The annual Global Specialty Lens Symposium (GSLS), presented by Contact Lens Spectrum and held Jan. 25 to 28, 2018 in Las Vegas, once again demonstrated why it is one of the premier specialty contact lens meetings in the world. With a total of 96 available courses, the 674 attendees representing 35 countries could customize their interests to areas in which they desired more clinical knowledge. The educational program was developed by the GSLS Education Planning Committee, chaired by Craig Norman and including Jason J. Nichols, OD, MPH, PhD; Edward Bennett, OD, MSEd; Eef van der Worp, BOptom, PhD; and Patrick Caroline. Much of the emphasis was on topics related to scleral lenses and myopia control, but there was also information presented on multifocals, keratoconus, dry eye management, specialty lens coding and billing, and contact lens materials and coatings, to name a few. Numerous industry-sponsored sessions allowed eyecare practitioners (ECPs) to learn about indications for, and how to fit and troubleshoot, new lens designs.

The Pre-Conference program, which traditionally takes place on the Thursday morning of the opening day, was again very popular. Four courses each were presented in the following tracks: GPLI, co-hosted by the GP Lens Institute (GPLI); Myopia, co-hosted by the American Academy of Orthokeratology and Myopia Control (AAOMC); Practice Management, co-hosted by Optometric Management; Keratoconus, co-hosted by the International Keratoconus Academy of Eye Care Professionals; and Scleral Lenses, co-hosted by the Scleral Lens Education Society (SLS).

In addition, the much-anticipated premier of The Contact Lens Museum occurred in the 2018 GSLS Exhibit Hall. The brainchild of Patrick Caroline, in collaboration with scleral lens pioneer Donald Ezekiel, Dip Opt(WA), and Craig Norman, many of the early scleral contact lenses as well as contact lens equipment, instrumentation, education materials, and other items were on display (Figure 1).

The exhibit hall also once again featured live demonstrations of specialty lens fabrication by Contact Lens Manufacturers Association member labs.

GSLS AWARDS

A wonderful annual tradition of this meeting is the GSLS Award of Excellence. In 2018, the recipients were four individuals who have iconic status in the area of myopia research. Those honored were Drs. Thomas Aller, Pauline Cho, Earl L. Smith III, and Jeffrey J. Walline (Figure 2).

Another annual highlight are the awards for excellence in scientific posters (See sidebar on p. 24). Six individuals were honored for excellence in the clinical and research categories from the record 118 scientific posters exhibited.

It is also important to note that the SLS presented two awards for excellence in scleral posters. These were awarded to Alyssa Perlman-Hensen, OD, Cornea and Contact Lens resident at the New England College of Optometry, and Taylor Dahms, fourth-year student at the University of Missouri-St. Louis College of Optometry and American Optometric Student Association National Liaison to the Contact Lens & Cornea Section of the American Optometric Association.

There were also three award recipients in the annual GSLS Photo Contest. Photos this year were selected from among submissions for the two categories of Cornea, Conjunctiva, Lids and Contact Lens. The award-winning photos, in no particular order, are featured on the cover of this issue.

THE HISTORY OF CONTACT LENSES

Patrick Caroline took attendees on a fascinating walk down memory lane with his discussion on “The Evolution of Contact Lenses,” explaining that we need to understand where we came from, and then maybe we can understand where we’re going with new contact lens modalities. He began by debunking the popular idea that Leonardo da Vinci was the first person to envision the concept of a contact lens. Pat Caroline stated that da Vinci’s illustration of a person with his head submerged in a bowl of water from his 1508 Codex of the Eye was not a contact lens—he explained that da Vinci’s drawings are actually a schematic of the eye to explain the mechanism of image formation on the retina. It was in the 1800s that British mathematician and astronomer Sir John Herschel first described how an optical device could be designed with a posterior surface—“an exact facsimile of the cornea”—and an anterior surface designed to correct the refractive error.

