Open-angle glaucoma (also primary chronic glaucoma) is one of the most common forms of glaucoma, making up about 90% of all cases. It means that the angle where the iris meets the cornea is at normal width. Open-angle glaucoma is caused by increased eye pressure that is caused by clogging of the drainage canals.
It develops slowly and is often asymptomatic until some vision loss occurs. It is a lifelong condition, but early treatment can avoid vision loss. Some risk factors are elevated intraocular pressure, low central corneal thickness, female gender, history of migraines, older age, family history, African ancestry, myopia, and some diseases such as diabetes or hypertension.
It has been shown that smoking also contributes to the risk of developing glaucoma, because it has an overall negative impact on health. Also, genetic and environmental factors and their interactions are important for developing glaucoma. There have been identified two major genes that contribute the disease. Treatment usually involves lowering intraocular pressure with eye drops or oral medications.