Xerophthalmia refers to a spectrum of ocular pathology resulting from severe vitamin A deficiency. Xerophthalmia remains a major cause of preventable blindness in developing countries. The World Health Organization’s Classification of Vitamin A Deficiency is based on clinical features seen during comprehensive ophthalmic exam. (See Table 13.7.1.)
TABLE 13.7.1: World Health Organization Classification of Vitamin A Deficiency
| XN | Night Blindness |
|---|---|
| X1A | Conjunctival xerosis |
| X1B | Bitôt spot |
| X2 | Corneal xerosis |
| X3A | Corneal ulceration or keratomalacia with less than one-third corneal involvement |
| X3B | Corneal ulceration or keratomalacia with one-third or more corneal involvement |
| XS | Corneal scar |
| XF | Xerophthalmia fundus |
Night blindness (earliest and most common manifestation), dry eyes, ocular pain, and severe vision loss.
Bitôt spots (triangular, perilimbal, gray, foamy plaques of keratinized conjunctival debris); decreased tear break-up time; conjunctival and corneal xerosis (bilateral conjunctival and corneal dryness); corneal epithelial defects, sterile or infectious ulceration (often peripheral with a punched-out appearance), perforation, or scarring; keratomalacia (often preceded by a gastrointestinal, respiratory, or measles infection); fundus abnormalities (yellow or white peripheral retinal dots representing focal retinal pigment epithelium [RPE] defects).
Growth retardation in children; dry, hyperkeratotic skin; increased susceptibility to infections.
Other vitamin deficiency (Bitôt spots can be seen in niacin deficiency). See 4.3, Dry Eye Syndrome and 11.28, Retinitis Pigmentosa and Inherited Chorioretinal Dystrophies.
Primary: Dietary deficiency or chronic alcoholism (relatively uncommon in developed countries). Beyond 6 months postpartum, breast milk in vitamin A–deficient mothers is unlikely to sufficiently maintain vitamin A stores in nursing infants.
Secondary: Lipid malabsorption (e.g., cystic fibrosis, chronic pancreatitis, inflammatory bowel disease, celiac sprue, postgastrectomy or postintestinal bypass surgery, chronic liver disease, abetalipoproteinemia [Bassen–Kornzweig syndrome]).
History: Malnutrition? Poor diet? Restrictive diet in an autistic patient? Alcohol use? Gastrointestinal or liver disease? Previous gastrointestinal surgery? Measles?
Complete ophthalmic examination, including careful inspection of eyelid margins and inferior fornices.
A positive response to treatment is a simple, cost-effective way to confirm the diagnosis.
Consider serum vitamin A level before treatment is initiated. These levels may appear normal due to the maintenance of circulating retinol by hepatic stores. Keep in mind that other vitamin deficiencies may coexist and may warrant testing.
Consider impression cytology of the conjunctiva, looking for decreased goblet cell density.
Consider dark adaptation studies and electroretinogram (may be more sensitive than the serum vitamin A level).
Corneal cultures if infection suspected. See Appendix 8, Corneal Culture Procedure.
Immediate vitamin A replacement therapy orally (preferred) or intramuscularly in the following WHO-recommended dosages for clinical xerophthalmia:
Children <12 months: 100,000 IU daily for 2 days, repeat in 2 to 4 weeks.
Adults and children >12 months: 200,000 IU daily for 2 days, repeat in 2 to 4 weeks.
Women of childbearing age (reduce dose due to possible teratogenic effects): Night blindness or Bitôt spots only, 10,000 IU daily for 2 weeks or 25,000 IU weekly for 4 weeks.
Intensive ocular lubrication with preservative-free artificial tears every 15 to 60 minutes and preservative-free artificial tear ointment q.h.s.
Consider supplementing the patient’s diet with zinc, vitamin A, and any other vitamins identified as deficient during workup.
Consider corneal surgery (e.g., penetrating keratoplasty or keratoprosthesis) for corneal scars in eyes with potentially good vision.
Prophylaxis with routine oral supplementation in endemic regions: