Normal pressure glaucoma: normal intraocular pressure – optic nerve destroyed

Many people believe that glaucoma, also known as glaucoma, is associated with increased pressure in the eye. But that’s a mistake: the eye pressure is often in the normal range – but the optic nerve is still at risk. Anyone who, as a result of this misconception, decides not to take the prescribed anti-glaucomatous eye drops, i.e. the eye drops against glaucoma because they think their intraocular pressure is within the normal range, risks dying of the optic nerve cells and thus an irreversible loss of vision. We explain the connections.

What intraocular pressure is normal?

The average values ​​for intraocular pressure are between 10 and 21 mmHg (millimetres of mercury). The intraocular pressure values ​​fluctuate by around five mmHg over a day. The values ​​can be higher than usual, especially at night and early in the morning. The values ​​can also be higher in older people; 10 to 12 mmHg in children is considered normal.

Increased pressure in the eye, i.e. from 22 mmHg, is considered a risk factor for the development of glaucoma – but it does not necessarily have to happen. Conversely, the eye pressure does not have to be elevated to develop glaucoma (normal pressure glaucoma).

The intraocular pressure is measured using a so-called applanation tonometer. This device measures the pressure needed to deform a specific cornea area.

 

Also, examine the optic nerve.

Prof. Lutz E. Pillunat, Clinic Director of the University Eye Clinic Dresden and member of the professional association of ophthalmologists, knows the misjudgments in the diagnosis of glaucoma: “It is a fatal and unfortunately still widespread misconception that glaucoma is always associated with an increased intraocular pressure.”

In many cases of glaucoma, the pressure values ​​are within the normal range, and the optic nerve is nevertheless threatened. Therefore, a glaucoma check-up only makes sense if the optic nerve condition is assessed at the same time as the intraocular pressure is measured.

Normal-tension glaucoma: causes

“There are various possible reasons for glaucoma without a noticeably high intraocular pressure: A low tolerance limit – here, even a relatively low pressure destroys the sensitive nerve fibre cells,” says Prof. Pillunat. At the same time, the blood flow to the optic nerve can be disturbed – it is not supplied with sufficient oxygen and nutrients. Malregulations of the vascular system are characteristic of normal pressure glaucoma.

 

Eye drops to prevent glaucoma.

Another misconception is that glaucoma drugs only lower intraocular pressure. Many eye drops prescribed today also improve blood flow to the retina and the optic nerve.

“As a result of ignorance and errors, glaucoma is still one of the most common causes of blindness – despite reliable diagnostic methods and effective therapy concepts that can preserve vision,” explains Prof. Pillunat.

With early detection th, the best therapy

So that glaucoma can be detected and treated before damage to the optic nerve occurs, everyone age 40 should have an ophthalmological examination every two years as a precaution for early detection of glaucoma. This consists of examining the optic nerve and an intraocular pressure measurement.

If glaucoma is known in the family, it is advisable to carry out preventive check-ups from age 35 and annually. Closer screening for people with diabetes is also advisable.

If glaucoma has been diagnosed, it is crucial that the patient conscientiously applies the therapy prescribed for them by the ophthalmologist.

The statutory health insurance companies do not cover check-ups, but you should treat yourself to the low costs in your eyesight.