Opposite clear corneal incisions on the steep meridian in phacoemulsification: early effects on the cornea.
OBJECTIVE
To evaluate the effect of on-axis opposite clear corneal incisions (OCCIs) in phacoemulsification on reducing preoperative corneal astigmatism and to predict the astigmatic outcome of the incisions.


METHODS
Royal Eye Infirmary, Dorset County Hospital, and Winterbourne Hospital, Dorchester, Dorset, and the Department of Ophthalmology, East Somerset Hospital, Yeovil, Somerset, United Kingdom.


METHODS
This prospective study included all patients (n = 103) who had on-axis OCCIs as a part of routine phacoemulsification with foldable intraocular lens (IOL) implantation performed by 1 surgeon during 2000. Keratometry was done 6 to 8 weeks postoperatively. The differences in the preoperative and postoperative corneal astigmatism and corneal spherical equivalent (SE) were recorded. Surgically induced astigmatism (SIA) was calculated using vector analysis.


RESULTS
The mean reduction in corneal astigmatism was 0.50 diopter (D) (P<.001). The mean SIA was 1.57 D (95% confidence interval [CI], 1.42 to 1.71). There was a weak association between the SIA and the patient's age and axis of preoperative astigmatism. The mean change in SE was +0.02 D (95% CI, -0.08 to +0.12).


CONCLUSIONS
Results indicate that on-axis OCCIs are a reliable and practical way of reducing preexisting corneal astigmatism. The change in SE was negligible and thus can be ignored during biometry.
Tadros
Athanassius
A
Royal Eye Infirmary, Dorset County Hospital, Dorchester, Dorset, United Kingdom. athanassius@btinternet.com
Habib
Maged
M
Tejwani
Deepak
D
Von Lany
Hirut
H
Thomas
Peter
P
D000368:Aged; D000369:Aged, 80 and over; D001251:Astigmatism / Q000503:physiopathology / Q000517:prevention & control*; D003315:Cornea / Q000503:physiopathology / Q000601:surgery*; D019781:Corneal Topography; D006801:Humans; D007431:Intraoperative Complications / Q000517:prevention & control; D019654:Lens Implantation, Intraocular / Q000379:methods*; D008875:Middle Aged; D019060:Minimally Invasive Surgical Procedures; D018918:Phacoemulsification / Q000379:methods*; D011446:Prospective Studies