SPECIAL REPORT: LASIK AT 25 YEARS

LASIK, 25 years in the making

The refractive error corrector is likely back; here’s why.

By Christine Bahls, executive editor

There is much to read about LASIK these days. Not just on PubMed, but in the consumer press as well. And unlike in times past, much about this refractive surgery is positive.

It’s fair to say a confluence of reasons has made these articles materialize: patient satisfaction surveys, meta-analyses — in fact, a slew of PubMed listings in just the past year — and consumer articles that have begat more consumer articles — have brought LASIK into the limelight again.

Actual procedure numbers, according to Kristen Ingenito, market analyst for Market Scope, are expected to be modest, in the single digit area, for 2016 over 2015. (See below)

What has spurred the more positive outcomes? Better clinical understanding of the issues, for one. (See adjacent articles)

“LASIK is now 25 years old,” says Stephen Slade, MD, who ought to know. “The technology has come a long way, with notable advances like scanning lasers, eye trackers, femtosecond laser, keratomes and advanced ablation patterns.

“We have also greatly improved our avoidance and treatment of complications including ectasia, dry eye and poor quality of vision,” says Dr. Slade, a LASIK pioneer.

Market Scope expects single digit growth for this year. Also, volume for Q1-2016 laser refractive procedures (including LASIK and surface ablation) increased 16.5% quarter to quarter from Q4-2015’s tally, according to Market Scope’s Q1-2016 Survey of Cataract and Refractive Surgeons.
[source: Market Scope Q1-2016 Survey of Ophthalmic Surgeons]

Oh the tangled web …

Physicians might want to know what patients are reading on the web about LASIK. These articles are all recent.

The Huffington Post advises how to get the procedure performed more cheaply; a San Antonio-based piece lists the number of Spurs who have had the surgery; and on the website empowHer readers are told about 13 problems that would lead to poor outcomes — dry eye, blepharitis and large pupils included. No question, consumer web sites are talking LASIK.

OMIC claims

The Ophthalmic Mutual Insurance Company shows on its website that the last comparison of LASIK with other types of indemnity payments was 2011 — in other words, there weren’t enough claims filed in the ensuing years to make a meaningful comparison.

As for prior years: according to the 2008 OMIC Digest, “LASIK incidents peaked in 2000 and have been dropping ever since.” (For context, the OMIC had 286 cumulative refractive claims by 2008. The first refractive claim was made in 1989.)

What to say to patients

If web-savvy patients, interested in LASIK, ask you for good sites to get information, here are three:

• American Academy of Ophthalmology: http://tinyurl.com/gv7frcv

• American Refractive Surgery Council: https://americanrefractivesurgerycouncil.org/

• The FDA: http://tinyurl.com/z8zsry7

The learning curve

Steep? Perhaps. Both patient and physician have gained much.

By Marguerite McDonald, MD, FACS

One significant reason for the increased levels of post-LASIK patient satisfaction is our attention to the ocular surface preoperatively. Surgeons now have widespread appreciation for the impact of ocular surface disease, especially dry eye, on both the accuracy of preoperative measurements and postoperative quality of vision.

The prevalence of dry eye is even higher in patients seeking LASIK than in the general population because these patients, many of whom wear contact lenses, have dry eye — and they can no longer wear their contacts. LASIK surgeons now know to ask each candidate why they are seeking refractive surgery; if the answer is, “I can no longer wear contact lenses — they are uncomfortable,” this is a red flag that virtually always signals the presence of ocular surface disease.

Preoperative diagnosis

Besides a good history and slit lamp examination, LASIK surgeons now have an array of new, rapid in-office technologies to assist in diagnosing dry eye preoperatively. These include: tear osmolarity testing; detecting levels of matrix metalloproteinase9, a marker for inflammation in the tears; detecting automated tear film breakup time; meibography; and more.

Many surgeons also have learned that patients with dry eye will not decide against refractive surgery if they must be treated for a month before obtaining the critical preoperative measurements.

Dry eye treatments

Many LASIK candidates will opt for in-office OSD treatments in preparation for their LASIK surgery when properly educated of the benefits, and LASIK surgeons now have more effective ways to treat dry eye, including: topical and oral medications; in-office treatments to scrub eyelids or evacuate the meibomian glands; and improved artificial tear, gel and ointment formulations.

Preventing postoperative development

In Bower et al’s 2015 review of the incidence of chronic dry eye after PRK and LASIK in 140 active-duty U.S. Army personnel at 12 months postoperative, 5.0% of PRK and 0.8% of LASIK participants developed chronic dry eye.¹ Regression analysis showed that lower preoperative Schirmer scores significantly influencd development of chronic dry eye after PRK, whereas lower preoperative Schirmer scores or higher ocular surface staining scores significantly influenced the occurrence of chronic dry eye after LASIK. The authors concluded that chronic dry eye was uncommon after PRK and LASIK; discerning ocular surface and tear-film characteristics during preoperative examination might help to predict chronic dry-eye development in PRK and LASIK.

