More than 1,000 contact lens fitters, educators, researchers, manufacturers, and enthusiasts from 34 countries, 42 states, and Puerto Rico came together in Las Vegas from Jan. 24 to 27 to take part in the 2019 Global Specialty Lens Symposium (GSLS), presented by Contact Lens Spectrum. Featuring nearly 50 continuing education (CE) courses, close to 45 non-CE education sessions, more than 100 posters, and 59+ exhibiting companies, the symposium offered learning opportunities on all aspects of specialty contact lenses. The educational program was developed by the GSLS Education Planning Committee, chaired for the first time this year by Jason J. Nichols, OD, MPH, PhD, and including Edward Bennett, OD, MSEd; Karen DeLoss, OD; Eef van der Worp, BOptom, PhD; and Patrick Caroline (Figure 1).
The Preconference program is produced in collaboration with specialty lens educational organizations. This year, it featured five tracks that included GPLI, co-hosted by the GP Lens Institute (GPLI); Myopia, hosted by Contact Lens Spectrum; Practice Management, co-hosted by Optometric Management magazine; Keratoconus, co-hosted by the International Keratoconus Academy of Eye Care Professionals; and Scleral Lenses, co-hosted by the Scleral Lens Education Society (SLS).
This article presents clinical and research highlights from the CE sessions of this year’s meeting.
A favorite tradition continued this year with a presentation of the GSLS Award of Excellence. This year’s honoree was Craig Norman (Figure 2), who started the GSLS in 2009. He has served in a variety of roles throughout his professional career and he has been a colleague, friend, and mentor to us all. The award was given to celebrate his vision to grow specialty contact lenses through the GSLS. While Craig’s passion is in specialty contact lenses, he is particularly known for his clinical, scholarly, and educational contributions in the area of presbyopia and multifocals.
This year saw 134 entries in the poster competition. Six individuals received recognition for their submitted posters (Figure 3). Three awards were provided in each of the scientific and clinical categories (see sidebar on page 22).
In addition, the Scleral Lens Education Society (SLS) presented travel grants to Emily Cheng, OD, of Pacific University for her poster titled “Does the pH of Scleral Lens filling solutions affect the comfort in normal and dry eye patients?” and to Gabriella Courey of the University of Montreal for her poster titled “Prevalence of Residual Astigmatism Following Scleral Lens Wear in Keratoconus Patients.”
There were also three winners (Figure 4) in the annual GSLS Photo Contest (see sidebar on page 22), which had more than 25 entries this year. The award-winning photos are pictured on the cover of this issue.
An interesting new addition to the GSLS program was a session on clinical controversies with regard to three timely and popular topics: 1) Should scleral lenses be fit on healthy eyes? 2) Which is preferable for the irregular cornea: corneal or scleral GP lenses? and 3) Is orthokeratology (ortho-k) or are peripheral-plus soft lenses better for myopia control?
Derek Louie, OD, presented the “pro” side on the scleral lens topic. He mentioned the importance of presenting all reasonable options to patients so that they can make an educated decision.1 He reviewed the results of a crossover study of soft toric wearers conducted by Michaud et al2 in which one group of subjects wore soft torics initially and then crossed over to sclerals, and the second group did vice versa. At the conclusion, 75% preferred the vision of the scleral lenses, and 52.7% preferred to stay in scleral lenses despite having worn soft torics prior to the study. Jeffrey Sonsino, OD, presenting the dissenting opinion, emphasized that, although scleral lenses are an option for healthy astigmatic and presbyopic individuals, they are more expensive, more difficult to apply and remove, require specific solutions, require greater expertise to fit, and require a greater number of visits and potential lens exchanges. He said that the many other viable lens options should be considered first.
