Causal relationship between ankylosing spondylitis and ocular inflammatory diseases: a Mendelian randomization study

Area of Science:

• Ophthalmology
• Rheumatology
• Genetics

Background:

• Observational studies suggest a link between ankylosing spondylitis (AS) and ocular inflammatory diseases.
• The precise genetically predicted association between AS and these conditions requires further investigation.

Purpose of the Study:

• To systematically assess the causal relationship between AS and various ocular inflammatory diseases using a Mendelian randomization approach.
• To clarify the genetic predisposition of AS patients to developing specific eye conditions.

Main Methods:

• A two-sample Mendelian randomization (MR) analysis was performed using genome-wide association study (GWAS) data.
• Multiple statistical methods including IVW, MR-Egger, and weighted median were employed.
• Sensitivity analyses were conducted to ensure the robustness of the findings, utilizing MR-PRESSO and Cochran's Q test.

Main Results:

• Genetically predicted AS showed a significantly increased risk for uveitis (OR=2.825), iridocyclitis (OR=3.806), scleritis (OR=1.738), and episcleritis (OR=5.113).
• No significant correlation was found between genetically predicted AS and keratitis or optic neuritis.
• The findings were consistent across various sensitivity analyses.

Conclusions:

• Ankylosing spondylitis is causally associated with an increased genetic risk for uveitis, iridocyclitis, scleritis, and episcleritis.
• The study did not find evidence for a causal link between AS and keratitis or optic neuritis.
• These findings may inform strategies for preventing ocular complications in patients with AS.