THE PRACTICE OF FITTING scleral lenses has grown significantly in recent years, as more practitioners adopt this approach to managing complex corneal conditions. As a result, a growing number of patients are returning months or even years after their initial fittings for reassessments and refits. While duplicating previous lens parameters can sometimes suffice, modifications are often necessary to maintain patient satisfaction.

A key challenge in refitting is managing the compression effects caused by prolonged scleral lens wear. These effects can lead to temporary alterations in the ocular surface profile, significantly impacting the accuracy of fitting assessments (Kaufmann et al, 2015; Otchere et al, 2017). Understanding and addressing these compression-induced changes are crucial for ensuring precise measurements and optimal lens performance.

PROFILOMETRY-BASED AND DIAGNOSTIC FITTING CHALLENGES

Both profilometry-based and diagnostic methods for fitting scleral lenses face challenges due to compression effects from lens wear. Profilometry relies on detailed ocular surface maps, which can be distorted by even slight compression, leading to potential misfits. Similarly, diagnostic fitting requires precise surface assessments, and temporary changes in scleral shape can cause misfits if new lenses are evaluated too soon after lens removal. Consequently, these inaccuracies may necessitate additional adjustments or remakes, making the process time-consuming and costly.

DISCONTINUATION PERIODS

Addressing this concern, practitioners are advised to implement brief discontinuation periods. Determining the appropriate discontinuation period for scleral lens wear remains a topic without a specific consensus in the literature. Several sources offer guidance, but they only provide a range of recommendations based on clinical observations and manufacturer insights.

One recommendation is that patients discontinue wearing scleral lenses for at least 48 hours prior to profilometry measurements (Jedlicka, 2022). This allows the bulbar conjunctiva and sclera to rebound to their natural shapes, minimizing the compression effects that can distort ocular surface maps.

Additionally, a comprehensive review suggests a broader range, indicating that patients may need to stop wearing scleral lenses for three to seven days before their fitting appointments (Visionary Optics, retrieved 2024). This extended period ensures that any remaining compression effects are minimized, leading to more accurate measurements and better-fitting lenses.

MANAGING LENS-FREE INTERVALS

Having a patient discontinue scleral lens wear is often easier said than done. This approach has significant implications for many patients, as they often rely on their scleral lenses for functional vision. Asking them to stop lens wear can mean confinement to their homes, inability to work, or other significant lifestyle disruptions.

For patients who do not have functional vision with spectacles, our office offers some of the following practical solutions to assist patients during this difficult time:

• Monocular Wear  Have the patient discontinue lens wear in one eye. Once that planned desired time has passed, evaluate that eye and then the patient can do the same process for the other eye. Ensure that the patient can drive with glasses or only one contact lens, or arrange for a driver if they don’t meet legal driving requirements.

• Weekend Break  Encourage patients to discontinue lens wear over the weekend and schedule their mapping appointments on Monday morning. This approach minimizes workweek disruption.

• Low-Dose Steroid  Consider using a low-dose steroid during the discontinuation period (when not using lenses) to accelerate the stabilization process.

Managing compression effects is a critical aspect of refitting scleral lens patients. Ensuring an adequate lens-free period before making assessments can go a long way in avoiding future problems. While this requirement can pose challenges for patients who rely on their lenses for daily activities, implementing practical strategies can help mitigate these challenges and improve fitting outcomes.

REFERENCES

1. Kauffman MJ, Gilmartin CA, Bennett ES, Bassi CJ. A comparison of the short-term settling of three scleral lens designs. Optom Vis Sci. 2014 Dec;91:1462-1466.

2. Otchere H, Jones LW, Sorbara L. Effect of time on scleral lens settling and change in corneal clearance. Optom Vis Sci. 2017 Sep;94:908-913.

3. Jedlicka J. (2022, September 1). Ocular Surface Profiling for Specialty Lens Fitting. Contact Lens Spectrum. 2022 Sep;37:22-24, 26-28, 30-31.

4. Visionary Optics. Why It’s Important Not to Wear Scleral Lenses Before an sMap3D Exam. Available at visionary-optics.com/recent-news/why-its-important-not-to-wear-scleral-lenses-before-an-smap3d-exam. Accessed 2024 May 13.