SynthesisInvestigative ophthalmology & visual science2025
Climate Determinants of Keratoconus: Insights From a Systematic Review of Prevalence.
Synthesis in Investigative ophthalmology & visual science, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 4 papers.
What it found
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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
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Who cites it
4 citing papers in PubMed.
- Living Well with Keratoconus: Implications for Person-Centred Eye Care.Ophthalmic & physiological optics : the journal of the British College of Ophthalmic Opticians (Optometrists) · 2026Article
- Behavioral and Sociodemographic Factors Associated with Vision-Related Quality of Life in Keratoconus: A Cross-Sectional Study in Riyadh, Saudi Arabia.Vision (Basel, Switzerland) · 2026Article
- Article
- The Genetic and Epigenetic Architecture of Keratoconus: Emerging Pathways and Clinical Implications.Genes · 2026Review
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
9 authors.
Funding
No grant is acknowledged in the PubMed record.
Abstract
Purpose: The reported prevalence of keratoconus varies widely worldwide, but the causes of this variation are not well understood. We therefore aimed to explore the potential impact of local climate variables on keratoconus prevalence. Methods: The worldwide prevalence of clinical keratoconus in the general population was systematically reviewed. In each eligible prevalence area, four climate variables deemed possibly relevant to keratoconus were assessed: daily maximum temperature, relative humidity, ultraviolet radiation, and wind speed. Climate variables were calculated using worldwide gridded climate datasets from the European Center of Medium-Range Weather Forecasts. Population density weighting was applied to enhance exposure accuracy. The average of each climate variable was calculated over the 10 years preceding data collection of each study. The potential impact of those climate variables was investigated using multiple linear regression adjusted for the gross domestic product per capita (based on purchasing power parity) with the natural logarithm of prevalence as the outcome variable. Results: Sixteen eligible studies were identified. After filtering to retain one prevalence estimate per region, 11 studies including datapoints from 61 areas were analyzed. The median (interquartile range) prevalence of keratoconus was 0.10% (0.07%-0.19%). Multiple regression revealed a significant negative association between humidity and keratoconus prevalence (β = -0.03; 95% confidence interval, -0.06 to -0.01; P = 0.004). In contrast, the other analyzed climate variables were not significantly associated with keratoconus prevalence. Conclusions: Using global gridded climate maps, we observed a significant and biologically plausible link between low humidity and keratoconus. This suggests that humidification could benefit patients and at-risk groups.
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Registered trials
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