Impact of Corneoscleral Contact Lens Usage on Corneal Biomechanical Parameters in Keratoconic Eyes.

OBJECTIVE

To analyze the changes in corneal biomechanical parameters of keratoconic eyes with and without intracorneal ring segment (ICRS) implants after 1 year of corneoscleral contact lens (CScL) wear.

METHODS

Seventy-four eyes of 74 patients were divided into three groups: healthy subjects (29 eyes, control group), and 2 groups of subjects with keratoconic eyes (one group of 20 eyes with ICRS implants and one of 25 eyes without them), which were fitted with CScL. Corneal hysteresis (CH), corneal resistance factor (CRF), and corneal-compensated intraocular pressure (IOPcc) were evaluated before fitting CScL and after 1 year of CScL wear. In addition, endothelial cell count (ECC) and central corneal thickness (CCT) were also recorded.

RESULTS

Corneal biomechanical parameters were lower in keratoconic corneas than in healthy corneas. Keratoconic eyes with ICRS implants had lower values than eyes without them for CH (mean±SD, 8.09±1.29 vs. 8.63±1.5 mm Hg, respectively, P=0.120), CRF (6.99±1.38 vs. 8.37±1.52 mm Hg, respectively, P=0.03), and also for CCT and ECC. Data for IOPcc were similar in all groups. After 1-year wearing CScL, no statistically significant differences in corneal biomechanical parameters were registered in any of the groups (all P>0.05), although slight differences (0.13-0.27 mm Hg) were found.

CONCLUSION

The viscoelasticity properties of the cornea did not change significantly when wearing corneoscleral contact lenses for 1 year, and therefore, these lenses seem to be safe and healthy and are a reasonable alternative option for keratoconus management.