Laser in situ keratomileusis in 2012: a review.

Laser in situ keratomileusis (LASIK) is a safe and effective treatment for refractive error. A combination of technological advances and increasing surgeon experience has served to further refine refractive outcomes and reduce complication rates. In this article, we review LASIK as it stands in late 2012: the procedure, indications, technology, complications and refractive outcomes.

[Update on fs laser technology in ophthalmology]. / Update Femtosekundenlaser-Technologien in der Augenheilkunde.

Femtosecond (fs) lasers for LASIK flap creation have increased their market share from 0 percent in 2001 to over 55 percent in 2010. Now, in cataract surgery a similar revolution may take place. What makes this technology so special and which new areas of surgery will furthermore be entered in the future? This review elucidates the most important technical features of the fs lasers and interaction processes with the tissue. This understanding is intended to provide a better overview of the current market situation on the one hand. In addition, it can be estimated what kind of short- and long-term development this technology could take in the future.

Gauging interest of the general public in laser-assisted in situ keratomileusis eye surgery.

PURPOSE: To assess interest among members of the general public in laser-assisted in situ keratomileusis (LASIK) surgery and how levels of interest in this procedure have changed over time in the United States and other countries. METHODS: Using the Google Trends Web site, we determined the weekly frequency of queries involving the term "LASIK" from January 1, 2007, through January 1, 2011, in the United States, United Kingdom, Canada, and India. We fit separate regression models for each of the countries to assess whether residents of these countries differed in their querying rates on specific dates and over time. Similar analyses were performed to compare 4 US states. Additional regression models compared general public interest in LASIK surgery before and after the release of a 2008 Food and Drug Administration report describing complaints associated with this procedure. RESULTS: During 2007 to 2011, the Google query rate for "LASIK" was highest among persons residing in India, followed by the United Kingdom, Canada, and the United States. During this time period, the query rate declined by 40% in the United States, 24% in India, and 22% in the United Kingdom, and it increased by 8% in Canada. In all 4 of the US states examined, the query rate declined-by 52% in Florida, 56% in New York, 54% in Texas, and 42% in California. Interest in LASIK declined further among US citizens after the Food and Drug Administration report release. CONCLUSIONS: Interest among the general public in LASIK surgery has been waning in recent years.

Trends in refractive surgery at an academic center: 2007-2009.

BACKGROUND: The United States officially entered a recession in December 2007, and it officially exited the recession in December 2009, according to the National Bureau of Economic Research. Since the economy may affect not only the volume of excimer laser refractive surgery, but also the clinical characteristics of patients undergoing surgery, our goal was to compare the characteristics of patients completing excimer laser refractive surgery and the types of procedures performed in the summer quarter in 2007 and the same quarter in 2009 at an academic center. A secondary goal was to determine whether the volume of astigmatism- or presbyopia-correcting intraocular lenses (IOLs) has concurrently changed because like laser refractive surgery, these "premium" IOLs involve out-of-pocket costs for patients. METHODS: Retrospective case series. Medical records were reviewed for all patients completing surgery at the Wilmer Laser Vision Center in the summer quarter of 2007 and the summer quarter of 2009. Outcome measures were the proportions of treated refractive errors, the proportion of photorefractive keratectomy (PRK) vs. laser-assisted in-situ keratomileusis (LASIK), and the mean age of patients in each quarter. Chi-square test was used to compare the proportions of treated refractive errors and the proportions of procedures; two-tailed t-test to compare the mean age of patients; and two-tailed z-test to compare proportions of grouped refractive errors in 2007 vs. 2009; alpha = 0.05 for all tests. Refractive errors were grouped by the spherical equivalent of the manifest refraction and were considered "low myopia" for 6 diopters (D) of myopia or less, "high myopia" for more than 6 D, and "hyperopia" for any hyperopia. Billing data were reviewed to obtain the volume of premium IOLs. RESULTS: Volume of laser refractive procedures decreased by at least 30%. The distribution of proportions of treated refractive errors did not change (p = 0.10). The proportion of high myopes, however, decreased (p = 0.05). The proportions of types of procedure changed, with an increase in the proportion of PRK between 2007 and 2009 (p = 0.02). The mean age of patients did not change [42.4 ± 14.4 (standard deviation) years in 2007 vs. 39.6 ± 14.5 years in 2009; p = 0.4]. Astigmatism-correcting IOL and presbyopia-correcting IOL volumes increased 15-fold and three-fold, respectively, between 2007 and 2009. CONCLUSIONS: Volume of excimer laser refractive surgery decreased by at least 30% between 2007 and 2009. No significant change in mean age or in the distribution of refractive error was seen, although the proportion of high myopes decreased between summer quarters of 2007 and 2009. PRK gained as a proportion of total cases. Premium IOL volume increased, but still comprised a very small proportion of total IOL volume.

