Excimer Laser Photorefractive Keratectomy (Prk) in Myopic Astigmatism

Abstract

To assess the visual and refractive results of excimer laser photorefractive keratectomy (PRK) in myopic astigmatism.

Methods

Excimer laser PRK was performed using an Aesculap Meditec MEL 60 laser in 46 myopic astigmatic eyes. Preoperative corneal astigmatism was –1.50 D. (±0.50) in 7 eyes (15.2%); –2.50 D. (±0.50) in 14 eyes (30.5%); –3.50 D. (±0.50) in 13 eyes (28.3%); –4.50 D. (±0.50) in 8 eyes (17.4%); and –5.50 D. (±0.50) in 4 eyes (8.6%). Mean preoperative cylinder was –3.50 D. (±2.50). Mean preoperative sphere was –4.50 D. (±2.25). Pre and postoperative visual acuity, refraction, keratometer readings, corneal topography, intraocular pressure, and slit lamp findings were recorded.

Results

By one year of follow-up, postoperative cylinder was between +0.50 and –0.50 D. in 31 eyes (67.4%); between –0.50 and –1.50 D. in 11 eyes (23.9%); between –1.50 and –2.50 D. in 4 eyes (8.7%). Mean post-operative cylinder was –1.21 D. (±1.70). Mean postoperative sphere was –1.09 D. (±1.25). Myopic and astigmatic improvement was achieved in each patient (100%). Topography analysis showed 69.4% were within 0.5 mm, 96.8% within 1 mm, 97.8% within 1.5 mm of centration; 55% of the patients achieved uncorrected visual acuity of 10/10 (Snellen). One patient (2.2%) lost one line of best corrected vision due to decentration and change of axis.

Conclusion

These preliminary results of myopic astigmatic excimer laser PRK procedures compare favorably in efficiency and safety with reports of PRK for myopia.