Abstract

P 138

The effect of age on the biomechanical properties of the cornea

Michael Haustien, Tina Oppitz, Lutz E. Pillunat, Eberhard Spörl, Andreas G. Böhm
Klinik und Poliklinik für Augenheilkunde, Universitätsklinikum Carl Gustav Carus, Dresden

Objective
To examine the effect of age on parameters of the Ocular Response Analyzer.
Methods
In a prospective clinical trial one randomly chosen eye of 106 healthy subjects was examined (F:M=58:48). The subjects were divided in 7 groups with 12 to17 patients: 10-19y, 20-29y, 30-39y, 40-49y, 50-59y, 60-69y, over 70y. IOPcc, IOPg, CH, CRF were measured by Ocular Response Analyzer (ORA). Additionally axial length, anterior chamber depth (ACD), corneal curvature were measured by IOL-Master, cornea thickness by ultrasound pachymetry, and IOP by Goldmann Applanation Tonometry. As ORA measurements are dependent on IOP and CCT CH and CRF were adjusted according to the formula:
CHcorr = CHmess - (0.2mmHg)x(18 - IOP) + (0.02mmHg)x(540-CCT);
CRFcorr = CRFmess +(0.1mmHg)x(18 - IOP) + (0.02mmHg)x(540-CCT).
Results
CHcorr was negatively correlated to age (r=-0.248; P=0.010), gender (r=-0.199; p=0.041, ACD (r=-0.220; P=0,024). CRFcorr was negatively correlated to age (r=-0.262; P=0.007), and ACD (r=-0.204; P=0.036). Females had a higher CHcorr and CRFcorr by 0.5 mmHg compared to males. CHcorr is reduced by -0.015 mmHg/year and CRFcorr by -0.019 mmHg/year. The age-dependency of the viscoelastic properties was different in smokers (N=18; ΔCHcorr: -0.039 mmHg/year, R2=0.262; ΔCRFcorr: -0.054 mmHg/year, R2=0.339) and non smokers (N=88; ΔCHcorr: -0.011 mmHg/year, R2=0.041; CRFcorr: -0.014 mmHg/year, R2=0.04) with a higher age-dependency in smokers.
Additionally IOPcc was correlated with age (r=0.277; p=0.004), axial length (r=0.207; p=0.033).
Conclusions
CH and CRF decrease with increasing age. In comparison to the standard deviation of the ORA measurements of about 1 mmHg the influence of age is clinically negligible. However, it reflects the reduced biomechanical damping capability of the cornea with age.

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