He then went on to describe how contact lenses, their materials, care systems, and the processes and equipment to both evaluate and manufacture them have evolved over time, from the first blown-glass scleral shells and ground glass scleral lenses of the 1880s up to today’s modern soft and GP lenses. Some fun/interesting highlights included a video of scleral lens application and removal from the 1930s (Figure 3) that would still be applicable today; scleral lens care instructions that included rinsing the lenses with cold water, licking the surfaces, and “Saliva is good for wetting the lenses, but not immediately after eating, unless the teeth are brushed first”; and the revelation that Kevin Touhy’s wife played a critical role in the development of corneal rigid lenses by asking their lab technician to cut away material from her tight-fitting scleral lens while her husband was away.

MYOPIA CONTROL IN 2018

The worldwide interest in the effects of myopia and the methods by which it can potentially be controlled was evident not only from the recipients of the GSLS Awards of Excellence, but also in the education program itself.

In a two-hour general session, renowned myopia researcher Dr. Walline reviewed studies pertaining to peripheral plus soft lenses versus overnight orthokeratology (ortho-k) in myopia control. In reviewing eight studies published between 2011 and 2016 pertaining to soft lenses for myopia control, he reported an average of 36.4% slowing in refractive error and 37.9% reduction in progression of axial length.^1-8 As Dr. Walline had previously reported, a reduction in myopia by a minimum of 50% is clinically meaningful (i.e., a 1.00D myopic child at age 8 progressing 0.50D per year will be a –5.00D myope at age 16 with no intervention or a –3.00D myope with a 50% reduction myopia control method).⁹

However, recently a few new soft lens designs show much promise in exhibiting a greater effect on myopia progression. One that is currently available in the United States uses an extended depth of focus design. A retrospective case series with 32 patients wearing this lens design evaluated over a variable time period (six to 25 months) reported a reduction in the annualized rate of myopia progression from –0.85D per year to –0.04D per year, representing a reduction of more than 95%.¹¹ One of the authors of this paper, Brett O’Connor, OD, also presented a free paper on a retrospective series of 27 patients, followed up for anywhere from six to 18 months (average = 7.6 months). He reported that these patients went from increasing –0.80D per year pre-fit to +0.02D post-fit or a 102% slowing of progression.

Another soft multifocal design is not yet available in the United States, but Dr. Walline discussed data on the lens that had been released by the manufacturer at the British Contact Lens Association meeting in 2017. These data showed three-year findings from a clinical trial assessing the dual-focus myopia control one-day soft lens in reducing the rate of progression of juvenile-onset myopia. The prospective, multi-center, double-masked, randomized multi-year study enrolled 144 myopic children aged 8 to 12 years from Singapore, Canada, England, and Portugal. Three-year findings indicated that use of this contact lens, which has alternating visual correction and treatment zones, was effective in slowing myopia progression by 59% as measured by mean cycloplegic spherical equivalent (SE) and 52% as measured by mean axial elongation of the eye when compared to the children in the control group wearing a single-vision one-day contact lenses.¹⁰ Although these studies are retrospective, lack a control group, and have a limited and variable time period for evaluation, they do demonstrate the potential of soft lenses as devices for myopia control.

Dr. Walline also reported on studies pertaining to overnight ortho-k, indicating that the average effect on axial length was greater than with peripheral plus soft lenses—albeit not much greater—at 43%.^6,12-20 In addition, he reviewed studies on low-dose (0.01%) atropine and its effect of reducing myopia. Based on these studies, the effect, even in a low-dose format, was greater than with contact lenses.^21-23 In addition, when studied over a five-year period, 0.01% atropine was more effective in slowing myopia with less visual side effects compared to higher doses of atropine.²³ The unknowns at this time are which method (atropine, overnight ortho-k, or soft lenses) will work best for a given individual and whether a combination of these treatments will result in greater myopia control.

In the pre-conference myopia track, attendees learned about the effect of the different methods of controlling myopia—all off-label—as well as how to implement them into clinical practice and, in the case of contact lens modalities, how to fit and troubleshoot these designs. Drs. Caroline Cauchi and Matthew Martin emphasized that overnight ortho-k is safe if the appropriate precautions are taken. In fact, ortho-k has no greater risk of microbial keratitis than overnight extended wear lenses do.^24,25 Their bottom line message was that ortho-k is very safe when performed by a well-trained practitioner following careful protocols. Drs. Cauchi and Martin also emphasized that a corneal topographer is essential when incorporating overnight ortho-k into the practice. Without topography assessment, it would essentially be impossible to know exactly what the lens is doing on the eye. Finally, they emphasized the need to have an informed consent signed by the patient. The benefits are three-fold: 1) legal purposes, 2) risk management, and 3) patient education.

