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

Abstract

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.

Novel Manifestation of Corneal Dystrophy After Keratorefractive Surgery

“…They identified elongated basal epithelial cells, epithelial hyperplasia, epithelial basement membrane thickening and undulations, and Bowman layer undulations on the flap surface; they also observed activated keratocytes and eosinophilic deposits in the lamellar wound. Kwak et al 10 reported a patient with GCD2 with exacerbated corneal deposits after SMILE. They observed 2 distinct types of deposits, one at the interface and the other immediately beneath the Bowman layer or at the subepithelium.…”

“…These deposits were observed over a decade after the patients underwent keratorefractive surgery, resembling previously documented reports. 1,2,5,10 All 4 patients denied having a family history of ocular diseases and reported an uneventful postoperative course. In most corneal dystrophies, the deposits are centrally located in the cornea.…”

“…1,7,9 In the only case report after SMILE surgery, the deposits were located at the interface and immediately beneath the Bowman layer. 10 Herein, we report an unusual presentation of central corneal deposits in the Bowman layer in 4 patients after LASIK or RK surgery. The deposits exhibited unique firework patterns in the bilateral cornea, suggesting an underlying corneal dystrophy.…”

“…1,7,9 In the only case report after SMILE surgery, the deposits were located at the interface and immediately beneath the Bowman layer. 10…”

Corneal opacities after small-incision lenticule extraction

“…As the epithelium, which is not connected to the limbal epithelium directly, there would be limit for the continuation of the growth. If the debris are the ones with exacerbated granular corneal dystrophy type 2 after SMILE, the number and size of the deposits would increase with time 1 . In addition, the deposits would be located more at the central cornea.…”