Vitamin A in experimental herpetic keratitis

Area of Science:

• Ophthalmology
• Virology
• Immunology

Background:

• Herpes simplex virus (HSV) keratitis is a significant cause of vision impairment.
• Corticosteroids are commonly used to manage HSV keratitis but can have side effects.
• Vitamin A plays a crucial role in immune function and epithelial health.

Purpose of the Study:

• To evaluate the efficacy and safety of systemic vitamin A palmitate in treating experimental HSV keratitis in rabbits receiving corticosteroid treatment.
• To determine if vitamin A influences viral shedding or antibody response in HSV keratitis.

Main Methods:

• Rabbits with experimental HSV keratitis were treated with systemic vitamin A palmitate at three dosage levels alongside corticosteroids.
• Clinical severity of keratitis, viral recovery, and antibody responses were assessed.
• Body weight changes were monitored as an indicator of systemic toxicity.

Main Results:

• High-dose vitamin A palmitate significantly reduced the severity of HSV keratitis compared to lower doses.
• No significant effect of vitamin A on virus recovery was observed.
• Systemic vitamin A administration led to substantial weight loss in both infected and uninfected rabbits.
• Corticosteroid treatment enhanced the antibody response to HSV, an effect not augmented by vitamin A.

Conclusions:

• Systemic vitamin A palmitate at high doses offers a slight benefit in managing HSV keratitis severity, likely due to enhanced epithelial healing.
• The systemic administration of vitamin A palmitate is associated with significant toxicity, including weight loss.
• Local application of vitamin A may provide similar therapeutic benefits with reduced systemic toxicity for HSV keratitis.