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Biomechanical glaucoma factor (BGF): a new index to consider in glaucoma suspects evaluation.

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First Author: M.Martínez Sánchez SPAIN

Co Author(s):    G. Bolívar-de-Miguel   M. Teus Guezala                 

Abstract Details

Purpose:

The aim of the study is to analyze the corneal biomechanical properties in open-angle glaucoma (OAG) compared to ocular hypertension (OHT), in newly diagnosed and treatment-naïve patients.

Setting:

Glaucoma unit, ‘‘Príncipe de Asturias’’ University Hospital, at Alcalá de Henares, Madrid.

Methods:

This is a prospective, cross sectional study.26 OAG and 8 OHT naïve patients were recruited, including one eye per patient. Goldman Applanation Tonometry (GAT-IOP), Central Corneal Thickness (CCT), RNFL thickness and MD of the 24-2 Humphrey visual field were recorded. Corneal hysteresis (CH), corneal resistance factor (CRF), Goldmann correlated intraocular pressure (IOPg), cornea-compensated IOP (IOPcc) were measured by the Ocular Reponse Analyzer (ORA) in all patients. The main dynamic corneal response parameters obtained using the Corvis ST were also registered: biomechanical corrected IOP (bIOP), pachymetry, DA ratio 1mm, DA ratio 2mm, Corvis biomechanical index (CBI) and biomechanical glaucoma factor (BGF).

Results:

Mean age, sex and RNFL thickness were not significantly different between groups. The MD of the visual field was higher in OAG patients(-4.06±3.4 vs -0.66±1.02, p=0.01). Lower values of GAT-IOP and CCT were found in the group of OAG patients vs OHT(21.2±4.6 vs 27.3±4.7 mmHg and 542.2±35.5 vs 577.3±30.3 microns respectively, and these differences were significant(p=0.002 and p=0.01). No statistically significant differences were found in the ORA variables. In contrast, the Corvis ST registered higher BGF values in the OAG group(0.45±0.2 vs 0.25±0.1 p=0.02). The rest of variables measured by Corvis ST showed no statistically significant differences between both groups.

Conclusions:

The new parameter BGF obtained by the Corvis ST last software seems to differentiate quite well eyes with OHT from eyes already with OAG. Thus, it seems that this parameter may be useful in the evaluation of glaucoma suspects. To the best of our knowledge, this is the first study analyzing the Corvis DCR parameters in eyes without any antiglaucomatous treatment.

Financial Disclosure:

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