The lack of consensus regarding limbal stem cell deficiency has been resolved by a panel of experts that provided uniform guidelines for disease diagnosis and staging.
This article was reviewed by Friedrich E. Kruse, MD
The importance of the limbal stem cells was never in dispute, and they are fundamental to regeneration of the corneal epithelium. However, the general good health of the cells must be maintained to ensure that regeneration, and uniform guidelines were absent regarding what exactly constituted limbal stem cell disease.
“The stem cells are the source of the regeneration and maintain a healthy phenotype of the corneal epithelium,” Friedrich E. Kruse, MD, explained, underscoring their importance.
In an unhealthy state when the stem cells are not functioning well, the result is conjunctivalization, in which normal corneal epithelium is replaced by conjunctival epithelium.
“When this happens, the characteristic picture of limbal stem cell deficiency arises,” said Dr. Kruse, professor of ophthalmology, Department of Ophthalmology, University of Erlangen-Nuremberg, Erlangen, Germany.
The potential treatments for the scenario detailed are limbal stem cell transplantation or ex vivo expanded grafts.
Numerous studies have reported the results of limbal stem cell transplantation, with great variations in the diagnostic criteria, staging systems, and outcome criteria, resulting in marked heterogeneity of the clinical picture of stem cell deficiency and potential confusion with other ocular surface diseases, Dr. Kruse explained.
Recognition of the lack of uniformity in the definition and diagnostic criteria resulted in a consensus conference in which corneal experts ultimately produced two reports, the first of which focuses on definition, classification, diagnosis, and staging of limbal stem cell deficiency.
The committee published a global consensus in Cornea (Deng et al. 2019;38:364-75). The second report on treatment guidelines is currently under review.
The new definition of limbal stem cell deficiency is that it is “an ocular surface disease caused by a decrease in the population and/or function of corneal epithelial stem/progenitor cells that leads to the inability to sustain normal homeostasis of the corneal epithelium.”
This scenario leads to the clinical picture of conjunctivalization (goblet cells on the ocular surface), signs of epithelial dysfunction or both that include epithelial abnormalities, superficial neovascularization, ocular surface inflammation, and scarring.
However, decreased vision, pain, and negatively impacted quality of life are the frequent results for patients.