On the second controversies topic, Loretta Szczotka-Flynn, OD, PhD, argued in favor of corneal GP lenses. Many irregular cornea patients have a compromised endothelium prior to contact lens wear; thinner corneal GP lenses result in much greater oxygen transmission. In addition, with corneal GPs, there is rare incidence of corneal abrasions, infection, neovascularization, and graft decompensation as well as no impact on limbal stem cells. Muriel Schornack, OD, provided support for scleral lenses as a primary contact lens modality for irregular cornea patients. She quoted a study showing the benefits of scleral lenses versus keratoplasty in corneal ectasia3 and one indicating that scleral lenses can reduce the need for corneal transplants in severe keratoconus.4
Bruce Williams, OD, presented the benefits of ortho-k for the final controversy. He noted that no corrective device worn during the day means no restrictions for young people playing sports as well as no lost or displaced lenses or broken glasses. However, parents play an important role in proper care and handling. Jeff Walline, OD, PhD, made the argument for soft multifocal lenses. He reported that more soft multifocal lens options are becoming available and that these patients are less likely to drop out of lens wear. They are also much more likely to have parents who are soft lens wearers as opposed to GP wearers.
With the increasing emphasis on the need for ECPs to incorporate some types of myopia control modalities into their practice, this was a major emphasis at the GSLS. In the general session “Myopia Control – A Panel Discussion,” world-renowned myopia expert Dr. Pauline Cho discussed a study in which she and her colleagues found that discontinuing ortho-k lens wear before 14 years of age resulted in a more rapid increase in axial length.5 This was comparable to those subjects wearing spectacles during the initial two-year myopia control study, but was greater compared to the control subjects and to the ortho-k subjects who did not discontinue lens wear. Axial length slowed again when ortho-k lens wear was resumed after six months. Dr. Cho also reviewed two other studies6-8 that showed that ortho-k significantly reduced the risk of rapid progression in the younger cohort (6 to 8 years of age) of subjects.
Patrick Caroline reviewed a study performed with Dr. Cheng at the Pacific University College of Optometry. They evaluated the power profiles of nine commonly prescribed daily disposable lenses. All had an increase in minus power in the paracentral and midperipheral regions of the lens, which, in theory, would increase myopia progression. Lenses that had a central power of –0.50D resulted in a power at 3.0mm away from the center that ranged from –0.67D to a remarkable –3.87D. Going out to a –12.00D lens, the range at 3mm from the center was –12.79D to a remarkable –17.44D. Patrick Caroline suggested that, similar to the tobacco industry, perhaps a warning should be provided on certain minus lenses indicating that “Minus Powered Contact Lenses...may cause increasing myopia and increase the risk for cataracts, glaucoma, and retinal pathology.”
Interestingly, in a Preconference Myopia session, Dr. Walline stated that the amount of myopia progression induced by single-vision lenses is actually very low. He said that it does not necessarily harm patients to prescribe single-vision lenses because the “grow” signal is much weaker compared to the “slow” signal.
Melanie Frogozo, OD, also focused on myopia management in her lecture “Bringing Myopia Management to Your Practice.” She reviewed methods of slowing down myopia, including ortho-k, soft bifocal contact lenses, and antimuscarinic agents. Soft bifocal lenses appear to use the same mechanism that ortho-k does for slowing myopia progression, namely peripheral retinal myopic defocus, and their effect on slowing myopia progression appears to be similar. Dr. Frogozo discussed a study in which the effect of different concentrations of atropine (0.01%, 0.025%, and 0.05%) on refractive efficacy and axial efficacy were evaluated.9 The results indicated that 0.05% atropine would be recommended for myopia control, as the effect on refractive change was 66% (versus 27% for 0.01%) and on axial growth was 51% (versus 12% for 0.01%).
