Consistent positive trends in refractive surgery revamp motivation to innovation
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From the start of the pandemic in March 2020, laser vision correction procedure volume grew steadily, topping 833,000 in 2021.
This number of procedures, the highest since 2015, marked an increase of 32% over the previous year, according to data recorded by the Refractive Surgery Council.
Source: George O. Waring IV, MD, FACS
“We saw a boost of the demand when we thought we would see a drop of it. The numbers did not near the peak of the historic refractive market, but certainly a steady increase,” OSN Presbyopia Section Editor George O. Waring IV, MD, FACS, said.
This unexpected surge in volume was probably multifactorial. On one hand, mask wearing made it difficult to wear glasses because it fogged up the lenses, and by redirecting breath to the eyes, it caused and exacerbated dry eye symptoms in contact lens wearers.
“On the other hand, people had the opportunity to stop and reframe what was important in their lives. I think many started to understand the value over a lifetime of vision correction and the relative risks and benefits of vision correction vs. corrective aids such as spectacles and contact lenses,” Waring said.
Money saved on traveling and other leisure activities could then be invested in a refractive procedure.
In the first quarter of 2022, procedure volume increased by a further 5.3% and has since then remained fairly stable, OSN Refractive Surgery Section Editor John P. Berdahl, MD, said.
“It seems like procedure volumes have leveled out since that time. With the economic uncertainty rising across the globe, it will be interesting to see if there’s a decline or if patients are still willing to spend their money on things that improve quality of life as dramatically as refractive surgery,” he said.
Patient populations
There are basically two patient populations that present for refractive surgery screening, according to OSN Technology Board Member Karolinne M. Rocha, MD, PhD. One is young patients, active people who are seeking independence from spectacles and contact lenses for daily activities. Quite often they are experiencing issues with dry eye, and some have had episodes of infectious keratitis.
“The second group is the presbyopic patients who previously had good vision and now have issues with reading and come in looking for solutions,” she said.
Vision correction is not one size fits all: Every person and every stage of life have different needs that can be met by one or the other of the available procedures.
“We practice on a philosophy called ‘vision for a lifetime.’ A patient who has reached the first stage of ocular maturity, at age 18, typically presents for a laser refractive procedure or an implantable contact lens. At the second stage of ocular maturity, when the internal focusing lens loses its function with the onset of presbyopia, or stage 1 dysfunctional lens syndrome, people may present for refractive lens exchange, and then we get to the third stage of ocular maturity, and that’s a cataract. At every stage of life, we have a solution,” Waring said.
Advanced LASIK technology
LASIK is still the dominant player in the U.S., accounting for more than 70% of refractive procedures, and it is now most commonly femtosecond assisted and wavefront guided.
“In our center, we perform 100% femtosecond LASIK flaps. With the femtosecond laser, we obtain a planar-shaped flap vs. the meniscus-shaped flap that we see with mechanical microkeratomes. So, that’s why we shifted to femto since it has been available,” Rocha said.
Conventional LASIK ablation used to generate spherical aberration and, when decentered, could generate coma or secondary astigmatism, but new modalities, such as wavefront-guided, wavefront-optimized and topography-guided ablations, have overcome these problems.
“The choice between one or the other of these new modalities really depends on the laser platform,” Rocha said. “The iDESIGN Refractive Studio (Johnson & Johnson Vision) performs outstanding wavefront-guided ablations, while the WaveLight platform (Alcon) yields excellent results with topography-guided and wavefront-optimized LASIK. The latter is still very popular because it is all based on the patient’s manifest refraction and is very easy. Another option is topo-guided, specifically with the WaveLight here in the United States. Now you can use artificial intelligence to help calculate and plan the ablation profiles. And these patients are achieving vision even better than 20/20. We are definitely seeing more 20/15 with some of these special modalities.”
Lenticule extraction
Lenticule extraction, however, is gaining popularity. OSN Technology Board Member Kathryn M. Hatch, MD, performs SMILE (Carl Zeiss Meditec) more often than LASIK in her practice and offers it as first choice to patients who are candidates for the procedure.
“What I like about SMILE is the comfort and speed of the laser. The patients also like it because they have no restrictions after the procedure, as there are no concerns about potential flap issues. In addition, since less corneal nerves are transected, SMILE leads to less dry eye than LASIK, and healing is faster,” she said.
Hatch feels that SMILE has elevated the refractive experience of her practice because she is now able to offer a range of procedures, and patients like to have choices.
“That was a big reason for me to incorporate it into my practice. The Boston area is very competitive, and people have a wide choice of centers that offer refractive surgery. Offering the full spectrum of procedures allows us to stand out in the area,” she said.
Hyperopic SMILE is not yet approved by the FDA, but research shows promise, and Hatch is looking forward to this new opportunity. For now, she treats hyperopia with LASIK, but she stays cautiously below the 6 D that is currently approved.
“For hyperopia, mixed astigmatism, very low myopia and high astigmatism, I do LASIK. SMILE treats up to 3 D of astigmatism while LASIK can treat up to 6 D. Overall, we have much wider indications for LASIK than SMILE,” she said.
