Glaucoma Pathophysiology

The main problem or pathology in glaucoma is caused by raised intraocular pressure. It is this raised pressure that compresses and damages the optic nerve. Once the optic nerve is damaged, it fails to carry visual information to the brain and this results in loss of vision.

The exact pathophysiology contributing to this is not fully understood. It is believed that the raised pressure on the retina causes the cells and nerve ganglions in the sensitive retina to die off (retinal ganglion apoptosis) and in addition the small blood vessels of the retina are also compressed depriving it of nutrients. This results in a clinically progressive loss of peripheral visual field and ultimately vision.

However, debunking this theory of high intraocular pressure alone that causes damage is the normal tension glaucoma. Here there is no rise of intraocular pressure. These patients are said to suffer from a problem in the blood vessels and perfusion and derangements of the immune system (autoimmune causes) that may lead to damage to the optic nerve.

Some studies show that optic nerve heads of these patients are particularly sensitive with damage occurring at much lower intraocualar pressures than in normal individuals. Thus they may also benefit from medications that can reduce intraocular pressure.

Causes of raised intraocular pressure

Normally the aqueous humor plays an important role in nutrient delivery and waste disposal for the cells. It is produced by the ciliary body epithelium and drains out through the trabecular meshwork at the anterior chamber angle. When this flow is disrupted the pressure within the eye builds up. This disruption can occur in two ways:-

  • Blockage at the drainage at the trabecular meshwork (in open angle glaucoma)
  • Narrowing of the angle of drainage (in angle closure glaucoma)

Glaucoma and age

Age is the most common reason for disruption to aqueous flow. With age the trabecular meshwork cells work less efficiently and this results in build up of aqueous humor within the anterior chamber of the eye.

In addition with age the lens also hardens and increases in size. This further narrows the anterior chamber of the eye and physically narrows the anterior chamber angle.

Further Reading

Last Updated: Jun 21, 2023

Dr. Ananya Mandal

Written by

Dr. Ananya Mandal

Dr. Ananya Mandal is a doctor by profession, lecturer by vocation and a medical writer by passion. She specialized in Clinical Pharmacology after her bachelor's (MBBS). For her, health communication is not just writing complicated reviews for professionals but making medical knowledge understandable and available to the general public as well.

Citations

Please use one of the following formats to cite this article in your essay, paper or report:

  • APA

    Mandal, Ananya. (2023, June 21). Glaucoma Pathophysiology. News-Medical. Retrieved on October 31, 2024 from https://www.news-medical.net/health/Glaucoma-Pathophysiology.aspx.

  • MLA

    Mandal, Ananya. "Glaucoma Pathophysiology". News-Medical. 31 October 2024. <https://www.news-medical.net/health/Glaucoma-Pathophysiology.aspx>.

  • Chicago

    Mandal, Ananya. "Glaucoma Pathophysiology". News-Medical. https://www.news-medical.net/health/Glaucoma-Pathophysiology.aspx. (accessed October 31, 2024).

  • Harvard

    Mandal, Ananya. 2023. Glaucoma Pathophysiology. News-Medical, viewed 31 October 2024, https://www.news-medical.net/health/Glaucoma-Pathophysiology.aspx.

Comments

The opinions expressed here are the views of the writer and do not necessarily reflect the views and opinions of News Medical.
Post a new comment
Post

While we only use edited and approved content for Azthena answers, it may on occasions provide incorrect responses. Please confirm any data provided with the related suppliers or authors. We do not provide medical advice, if you search for medical information you must always consult a medical professional before acting on any information provided.

Your questions, but not your email details will be shared with OpenAI and retained for 30 days in accordance with their privacy principles.

Please do not ask questions that use sensitive or confidential information.

Read the full Terms & Conditions.

You might also like...
Does your ADHD medication increase your risk of glaucoma?