Exacerbation of Granular Corneal Dystrophy Type 2 After Small Incision Lenticule Extraction

PURPOSE: To report the outcome of unilateral small incision lenticule extraction (SMILE) in a patient with granular corneal dystrophy type 2 (GCD2). METHODS: Slit-lamp photography and Fourier domain optical coherence tomography were used to document the clinical course and appearance of the corneas in a patient with genetically determined GCD2 who underwent unilateral SMILE in the right eye. RESULTS: Slit-lamp examination of a 23-year-old woman revealed 2 faint opacities at the surgical interface approximately 2 months after the SMILE procedure had been performed on her right eye. Nine and 3 typical GCD2 deposits located immediately beneath the Bowman layer were observed in the right and left corneas, respectively. Over time, the deposits at the interface increased in size, density, and number in the right eye. Fourier domain optical coherence tomography performed 33 months after the SMILE procedure revealed deposits at the SMILE interface that were distinct from those located immediately beneath the Bowman layer. The severity of disease exacerbation was less in this patient than what is typically observed in others who have undergone laser-assisted in situ keratomileusis or photorefractive keratectomy. CONCLUSIONS: SMILE is contraindicated in patients with GCD2, as are other corneal refractive surgical procedures. This case highlights the importance of genetic testing before the performance of refractive corneal procedures—especially for patients with corneal opacities on preoperative slit-lamp examination or a family history of corneal disease compatible with that of a corneal dystrophy.