship was not detected between CT and central corneal thickness, mean deviation value of visual field, cup/disk ratio, RNFLT, LCT, PTT. CT was found significantly thinner in glaucoma group (147.5 ± 61.2 μm) compared to control group (167.1 ± 37.3 μm). However, IOP was found significantly higher (p < 0.001) and pulse rate was found significantly lower (p = 0.021) in POAG group. IOP and pulse rate were considered to have affected CT difference between the groups. In advanced and worser stage patients, there were significant positive correlations between CT and RNFLT in inferior and superior quadrants.

In addition to previous studies, IOP and pulse rate were detected to be effective on CT. Further studies are required for determining the whole factors effective on CT and better understanding CT and glaucoma relationship.