Laser epithelial keratomileusis in 2010 - a review.

Photorefractive keratectomy, laser epithelial keratomileusis (LASEK) and Epi-LASIK are all variants of a similar type refractive surgery involving laser on the surface of the cornea and differ mainly in management of the epithelium. Although laser in situ keratomileusis (LASIK) is currently the most popular form of refractive surgery, LASEK is the procedure of choice in some patients. We highlight potential complications of LASEK and how these may be managed. Following laser refractive surgery, corneal thickness is reduced, which has implications for intraocular pressure measurement and glaucoma screening and management. This is particularly important following surface laser procedures where no evidence of previous surgery may be visible. In the event that cataract surgery is required at a later date, correct calculation of the appropriate intraocular lens power can be difficult and it thus important that patients are given their preoperative keratometry readings and refraction. Compared with LASIK patients, those who undergo LASEK are considered to be at lower risk of corneal ectasia. Improved understanding of wound healing post LASEK and better postoperative pain management are ongoing challenges.

Laser in situ keratomileusis in 2010 - a review.

Laser in situ keratomileusis has become a widely accepted and commonly performed surgical refractive procedure. With the rapid advances in laser technology and surgical techniques, the visual outcomes and safety of this procedure has significantly improved. This review outlines the historical background, recent technological advances, indications, patient assessment and selection, the surgical technique, as well as complications of the procedure and their management.

Cataract and refractive surgery in ; a survey of KSCRS members from 1995~2006.

PURPOSE: This purpose of this report was to study trends in cataract and refractive surgeries conducted during the past twelve years and to compare results to previous reports from the ASCRS and New Zealand (NZ) in order to forecast future medical services. METHODS: We surveyed members of the Korean Society of Cataract and Refractive Surgery (KSCRS) every year from 1995 to 2006, and studied changes in cataract and refractive surgeries (RS). RESULTS: The duration of hospitalization has been gradually decreasing to the point that a one day hospitalization following surgery has become common. The rate of topical anesthesia use has significantly increased since 1998. Sutureless incision methods are now commonly practiced. The use of acryl IOL as an optic material has been gradually increasing for cataract surgeries. KSCRS members showed an interest in the special intraocular lenses as multifocal IOL. While Excimer laser PRK was the most popular refractive surgery during the first stage, KSCRS members increasingly prefer LASIK to the Excimer laser PRK. Regression of the corrected visual acuity, dry eye, night halo, and flashes were the most common complications following refractive surgeries. Medical disputes related to PRK and LASIK have been gradually increasing throughout the study period. CONCLUSIONS: We confirm that the KSCRS practice styles for cataract and RS are similar to those of the ASCRS and NZ. We infer a world-wide trend from the comparison of these three societies.

The next generation of LASIK patients.

PURPOSE OF REVIEW: With baby boomers aging, and despite a growing global population, there is a decreasing number of potential laser vision correction patients. Some believe that the worldwide economic downturn of these times will limit the number of potential patients as well. This article highlights looking to an alternative segment of the population to identify potential laser vision correction patients and the limitations of reaching this group. RECENT FINDINGS: The group known as generation Y contains a large number of individuals who may be candidates for laser vision correction. Traditional marketing efforts present challenges in reaching this particular population segment. Many individuals in this group are already patients of eye doctors for contact lenses and glasses and can be reached by these eye doctors to address candidacy and education of laser vision correction. SUMMARY: Generation Y represents a large population segment that contains technology-embracing individuals who, although hard to reach with traditional marketing efforts, may be reached by fellow eye doctors already managing these patients. There are many in this age group who would be good laser vision correction candidates.

A comparison of wavefront-optimized and wavefront-guided ablations.

PURPOSE OF REVIEW: Optimized aspherical as well as custom wavefront-guided treatments attempt to reduce the induction of visually disturbing aberrations than can occur with conventional spherocylindrical corneal ablation. This review highlights a comparison of the advances and limitations of the two treatments. RECENT FINDINGS: Optimized aspherical as well as wavefront-guided corneal excimer laser treatments have continued to improve in outcomes compared with conventional treatments. Wavefront-guided as well as wavefront-optimized treatments yield high predictability, efficacy, and safety. Equally good vision has been obtained as measured by snellen acuity, patient questionnaires, and total residual higher-order aberrations. Wavefront-guided treatments did have better results in spherical aberration, coma as well as contrast sensitivity outcomes. Surgeons who have easy access to both technologies suggest using wavefront-optimized treatments in 67-88% of patients and reserve wavefront-guided treatments for those who have above average higher-order aberrations. However, even with individually adjusted aspheric, 'Q' values, optimized ablations still increased higher-order aberrations and wavefront-guided treatments also did not achieve the elimination of residual higher-order aberrations. SUMMARY: Optimized aspheric corneal ablations that attempt to avoid reducing the prolate eccentricity of the average cornea as well as wavefront-guided treatments that attempt to reduce the individual whole-eye aberrations have continued to improve visual outcomes compared with conventional treatments.

