High-Altitude Residence And Keratoconus: A Scoping Review

Published 2026 - 44th Congress of the ESCRS

Reference: POCOR385 | Type: Poster | DOI: 10.82333/s8cb-e924

Authors: Raul H Plasencia Salini* ¹ , Aileen Arevalo ² , Justo Luis Noriega Martinez ³ , Silva Alejandro ⁴ , Simon Fung ⁵

¹Universidad de San Martín de Porres,Lima ,Peru;CorneaClinic ,Trujillo,Peru, ²Ophthalmology,New York Eye and Ear Infirmary of Mount Sinai,New York ,United States, ³CorneaClinic,Trujillo,Peru, ⁴Clinica La Luz ,Lima ,Peru, ⁵Ophthalmology,University of California San Francisco,San Francisco ,United States

Purpose

To evaluate the association between high-altitude residence and keratoconus (KC) burden and to assess its implications for the screening of refractive surgery candidates.

Setting

Scoping review of population-based and clinical studies evaluating keratoconus burden in populations residing at high-altitude regions.

Methods

A scoping review was conducted in accordance with PRISMA-ScR guidelines. MEDLINE, Web of Science, and Google Scholar were searched from database inception through February 1, 2026. Studies evaluating the burden of keratoconus among populations residing in high-altitude regions were included. Two independent reviewers performed study selection and data extraction.

Results

Six studies met the inclusion criteria. Overall, results indicate a higher burden of keratoconus in high-altitude regions. In Saudi Arabia, KC prevalence was highest in mountainous areas (0.0122%) and lowest along the coast (0.0014%). In the United States, the highest prevalence was reported in Colorado (0.51%; 95% CI, 0.49–0.52), a high-altitude state. An Israeli population study found KC incidence increased progressively with altitude, with significantly higher rates above 500 meters than at lower elevations (p < 0.05). Among refractive surgery candidates at high altitudes, prevalence was higher (8.6%–18.7%), and one retrospective study showed significantly higher rates in a high-altitude city compared with coastal regions (p < 0.0001).

Conclusions

High-altitude residence has been proposed as a potential factor influencing the burden of keratoconus, although evidence remains limited. While a definitive relationship cannot be established, the available literature suggests that geographic altitude should be considered in keratoconus screening and in the preoperative assessment of refractive surgery candidates living in high-altitude areas. Further well-designed, population-based studies using standardized diagnostic criteria are needed to better characterize this potential association and to clarify underlying mechanisms.