Astigmatic change induced by 2.8-mm corneal incisions for cataract surgery

Abstract

Purpose: To study the induced refractive change caused by different 2.8-mm corneal incision locations in phacoemulsification.

Methods: One hundred ten patients were randomly assigned to nasal or temporal incision or to superior incision, depending on preexisting astigmatism. The authors fulfilled visual acuity, refraction, keratometry, and eye scanner analysis before and after phacoemulsification. Outcome measures were induced corneal refractive change (Fourier power vector analysis), index of surface variance (ISV) change, and visual acuity at 6 months. A comparative interventional case series was used for the study design.

Results: Induced refractive change caused by different incision locations showed differences in parameter J0 (JCC at axis 0 degrees ), which was smaller after temporal than after nasal or superior incision, with marginal clinical significance and influence in uncorrected visual acuity. ISV changes did not differ between incisional groups.

Conclusions: Small differential effects of incisions by location may be useful, depending on preexisting astigmatism. Temporal incisions are recommended for negligible astigmatism, whereas nasal and superior incisions are preferable when the steep axis is located at approximately 180 degrees and 90 degrees, respectively. (ClinicalTrials.gov number, NCT00742950).