THE 2023 GLOBAL SPECIALTY LENS SYMPOSIUM (GSLS), presented by Contact Lens Spectrum (CLS), was held Jan. 18-21 at Horseshoe Las Vegas, formerly Bally’s. This year’s program again covered the most current clinical education pertaining to timely topics in specialty lens education. Attendance nearly returned to pre-pandemic levels with well over 1,000 people in attendance.

This year’s continuing education (CE) program included four workshops (with one presented in Spanish), nine general sessions, and 17 courses with an emphasis on myopia management, scleral lenses, GP lenses, dry eye, contact lens multifocals, and OD/MD collaboration. In addition, there were 125 scientific posters, five free papers highlighting cutting-edge research, and more than 40 sponsored presentations, allowing attendees to learn about new specialty lens designs, technologies, and services being offered by the industry.

The 2023 GSLS Education Committee is comprised of Jason J. Nichols, OD, MPH, PhD (chair); Karen DeLoss, OD (vice chair); Patrick Caroline; Eef van der Worp, BOptom, PhD; and Ashley Wallace-Tucker, OD.

Here, we offer some highlights from seven of the nine general sessions. For information from general session #4, see “These Ain’t Ben Franklin’s Bifocals” on page 32. For information about all posters, including those presented in the Rapid-Fire Poster Session (general session #5), visit bit.ly/GSLS23posters .

GENERAL SESSION #1: WORST CASE SCENARIO

The opening session, “Worst Case Scenarios,” was moderated by Deborah Jacobs, MD, MS, with panelists Derek Louie, MSc, OD; Christine Sindt, OD; Karen Carrasquillo, OD, PhD; and Carina Koppen, MD, PhD. These cases were often managed by some form of scleral (typically custom) lenses.

Several cases were presented in which penetrating keratoplasy (PKP) was performed and the patient ultimately was diagnosed with glaucoma. Several factors included the use of corticosteroids to reduce inflammation, and a PKP performed in a young person in which intraocular pressure (IOP) could not be performed or was not performed because of the low risk of glaucoma. The bottom line was to always look out for glaucoma on postsurgical cases.

Additional cases were presented that had patients who had ptosis or related lid deficiencies. It was found that fitting a scleral lens will help lift the lid up in a patient who has myasthenia gravis and keratoconus. Likewise, a young girl with trisomy 21 and a history of congenital lagopthalmos tarsorraphy and ectropion repair with a resulting PKP was successfully fit with a scleral lens. A stock scleral lens was initially placed in the eye during anesthesia as it was necessary to get a scleral on the eye as soon as possible, even if not the best lens. A custom scleral lens was subsequently made in part due to the necessity of a steeper vault and the patient wore the lens overnight.

GENERAL SESSION #2: INTERNATIONAL PERSPECTIVES—A RESEARCH UPDATE FROM AROUND THE GLOBE

After a few years of little international travel, this Saturday morning session aimed to join forces again, and “compare notes” on what is occurring internationally—and to increase the scope of topics presented—to obtain an OD/MD perspective, including corneal surgical approaches for keratoconus. As much as possible, an evidence-based practice approach was applied.

The first part, presented by Dr. van der Worp from the Netherlands, covered corneal GP and soft specialty lenses. According to an international survey published in the January issue of CLS, about 12% of new fits around the world are with rigid lenses, added on with about 2% orthokeratology (ortho-k) (14% in total).¹

What is striking, though, is that there are considerable differences between countries in the rigid lens category—something we do not see as much in the soft lens arena. Developments in the corneal rigid lens arena mostly focus on topography-based fitting and free-form lenses; major improvements are possible. In that regard, the corneal GP lens should potentially be considered slightly more often for the not-too-irregular cornea. This is something that also was reflected in several posters presented at this GSLS.

While the frequency of keratoconus is much higher than originally thought, and we see less severe cases of keratoconus because of corneal cross-linking (CXL) and improved techniques of corneal transplants, there seems to increasingly be a place for soft specialty lenses as well. Four categories can be defined: 1) using standard lenses using the sagittal depth charts, 2) using out-of-standard parameter lenses, 3) custom-made lenses, and 4) special lenses for keratoconus with increased center thicknesses.

During the second part, Stephen Vincent, BAppSc(Optom)Hons, PhD, from Brisbane, Australia, focused on scleral lens research and ortho-k. Based on his own research that has looked at lens thickness, Dk of the material, and fluid reservoir thickness,^2-6 he concluded the key clinical take-home message: If a lens Dk is greater than 100, then practitioners should prioritize minimizing fluid reservoir thickness for most effect in improving oxygen supply to the cornea.

