Schnyder Corneal Dystrophy Or Another Mystery? Unraveling An Atypical Case Of Progressive Corneal Crystals

We present a complex case of a 42-year-old woman with persistent photophobia and progressive corneal changes who, following left pterygium left eye removal, was initially misdiagnosed with several conditions, including Salzmann’s nodular degeneration, before subsequent evaluations raised suspicions of Schnyder corneal dystrophy.

The patient was evaluated in a specialized ophthalmology outpatient setting with serial examinations performed from 2021 through 2025.

A comprehensive ophthalmologic evaluation was conducted, including slit-lamp examination with fluorescein staining, anterior segment optical coherence tomography (AS-OCT), and detailed laboratory tests to exclude systemic conditions such as hypercholesterolemia and hypercysteinemia. The patient was managed conservatively with artificial tears and maintained on regular follow-up, with genetic testing planned for diagnostic confirmation.

Initial findings in 2021 revealed bilateral mid-peripheral corneal whitening (3×2 mm) with positive fluorescein staining, leading to a preliminary diagnosis of Salzmann’s nodular degeneration. Despite symptomatic improvement with conservative management, the corneal lesions progressed over four years to display crystalline deposits following an arcus pattern. AS-OCT demonstrated increasing epithelial hyperreflectivity over time. Laboratory evaluations were unremarkable for metabolic disorders, prompting a revised diagnosis of suspected Schnyder corneal dystrophy despite the absence of familial history.

This case highlights the diagnostic complexity in corneal dystrophies with atypical presentations. Progressive corneal crystalline deposition and the development of an arcus pattern, despite initial management and negative systemic findings, underscore the importance of long-term monitoring and reconsideration of the diagnosis. Pending genetic testing, the evolving clinical features support a diagnosis of Schnyder corneal dystrophy, emphasizing the need for vigilance in similar cases.