Comparison of anterior segment parameters in myopia with and without primary open-angle glaucoma.

PURPOSE: To compare anterior segment parameters between myopes with and without primary open-angle glaucoma using Pentacam scheimpflug tomography. METHODS: This was a single-center retrospective cross-sectional study. Records of patients examined with a Pentacam scheimpflug tomographer (Wavelight-Allegro Oculyzer, GmbH, Erlangen, Germany) were reviewed. Variables studied were recorded from the topographic map and included anterior chamber angle, anterior chamber volume, anterior chamber depth, keratometric readings, and corneal thickness. A general linear model for age-and spherical equivalent refraction-adjusted intergroup comparisons of the anterior segment parameters was conducted. RESULTS: The study included myopes previously diagnosed with primary open-angle glaucoma (POAG) [Mild defect, n = 81; Moderate-severe defect, n = 50] and non-glaucomatous myopes (n = 247). The results revealed a smaller anterior chamber angle, shallower anterior chamber depth, and flatter cornea curvature in the mildly glaucomatous group compared to the non-glaucomatous group (p < 0.05). Smaller anterior chamber angle, shallower anterior chamber depth, and thinner cornea thickness were also observed in the moderate-severely glaucomatous group compared to the non-glaucomatous group (p < 0.05). CONCLUSION: Glaucomatous damage in myopic patients with POAG was associated with comparatively small anterior chamber angle, shallow anterior chamber depth, flat cornea curvature, and thin cornea.

The utility of measures of anterior segment parameters of a Pentacam Scheimpflug tomographer in discriminating high myopic astigmatism from keratoconus.

The study aimed to evaluate and compare anterior segment parameters between keratoconic eyes and eyes with high myopic astigmatism using Pentacam Scheimpflug tomography. This was a retrospective cross-sectional study that included sixty keratoconic eyes (thirty-two persons) and seventy-three eyes (forty-six persons) with high myopic astigmatism with mean ages 24.72 ± 11.65years and 26.60 ± 10.69years, respectively. Twenty-three parameters from the topographic map and fifteen parameters from the Belin-Ambrosió enhanced ectasia display map of the printouts of a Scheimpflug principle-based Pentacam tomographer were evaluated for their diagnostic accuracy using Receiver Operating Characteristic (ROC) curve. All parameters except cornea volume, anterior chamber volume, and anterior chamber angle indicated a significant difference between high myopic astigmatism and keratoconic eyes. The area under the receiver operating characteristic (AUROC) of eighteen Pentacam parameters was excellent (0.9-1.0) in discriminating keratoconus from high myopic astigmatism, out of which four {anterior minimum sagittal curvature (ant. Rmin), posterior minimum sagittal curvature (post. Rmin), maximum Ambrosió relational thickness (ART max) and total deviation value (D)} indicated excellent (>90%) sensitivity and specificity in addition to the excellent AUROC values. Topographic and Belin-Ambrosió enhanced ectasia display (BAD) maps of a Scheimpflug principle-based Pentacam tomographer are useful in enhancing the diagnosis of keratoconus and may also provide valuable information in effectively screening for keratoconus cases among refractive surgery candidates with high myopic astigmatism.