Abstract
Purpose
To compare the topographic features of eyes treated with photorefractive keratectomy (PRK) for myopia using two different excimer lasers.
Methods
A total of 65 eyes in 39 patients treated with PRK (6.0-mm optical zone) using Technolas 217C and VISX S4 excimer lasers were evaluated retrospectively to determine the size of the topographic ablation zone.
Results
The zones ablated using the VISX S4 had shorter diameters in both axes (−0.89±0.73, −1.59±0.49 mm; both P=0.00), whereas those ablated using the Technolas 217C had a longer diameter in the major axis (0.96±0.63 mm; P=0.00) and a shorter diameter in the minor axis (−0.39±0.59 mm; P=0.00). The theoretical ablated zone was a circle with a diameter of 6.0 mm. The Technolas 217C group tended to have oval cuts in comparison with the VISX S4 group, and the difference between the programmed (6.0 mm) and topographic diameters was significant in both groups.
Conclusions
There was a difference between the programmed and postoperative topographic diameters of the ablation zone. The postoperative ablation zone differed in shape and size according to the type of excimer laser.
Similar content being viewed by others
Log in or create a free account to read this content
Gain free access to this article, as well as selected content from this journal and more on nature.com
or
References
Hersh PS, Stulting RD, Steinert RF, Waring III GO, Thompson KP, O’Connell M et al. Result of phase 3 excimer laser photorefractive keratectomy for myopia. Ophthalmology 1997; 104: 1535–1553.
McDonald MB, Deitz MR, Frantz JM, Kraff MC, Krueger RR, Salz JJ et al. Photorefractive keratectomy for low-to-moderate myopia and astigmatism with a small-beam, tracker-directed excimer laser. Ophthalmology 1999; 106: 1481–1489.
Pop M, Payette Y . Photorefractive keratectomy versus laser in situ keratomileusis: a control-matched study. Ophthalmology 2000; 107: 251–257.
Litwak S, Zadok D, Garcia-de Quevedo V, Robledo N, Chayet AS . Laser-assisted subepithelial keratectomy versus photorefractive keratectomy for the correction of myopia: a prospective comparative study. J Cataract Refract Surg 2002; 28: 1330–1333.
Tahzib NG, Bootsma SJ, Eggink FA, Nabar VA, Nuijts RM . Functional outcomes and patient satisfaction after laser in situ keratomileusis for correction of myopia. J Cataract Refract Surg 2005; 31: 1943–1951.
Schallhorn SC, Kaupp SE, Tanzer DJ, Tidwell J, Laurent J, Bourque LB . Pupil size and quality of vision after LASIK. J Cataract Refract Surg 2003; 110: 1606–1614.
Fan-Paul NI, Li J, Miller JS, Florakis GJ . Night vision disturbances after corneal refractive surgery. Surv Ophthalmol 2002; 47: 533–546.
Macsai MS, Stubbe K, Beck AP, Ravage ZB . Effect of expanding the treatment zone of the Nidek EC-500 laser on laser in situ keratomileusis outcomes. J Cataract Refract Surg 2004; 30: 2336–2343.
Pop M, Payette Y . Risk factors for night vision complaints after LASIK for myopia. Ophthalmology 2004; 111: 3–10.
Canals M, Elies D, Costa-vila J, Coret A . Comparative study ablation profiles of six different excimer lasers. J Refract Surg 2004; 20: 106–109.
Partal AE, Manche EE . Diameters of topographic optical zone and programmed ablation zone for laser in situ keratomileusis for Myopia. J Refract Surg 2003; 19: 528–533.
Kim EK, Lee DH, Park JW, Chu YK, Seo KY . New fixation device for photorefractive surgery and its effect on corneal epithelial wound healing. J Refract Surg 1999; 15: 594–601.
Mulhem MG, Foley-Nolan A, O’Keefe M, Condon PI . Topographical analysis of ablation centration after excimer laser photorefractive keratectomy and laser in situ keratomileusis for high myopia. J Cataract Refract Surg 1997; 23: 488–494.
Tsai YY, Lin JM . Ablation centration after active eye-tracker-assisted photorefractive keratectomy and laser in situ keratomileusis. J Cataract Refract Surg 2000; 26: 28–34.
Giaconi JA, Manche EE . Ablation centration in myopic laser in situ keratomileusis comparing the VISX S3 Active Trak and the VISX S2. J Cataract Refract Surg 2003; 29: 1522–1529.
Coorpender SJ, Klyce SD, McDonald MB, Doubrava MW, Kim CK, Tan AL et al. Corneal topography of small-beam tracking excimer laser photorefractive keratectomy. J Cataract Refract Surg 1999; 25: 675–684.
Roberts CW, Koester CJ . Optical zone diameters for photorefractive corneal surgery. Invest Ophthalmol Vis Sci 1993; 34: 2275–2281.
Boxer Wachler BS, Huynh VN, El-Shiaty AF, Goldberg D . Evaluation of corneal functional optical zone after laser in situ keratomileusis. J Cataract Refract Surg 2002; 28: 948–953.
Holladay JT, Janes JA . Topographic changes in corneal asphericity and effective optical zone after laser in situ keratomileusis. J Cataract Refract Surg 2002; 28: 942–947.
Twa MD, Lembach RG, Bullimore MA, Roberts C . A prospective randomized clinical trial of laser in situ keratomileusis with two different lasers. Am J Ophthalmol 2005; 140: 173–183.
Author information
Authors and Affiliations
Corresponding author
Additional information
Presented as a poster at the 93rd Annual Meeting of the Korean Ophthalmological Society, Busan, Korea, April 2005. Conflict of interest: None. Financial interest: This work was supported by ‘GRRC’ project of Gyeonggi Provincial Government, Korea and by the ‘National Research Foundation of Korea (NRF) grant funded by the Korea government (MEST) (No.M1AQ19, 2009-0082186)’
Rights and permissions
About this article
Cite this article
Ahn, J., Yang, H., Lew, H. et al. Comparison of the topographic ablation zone after photorefractive keratectomy for myopia using two different excimer lasers. Eye 24, 553–557 (2010). https://doi.org/10.1038/eye.2009.169
Received:
Revised:
Accepted:
Published:
Issue date:
DOI: https://doi.org/10.1038/eye.2009.169
Keywords
This article is cited by
-
Six modes of corneal topography for evaluation of ablation zones after small-incision lenticule extraction and femtosecond laser-assisted in situ keratomileusis
Graefe's Archive for Clinical and Experimental Ophthalmology (2020)
