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neu·ro·tro·phic ker·a·ti·tis(nūr'ō-trō'fik ker'ă-tī'tis)
Synonym(s): neuroparalytic keratitis.
keratitis(ker-a-tit'is) [ kerato- + -itis]
It is often caused by contact lenses, but it may also result from drugs, microorganisms, immunodeficiency, trauma, or vitamin A deficiency.
Therapy depends upon the underlying cause. Bacterial infections respond to antibacterial medications (typically administered in drops); herpes simplex viral infection requires antiviral agents; fungal keratitis is treated with antifungal agents; exposure keratitis, as in Bell's palsy, is preventable with topical lubricants.
Because of the seriousness of keratitis, patients experiencing eye inflammation or pain should seek immediate medical attention. The patient is assessed for a history of recent upper respiratory infection accompanied by cold sores, pain, central vision loss, the sensation of a foreign body in the eye, contact lens use, photophobia, and blurred vision. The eye is inspected for loss of normal corneal luster and inflammation. A slit lamp examination is often used for optimal viewing of the eye to confirm the condition. Fluorescein staining helps determine the extent and depth of corneal ulcerations. The patient should refrain from rubbing the eye, which can cause complications. Prescribed therapies are administered, and the patient is instructed in their use. Warm compresses are applied as prescribed to relieve pain. If the patient complains of photophobia, the use of dim lighting or sunglasses is recommended. The patient should follow the prescribed treatment regimen carefully for the entire course and return for follow-up examination.
Patient education: the correct instillation of prescribed eye medications and the importance of thorough handwashing before and after touching the eye are emphasized. Contact lenses are removed and are not replaced until infectious forms of keratitis are cured. Any potentially contaminated lenses or lens solutions should be discarded. Stress, traumatic injury, fever, colds, and overexposure to the sun may trigger flare-ups. Both patient and family are taught about safety precautions pertaining to visual sensory or perceptual alterations. They are encouraged to verbalize their fears and concerns. Appropriate information and emotional support and reassurance are provided.
CAUTION!Because many common forms of keratitis are infectious, examiners should use standard precautions during the evaluation of the eye.
neurotrophic keratitisNeuroparalytic keratitis.
parenchymatous keratitisInterstitial keratitis.
superficial punctate keratitisPunctate keratitis See: Thygeson disease
actinic keratopathy A form of corneal degeneration characterized by white or yellowish stromal deposits consisting of cholesterol, fats and phospholipids, and in some cases corneal vascularization. The condition may be caused by exposure to sunlight (especially ultraviolet radiations) or trauma. The deposits are usually present within the pupillary area, often as elevated nodules distributed in a band-shaped configuration, and can have a dramatic effect on visual function. The damage is similar to that found in pterygium and pinguecula. Treatment consists of resorbing the lipid infiltrates and, in severe cases, keratoplasty. Syn. Bietti's band-shaped nodular dystrophy; climatic droplet keratopathy; Labrador keratopathy; lipid droplet degeneration.
band keratopathy A disorder characterized by the deposition of calcium salts in the anterior layers of the cornea, such as the basement membrane, Bowman's layer and the anterior stromal lamellae. They appear as opacities forming a more or less horizontal band with clear holes within the band giving it a Swiss cheese appearance. The causes may be systemic (e.g. hypercalcaemia, familial, old age, chronic renal failure) or ocular (e.g. chronic anterior uveitis, interstitial keratitis, silicone oil in the anterior chamber, phthisis bulbi). It is commonly associated with juvenile idiopathic arthritis and sarcoidosis. Symptoms include irritation and blurring of vision. Treatment may be necessary for cosmetic or visual reasons. It consists of removal of the calcium salts by scraping the corneal epithelium followed by irrigation with EDTA, or laser keratectomy. Syn. band-shaped corneal dystrophy. See juvenile idiopathic arthritis; ethylenediamine tetraacetic acid (EDTA).
bullous keratopathy Degenerative condition of the cornea characterized by the formation of epithelial blebs or bullae, which burst after a few days. This condition may follow cataract surgery, corneal trauma, severe corneal oedema, glaucoma, iridocyclitis, etc. Soft contact lenses have often been found useful to relieve pain in this condition by protecting the denuded nerve endings. See cornea guttata; Fuchs' endothelial dystrophy; therapeutic soft contact lens.
climatic droplet keratopathy; Labrador keratopathy See actinic keratopathy.
exposure keratopathy A disorder caused by the failure of the eyelids to cover the globe, resulting in improper wetting of the ocular surface by the tears with consequent desiccation of the corneal epithelium. This condition may be caused by facial nerve disorders in which the orbicularis oculi muscle is paralysed, or sleep lagophthalmos, or as a result of hard contact lens wear. The cornea presents punctate epithelial erosions, which may develop, into ulcers. Treatment is with frequent lubrication and if severe, lid surgery may be required. Syn. lagophthalmic keratitis; neuroparalytic keratopathy. See neuroparalytic keratitis; 3 and 9 o'clock staining.
neurotrophic keratopathy Condition characterized by an anaesthesia of the cornea. It results in a breakdown of the corneal epithelial layer allowing trauma, desiccation and infection. It is believed to occur as a result of the loss of trophic influence of the nerve supply to the cornea and/or of reduced blinking and the loss of lacrimation. Causes include herpes simplex virus, herpes zoster, lattice dystrophy, fifth nerve lesion and diabetes mellitus. Treatment mainly consists of tear substitute and intermittent or constant lid taping, but anti-infective regimen, punctal occlusion, tarsorrhaphy or neurosurgical intervention may be necessary. Syn. neurotrophic keratitis.