Laser refractive surgery in the United States Navy.

PURPOSE OF REVIEW: The aim of this article is to highlight the numerous contributions the US Navy has made to the field of laser refractive surgery. It summarizes and draws together published papers, national meeting presentations, and unpublished data of clinical and laboratory studies involving the excimer laser and the laser-assisted in-situ keratomileusis (LASIK) flap. RECENT FINDINGS: Photorefractive keratectomy (PRK) is the most widely performed refractive procedure in the US Navy, but this trend is slowly changing as femtosecond laser-assisted LASIK becomes more widely performed. Based on the results of recent studies, PRK is approved for designated Naval aviators and flight officers; post-PRK students are now allowed into flight training. Wavefront-guided PRK and LASIK are more predictable and provided better results than conventional PRK and LASIK. Femtosecond laser-assisted LASIK is now a waiverable procedure for US military personnel and US Astronauts (excluding Naval aviators, as of this writing). SUMMARY: Since its personnel must meet strict visual requirements to accomplish their mission in a variety of environments, the US Navy places particular emphasis on safety and quality of vision after laser refractive surgery. The US Navy has been evaluating the safety and efficacy of laser refractive surgery since 1993 and will continue to do so.

Current trends in advanced surface ablation.

PURPOSE OF REVIEW: Since their introduction in the mid-1990s, surface ablation techniques have continued to evolve, enabling surgeons to give patients better quality of vision with less postoperative pain. The purpose of this chapter is to discuss that evolution, the common techniques used today, and how to address potential complications. RECENT FINDINGS: Advanced surface ablation techniques offer advantages over laser in situ keratomileusis, including expanded potential patient profiles, reduced haze and pain postoperatively, and increased quality of vision. Haze reduction via preserved epithelial flaps, smoother stromal beds, and introduction of mitomycin-C intraoperatively have all improved safety outcomes of advanced surface ablation. SUMMARY: Experience has shown us that virtually all patients who are candidates for laser in situ keratomileusis can be candidates for surface ablation, but patients with specific ocular conditions, such as epithelial basement membrane dystrophy, superficial corneal scars, and previous radial keratotomy will have the best outcomes with surface ablation. Surface ablation and laser in situ keratomileusis are comparable in terms of safety and quality of vision. Wavefront-guided photorefractive keratectomy offers better acuity and less induction of higher order aberrations than wavefront-guided laser in situ keratomileusis.

Advances in technologies for laser-assisted in situ keratomileusis (LASIK) surgery.

Laser-assisted in situ keratomileusis (LASIK) has become the most widely used form of refractive surgery today. The objective of this surgical technique is to modify the anterior corneal shape by ablating tissue from the stroma by means of the excimer laser after creating a hinged corneal flap. This way, we are able to change the refractive status of the patient, providing better unaided vision. Continuous improvements in the original technique have made the surgical procedure safer, more accurate and repeatable. These progressions are due to the development of novel technologies that are the responsible for new surgical instrumentation, which makes the surgical procedure easier for the surgeon, and better excimer laser ablation algorithms, which increase the optical quality of the ablation and thus the safety of the vision correction procedure. This article aims to describe the more relevant advances in LASIK that have played an important role in the spread and popularity of this technique.

[Application of wavefront analysis in clinical and scientific settings. From irregular astigmatism to aberrations of a higher order--Part II: examples]. / Anwendung der Wellenfrontanalyse in Klinik und Wissenschaft : Vom irregulären Astigmatismus zu Aberrationen höherer Ordnung--Teil II: Beispiele.

In recent years, wavefront analysis has ceased to be purely a laboratory application and emerged as a method used in ophthalmological diagnosis. This development has been promoted mainly by the widespread use of wavefront-guided LASIK (laser in situ keratomileusis). However, aberrometry is still not a common diagnostic technique, and for many ophthalmologists interpretation of the results is difficult. The second part of this serial paper reviews findings that are relevant for the ophthalmological community and highlights current scientific applications in this area.

Preoperative characteristics of patients undergoing LASIK in 1997 versus 2004 at one surgical eye center in China.

