Add density to the list of corneal properties linked with glaucoma, along with thickness and hysteresis. Densitometry measurements may show promise as a good diagnostic measure in POAG, new research in the Journal of Glaucoma suggests. Compared with healthy individuals, the investigators found glaucoma patients had greater corneal densities in the anterior layer and full corneal thickness, followed by the mid-stroma and the posterior layer. Based on the examined segments, differences in corneal density were detected in the central 0mm to 2mm and 2mm to 6mm rings in all layers except the posterior.
The study included 200 eyes of 75 POAG patients and 125 healthy controls. Both groups underwent corneal topography and densitometry. The researchers evaluated participants’ anterior chamber angle, depth and volume, keratometry, central corneal thickness, central anterior elevation, anterior elevation apex, maximum anterior elevation and posterior elevation apex. Densitometry measurements were made at three depths on a 12mm-diameter circle divided into four concentric rings—0mm to 2mm, 2mm to 6mm, 6mm to 10mm and 10mm to 12mm.
Investigators found almost all layers of corneal density—as well as total corneal density—were notably greater in the POAG participants. Of note: total corneal density was positively tied to age and also showed a good diagnostic capacity for glaucoma (AUC=0.617). In a multiple linear regression designed to assess the relationship with age, gender, corneal thickness and keratometry, age emerged as a significant confounder both in the controls and POAG patients.
In addition to using this measure as a diagnostic tool, these parameters may also be helpful during follow-up, given the importance of these properties in corneal transparency and their influence on IOP measurements, the researchers explained. Still, further work is needed to determine if this corneal finding is a primary or secondary alteration in patients with POAG, the study authors noted.
Molero-Senosian M, Morales-Fernandez L, Saenz-Frances F, et al. Corneal properties in primary open angle glaucoma assessed through scheimpflug corneal topography and densitometry. J Glaucoma. December 29, 2020. [Epub ahead of print].