Peripheral Nodulocystic Corneal Degeneration: a case report

Purpose Peripheral nodulocystic corneal degeneration (PNCD) is a rare and poorly understood corneal degeneration. We report a case most consistent with PNCD in a patient with a remote history of conventional laser-assisted in situ keratomileusis (LASIK) and multiple systemic inflammatory conditions. Observation A 52-year-old woman with a medical history of multiple systemic arthralgias and an ocular history of bilateral LASIK presented with progressive left eye dryness and discomfort. Ocular examination revealed multiple bullous corneal nodules in both eyes, predominantly in the superior and temporal periphery of the cornea. Anterior segment optical coherence tomography (AS-OCT) revealed subepithelial cystoid spaces with Bowman’s Membrane disruption, and specular microscopy showed mild endothelial cell loss with polymegethism and pleomorphism. The clinical findings were most consistent with peripheral nodulocystic degeneration (PNCD). She declined superficial keratectomy, and her symptoms improved with topical cyclosporine, perfluorohexyloctane, and brimonidine. Conclusion and Importance We describe a case of lucent peripheral corneal bullae most consistent with PNCD, of which only one similar case has been previously reported in the literature. PNCD appears to be an indolent, slowly progressive corneal degeneration. This case highlights a unique presentation of corneal degeneration and cause of peripheral corneal bullae. The interplay between corneal degeneration, systemic inflammatory disease, and prior refractive surgery warrants further investigation.