Abstract
Purpose:
To model incisional on-axis corneal profile pattern changes and its relationship with potential predictors and changes in astigmatic parameters in 2.2-mm corneal incision phacoemulsification.
Methods:
Sixty-seven eyes of 67 patients were included. Power vector components were obtained from keratometry (IOL Master) and Topography corneal height data were acquired with Pentacam HR, preoperatively and at 6 months postoperatively. The elevation data were used to create a second order curve fitting polynomial function describing the corneal profile in the incisional and perpendicular axis using Matlab. Postoperative and preoperative data were substracted to determine patterns of change. Multivariate regression analysis was made to study the influence of potential predictors in patterns of change. Correlation between changes in corneal profile and astigmatic parameters was also obtained. Main outcome measures were corneal power vector components and elevation data.
Results:
Significant changes occurred only in the J0 (p=.004) and M (p=.001) parameters. Total and average corneal flattening changes were obtained on-axis, which was the most frequent pattern (n= 58, 86.6%), but they were significantly larger in the incisional vs nonincisional side (p= .001). In the latter, corneal steepening was a relatively frequent pattern (n= 24 patients, 35.8%), although potential predictors were not found. Correlation of height changes with astigmatic parameters was significant but not strong.
Conclusions:
Polynomial curve fitting accurately models corneal height on-axis changes in 2.2-mm incision, and may be useful to study the biomechanical corneal response to surgery.
Keywords: 428 astigmatism •
479 cornea: clinical science •
445 cataract