Posters

Intraocular pressure, central corneal thickness and corneal biomechanical changes after standard coaxial phacoemulsification with 2,75mm clear corneal incisions

Poster Details

First Author: I.Gama PORTUGAL

Co Author(s):    L. Almeida   W. Rodrigues   I. Goncalves   M. Monteiro-Grillo           

Abstract Details

Purpose:

To assess the changes in corneal biomechanical properties, central corneal thickness and intraocular pressure after standard coaxial phacoemulsification as evaluated by the Ocular Response Analyser (ORA; Reichert Ophthalmic Instruments,Buffalo, New York,USA) in order to describe the influence of cataract surgery on corneal viscoelastic proprieties and intraocular pressure.

Setting:

Hospital Santa Maria – Centro Hospitalar Lisboa Norte, Lisbon, Portugal

Methods:

20 eyes of 20 patients who underwent routine cataract surgery (standard coaxial phacoemulsification with 2,75mm clear corneal main incision) were evaluated. Goldmann-correlated intraocular pressure(IOPg) corneal-compensated intraocular pressure (IOPcc), corneal hysteresis (CH) and corneal resistance factor(CRF) were measured by biomechanical waveform analysis (ORA) preoperatively, and at postoperative day 1, day 7 and day 30 after surgery. Central corneal thickness(CTT) was measured with ORA integrated hand-held pachymeter. Preoperative values were compared with postoperative values. Axial length(AL), preoperative and postoperative refraction and intraoperative time were also recorded.

Results:

CH and CRF decreased at postoperative days 1 and 7, and then increased to preoperative values (p>0,05). CCT increased at postoperative day 1 (p<0,05), but returned to preoperative values at day 30 (p>0,05). IOPg decreased at postoperative day1 (p<0,05), but returned to preoperative values at postoperative day 30 (p>0,05). IOPcc was slightly lower at postoperative days 1 and 7, but these differences weren’t statistically significant (p>0,05). CH was inversely correlated with IOPg. CRF was inversely correlated with AL.

Conclusions:

Corneal biomechanical properties are influenced by phacoemulsification. The increase in CCT after phacoemulsification was followed by a reduction in CRF and CH. Postoperative corneal edema causes changes in corneal viscoelastic properties. It is important to consider the altered corneal biomechanics when measuring intraocular pressure after cataract surgery.

Financial Disclosure:

NONE