Risk factors for normal tension glaucoma in a young population

Abstract

Introduction: To identify systemic and ocular risk factors associated with normal tension glaucoma (NTG) in a young Korean population. Methods: Retrospective, population based cross-sectional case-control study was performed. Between 2009 and 2010, among participants from 392 clusters representative of the Korean population from the Korea National Health and Nutrition Examination Survey (KNHANES) (n =17,901), subjects between 19 to 39 years of age were included. Participants had structured interviews, blood pressure measurement, blood sampling and other measurements. The ophthalmologic examination included autorefraction, applanation tonometry, slit lamp examination and fundus photography. For participants meeting the glaucoma suspicion criteria, frequency doubling perimetry testing with the screening program N-30-1 was performed. NTG was diagnosed using International Society of Geographical and Epidemiological Ophthalmology criteria. The systemic and ocular risk factors for NTG were analyzed using univariate and multivariate comparisons. Results: Eighty NTG patients and 4015 controls were included. In the univariate analysis, NTG group were more likely to have higher fasting plasma glucose (FPG) (98.04±33.16 vs. 89.74±12.65, p <0.001) and higher proportion of fasting capillary glucose (FCG) ≥200 mg/dL (p <0.001) than control. Multivariate analysis with logistic regression with stepwise selection of variables found that high myopia (OR, 3.54 [95% CI,1.34- 9.39], p=0.011), FCG≥200 mg/dL (OR, 12.65 [95% CI, 2.63, 60.94],p=0.002) and low high density lipoprotein cholesterol (HDL-C) (OR, 0.96 [95% CI, 0.94- 0.99],p=0.015) were associated with an increased risk of having NTG. Conclusions: High myopia, FCG level ≥200mmol/L and low HDL-C level were significant risk factors for NTG in a young Korean population.