Introduction: Granular Corneal Dystrophy Type 2 (GCD2), also known as Avellino Corneal Dystrophy, is an autosomal dominant disease that affects approximately 11.5 of 10,000 individuals and prevalence is especially high in the Korean population. Due to an Arg124His mutation in transforming growth factor β-induced gene, GCD2 presents clinically as a combination of granular and lattice dystrophies: superficial hyaline granular deposits in the anterior corneal stroma and occasionally amyloid lattice lesions in the deep stroma. When a stromal haze develops between these deposits, significant vision impairment can occur.
Case Report: A 77-year old Korean male was initially seen by the USC Roski Eye Institute Cornea Service and then referred to our Optometry Service for a contact lens fitting to avoid surgical intervention. OCT imaging revealed superficial and deep stromal deposits with haze between opacities characteristic of GCD2, suggesting the need for DALK if vision could not be improved. Ultimately, he was fit with a scleral lens in both eyes, and vision improved from 20/60-2 OD and 20/60-2 OS with spectacles to 20/30-2 OD and 20/40-2 OS with scleral lenses.
Discussion: Management and visual prognosis of GCD2 can be challenging depending on depth and size of the deposits. Surgical treatment options include PTK for superficial deposits and DALK or PKP for deeper deposits, though both have high risk for recurrence. Therefore, rigid gas permeable contact lenses can be a good alternative to mask the irregular astigmatism induced by these corneal opacities. Moreover, patients with GCD2 are at an increased risk for recurrent corneal erosions when Bowman’s layer is involved, so the use of scleral lenses can optimize corneal health while also providing an ideal spherical refractive surface.
Conclusion(s): Scleral contact lenses can be a great option for vision correction in patients with Granular Corneal Dystrophy Type 2 to avoid surgical intervention.