SCIENTIFIC POSTER & PHOTO AWARDS
SCIENTIFIC CATEGORY POSTERS
FIRST PLACE: Lacey Haines, O. Kraji, Sebastian Marschall, et al – Association of Pre-Operative Factors with Corneal Thickness Changes After Crosslinking Surgery
SECOND PLACE: Lyndon Jones, Emma Dare, Chung Ki Fung, David McCanna, and Lakshman Subbaraman – Establishment of Optimal Culture Media in Human Corneal Epithelial Wound Healing Models
THIRD PLACE: Frank Spors, Jie Shen, Dorcas Tsang, et al – A Comparison of Manual Keratometry and Simulated Keratometry When Determining Central K-Readings
CLINICAL CATEGORY POSTERS
FIRST PLACE: Carol Yu, Anisha Patel, and Chandra Mickles – Scleral Lens Success with Corneal Dystrophies
SECOND PLACE: Florencia Yeh, Robert Fintelmann, and Tina Zhu – Inflammatory Corneal Neovascularization from Hybrid Lens Wear
THIRD PLACE: Melanie Frogozo – Hybrid Multifocal Contact Lens Design for Myopia Management in Astigmatic Children
PHOTO CONTEST WINNERS
FIRST PLACE: Lindsay Sicks, Charleux Sign
SECOND PLACE: Daniel Deligio, The Depth of an Intrastromal Ring
THIRD PLACE: Catherine Wright, Meeting in the Middle
From a practice management standpoint, Dr. Frogozo recommended using corneal topography, biometry, pachymetry, diagnostic fitting sets, a radiuscope, and optical coherence tomography (OCT) to practice myopia management. Staff should be educated so that they can discuss myopia management with current and future patients. In addition, a dedicated staff member should be able to answer questions, discuss the financial commitment, and provide an informed consent.
The closing session of the GSLS, “An International Perspective (Is It Time to Go Public with Myopia Control as Eye Care Practitioners?),” moderated by Dr. van der Worp and featuring Dr. Cho; Langis Michaud, OD, MSc; and Stephen Vincent, BAppSc(Optom)Hons, PhD, discussed what practitioners can reasonably tell their patients at this point in time about myopia control based on current clinical evidence. Recommendations included that there is a need to reach out to both parents and schools about the importance of kids playing outside more to delay onset and that practitioners can tell parents/patients that treatments are available that can reduce myopia progression. The panel further recommended that the information about myopia, its progression, and possible treatments should be provided to all myopic patients/parents, but treatment can be delayed.
A popular topic at every GSLS is scleral lenses, and this year was no exception. During the Preconference session “The Diameter Debate: Mini Scleral and Large Scleral Pros and Cons,” Drs. Lynette Johns and Stephanie Woo began by defining what is meant by a “large” scleral lens. A corneo-scleral lens has been defined as having a diameter between 12.9mm and 13.5mm, a semi-scleral is 13.6mm to 14.9mm, a mini-scleral is 15.0mm to 18.0mm, and a full scleral is 18.1mm to ≥ 24.0mm.10,11 But the case was made that lens size is irrelevant because it’s really about where the scleral lens rests on the eye.
Dr. Johns argued in favor of larger sclerals. She pointed to the fact that the weight of the lens was distributed better on the eye, reducing the likelihood of compression on the cornea. Dr. Johns also noted that larger scleral lenses can help increase ocular surface protection; this is especially helpful with patients who are suffering from severe dry eye. She did note that in cases of ocular obstacles—such as pinguecula, trabeculectomies, and symblepharon—smaller lenses may be more appropriate.
Dr. Woo spoke on the other side of the debate and made a case for smaller sclerals. A poll taken during the session confirmed that nearly two-thirds of those in attendance fit mostly smaller sclerals (16.0mm or smaller). Good normal-eye candidates for sclerals include those who have smaller horizontal visible iris diameters or who have conjunctival anomalies. Dr. Woo noted that smaller sclerals may not be appropriate for patients who have severe ocular surface disease, extreme irregularity or ectasia, or for those who have conjunctival anomalies that cannot be vaulted.
At the end of the session, both Dr. Johns and Dr. Woo agreed that scleral lens diameter selection is ultimately patient-, and sometimes eye-, specific.
During the “Long-Term Scleral Management” breakout session, Dr. DeLoss; Dr. Johns; Jennifer Harthan, OD; and Gloria Chiu, OD, talked about the process that practitioners should undertake when seeing their scleral lens-wearing patients and about long-term issues that can come up with scleral lens wear.
