Glaucoma & Eye Pressure

by Pamela Dove
(N.C.)

My optometrist told me during an eye exam that my glaucoma test results were in the 20's. He said 2 years ago it was in the teens and that was a normal rating. He asked me to return in 6 months to be checked again. Should I seek a second opinion?

When monitoring patients for their risk of developing Glaucoma, one of the factors we can easily measure is Intraocular Pressure (IOP). It is measured in millimetres of mercury (mmHg). 'Normal Pressure' is considered to be between 8 and 23mmHg.

Every person's eye pressure varies throughout the day, up to 4 mmHg. So your eye pressure could be in the teens on one visit and in the low 20s on another visit, depending on time of day and still be completely normal.

Your Optometrist will be monitoring your eyes for asymmetric changes - one eye's pressure being higher than another by a significant degree (more than 2mmHg difference). Or looking for an overall upward trend - both eyes having consistently higher pressure over time, especially if it stays above 23mmHg.

It is normal for an Optometrist to ask you to come back at a shorter interval if your pressure is higher than previously, to make sure the next time it is back at your "normal" level.

Glaucoma is easily controlled with medication so it is worth detecting early. Unfortunately the very early signs can be quite subtle and take a number of examinations to see if there is a consistent trend. Eye pressure is only one indicator of risk. People with consistently elevated pressure are at a much higher risk of developing Glaucoma. Other people with IOP in the 'normal' range can still get Glaucoma, too.

Have a chat to your Optometrist about your concern for your peace of mind, however it sounds like your Optometrist is just making sure that your eye pressure isn't trending upward over time.

Read more about Signs of Glaucoma and Symptoms of Glaucoma.