New method of quantifying corneal topographic astigmatism that corresponds with manifest refractive cylinder

Abstract

Dr. Alpins and Mr. Stamatelatos have a financial interest in the ASSORT software program used to support the planning and analysis of astigmatic correction. Dr. Ong is an employee of ASSORT.

LASIK for Spherical Refractive Myopia: Effect of Topographic Astigmatism (Ocular Residual Astigmatism, ORA) on Refractive Outcome

“…[ 8 ] ORA is defined as the vectorial difference between the corneal topographic astigmatism and the refractive cylinder at the corneal plane. [ 1 , 9 , 10 ] Our results show that a low preoperative topographic astigmatism or low ORA was correlated with a low postoperative ORA and better refractive results (EI, SI, CDVA). These differences were statistically significant.…”

JRS Standard for Reporting Astigmatism Outcomes of Refractive Surgery

“…This will certainly be the case in studies that focus more closely on the analysis of astigmatism. For example, including a similar analysis based on corneal topographic or keratometric astigmatism may be required or even more complex astigmatic analysis could be included such as the new CorT parameter as described by Alpins et al 22 Other examples include the analysis of incisional surgery, in which case the SIA and flattening effect of the incisions should be calculated and displayed, 17,23 or in a toric intraocular lens analysis where a distinction should be made between the SIA of the toric implant and the SIA of the surgical penetrating ocular incision to avoid confusion.…”

Surgically Induced Astigmatism Assessment

“…This is in addition to those automated values of corneal wavefront and paraxial curvature matching and manual keratometry. 2 These findings of this CorT study can be extended to the automated keratometry based on partial coherence interferometry of the IOLMaster and Lenstar given their equivalence with the Atlas topographer.…”

“…First, this finding of equivalence in measurements of surgically induced astigmatism (SIA) is most useful given that the parameter known as corneal topographic astigmatism (CorT) 2 was demonstrated to be a more accurate measure of corneal astigmatism using simulated keratometry from the Atlas topographer as used in this study. This is in addition to those automated values of corneal wavefront and paraxial curvature matching and manual keratometry.…”