Changes in corneal hysteresis after clear corneal cataract surgery

Area of Science:

• Ophthalmology
• Corneal Physiology
• Biomaterials Science

Background:

• Clear corneal cataract surgery is a common procedure.
• Understanding its impact on corneal biomechanics is crucial for accurate intraocular pressure (IOP) assessment.
• Corneal hysteresis (CH) and central corneal thickness (CCT) are key biomechanical parameters.

Purpose of the Study:

• To evaluate changes in corneal hysteresis (CH) after clear corneal cataract surgery.
• To assess the influence of surgery on corneal viscoelastic properties.
• To determine the effect on intraocular pressure (IOP) measurements using noncontact tonometry (NCT) and Goldmann applanation tonometry (GAT).

Main Methods:

• Retrospective, interventional, comparative study of 101 eyes undergoing cataract surgery.
• Corneal hysteresis (CH), central corneal thickness (CCT), NCT, and GAT were measured preoperatively and on postoperative day 1.
• A control group of 48 pseudophakic eyes was included for comparison.

Main Results:

• Postoperative day 1 showed a significant increase in CCT (556.8 to 580.3 µm) and a significant decrease in CH (10.35 to 9.20 mm Hg).
• NCT values increased postoperatively (17.85 to 20.10 mm Hg), while GAT values showed no significant change (14.85 to 15.24 mm Hg).
• Postoperative CCT and CH differed significantly from the control group, unlike preoperative values.

Conclusions:

• Clear corneal cataract surgery causes significant corneal edema and reduced corneal hysteresis by postoperative day 1.
• These biomechanical changes influence the accuracy of IOP measurements.
• Postoperative corneal edema alters viscoelastic properties, affecting damping capacity and tonometry readings.