There has been a lot of press regarding the safety and efficacy of LASIK. The following is an abstract from the latest issue of Ophthalmology.
Received 28 March 2008; received in revised form 28 March 2008; accepted 8 April 2008.
To describe wavefront-guided (WFG) LASIK for the primary treatment of low to moderate levels of myopia and astigmatism and to examine the evidence on the safety and effectiveness of the procedure in comparison with conventional LASIK.
Literature searches conducted in 2004, 2005, 2006, and 2007 retrieved 209 unique references from the PubMed and Cochrane Library databases. The panel selected 65 articles to review, and of these, chose 45 articles that they considered to be of sufficient clinical relevance to submit to the panel methodologist for review. During the review and preparation of this assessment, an additional 2 articles were included. A level I rating was assigned to properly conducted, well-designed, randomized clinical trials; a level II rating was assigned to well-designed cohort and case-controlled studies; and a level III rating was assigned to case series, case reports, and poorly designed prospective and retrospective studies. In addition, studies that were conducted by laser manufacturers before device approval (premarket approval) were reviewed as a separate category of evidence.
The assessment describes studies reporting results of WFG LASIK clinical trials, comparative trials, or both of WFG and conventional LASIK that were rated level II and level III. There were no studies rated as level I evidence. Four premarket approval studies conducted by 4 laser manufacturers were included in the assessment. The assessment did not compare study results or laser platforms because there were many variables, including the amount of follow-up, the use of different microkeratomes, and the level of preoperative myopia and astigmatism.
There is substantial level II and level III evidence that WFG LASIK is safe and effective for the correction of primary myopia or primary myopia and astigmatism and that there is a high level of patient satisfaction. Microkeratome and flap-related complications are not common but can occur with WFG LASIK, just as with conventional LASIK. The WFG procedure seems to have similar or better refractive accuracy and uncorrected visual acuity outcomes compared with conventional LASIK. Likewise, there is evidence of improved contrast sensitivity and fewer visual symptoms, such as glare and halos at night, compared with conventional LASIK. Even though the procedure is designed to measure and treat both lower- and higher-order aberrations (HOAs), the latter are generally increased after WFG LASIK. The reasons for the increase in HOA are likely multifactorial, but the increase typically is less than that induced by conventional LASIK. No long-term assessment of WFG LASIK was possible because of the relatively short follow-up (12 months or fewer) of most of the studies reviewed.
Nov. 7, 2008 American Academy of Ophthalmolgy Meeting
ATLANTA — In the literature, 95% of myopic patients are achieving uncorrected visual acuity of 20/20 after custom laser vision correction, a surgeon said here. In custom hyperopic patients, similar success is being reported in 70% to 80% of cases.
"In the old days, 7 years ago, we were seeing maybe 95% 20/40 or better uncorrected. So there's a shift in terms of our accuracy," Scott MacRae, MD, said during Refractive Surgery Subspecialty Day preceding the American Academy of Ophthalmology meeting.
The current limits of myopic treatment are 10 D to 12 D of myopia, depending on corneal thickness, age and pupil size.
Current limits of hyperopic treatment are 4 D to 6 D of hyperopia. These cases are more likely than myopia cases to regress, he said.
In high levels of hyperopia, especially in patients older than 15 years, a surgeon can consider doing a clear lens extraction, Dr. MacRae said.
Instead of lifting the LASIK flap, refractive surgeons can treat most moderate epithelial ingrowth and restore patients’ lost visual acuity with a treatment tool commonly used by cataract surgeons, the Nd:YAG laser. This low-energy, effective procedure uses the workhorse of ophthalmic lasers to spare patients more invasive surgery and avoid the risks of further complications from a flap lift
Fenretinide, in development for the treatment of geographic atrophy (GA) associated with age-related macular degeneration (AMD), has received fast track designation from the Food and Drug Administration (FDA) after the agency analyzed the compound’s interim Phase II results, developer Sirion Therapeutics (Tampa, Fla.) said in a press release. The Phase II study compared the growth rate of GA lesions, as measured by retinal photography, in patients treated with daily doses of placebo or 100mg or 300mg of oral fenretinide, Sirion said. These data showed slower growth of the GA lesions for the 300mg dose for all lesion sizes at entry. This trend was evident as early as 6 months and increased over time. According to the company, fenretinide is an oral vitamin A binding protein antagonist believed to halt the accumulation of retinol (vitamin A) toxins through affinity for retinol-binding protein. It is also believed to slow the formation and accumulation of toxic byproducts thought to be responsible for vision loss in conditions such as GA.
June 29, 2009
A common questin asked by my patients is "How long will my LASIK last?" The short answer is: forever for most people. This doesn't mean that you will always be 20/20. People's prescriptions change somewhat throughout life but most people will find reduced or no dependence on their glasses for many years after LASIK. A recent study published in Refractive Surgery bears this out. The authors tracked down a group of patients 14 years after laser vision correction. The majority of patients were still satisfied with their vision and their decision to have corrective eye surgery. I would expect with today's improved technology that if the same survey were conducted 14 years after LASIK performed now, the positive responses would be even higher.
We have recently updated and expanded our practice website. For information on cataracts, intacts, refractive surgery or other services offered by Dr. Dean Dornic go to www.eyespecialistsofcarolina.com
Femtosecond SBK and LASEK safely and effectively corrected myopia, according to a study.
However, femtosecond laser sub-Bowman's keratomileusis (SBK) yielded somewhat better visual and refractive outcomes at 3 months after surgery, the study authors said.
The retrospective case series included 2,108 eyes. A total of 1,072 eyes were treated with femtosecond SBK and 1,036 eyes received LASEK with or without mitomycin C. SBK patients had a mean age of 31.03 years; LASEK patients had a mean age of 30.5 years.
The investigators conducted examinations at 1 day, 1 week, and 1 and 3 months after surgery. Eyes with a significant loss in best corrected visual acuity at 3 months underwent another examination at 6 months.
Surgeons used the Schwind Esiris excimer laser to perform SBK and LASEK. A LASIK nomogram was used in SBK, and a PRK nomogram was used in LASEK.
At 1 day postop, mean uncorrected visual acuity was 0.92 in the SBK eyes and 0.62 in the LASEK eyes. At 1 week, it was 0.98 in SBK eyes and 0.78 in LASEK eyes; at 1 month, 0.96 in SBK eyes and 0.91 in LASEK eyes; and at 3 months, 1.06 in SBK eyes and 1.03 in LASEK eyes. The differences were statistically significant at each interval up to 3 months (P < .01 for all comparisons).
At 3 months, mean BCVA was 1.13 in SBK eyes and 1.10 in LASEK eyes. Twenty eyes in the LASEK group and nine eyes in the SBK group had lost two or more lines of BCVA.
After LASEK, loss of BCVA was attributed to haze in two eyes; no SBK eyes had clinically significant haze.
"More studies with longer follow-up and studies dealing with the biomechanical response of the cornea are needed to further elucidate whether [femtosecond] SBK could be really considered an alternative to [surface ablation]," the authors said.
SBK and Advanced Surface Ablation procedures are quickly replacing LASEK as the preferred techniques when LASIK is not a good option.
There is no such thing as a medical procedure that is 100% guaranteed. Individual risk vary so please discuss your chance of success with your LASIK surgeon before proceeding.
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