She believes that one of the barriers to the implementation of SMILE is the learning curve. Because surgeons have such great results with LASIK, they may not be motivated to learn a new procedure and invest in a new laser.
“These factors have really delayed the implementation of lenticule extraction in the U.S. But I do think the technology is here to stay, and I think it is the most innovative technology invented in our space since LASIK. Further fine-tuning will allow a potentially even more seamless procedure, and this will make SMILE move forward in a more rapid way,” Hatch said.
Refractive options for hyperopia
Hyperopic laser correction occurs with good frequency in the United States, according to Berdahl, but it is less common than myopia and myopic astigmatism correction because myopia is more common and because younger patients can accommodate through their hyperopia until later in life.
“However, when patients present with hyperopia and have started to lose accommodation, usually over age 44, refractive lens exchange becomes a viable option. For many surgeons, like me, it is definitely the preferred option,” he said.
LASIK is effective for the treatment of hyperopia, and all laser platforms are approved for the treatment of hyperopia and hyperopic astigmatism in the United States, Waring said.
“However, what we observe with the larger hyperopic correction is that often patients regress earlier and may not be candidates for a hyperopic enhancement. In this case, we have to move to an earlier lens-based intervention anyway. In addition, once we have created a large hyperopic ablation, we may limit our opportunities for certain lens choices in the future. Often these patients are latent hyperopes who actually express more hyperopia than they may be refracting internally, in which case a lens-based solution is more appropriate. So, we’ve really seen a trend, and I predict this trend will continue toward lens-based procedures for higher degrees of hyperopia. Lastly, these patients are at risk for chronic or subclinical or subacute angle closure, of which refractive lens exchange is the definitive fix,” he said.
Hyperopic laser procedures are an option for younger patients. However, hyperopic ablations usually create a hyperprolate cornea with increased negative spherical aberration, which can limit some IOL options in the future, Rocha said.
“In older patients, it might be worth waiting a few years until they start experiencing some age-related changes in the lens and then go for a lens-based procedure with advanced-technology IOLs, either diffractive or newer-generation monofocals with modified monovision,” she said.
PRK an important tool
Statistically, PRK is a small portion of the overall number of laser vision correction procedures in the U.S. However, it is still the preferred choice of some surgeons and an important tool in the armamentarium of all refractive surgeons.
“It is an important part of what we do in our practice. It is typically used for patients who are not good candidates for LASIK primarily because of corneal thickness,” Berdahl said.
“Patients with thin corneas or high prescriptions and those with a little abnormal topography are better treated with PRK than LASIK or SMILE. And I do see a fair number of irregular corneas too, and those are not candidates for LASIK,” Hatch said. “If someone has frank keratoconus, topo-guided PRK can be offered in select patients as an off-label procedure in conjunction with cross-linking. PRK can be offered as an enhancement in certain patients, but due to the longer recovery with PRK, I typically offer the other alternative options when possible.”
Waring added that PRK is an important option for patients who regularly engage in sport activities such as boxing.
“The professional commissioner for U.S. boxing reached out to me a number of years ago to ask my opinion on allowing PRK or LASIK in professional boxing, and we recommended PRK. For other contact sports that are high impact to the face, we might recommend PRK as well. However, LASIK has been studied in the military and is considered safe,” he said.
The recent advent of the EVO ICL (STAAR Surgical) has opened up a new opportunity for patients who are not ideally suited for LASIK.
“With higher corrections or other comorbidities that preclude LASIK, we have moved toward the ICL instead of PRK,” Waring said.
Dealing with presbyopes
PresbyLASIK is not yet FDA approved for use in the U.S., and the current laser techniques used for presbyopia are mainly limited to monovision and mini-monovision.
“Mini-monovision laser vision correction can be considered as a workaround for presbyopia. We are not treating the issue at the source, but instead we are just leaving people a little bit nearsighted in the nondominant eye so that they don’t need readers for everything,” Hatch said.
However, as the patient gets older, mini-monovision is usually no longer sufficient for reading without glasses. True monovision has a more powerful effect, but not everyone can tolerate it.
“Once patients get to a certain age, I look very closely at their natural lens, and if they want the full range of vision, I actually address their presbyopia through their natural lens, which is the root of the problem. These are patients who are typically at least in their mid-50s,” she said.
Looking at the lens and having a conversation with the patient are important to set realistic expectations and avoid disappointment.
“Quite often, patients who do laser vision correction in their 50s, even though they say they are fine wearing reading glasses, when it comes right down to it after the procedure, they can be quite disappointed,” Hatch said.
Laser vision correction should always be planned carefully and discussed thoroughly in view of the changes that occur in the eye later in life.
“We are doing patients a disservice if we treat, for example, very high myopia or hyperopia in an older patient. We must tell them frankly that if they need cataract surgery after 5 or 10 years, they may not be candidates for certain implant technologies because they have had that treatment on the cornea. We should make sure we counsel people, especially older people, about the implications of lens changes and cataract formation and implant options,” she said.
