Modifications in corneal biomechanics and intraocular pressure after deep sclerectomy.

Purpose: To compare preoperative and postoperative measurements of corneal biomechanical properties and intraocular pressure (IOP) using Goldmann applanation tonometry (GAT) and the ocular response analyzer (ORA) in eyes undergoing deep sclerectomy with collagen implant (DSCI).

Patients And Methods: Thirty eyes of 30 glaucomatous patients undergoing deep sclerectomy with collagen implant and 30 eyes of 30 normal subjects were included. Goldmann applanation IOP, central corneal thickness (CCT), and ORA measurements [corneal compensated IOP (IOPcc), Goldmann-correlated IOP (IOPg), corneal resistance factor (CRF), and corneal hysteresis (CH)] were taken the day before deep sclerectomy with collagen implant and on days 1, 8, and 30 after surgery. Preoperative CH values were correlated to the number of preoperative medications and to the CCT. Also, the ORA measurements of normal subjects were compared with the preoperative measurements of the glaucomatous patients.

Results: The 30 glaucomatous eyes showed a statistically significant difference between preoperative and day 1 postoperative GAT IOP, ORA IOPcc, IOPg, CRF, and CH measurements. No statistically significant difference was noted when comparing the GAT IOP, ORA IOPcc, IOPg, and CRF measurements between days 1, 8, and 30 after DSCI.On the contrary, CH values were statistically different when comparing days 1, 8, and 30 after DSCI. The 30 normal eyes showed no statistical difference when compared with the preoperative IOPg parameter in the 30 glaucomatous eyes; the mean CRF and the mean CH values were statistically significantly higher than the preoperative values of the glaucomatous group.

Conclusions: CH statistically increased between preoperative and postoperative day 1 DSCI. On days 8 and 30, the change in CH values was statistically significant.