Significant microstructural changes — including central cornea basal cell density, corneal epithelial thickness, and corneal nerve fiber length — are linked with limbal stem cell deficiency (LSCD). Multimodal imaging, such as in vivo laser scanning confocal microscopy (IVCM) and anterior segment optical coherence tomography (AS-OCT), can visualize these structures and differentiate normal corneas from eyes with eyes LSCD, according to research published in Ocular Surface.
Previously, clinicians used medical history and clinical signs to diagnose a patient with LSCD. Impression cytology was the “gold standard” for diagnosis. However, the diagnostic test’s sensitivity is affected by several factors, and clinical presentation and impression cytology often are not enough to accurately stage the severity of the condition.
Studies have confirmed that IVCM and AS-OCT can accurately diagnose LSCD. Both imaging methods can reveal the cellular changes in the cornea and limbus that patients with LSCD experience, according to researchers. These morphologic changes of the epithelial cells in the cornea often precede the clinical signs of LSCD. In addition, earlier studies have shown that basal epithelial cell density and epithelial thickness are negatively correlated with the clinical stage of LSCD and can be used to improve the sensitivity and accuracy of diagnosis.
Investigators in the current study sought to develop an objective system to detect and stage LSCD using in vivo parameters. A total of 126 patients with LSCD (172 eyes) and 67 healthy patients (99 eyes) were included in this observational study. Researchers performed slit-lamp biomicroscopy, IVCM, and AS-OCT.
They found that an increased clinical score was linked with decreased central cornea basal cell density, limbal basal cell density, corneal epithelial thickness, mean and maximum LET, corneal nerve fiber length, corneal nerve fiber density, corneal nerve branch density, and tortuosity coefficient. Armed with this data, investigators created a comprehensive LSCD grading formula based on a combination of these parameters.
A limitation of this study is that IVCM may not be available in all tertiary eye centers.
Le Q, Chauhan T, Cordova D, et al. Biomarkers of in vivo limbal stem cell function. Ocular Surface. Published online December 8, 2022. doi:10.1016/j.jtos.2021.12.005.