It’s the second leading cause of blindness in the world but often goes undiagnosed. A leading expert gives the lowdown on glaucoma.
It’s known as “the silent thief of sight” because symptoms often don’t appear until it’s too late and irreversible damage to the eyes has been done.
Glaucoma affects the eye’s optic nerve – the nerve that sends visual information from the retina to the brain – and gets worse over time.
Here, Dr Saida Yasmeen, a specialist ophthalmologist at Aster Al Raffah Hospital in Ghubra, Muscat, gives an insight into the disease and the treatments currently available.
Glaucoma is the second leading cause of irreversible blindness worldwide. This is not because of a lack of effective methods for diagnosis and treatment. It is due to insufficient information available to the public and a low awareness of the implications of the disease. The disease is asymptomatic in its early stages while the patient’s vision suffers irreversible and cumulative damage. Visual disturbances are noted by the patient at the later stages on the way to blindness. Timely diagnosis and therapy could have prevented this deterioration.
Who is at risk for Glaucoma?
Anyone can develop glaucoma. Some risk factors include:
- Everyone over the age of 40
- People with a family history of glaucoma
- People with short sightedness (myopia) for open angle type and far sightedness( hyperopia) for close angle type
- Previous trauma to the eye
What are the symptoms of Glaucoma?
The open angle type of glaucoma is usually asymptomatic until a very late stage at which time the patient notices a loss of vision. By then it has usually progressed to a stage whereupon treatment of any form will not restore the vision. At an early stage, this type of glaucoma is usually detected by chance when the patient visits an eye doctor for some other eye complaint.
A patient with the closed angle type complains of eye pain, headache, seeing coloured haloes, decreased vision and redness.
How is Glaucoma diagnosed?
Your eye doctor will do the following tests to arrive at a diagnosis of glaucoma:
- Measure eye pressure with Applanation Tonometre (an instrument with a slip lamp equipped with forehead and chin supports and a tiny, flat-tipped cone that gently comes into contact with your cornea)
- Fundoscopy to evaluate the optic nerve
- Visual field test
- Gonioscopy to distinguish a closed angle from an open angle type of glaucoma
- Optical Coherence Tomography (OCT) to evaluate retinal nerve fibre loss
- Pachymetry to measure your central corneal thickness
How is Glaucoma treated?
Once a diagnosis of glaucoma has been established, your eye doctor will prescribe you eye drops (either single or a combination of two drops) to control your eye pressure. Eye pressure not controlled with eye drops can be treated with laser surgery. The treatment is aimed at reducing pressure on the eye to prevent your optic nerve from becoming damaged further. Treatment of any form will not restore the vision lost due to glaucoma.
Patients with closed angle type need to undergo a laser iridotomy to reduce the eye pressure and to prevent subsequent attacks of glaucoma.