Periocular Vitiligo in Keratoconus: A Case Report and Literature Review.

A 21-year-old Asian man developed asymmetrical keratoconus (OD > OS) in the context of right-sided periocular vitiligo. The patient was undergoing topical pimecrolimus treatment for his vitiligo, which caused periocular eye irritation, leading to aggressive, unilateral right-eye rubbing. Subsequently, he developed ocular symptoms such as eye strain-related headaches, aggravated by screen use. There was no relevant past medical history or family history of ocular disease. Corneal topography and keratography confirmed the diagnosis of keratoconus. The patient underwent femtosecond laser-assisted deep anterior lamellar keratoplasty (DALK) in the right eye and corneal cross-linking in the left eye to prevent progression. This case highlights a previously unreported association between periocular vitiligo, pimecrolimus-induced irritation, and subsequent keratoconus. The pathophysiological mechanism is likely multifactorial, involving mechanical stress from chronic eye rubbing and potential alterations in corneal biomechanics due to inflammatory mediators. Given the high prevalence of keratoconus among young patients and the increasing use of topical immunomodulators, this case underscores the need for heightened clinical awareness regarding periocular drug-induced irritation as a modifiable risk factor. It reinforces the importance of patient education on the risks associated with habitual eye rubbing and the need for cautious prescribing of periocular irritants, particularly in individuals at risk for corneal ectatic disorders. To our knowledge, this is the first case report demonstrating that periocular creams with known ocular irritation side effects can exacerbate eye rubbing, which may contribute to the onset and progression of keratoconus. Further research is warranted to explore preventive strategies and alternative therapeutic approaches to mitigate ocular irritation and keratoconus progression.