Bilateral Thygeson's Superficial Punctate Keratitis with Dendritic Corneal Lesion: A Case Report

Thygeson's superficial punctate keratitis (TSPK) is a recurrent bilateral corneal epithelial disease. Typically, small, multiple discrete epithelial lesions occur in the central cornea. However, dendritic corneal lesions are rare. Herein, we report a rare case of TSPK in both eyes after a unilateral dendritic corneal lesion. A 42-year-old woman presented with decreased vision and foreign body sensation in her right eye that persisted for 1 month. Her uncorrected visual acuity and best-corrected visual acuity (BCVA) were 20/160 in the right eye. Slit-lamp microscopy revealed a dendritic lesion in the central cornea of the right eye. No abnormalities were observed in her left eye. Herpetic keratitis in the right eye was diagnosed and systemic acyclovir was prescribed, along with topical acyclovir ointment and steroids. After one week, most of the corneal lesions had disappeared, and the BCVA in the right eye had improved to 20/25. The corneal epithelium completely recovered after 2 weeks. However, 2 weeks later, the patient visited the hospital with decreased visual acuity in the right eye, and the BCVA decreased to 20/40. Multiple fine corneal lesions were observed under a slit-lamp microscope. The patient was diagnosed with TSPK of the right eye. Topical steroids were started, and after 7 days, the corneal condition improved. However, after 6 weeks, visual acuity decreased in the left eye, and a corneal lesion similar to that in the right eye was observed; therefore, the patient was diagnosed with bilateral TSPK. Short-term topical steroids and long-term topical cyclosporine A 0.1% were used in both eyes, and the disease was maintained without recurrence for 3 months. TSPK can appear as a unilateral dendritic corneal lesion similar to herpetic keratitis. Therefore, in case of unilateral dendritic corneal lesions, it should be considered that TSPK may develop later.