Glaucoma refers to a group of eye diseases that causes progressive damage to the optic nerve within the eye.It is usually caused due to an increase in the pressure inside the eye [Intra ocular pressure (IOP)].The optic nerve is the nerve responsible for vision, thus once it is damaged it would lead to gradual loss of vision and sometimes total blindness.
The pressure inside the eye is maintained by a fluid called aqueous humour.This fluid is produced inside the eye(these are not tears) and drains through fine channels. If these drainage channels are blocked or the eye produces too much of this fluid then the pressure of the eye rises.
Age : The risk of glaucoma rises >40 years of age.
Raised intraocular pressure(IOP)
Family History of Glaucoma
Conditions that affect, or are related to, blood flow: Diabetes, low blood pressure, and hypertension.
Extremes of refractive error : High/pathological myopia(associated with POAG) or Hypermetropia(associated with PACG)
Eye injuries or eye surgeries
Use of steroids(Topical /Oral /Inhalational etc)
Glaucoma is detected through a comprehensive eye examination that includes the following:
Visual acuity test : This eye chart test measures how well you see at various distances.
Tonometry : This is the measurement of pressure(intraocular pressure /IOP) inside the eye by using an instrument.
Gonioscopy : It is the visualization of the drainage angle of the eye which the doctor performs using an instrument.This helps to determine whether the angle is open or closed.
Dilated eye examination : In this examination , drops are given to dilate the pupil to visualize the optic nerve and the other structures inside the eye.
Visual field test : This test measures the peripheral (side vision). It helps to determine whether the patient has lost any peripheral vision which is an early sign of glaucoma.
OCT (Optical Coherence Tomography): This is a test to see the status of the optic nerve head and the thickness of the retinal nerve fiber layer within the eye.In glaucoma there is thinning of the retinal nerve fiber layer.
Pachymetry : This is the measurement of the thickness of the cornea.
Eye Drops ( Anti - Glaucoma medication) : These either reduce the formation of fluid in the eye or increase its outflow, thereby lowering eye pressure.
Surgical Procedures : (Trabeculectomy , Glaucoma Drainage Devices etc)