Abstract
Purpose: :
Understanding risk factors in relation to disease is important for both diagnosis and treatment. In glaucoma, several risk factors have been identified however the literature is at times conflicting, suggesting further study of this topic to be of value. This study was designed to describe the presence and distribution of risk factors in Canadian patients with newly diagnosed ocular hypertension (OH) and open-angle glaucoma (OAG).
Methods: :
Subjects with newly diagnosed OH or OAG and not receiving ocular hypotensive therapy were enrolled following informed consent. Subjects underwent a complete medical history and ocular examination with results recorded on standardized data collection sheets. Descriptive statistics of all variables for the two diseases (OH and OAG) were calculated. In order to assess which risk factors and/or ocular variables were associated with OAG versus OH, adjusted odds ratios (OR), along with 95% confidence intervals (CIs), were obtained from multiple logistic regression models.
Results: :
405 subjects were included, 292 (72.1%) with OAG (202 primary, 65 normal tension, 16 pseudoexfoliation, 9 pigmentary glaucoma) and 113 (27.9%) with OH. The majority of subjects were Caucasian (348/405; 85.9%). The results of multiple logistic regression found that the odds ratio for OAG compared to OH was 8.19 (95% CI: 2.93-22.88; p<0.0001) for optic disc notch, 5.36 (95% CI: 2.12-13.56; p<0.001) for abnormal VF, 1.45 (95% CI: 1.17-1.80; p=0.001) for every one dB unit worsening of mean deviation, 1.91 (95% CI: 1.54-2.37; p<0.0001) for every 0.1 unit increase of cup-to-disc ratio, 1.03 for increased yearly age (95% CI:1.00-1.06; p=0.030), 0.36 (95% CI: 0.17-0.78; p=0.010) for smoking, and 0.27 (95% CI: 0.11,0.63; p=0.003) for location (Quebec/Atlantic vs Ontario).
Conclusions: :
The OAG subjects were more likely to have abnormal optic disc features and VF indices. Increased age was a risk for OAG when compared to OH whereas in this study, smoking and living in Quebec or Atlantic Canada compared to Ontario decreased the risk of OAG when compared to OH.
Keywords: clinical (human) or epidemiologic studies: risk factor assessment • clinical (human) or epidemiologic studies: health care delivery/economics/manpower • clinical (human) or epidemiologic studies: biostatistics/epidemiology methodology