One particular use of laser for the aging lens, aimed at treating the sclera rather than the cornea, is laser scleral microporation (Ace Vision Group).
“It is an interesting procedure because you are not changing the shape of the cornea nor performing any invasive intraocular surgery. The laser, which is an Er:YAG laser, is applied in the sclera to change its biomechanical properties and allow for the ciliary muscle to contract. We look forward to hearing more about the clinical trials,” Rocha said.
Waring also sees laser scleral microporation as a promising new way to restore some accommodation. Currently, he offers blended vision for presbyopia in some cases, but by far the most common procedure for presbyopia in his practice is custom lens replacement with a femtosecond laser.
“We feel that going to the source of the problem usually makes the most sense,” he said.
Innovations on the horizon
Every company in the refractive surgery landscape is currently developing new platforms, both for excimer laser and femtosecond laser technology.
“We are very excited about the innovation in this space where, for a period of time, innovation was at a standstill. The industry as a whole is embracing lenticule technology. There is also a move toward machines with a much smaller footprint, and that’s really important as we see the possibility of more practices moving to in-office surgery,” Waring said.
New-generation multipurpose machines offer integrated advanced diagnostics, planning and treatment modules.
“We are going to perform more image-guided treatments that aim to have greater potential to increase precision and accuracy and decrease the potential for human error. We have just taken part in the FDA trial on the treatment of myopia and myopic astigmatism with the Bausch + Lomb Teneo laser, a laser with a very exciting small footprint. This also holds great promise,” Waring said.
In the pipeline, there are new diagnostic systems with epithelial mapping capabilities and advanced centration techniques with integrated chord mu measures.
“These are all very exciting iterations for both lenticule and excimer treatments, as well as potentially for hybrid treatments that may look at wavefront-optimized, topography-guided, wavefront-guided and ray-tracing technologies,” he said.
Some of the old techniques have fallen out of favor.
“The standard laser ablations have fallen out of favor over time. In addition to that, we are seeing fewer mechanical microkeratomes being used,” Berdahl said.
Conductive keratoplasty seems to be a dying procedure, and corneal inlays and onlays are used seldomly in a narrow patient population of plano presbyopes, Rocha said.
“Allogenic inlays, however, are in early phase development. They seem to be more biocompatible and are showing positive early results,” Waring said.
Looking into the future, the concept of refractive index shaping, applied to the lens and corneal tissue, might be the next step forward in refractive surgery.
“It is a non-ablative procedure in which femtosecond laser pulses tightly focused into the tissue induce selective refractive index changes,” Waring said.
- References:
- Ang M, et al. Eye (Lond). 2021;doi:10.1038/s41433-020-1096-5.
- Bickford M, et al. Curr Ophthalmol Rep. 2021;doi:10.1007/s40135-021-00280-2.
- Cummings AB, et al. Eur J Ophthalmol. 2021;doi:10.1177/11206721211018641.
- Dick HB, et al. J Refract Surg. 2022;doi:10.3928/1081597X-20220817-01.
- Frings A, et al. Acta Ophthalmol. 2018;doi:10.1111/aos.13486.
- Mercer RN, et al. J Refract Surg. 2021;doi:10.3928/1081597X-20210408-06.
- Moshirfar M, et al. Curr Opin Ophthalmol. 2019;doi:10.1097/ICU.0000000000000580.
- Rocha KM, et al. J Refract Surg. 2021;doi:10.3928/1081597X-20210408-01.
- RSC reports 32% YTD increase in LVC procedure volume over 2020. https://americanrefractivesurgerycouncil.org/press-room/refractive-surgery-council-reports-32-ytd-increase-in-laser-vision-correction-procedure-volume-over-2020/. Published Jan. 31, 2022. Accessed Nov. 15, 2022.
- Shah R. Asia Pac J Ophthalmol (Phila). 2019;doi:10.1097/01.APO.0000580132.98159.fa.
- Sia RK, et al. Mil Med. 2021;doi:10.1093/milmed/usaa507.
- Stonecipher K, et al. Curr Opin Ophthalmol. 2018;doi:10.1097/ICU.0000000000000495.
- For more information:
- John P. Berdahl, MD, can be reached at Vance Thompson Vision, 3101 W. 57th St., Sioux Falls, SD 57108; email: john.berdahl@vancethompsonvision.com.
- Kathryn M. Hatch, MD, can be reached at Mass Eye & Ear, 1601 Trapelo Road, Suite 184, Waltham, MA 02421; email: kathryn_hatch@meei.harvard.edu.
- Karolinne M. Rocha, MD, PhD, can be reached at Storm Eye Institute, Medical University of South Carolina, 167 Ashley Ave., Charleston, SC 29425; email: karolinnemaia@gmail.com.
- George O. Waring IV, MD, FACS, can be reached at Waring Vision Institute, 735 Johnnie Dodds Blvd., Suite 101, Mt. Pleasant, SC 29464; email: gwaring@waringvision.com.
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