Pre-op assessment should consider interactions between demographic and ocular factors

Feb 06, 2014

Corneal refractive surgery may be more successful in eyes in which the cylinder mainly originates from the anterior cornea; therefore, in candidates for refractive surgery, surgeons should carefully assess the interaction between topographic, refractive and ocular residual astigmatism (ORA) to identify those at high risk for having significant differences between subjective cylinder and topographic astigmatism.

Corneal refractive surgery may be more successful in eyes in which the cylinder mainly originates from the anterior cornea; therefore, in candidates for refractive surgery, surgeons should carefully assess the interaction between topographic, refractive and ocular residual astigmatism (ORA) to identify those at high risk for having significant differences between subjective cylinder and topographic astigmatism. These conclusions were made by the authors of a study recently published in the Journal of Cataract & Refractive Surgery.

Researchers included 2991 eyes from 2991 myopic patients scheduled for LASIK to evaluate the influence of age, sex, ocular dominance, subjective cylinder and topographic astigmatism, subjective sphere and myopic pupil size on preexisting ocular residual astigmatism. A total of 46% of eyes had an ORA of 1.00 D or more.

Using ordinary least square estimations and odds ratios, researchers determined that negative predictors of the degree of preoperative ORA included subjective sphere, male sex and dominant eye, and that increasing age and larger mesopic pupils did not indicate ORA orientation. Further, with-the-rule astigmatism meridian was more likely to occur in eyes with low ORA, and oblique and against-the-rule meridians were related to high ORA.

To access this study, click here.

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