Ocular Surface Disorders in Hajj Pilgrims: A Systematic Review of Environmental Exposure and Travel-Related Health Risks
Abstract
Purpose: Hajj pilgrimage represents a unique mass gathering environment where pilgrims are exposed to extreme climatic conditions and travel-related health risks. While previous Hajj health research has primarily focused on infectious diseases and acute medical conditions, ocular surface disorders remain insufficiently explored. This systematic review aims to synthesize current evidence regarding ocular surface disorders associated with environmental exposure and travel-related health risks among Hajj pilgrims and comparable arid environmental settings. Methods: This systematic review was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 guidelines. Literature searches were performed in Scopus, PubMed/MEDLINE, Web of Science, and Embase for studies published from January 2015 to August 2026. Original research articles evaluating ocular surface outcomes, dry eye disease, and environmental or travel-related risk factors were included. Review articles, editorials, conference abstracts, and studies without primary data were excluded. After screening and eligibility assessment, five primary studies were included in the qualitative synthesis. Main Findings: The included studies demonstrated that environmental stressors associated with arid climates, including high temperature, low humidity, sunlight exposure, dust, air pollution, and air-conditioning exposure, are important contributors to ocular surface instability and dry eye symptoms