Corneal thickness as a risk factor of primary open angle glaucoma

Poster Details

First Author: I.Litvin RUSSIA

Co Author(s):    L. Balashevich   A. Kachanov           

Abstract Details

Purpose:

to study the correlations between the central corneal thickness (CCT) and the intraocular pressure (IOP) in patients with primary open-angle glaucoma (POAG), patients after photorefractive keratotomy (PRK), and in healthy individuals.

Setting:

Saint–Petersburg brunch IR&TC " Eye Microsurgery" named after academician S.N. Fyodorov, Saint–Petersburg, Russia

Methods:

This retrospective study included data collected from 341 subjects (606 eyes) divided into three groups: I – 191 patients (309 eyes) with POAG; II – 50 patients (97 eyes) after PRK for high myopia, and III – 100 healthy subjects (200 eyes). CCT was measured by ?-scan-pachymeter AL-3000 (Tomey, Germany). IOP was measured by Goldmann’s tonometer. Statistical comparisons were performed using one-way ANOVA test.

Results:

Group I was subdivided into subgroups based on CCT: a) ?500µm - 51 patients (87 eyes) had Mean (±St.Dev.) CCT of 487.2±13.6µm, and IOP of 16.7±1.5mmHg; b) 501-550µm - 73 patients (119 eyes) had CCT of 521.09±20.71µm, and IOP of 17.3±1.6mmHg; c) 551-600µm - 39 patients (60 eyes) had CCT of 578.63±15.41µm, and IOP of 18.3±1.7 mmHg; d) 601-650µm - 26 patients (41 eyes) had CCT of 629.2±17.8µm, and IOP of 19.1±1.2 mmHg; e) ?651µm – 2 patients (2 eyes) had CCT of 653.3±19.3µm, and IOP of 20.7±1.2mmHg. Group II prior to the surgery had CCT of 549.3±31.9µm, and IOP of 16.6±2.2mmHg; after the surgery CCT was 471.6±43.9µm and IOP was 10.9±2.2mmHg. A correlation of glaucoma course and corneal thickness was observed: when CCT was less than 500µm, incidence of advanced stages of glaucoma was much higher than in patients with greater corneal thickness (r= 0.38). In addition, each 10µm of CCT decrease was accompanied by elevation of IOP by approximately 0.7mmHg. There was no correlation between the refractive error and the CCT or IOP. Group III had CCT of 553.8± 21.1µm, and IOP of 16.5±2.1mmHg. CCT correlated with IOP (r=0.31)

Conclusions:

Patients with low CCT (<500µm) should be considered at risk for glaucoma. For this reason, patients after PRK should be followed-up closely with IOP measurements. FINANCIAL DISCLOSURE?: No