Langis Michaud, OD, MSc, reviewed environmental factors in controlling myopia progression. He relayed that increased time outdoors is effective in preventing the onset of myopia as well as slowing the myopic shift in refractive error, but, paradoxically, it was not effective in slowing progression in eyes that were already myopic.²⁶ In addition, violet-light-transmitting contact lenses may be one of the most important outdoor environmental factors for myopia control because ultraviolet (UV) light in the range of 380nm to 400nm increases the expression of the gene EGR1, which is responsible for regulating axial elongation of the eye.²⁷

Dr. Michaud also, in a free paper, outlined his approach to determining which method(s) of myopia control to use for a given young person. He developed a formula that is accompanied by a clinical management nomogram, which includes overnight ortho-k, soft multifocal lenses, atropine, and environment. This formula is also available in a recent publication.²⁸

SCLERALS, SCLERALS, SCLERALS

As has been customary in recent years at the GSLS, at least 25% of the education presented pertained to scleral lenses. Muriel Schornack, OD, reported on the latest results of the Scleral Lenses in Current Ophthalmic Evaluation (SCOPE) survey. In particular, she focused on whether scleral lenses were having a significant impact with healthy patients. In the SCOPE II survey results, only 5% of the patients wearing scleral lenses exhibited uncomplicated refractive errors. The study authors concluded that the low percentage of scleral wearers who had healthy eyes was the result of numerous patient (i.e., handling, cost, and fitting process) and practitioner (i.e., learning curve for fitting, risk factors, chair time) barriers.

Many of the barriers for healthy-eyed patients were debunked by Daddi Fadel, DOptom. She made a convincing argument that scleral lens concerns such as difficulty in handling, harder to fit, greater expense, increased complications, and reduced comfort compared to soft lenses were either simply not true or were relative to other lens types. She has found that scleral lenses can be more stable and can offer optimal comfort and better vision to individuals who have astigmatism and presbyopia, who are active in sports, or who desire ortho-k.

Clark Chang, OD, reported on the importance of using an optical coherence tomographer (OCT) for evaluating scleral lens clearance from the central cornea. The mean difference is 102.66 microns (range 53 to 207 microns) when comparing the value found with an OCT versus that estimated with the slit lamp biomicroscope.²⁹

One of the burning questions that was answered at this year’s GSLS was: What are the results of a large scleral lens-wearing population? Adeline Bauer, OD, presented a free paper on the findings of 150 patients in one practice being fitted into scleral lenses over a 10-month period. The breakdown of patients included 1) keratoconus: 55.9%; 2) ocular surface disease: 11.3%; 3) post-laser-assisted in situ keratomileusis (LASIK): 7.3%; 4) scar: 7.3%; and 5) transplant: 5.3%. At the time of fitting, 39.7% were wearing spectacles, 23.1% were not wearing a correction, 21.9% were wearing scleral lenses, 12.6% were wearing corneal GP lenses, and 2.8% were wearing soft lenses. She reported that 11.7% decided not to order lenses (i.e., cost, no vision improvement), and 10 patients dropped out. Only one scleral lens design was used, and 41.3% ended up with the same sagittal depth design. The average number of lenses ordered per eye to achieve success was 1.70, and 26.5% of the lenses had a toric front-surface power. The most common changes after the initial lens order were the following:

1. Changes in peripheral or limbal curves to decrease fogging (23.4%)
2. Residual over-refraction incorporated (19.1%)
3. Vault increase or decrease (10.1%)
4. Changes in peripheral or limbal curves to loosen tight lenses (5.2%)
5. Changes to material to help lens wetting (2.7%)

Aberration-control scleral lens developments are also very promising. Matthew J. Kauffman, OD, part of the research team with Dr. Jason Marsack at the University of Houston College of Optometry, presented a free paper on the initial results of a wavefront-guided scleral lens compared to a conventional scleral lens design in individuals who have irregular corneas. He reported that wavefront-guided scleral lenses are no exception to other sclerals in that they tended to decenter inferior-temporal (an average of 0.4mm inferior and 0.45mm temporal). The wavefront optics resulted in improved logMAR visual acuity and reduced higher-order wavefront errors.

