Ocular Hypertension Overview continued...
As of the year 2013, an estimated 2.2 million people in the United States had glaucoma and more than 120,000 are legally blind because of this disease. These statistics alone emphasize the need to identify and closely monitor people who are at risk of developing glaucoma, particularly those with ocular hypertension.
- Studies estimate that 3-6 million people in the United States alone, including 4-10% of the population older than 40 years, have intraocular pressures of 21 mm Hg or higher, without detectable signs of glaucomatous damage using current tests.
- Studies over the last 20 years have helped to characterize those with ocular hypertension.
- Recent data on people with ocular hypertension from the Ocular Hypertension Treatment Study have shown that they have an average estimated risk of 10% of developing glaucoma over 5 years. This risk may be decreased to 5% (a 50% decrease in risk) if eye pressure is lowered by medications or laser surgery. However, the risk may become even less than 1% per year because of significantly improved techniques for detecting glaucomatous damage. This could allow treatment to start much earlier, before vision loss occurs. Future studies will help to further assess this risk of glaucoma development.
- Patients with thin corneas may be at a higher risk for glaucoma development; therefore, your ophthalmologist may use a measuring device, called a pachymeter, to determine your corneal thickness.
- Ocular hypertension is 10-15 times more likely to occur than primary open-angle glaucoma, a common form of glaucoma. That means that out of every 100 people older than age 40, about 10 will have pressures higher than 21 mm Hg, but only one of those people will have glaucoma.
- Over a 5-year period, several studies have shown the incidence of glaucomatous damage in people with ocular hypertension to be about 2.6-3% for intraocular pressures of 21-25 mm Hg, 12-26% for intraocular pressures of 26-30 mm Hg, and approximately 42% for those higher than 30 mm Hg.
- In approximately 3% of people with ocular hypertension, the veins in the retina can become blocked (called a retinal vein occlusion), which could lead to vision loss. Because of this, keeping pressures below 25 mm Hg in people with ocular hypertension and who are older than age 65 is often suggested.