You know that emotion of exasperated stupidity you feel when you realize something has been going wrong right under your nose without you noticing and it eventually blows up in your face, yet you could have easily done something about it? That is the story of glaucoma, the only difference is that it happens above your nose, in your eyes.
Glaucoma is a group of eye conditions which result in damage to the major nerve of the eye (the optic nerve) and results in gradual loss of vision.
The damage to the optic nerve is usually related to an increase in the pressure inside the eyeball (the intraocular pressure).
The loss of vision occurs stealthily, starting from the periphery and closes up the field of vision into a narrow central space, a situation referred to as tunnel vision, because of its likeness to looking out through a tunnel or binoculars. Eventually, the tunnel closes up and there is total loss of vision.
According to the World Health Organization (WHO) “glaucoma is now the second leading cause of blindness globally, after cataracts. Glaucoma, however, presents perhaps an even greater public health challenge than cataracts: because the blindness it causes is irreversible”.
Also, unlike cataracts, the commonest type of glaucoma (open angle glaucoma) typically does not present with any early symptoms and before one is aware it is in its late stages. There is no pain, no observable changes in the structures of the eyes, no drastic visual disturbances; yet, there is progressive loss of vision. This is why glaucoma is infamously referred to as “the silent thief of sight”.
So if there are usually no symptoms, how does one know they have glaucoma?
It may be difficult to determine whether or not you have glaucoma, but a knowledge of the factors that make it more likely is a good place to start.
The presence or absence of these predisposing factors is a good measure of the likelihood of developing glaucoma and they are as follows:
• Age is by far the most important risk factor for glaucoma. As you age the risk for glaucoma increases commensurately. Most cases of glaucoma occur after the age of 40 years, and the risk is particularly increased in those above 60 years.
• Your ethnic background or race also determines your risk for glaucoma. Individuals of African descent are at particularly high risk for glaucoma. The onset of glaucoma in the African race also occurs earlier than with other races. Some studies have put the prevalence of Glaucoma in individuals above 40 years in certain geographic regions of Ghana to be about to 1 in 12, which is quite high.
• A family history of glaucoma, e.g. in father or mother or first generation uncle or aunt, is a recognized risk factor for glaucoma. This hereditability of glaucoma suggests that there may be one or more genes whose defect may increase the likelihood of developing glaucoma. Most of these genes are yet to be identified though. However, in a form of glaucoma that occurs in very young individuals a clear genetic link has been identified.
• Prolonged use of steroid medications can increase one’s risk for glaucoma. Prolonged use of steroid-containing eye drops is particularly notorious for increasing the pressure in the eye, which increases the risk for glaucoma. The risk for glaucoma is also increased when these steroids are taken via other routes, e.g. long-term oral use of prednisolone to manage asthma can increase the risk for glaucoma- thankfully, this is an outdated practice.
• The presence of medical conditions like diabetes, high blood pressure, heart diseases and hypothyroidism (a thyroid gland functioning below normal) may also increase a person’s risk for developing glaucoma.
• Previous or current eye conditions. Injuries to the eye, whether blunt (bruising the eye) or penetrating (piercing into the eye) can cause an increase in the pressure in the eye. This may lead to an acute onset of glaucoma or the effect may be delayed and glaucoma develops many years after the injury. Also, problems with the structures of the eyes (like the lens and retina) can increase the risk for glaucoma, as can tumors and inflammation of the eyes.
The absence of these risk factors does not necessarily exclude glaucoma. It can develop even when there are no identified risk factors. Fortunately, these cases are few and far between. Glaucoma my thus not be entirely preventable, but its damaging effects on vision can be slowed and the eventual result of blindness can be prevented. And this is how:
1. Identify your risk factors for glaucoma. Those with a family history of early onset glaucoma should take particular note of the possibility of developing glaucoma earlier than normal.
2. After the age of 40, those with risk factors should endeavor to have at least 1 complete eye examination each year. Those without any risk factors can do this 2 to 3-yearly until they turn 60, when yearly reviews is recommended.
After a diagnosis of glaucoma is made appropriate treatment is commenced, which usually involves instillation of drops into the eyes for the rest of the individual’s life.
The temptation for most is to stop using these eye drops after a while because they do not feel, and have probably never felt, ill; this is dangerous and can be the difference between irreversible blindness and a healthy vision.
As people tend to live longer nowadays the incidence of glaucoma is also rising. The blindness that comes with glaucoma is irreversible and that is why it needs to be identified early and managed well. There is absolutely no reason to be blind from glaucoma when it can be beaten so easily.
Glaucoma is stealthy, but glaucoma should not be the end of your sight.
The conversation continues on the Citi Health Chat this Wednesday at 12.30pm
By: K.T. Nimako (MB ChB)
Dr. Kojo Nimako is a private medical practitioner with an interest in public health and Citi FM’s Chief Medical Correspondent.
He is also the Executive Director of Helping Hand Medical Outreach, an NGO focused on health education.
E-mail: [email protected]