World Glaucoma week is designated March 10th-16th in 2019. As the leading cause of irreversible blindness in the world, glaucoma remains a devastating affliction of our times, and is growing in the number of people who are affected. The World Health Organization (WHO) estimates in 2014 that 4.5 million persons globally are blind due to glaucoma and that this number will rise to 11.2 million by 2020. Here in Trinidad and Tobago, the three most common conditions being seen at the public health eye clinics, which if untreated can lead to vision impairment and blindness, are glaucoma, diabetes and cataracts, with glaucoma accounting for about 65% of these patients. Prevention and early treatment of glaucoma are key aspects in combating this disease. There is no cure for glaucoma, and vision loss is irreversible. However, medication or surgery (traditional or laser) can halt or slow further vision loss. Early detection is essential to limiting visual impairment and preventing the progression towards severe visual handicap or blindness.
Glaucoma is a group of eye diseases that cause progressive damage of the optic nerve at the point where it leaves the eye to carry visual information to the brain. If left untreated, most types of glaucoma progress (without warning nor obvious symptoms to the patient) towards gradually worsening visual damage and may lead to blindness. Once incurred, visual damage is mostly irreversible, and this has led to glaucoma being described as the "silent blinding disease" or the "sneak thief of sight". It is noteworthy that due to the silent progression of the disease - at least in its early stages - up to 50% of affected persons in the developed countries are not even aware of having glaucoma. This number may rise to 90% in underdeveloped parts of the world.
Some forms of glaucoma may occur at birth ("congenital") or during infancy and childhood. In most cases however, glaucoma appears after the 4th decade of life, and its frequency increases with age. There is no clearly established difference in glaucoma incidence between men and women. The vast majority is "primary", i.e. they occur without a known cause. It was once believed that the cause of most or all glaucoma was high pressure within the eye (known as intraocular pressure - sometimes abbreviated as IOP). It is now established however, that even people without an abnormally high IOP may suffer from glaucoma. Intraocular pressure is considered therefore today as a "Risk Factor" for glaucoma, together with other factors such as racial ancestry, family history, high myopia and age. Some people have a higher than normal risk of getting glaucoma. This includes people who:
are over age 40
have family members with glaucoma
are of African, Hispanic, or Asian heritage
have high eye pressure
are farsighted or nearsighted
have had an eye injury
use long-term steroid medications
have corneas that are thin in the center
have thinning of the optic nerve
have diabetes, migraines, high blood pressure, poor blood circulation or other health problems affecting the whole body
The only sure way to diagnose glaucoma is with a complete eye exam. A glaucoma screening that only checks eye pressure is not enough to find glaucoma. Thus, all citizens should take responsibility for his or her own health and make preventive health care a part of your family’s life. Visit your Ophthalmologist or join the free Ophthalmology (eye) Clinics offered at the following public health institutions where a wide range of vision and eye care services, inclusive of surgery, are offered if referred from your local health center. Once appropriately referred, these facilities can be accessed at the following instutions:
The Port of Spain General Hospital
The Eric Williams Medical Sciences Complex;
The Sangre Grande Hospital; and
The San Fernando General Hospital.
It is a common observation though, that many of these public clinics are flooded with patients and the waiting list is quite long. When Dr. Declan Mahabir, consultant Ophthalmologist at the Eric Williams Medical Sciences Complex (EWMSC), was asked if this is an indication of a high incidence and prevalence of the disease, he indicated that this is true to some extent as conditions of the eye like glaucoma and cataract are indeed quite common. He stated in fact that glaucoma is the leading cause of irreversible blindness in T&T, especially among elderly patients. He added that there are also other factors at play where glaucoma is concerned in T&T because, unlike where he was trained in Ireland, he has noticed that there are patients presenting at younger age groups. He attributed this to the higher numbers of people of African descent in our population as well as environmental factors that seem to contribute to a higher incidence and prevalence of glaucoma in the South American region. He also said that other genetic factors are at play in our population as well as other unidentified factors that can only be unearth with further research.
However, he also said that the system of referral needs to revised as and policies need to be changed to ensure an efficient referral system would cut down on the overwhelming numbers that are referred to the eye clinics. Within the community setting he said, an adequate history and examination could identify patients at high risk for glaucoma. He mentioned that there are even certain medications like psychiatric drugs such as Selective Serotonin Reuptake Inhibitors (SSRIs) that confer protection from glaucoma. He added that other antihypertensive medications like Beta-Blockers and Calcium Channel Blockers may mask symptoms and signs of the disease that community physicians need to look out for in their patients. With regard to enhancing screening within the primary care clinics Dr. Mahabir pointed out that, in addition to continuous medical educational training among these physicians, special screening tools like the tonopen and non-contact tonometry can be made available in the primary care setting once primary care physicians are trained to use them. These would go a long way in achieving appropriate and efficient referrals. This would result in a reduction in the number of patients referred to the eye clinics, leading to a more efficient flow in the clinic by reduction in waiting times for appointment and procedures.
-Dr Visham Bhimull