Glaucoma
Glaucoma is one of the leading causes of irreversible blindness, aptly known as the “silent thief of sight” as patients commonly have no symptoms till the disease has progressed to an advanced stage. Treatment options are aimed at preserving existing vision and preventing further loss of vision.
Our eye is filled with a fluid called aqueous humour which is produced and gets drained at a constant rate maintaining the Intraocular pressure. In glaucoma the drainage pathway is closed or defective, leading to increased resistance to the outflow of fluid resulting in buildup of aqueous humour inside the eye causing an increase in eye pressure. This increased eye pressure affects the optic nerve of the eye leading to glaucomatous neuropathy or thinning of the nerve.
Risk factors for glaucoma are:
Age more than 40 years
Family history of glaucoma
Systemic diseases such as diabetes mellitus, hypertension, heart disease
Symptoms :
An acute attack of glaucoma can cause
pain
redness
blurring of vision and
halos
Most patients especially with open angle glaucoma experience no symptoms as the disease initially affects the peripheral or side vision only.
Very gradually it progresses to the centre. This is the reason why many people are not aware that they have the condition until they have significant vision loss affecting central vision.
Tests required :
If you have risk factors for developing glaucoma like age >40years, diabetes, high blood pressure, or a family history of glaucoma, you should consult your Ophthalmologist now to determine how often to have eye exams.
Glaucoma screening and work up :
TONOMETRY : checks the eye pressure
GONIOSCOPY : to determine if the angles are open or closed
FUNDUS : to check disk cupping
OCT : to determine if there any is thinning of optic nerve (neuro retinal rim)
PERIMETRY : to evaluate if your field of vision is affected. The data from this test is used to determine the severity of glaucoma and level of vision loss.
Medical Treatment
Your doctor will start by prescribing eye drops that will help decrease your eye pressure. This is either by improving fluid drainage from the eye or by decreasing the amount of fluid your eye makes. Depending on how low your eye pressure needs to be, more than one eye drop may be prescribed.
Some of these drops can cause mild irritation in the eyes, burning, redness or pigmentation.
Laser Peripheral Iridotomy (LPI)
Laser peripheral iridotomy is the preferred initial treatment in closed angle glaucoma or eyes at risk for this condition. In this procedure, the laser beam creates a hole in the colored part of the eye (iris) leading to an alternative pathway for the outflow of fluid.
Trabeculectomy
A small hole is made surgically in the coloured part of eye (Iris) which is guarded by a flap that acts as a trap door. The fluid is shunted from inside the eye to a bleb outside in a controlled fashion. This surgical procedure is done to lower the eye pressure when medical therapy or laser treatment has failed.
Glaucoma drainage devices like Ahmed glaucoma valve : for secondary or complicated glaucomas.
Trans Scleral Cyclo photo coagulation Performed in patients with no visual potential and uncontrolled are you pressure.