Change of corneal biomechanical properties caused by phacoemulsification using corneal visualization Scheimpflug technology

To explore the corneal biomechanical characteristics change in cataractous eyes before and after phacoemulsification using corneal visualization Scheimpflug technology (Corvis ST) and evaluate the influence of 3 mm clear corneal incision on corneal biomechanics.

A self-control study was performed.Thirty-six eyes of 36 patients who received phacoemulsification were enrolled in Tianjin Eye Hospital from March to May 2015.The first/second applanation time, the first/second applanation length, the first/second applanation velocity, the highest concavity time, the highest concavity radius, peak distance(PD), deformation amplitude (DA), intraocular pressure, corrected intraocular pressure and central corneal thickness(CCT) were measured in preoperation, postoperative 1 week and postoperative 1 month.This study protocal was approved by Ethic Committee of Tianjin Eye Hospital, and written informed consent was obtained from each patient prior to any medical examination.

The first/second applanation length, intraocular pressure, corrected intraocular pressure, PD, DA and CCT were significantly different among preoperation, postoperative 1 week and postoperative 1 month (F=3.42, 5.24, 4.21, 3.82, 3.91, 4.03, 3.62; all at P<0.05). Compared with the preoperative parameters, the first applanation length value was increased, and the second applanation length was reduced; the intraocular pressure and corrected intraocular pressure were elevated, and PD and DA values were increased, and the CCT was thicked in 1 week postoperative, with significant differences between the two time points (all at P<0.05). Compared with the postoperative 1 week, the first applanation length value was reduced, and the second applanation length value was increased; the intraocular pressure and corrected intraocular pressure were lowed, and PD and DA values were smaller, and the CCT was thinner in postoperative 1 month, showing significant differences between the two time points (all at P<0.05). The first applanation length, the second applanation length, the intraocular pressure, corrected intraocular pressure, PD, DA and CCT in postoperative 1 month returned to the preoperative levels(all at P>0.05).

Corneal biomechanical properties occur change in the early stage after phacoemulsification and return to normal in postoperative 1 month .