Corneal hysteresis measured with the Ocular Response Analyzer^® in normal and glaucomatous eyes

Abstract

ABSTRACT.Purpose: To identify differences in corneal hysteresis (CH) and central corneal thickness (CCT) between healthy and glaucomatous patients. Methods: Retrospective observational study. One hundred and thirty-three eyes of 75 healthy and 58 glaucomatous patients were included. CH was measured in each patient using Ocular Response Analyzer. CCT was determined by ultrasonic pachymetry. For each patient, one eye was randomly selected. We used a Student t-test to search for significant differences between the different groups (p<0.05). Results: In healthy and glaucomatous eyes, mean CH values were 10.46 ± 1.6 and 8.77 ± 1.4 mm Hg, respectively. Mean CCT values were 560.2 ± 36.3 and 535.3 ± 42.7 lm, respectively. CH and CCT were significantly lower in glaucomatous eyes than in normal eyes, (p<0.05). Discussion: In our series, CH was lower in glaucomatous than in normal eyes. The relationship between glaucoma, IOP, and ocular structures may not be confined to the consideration of CCT. A low CH value could be responsible for under-estimation of IOP. CH could also be a risk factor for glaucoma, independent of IOP. Further studies are needed to support these hypotheses. Conclusion: In our investigation, CCT and CH were significantly lower in glaucomatous eyes than in healthy eyes.

Combining corneal hysteresis with central corneal thickness and intraocular pressure for glaucoma risk assessment

“…1,23 Conversely, it has been suggested that low CH might be expected to increase the risk for developing glaucomatous optic neuropathy, possibly due to reduced capacity of the eyewall to dampen IOP spikes 23,24 and/or reduced ability of optic nerve structures to suitably respond to IOP fluctuations. 1,25,26 This premise is supported by several studies, which indicate that eyes with POAG exhibit lower CH compared with normal eyes [1][2][3][12][13][14][15][16] and eyes with OH. 1,12 In addition, lower CH has been linked to both glaucoma progression 17,18 and severity.…”

“…[1][2][3][12][13][14][15][16] Accordingly, identification of a specific CH value that provides good sensitivity and specificity for differentiating eyes with and without glaucoma has been elusive. Because it is a relatively dynamic variable, however, adjusting CH for the factors that influence its variability potentially may foster a more robust relationship between CH and clinical diagnosis.…”

“…[1][2][3][12][13][14][15][16][17][18][19][20][21][22] Central corneal thickness (CCT) has received the most attention in this regard, spurred by findings from the Ocular Hypertension Treatment Study (OHTS) in which CCT was the strongest independent predictor of conversion from ocular hypertension (OH) to primary open-angle glaucoma (POAG). 22 Furthermore, the OHTS investigators reported that after subjects were split into thin, intermediate, and thick CCT subgroups, subjects in the thinnest CCT subgroup were more than three times as likely to develop glaucoma compared with subjects in the thicker CCT subgroup.…”

Corneal biomechanics measured with the ocular response analyser in patients with unilateral open-angle glaucoma

“…lower CH (Abitbol et al 2010). There is also an association between low CH and the progression of glaucoma (Congdon et al 2006).…”

Descriptive Epidemiology of Intraocular Pressure and Corneal Hysteresis Among U.S. Veterans

“…[3][4][5][6] Abitbol et al in 2009 provided the ground work for establishing population values for CH and CCT. They found healthy eyes with a mean age of 61.44 years to have a mean CH of 10.46 ± 1.6 and a mean CCT of 560.2 ± 36.3.…”