LOTS OF NEW, interesting, and sometimes fascinating information backed by science was found in the content presented at the recent 2023 Global Specialty Lens Symposium (GSLS) in Las Vegas. On the scleral lens side, it has become clear, if it was not before, that this technology can bring immense benefits to patients of all ages.

During the opening general session, the presenters shared cases in which scleral lenses have made a difference between functional vision and visual impairment in toddlers (Mortensen et al, 2022) and kids (Gungor et al, 2008), sometimes at the expense of fitting patients at home (during COVID time). Obviously, this type of practice is not for everyone, but we must be immensely grateful to those optometrists and ophthalmologists dedicating their careers to these most challenging cases.

As for a more general approach, fitting scleral lenses has never been easier, due to all the technology being developed to image the ocular surface and optimize the vault (Noyes, 2021). With better measurement tools available, we know that the cornea is oval shaped and that the lens vault, both vertically and horizontally, often merits a bi-elevation approach to help balance the fluid reservoir and thus to help reach better lens centration (Jedlicka, 2022).

It has also been known that conjunctival toricity is complex and asymmetric. It is now clear that this toricity does not correspond to that of the cornea. Adapting the peripheral curvature of the lens to such a surface with the classic diagnostic lens method becomes a game of trial and error with more suboptimal outcomes than real successes. A displaced lens leads to reduced visual performance (DeNaeyer, 2015). Decentered optics may then be the ultimate option to improve vision.

This is where the ever-improving imaging and profilometry techniques come in. Practitioners are now able to perform scans that translate into successful fits. Quadrant reading allows for empirical lens designs in most cases. This improves the success rate of the first lens fit. But most important, it improves the patient’s experience: better comfort, less time wasted on multiple visits, and a sense that the prescriber’s skills are enhanced by this technology.

The use of very-high-permeability materials (Dk > 150) helps maintain optimal ocular health (Michaud, 2020). On the other hand, during the International Perspectives’ general session at the GSLS, the presentations informed attendees that it is the profile and thickness of the reservoir that has the greatest impact on hypoxic stress secondary to scleral lens wear (Fisher et al, 2020).

While chronic edema of 2% to 3% may be well tolerated in a normal cornea, experts agree that this becomes an issue to be addressed in more fragile corneas, such as in the case of corneal grafts of older patients (even at 90 years old!). In these cases, a careful assessment of benefit versus expected risk is critical.

The same cautious approach is recommended in the treatment of recurrent erosions or neurotrophic corneas, where extended wear of scleral lenses may be necessary in the short term (Tappin et al, 2001). Rigorous follow-up is then required. However, despite significant edema, ocular health is restored. Extended wear must be discontinued as soon as the restored tissue appears stable.

After reading all of this and attending 2023 GSLS lectures, it’s easy to come to one conclusion: Scleral lenses can benefit everyone, and technology is helping us more than ever to change the lives of our patients…for the better. CLS

References

1. Mortensen ZQ, Simmons BA, Shriver EM, Carter KD, Downes SJ. Scleral Contact Lens as Initial Management in a Neonate With a Large Upper Eyelid Coloboma. Ophthalmic Plast Reconstr Surg. 2022 Jan-Feb 01;38:e10-e13.
2. Gungor I, Schor K, Rosenthal P, Jacobs DS. The Boston Scleral Lens in the treatment of pediatric patients. J AAPOS. 2008 Jun;12:263-267.
3. Noyes M. Scleral Topography: Measuring and Matching its Shape. Rev Cornea Contact Lens. 2021 Sept 15. Available at reviewofcontactlenses.com/article/scleral-topography-measuring-and-matching-its-shape . Accessed Feb. 27, 2023.
4. Jedlicka J. Scleral Lens Case Reports: Clinical Examples of Scleral Contact Lens Design Uses + Fitting Tips. A supplement to Contact Lens Spectrum. 2022 Oct. Available at clspectrum.com/supplements/2022/october-2022/scleral-lens-case-reports-clinical-examples-of-scl . Accessed Feb. 27, 2023.
5. DeNaeyer G. Troubleshooting Reduced Vision. Contact Lens Spectrum. 2016 Mar;31;48. Available at clspectrum.com/issues/2016/march-2016/the-scleral-lens-vault . Accessed Feb. 27, 2023.
6. Michaud L. Defining the GP material of the future. Contact Lens Update. 2020 Feb 6. Available at contactlensupdate.com/2020/02/06/defining-the-gp-material-of-the-future . Accessed Feb. 27, 2023.
7. Fisher D, Collins MJ, Vincent SJ. Fluid Reservoir Thickness and Corneal Edema during Open-eye Scleral Lens Wear. Optom Vis Sci. 2020 Sep;97:683-689.
8. Tappin MJ, Pullum KW, Buckley RJ. Scleral contact lenses for overnight wear in the management of ocular surface disorders. Eye (Lond). 2001 Apr;15:168-172.