The Founder and Chief Executive Officer of Ladkem Eye Hospital, Dr Festus Oshoba, has warned that glaucoma accounts for about 25 per cent of blindness and often causes irreversible vision loss before patients become aware of the disease.
Oshoba, who described glaucoma as the “thief of vision,” said the condition usually progresses without pain, redness or other obvious symptoms, leaving many patients unaware until significant damage has been done to the optic nerve.
According to him, by the time many people with glaucoma begin to notice visual problems, they may have already lost about half of their optic nerve function.
“Glaucoma is responsible for about 25 per cent of blindness all over the world and also in Nigeria,” Oshoba said.
He explained that glaucoma is now broadly defined as a group of diseases that affect the optic nerve, resulting in progressive loss of vision and, in severe cases, blindness.
The eye specialist said the disease can affect people of all ages, including children born with glaucoma, while others may develop the condition later in life.
He identified heredity, eye injury, inflammation and other medical conditions as some of the factors associated with glaucoma.
Oshoba said the disease damages the optic nerve, which transmits visual signals from the eye to the brain, adding that the damage can occur gradually without the patient noticing any immediate change in vision.
He explained that glaucoma often affects peripheral vision first, with the field of vision progressively narrowing until the patient may eventually lose sight completely if the disease is not detected and managed early.
“Most people who have glaucoma, by the time they discover it, they are already bumping into objects. About 50 per cent of their nerves may have been damaged,” he said.
The ophthalmologist also raised concerns about the prevalence of glaucoma in the South-East, describing the region as a major hotspot for the disease based on findings from studies conducted in Nigeria.
He said genetic factors play a significant role in the development of some forms of glaucoma, citing cases of multiple members of his own extended family who lost their sight to the disease.
Oshoba, however, stressed that having a normal eye examination at a particular time does not guarantee that an individual will never develop glaucoma.
He said the condition can develop later in life, making regular eye examinations critical to early detection and prevention of blindness.
“Somebody cannot say, ‘I don’t have glaucoma, therefore I will never have glaucoma.’ They can acquire it at 75, 80, 90 or even 100. Nobody knows,” he said.
He urged people, particularly those with a family history of glaucoma or other risk factors, to undergo comprehensive eye examinations at least once a year.
According to him, glaucoma screening should include tests to measure intraocular pressure, assess the optic nerve and nerve fibre thickness, examine the visual field and check other parameters of the eye.
Oshoba said people with a large optic cup, which may sometimes be mistaken for glaucoma, should undergo detailed examinations before a diagnosis is made.
He explained that some people naturally have a large optic disc cup but may not have glaucoma if the optic nerve, nerve fibre layer and visual field remain normal, a condition referred to as physiological cupping.
He added that some individuals may also have narrow drainage angles in the eye, which could increase their risk of certain forms of glaucoma and require close monitoring or preventive intervention.
“The key to the treatment of glaucoma is early detection and prevention,” Oshoba said.
He said treatment options could include regular monitoring and the use of eye drops to lower eye pressure when necessary, while some patients may require other interventions depending on the type and severity of the condition.
Oshoba advised Nigerians not to wait until they experience pain or significant vision loss before seeking an eye examination, noting that the silent nature of glaucoma makes routine screening the most effective strategy for preventing avoidable blindness.
He said: “The message to the world is that there is a disease that makes people blind, and the person does not even know. It does not cause pain, it does not cause redness and it does not cause anything.”
The eye specialist urged families with a history of glaucoma to take regular screening seriously, saying early diagnosis remains the best chance of preserving vision.