Abstract
BackgroundTo determine the preoperative factors influencing refractive astigmatism after cataract surgery for astigmatism correction by toric intraocular lens (IOL) implantation and to evaluate the prediction model using these factors.MethodsProspective, observational case series. The right eyes of forty consecutive patients with preoperative corneal astigmatism of the total cornea of 1.5 diopters (D) or more in magnitude and scheduled for implantation of a non-toric IOL during cataract surgery with a 2.4-mm temporal clear corneal incision were examined prospectively. The vertical/horizontal astigmatism component (J0) and oblique astigmatism component (J45) of refractive and corneal astigmatism were converted using power vector analysis. Multivariate regression analysis was performed with refractive astigmatism at three months postoperatively as the dependent variable, and preoperative parameters including age, sex, refractive astigmatism, corneal astigmatism, sphere, spherical equivalent, intraocular pressure, corneal thickness, anterior chamber depth, lens thickness, lens positions (tilt and decentration), axial length, and corneal higher order aberrations as independent variables. The root mean square (RMS) errors were calculated to express the regression model fit.ResultsThe regression model for the J0 component was Postoperativekern0.34em refractivekern0.2em J0=1.05times Conealkern0.2em J0-0.14 (R2 = 0.96, P < 0.001). The model for the J45 component was Postoperativekern0.34em refractivekern0.2em J45=0.68times Conealkern0.2em J45+0.19times Preoperativekern0.34em refractivekern0.2em J45-0.06 (R2 = 0.72, P < 0.001). The mean RMS errors for preoperative corneal astigmatism alone and the multivariate model were 0.58 D and 0.46 D, respectively. There was a statistically significant difference between them (P = 0.02).ConclusionsRefractive astigmatism after implantation of a toric IOL can be predicted by the regression model more accurately than by corneal astigmatism alone. However, the prediction of oblique astigmatism remains a challenge.
Highlights
To determine the preoperative factors influencing refractive astigmatism after cataract surgery for astigmatism correction by toric intraocular lens (IOL) implantation and to evaluate the prediction model using these factors
The mean vector of preoperative and postoperative refractive astigmatism, and preoperative and postoperative corneal astigmatism was 1.24 D axis 180.0°, 0.89 D axis 0.0°, 0.59 D axis 180.0°, and 0.54 D axis 180.0°, respectively. For both refractive and corneal astigmatism, the mean of the absolute values of Vertical/horizontal astigmatism component (J0) is larger than the mean of the absolute values of Oblique astigmatism component (J45), indicating less oblique astigmatism
The magnitude of corneal astigmatism was virtually unchanged between pre- and post-operatively, and refractive astigmatism was reduced, indicating that cataract surgery had eliminated lens astigmatism
Summary
To determine the preoperative factors influencing refractive astigmatism after cataract surgery for astigmatism correction by toric intraocular lens (IOL) implantation and to evaluate the prediction model using these factors. It is necessary to reconsider which parameters predict postoperative refractive astigmatism in eyes indicated for toric IOLs. Three observational studies showed that postoperative refractive and preoperative corneal astigmatism had a significant correlation in pseudophakic eyes with non-toric IOLs, and preoperative corneal astigmatism was the most significant predictor in multivariate regression analysis [3,4,5]. Three observational studies showed that postoperative refractive and preoperative corneal astigmatism had a significant correlation in pseudophakic eyes with non-toric IOLs, and preoperative corneal astigmatism was the most significant predictor in multivariate regression analysis [3,4,5] Their correlations were assessed without considering the power of corneal astigmatism. This study is the first study to assess the correlation between postoperative refractive astigmatism and preoperative parameters in pseudophakic eyes with non-toric IOLs, including the eye with an indication of toric IOL implantation
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
