Many times it can be confused with a cataract which also manifests as a painless, gradual loss of vision. The difference is that in the case of cataract, the loss of vision is fully recoverable using a simple surgery called Phaco.
Our eyes contain a clear fluid called aqueous humor, which is continuously produced in the eye to bath and nourish the structures inside it. The fluid normally drains out of the eye through drainage canals in a fine meshwork located around the edge of the iris (the colored part of the eye that surrounds the pupil). In people with glaucoma, the fluid fails to drain due to some defect and thus increases the pressure inside the eyes called raised Intraocular Pressure (IOP) (or Tension).
Anyone can develop glaucoma. Some people are at higher risk than others. They include:
Once the lens is removed, it may be replaced by one of the three options:
It happens when the eye’s drainage canals become clogged over time. The inner eye pressure (also called intraocular pressure or IOP) rises because the correct amount of fluid can’t drain out of the eye. With open-angle glaucoma, the entrances to the drainage canals are clear and open. The clogging problem occurs further inside the drainage canals, similar to a clogged pipe below the drain in a sink. Most people have no symptoms & no early warning signs. If open-angle glaucoma is not diagnosed & treated, it can cause a gradual loss of vision. This type of glaucoma develops slowly and sometimes without noticeable sight loss for many years. It usually responds well to medication, especially if caught early and treated. This form of glaucoma is more common in Caucasians than others.
This type of glaucoma is also known as acute glaucoma or narrow-angle glaucoma. It is more common in Asians and is very different from open-angle glaucoma in which the eye pressure usually rises very quickly. It happens when the entrance to the drainage canals is very narrow or covered over, like a sink with something covering the drain. Symptoms of angle closure glaucoma may include headaches, eye pain, nausea, rainbows around lights at night, and very blurred vision.
In this type of glaucoma, the optic nerve is damaged even though intraocular pressure (IOP) is not very high. Lowering eye pressure by at least 30 percent through medicines slows the disease in some people. A comprehensive medical history is essential in identifying other potential risk factors, such as low blood pressure, that contribute to low-tension glaucoma. If no risk factors are identified, the treatment options for low-tension glaucoma are the same as for open-angle glaucoma.
Children are born with a defect in the angle of the eye that slows the normal drainage of fluid. These children usually have visible symptoms, such as cloudy eyes, sensitivity to light, and excessive tearing. Conventional surgery typically is the suggested treatment, because medicines may have unknown effects in infants and be difficult to administer. The operation is safe and effective. If surgery is done promptly, these children usually have an excellent chance of having good vision.
These can develop as complications of other medical conditions. These types of glaucoma are sometimes associated with eye surgery or advanced cataracts, eye injuries, certain eye tumors, or uveitis (eye inflammation). Pigmentary glaucoma occurs when pigment from the iris flakes off and blocks the meshwork, slowing fluid drainage. A severe form, called neo vascular glaucoma, is linked to diabetes. Corticosteroid drugs used to treat eye inflammations, and other diseases can trigger glaucoma in some people. Treatment includes medicines, laser surgery, or conventional surgery.
Early detection, through regular and complete eye exams, is the key to protecting your vision from damage caused by glaucoma. Following are the ways through which you can get your eyes examined for Glaucoma:
The tonometry test measures the inner pressure of the eye. Usually drops are used to numb the eye. Then the doctor or technician will use a special device that measures the eye’s pressure.
Ophthalmoscopy is used to investigate the inside of the eye, especially the optic nerve. In a darkened room, the doctor will magnify your eye by using an ophthalmoscope (an instrument with a small light on the end). It helps the doctor look at the shape and color of the optic nerve.
Perimetry is a procedure where the patient wears a patch over one eye and looks straight ahead at a bowl-shaped white area. At the same time, the computer presents lights in fixed locations around the bowl. The patient indicates each time he or she sees the light, which is why perimetry can provide a map of the visual fields. The type of vision loss associated with glaucoma is relatively specific, & perimetry can detect the typical visual-field defects of glaucoma disorder. The perimetry test is also called a visual field test.
Retinal Nerve Fibre Analysis/OCT Nerve fibre analysis is a newer method of glaucoma testing in which the thickness of the nerve fibre layer is measured. Thinner areas may indicate damage caused by glaucoma. This test is especially suitable for patients who may be considered to be a glaucoma suspect and also to indicate if a person’s glaucoma is progressively becoming worse. The OCT instrument utilizes a technique called optical coherence tomography which creates images by use of special beams of light. The OCT machine can produce a contour map of the optic nerve, optic cup and measure the retinal nerve fibre thickness. Over time this machine can detect loss of optic nerve fibres.
Pachymetry is the method of measuring the thickness of the cornea. Corneal thickness is critical because it can mask an accurate reading of eye pressure, causing doctors to treat you for a condition that may not really exist or to treat you unnecessarily when are normal. Actual IOP may be underestimated in patients with thinner CCT and overestimated in patients with thicker CCT. Pachymetry is a simple, quick, painless test With this measurement; your doctor can better understand your IOP reading, and develop a treatment plan that is right for your condition. The procedure takes only about a minute to measure both eyes.
Glaucoma is a chronic and progressive condition. Any vision loss that had occurred, before glaucoma was diagnosed, cannot be reversed. Glaucoma treatments at Dr. Dudhabhate Netralaya and Retina Centre include medicines, laser trabeculoplasty, conventional surgery, or a combination of any of these. While these treatments may save remaining vision, they do not improve sight already lost from glaucoma..
There is usually no visible scarring but at times the white of the eye can have any degree of redness
You may go home with an eye pad and shield, or just a shield. The pad can be removed after the first hour. The shield should be worn at night for the first week.
Your vision will normally be much better by Day 2. Sometimes there can be some blurring or misting in the eye, but this should improve over the course of the day. If you feel your vision is becoming more blurred, contact your hospital immediately.
