Abstract: Herpes simplex keratitis (HSK) is a recurrent viral infection of the cornea caused by the herpes simplex virus (HSV). This article aims to provide a comprehensive overview of HSK, encompassing its etiology, clinical manifestations, diagnostic methods, treatment strategies, and prognostic considerations.

Introduction: HSK is a leading cause of infectious corneal blindness worldwide, posing significant challenges in diagnosis and management. Given its recurrent nature and potential for sight-threatening complications, understanding the pathogenesis, clinical features, and therapeutic options is paramount in addressing this condition effectively.

Etiology and Risk Factors: HSK is primarily caused by HSV type 1 (HSV-1) and, less commonly, by HSV type 2 (HSV-2). The virus establishes latency in the trigeminal ganglion and can reactivate, leading to recurrent ocular inflammation. Risk factors for HSK include a history of herpetic infection, immunosuppression, ultraviolet (UV) light exposure, and ocular trauma. (Source: American Academy of Ophthalmology – Herpes Simplex Keratitis)

Clinical Presentation: HSK can manifest in various forms, including epithelial keratitis, stromal keratitis, and endothelial keratitis. Epithelial keratitis typically presents with dendritic or geographic corneal ulcers, associated with ocular pain, photophobia, and tearing. Stromal keratitis may result in corneal scarring, neovascularization, and decreased visual acuity, while endothelial involvement may lead to corneal edema and bullous keratopathy.

Diagnosis: Diagnosing HSK involves a comprehensive clinical examination, including slit-lamp biomicroscopy to assess corneal lesions and inflammatory signs. Fluorescein staining may reveal characteristic dendritic ulcers or geographic lesions. Additional tests such as viral culture, polymerase chain reaction (PCR), or serological assays may be performed to confirm HSV infection and differentiate HSK from other corneal diseases.

Treatment Strategies: Management of HSK aims to suppress viral replication, control ocular inflammation, and prevent recurrent episodes. Topical antiviral medications, such as trifluridine or acyclovir ointment, are commonly prescribed to treat epithelial keratitis. In cases of stromal or endothelial involvement, oral antiviral agents (e.g., acyclovir, valacyclovir) and topical corticosteroids may be added to the treatment regimen. (Source: American Academy of Ophthalmology – Herpes Simplex Keratitis Treatment)

Prognosis: The prognosis of HSK varies depending on factors such as the extent of corneal involvement, the presence of comorbidities, and the promptness of treatment initiation. While most cases of epithelial keratitis resolve with antiviral therapy, stromal or endothelial keratitis may result in long-term sequelae such as corneal scarring or vision loss. Early diagnosis, regular follow-up, and adherence to treatment are essential for optimizing visual outcomes and preventing recurrence.

Conclusion: In conclusion, HSK represents a significant ocular challenge characterized by recurrent viral keratitis and potential vision-threatening complications. Timely recognition, appropriate management, and patient education are essential in mitigating the impact of HSK and preserving ocular health. By advancing our understanding of its pathogenesis, refining diagnostic techniques, and exploring novel treatment modalities, we can enhance the management of HSK and improve patient outcomes.