Xerosis of conjunctiva
Xerosis of the conjunctiva is a symptomatic condition in which conjunctiva becomes dry and lustreless.
Normal conjunctiva is kept moist by its own secretions, mucin from goblet cells and aqueous solution from accessory lacrimal glands. Therefore, even if the main lacrimal gland is removed, xerosis does not occur.
Depending upon the etiology, conjunctival xerosis can be divided into two groups, parenchymatous and epithelial xerosis.
1. Parenchymatous xerosis.
It occurs following cicatricial disorganization of the conjunctiva due to local causes which can be in the form of
(i) widespread destructive interstitial conjunctivitis as seen in trachoma, diptheric membranous conjunctivitis, Steven-Johnsons syndrome, pemphigus or pemphigoid conjunctivitis, thermal, chemical or radiational burns of conjunctiva,
(ii) exposure of conjunctiva to air as seen in marked degree of proptosis, facial palsy, ectropion, lack of blinking (as in coma), and lagophthalmos due to symblepharon.
2. Epithelial xerosis.
It occurs due to hypovitaminosis -A. Epithelial xerosis may be seen in association with night blindness or as a part and parcel of the xerophthalmia (the term which is applied to all ocular manifestations of vitamin A deficiency which range from night blindness to keratomalacia.
Epithelial xerosis typically occurs in children and is characterized by varying degree of conjunctival thickening, wrinkling and pigmentation.
Treatment.
Treatment of conjunctival xerosis
consists of
(i) treatment of the cause, (ii)symptomatic local treatment with artificial tear preparations (0.7% methyl cellulose or 0.3% hypromellose or polyvinyl alcohol), which should be instilled frequently.
OPTOMETRY-SHARP VISION
Optometrist
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