The impact of scleral lenses, in general, on higher-order aberrations in keratoconus patients was reported in a free paper by Dr. Sandrine Malaison-Tremblay. Wavefront aberrometry, with and without scleral lenses, was evaluated in 51 keratoconic eyes. The authors evaluated total high-order aberrations, coma, and trefoil. They found greater than or equal to 60% reduction for total higher-order aberrations in 29 eyes. In addition, they found that the more pronounced the aberrations, the better improvement was obtained with scleral lenses.

Greg DeNaeyer, OD, and Sheila Morrison, OD, reported on scleral shape as it relates to scleral lens fitting. They emphasized that most eyes are asymmetrical, and the anterior shape of the right and left eyes is often different enough to require a unique lens fit for each eye. Also, scleral shape is highly asymmetrical and often has toricity that is not in the same orientation and magnitude as the corneal toricity. Therefore, as future lens designs increase in diameter, imaging of the cornea and sclera could be helpful in creating lenses that take into consideration the asymmetry of the sclera.³⁰ They also mentioned some preliminary findings from The Scleral Shape Study Group (Drs. DeNaeyer, Morrison, Donald Sanders, van der Worp, Jason Jedlicka, and Michaud). Of 152 eyes of prospective scleral lens patients, 65.7% did not exhibit a spherical or toric-regular scleral surface pattern but instead exhibited asymmetry or periodicity different than 180˚; therefore, these eyes may benefit from custom-back-surface haptics.

There were several presentations on scleral lens troubleshooting, a topic that could be a separate article in itself. An excellent overview was provided by Drs. Pam Satjawatcharaphong and Dan Fuller; as with almost all of the courses, the entire presentation can be accessed online at www.gslsymposium.com under “Agenda.”

MULTIFOCAL UPDATE

The potential benefits of decentered optics with soft multifocal lenses were the focus of a free paper by Dr. Jedlicka and were also emphasized in a presentation by Matthew Lampa, OD. Dr. Jedlicka quoted the work of Dr. Lampa et al that soft multifocal lenses tend to decenter inferior-temporal, and even a small resulting angle lambda can account for 1.25mm of difference between the pupillary axis and the line of sight topographically.³¹ In a total of 180 eyes, he reported an average resulting decentration of optical axis relative to the anatomical center of the cornea of 0.115mm superior and 0.374mm nasal. This can result in induced astigmatism, the need for higher add powers, and the need for larger add zones. Decentered multifocal optics could help reduce or eliminate these problems.

Dr. Lampa cited work by himself and colleagues at Pacific University in which each subject was fit with a standard aspheric center-distance design and two designs with the center-distance zone offset nasally. They found that the Snellen acuity and subjective vision were decreased with increasing temporal decentration from the line-of-sight and that the subjects overwhelmingly preferred the decentered optics lenses for future wear.³²

Thomas G. Quinn, OD, MS, provided a comprehensive overview of multifocal lens designs and their applications. Front-surface aspheric GP designs are available from almost every GP laboratory and have the benefits of providing optimal vision compared to soft lenses because of the GP optics and the center-distance design. In addition, they can be fit empirically and are not prone to possible corneal topography changes that the higher-eccentricity back-surface aspheric designs can induce.

Newer hybrid contact lens options provide hyper-Dk materials and multiple add powers; he noted that these are a viable option for astigmatic patients who desire good initial comfort. Custom soft multifocals are becoming more popular as an increasing number of designs are being introduced, many in a latheable silicone hydrogel material. They can be successful for patients in need of non-standard lens parameters (i.e., high spherical refractive errors, high cylinder correction at any axis) and when standard designs result in reduced vision or a poor fitting relationship.

Dr. Quinn emphasized that it should be assumed that ≥ 0.75D of uncorrected or residual cylinder is too much. He also reported that the higher the amount of toric corrective power in the lens, the more that lens rotation will induce excessive cylinder.