Dr. Johns began with an overview of the issues. To start, ask about average wear time. Next, see whether patients are experiencing any symptoms. Is their vision compromised in any way? Are they experiencing any debris, and what do they do if that occurs? Are they experiencing any lens discomfort? If so, is there a pattern (e.g., at a specific time of day)? Be sure to rule out any missteps with the lens care routine. Dr. Johns emphasized the importance of asking open-ended questions about filling, cleaners, disinfection, storage, and rewetting to get a clearer picture of what patients are and aren’t doing properly.
Practitioners need to assess the eye both with and without the lens. The presenters emphasized the importance of allowing time for the scleral lens to settle on the eye before making any determinations about fit. Assess the peripheral cornea and limbus12 and the conjunctiva without the lens; specifically, look for any compression, impingement, or edge lift. Be sure to check for any suction when the lens is removed as well as any corneal staining, bogging, or neovascularization. Dr. Johns noted that removal issues are a red flag with patients who have had corneal transplants.
Practitioners also need to evaluate the lens itself. Once all assessments are completed, the critical step, Dr. Johns said, is piecing together all of the signs, symptoms, and measurements to determine what issues are present and what follow up is necessary.
Drs. Harthan, Chiu, and DeLoss then presented some case studies. In all of these cases, the presenters emphasized the need for careful and thorough observation and follow up. In addition, practitioners should be aware of the emotional support that many of these patients may need while going through this process, especially in the case of extreme ocular conditions. Other pearls learned through the cases included the importance of talking to patients about how they dose medications while using scleral lenses (i.e., timing), a recommendation of stocking needed supplies in the office where patients can easily purchase them, and a need for patients to take midday breaks and refresh the saline when needed.
SOFT SPECIALTY LENSES
Specialty soft contact lenses are an important part of contact lens practice for patients who have difficulty achieving acceptable comfort or vision with standard soft or GP lenses. Patrick Caroline moderated the session “Soft Specialty Lenses: A Panel Discussion.” Stephanie Ramdass, OD, MS, MBA, kicked it off with a discussion of a study from the Michigan College of Optometry13 that compared visual performance in multifocal lenses with the optics in the center of the lens versus 1mm offset nasally from the center. The subjective responses indicated that the offset optics provided better quality of near vision while distance vision remained the same. Dr. Ramdass recommended that practitioners develop a fitting process, perform a thorough examination, set realistic expectations, use instrumentation, customize the lenses, and start early to optimize presbyopes’ vision.
Dr. van der Worp stated that there is a need to bring the “fitting” back into soft lens fitting. He indicated that about 68% to 78% of normal eyes—what he called Normal Eyes Measured Ocular Surface (NEMOS)—can be successfully fit with the standard soft lenses currently available. When practitioners “find NEMOS,” standard lenses can be fit. But for eyes outside of this range, perform topography of the entire eye and custom design lenses in a lathe-cut silicone hydrogel material.
Matt Lampa, OD, presented “A Contemporary Look at Soft Contact Lenses in 2019.” He discussed data collected by Dr. Ben Coldrick, head of Technical Development of Optimec Ltd, who measured the sagittal heights of a number of currently available soft contact lenses using the Optimec Is830 lens imaging system. The data show that while there may be two lenses that are labeled with the same base curve and diameter—as if they would fit the same—their sagittal depths can differ by several hundred microns. In addition, among the daily disposable spherical soft lenses measured, there was a difference of 521 microns between the lowest sag and the deepest sag. Furthermore, there is a range of 214 to 329 microns difference when measuring sagittal heights between two daily disposable lenses of the same brand that are available in two different base curves (average is 274 microns).
For reusable lenses, the difference in sags between the lenses studied was 633 microns. Among toric soft lenses, the difference in posterior sag depth from lowest to highest was 631 microns. Dr. Lampa suggested that knowing these values could help with selecting the most appropriate initial lens brand and base curve for smaller or larger corneas.
