In modern ophthalmology, among the 20 different types of glaucoma, there are several main ones:
Open-angle glaucoma, in which the drainage system of the eye is not functioning but the angle of the anterior chamber of the eye is normal. It occurs in 90% of patients, develops gradually, and is often asymptomatic.
Angle-closure (narrow-angle) glaucoma, in which the angle between the iris and the cornea is significantly narrowed, making it difficult for fluid to drain from the eye. It develops rapidly with symptoms that may come on suddenly, in the form of an attack with loss of vision.
Normal IOP glaucoma, which occurs in 1 in 3 people with this disease and develops when IOP is normal or slightly elevated.
Congenital glaucoma, which occurs due to improper intrauterine formation of the drainage channels of the eye.
Ophthalmologists distinguish four stages of glaucoma – from initial, asymptomatic (I) to terminal with loss of visual function (IV). In the absence of treatment, the disease progresses, and symptoms appear, including visual impairment.