Virus particles and leukocytes in herpes simplex keratitis

Area of Science:

• Ophthalmology
• Virology
• Immunology

Background:

• Herpetic infections are a common cause of corneal disease, leading to scarring and vision impairment.
• Interstitial keratitis and chronic keratitis are significant complications of herpetic eye disease.
• Ultrastructural analysis provides detailed insights into corneal pathology.

Purpose of the Study:

• To investigate the ultrastructural findings in corneas affected by herpetic infections and scarring.
• To identify the presence of herpes virus-like particles in different forms of keratitis.
• To explore the role of immune responses in the pathogenesis of herpetic interstitial keratitis.

Main Methods:

• Ultrastructural analysis of nine corneal specimens obtained post-penetrating keratoplasty.
• Examination of corneas with a history of herpetic infections and scarring.
• Classification of keratitis into vascularized interstitial keratitis and chronic keratitis.

Main Results:

• Herpes virus-like particles were detected in the stroma of five corneas with interstitial keratitis.
• Corneas with virus particles showed lymphocytic infiltration and, in some cases, macrophages.
• Lymphocyte contact with keratocytes suggested a role for cell-mediated immunity in herpetic interstitial keratitis.
• Disciform keratitis cases were negative for virus particles and leukocytic infiltration.
• Retrocorneal ridges were hypothesized to originate from a granulomatous reaction.

Conclusions:

• Cell-mediated immunity likely plays a role in the pathogenesis of herpetic interstitial keratitis.
• The presence of viral particles correlates with specific inflammatory responses in the corneal stroma.
• Retrocorneal ridges may result from a stromal-Descemet membrane granulomatous reaction.