Patrick Caroline concluded the session by stating that it is time for the soft lens industry to start looking beyond base curve and diameter and to consider other metrics, particularly sagittal height.
CARE OF SPECIALTY LENSES
Contact lens care may be one of the most underrated topics in specialty lens practice. Much attention in the specialty lens field goes to the fitting process, indications, complications, etc., but a large part of the success—or failure—of specialty lenses relies on contact lens solutions, hygiene, and handling. The general session “Care and Aftercare of Specialty Lenses” focused first and foremost on the risk of a microbial keratitis (MK). As Dr. van der Worp—moderator and organizer of this session—pointed out, this risk is generally considered to be low with corneal GPs, which has always been the safest lens modality by far because of the high oxygen supply to the cornea and good tear mixing.
The MK risk is somewhat higher in daily wear (DW) and is significantly higher in extended wear (EW) of soft lenses. Ortho-k is thought to be somewhere in between DW and EW soft, but this is difficult to determine because the absolute number of ortho-k lens wearers is much lower.
The risk with scleral lens wear is even harder to predict, given that the absolute number of wearers is limited and that most of the wearers by default have compromised corneas (irregular corneas, severe dry eye, etc.) Apart from the challenging corneas, the biggest differences as opposed to corneal GPs are that scleral lenses are considerably thicker and their extra “tear layer” or clearance creates another filter that could limit the oxygen supply to the cornea. Also a consideration is the very minimal amount of tear film exchange with scleral lenses.
Despite those factors, the point was made that the real difference is in the handling, compliance, and hygiene department. Optimization of this process starts in the contact lens practice and should be initiated and managed by eyecare professionals.
Dr. Cho presented a fantastic talk about what to do—and not to do—for ortho-k lens care. Ways to prevent or minimize noncompliance and contamination included avoiding unnecessary accessories (often a source of contamination) and choice of lens case design. Replacement of lens cases is an integral part of good ortho-k lens care, in her view. She also advocated that lens cases need to be dried with a tissue and left open upside down on a clean tissue to further air dry. She noted that if cases are kept in the bathroom, the toilet seat lid should be closed when flushing to prevent micro-organisms from “roaming” the bathroom and settling on cases and solution bottles.
Maria Walker, OD, looked specifically at scleral lenses and solution interactions in scleral lens wear. She started with material choices of current scleral lenses as well as how they are manufactured and treated, including the indications and features of lens coatings and how plasma treatment works to improve surface wettability. She then focused on preservatives in scleral lens solutions: What happens when preserved conditioner is left on the lens and then gets in the fluid reservoir? Apart from comfort issues, this can cause corneal staining; most pathogenic micro-organisms cannot penetrate an intact cornea, so it is important to prevent corneal epithelial staining and to screen for it at every check-up.
Kelsy Steele, OD, MS, presented her thoughts on using tap water in specialty contact lenses, including GPs. Her message was as straightforward as it was clear: no tap water in any shape or form should be allowed in the contact lens care regimen of any lens type. This means that after hand washing, thorough hand drying with a clean towel is indicated to remove any excess tap water. Also, the lens case should not be cleaned with tap water; it should be rinsed with GP conditioning solution, dried with a tissue, and then air-dried with the caps off.
Dave Kading concluded this session by stating that this “academic talk” is all well and good—but what about the practice? For instance, it was pointed out during this session that it takes 53 steps to take care of reusable lenses properly.14 Who does that? How can we best achieve this—at least the main items? Can we—and should we—“dumb it down” a little?
