Exposure keratopathy

ophthalmology

1. EXPOSURE KERATOPATHY BY ALBERT CHELANGA OCO/CS 6 th july , 2015.

2. Exposure keratopathy In exposure keratopathy , there is failure of the lids’ normal wetting mechanism , due to disease process that limit eyelids closure. Leads to consequent drying and damage to the corneal epithelium.

3. Causes of exposure keratopathy VII cranial nerve palsy – Idiopathic (Bell’s palsy) Stroke Tumor (e.g., acoustic neuroma , meningioma , choleastoma , parotid, nasopharyngeal) Demyelination Sarcoidosis Trauma (temporal bone fracture) Surgical section Otitis Ramsay Hunt syndrome (Herpes zoster) Guillan–Barre syndrome Lyme disease

4. Lid abnormality Nocturnal lagophthalmos Ectropion Traumatic defect in lid margin Surgical (e.g., overcorrection of ptosis ) Floppy eyelid syndrome. Orbital disease Proptosis Thyroid eye disease

5. Clinical features Irritable , red eye(s); may be worse in the mornings. Foreign body sensations. Photophobia. Tearing. Punctate epithelial erosions; usually inferior if underlying lagophthalmos . central if due to proptosis . Larger defects- opportunistic microbial keratitis ;- perforation. Corneal anaesthesia if there is neurotrophic component.

6. PHYSICAL EXAM • External examination may demonstrate: - Failure of lids to close fully on blink or voluntary closure ( lagophthalmos ). - Decreased frequency of blink. -Widened palpebral fissure. - Ectropion or lid position abnormalities. - Brow ptosis (in cases of facial nerve paralysis).

7. Treatment A dequate lubrication: consider high frequency or high viscosity- preservative-free preparations - preferred if >6x/day . Ensure adequate lid closure : - Use temporary measures- taping of the lids at night . - Intermediate – - Temporary lateral/central tarsorrhaphy . - Botulinum toxin–induced ptosis . - Permanent surgical procedures e.g. - Permanent tarsorrhaphy for lagophthalmos ; - Orbital decompression if proptosis ). • Treat secondary microbial keratitis

8. Treatment Ct … If there is significant ulcerative thinning, consider admission, Globe protection e.g. Glasses by day, shield at night. Taping. Bandage contact lens , or Lamellar grafting .

9. Prevention • Assess corneal protective mechanisms: check corneal sensation, tear film , lid closure (CN VII), Bell’s phenomenon; correct where possible. • Warn patient of risk of corneal disease and that pain, photophobia, or reduced V/A requires urgent ophthalmic assessment.

10. DIFFERENTIAL DIAGNOSIS • Dry eye syndrome. • Sjogren's syndrome. • Neurotrophic keratopathy . • Medicamentosa . • Blepharitis .

11. References Oxford American Handbook of ophthalmology A Textbook Of Clinical Ophthalmology - 3rd Edition Fundamentals and Principles of Ophthalmology- section 2. -(2011-2012)