Even more promise

Current research could result in treatment(s) that drive the already low incidence of post-LASIK dry eye even lower. In 2015, Chao et al reviewed the structural and functional changes in corneal innervation after LASIK.² The authors studied 20 non-dry eye volunteers who underwent bilateral myopic LASIK to evaluate changes in nerve morphology, tear neuropeptide, and dry eye, to determine the relationship between re-innervation and dry eye, and to assess the role of tear neuropeptides in re-innervation post-LASIK. They monitored corneal nerve morphology (density, width, interconnections and tortuosity), neuropeptide concentration in the tears (SP and CGRP), and dry eye prior to surgery and at one day, one week, one month, three months and six months post-LASIK. The authors found an inverse relationship between re-innervation post-LASIK and dry eye symptoms, confirming that post-LASIK dry eye is a neuropathic disease. This is the first study to demonstrate an association between tear SP and post-LASIK re-innervation, suggesting that strategies for manipulating neuropeptide concentration to improve re-innervation may improve ocular comfort post-LASIK.

Surgical technique

Some improvements in surgical technique can decrease the incidence and severity of dry eye as well: these are smaller flaps, thinner flaps and hinge locations that spare more corneal nerves. A recent study of 1,800 subjects at 20 sites found that, compared with contact lens wear, current LASIK technology improved the ease of night driving, did not significantly increase dry eye symptoms, and resulted in higher levels of satisfaction at one, two and three years follow-up.³

Femto’s role

A recent publication supports the notion that, with new technologies, the low incidence of clinically significant postoperative dry eye may drop even lower. In Shen et al’s 2016 review of 12 randomized controlled trials with 1,076 eyes comparing femtosecond LASIK and SMILE, the authors found that both techniques are safe, effective and predictable surgical options for treating myopia. However, dry eye symptoms and loss of corneal sensitivity may occur less frequently after SMILE than after FS-LASIK.⁴

In a 2015 Xia et al. comparative study of 240 eyes with femtosecond vs. mechanically created LASIK flaps, both methods were determined to be safe and effective in correcting myopia, with no statistically significant differences in UCVA and BCVA during six months of follow-up.⁵ The refractive results remained stable after one month postoperative for both groups. The authors concluded that the femtosecond laser may have advantages over the microkeratome in the flap thickness predictability, fewer induced HOAs, better contrast sensitivity function and longer TBUT.

In the 2016 Chen and Manche review of the clinical evidence in the peer-reviewed literature, they found that femtosecond lasers create LASIK flaps with better accuracy, uniformity and predictability than mechanical microkeratomes.⁶ Newer higher-frequency femtosecond platforms elicit less inflammation, producing better visual outcomes. SMILE achieved similar safety, efficacy and predictability as LASIK with greater preservation of corneal nerves and biomechanical strength.

The authors concluded that femtosecond and excimer laser technologies improved the safety and efficacy of refractive procedures and led to the development of promising new treatment modalities, such as SMILE and wavefront-guided and topography-guided ablation.

Patient education

We have also learned the importance of giving patients reliable, balanced, understandable preoperative information, so that they know what to expect. This information should cover dry eye and its potential impact on outcomes. A list of available websites are on page 20.

There is now awareness that the LASIK speculum can stretch the lids, creating a temporary lagophthalmos, which results in a temporary exposure keratitis. This is often mistaken for, and also often coexists, with dry eye; it is diagnosed with fluorescein as a horizontal band of inferior corneal staining. In my experience, this temporary exposure keratitis is more likely to occur in patients over age 40, whose lids have more laxity to begin with.

At any rate, this condition is easily treated with just a few weeks of night-time gels or ointments.

It’s been 28 years since I performed the first PRK, the precursor of LASIK. We soon realized the relationship between a healthy tear film and excellent clinical outcomes. As American lifestyles changed — computer use, increased use of oral medications, and so on — we saw that ocular surface disease was on the rise. The development of modern refractive surgery was a strong impetus for industry to develop better diagnostic and therapeutic technologies to treat ocular surface disease. OM

REFERENCES

Patient satisfaction

Large-scale studies show patients are happy with the results.

By Greg Parkhurst, MD

Recently, famed TV host Dan Rather made news rather than reporting it. In a social media post, Mr. Rather described an extreme moment of somnolence. In his desire to get to bed quickly, he placed his contact lenses in a cup of tap water instead of properly storing them in the cleaning solution. Much to his chagrin, let alone his wife’s, he woke up in the morning prepared to insert his contacts only to realize that she, apparently thirsty in the middle of the night, gulped down the water along with both lenses. This set off a firestorm of reactions on social media that included other horror stories of the dangers of storing contacts in tap water, which can lead to devastating complications like acanthamoeba infections, scarring and even the potential need for corneal transplants.

What does Dan Rather’s much discussed contact lens story have to do with predicted growth of modern LASIK and refractive surgery? We need to consider solutions to our patients’ problems (myopia, astigmatism, hyperopia) in the aggregate and weigh them relative to each other. To expand their growth, refractive surgical procedures like LASIK should not be studied in a vacuum, but rather in comparison to other forms of refractive correction.

