[Optical quality of the cornea following incisional correction of astigmatism].
BACKGROUND
Unilateral lamellar keratotomy (LKT) and curved dual lamellar keratotomy (BLK) were compared to evaluate the influence of incisional correction of astigmatism on the optical quality of the cornea.


METHODS
Forty-six patients with a preoperative astigmatism greater than 1.5 D were studied. LKT was performed on 30 eyes during cataract surgery and 20 eyes were treated with a BLK. Preoperatively and 4 weeks after surgery the corneal topographical data were analyzed with ray tracing in a 3-mm optical zone. The potential visual acuity (PVA) and the optical distortion (OD), which is represented by the width of the point spread in the optical center, were calculated as parameters for the optical quality.


RESULTS
The mean surgically induced astigmatism was 2.6+/-1.5 D for the LKT group and 3.5+/-1.4 D for the BLK group. The PVA decreased significantly in the LKT group from 1.2+/-0.2 to 1.0+/-0.3 (p=0.008), whereas in the BLK group the PVA remained unchanged (p=0.916). The OD increased from 6.6+/-0.9 microm to 7.9+/-2.0 microm (p=0.007) in the LKT group. In the BLK group the values were stable (p=0.843).


CONCLUSIONS
The optical quality of the cornea decreased after unilateral keratotomy in the early postoperative period. Thus, optical quality values should also be considered in incisional correction of astigmatism.
Böhm
T
T
Klinik für Augenheilkunde, Vivantes Klinikum Neukölln, Berlin. tiziana.boehm@vivantes.de
Wirbelauer
C
C
Pham
D T
DT
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001251:Astigmatism / Q000601:surgery*; D002387:Cataract Extraction; D003315:Cornea / Q000601:surgery*; D019781:Corneal Topography; D005260:Female; D006801:Humans; D008297:Male; D008432:Mathematical Computing; D008875:Middle Aged; D011183:Postoperative Complications / Q000175:diagnosis*; D011379:Prognosis; D011446:Prospective Studies; D012815:Signal Processing, Computer-Assisted; D014792:Visual Acuity