CLINICAL AND ELECTRON-MICROSCOPIC OBSERVATIONS OF THE CONJUNCTIVA OF ADULT PATIENTS WITH BITOT SPOTS

  • 1 January 1981
    • journal article
    • research article
    • Vol. 20  (5) , 632-643
Abstract
Three adult patients with Bitot''s spots of the conjunctiva were observed in the American Southwest; all were in good health without obvious cause for vitamin A deficiency. Serum vitamin A levels were below normal in 2; the 3rd patient was on replacement vitamin A therapy with resultant high serum levels. Serum .beta.-carotene levels were low in 2 and normal in 1. Schirmer test without anesthesia was low normal in 2 and with topical anesthesia was abnormal in all. After 8 wk of oral vitamin A therapy, the Schirmer test and Bitot''s spots showed little response. EM of Bitot''s spots showed changes characteristic of keratinizing squamous epithelium: absence of goblet cells, increased tonofibrils, flattening of intermediate cells, loss of superficial cell nuclei and a keratin layer. Light microscopy of the inferior cul-de-sac conjunctiva showed increased surface goblet cells in 2 and absence of such cells in the third; by EM the substructure of the majority of the goblet cell mucin granules had a reticulated appearance in which an electron-dense fibrillar network was present within the granule matrix. The non-mucin-containing epithelial cells of the inferior cul-de-sac for the most part appeared normal.

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