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Glaucoma Treatment & Surgery Options in Fortune Eye Care
Glaucoma is the most serious eyesight-threatening condition. It usually manifests as a painless, gradual loss of vision. The lost vision can never be recovered. However, medical or surgical treatment can prevent or retard further loss of vision.
Do Not Confuse Glaucoma with a Cataract
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).
Who is at a Risk for Glaucoma?
Anyone can develop glaucoma. Some people are at higher risk than others. They include:
Pain around the eyes when coming out from darkness (e.g., as soon as the person comes out of a cinema hall) Colored halo rings seen around light bulbs especially in the mornings and nights Frequent change of reading glasses, headaches, pain, and redness of the eyes Reduced vision in dim illumination and during nights Gradual decrease of side vision with the progression of glaucoma.
Types of Glaucoma
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 and no early warning signs. If open-angle glaucoma is not diagnosed and 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.
Low-Tension or Normal-Tension Glaucoma
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.
Secondary Glaucoma Types
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 neovascular 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.
Standard Investigation for Glaucoma
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, and perimetry can detect the typical visual-field defects of glaucoma disorder. The perimetry test is also called a visual field test.
Gonioscopy is used to detect which type of glaucoma you have. Once the surface of the eye has been numbed with eye drops, your eye specialist will place a special contact lens on your eye. This lens will allow your eye specialist to look at the eye’s drainage system and check if the angle where the iris meets the cornea is open or closed.
Newer Diagnostics for Glaucoma
Retinal Nerve Fibre Analysis/OCT
Retinal Nerve Fibre Analysis/OCT Nerve fiber analysis is a newer method of glaucoma testing in which the thickness of the nerve fiber 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 fiber thickness. Over time this machine can detect loss of
optic nerve fibers.
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.
Laser Peripheral Iridotomy – A Treatment for Acute Angle Closure Glaucoma
Patients with narrow, occlude-able angles or who have an attack of acute angle-closure glaucoma are treated with laser peripheral iridotomy (LPI).
Laser peripheral iridotomy involves creating a tiny opening in the peripheral iris, allowing aqueous fluid to flow from behind the iris directly to the anterior chamber of the eye. It typically results in resolution of the forwardly bowed iris and, thereby, an opening up of the angle of the eye. The narrow or closed-angle thus becomes an open-angle! Before the advent of the laser, surgery was necessary to create this bypass (surgical iridectomy).
The laser peripheral iridotomy procedure is completed in the office. Before the procedure, the pupil is often constricted with an eye drop medication known as Pilocarpine. Usually, a lens is placed on the eye (after topical anesthetic drops are applied) to control the laser beam better. The entire procedure takes only a few minutes. The lens is then removed from the eye, and vision will quickly return to normal. After the procedure, we may recommend anti-inflammatory eye drops for the next few days, and a post-operative visit will be scheduled.