Article
Optical quality of the cornea after incisional astigmatic correction
Search Medline for
Authors
Published: | September 22, 2004 |
---|
Outline
Text
Objective
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
42 patients with a preoperative astigmatism greater than 1,5 diopters were studied. 30 eyes received a LKT during cataract surgery and 22 eyes were treated with a BLK. Preoperatively and 4 weeks after surgery the corneal topographical data was analyzed with ray-tracing in a 3 mm optical zone. The potential visual acuity (PVA) and the optical distortion (OD) were calculated as parameters for the optical quality.
Results
The mean surgically-induced astigmatism was 2,59±1,49 D for the LKT-group and 3,46±1,41 D for the BLK-group. The PVA decreased significantly in the LKT-group from 1,22±0,25 to 0,99±0,27 (P=0,008), whereas in the BLK-group the PVA remained unchanged from 0,87±0,17 to 0,85±0,22 (P=0,916). The OD increased from 6,65±0,91 μm to 7,86±2,01 μm (P=0,007) in the LKT-group. In the BLK-group the values were stable at 8,8±1,7 μm and 8,38±2,2 μm (P=0,843).
Conclusions
Both incisional methods achieved a good correction of astigmatism. However, the optical quality of the cornea decreased after unilateral keratotomy in the early postoperative period. Thus, the optical quality values should also be considered to further improve astigmatic corneal surgery.