5. How many people have glaucoma?
Prevalence studies the world over have revealed that 66.8 million people have glaucoma and about seven million people are blind due to glaucoma. Nearly three fourths of this population reside in China, India and other developing nations of South east Asia. Recent studies in South India reveal that nearly 2.5% individuals aged over forty years have one form of glaucoma or the other. This would approximately translate to about 7.5 million persons in India with glaucoma. Glaucoma is the most common cause of irreversible blindness in India and ranks next to cataract and uncorrected refractive errors as a significant cause of visual impairment.
6. How many people have glaucoma and don't know it?
Studies in the western population reveal that at least half of those with glaucoma were not aware of the potentially blinding disease. The number of people unaware of glaucoma tends to be much higher in the developing world. Population surveys in Madurai and Hyderabad had highlighted that more than 90% individuals diagnosed with glaucoma were not aware of the problem.
7. How many people are blind due to glaucoma?
It is a leading cause of blindness, accounting for between nine and 12 percent of all cases of blindness. The rate of blindness from glaucoma is between 93 and 126 per 100,000 population over 40. Nearly seven million people are blind due to glaucoma the world over. From the statistics available from various population studies in India, about a million are blind from glaucoma.
8. Who is at highest risk of developing glaucoma?
The primary Risk factors for glaucoma include:
Age: Increasing age is one of the principal risk factors in glaucoma. Although children and new born are likely to get glaucoma, it is common in individuals over the age of forty. With every decade of life, the risk of glaucoma exponentially increases.
Family History: Most primary glaucomas appear to be hereditary and genetically determined. Individuals with a family history of glaucoma are at significantly more risk of developing the disease than the general population.
Race: Ethnicity and racial backround appears to influence glaucoma. Persons of African ancestry have about four to five times the risk of developing open angle glaucoma than the white population. Asians, especially the Chinese, have enhanced risk of angle closure glaucoma, while the Japanese are at increased risk of normal pressure glaucoma.
Refractory Errors: Near sighted individuals (Myopia) are at increased risk of open angle glaucoma, while the far sighted (hyperopic) individuals are likely to have increased chance of angle closure glaucoma.
Intraocular Pressure: The level of the intraocualr pressure is the single most important risk factor in pathogenesis of glaucomatous visual loss. Although individuals with normal intraocular pressures (12-20 mmHg) are known to develop optic disc damage (Normal Pressure glaucoma), eyes with pressures exceeding 21 mmHg are at increased risk of glaucoma. In general, higher the eye pressures, greater is the likelihood of optic nerve damage from glaucoma.
Diabetes: The role of diabetes as a risk factor in glaucoma is not certain. But diabetes can lead to secondary glaucoma from retinal damage; hence a strict glycaemic control and periodical eye evaluation is mandatory.
9. How is glaucoma detected?
Most glaucomas are asymptomatic and are diagnosed when an individual consults an eye doctor for an unrelated problem. Early detection is crucial since treatment is ineffective when visual loss from glaucoma is advanced. All ophthalmologists are trained to diagnose glaucoma with simple clinical examination, which includes measurement of the intraocular pressure, evaluation of the optic nerve and examination of the visual fields. These procedures are simple and can be carried out in the outpatient Rooms with topical anaesthesia.
10. Can glaucoma be cured?
Glaucoma is a condition in which the visual neurons in the retina and the optic nerve are damaged permanently beyond repair. Visual loss and blindness form glaucoma cannot be cured or reversed. Early recognition of glaucoma and appropriate and regular treatment and periodical follow up by an ophthalmologist can preserve vision and delay vision impairment.
11. Can glaucoma be prevented?
Glaucomas that are hereditary cannot be prevented but early detection and appropriate treatment, strict compliance with the suggested treatment and regular follow up examination by an eye care professional can considerably reduce the possibility of blindness due to glaucoma. Secondary glaucomas due to trauma, inflammation or mature cataracts could be managed by the treatment of the primary condition.
12. What is the best defense against glaucoma?
The most effective way to prevent visual loss from glaucoma is a periodical evaluation by an eye specialist. The eye examination need to performed at least once in two years in individuals who are over forty years. In persons with risk factors, such as those with a relative with glaucoma, the eye examination should be on a more frequent basis, and also should commence earlier in life, preferably when they are about 20-30 years of age. Since glaucoma in the young is not uncommon, all children old enough to cooperate for an eye examination should also be periodically evaluated by an eye specialist.