Study finds, Corneal Wave Speed and Ocular Rigidity in Norma
Now open: Certificate Course in Management of Covid-19 by Govt. Of Gujarat and PlexusMDKnow more...Now open: Certificate Course in Management of Covid-19 by Govt. Of Gujarat and PlexusMDKnow more...
Ocular biomechanics were compared between treated glaucoma patients and healthy subjects matched for age, IOP, and axial length. There was no difference in corneal wave propagation speed, but ocular rigidity was lower in glaucomatous eyes.

In this study, Researchers compared corneal wave speed (a measure of corneal elasticity) and ocular rigidity coefficient between glaucomatous and normal eyes.

20 glaucomatous eyes from 10 patients and 20 normal eyes from 13 controls, matched for age, intraocular pressure (IOP), and axial length were included. Ocular rigidity was calculated based on the difference in supine IOP by pneumatonometry with and without a 10-g weight. Corneal wave speed was determined by ultrasound surface wave elastography.

A small, 0.1 s harmonic vibration at 100 Hz was generated through the closed eyelids. Wave propagation was captured by an ultrasound transducer, and wave speed was determined from the phase change with distance. Comparisons were performed using generalized estimating equation models.

--There were no significant differences in corneal wave speed between glaucomatous and normal eyes (2.16±0.25 m/s vs. 2.07±0.16 m/s).

--However, ocular rigidity was significantly lower in glaucomatous eyes (0.0218±0.0033 microL1 vs. 0.0252±0.0050 microL1).

--Corneal wave speed was not correlated with age and IOP in either group but was correlated with ocular rigidity (R=0.48) and inversely correlated with axial length (R=-0.53) in glaucomatous eyes.

Glaucomatous eyes tends to be less stiff in the eyes than healthy eyes of a same age, IOP and axial length. The fact that corneal wave speeds fluctuate, however, indicates that the corneal tissue may not be greatly damaged and scleral changes are more important in glaucoma.