This article is more than 5 years old. Information may no longer be current.
LASIK, IOLs each have different strengths for correction of residual refractive error
A retrospective study looked at the indications and outcomes for both refractive approaches.
LASIK or lens-based methods may be used in correcting residual refractive error after cataract surgery, according to recent study data.
LASIK was more flexible and offered more specific refractive targets than lens-based methods. IOL exchange and piggyback lens implantation were preferable when correction was desired soon after cataract surgery, according to the study authors.
George J.C. Jin, MD, PhD, and colleagues published their findings in the Journal of Cataract and Refractive Surgery.
In a telephone interview with Ocular Surgery News, Dr. Jin said the study was the first to compare LASIK with lens-based methods.
“Also, we’re dealing with different refractive errors. For example, we analyzed myopia, hyperopia and mixed astigmatism after cataract surgery. Different treatment methods have different results,” Dr. Jin said.
LASIK proved effective in treating mixed astigmatism, which cannot be corrected with lens-based methods, the authors noted.
“The major point for LASIK is dealing with astigmatism and mixed astigmatism because in our population, almost 30% of mixed astigmatism patients were treated with LASIK,” Dr. Jin said.
Patients and procedures
The retrospective study included 57 eyes of 48 patients; all eyes initially underwent phacoemulsification with posterior chamber IOLs.
Enhancement was considered for patient dissatisfaction, anisometropia, ametropia, contact lens intolerance or inability to wear spectacles. Patients with initial surgery other than phacoemulsification or evidence of corneal and other ocular pathologies were excluded.
Twenty-eight eyes underwent LASIK and 29 had lens-based surgery. The LASIK patients had a mean age of 62.1 years; mean age of the lens-based procedure patients was 59.6 years, the study authors said.
In the LASIK group, 19 eyes were myopic, eight eyes were treated for mixed astigmatism and one for hyperopic. Seventy-eight percent of LASIK eyes underwent the procedure 6 months or longer after initial cataract surgery.
In the lens-based group, 12 eyes were myopic and 17 eyes were hyperopic, and none were treated for mixed astigmatism. Sixty-two percent of lens-based procedures were performed within 3 months of the initial surgery, the authors wrote.
Among the eyes undergoing lens-based surgery, 21 (72%) had IOL exchange and eight (28%) were implanted with piggyback IOLs.
Primary outcomes for both groups included uncorrected visual acuity, best corrected visual acuity, manifest refractive spherical equivalent, refractive cylinder and complications.
Efficacy was defined as the percentage of eyes with a postoperative UCVA of 20/20 and 20/40 or better. Safety was defined as complications and the number of lines of BCVA changed from the preoperative level in each eye at final follow-up.
Predictability was assessed by calculating the number of eyes with a postoperative spherical equivalent within 0.5 D to 1 D of targeted correction.
Outcomes were assessed at a mean follow-up of 20 to 24 months.
In cases involving IOL exchange and piggyback IOL implantation, the Holladay I formula was used to make IOL power calculations.
Dr. Jin stressed the need to make accurate, individualized IOL calculations.
Visual acuity and refraction
Among the LASIK eyes, mean logMAR UCVA improved from 0.59 ± 0.42 preoperatively to 0.11 ± 0.11 at final follow-up (P < .001). Among the lens-based eyes, mean logMAR UCVA improved from 0.92 ± 0.44 to 0.20 ± 0.15, the authors reported.
After refractive surgery, 38% of the LASIK eyes and 11% of the lens-based eyes had UCVA of 20/20; 96% of LASIK eyes and 93% of lens-based eyes attained UCVA of 20/40 or better.
Overall, the LASIK eyes had better postoperative logMAR UCVA than the lens-based eyes. Neither group experienced intraoperative complications, and no eyes in either group lost more than one line of BCVA; all eyes had postoperative BCVA of 20/40 or better, the authors reported.
Dr. Jin called for tempering patients’ expectations for postop UCVA.
“Older age is a main factor when compared to LASIK for the refractive surgery patient,” he said. “Although ophthalmologists are under ever-increasing pressure to achieve 20/20 vision … UCVA of 20/30 or 20/40 might be a more realistic goal.”
For more information:
- George J.C. Jin, MD, PhD, can be reached at the Eye Institute of Utah, 755 E. 3900 South, Salt Lake City, UT 84107; e-mail: georgejin@hotmail.com.
Reference:
- Jin GJC, Merkley KH, Crandall AS, Jones YJ. Laser in situ keratomileusis versus lens-based surgery for correcting residual refractive error after cataract surgery. J Cataract Refract Surg. 2008;34:562-569.
- Matt Hasson is an OSN Staff Writer who covers all aspects of ophthalmology. He focuses on regulatory, legislative and practice management topics.