Theoretical models can overestimate the effect of manipulating these variables upon corneal edema, he stated. He also looked at fenestrations (very limited effect) and higher-order aberration (HOA) correction. The latter is a very promising but complex development.

The topic of aberrations was further extended into the ortho-k department. The key visual signal to myopia control seems to be spherical aberration. Can this be enhanced by modifying the lens fit? It seems so by using various parameters including back optic zone diameter, and treatment zone.^7-11

Dr. Koppen from Belgium was asked to cover keratoconus and hot topics in managing the disease. Eye rubbing remains a crucial part of keratoconus management in any practice dealing with these patients. In a very balanced overview, carefully weighing the pros and cons, she covered CXL. The many benefits of this technique seem to outweigh the risks—although CXL was not found to be safe in all patients. In addition, she looked at corneal ring segment implantation and donor ring implants and other inlays. The successful adaptation of scleral lenses over recent years has drastically affected the surgical volume in keratoconus patients in her clinic.

GENERAL SESSION #3: COLLABORATIVE CARE IN MYOPIA MANAGEMENT

This session, led by Ian Flitcroft, MA, DPhil (oxon), FRCOphth, and Kate Gifford, PhD, BAppSc(Optom)Hons, GCOT, explored ophthalmology and optometry perspectives focusing on collaborative care in myopia management. The first portion of the session asked a question: What are the opportunities and challenges of collaboration and comanagement? Opportunities include improved patient care, greater access to care, more efficient use of resources, and enhanced patient education. Challenges in collaboration include differences in training and scope of practice, limited time and resources, and legal and regulatory barriers.

However, the importance of collaboration was underscored for safe patient care in “red-flag” cases and providing best-practice patient care. A simple rule of thumb was shared: If a child has more diopters than candles on their birthday cake, this is cause for immediate alert.

Key questions addressed included:

Should optometrists or ophthalmologists be taking the lead in myopia control? Professor Flitcroft stated that this should be answered on a case-by-case basis. In other words, myopia control is not firmly an optometric nor ophthalmologic activity. There is variation in scope of practice across the world and therefore no one-size-fits-all strategy.

What are first line-treatment choices? This explored optical treatments (spectacles and contact lenses) and pharmacological treatments (atropine).

Are current optical prescriptions issued by ophthalmologists fit for purpose? Professor Flitcroft noted that if atropine is used in an ophthalmological setting, it’s essential that that information gets included on the glasses’ prescription. That way, the information is conveyed clearly to parents of the myopic children.

Are there any myopes who are best managed in secondary or tertiary care settings? Red-flag cases include myopia of prematurity, syndromic myopia, and myopia combined with neurodevelopmental disorders.

Do other eye conditions provide frameworks for shared care? Glaucoma, strabismus, and amblyopia.

The second part of the session focused on four case studies with an interactive polling option for attendees that asked about their main clinical concern for the patient. Information on these case studies is presented in the Mastering Myopia column on page 17.

GSLS RISING STAR AWARD

New for 2023, this award is intended to recognize an emerging leader in the field of cornea and contact lenses. The awardee must demonstrate substantial contributions to the field, outside of what might normally be expected in this early phase of one’s career. The recipient of the inaugural award is Stephen J. Vincent, BAppSc(Optom)Hons, PhD. Dr. Vincent is an associate professor at the Queensland University of Technology, Australia, and is international relations chair of the Scleral Lens Education Society. He is also a member of the International Advisory Group of the GSLS, a committee member of the Cornea and Contact Lens Society of Australia, and chair of the Optometry Council of Australia and New Zealand Examination Eligibility Committee.

GENERAL SESSION #6: FAST FORWARD TO THE FUTURE: NOVEL CONTACT LENS INNOVATIONS

During this one-hour session, Lyndon Jones, PhD, DSc, highlighted information that was previously published in one of the Contact Lens Evidence-based Academic Report (CLEAR) papers from the British Contact Lens Association (BCLA).¹²

First, he talked about products that are currently available, such as photochromic contact lenses, lenses that included sensors for diagnosis and/or screening of systemic diseases, and lenses that can be used for drug delivery. He noted that more than 250 patents have been granted over the last decade and that many have gone to companies that are not traditionally in the medical or health care space. Dr. Jones concluded that rapid growth in novel biomaterials and the development of powered contact lenses through advancements in nanotechnology will enable the commercialization of lenses that can both detect and treat ocular and systemic disease.

