Systemic disease associations of familial and sporadic glaucoma: the Glaucoma Inheritance Study in Tasmania

Background: This aim of this study was to compare the prevalence of various disease-associated and potentially modifiable risk factors between people with familial and sporadic forms of primary open angle glaucoma (OAG).

Methods: A cross-sectional, retrospective study design was utilized. A detailed questionnaire enquiring about knowledge of family history, demographic data, current medications, and medical history of systemic disorders was administered. Where possible, living relatives were examined for signs of OAG.

Results: A total of 3,800 potential patients with OAG were identified, of whom 2062 were examined. One thousand twelve (59.5%) subjects were found to have familial OAG, and 688 (40.5%) subjects had no known or identified relative with OAG (sporadic glaucoma). One thousand forty-two unaffected family members examined. A past history of migraine was found more often with familial OAG (OR: 1.67 95% CI: 1.15-2.42). This effect was primarily driven by patients who had a first-degree relative also affected by OAG. Following adjustment for male gender and the age at review, the presence of atherosclerosis was also found to be more common in patients with familial glaucoma than in people with sporadic disease (OR: 1.42 95% CI: 1.05-1.92). No significant difference in the prevalence of hypertension, Raynaud's phenomenon, diabetes mellitus or thyroid disease was identified.

Conclusions: Patients with a known relative affected by OAG were statistically significantly more likely to have a past history for migraine or presence of atherosclerosis compared to people with no known affected relative. An understanding of such differences and systemic comorbidities will be useful for further work investigating the underlying molecular mechanisms of this disease.