To evaluate the difference between 2.2-mm incision micro-coaxial phacoemulsification and traditional 3.0-mm coaxial phacoemulsification with respect to surgically induced astigmatism after temporally oriented clear corneal incision cataract surgery.
This prospective, randomized, intra-patient controlled study comprised 22 patients who underwent clear corneal cataract surgery in both eyes. One eye received 2.2-mm incision micro-coaxial phacoemulsification with intraocular lens (IOL) implantation and the fellow eye received traditional 3.0-mm coaxial incision phacoemulsification with IOL implantation. The 2.2-mm incisions were created with a diamond keratome after a 200-µm groove was constructed in clear cornea at the temporal limbus. The 3.0-mm incisions were created without a pre-cut groove, using a metal keratome. All cases were uncomplicated. Pre- and postoperative keratometric astigmatism at 6 weeks was measured using a hand held Nikon Retinomax K-plus 2 Autorefractor. Three methods were used to analyze the surgically induced astigmatism (SIA) data: 1) algebraic analysis of the magnitude of keratometric astigmatism induced by the surgery, 2) magnitude of SIA by vector analysis, and 3) aggregate analysis of astigmatism using vector analysis.
The mean change in the magnitude of keratometric astigmatism was 0.10±0.08 diopters (D) with the 2.2-mm micro-coaxial incisions and 0.32±0.20 D with the 3.0-mm traditional incisions (P=.0002). Using vector analysis, the mean magnitude of SIA was 0.35±0.21 D with the 2.2-mm incisions and 0.67±0.48 D (P=.006) with the 3.0-mm incisions.
Surgically induced astigmatism with 2.2-mm micro-coaxial incisions and traditional 3.0-mm clear corneal incisions with intra-patient control resulted in statistically and clinically significant reduction in surgically induced astigmatism with the smaller incision size. [J Refract Surg. 2009;25:21-24.]
From Jules Stein Eye Institute/UCLA (Masket) and Advanced Vision Care (Masket, Belani), Los Angeles, Calif; and the Department of Ophthalmology, Baylor College of Medicine, Houston, Tex (Wang).
Dr Masket is a consultant for Alcon Laboratories Inc, Ft Worth, Tex. The remaining authors have no proprietary interest in the materials presented herein.
Correspondence: Samuel Masket, MD, Advanced Vision Care, 2080 Century Park E, Ste 911, Los Angeles, CA 90067. Tel: 310.229.1220; Fax: 310.229.1222; E-mail: email@example.com
Received: August 20, 2007
Accepted: January 18, 2008
Posted online: May 15, 2008