Glaucoma is one the most dreaded vision threatening condition. Glaucoma is a group of eye conditions which cause damage to the optic nerve. Vision loss due to Glaucoma is permanent. The vision loss in glaucoma is gradual, painless and progressive. However, early diagnosis and treatment can prevent progression of the disease.
Glaucoma and Cataract are two different eye conditions.
Most people confuse glaucoma and cataract. As even cataract presents with gradual, painless and progressive loss of vision. The vision loss due to cataract can be regained after cataract surgery.
A fluid called aqueous humour is constantly produced by the eye. A balance is maintained by the eye of the inflow and outflow of the aqueous. Like blood pressure in our body, the aqueous produces a pressure in the eye known as Intraocular Pressure (IOP). In Glaucoma the IOP is usually raised amd leads to damage of the optic nerve head.
Who is at a Risk for Glaucoma?
Anyone can develop glaucoma. Some people can be at higher risk than others. They include:
Over the age of 40 yrs.
Family history of glaucoma.
People with near sightedness (Myopia) for open angle type and far sightedness (hyperopia) for close angle type
Those suffering with Hypertension
People with Migraines
Common Symptoms of Glaucoma
Most of the times patients will not be aware if they are suffering from glaucoma until vision loss is significant. The symptoms of glaucoma include:
Open angle glaucoma-
Blind spots may be seen
Tunnel vision in advanced stages
Acute angle-closure glaucoma-
Redness in the eyes
Haloes around light
Types of Glaucoma
Corneal dystrophies are usually familial.
This the most common type of glaucoma. In this type the angle between the cornea and iris is open so it is called as Open Angle Glaucoma. In this type the IOP rises because the aqueous is not able to drain out the eye completely. Over the years the drainage canals in the trabecular meshwork get clogged up.
Most patients remain asymptomatic with no warning signs. If it is picked up in early stages, disease progression can be controlled. If it is not treated it will lead to gradual loss of vision.
This type of glaucoma is also known as narrow-angle glaucoma or acute angle-closure glaucoma. In this type the angle between the cornea and iris is closed. It usually presents as an acute attack with headache, pain, red eyes, blurring of vision and nausea
Low-Tension or Normal-Tension Glaucoma
In this type of glaucoma, the IOP is normal even then the optic nerve is damaged. Further reducing the IOP may be beneficial in some patients. In such patients systemic problems like low blood pressure must be ruled out.
Some children are born with defect in the angles. This leads to abnormal outflow and raised IOP. These children may have visible signs such as big eyes, cloudy cornea and excessive watering from the yes. Surgery is the treatment of choice in children as medicines may have unknown side-effects. If surgery is done early there ae chances that these children will have good vision.
Secondary Glaucoma Types
This type of glaucoma usually develops due some other intraocular or systemic pathology. These types of glaucoma can be following
Trauma to the eye
Treatment options include medicines, lasers and conventional surgery.
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Tests for Glaucoma
Early detection, compliance to treatment are most important in protecting the eye from glaucoma. The tests done in patient suffering from glaucoma are :
Tonometry is the test that measures the IOP of the eye. Applanation tonometry is the Gold standard to measure the IOP.
The eye is numbed with anaesthetic drops.
The eye is stained with fluorescein dye.
The IOP is measured with a special instrument.
The test visualizes the Optic disc. The doctor evaluates the shape, size and colour of the optic nerve head. Sometimes the doctor may put dilating drops in the eyes to dilate the pupil and then do an ophthalmoscopy.
This test is used to evaluate the field of vision of the patient. In this test one eye is tested at a time. The patient is asked to look in dome shaped instrument. The patient has to focus at a fixation target and at the same time look for any lights in the dome. Each time you see a light one has to press the trigger. The perimetry gives the details of the defect in the field of vision. Depending on the Visual field defects the progression of the disease is noted.
Gonioscopy is the test used to visualize the angles of the eye. This test helps to differentiate whether it is open angle or closed angle glaucoma. During this test the eye is numbed with eyedrops. The eye doctor places a special contact lens to visualize the angles of the eye.
Newer Diagnostics for Glaucoma
Retinal Nerve Fibre Analysis/OCT
Retinal Nerve Fibre Analysis/OCT is one of the latest modalities to test the severity of glaucoma. This helps in staging of the disease. This test measures the thickness of the nerve fibre layer. Thinner areas indicate damage caused by glaucoma. This test is very useful to detect glaucoma suspects. It also helps to know the progression of the disease. The OCT uses the technology known as Optical Coherence Tomography. The OCT maps the contour of the optic nerve, Optic cup and measures the thickness of the retinal nerve fibre layer.
Pachymetry is the test in which thickness of the cornea is measured. Corneal thickness plays an important role in the measurement of IOP. The pressure IOP fluctuates according to the thickness of the cornea. For thinner corneas the IOP is underestimated and in thicker corneas it is overestimated. Pachymetry is simple test. It is quick and painless. The pachymetry gives your eye doctor a better understanding of the IOP.
Laser Peripheral Iridotomy – A Treatment for Acute Angle Closure Glaucoma
Narrow / Occlude- able angles are treated with Laser Iridotomy.
In Laser peripheral iridotomy a tiny hole is made in the iris. This facilitates the flow of aqueous from behind the iris. Helps in opening the angle in angle closure glaucoma. In earlier days when lasers were not available a surgery was needed to do this procedure.
The laser peripheral iridotomy is a simple OPD procedure. Before the procedure, Pilocarpine eye drops are put in the eye to constrict the pupil. A lens is placed on the eye to focus the laser beam. Laser shots are given in the eye. The procedure takes only few minutes. After the procedure the lens is removed. Eyedrops will be prescribed to you for a few days.
Does laser peripheral iridotomy reverse glaucoma?
This procedure is usually done to prevent angle closure glaucoma. Most patients undergoing Laser PI do not have glaucoma. In those who have glaucoma this treatment will prevent further progression of the disease
Is the procedure painful?
The eye is numbed during the procedure. One may experience mild discomfort when the laser beam hits the iris There is usually no discomfort after the procedure.
What are the complications of this procedure?
Complications after laser iridotomy are rare. Occasionally there may bleeding in the eye, inflammation and transient rise in the IOP. Hence eyedrops are prescribed for a few days after the procedure.
Glaucoma Treatment in Pune at Indovision Cataract and Laser Eye Centre
Glaucoma is a progressive disease Any vision loss that occurred before the diagnosis of Glaucoma is permanent and cannot be reversed. At Indovision Cataract & Laser Eye Centre we offer a wide range of treatments for glaucoma- including medicines, laser trabeculoplasty, conventional surgery, and a combination ofthese treatments. While vision lost due to glaucoma cannot be recovered, treatment will prevent disease progression.
This is the most common treatment of glaucoma. Medicines, in the form of eye drops or tablets are prescribed. Some medicines reduce the production of the aqueous. Others reduce the pressure by improving the drainage of aqueous from the eye.
Glaucoma medicines are taken life long like BP tablets. Also you need to follow a strict schedule for the timings of the eyedrops.
Laser Trabeculoplasty :
Laser trabeculoplasty is a laser procedure that helps to improve the outflow of the aqueous from the eye.
Glaucoma Filtering Surgery :
Surgery is often the last treatment option. If eyedrops and lasers fail to control the IOP surgery may be considered. In this surgery a small piece of tissue is removed from the eye to create a new passage for the fluid to drain out from the eye.
Trabeculectomy surgery is performed on one eye at a time. Usually, the other eye is done four to six weeks later.