Corneal biomechanics in steroid induced ocular hypertension

This study aims to investigate the corneal biomechanical properties of steroid sensitive refractive surgery patients and to compare these with those patients that did not have steroid induced ocular hypertension after refractive surgery.

This retrospective study in a tertiary care center involved 48 eyes with steroid induced ocular hypertension (Group I) and 61 eyes of age and sex matched refractive patients who used topical steroids for the same duration as group I without developing ocular hypertension (group II). All patients had preoperative ophthalmological examination, pachymetry and postoperative corneal hysteresis (CH) and resistance factor (CRF) measurements by ocular response analyser. The preoperative CH and CRF measurements of the two groups were compared.

The mean CH was statistically lower in group I (6.89±1.62) as compared to group II (7.80±1.30) (p=0.001). The CRF was higher in group I (7.68±2.26) as compared to group II (7.66±1.72) but the difference was not statistically significant (p=0.96). The preoperative spherical refractive error (r=0.43, p=0.00) and postoperative corneal thickness (r=0.58, p=0.001) were moderately correlated with CH.

A statistically significant decrease in CH in subjects with steroid induced ocular hypertension is found. Previous studies have revealed an association of low CH with risk of glaucomatous damage of optic nerve. This may imply risk of optic disc damage in this ocular hypertension group if not recognized and treated properly. However the results should be confirmed with larger sample sizes.