With so much information on the internet, it is important to know how to most effectively share with patients why and how they need to clean their lenses. Research has pointed to more effective and safer ways to manage lenses, and practitioners need to know how to communicate this to patients, Dr. Kading stated. He urged practitioners to better understand their place in educating patients on safety and risks—and the responsibilities that this entails. He also emphasized the importance of understanding patients’ perceptions and how to overcome them (“Try to see it from their point of view.”). He noted that it is critical to understand the complexity of the educational process. How to present risk factors to patients is therefore paramount. It does not work to scare patients, but providing a good understanding of the process—showing them not just what to do, but importantly, how to do it—seems crucial. He further explained the cost benefits for safety and long-term success of lens wear and what this means to a (specialty) practice.
Daddi Fadel, DOptom, and Mindy Toabe, OD, presented the breakout session “How Hygiene, Care, and Compliance Play a Role in Complications Associated with Scleral Lenses.” They noted that even with a good fitting, scleral lens wear will not be successful if there is poor contact lens maintenance. Dr. Toabe advised to rub lenses for 15 seconds during cleaning and then rinse with saline, use fresh multipurpose solution without topping off or to use a hydrogen peroxide system, and to rub and rinse the plunger with sterile lens care solution. Dr. Fadel noted that proper patient education will lower the risk of infection and other complications, stating that most complications are caused by inadequate instructions or poor compliance.
In addition, the appropriate application and removal techniques need to be chosen for each patient, and the patients needs to be thoroughly educated on the techniques used. One study reported that patients who found removal difficult had challenges with plunger positioning and that patients expressed worry over breaking the lens during cleaning or of dropping it.15 To manage the latter, they recommended that patients apply and remove lenses over a soft towel to catch the lens if it falls. They also provided a detailed discussion of care instructions for scleral lenses as well as how to diagnose and manage complications that arise during scleral lens wear.
Post-Surgical Cornea Dr. DeLoss moderated the “Management of the Post-Surgical Cornea (Panel)” general session. Karen L. Lee, OD, discussed various corneal transplant procedures and the contributing factors to corneal graft rejection, including an immunologic response of the host to the donor corneal tissue. She noted that graft rejection usually occurs during one to five years after the transplant, but it can happen up to 20 years after.16 There are both host and donor risk factors that contribute to whether the graft will be rejected. Rejection types include epithelium, stroma, and endothelium. Each can be rejected separately. Practitioners should wait two weeks before diagnosing a rejection, as other conditions may present similar symptoms. A graft failure diagnosis is confirmed when there is no improvement after two months of steroid treatment.
Next, Dr. Harthan tackled visual challenges that patients may experience post-op, such as irregular astigmatism, anisometropia, and higher-order aberrations (HOAs).17-19 She also looked at the optimal time to start fitting contact lenses on these patients after the corneal transplantation. Overall, the goal is to minimize the mechanical and physiological stress and trauma on a patient’s eye. While similar, this process should be customized for each individual patient.
Remember to measure the endothelial cell density. With fitting contact lenses post-op, practitioners should obtain a baseline corneal topography, determine the location of the graft, and assess the degree of elevation/asymmetry. Other considerations include the shape of the cornea and whether there is ocular surface disease. For all contact lens types, consider oxygen transmission to the cornea, lens care, and comorbid ocular and systemic conditions.
Dr. Szczotka-Flynn wrapped up the session with a look at relevant research regarding corneal transplantation. Specifically, she highlighted two studies20,21 that looked at both cornea donors and the viability of those donations over time.
Corneal Cross-Linking Also moderated by Dr. DeLoss, the “Cross-Linking” general session featured Clark Chang, OD, and Dr. Michaud. Dr. Michaud began by defining keratoconus,22 and he noted that there is still debate as to what constitutes progression. According to the Global Consensus on Keratoconus and Ectatic Diseases,23 there is no clear definition of ectasia progression. However, practitioners generally believe that there is progression if they observe an increase of ≥ 1.00D keratometric parameters in 12 months; increase of ≥ 0.75D in keratometric parameters in six months; myopia increase of 0.75D in 12 months in refraction under cycloplegia; increase of ≥ 1.00D in refractive cylinder in 12 months; loss of at least two lines of best-corrected vision in 12 months; and/or evidence of progression on serial tomography/topography (i.e., pachymetric thinning of ≥ 20µm at the thinnest corneal point in 12 months). Dr. Michaud stressed the importance of assessing progression based on clinical criteria and symptoms.