PURPOSE: To compare the preoperative characteristics of LASIK patients undergoing surgery in 1997 versus 2004 at one of the principal eye surgical centers in China. METHODS: Preoperative data of patients who underwent LASIK in 1997 and 2004 were recorded and retrospectively compared. RESULTS: In 1997, the mean spherical equivalent refraction of the 824 eyes of 428 patients undergoing LASIK surgery was -7.30 +/- 4.65 diopters (D), with a mean patient age of 24.67 +/- 6.76 years. Students represented 45.05% of patients undergoing surgery in 1997. In 2004, the mean spherical equivalent refraction of the 8434 eyes of 4286 patients undergoing LASIK surgery was -6.66 +/- 3.31 D, with a mean patient age of 25.20 +/- 6.59 years. Students represented >50% of patients undergoing surgery in 2004. There were significant differences in the constitution ratio of occupation and the spherical equivalent refractions between 1997 and 2004 (t=-2.712, chi-squared=25.117, respectively, P<.05). CONCLUSIONS: At our center in China, the majority of LASIK patients are young and have myopia ranging from -3.00 to -10.00 D. Students were much more likely than any other occupation to undergo LASIK. The number of patients undergoing LASIK at our center in China has increased exponentially from 1997 to 2004, with an average annual increase in surgical volume of approximately 40%.

US trends in refractive surgery: 2003 ISRS/AAO survey.

PURPOSE: To determine the latest trends in refractive surgery in the United States. METHODS: All U.S. members of the International Society of Refractive Surgery of the American Academy of Ophthalmology were mailed the 2003 refractive surgery survey dealing with volumes, types, preferences of refractive surgery performed, and use of new emerging technology. Questions regarding radial keratotomy (RK), astigmatic keratotomy (AK), limbal relaxing incisions (LRI), photorefractive keratectomy (PRK), laser in situ keratomileusis (LASIK), laser subepithelial keratomileusis (LASEK), intracorneal ring segments (ICRS), laser thermokeratoplasty (LTK), conductive keratoplasty (CK), phakic intraocular lenses (PIOL), clear lens extractions (CLE), and scleral expansion (SE) procedures were examined in the survey. Use of lasers, microkeratomes, pupillometry instruments, postoperative medications, wavefront analyzers, topographers, etc were examined. RESULTS: In 2003, LASIK continued to dominate for refractive errors between -8.00 to +3 diopters. Surgeons are waiting on the PIOL for high myopes and are performing CLE for high hyperopes. Photorefractive keratectomy, LASIK, LASEK, CLE, PIOL, and CK appeared to have bright futures; whereas, RK, ICR, LTK and SE were on the decline. Bilateral LASIK at the same surgical session is offered by 98% of surgeons. VISX lasers are used 2:1 over all other lasers in the United States. Zeiss-Humphrey still dominates topographers at 37%. The Bausch & Lomb Hansatome (48%) leads microkeratomes. Surgeons are charging, on average, 300-500 dollars more per eye for custom ablations and these ablations have already been accepted and integrated into refractive practices. Comanaging of refractive surgery patients is significantly down from previous years. Fourth-generation fluoroquinolones overtook the postoperative antibiotic prescriptions, with prednisolone and fluoromethalone dominating as anti-inflammatories. CONCLUSIONS: Trends and changes as refractive surgery grows in the mainstream of ophthalmology in the United States continue to be elucidated by this professional organization survey.

Refractive surgery in the United States Army, 2000-2003.

PURPOSE: To examine the history, current status, outcomes, and future direction of the Army Warfighter Refractive Eye Surgery Program (WRESP), which was established to reduce the limitations posed by corrective eyewear in combat arms soldiers. DESIGN: Retrospective study. PARTICIPANTS: Sixteen thousand one hundred eleven Army service members who underwent refractive surgery between May 2000 and September 2003. METHODS: Results were collected from monthly WRESP reports and from questionnaires administered to refractive surgery patients returning from deployments to southwest Asia. Soldiers rated the impact of refractive surgery on their ability to perform select operational tasks as well as their overall readiness. MAIN OUTCOME MEASURES: Visual acuity (VA) and patient satisfaction. RESULTS: Between May 2000 and September 30, 2003, 32 068 eyes of 16 111 soldiers were treated. Postoperative uncorrected VA was better than or equal to 20/20 in 85.6%, 20/25 in 92.4%, and 20/40 in 98.2% of eyes with at least 3 months' follow-up, and 93.7% of 175 surveyed patients rated their overall readiness better or much better after surgery. CONCLUSIONS: This program has provided excellent outcomes and enhanced the overall readiness of over 16 000 Army service members. Reports of night vision difficulties, LASIK flap dislocation, and dry eye are infrequent, and do not seem to have a significant negative impact on military operations or individual readiness. This article contains additional online-only material available at http://www.ophsource.com/periodicals/ophtha.