ABSTRACT
The pipette and the scraping methods for exfoliative cytology of the conjunctiva and cornea for keratinization were compared. Eskelung, Papanicolau, Giemsa and Mallory connective tissue stains were tried to demonstrate the keratinized cells. Using the scraping method and Mallory stain, among groups of 102 and 20normal individuals, one-half had 1 to 4 with an average of 2 keratinized cells. All 13 children from Leyte from 3 to 16 years old and two adults 23 and 41 years old, with complaints of night blindness and 20/20 visual acuity, with dryness and wrinkling of the conjunctiva with or without Bitots spots had hyperkeratinization of the corneae and all portions of the conjunctivae. These varied from 71 to 100 keratinized cells with an average of 82.2 anucleated and 12.5 nucleated. Bitots spots showed keratinization with hyperplasia of its deeper portions. Local instillation of vitamin A did not improve the night blindness nor change the gross appearance of the conjunctiva and cornea. There was however less keratinization in Bitots spots and the cells became less polygonalAmong 35 children of the slum area in Leveriza, Manila, 12 were found fairly nourished and 23 malnourished by the weight-height criterion of WHO. These two groups were examined by exfoliative cytology for conjunctival keratinization and for vitamin A content of the blood by the micro method of triflouroacetic acid. About half of them were also tested for night blindness by a color test designed at the Philippine Eye Research Institute. Only 2 of the 12 fairly nourished children had very slight keratinization above normal. Sixty-five percent of the malnourished children had slight to moderate hyperkeratinization of the conjunctiva. The vitamin A content of the serum was low in about 30 of them. Only one who was complaining of night blindness gave a negative color responseLocal and available foreign literature on the tests for ocular and systemic vitamin A deficiency and its manifestations, the metabolism of vitamin A, keratinization and vitamin A, genetics and the biological bases of medicine were reviewed to assess the meaning and implications of our observations. This is the first report on the microscopic conjunctival keratinization as a test for ocular and systemic hypovitaminosis A. Based on our findings and current medical and ophthalmological concepts, a classification of the manifestations of ocular hypovitaminosis A is made. The fundamental implications are discussed and concepts on the mechanism of conjunctival keratinization and Bitots spot formation in vitamin A deficiency are formulatedThe practical applications of microscopic conjunctival keratinization in ocular hypovitaminosis are enumerated. (Summary)