Dry and Wet Eye: Clinical and Histopathologic Characterization of an Ocular Surface Inflammation

Abstract

Abstract: : Purpose: Ocular surface inflammation (OSI) is a noninfectious superficial keratoconjunctivitis which frequently associated with photophobia and headache, forming a recently described Irritable Eye Syndrome (IES). Here we present, the first time, clinical characteristics and histopathologic features of the OSI. In addition, we also delineate subtypes of this disease, such as dry and wet eye. Methods: 142 patients affected by IES were selected from outpatients presented at our department (98 female and 44 male, mean age 52 years). Subjective symptoms and objective signs were evaluated by questioner and by ocular examinations, respectively. Diagnostic tests for tear secretion were also applied. In addition, in 35 cases biopsy were performed from the bulbar conjunctiva, and the specimens were studied by standard light and electron microscopic techniques. Results: Three clinical characteristics were observed: (i) subjective symptoms of ocular irritation, (ii) particular sensibility (hyperalgesia) to environmental influences, and (iii) abnormal secretion of tear fluid, mucus or lipids. These observations showed that irritation and hypersensitivity symptoms of OSI may be associated either with increased tear secretion (wet eye) or with decreased tear secretion (dry eye). Histopathology: besides leukocytic infiltration of the conjunctival substantia propria and epithelium, some of the epithelial cells (Type II or secondary secretory cells) showed characteristic granules of various electron-density in their cytoplasm. Both number and electron-density of these granules were correlated with the clinical forms of this disease. Conclusions: These clinical and histopathologic studies suggested that OSI may be considered as a spectrum of diseases, in which wet eye represents one end, while dry eye another end of the same spectrum. Pathophysiologic background for these forms of OSI will also be discussed.

Keywords: conjunctivitis • cornea: tears/tear film/dry eye • pathobiology