The role of sideport incision in astigmatism change after cataract surgery.
OBJECTIVE
To study the changes in corneal astigmatism after cataract surgery when the sideport incision is performed at a predetermined location away from the tunnel incision.


METHODS
General Hospital of Piraeus "Tzaneio", Attiki, Greece.


METHODS
A total of 333 eyes with corneal astigmatism ≤1.5 diopters (D) underwent cataract surgery. A three-step superotemporal clear corneal incision for the right eye and a superonasal clear corneal incision for the left eye (3.0 mm) was made, while the sideport incision was located at <90°, 90°-110°, and >110°. Keratometric data were measured with corneal topography EyeSys Vista 2000 pre- and postoperatively at the 1st and 6th month. Surgically induced astigmatism was calculated by vector analysis. We noted all cases in which a change >0.5 D in corneal astigmatic power occurred, as well as a change >20° in axis torque, despite axis direction.


RESULTS
After multiple logistic regression analysis was conducted, cases with >110° distance between the tunnel and sideport incision had 2.22 times (P=0.021) greater likelihood for having changed >0.5 D in astigmatic power at the 1st month and 3.45 times (P=0.031) at the 6th month postoperatively, as compared with cases with a 90°-110° distance between the tunnel and sideport incision. As for the change in the astigmatic axis, cases with <90° distance had a 4.18 times greater likelihood for having a change >20° (P<0.001) (preoperative to 1st month) as compared with cases having 90°-110° of distance.


CONCLUSIONS
For surgeons that operate only from the superior position, we propose that in order to produce an incision that is as "astigmatically neutral" as possible, they should perform the sideport incision at a 90°-110° distance.
Department of Ophthalmology, Medical School, University of Ioannina, Ioannina, Greece.
Sofia
S
Theodoulidou
Department of Ophthalmology, Medical School, University of Ioannina, Ioannina, Greece.
Ioannis
I
Asproudis
Department of Ophthalmology, Medical School, University of Ioannina, Ioannina, Greece.
Christos
C
Kalogeropoulos
Ophthalmology Clinic, General Hospital of Piraeus "Tzaneio", Attiki, Greece.
Aristidis
A
Athanasiadis
Department of Ophthalmology, Medical School, University of Ioannina, Ioannina, Greece.
Miltiadis
M
Aspiotis
astigmatism; cataract surgery; sideport incision; tunnel incision