Types of Angle Closure Glaucoma
Types of Angle closure glaucoma can be according to the causes and according to the time of onset.
According to the causes
According to the causes it can be divided into primary and secondary angle closure glaucoma.
1- Primary Angle Closure Glaucoma
There are no pathological causes or diseases of the eye that will cause the angle to be closed. The anatomy of the eye is the predisposing factor for the angle to be closed.
2- Secondary Angle Closure Glaucoma
There are diseases and pathological causes in the eye which will lead to angle closure. Example of theses causes are diabetic mellitus which will form new blood vessels on the iris called Rubeosis.
Those new blood vessels will grow over the angle and form fibrovascular membrane. When this membrane contracts, it will pull the iris over the angle and close it causing angle closure glaucoma and in this case it is called neovascular glaucoma.
According to time of onset
According to the time of onset, it can be divided into acute angle glaucoma and chronic angle glaucoma.
1- Acute Angle Glaucoma
The angle will be completely closed suddenly by the iris and there will be sudden raise of IOP with severe pain and blurring of vision. As we said it is medical emergency because it can cause permanent damage to eye structures.
2- Chronic Angle Closure Glaucoma
In this type, the angle is not completely closed and there is still drainage of the aqueous humor but to a lesser extent than normal. The intraocular pressure will increase slowly and its symptoms are the same as POAG and the only difference is that the angle is opened in Primary Open Angle Glaucoma.