The importance of assessing corneal biomechanical properties in glaucoma patients care - a review.

Purpose: to familiarize the public with the role of corneal biomechanics in glaucoma patient management.

Methods

Ocular Response Analyzer (ORA) is the only device that measures in vivo corneal biomechanics. Recent studies regarding "corneal biomechanics and glaucoma" were reviewed and the obtained data were compared in order to present a better understanding of the corneal biomechanical properties involvement in glaucoma care.

Results

According to the studies reviewed, in primary open angle glaucoma (POAG) the mean corneal hysteresis (CH) and the corneal resistance factor (CRF) were approximately 2 mmHg lower than in normal eyes. In ocular hypertension (OH), the mean CH was about 1mmHg higher than in POAG patients and 1mmHg lower than in the control group, while the mean CRF was about 2mmHg higher than in POAG and 1mmHg higher than in the control group. Regarding the normal tension glaucoma (NTG), there were studies that showed that the mean CH and CRF were approximately 1mmHg lower than in POAG and studies that showed similar values between the POAG and NTG groups. The mean CH did not differ much between POAG and angle closure glaucoma (ACG), being lower than in normal individuals, while CRF appeared to be higher in the ACG than in normal individuals. Concerning congenital glaucoma (CG), both CH and CRF were about 2mmHg lower than in normal eyes.

Conclusions

Corneal biomechanics influenced the IOP measurement and have been proven to be of a great significance in glaucoma patients regardless of the central corneal thickness (CCT). Lower values of CH and CRF could suggest an alteration in the corneal response associated to glaucoma.