Glaucoma can slowly steal a person’s sight without causing pain or obvious warning signs.
The disease damages the optic nerve, the important bundle of nerve fibers that carries visual information from the eye to the brain. Once glaucoma destroys part of a person’s vision, that loss is usually permanent.
A Swedish study suggests that hidden glaucoma may be surprisingly common among older adults. Researchers examined 560 people who were all 70 years old and found that almost 5% had the eye disease. About half of those with glaucoma did not know they had it before taking part in the research.
The work was part of the H70 study, a major Swedish research project that has followed the health of older people for decades. For this part of the project, participants received detailed eye examinations that could find signs of glaucoma even when people had not noticed changes in their sight. The research was published in the peer-reviewed journal Acta Ophthalmologica.
The finding matters because glaucoma often develops very slowly. In its early stages, it commonly affects side vision first, while the clearer central vision used for reading or looking straight ahead may remain normal. The brain can also help fill in missing visual information, making the damage even harder to notice.
Lead researcher Lena Havstam Johansson said finding previously unknown cases gives people a chance to start treatment before more sight is lost. Treatment cannot restore vision that glaucoma has already destroyed, but it can often slow or prevent further damage. For many patients, treatment begins with daily eye drops.
These medicines usually work by lowering pressure inside the eye. High eye pressure is an important risk factor because it can place stress on the optic nerve over time. However, the Swedish study also showed why checking eye pressure alone is not enough.
Many of the people whose glaucoma was newly discovered had eye pressure within the normal range. This type of glaucoma can still damage the optic nerve even though a pressure reading does not appear unusually high. A full eye examination can therefore include several checks, such as looking at the optic nerve and testing a person’s field of vision.
Age is one of the main risk factors for glaucoma, and family history also matters. People with a close relative who has the disease have a higher chance of developing it themselves. The Swedish findings supported the link between glaucoma and family history.
The researchers also looked at how glaucoma affected everyday life. Overall, people with the condition were just as physically active and emotionally well as people without it. They also did not appear to smoke or drink more than the other participants.
Still, some differences were important. People with glaucoma were more likely to report trouble seeing objects to the side, using stairs and noticing curbs when walking in the evening. These problems can make moving around less comfortable and may cause some people to become more cautious about going out.
The study adds to the evidence that regular eye checks become more important as people grow older. A person can have glaucoma while still believing that their eyesight is fine, so waiting for symptoms may allow the disease to progress unnoticed. People with a family history of glaucoma may have an especially strong reason to discuss regular testing with an eye-care professional.
The encouraging message is that an early diagnosis can make a major difference. Modern treatments can often keep eye pressure under control and protect remaining vision for many years. The Swedish research shows that finding the disease before a person notices it may be one of the best ways to preserve sight as people age.
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