LAUSR

To the Editor: We read with great interest the article entitled “Global Consensus on Definition, Classification, Diagnosis, and Staging of Limbal Stem Cell Deficiency” by Deng et al.1 We consider this global consensus very helpful in clinical practice and for clinical research purposes. We acknowledge that classification of a disease with such a wide variety of causes is difficult and complex; however, we believe that the following causes should be considered. In the subgroup of acquired nonimmune-mediated LSCD, vitamin A deficiency is missing. Its role is important for corneal and conjunctival development and central nervous function. Although there are worldwide food fortification programs that have improved micronutrient malnutrition in nondeveloped countries,2 in developed countries, bariatric surgery is increasingly used as a treatment for obesity. As a result of that procedure, an absence of regular substitution of macro and micronutrients can lead to vitamin A deficiency.3 Neurotrophic keratopathy, severe infectious keratitis, and cryotherapy are further causes of LSCD that have been reported and should be surveyed. Regarding acquired immunemediated LSCD, rosacea blepharoconjunctivitis and phlyctenular diseases also should be contemplated.4 In addition, there are congenital causes of LSCD to be considered, including sclerocornea and Turner syndrome.5