PRACTICE MANAGEMENT

The GSLS always provides courses to help ECPs who want to either establish or grow a specialty contact lens practice. According to contact lens practice management expert Jason Miller, OD, MBA, it all begins with effectively communicating to every qualified candidate that contact lenses are an option. If they do not wish to proceed at that time, you have at least planted the seed.

Sarah Morgan BSc, MPhil, MCOptom­—who entertained the audience with her musical talents displayed in the original compositions “Presbyopia” and “Myopia”—also emphasized the need to be proactive with patients about contact lenses. She indicated that ECPs who proactively recommended contact lenses to all patients were able to fit a much higher percentage of patients into lenses compared to reactive ECPs, which translated into much greater revenue to the practice. She also recommended putting daily disposable lenses on spectacle lens patients’ eyes while they are making their frame selection—not for the purpose of trying contact lenses, but to help them see the frames on their face better; this can allow patients to experience the benefits of contact lenses in a low-pressure situation and may encourage future lens trials.

The GSLS also always features lectures on specialty lens billing and coding. This year, Stephanie Woo, OD, provided a very “common sense” presentation on this important subject. As a practitioner who became a partner in a multi-center private practice that did not emphasize specialty contact lenses, she had to start at the beginning and learn how to properly code and bill as she built a flourishing specialty lens practice. She commented that billing and coding is a leading source of frustration for practitioners. However, she also stated that specialty lenses can include standard soft lenses, custom soft lenses, and corneal GP lenses in addition to hybrid and scleral lenses. She explained that specialty lenses can be a profit source in the practice and that most vision insurances reimburse well for specialty lens fittings and devices.

CONTACT LENS DISCOMFORT AND DROPOUTS

Jason Nichols, OD, MPH, PhD; Lyndon Jones, PhD, FCOptom; and Philip B. Morgan, PhD, MCOptom, teamed up for the session “Where Have All the Lens Wearers Gone,” which started with an in-depth overview of lens-wearing trends, including the numbers of contact lens wearers in various markets and the number of lens wearers dropping out of various markets. In many of the major markets today, the numbers entering and exiting contact lens wear are about the same, suggesting some stagnation in growth.

However, there are several emerging markets that are showing significant growth in the number of new lens wearers to the market. Several forces were discussed in relation to their roles in market growth and/or stagnation. It is well documented that contact lens discomfort and dryness play a huge role in the long-term success of contact lens wearers, but it was also recognized that vision plays a large role as well. There is definitely expansion in some segments of the market, notably in scleral lenses and myopia control.

Because of the active involvement of ECPs in fitting specialty contact lenses in particular, it was noted that specialty lenses are a means to protect the integrity of the contact lens prescription. This is counter to the online initiative seen presently today, whereby several companies are offering contact lenses directly to patients that have not been examined or fitted in a contact lens.

WHAT’S NEW IN KERATOCONUS

Jan Bergmanson, OD, PhD, DSc, moderated the session “Keratoconus – Keeping Patients and Management Up to Date.” He noted that while keratoconus was first identified about 150 years ago, we still don’t know where it comes from or where it starts. What we do know is that keratoconus involves the entire cornea—all layers, and not just the cone. In addition, simple corneal thinning cannot explain the ectasia, something else must be happening biomechanically.

Dr. Bergmanson went on to describe work with which he is involved at the Texas Eye Research and Technology Center at the University of Houston indicating that the anterior limiting lamina (ALL) or Bowman’s layer is thinned or lost over large areas in keratoconic corneas, but the lamellar count is higher. For this reason, he proposes that lamellar splitting (Figure 4) results in the biomechanical weakening that causes ectasia, similar to a many-stranded rope becoming weak when the strands are unraveled.

Carina Coppen, MD, discussed corneal cross-linking, in particular what is currently evidence-based and what is not. She indicated that while many new indications and ways to perform the procedure have been developed, currently only the epi-off technique is proven to be effective through evidence-based research. Essentially, there are many new CXL-related acronyms emerging, but as yet not much evidence available.

S. Barry Eiden, OD, discussed new technologies that can help with earlier diagnosis of keratoconus. Some of these technologies are discussed in this month’s Research Review column on p. 12. An upcoming technology that is anticipated to receive FDA clearance within the next year combines an air puff and Scheimpflug video—the deformation and undulation of a keratoconic cornea is different compared to a normal cornea, as is how quickly the cornea recovers. Dr. Eiden said that this technology also combines with tomography data.

