There are different types of glaucoma, which can be classified broadly as either open angle or narrow angle in nature. Both types result in damage occurring to the optic nerve or retinal nerve fibre layer causing progressive and sometimes sudden visual loss. Glaucoma has also been referred to as the ‘sneak thief of sight’ because often a patient will not know that they are losing vision due to glaucoma until it is in its more advanced stages.
Tests used to diagnose and monitor glaucoma include Intraocular pressure measurement, examination of the optic disc and ocular structures, visual field testing (perimetry) and OCT (ocular coherence topography) imaging of the optic disc and retinal layers. The visual field test gives the ophthalmologist a very detailed overview of the effect of glaucoma damage on the patient’s peripheral vision. It is an important test to enable early detection of peripheral vision loss and to allow treatment efficiency to be monitored. An example of a visual field test can be found through the link below. The OCT test provides details of the extent of structural damage to the eye and optic nerve. Examples of these tests are shown below.
Additional tests may also be undertaken on a case to case basis. A Water Drinking Test is an example of such a test. This test takes a minimum of 2 hours. It involves our team measuring your intraocular pressures regularly over a set period of time to determine the extent of fluctuation in your intraocular pressure due to the osmotic effect of consuming a set amount of water in a short duration of time.
The usual first line treatment for open angle glaucoma involves using eye drops, which need to be instilled into the eye regularly to lower their intra-ocular pressure and thus slow the progression of damage to the optic nerve.
Selective Laser Trabeculoplasty involves the ophthalmologist applying a specialised laser energy to the drainage tissue of the eye, to help improve fluid drainage from the eye and thus lower intra-ocular pressure.
Another treatment option involves injecting a small implantable drainage device into the trabecular meshwork. This can be a very effective method of lowering intra-ocular pressure and is usually undertaken at the time of cataract surgery.
In the case of narrow angle glaucoma, a laser procedure called laser peripheral iridotomy is normally used to create extra drainage channels for the aqueous fluid inside the eye to drain away and hence prevent or stop pressure from building up inside the eye. This treatment assists in preventing sudden loss of vision that may result as a consequence of acute glaucoma.