Abstract
Purpose: :
To investigate factors associated with optic nerve head (ONH) topography in newly diagnosed primary open-angle glaucoma (POAG) patients.
Methods: :
We prospectively enrolled consecutive patients with newly diagnosed POAG without glaucoma treatment [intraocular pressure (IOP) >21 mmHg]. After a complete ophthalmological examination, those with any ocular disease other than glaucoma were excluded. Data collected included age, race, gender, IOP and central corneal thickness (CCT). All patients underwent CH measurement using the Ocular Response Analyzer and confocal scanning laser ophthalmoscopy for ONH topography evaluation. The mean of three measurements was considered for analysis. Multiple regression analysis (controlling for baseline IOP and disc area) was used to investigate factors associated with the following ONH topographic parameters: cup-to-disc ratio (CDR) and mean cup depth (MCD).
Results: :
Forty-two patients (42 eyes) were included (mean age, 66.7±11.8 years; mean IOP, 27.9±8.1). The only factor significantly associated with both CDR (r=-0.41, p=0.02) and MCD (r=-0.34, p=0.03) was CH. Central corneal thickness was significantly associated with MCD (r=-0.35, p=0.02), but not with CDR (r=-0.25, p=0.10). Although marginally significantly associated with CDR (r=0.23, p=0.10), age was not associated with MCD (r=0.06, p=0.72). No significant associations were found for gender and race (p≥0.54). When comparing eyes of patients with bilateral POAG (n=20), those with higher CH had smaller CDR in 78% of the cases.
Conclusions: :
In untreated newly diagnosed patients with POAG, those with thicker corneas and mainly higher corneal hysteresis seem to have a smaller cup-to-disc ratio and shallower cup (independently of IOP values and disc area size). This association was significant for both corneal parameters only when cup depth (but not cup-to-disc ratio) was considered. Whether these observations have implications in the understanding of glaucoma pathophysiology requires further investigation.
Keywords: optic nerve • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • cornea: clinical science