Case Report: Antiviral treatment after pterygium surgery based on corneal confocal microscopy

Pterygium is a chronic inflammatory condition that commonly occurs on the bulbar conjunctiva of the nasal palpebral fissure. Its etiology is multifactorial, and surgical excision remains the primary treatment method. However, recurrence and other complications may affect treatment outcomes. Currently, the diagnosis and treatment of secondary corneal diseases following pterygium excision surgery vary. Therefore, in vivo confocal microscopy of the cornea holds significant clinical importance in clarifying the etiology of the disease.

An elderly diabetic patient presented with redness and swelling at the medial canthus of the eye and was diagnosed with recurrent pterygium. Following pterygium excision, follow-up examinations at 3, 10, and 20 days post-operation revealed a favorable prognosis. Approximately 1 month post-surgery, an anterior segment photograph of the eye showed an annular defect near the lateral limbus, which was considered to be "marginal keratitis". Treatment with immunosuppressive eye drops was initiated. After 3 days of medication proved ineffective, a follow-up consultation was sought. An anterior segment photograph with staining revealed a geographic superficial ulcer on the temporal side of the cornea, with no significant stromal infiltration. Through corneal confocal microscopy, a partial defect in the left eye's corneal epithelium was detected in the lesion zone. This was characterized by irregular, speckled, highly reflective spots and the presence of inflammatory cells. Additionally, there was a noticeable absence of subepithelial nerve fibers, along with activated Langerhans cells and stromal cells that were hyperactive in the periphery, exhibiting patchy and uneven deposits. Fortunately, the peripheral area displayed a sufficient number of endothelial cells. Following antiviral treatment, the patient's ocular condition improved.

Herpes simplex keratitis (HSK) is a rare but serious complication following pterygium surgery. This study confirms the evidence of secondary viral infection after pterygium surgery. In suspected cases, in addition to routine examination, conducting aetiological investigation is essential for early diagnosis and guiding treatment, thereby achieving a good visual prognosis.