tailieunhanh - Chapter 029. Disorders of the Eye (Part 7)

Allergic Conjunctivitis This condition is extremely common and often mistaken for infectious conjunctivitis. Itching, redness, and epiphora are typical. The palpebral conjunctiva may become hypertropic with giant excrescences called cobblestone papillae. Irritation from contact lenses or any chronic foreign body can also induce formation of cobblestone papillae. Atopic conjunctivitis occurs in subjects with atopic dermatitis or asthma. Symptoms caused by allergic conjunctivitis can be alleviated with cold compresses, topical vasoconstrictors, antihistamines, and mast cell stabilizers such as cromolyn sodium. Topical glucocorticoid solutions provide dramatic relief of immune-mediated forms of conjunctivitis, but their long-term use is ill-advised because of the. | Chapter 029. Disorders of the Eye Part 7 Allergic Conjunctivitis This condition is extremely common and often mistaken for infectious conjunctivitis. Itching redness and epiphora are typical. The palpebral conjunctiva may become hypertropic with giant excrescences called cobblestone papillae. Irritation from contact lenses or any chronic foreign body can also induce formation of cobblestone papillae. Atopic conjunctivitis occurs in subjects with atopic dermatitis or asthma. Symptoms caused by allergic conjunctivitis can be alleviated with cold compresses topical vasoconstrictors antihistamines and mast cell stabilizers such as cromolyn sodium. Topical glucocorticoid solutions provide dramatic relief of immune-mediated forms of conjunctivitis but their long-term use is ill-advised because of the complications of glaucoma cataract and secondary infection. Topical nonsteroidal anti-inflammatory agents NSAIDs such as ketorolac tromethamine are a better alternative. Keratoconjunctivitis Sicca Also known as dry eye it produces a burning foreign-body sensation injection and photophobia. In mild cases the eye appears surprisingly normal but tear production measured by wetting of a filter paper Schirmer strip is deficient. A variety of systemic drugs including antihistaminic anticholinergic and psychotropic medications result in dry eye by reducing lacrimal secretion. Disorders that involve the lacrimal gland directly such as sarcoidosis or Sjogren s syndrome also cause dry eye. Patients may develop dry eye after radiation therapy if the treatment field includes the orbits. Problems with ocular drying are also common after lesions affecting cranial nerves V or VII. Corneal anesthesia is particularly dangerous because the absence of a normal blink reflex exposes the cornea to injury without pain to warn the patient. Dry eye is managed by frequent and liberal application of artificial tears and ocular lubricants. In severe cases the tear puncta can be plugged or cauterized to