Herpes Simplex Keratitis

HSV keratitis (HSK) is a common severe corneal disease, the leading cause of corneal morbidity and blindness. Rising trend due to antibiotics/steroids; recurrent attacks threaten vision; no drug reliably prevents recurrence—worldwide leading cause of blindness.

Common Symptoms

Vesicle; ciliary injection; lacrimation; corneal ulcer; keratitis; crusting

Causes and Pathogenesis

HSV is highly infectious: 90% of adults are seropositive but only 1-10% have clinical disease. Primary infection only in non-immune children (6 months-5 years); virus then lifelong latent. Recurrence triggered by cold/fever/malaria/emotion/menses/UV/steroids/trauma. Nesbarn/Green cycle: (1) lytic/subclinical infection spreads from tears to cornea/conjunctiva/adnexa; (2) neural latency in trigeminal ganglion; (3) reactivation; (4) peripheral replication; (5) recurrent keratitis; (6) re-latency. Superficial = direct epithelial infection → dendritic → geographic keratitis. Deep = immune-mediated delayed hypersensitivity to HSV antigen (stromal/necrotizing keratitis). Risk factors: (1) cell-mediated immunity (low lymphocyte transformation/MIF in stromal HSK); (2) HLA (B4/DRw3/A3/B8/B27); (3) atopy (37% vs 10-15% normal).

Treatment

Drug therapy, supportive therapy

Preventive Measures

Prevent colds; avoid overwork; strict indications for steroids; lens hygiene. Viral keratitis now exceeds bacterial. Frequent antiviral drops + antibiotic prophylaxis. Do not abuse topical steroids during active ulceration (risk of perforation). Light nutritious diet; avoid spicy food.

Department to Visit

It is recommended to visit the Ophthalmology department; an appointment can be booked on this platform before the visit.

Warm reminder: The above information is for health science reference only and cannot replace professional medical diagnosis. If you have related symptoms, please seek medical attention at a regular hospital promptly.