What is glaucoma and intraocular pressure? Understanding the disease, risks, and management
Glaucoma is a group of eye disorders causing optic nerve damage, often linked to raised intraocular pressure but not always. Risk factors include age, myopia, diabetes, hypertension, and smoking. It may be asymptomatic initially, later affecting vision. Diagnosis uses tonometry, gonioscopy, and slit-lamp examination. Treatment includes medicines or filtration surgery.
Definition of intraocular pressure Intraocular pressure refers to the pressure that is exerted by the fluids in the eyes on the coats of the eyeball. The normal intraocular pressure is around 10 to 21 mm of mercury, and it is maintained by a balance in the formation and outflow of the aqueous humour. (Image: canva)
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Role of aqueous humour The aqueous humour is the clear and watery fluid present in the front part of the eye, in the anterior and posterior chambers. It provides the eyeball its shape and supplies important nutrients to various structures of the eye like the cornea and the lens. It also aids in removing waste products from the eye.(Image: canva)
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Aqueous humour flow problems The aqueous humour flows through the anterior to the posterior chamber. Any block in its flow can cause problems. Glaucoma refers to a group of disorders that cause progressive damage to the nerve in the eye (the optic nerve), which then leads to a specific pattern of vision problems, that are irreversible.(Image: canva)
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Glaucoma and optic nerve damage Glaucoma may or may not be associated with an increase in the intraocular pressure, as an increased IOP may be one of the most common risk factors for glaucoma, but it certainly is not the only factor that influences the development of this condition. Sometimes, the intraocular pressure may be raised without any evidence of glaucoma as well.(Image: canva)
Types of glaucoma Glaucoma may be present since birth, called primary congenital glaucoma, or it may develop with other associated anomalies. Glaucoma has other types too, like open angle, angle closure, and mixed mechanism glaucoma. Secondary glaucomas are also seen in some people.(Image: canva)
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Raised pressure and age Raised intraocular pressure can occur due to multiple reasons, which can thus lead to glaucoma. The mean IOP has been known to increase after the age of forty years, and is more common in females in the older age group. However, there is no gender preponderance between twenty to forty years.(Image: canva)
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Open angle glaucoma risk factors In the case of open angle glaucoma, there is no obvious systemic cause that could lead to a raised intraocular pressure. Its risk also increases with age, and people with near-sightedness (myopia), where a person is not able to see far off things, are more susceptible.(Image: canva)
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Diabetes, smoking and blood pressure People with diabetes are also more likely to develop open angle glaucoma. Cigarette smoking may also increase the risk, and it has been found that people with raised blood pressure levels develop glaucoma more than people with normal blood pressure levels.(Image: canva)
Clinical features The disease may initially be insidious in onset and asymptomatic, but later it can cause a significant problem in the vision of the affected individual. Mild headache and eye ache are seen, along with difficulty in reading. A delayed adaptation of the eyes to the dark is also common.(Image: canva)
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Management and treatment options The ophthalmologist may advise investigations like tonometry (measures the intraocular pressure) and gonioscopy (assess the drainage angle of the eye). Slit-lamp examination and perimeters may also be recommended. Therapeutic choices like medical therapy or filtration surgery can be considered to treat this condition.(Image: canva) Disclaimer: This article, including health and fitness advice, only provides generic information. Don’t treat it as a substitute for qualified medical opinion. Always consult a specialist for specific health diagnosis
Rajeshwaari Kalla is a freelance health and wellness writer