According to Dr. Jones, this area will certainly expand over the next five to 10 years. He noted that the industry is starting to see more research on the topics of antimicrobial lenses, antibacterial storage cases, and contact lenses with optical enhancements (e.g., virtual reality overlays, zooming for presbyopes, etc.). He concluded that novel optical designs would provide enhanced vision for patients who have low vision and a wide variety of other optical considerations.

GENERAL SESSION #7: GSLS 2023 FREE PAPER SESSION

During this session, which was moderated by Dr. van der Worp, there were five brief presentations on studies and projects in contact lenses presented by the authors.

To start, Javier Rojas Viñuela, GO, MSc, compared sagittal heights calculated using corneal parameters and those measured with profilometry. In this study, corneal parameters recorded included flat and steep keratometry, flat and steep eccentricity, horizontal and vertical visible iris diameter, and inner corneal radius. Then ocular sag was measured at the 11mm, 14mm, 14.5mm, and 15mm chords. Then, the researchers calculated corneal parameters with various ways. The researchers determined that calculated and measure values of the ocular surface sagittal heights are not the same (beyond the cornea). Additionally, there was a clear jump at the corneal scleral junction angle.

Next was a presentation by Juan Gonzalo Carracedo Rodríguez, PhD, who compared the visual performance of two multifocal scleral lens designs, with conventional optics and decentered-optics, and a monofocal design. After evaluating binocular defocus curves, stereopsis, and subjective quality of vision and comfort results from the 10 study participants, he concluded that multifocal scleral lenses with decentered-optics design showed better visual performance compared to conventional multifocal design and spectacle correction.

Then, Tony Hough looked at the characteristic power profile of three soft contact lenses intended for myopia management. In the study, five independent measurements were taken for each of three lenses in each of the nine labeled powers (135 independent measurements per product). Based on the results of this work, the medium- and long-term outcomes for myopia management using the products here would not be similar. Additionally, he determined that the quality of vision with all three products to be inferior to single-vision minus-powered soft lenses.

Raymond Chartier, OD, presented fourth. The purpose of this research was to determine whether corneal shape at a 10mm chord is predictive of corneal shape at a 16mm chord, to find out whether it can possibly assist in scleral lens fitting. In this study, corneal and scleral topography was obtained on 30 eyes of 15 subjects who did not have irregular astigmatism. The sagittal depth and toricity of the flat and steep meridians at a 10mm corneal chord were then compared to those measurements at a 16mm scleral chord. The data was analyzed with power vectors.

Dr. Chartier concluded that in regular eyes, without ectatic pathology, there does seem to be a minor correlation between corneal and scleral toricity in with-the-rule and against-the-rule corneas. However, for corneas with irregular astigmatism (i.e., keratoconus) the results and conclusions cannot be applied.

The final paper, presented by Erin Tomiyama, OD, PhD, sought to assess the real-world efficacy of peripheral defocus contact lenses (PDCLs) and ortho-k in an academic myopia management service. Dr. Tomiyama noted that there was no difference in annualized axial length growth between PDCLs and ortho-k in this retrospective analysis of real-world clinical data. In addition, the axial length progression from this setting is consistent with those reported in randomized clinical trials.

GENERAL SESSION #8: SCLERAL LENSES: BIG LENSES, BIG INNOVATIONS.

The session was moderated by Dr. Wallace-Tucker with presentations from Muriel Schornack, OD; Roxana Hemmati, OD; Sheila Morrison, OD; and Jason Marsack, PhD.

Dr. Schornack presented on recent research in scleral lenses. This included the improved performance of more recent custom designs. It was found that the use of a data-driven, quadrant-specific scleral lens resulted in visual improvement, a reduced need for middle of the day removal, and only two lenses on average necessary to complete the fitting process.¹³ Likewise, in a comparison between quadrant-specific and spherical haptic scleral lenses, the quadrant-specific design was rated more favorably in comfort, with greater freedom from dryness, and improved lens cleanliness.¹⁴

In addition, she reported on the recent findings based upon the Scleral Lenses in Current Ophthalmic Evaluation (SCOPE) survey-based study, which focused on corneal complications associated with scleral lens wear.¹⁵ The incidence of four complications, in particular, are shown in Table 1.

Dr. Hemmati discussed scleral uses other than keratoconus. In particular, she mentioned the following benefits/applications of scleral lenses:

Non-Keratoconic Infections and Scars Scleral lenses create a new clear liquid and lens layer over the scar and mask any irregularities from the scar to improve vision. Long term, they can potentially reduce the density of the corneal opacity, reduce corneal neovascularization, and improve visual acuity.

