A glaucoma suspect is a person who may develop glaucoma. There are two types: (1) those that have suspect optic discs (2) those that have suspect visual fields. Often, infact, people have suspicious findings of both.
WHO IS AT RISK?
Certain risk factors are associated with the development of glaucomatous damage. The greatest risk factor being a family history of glaucoma, and studies have revealed that the risk of having glaucoma is increased 3.7-fold for those who have siblings with primary open-angle glaucoma. This is closely followed by glaucoma in a parent. Further risk factors include:
• increasing age
• race, particularly African American, or West African, or Carribean
• diabetes
• congenital eye abnormalities, especially in the appearance of the optic nerve
• trauma to the eye indicating optic nerve damage because of an isolated incident but which may not be progressive problems associated with the restriction of blood supply to the optic nerve as in vasospastic disorders (spasms or constrictions of the blood vessels) and / or heart disease
• narrow chamber angles
• nearsightedness (myopia)
• raised intraocular pressure (ocular hypertension)
• pseudoexfoliation - where flakes of material produced inside the eye obstruct the trabecular meshwork
• pigment dispersion caused by the iris releasing pigment inside the eye which obstructs the trabecular meshwork, resulting in a raise in intraocular pressures with a risk of glaucoma increasing by 25-50%
• history of uveitis (inflammation of the uvea, which is made up of the iris, the ciliary body, and the choroid)
• central retinal vein occlusion where the vein in the central part of the retina becomes blocked
• previous or current use of topical steroids - these can cause elevated intraocular pressure in certain people resulting in damage to the optic nerve
A person with glaucoma in one eye is at an increased risk of future damage, and 29% of untreated undamaged second eyes will experience vision loss in average of around 5 years
SYMPTOMS
Glaucoma suspects do not usually experience any symptoms. However, people with possible angle-closure glaucoma may experience intermittent headaches, see haloes, or have blurred vision. Unfortunately, once people with glaucoma have noted some vision loss, significant amounts of optic nerve damage and vision loss will have already occurred, and damage to the optic nerve and vision loss are permanent.
SIGNS
Lack of symptoms associated with glaucoma mean regular eye examinations of between three and twelve months with an ophthalmologist or optometrist are essential depending on the degree of associated risk factors. Tests may reveal
signs of elevated intraocular pressure (IOP) and notable differences in pressure between each eye - although raised pressures alone are not sufficient for a diagnosis of glaucoma as some eyes undergo damage at pressures of less than 18 mmHg, while others tolerate pressures of more than 30 mmHg, and as many as 50% of people with optic nerve damage or visual field changes due to glaucoma have pressures of less than 21 mmHg on initial testing.
Signs of damage to the optic nerve:
• peripheral (side) vision defects
• optic disc changes or defects
• narrow or closed chamber angles
TREATMENT
The decision to treat a glaucoma suspect will be made by the ophthalmologist. Initially, observation with frequent eye examinations may be all that is required. Medication in the form of eye drops may be prescribed to reduce the risk of progression, as studies have shown that medications such as prostaglandin analogues and beta blockers have been beneficial in lowering intraocular pressure. This reduces the risk of subsequent damage to the optic nerves. In cases where progression to glaucoma is seen, along with optic nerve damage and/or visual field defects, medical treatment will often start immediately, which would include eye drops and surgery later if drops are ineffective.
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