Corneal biomechanics and intraocular pressure changes after uneventful phacoemulsification surgery

Abstract

Background Biomechanics of the cornea is represented by corneal hysteresis (CH), which is defined as the viscous damping owing to viscoelastic resistance of the cornea to deformation. Aim Assessing intraocular pressure (IOP) and corneal biomechanics alterations after phacoemulsification. Patients and methods Thirty eyes were uneventfully operated on using phacoemulsification. CH, corneal resistant factor (CRF), corneal compensated intraocular pressure (IOPcc), and Goldmann correlated intraocular pressure (IOPg) values were recorded by ocular response analyzer (ORA). Central corneal thickness (CCT) was evaluated using pentacam preoperatively and postoperatively after 1 day, 1 week, and 1 month. Results Patients comprised 22 males and 8 females, with a mean age of 63.8±6.8years. Preoperative mean CCT was 532.4±39.2 µm, mean CH was 9.4±1.7 mmHg, mean CRF was 9.5±2.0 mmHg, mean IOPg was 15.4±3.9 mmHg, and mean IOPcc was 17.1±3.6 mmHg. CCT significantly increased after 1 day and significantly decreased after 1 week, and decreased again after 1 month but remained significantly higher. CH decreased significantly after 1 day and increased to the preoperative values after 1 week and 1 month. CRF significantly increased after 1 day and then decreased significantly after 1 week and remained significantly lower. Both IOPcc and IOPg insignificantly elevated after 1 day, then significantly declined after 1 week, and insignificantly increased after 1 month but was still lower than the preoperative value. CH, CRF, and CCT correlated significantly except for 1 day after surgery. Conclusion Cataract surgery causes corneal structural alterations, changing biomechanical properties and IOP initially. CCT contributes in these parameters, as there is a correlation with CH and CRF.

Keywords

• biomechanics
• cataract
• intraocular pressure
• ocular response analyzer
• phacoemulsification