Glaucoma: clinical tips by Associate Professor Louis Roller, Faculty of Pharmacy and Pharmaceutical Sciences, Monash University
Eye disease and visual impairment increase three-fold with each decade of life after 40 years of age. They are often accompanied by isolation, depression and poorer social relationships, and are strongly associated with falls and hip fractures.
People at greater risk of visual loss are older people, those with diabetes, and those with a family history of vision impairment. Cataracts are the most common eye disease (42% of cases of visual impairment), followed by age related macular degeneration (AMD) (30%), diabetic retinopathy and glaucoma.
The leading causes of blindness in those over 65 years of age are AMD (55%), glaucoma (16%) and diabetic retinopathy (16%).
Glaucoma is a chronic optic neuropathy usually associated with raided intraocular pressure. The disease has a familial basis and can be made worse by coexistence of cardiovascular risk factors, including cigarette smoking. There is accumulation of extracellular materials within the trabecular meshwork leading to obstruction of aqueous outflow.
Glaucoma results in progressive damage to the optic nerve, which almost always begins with a subtle loss of peripheral vision. The main factor that leads to damage of the optic nerve is elevated intraocular pressure. If not diagnosed and treated, Glaucoma can progress to a loss of central vision and blindness.
There are two main types of glaucoma: open-angle glaucoma; this type develops slowly and without acute attacks. It is the most common type of glaucoma and closed-angle glaucoma; this type occurs acutely and is a medical emergency.
The symptoms of open-angle glaucoma are gradually progressive visual field loss and optic nerve changes.
The symptoms of closed-angle glaucoma include: sudden ocular pain, seeing halos around lights, red eye, very high intraocular pressure, nausea and vomiting, sudden decreased vision and, fixed, mid-dilated pupil(s)
Major risk factors for glaucoma include: age greater than 45, family history of glaucoma, black racial ancestry, diabetes, history of elevated intraocular pressure, high degree of nearsightedness (myopia), history of injury to the eye, use of corticosteroids, either in the eye or systematically and farsightedness (hyperopia).
Although nerve damage and visual loss from glaucoma cannot be reversed, glaucoma is an eye condition that can be controlled. Treatment can restore the ocular pressure and thus prevent or stop further nerve damage and visual loss. Treatment may include eye-drops (beta-blockers, prostaglandin analogues, alpha2 agonists and carbonic anhydrase inhibitors), laser treatments or surgery.
Advice on using eye drops
- wash hands thoroughly.
- sit or lie down.
- shake suspensions (cloudy liquids) gently before use.
- tilt head back and look upwards.
- gently pull down the lower eyelid to form a pouch.
- hold the bottle dropper near the lid, but do not let the tip of the bottle touch the eyes or skin.
- put one drop into the pouch.
- try not to blink, but close the eyes gently and do not rub them.
- apply gentle pressure with a finger against the inner corner of the eye (over the tear duct) for a few minutes. This increases the effectiveness of the medicine by reducing the amount that is drained from the eye.
- blot excess solution around the eye with a tissue.
- if putting more than one drop in the eye (of the same or different preparations), separate each drop by several minutes. This will prevent drops being washed out of the eye and might increase the amount of active ingredient that is absorbed.
As well as counselling and demonstrating the correct use of eye drops, pharmacists can counsel patients on reducing cardiovascular risk factors, such as eating a healthy diet, exercising sensibly, maintaining normal body weight, not smoking, limiting alcohol intake, maintaining good blood pressure and blood sugars and ensuring that lipids are within the normal range – that is, maintaining a healthy lifestyle.