Surgical Management of Pterygium Invading the Corneal Flap Following Laser In Situ Keratomileusis: A Case Series

Pterygium is a benign fibrovascular growth that may invade the cornea and cause irregular astigmatism or visual disturbance. Surgical excision with conjunctival autografting is the standard treatment to prevent recurrence. However, the management of pterygium extending into the corneal flap after laser in situ keratomileusis (LASIK) is rarely reported and presents unique challenges due to the risk of flap-related complications. We report four cases of pterygium excision with conjunctival flap grafting for pterygium invasion of the corneal flap following LASIK treatment. This case series included four eyes of four patients (three men and one woman; mean age: 52.8±5.1 years) who received treatment at Nihon University Itabashi Hospital between November 2021 and February 2025. All patients underwent pterygium excision and conjunctival flap transplantation for the pterygium extending beneath the LASIK flap. The pre- and postoperative visual acuity, corneal astigmatism, and higher-order aberrations (HOAs) were measured using anterior segment optical coherence tomography (AS-OCT; CASIA 2, Tomey, Aichi, Japan). The mean follow-up period was 12.48±16.06 months. None of the patients experienced intra- or postoperative complications. The mean corrected logMAR visual acuity remained stable from baseline (-0.15±0.04) to the final visit (-0.15±0.04). The mean corneal astigmatism decreased from 3.33±2.54 D to 1.08±0.32 D (p=0.25). Anterior corneal HOAs (6 mm) improved from 3.21±2.38 μm to 0.99±0.23 μm (p=0.125). Posterior corneal HOAs (6 mm) were largely stable, changing from 0.22±0.11 μm to 0.12±0.02 μm (p=0.11). In conclusion, pterygium excision with conjunctival flap grafting is a safe and effective treatment for pterygia invading the LASIK flap. To prevent flap displacement and other complications, it is crucial to take special care to avoid tension on the LASIK flap during surgery.