Next, Dr. Chang reviewed possible treatments. He discussed the medical treatment of keratoconus via corneal cross-linking (CXL). But, he cautioned that it’s important to inform patients that CXL is meant to halt progression, but not to correct refractive error. In addition, CXL is being used off-label in some countries for the management of post-op ectasia and treatment of recalcitrant corneal ulcers. There are a few variations of CXL procedures (epi-off; epi-on, including iontophoresis; and accelerated versus standard) that each have both pros and cons. The main goal of the procedure is to strengthen and stabilize the tissue. Contraindications include a cornea < 400µm, steep K > 60D, or a presence of significant deep scars. Dr. Chang noted that one procedure currently being studied is an epi-on, accelerated/oxygen-enhanced CXL. During this procedure, increased oxygen availability in the corneal stroma provided enhanced results because free radicals can be generated more rapidly. He also mentioned that if enhanced oxygen could be provided to the cornea for longer, it could reduce the amount of riboflavin that needs to be instilled during the procedure.
Practitioners in the United States can learn from their Canadian peers because CXL has been available in Canada since 2008. Both Dr. Michaud and Dr. Chang agreed with these takeaways: 1) early detection is key, 2) implement a conservative approach or proactive risk assessment, 3) refer promptly, and 4) educate patients about what CXL is and is not (i.e., it is not to restore shape and function, and it is not intended for refractive correction).
As always, a number of outstanding free papers were presented that provided results of cutting-edge research in areas of much interest to attendees. Scleral lenses once again predominated. Some of these presentations are summarized below.
Dr. Michaud presented recently published research on the topic of “Intra-ocular pressure variation following scleral lens wear.”24 He and colleagues evaluated variation of intraocular pressure (IOP) during short-term (average of five hours) scleral lens wear. One eye was fitted with a 15.8mm overall diameter scleral lens while the other eye was fitted with an 18.0mm lens of similar design, thickness, and material. They found that scleral lens wear can increase IOP by an average of approximately 5 mmHg, regardless of lens diameter.
Melissa Barnett, OD, reported on “Preliminary clinical exploration of scleral lens performance on normal eyes.” The performance of spherical (13 eyes) and front-surface toric (three eyes) scleral lenses were evaluated on subjects who had healthy eyes and who had previously worn either soft toric or corneal GP lenses. Following one month of lens wear, scleral lenses were subjectively preferred over previous contact lens correction in 88% (14/16) of the eyes. No participants reported poor subjective vision and/or comfort. Seventy-five percent of eyes achieved visual acuity of 0.1 logMAR or better.
A topic of great interest is the application—and resulting performance—of lens surface coatings, notably with scleral lens-wearing patients who have a dry eye history. In a paper from Chandra Mickles, OD, titled “A surface treatment solution for scleral lens wearers with dry eye,” 18 scleral lens-wearing subjects who had moderate-to-severe dry eye and who reported lens discomfort completed a double-masked multi-center crossover study. Following a one-week washout period of no scleral lens wear, subjects were randomized to wear either their habitual untreated scleral lenses or treated scleral lenses of the same parameters for 30 days. Following another one-week washout period, the subjects wore the other lens for 30 days. The authors found that lens comfort was significantly better and dry eye symptoms significantly improved with the treated scleral lenses compared to the untreated lenses. Lid wiper epitheliopathy and conjunctival papillae were significantly reduced with treated lens wear. In addition, comfortable lens wearing time was significantly longer and lens fogging was less frequent with the treated lens.
“Effect of ADD and optical zone of a CD multifocal soft CL on relative peripheral refraction and HOAs” was the topic of a presentation from Giancarlo Montani, Dip Optom. The purpose of this study was to investigate the changes in relative peripheral refraction across the horizontal visual field and the effects on HOAs and objective optical quality induced by a center-distance (CD) soft multifocal lens that produces peripheral myopic defocus (MD), with different additions and center distance zones. He recommended the use of a 2.50D add with a 4.5mm center-distance zone even though this could be associated with a mild reduction in vision quality in low levels of illumination.
