Study Tests Scleral Lenses During Therapy for Limbal Stem Cell Deficiency

For patients with limbal stem cell deficiency (LSCD), scleral lenses with liquid reservoir may create a stable microenvironment, and shield the eye’s surface from continual blinking. Visual outcomes have been good, and these lenses — which arch over the limbus and cornea — have become a widely-used treatment option for LSCD.

Prior research emphasizes acuity before and after scleral lens (SL) therapy. An investigation published in Contact Lens and Anterior Eye analyzes vision outcomes and disease stage during treatment, establishing that along with improvements in corrected distance visual acuity (CDVA) and ocular surface stabilization, there is also a possibility SLs can compress the limbus, potentially delaying perfusion in this sensitive region. The consecutive case series examines medical records from 2009 to 2019 of 267 eyes (167 patients) referred to the senior study author at Stein Eye Institute, University of California, Los Angeles. Thirty-five referrals were for LSCD evaluation. Of these, 27 persisted to final fitting of an SL, and the patients attended follow-up visits for a mean duration of 37.1±20.2 months. In 25.9% of these eyes, LSCD severity — graded in stages — improved an average of 3 points; for 29.6%, LSCD score remained even at 5 points; and for 44.4% (12 eyes), the score decreased by an average of 5 points (P =.10) in a mean period of 33.9±26.6 months.

Those with moderate or severe disease stage experienced worsening more often, but risk was not associated with underlying cause (P =.20), or with type of lens — large diameter SL, prosthetic replacement of the ocular surface ecosystem (PROSE), or EyePrintPRO (P =.15). Twelve eyes that displayed progression of LSCD underwent further anterior segment (AS) testing, with 5 eyes exhibiting limbal compression in 1 or more quadrants, and some eyes showing delayed vessel perfusion of 2 to 5 seconds or more.

Nonetheless, SLs demonstrated surface preservation in a majority of eyes, and improved visual outcomes. Mean CDVA before SL fitting was significantly lower than with the SL at baseline (P =.02). At last follow-up, mean CDVA increased in 25.9% of eyes, was steady in 48.1%, and declined in 25.9% of eyes (P =.16).

When fitting SLs, the report suggests it may be best to first use anterior segment optical coherence tomography (AS-OCT) and in vivo confocal microscopy (IVCM) to assess regions of the limbus that still have functioning limbal epithelial cells, because inflammation, corneal neovascularization, and scarring can impact limbal tissue.

It is not clear whether SL shape, size, or ventilation configuration was the optimal factor for fit adjustment, representing a study limitation, as well as the possibility that prior disease therapy such as topical anti-inflammatory drops confounded clinical findings.

Because CDVA was mostly unchanged in eyes with worsening LSCD score, the analysis recommends monitoring disease progression every 3 to 6 months. If severity increases, the SL is one potential reason and fit should be examined after several wear hours, the study suggests. “In addition, evaluating the level of limbal compression and ventilation by AS-OCT after several hours of wear would be informative of the degree of limbal compression by SL,” according to the investigators.

Reference

Bonnet C, Lee A, Shibayama VP, et al. Clinical outcomes and complications of fluid-filled scleral lens devices for the management of limbal stem cell deficiency. Cont Lens Anterior Eye. Published online October 30, 2021. doi:10.1016/j.clae.2021.101528