Recent studies (discussed below) along with some physician surveys indicate that refractive surgery is likely to experience a resurgence in growth. For most people, refractive surgery is a more effective solution for those who prioritize occupational fitness, safety, performance and even beauty. Due to these facts, many practices are experiencing double-digit increases in LASIK this year (See chart, page 92). There are several obvious reasons why this is the case.

Modern technology

More doctors are getting excited about focusing on refractive surgery again, in part due to numerous peer-reviewed publications on the safety and efficacy of modern LASIK. The research is effectively debunking some myths regarding the frequency of complications and side effects from older treatment modalities.

Current ASCRS President Kerry Solomon, MD, recently published his “Modern Laser in Situ Keratomileusis Outcomes” which is an update of the “LASIK World Literature Review: Quality of Life and Patient Satisfaction,” published in 2009. Dr. Solomon analyzed the impact of advanced treatment profiles in LASIK, such as use of a femtosecond laser and wavefront ablation profiles. This analysis evaluated nearly 4,500 clinical study papers on modern LASIK for relevancy and authority. The final data set included 97 high-quality studies that together represented over 67,000 procedures. In this analysis, 99.5% of patients achieved at least 20/40 vision, and 90.8% achieved 20/20 vision. From a safety perspective, fewer than 1% of patients lost two or more lines of BCVA.

Patient satisfaction

A prospective, multi-center study published in August in Ophthalmology by Price et al looked at 1,800 patients over a three-year period who stayed in contacts versus those who graduated to LASIK, comparing risks, benefits and levels of satisfaction with vision. This landmark study showed that contact-lens wear appears to be significantly more risky than LASIK when performed with modern technology on good candidates. This study formally compared these two common methods of refractive correction, which hadn’t been done on this scale in the past. Patients in the contact lens group had more abrasions, infections, complaints of dry eye, and worsening night vision/glare compared to those patients who went on to have LASIK. Furthermore, people who had LASIK surgery, compared to those who kept their contacts, were more satisfied with their vision on every metric at one, two and three years out.

An FDA-directed study, designed as a test instrument, of 574 subjects (262 active-duty military personnel, 312 civilians from five investigational sites) looked at a patient’s quality of life after LASIK. This study (in two phases), known as PROWL, showed overall satisfaction rates after modern LASIK of more than 96%. Also, visual symptoms, such as glare, starbursts, ghosting and halos, decreased on average. More than twice the number of patients reported their preoperative visual symptoms were gone at three months than those who reported an increase in symptoms at three months.

Reaching Millennials

Finally, the economics of modern refractive surgery are compelling for patients. Old barriers to entry included Baby Boomers’ and Gen Xs’ perception that refractive surgery was only available as a luxury item, primarily because it has historically been a single up-front cost. However, modern financing models have provided patients the opportunity to spread the cost of refractive surgery over a few years on a monthly basis, highlighting how much money is saved by treating their refractive error permanently.

Millennials are the patient demographic that will likely benefit most by refractive surgery, because of their age, and the years ahead of them. This generation, with its in-born trust of modern technology, likes to save money.

This graph summarizes the trends in refractive surgery volumes comparing small-volume refractive surgery practices to medium and large ones, which were significant (P < 0.001). Of 139 practices that consistently reported 100 eyes or more per year into the SurgiVision DataLink Alcon Edition for 2014 and 2015, 29% had lower volume in 2015 of 10% or more compared to 2014; volume in 45% were within ± 10% of 2014 and 33% grew by more than 10%. Of the practices that reported 500 or more cases/year, 63% showed positive growth from 2014 to 2015. Median growth in this group was 5%. So large/busy refractive surgery practices seem to be doing better than smaller ones.
[source: August 2016 private correspondence with Guy Kezirian, MD, FACS, SurgiVision Consultants, Inc.]

Millennials have a strong appreciation for authenticity. I am a successful laser vision-correction patient of more than 13 years myself. My colleagues and I at the Refractive Surgery Alliance published last September in the Journal of Cataract and Refractive Surgery survey results showing more than 90% of 232 refractive surgeons recommended refractive procedures for their family members. Of the 161 surgeons with treatable errors, 62.6% reported having an LVC procedure. The study says the prevalence of errors is higher among refractive surgeons than the public.

Conclusion

Peer-reviewed publications show LASIK to be one of the safest and most effective elective procedures available for those patients struggling with the limitations they might face in occupational fitness, wellness and opportunity.

Practices that have at the ready updated information regarding the real risk/benefit analysis of refractive surgery will be in the position to serve the growing number of patients seeking these life-enhancing procedures and services. OM

About the Authors
	Marguerite McDonald, MD, is a cornea-refractive surgeon, Ophthalmic Consultants of Long Island, Lynbrook, N.Y.; clinical professor, NYU Langone Medical Center, N.Y.; adjunct clinical professor, Tulane University, New Orleans. margueritemcdmd@aol.com.
	Greg Parkhurst, MD is the physician-CEO at Parkhurst-NuVision, a large ophthalmic-optometric integrated eyecare delivery system in San Antonio, TX. He is the sitting president of the Refractive Surgery Alliance, and he has served as principal investigator for several refractive surgery technologies and techniques.