The value of Rose Bengal as a screening aid to diagnosis of conjunctival xerosis

Abstract

The present paper was designed to demonstrate the value of Rose Bengal in the diagnosis of conjunctival xerosis and at the same time determine the prevalence of ocular lesions due to vitamin A deficiency. A representative sample (501 children) between 3 and 6 years of age drawn from the population of the city of Cotia, SP, Brazil, was studied. Ocular examinations with and without the aid of Rose Bengal were performed on the 501 children. Those that presented positive results were submitted to a therapeutic test (200.000 IU of vitamin A orally). Whenever necessary corneae were examined with fluorescein. Vitamin A blood levels were determined by the Carr-Price method. No lesions beyond conjunctival xerosis were found. Examinations performed without the aid of Rose Bengal rendered 10.0% positive results whereas Rose Bengal tests rendered 18.2% positive results. Therapeutic tests showed low sensitivity and low specificity for the examinations without Rose Bengal (18.5% and 14.3%, respectively) and high sensitivity and specificity for examinations performed with Rose Bengal (81.5% and 89.0%, respectively). Based on our results the ocular examinations without the aid of Rose Bengal are not recommended for screening tests, whereas those performed with Rose Bengal are.