Neurotrophic Keratopathy Found in Eyes With Limbal Stem Cell Deficiency

In a prospective, cross-sectional, comparative study, Niruthisard and colleagues found the presence of neurotrophic keratopathy (NK) in eyes with Stage 2 and 3 limbal stem cell deficiency (LSCD).

For their study, researchers recruited a total of 46 eyes diagnosed with LSCD and 14 control eyes between 2019 and 2022. Niruthisard and colleagues measured corneal sensation using a Cochet-Bonnet esthesiometer and imaged subbasal nerve plexus using in vivo confocal microscopy (IVCM) at the central cornea and four limbal regions. Based on those measurements and images, researchers were able to quantify subbasal nerve density (SND), subbasal nerve length (SNL), and subbasal nerve branch (SNB) density.

The results showed reduced mean corneal sensation in the central cornea and limbal regions in the LSCD group compared with controls (central cornea: 29.2 ± 21.5 mm vs 57.6 ± 5.8 mm; limbus: 33.6 ± 15.1 mm vs 54.3 ± 4.7 mm, respectively; p < 0.001). Further, in eyes with sectoral LSCD, affected regions showed lower sensation compared with unaffected regions (29.1 ± 17.6 mm vs 41.4 ± 18.2 mm, P < 0.001).

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The quantitative analysis showed reductions in SND, SNL, and SNB density in the central cornea of LSCD eyes compared with controls (reductions of 84.6%, 82.6%, and 89.2%, respectively; p < 0.05). The severity of LSCD was negatively correlated with central corneal sensation. However, central corneal sensation was positively correlated with SND, SNL, and SNBD.

“Interestingly, the reduction of corneal sensation was significant in stage 2 and 3 LSCD, but a significant reduction in SND and SNL was detected as early as in stage 1 disease,” the authors wrote in their study. “This observation suggests that a reduction in subbasal nerve precedes clinical detection of neurotrophic keratopathy.”

The study had limitations. For example, the authors noted that the Cochet-Bonnet esthesiometer “has a limited range of testing value.” Additionally, it can be difficult to obtain quality images of eyes with LSCD via IVCM, particularly in eyes with severe LSCD, due to subepithelial scars.

Despite these limitations, the results of the current study support the presence of NK in LSCD.

“Taken together, the current study provides the evidence of neurotrophic keratopathy in LSCD,” Niruthisard and colleagues concluded. “The degree of reduction in corneal sensation correlates with the severity of LSCD. Changes in nerves morphology and density need to be further investigated to confirm their role as additional diagnostic and prognostic markers of LSC function. Whether adjuvant treatment of neurotrophic keratopathy would benefit aid in the management of LSCD remains to be investigated.”

Reference

Niruthisard D, Bonnet C, Fung SSM, et al. Co-existence of neurotrophic keratopathy in eyes with limbal stem cell deficiency. Am J Ophthalmol. 2024 Jun 28:S0002-9394(24)00267-8. doi:10.1016/j.ajo.2024.06.022