AND SO MUCH MORE

These highlights only scratch the surface of all of the great information presented at the GSLS meeting. In addition, there was a general session and several breakout sessions on prosthetic and cosmetic tinted lenses, including tinted lens options, indications, cases, and a discussion of how to market these lenses in university/hospital settings versus in private practice.

Tom Arnold, OD, whose contact lens photography expertise—notably in scleral lenses—is on display in specialty contact lens social media as well as in articles and scleral lens resources, spoke on the essentials of slit lamp photography. He included an overview of equipment, slit lamp and camera settings, lighting considerations, how to position and focus the camera to capture the perfect shot, and photo editing software.

Michael Ward, MMSc, discussed lens care/compliance issues and how to avoid complications and improve outcomes. He tackled the controversial topic of whether it is safe to use tap water to rinse GP lenses—in particular, whether there is a disconnect between the public health messaging regarding tap water use with contact lenses and the realities of caring for GP lenses.

Melanie Frogozo, OD, and Alexandra Williamson, OD, discussed GP contact lens applications in pediatric patients. They covered lens selection and design considerations, how to apply and remove GP corneal and scleral lenses on both cooperative and uncooperative children, and fit evaluation and follow up. They also presented a number of cases.

Jerome Legerton, OD, MS, MBA, discussed new technologies in specialty contact lenses, including for applications such as sensing, drug delivery, refractive error regulation (not just myopia control), photonics and molecular biology, presbyopia, low vision, wearable displays, and corneal wound healing.

These presentations and many others are worthwhile to view on the GSLS website. Mark your calendars to attend the next GSLS, which will take place from Jan. 24 to 27, 2019 at the Tropicana in Las Vegas. CLS

