Metabolic syndrome as a risk factor in normal-tension glaucoma

To determine whether normal-tension glaucoma (NTG) is associated with metabolic syndrome and to evaluate which components of metabolic syndrome are related to NTG.

This study included 18240 participants who underwent health check-ups including fundus photography and intraocular pressure measurements. For NTG diagnosis, all participants with findings suggestive of glaucoma completed a further glaucoma evaluation, including applanation tonometry, gonioscopy and standard automated perimetry. The National Cholesterol Education Program Adult Treatment Panel III guideline was used to characterize metabolic syndrome.

Of the 18240 participants, 3635 (19.9%) had metabolic syndrome and 300 (1.6%) were diagnosed with NTG. The prevalence of NTG was 1.5% in subjects without metabolic syndrome and 2.1% in subjects with metabolic syndrome. The presence of metabolic syndrome was not significantly associated with NTG (p = 0.067). There were significant associations of NTG with hypertension and impaired glucose tolerance (IGT) among the individual components of metabolic syndrome (OR, 1.53; 95% CI, 1.20-1.94; p = 0.001 and OR, 1.47; 95% CI, 1.12-1.94; p = 0.006). NTG was positively associated with the number of metabolic syndrome components (OR, 1.10; p = 0.040). Multivariable analysis showed the prevalence of NTG to be significantly higher in participants aged between 50 and 70 years relative to those aged 40 to 50 years, male gender, participants with higher baseline intraocular pressure, hypertension and IGT.

Of the metabolic syndrome components, hypertension and IGT contributed to an increased risk of NTG. These findings suggest that metabolic syndrome components may play a role in the pathogenesis of NTG.