Beyond Vision: Unveiling the Psychiatric Dimensions of Keratoconus

Background and Objectives: Keratoconus (KC) is a progressive corneal ectasia with multifactorial etiology, increasingly studied for potential associations with psychiatric disorders. This systematic review aimed to evaluate recent evidence linking KC with depression and other psychiatric conditions, including psychotic disorders, personality disorders, attention deficit hyperactivity disorder (ADHD), Tourette syndrome (TS), autism spectrum disorder (ASD), and obsessive-compulsive disorder (OCD). Materials and Methods: Following PRISMA guidelines, PubMed, ScienceDirect and SpringerLink were searched for English-language observational studies published since 2015 that examined psychiatric disorders in adults with keratoconus. We excluded reviews, case reports, pediatric, non-English, and inaccessible articles. Study quality was assessed using the Newcastle-Ottawa Scale and JBI Checklist. Data were narratively summarized and tabulated-without meta-analysis due to heterogeneity. Results: Twelve studies met inclusion criteria, including 41,906 KC patients and 63,267 controls. Eleven studies investigated depression and one ADHD. Findings on depression were mixed: five studies showed higher depressive symptoms among KC patients, while others found no significant association. Most were cross-sectional and of moderate-to-high quality. The single study on ADHD reported a higher prevalence of KC in males, but no evidence of casual association. Evidence on TS, ASD, and OCD was scarce and largely limited to case reports. The review was limited by heterogeneous methodologies, small sample sizes, an absence of longitudinal data, and reliance on self-report or registry data. Conclusions: Current evidence indicates increased psychological burden among some individuals with KC, particularly regarding depressive symptoms, yet casual relationships remain unproven. Male ADHD patients may have an elevated risk of KC, especially in the presence of eye rubbing. Registration: Not registered.