Ocular Surface Disease Although not the initial nor only treatment, there’s likely nothing better for protecting the cornea, improving symptoms, and decreasing light sensitivity in moderate-to-severe dry eye than scleral lenses. In Sjögren’s, scleral lenses can protect the ocular surface, improve vision, and improve comfort of eyes. In limbal stem cell deficiency, scleral lenses protect the limbus from mechanical trauma while maintaining a well-lubricated ocular surface.

Salzmann’s Nodular Degeneration With this condition, scleral lenses improve vision (due to irregular cornea) and improve comfort resulting from dryness.

Exposure Keratopathy During daytime wear, scleral lenses can act like an ocular shield to protect the cornea from drying and support corneal surface healing. Overnight scleral lens wear can provide protection and may be used in combination with other treatments such as ointment, lid taping, and a sleep mask.

Neurotrophic Cornea In cases of neurotrophic cornea, scleral lenses—in combination with lubrication and other treatments—act as a protective shield and can improve vision if scarring is present.

Persistent Epithelial Defects (PEDs) Patients who have PEDs are difficult to manage as they are typically resistant to traditional therapies. Scleral lenses can be beneficial by protecting the cornea from the shearing forces of eyelid blinking, maintaining a stable tear film, and promoting reepithelialization in patients who have nonhealing epithelial defects.

Graft-Versus-Host Disease (GVHD) In GVHD, scleral lens therapy promotes healing of surface epitheliopathy while improving pain and photophobia associated with chronic ocular GVHD.

Next, Dr. Morrison presented on technology-driven scleral lens fitting. She described lessons that we have learned from scleral shape studies,^15-18 including: 1) Toric haptics are more likely to be successful than spherical ones; 2) Quadrant-specific or asymmetrical is more likely to be successful than toric; 3) Scleral lens fitting should be driven toward more toric haptics in general and quadrant specific or freeform as technology allows; and 4) Correlation between cornea and sclera needs further study. The comparison of scleral lens fitting techniques is presented in Table 2.

Dr. Marsack concluded the program by discussing wavefront-guided contact lenses. He indicated that, although visual performance is improved with the optics of a rigid lens in keratoconus patients, elevated HOAs are still present resulting in compromised visual performance. He concluded by stating that: 1) The clinician’s percept of disease burden may be much lower than that of the patient because all the common clinical measures are telling the clinician the lens is performing well when in fact the patient’s expectations may not be getting met; and 2) Wavefront sensing and wavefront-guided corrections are an opportunity to improve the visual outcomes for individuals who have visual complaints.

GENERAL SESSION #9: CORNEAL GP LENSES... ALIVE & WELL

Patrick J. Caroline and Randy Kojima presented a very clinically based overview of how to optimize corneal GP lens designs based upon corneal topography. Their insights included the following:

Lens movement is what really affects the initial comfort and adaptation time of any contact lens. If you want to address GP lens comfort, you need to address movement. A larger diameter is half the battle in slowing down lens movement and improving comfort. But surprisingly, it’s not the whole story.

Reducing the channel of fluid along the steep meridian contributes significantly to reducing movement. Coupled with a large diameter, the extra sag, and 360° uniform alignment makes a big difference to comfort. The uniform alignment given above is easier to accomplish in a normal eye, but the irregular cornea becomes much more of a challenge as one would expect.

To improve corneal GP fitting in the irregular eye, some kind of topography derived shape (TDS)—like the scleral world employs using a scanned mold of the eye shape—would be optimum. Topographical elevation analysis would likely suggest that symmetric or toric construction may not be adequate to fit the asymmetric surfaces we face.

The elevation differential along the axis of greatest change (8mm chord) is a good predictor of when our current corneal GP technology can be successful. Elevation differentials of 200μm or less can yield a > 90% success rate.²⁰ However, when the elevation differential is > 400μm, then a scleral lens is really the best option. The interesting range is 200μm to 400μm. One-third of these patients can be fit in corneal GP lenses. However, it is still important to understand when corneal GPs fail and when they can be successful in this range.

Finally, can asymmetric landing improve corneal GP success? With asymmetric landing or TDS, can we fit a higher percentage of patients in the 200μm to 400μm elevation differential range? One would expect so, but this remains to be proven.

The bottom line is that the future for corneal GP lenses is exciting. Practitioners just need to improve their understanding of how to use computer-generated lens platforms, and there is still much to learn in terms of what tear layer and lens-to-surface relationships should exist when we have levels of construction control that we didn’t employ previously. CLS

References

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