Abstract
Purpose :
To ascertain whether corneal microstructure of suspects with glaucomatous optic disc appearance (GODA), assessed by statistical modeling of Optical Coherence Tomography (OCT) corneal images, is different to that of glaucoma patients and healthy individuals.
Methods :
79 subjects were recruited from patients of the Ophthalmology Clinic of the Wroclaw Medical University: 18 primary open angle glaucoma (POAG) patients, 39 GODA suspects (19 medicated and 20 non-medicated) with normal levels of intraocular pressure (IOP) and visual field, and 22 age-matched controls. Biometry was measured using IOLMaster700 (Zeiss Meditec, Germany), IOP with CorvisST (Oculus, Germany) and corneal imaging with SOCT Copernicus (Optopol, Poland). Corneal speckle was modeled by the Generalized Gamma distribution using the method described by Jesus & Iskander (Biomed Opt Exp, 2017). Kruskal-Wallis test was used to ascertain the differences in the considered parameters between the three groups of subjects. Finally, correlation was sought between the statistical parameters of the corneal OCT speckle within each group of subjects.
Results :
There were no statistically significant differences between the three groups of subjects in age, axial length, anterior chamber depth, corneal radius, lens thickness, and white-to-white corneal diameter. CCT resulted in statistically significant differences, p=0.008, showing thinner CCT in POAG patients (536.6±18.0um) than that in GODA (554.0±31.3um) and controls (569.1±31.9um). No statistically significant differences were recorded for IOP corrected CCT (p=0.547) as opposed to the uncorrected IOP (p=0.008). No statistically significant differences were found between any of the Generalized Gamma distribution parameters. The statistical parameters of the corneal OCT speckle that describe the scatterer cross-section and scatterer density showed markedly higher and statistically significant correlations for POAG and GODA groups than those for the control group (0.942 and 0.847 versus 0.336). Exclusion of medicated subjects from the GODA groups increased that correlation to the value of 0.910.
Conclusions :
The results indicate that the seemingly nominal IOP in the glaucoma suspects group is sufficiently high for stacking and reorientation of corneal collagen lamellae inducing microstructural changes of similar character to that exhibited in the glaucoma group.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.