Eye Problems - Cataract and Glaucoma

Cataract and Glaucoma are the common types of eye problems and are a natural part of aging. Many people above the age of 60 suffer from one or both.

Cataract

Cataract is a disease of the eye where the vision becomes hazy due to the cloudiness of the eye lens. The lens of the eye is generally clear and helps in focusing the light which enters the eye on the retina. The retina is the tissue which is very light sensitive and is found behind of the eyes. A clear image can only be formed when the lens and the area ahead of the retina are transparent and clear. The light reaching the retina stimulates a chemical reaction which again creates an electrical response which travels to the brain via the optic nerve. The brain finally interprets the image making it possible for us to see.

In cataract, the lens becomes cloudy and thus the image formed is blurred and the vision is not clear. The seriousness of the disease depends on the extent of cloudiness. Cataracts develop with age and are very common in aged individuals. It can develop either in one eye or in both.

Once formed in one eye it can develop in the other eye also. It is not a contagious disease and is not painful. In most cases, a person’s vision can easily be restored with the help of cataract surgery.

Cataracts vary in types based on their location, extent of clouding and the cause behind it.

• Nuclear cataract is when clouding takes place only in the nucleus.
• A cortical cataract is the clouding of the lens cortex only.
• Sub capsular cataract is when the clarity of the lens capsule is lost.
• Age related cataract is normally referred to as senile cataract.

In simple words, when the normal transparency of the eye lens is lost it is termed as cataract. It can be mild, severe or moderate and also advanced or early. A completely opaque lens is mature cataract and an immature cataract is not opaque.

Causes of cataract can be age, injury to the eye, eye surgery, diabetes, iritis, myotonic dystrophy, Wilson’s disease, Down’s syndrome, galactosemia etc. some medicines when taken for long can also cause cataracts.

Initially symptoms may not be visible but in the advanced stage decreased vision, lost contrast sensitivity, loss of color vision, disturbing glare, haloes, diminished night vision, double vision etc. it can be easily diagnosed during a routine checkup of the eye. Corrective glasses and surgery are the main form of treatments.

Glaucoma

Glaucoma generally is associated with the optic nerve of the eye. One of the main functions of the optic nerve is to receive nerve impulses generated when light enters the eye, transmits them to brain, and finally form the image.

Glaucoma begins with the loss of peripheral vision and then progresses to the optic nerve. If this condition is left untreated, it can result in complete blindness. Glaucoma is often related to elevated intraocular pressure which in turn damages the optic nerve. Today it is the most common cause of blindness all over the globe.

The optic nerve is the main visual nerve of the eye. The firmness of the eye is maintained by an intraocular pressure ranging from 8 to 22mm mercury. If the pressure rises, too much hardening of the eye takes place and damages the vulnerable fibers of the optic nerve.

Early diagnosis of glaucoma can help in treating the disease successfully.

The main risk factors are age, genetic, diabetes, elevated intraocular pressure, nearsightedness, eye injury; long-sightedness etc.

Open-angle glaucoma, low-tension glaucoma, congenital glaucoma, pigmentry glaucoma, exfoliative glaucoma, angle-closure glaucoma are the various types of glaucoma, initially the symptoms are not visible. In advanced cases, peripheral loss of vision is common, hazy vision, haloes, eye pain, vomiting, headache, nausea, blurred vision etc.

Glaucoma can be successfully diagnosed during normal eye check up and by tonometry, pachymetry, gonioscopy, opthalmoscopy; visual field testing etc. but the damage caused to the eye by glaucoma is generally not reversible but can only be controlled. This can be done by controlling the intraocular pressure and preventing any further damage and loss of vision. Treatment is generally done with the help of pills, eye drops, surgery or laser.

Laser procedures involve laser iridotomy, laser trabeculoplasty and laser cyclo-ablation. Surgical procedures comprise of trabeculectomy, aqueous shunt devices, viscocanalostomy etc. Open angle glaucoma can usually not be prevented.

The damage to the optic nerve and loss of vision can however be prevented only if the diagnosis is done at an early stage. Secondary types can be prevented by reducing stress and trauma to the eyes and treating any inflammation causing secondary glaucoma.

Most of the times, surgery is the best remedy for the treatment of both cataract and glaucoma. With age, these two eye problems are likely to develop. Thus, a regular check up of the eyes is recommended.