REFERENCES

1. Anstice NS, Phillips JR. Effect of dual-focus soft contact lens wear on axial myopia progression in children. Ophthalmology. 2011 Jun;118:1152-1161.
2. Sankaridurg P, Holden B, Smith E III, et al. Decrease in rate of myopia progression with a contact lens designed to reduce relative peripheral hyperopia: one-year results. Invest Ophthalmol Vis Sci. 2011 Dec;52:9362-9367.
3. Lam CS, Tang WC, Tse DY, Tang YY, To CH. Defocus Incorporated Soft Contact (DISC) lens slows myopia progression in Hong Kong Chinese schoolchildren: a 2-year randomised clinical trial. Br J Ophthalmol. 2014 Jan;98:40-45.
4. Walline JJ, Greiner KL, McVey ME, Jones-Jordan LA. Multifocal contact lens myopia control. Optom Vis Sci. 2013 Nov;90:1207-1214.
5. Fujikado T, Ninomiya S, Kobayashi T, Suzaki A, Nakada M, Nishida K. Effect of low-addition soft contact lenses with decentered optical design on myopia progression in children: a pilot study. Clin Ophthalmol. 2014 Sep 23;8:1947-1956.
6. Paune J, Morales H, Armengal J, Quevedo L, Faria-Ribeiro M, González Méijome JM. Myopia control with a novel peripheral gradient soft lens and orthokeratology: a 2-year clinical trial. Biomed Res Int. 2015;2015:507572.
7. Aller TA, Liu M, Wildsoet CF. Myopia control with bifocal contact lenses: A randomized clinical trial. Optom Vis Sci. 2016 Apr;93:344-352.
8. Cheng X, Xu J, Chehab K, Exford J, Brennan N. Soft contact lenses with positive spherical aberration for myopia control. Optom Vis Sci. 2016 Apr;93:353-366.
9. Walline JJ. Current and future developments in myopia control. Contact Lens Spectrum. 2012 Oct;27:34-38.
10. MiSight Brochure distributed by CooperVision at 2017 British Contact Lens Association meeting.
11. Cooper J, O’Connor B, Watanabe R, et al. Case series analysis of myopic progression control with a unique extended depth of focus multifocal contact lens. Eye Contact Lens. 2017 Oct 19. [E-pub ahead of print]
12. Hiraoka T, Kakita T, Okamoto F, Takahashi H, Oshika T. Long-term effect of overnight orthokeratology on axial length elongation in childhood myopia: a 5-year follow-up study. Invest Ophthalmol Vis Sci. 2012 Jun 22;53:3913-3919.
13. Cho P, Cheung SW. Retardation of myopia in orthokeratology (ROMIO) study: a 2-year randomized clinical trial. Invest Ophthalmol Vis Sci. 2012 Oct 11;53:7077-7085.
14. Santodomingo-Rubido J, Villa-Collar C, Gilmartin B, Gutiérrez-Ortega R. Myopia control with orthokeratology contact lenses in Spain: refractive and biometric changes. Invest Ophthalmol Vis Sci. 2012 Jul 31;53:5060-5065.
15. Charm J, Cho P. High myopia-partial reduction ortho-k: a 2-year randomized study. Optom Vis Sci. 2013 Jun;90:530-539.
16. Swarbrick HA, Alharbi A, Watt K, Lum E, Kang P. Myopia control during orthokeratology lens wear in children using a novel study design. Ophthalmology. 2015 Mar;122:620-630.
17. Chen C, Cheung SW, Cho P. Myopia control using toric orthokeratology (TO-SEE study). Invest Ophthalmol Vis Sci. 2013 Oct 3;54:6510-6517.
18. Kakita T, Hiraoka T, Oshika T. Influence of overnight orthokeratology on axial elongation in childhood myopia. Invest Ophthalmol Vis Sci. 2011 Apr 6;52:2170-2174.
19. Walline JJ, Jones LA, Sinnott LT. Corneal reshaping and myopia progression. Br J Ophthalmol. 2009 Sep;93:1181-1185.
20. Cho P, Cheung SW, Edwards M. The longitudinal orthokeratology research in children (LORIC) in Hong Kong: A pilot study on refractive changes and myopia control. Curr Eye Res. 2005 Jan;30:71-80.
21. Clark TY, Clark RA. Atropine 0.01% eyedrops significantly reduce the progression of childhood myopia. J Ocul Pharmacol Ther. 2015 Nov;31:541-545.
22. Loughman J, Flitcroft DI. The acceptability and visual impact of 0.01% atropine in a Caucasian population. Br J Ophthalmol. 2016 Nov;100:1525-1529.
23. Chia A, Lu QS, Tan D. Five-year clinical trial on atropine for the treatment of myopia 2: myopia control with atropine 0.01% eyedrops. Ophthalmology. 2016 Feb;123:391-399.
24. Bullimore MA, Sinnott LT, Jones-Jordan LA. The risk of microbial keratitis with overnight corneal reshaping lenses. Optom Vis Sci. 2013 Sep;90:937-944.
25. Liu YM, Xie P. The safety of orthokeratology–a systematic review. Eye Contact Lens. 2016 Jan;42:35-42.
26. Xiong S, Sankaridurg P, Naduvilath T, et al. Time spent in outdoor activities in relation to myopia prevention and control: a meta-analysis and systematic review. Acta Ophthalmol. 2017 Sep;95:551-566.
27. Torii H, Kurihara T, Seko Y, et al. Violet light exposure can be a preventive strategy against myopia progression. EBioMedicine. 2017 Feb;15:210-219.
28. Michaud L, Simard P. Myopia control with ortho-k. Contact Lens Spectrum. 2017 Sep;32:20-26.
29. Brujic M. Estimating scleral lens clearance and comparing it to OCT measured clearance. Poster presented at the Global Specialty Lens Symposium, January 2016, Las Vegas.
30. Kinoshita B, Morrison S, Caroline P, et al. Corneal toricity and scleral asymmetry...are they related? Poster presented at the Global Specialty Lens Symposium, January 2016, Las Vegas.
31. Lampa M, So K, Caroline P, et al. Multifocal lens centration with the aid of corneal topography. Poster presented at the Global Specialty Lens Symposium, January 2012, Las Vegas.
32. Zhang F, Caroline P, Lampa M, et al. Visual effects of centered and decentered multifocal optics. Poster presented at the Global Specialty Lens Symposium, January 2016, Las Vegas.