Conventional versus custom ablation in photorefractive keratectomy: Randomized clinical trial
- 1 April 2010
- journal article
- research article
- Published by Ovid Technologies (Wolters Kluwer Health) in Journal of Cataract & Refractive Surgery
- Vol. 36 (4), 637-643
- https://doi.org/10.1016/j.jcrs.2009.10.050
Abstract
To compare visual outcomes and changes in total higher-order aberrations (HOAs) between conventional photorefractive keratectomy (PRK) and custom PRK Department of Ophthalmology, Labbafinejad Medical Center, Ophthalmic Research Center, Shahid Beheshti University of Medical Sciences and Negah Eye Center, Tehran, Iran. This clinical trial comprised eyes having bilateral myopic PRK with the Technolas 217z excimer machine. One eye had conventional ablation (conventional group) and the other eye, wavefront-guided custom treatment (custom group). Changes in postoperative visual acuity, cycloplegic refraction, contrast sensitivity function, and root mean square higher-order aberrations (RMS HOAs) were compared between the 2 groups. The mean age of the 28 patients (56 eyes) was 26.7 years. The mean preoperative cycloplegic spherical equivalent refractive error was −4.92 diopters (D) ± 1.6 (SD) and the mean refractive astigmatism, 0.91 ± 1.0 D. There was no statistically significant difference between the 2 groups in preoperative cycloplegic refractive error, HOAs, or contrast sensitivity function. The mean follow-up was 8.1 ± 3.3 months. The increase in RMS HOAs from preoperatively to postoperatively was statistically significantly higher in the custom group in the 6.0 mm zone (P = .03) but not in the 4.0 mm zone (P = .26). The decrease in low mesopic contrast sensitivity function was statistically significant in both groups. The RMS HOAs significantly increased after PRK with both methods. The results suggest that custom ablation is more sensitive to optical zone (OZ) size and may yield more aberrations with an OZ smaller than 6.0 mm. No author has a financial or proprietary interest in any material or method mentioned.Keywords
This publication has 23 references indexed in Scilit:
- Effect of NIDEK Optimized Aspheric Transition Zone Ablation Profile on Higher Order Aberrations During LASIK for MyopiaJournal of Refractive Surgery, 2009
- Patient satisfaction and visual symptoms after laser in situ keratomileusisOphthalmology, 2003
- Laser in situ keratomileusis for myopia and astigmatism: safety and efficacy: A report by the American Academy of OphthalmologyOphthalmology, 2002
- Wavefront guided ablationAmerican Journal of Ophthalmology, 2001
- Increased higher-order optical aberrations after laser refractive surgeryJournal of Cataract & Refractive Surgery, 2001
- Visual Performance After Photorefractive KeratectomyAmerican Journal of Ophthalmology, 1996
- Experimental Verification of Computational Methods to Calculate Magnification in Refractive SurgeryAmerican Journal of Ophthalmology, 1995
- Measurement of monochromatic ocular aberrations of human eyes as a function of accommodation by the howland aberroscope techniqueVision Research, 1995
- Magnification and Visual Acuity in Refractive SurgeryAmerican Journal of Ophthalmology, 1993
- Calculating the surgically induced refractive change following ocular surgeryJournal of Cataract & Refractive Surgery, 1992