Normal Pressure Glaucoma

Normal Pressure Glaucoma

Normal pressure glaucoma is a form of glaucoma that affects the optic nerve and can lead to vision loss. It is characterized by damage to the optic nerve and loss of visual field despite the fact that the intraocular pressure (IOP) is within normal limits unlike other types of glaucoma where the pressure is elevated.

What causes normal pressure glaucoma?

The cause of normal pressure glaucoma is unknown. We believe that in some people the optic nerve has an intrinsic predisposition to the disease, or that the disease occurs as a result of reduced blood flow to the optic nerve.

What are the risk factors?

– Heredity

– Progress of age

– Bad regulation of blood flow in the optic nerve (due to arterial hypertension or hypotension mainly during sleep)

– Diabetes

– Migraine

– Other vasoconstrictive diseases such as Raynaud’s phenomenon.

– Sleep apnea

– Blood loss – hemorrhagic shock

What are the symptoms?

Normal-tension glaucoma usually develops slowly and may not cause noticeable symptoms in the early stages. As the condition progresses, the following symptoms may appear:

  • Gradual loss of peripheral vision: At first, you may not notice any changes in your vision, but over time, you may begin to notice blind spots appear in your field of vision.
  • Difficulty with night vision: Vision problems in low light conditions or at night may become more apparent.
  • Increased sensitivity to bright light: You may experience increased sensitivity to bright lights or glare.
Κεντρικό και κατώτερο ρινικό σκότωμα ( απώλεια οπτικού πεδίου) σε ασθενή που πάσχει από γλαύκωμα φυσιολογικής πίεσης.
Αυξημένη κοίλανση οπτικής θηλής και αιμορραγία σε ασθενή που πάσχει από γλαύκωμα φυσιολογικής πίεσης.

What tests are needed for diagnosis?

 

A good history is taken with an emphasis on the presence of cardiovascular disease, migraine or Raynaud’s phenomenon. In addition, we look for neurological disease, eye or head trauma, stroke, acute blood loss, and a history of eye inflammation or other disease requiring cortisone treatment.

Then a complete ophthalmological examination is needed with measurement of visual acuity, color perception, intraocular pressure, pachymetry (measurement of corneal thickness). In addition, we perform a thorough examination of the anterior chamber of the eye, gonioscopy and examination of the optic nerve and the retina under mydriasis. Furthermore, we recommend performing a visual field test, optical coherence tomography of the optic nerve and color photography of the optic nerve.

In some cases where we suspect another pathology (damage to the optic nerve that is not due to glaucoma) we may refer the patient for CT and/or magnetic resonance imaging of the brain. In addition, we always request an evaluation by a cardiologist to treat factors that may be affecting blood flow to the optic nerve and in some cases sleep study (polysomnography) to test for sleep apnea.

What is the treatment?

Some studies have shown that normal pressure glaucoma does not worsen despite the fact that patients are not receiving treatment. In cases of worsening damage, the only proven treatment is to lower the intraocular pressure even though the pressure is already within normal range.

The reduction of intraocular pressure is achieved with eye drops, with laser trabeculoplasty-SLT ( link ) or with surgery such as trabeculectomy ( link ) or insertion of an aqueous humor drainage device ( link ) in more advanced cases. We believe that a 30% reduction in pressure is sufficient to stop the progression of the glaucomatous damage.

In addition, the correct treatment of diseases of the cardiovascular system (arterial hypertension, hypotension, arrhythmias) as well as diabetes mellitus is important in order to stabilize the blood flow to the optic nerve. Finally, patients suffering from sleep apnea benefit from treatment with cPAP device.

Remember, early diagnosis and early treatment are essential to manage normal pressure glaucoma. If you have any concerns or notice changes in your vision, you can consult us immediately for a thorough evaluation and appropriate treatment.