Systemic Diseases and Glaucoma

Abstract

Although, the level of intraocular pressure (IOP) is presently the most important and only modifiable risk factor in the development and progression of open-angle glaucoma, disease progression in many patients may occur with average IOP while others with ocular hypertension never develop glaucoma. Clearly then, non-pressure-related factors are playing an important role in modifying risk of disease progression. While the Ocular Hypertension Treatment Study (OHTS) served to identify age and central corneal thickness in addition to IOP as important factors in determination of risk to glaucomatous progression, the association between nonocular systemic factors and glaucoma has been controversial. Perplexingly, data from the OHTS in fact, found that having diabetes was “protective” of progression to glaucoma. Confounding the relationship between glaucoma and systemic disease is the fact that prevalence of glaucoma and systemic diseases such as cardiovascular disease and hypertension, diabetes, and thyroid dysfunction also increase with age. What then is the relationship between various systemic disease conditions and open-angle glaucoma risk and are there shared pathogenetic mechanisms involved? The relationship between various systemic disorders and glaucomatous nerve damage is intriguing and has been studied for the last three decades.