If you suspect<unk>  then treat it! Diagnosis is clinical and difficult to confirm, treatment is simple/inexpensive/effective, there is little risk to treatment, and the risk of morbidity/mortality from not treating is high
Give thiamine BEFORE glucose in patients requiring glucose who are at risk for thiamine deficiency; glucose without thiamine can precipitate/worsen WE by driving thiamine intracellularly
Beriberi
Vitamin A deficiency
Chilblains
Vitamin B deficiencies
Trachoma
Vitamin B1 deficiency 
Chalazion
Scombroid