An important aspect of optimizing the optics of soft and scleral multifocal lenses is to decenter the optics such that the optical center of a lens positions over the patient’s visual axis. This was the focus of the paper “Assessing soft multifocal contact lens centration with the aid of corneal topography” from Dr. Lampa and his research team at the Pacific University College of Optometry. Twenty-nine subjects (58 eyes) were empirically fit into custom soft multifocals. Corneal topography was performed prior to lens wear and after lens application. They found that there was always a temporal misalignment averaging 0.74mm, which, of course, can have a significant effect on vision. Today, it is possible to order custom lenses with offset optics to remedy this problem.
Boris Severinsky, OD, discussed “Pediatric aphakia correction with custom silicone hydrogel lenses: long-term results,” which was a retrospective review of 14 consecutive patients (17 eyes) fit into a novel custom silicone hydrogel lens (PedSH) specifically designed for pediatric aphakia correction. The patients, most of whom had failed with GP lens wear, were fit 4.3 months on average after surgery and were followed for an average of two years. Two patients dropped out, both to undergo an intraocular lens implantation. Ninety percent of caregivers whose children had not been successful with GP lenses expressed a high level of satisfaction with PedSH handling and on-eye stability. Although the number of lenses that need to be replaced in a year was high (i.e., approximately four lenses per year), it was concluded that this lens design appears to be a safe and viable alternative to conventional GP lenses, providing good optical correction and on-eye stability.
MARK YOUR CALENDARS
To get all of this information—and much more—first hand as well as to take part in valuable networking with your colleagues and peers, plan to attend next year’s GSLS meeting from Jan. 23 to 26, 2020, at the Tropicana Las Vegas Hotel. CLS
- Fadel D, Kramer E. Potential contraindications to scleral lens wear. Contact Lens Anterior Eye. 2019 Feb;42:92-103.
- Michaud L, Bennett ES, Woo SL, et al. Clinical Evaluation of Large Diameter Rigid-Gas Permeable Versus Soft Toric Contact Lenses for the Correction of Refractive Astigmatism. A MultiCenter Study. Eye Contact Lens. 2018 May;44:164-169.
- DeLoss KS, Fatteh NH, Hood CT. Prosthetic Replacement of the Ocular Surface Ecosystem (PROSE) scleral device compared to keratoplasty for the treatment of corneal ectasia. Am J Ophthalmol. 2014 Nov;158:974-982.
- Koppen C, Kreps EO, Anthonissen L, et al. Scleral Lenses Reduce the Need for Corneal Transplants in Severe Keratoconus. Am J Ophthalmol. 2018 Jan;185:43-47.
- Cho P, Cheung SW. Discontinuation of orthokeratology on eyeball elongation (DOEE). Cont Lens Anterior Eye. 2017 Apr;40:82-87.
- Cho P, Cheung SW. Protective Role of Orthokeratology in Reducing Risk of Rapid Axial Elongation: A Reanalysis of Data From the ROMIO and TO-SEE Studies. Invest Ophthalmol Vis Sci. 2017 Mar 1;58:1411-1416.
- 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.
- Chen C, Cheung SW, Cho P. Myopia control using toric orthokeratology (TO-SEE study). Invest Ophthalmol Vis Sci. 2013 Oct 3;54:6510-6517.
- Yam JC, Jiang Y, Tang SM, et al. Low-concentration atropine for myopia progression (LAMP) study. Ophthalmology. 2019 Jan;126:113-124.
- GP Lens Institute, Scleral Lens Education Society. Scleral Lens Troubleshooting FAQs. Available at https://www.gpli.info/pdf/GPLISLSTSGuide11017.pdf . Accessed on March 4, 2019.
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