What is Cataract
A cataract is a clouding of the lens in the eye that affects vision. Most cataracts
are related to aging. Cataract are very common in older people.A cataract can occur
in either or both eyes.
How can cataract affect my vision?
- 45 million in India are visually impaired
- 12 million totally blind
- ¼th of the world’s population of blind are in India
- Majority of them are needlessly blind
- 80% live in rural areas
Types Of Cataracts Include
- Age-Related Cataract: As the name suggests, this type of cataract develops
as a result of aging.
- Congenital Cataract: New born babies are sometimes born with cataracts as
a result of an infection, injury, or poor development before they were born, or
they may develop during childhood.
- Secondary Cataract: These develop as a result of other medical conditions,
like diabetes, or exposure to toxic substances, certain drugs, ultraviolet light,
or radiation.
- Traumatic Cataract: These form after injury to the eye.
Treatment For Cataract
There are two types of cataract surgery:
Phacoemulsification, or phaco: A small incision is made on the side of the
cornea, the clear, dome-shaped surface that covers the front of the eye. The tiny
probe inserted into the eye, this device emits ultrasound waves that soften and
break up the lens so that it can be removed by suction. Most cataract surgery today
is done by phacoemulsification, also called “small incision cataract surgery”
Extracapsular surgery: It have a longer incision on the side of the cornea
and removes the cloudy core of the lens in one piece. The rest of the lens is removed
by suction. After the natural lens has been removed, it often is replaced by an
artificial lens, called an intraocular lens (IOL). An IOL is a clear, plastic lens
that requires no care and becomes a permanent part of your eye. Light is focused
clearly by the IOL onto the retina, improving your vision. Some people cannot have
an IOL.
Diabetic Retinopathy
is caused by changes in the blood vessels of the retina. When these blood vessels
are damaged, they may leak blood and grow fragile new vessels. When the nerve cells
are damaged, vision is impaired. These changes can result in blurring of your vision,
haemorrhage into your eye, or, if untreated, retinal detachment.
Symptoms of Diabetic Retinopathy:
- Blurred vision
- Sudden loss of vision in one eye
- Seeing rings around lights
- Dark spots or flashing lights
The above symptoms may not necessarily mean that you have diabetic retinopathy.
However, if you experience one or more of these symptoms, examination is required.
Causes
People with untreated diabetes are 25 times more at risk for blindness than the
general population. The longer a person has had diabetes, the higher the risk of
developing diabetic retinopathy. Fortunately, with regular, proper eye care and
treatment when necessary, the incidence of severe vision loss has been greatly reduced.
Diabetic retinopathy can cause vision loss in two ways
- Macular Edema: is a condition where your retinal blood vessels develop tiny leaks.
When this occurs, blood and fluid leak from the retinal blood vessels and fatty
material (called exudate) is deposited in the retina. This causes swelling of the
retina and is called diabetic macular edema. When this swelling occurs in the central
part of the retina, also known as the macula, your vision will be reduced or blurred.
- Proliferative Retinopathy and Vitreous Hemorrhage: refers to the changes that occur
when new, abnormal blood vessels begin to grow on the surface of your retina. This
abnormal growth is called neovascularization. If these abnormal blood vessels grow
around your pupil, glaucoma can result from the increasing pressure within your
eye. These new blood vessels have weaker walls and may break and bleed, or cause
scar tissue to grow that can pull the retina away from the back of your eye. When
your retina is pulled away it is called a retinal detachment and, if left untreated,
it can cause severe vision loss, including blindness. Leaking blood can cloud the
vitreous-the clear, jelly-like substance that fills the back of the eye—and block
the light passing through the pupil to the retina, causing blurred and distorted
images. In more advanced proliferative retinopathy, diabetic fibrous or scar tissue
can form on the retina.
Treatment:
- Laser treatment should be offered for proliferative (stage three or four)
diabetic retinopathy and some cases of maculopathy.
- Intravitreal injections may be recommended if you have maculopathy.
- Vitreoretinal surgery may be needed if laser treatment is not possible because
retinopathy is too advanced.
Glaucoma: There is no cure for diabetic retinopathy, but laser treatment
(photocoagulation) is usually very effective at preventing vision loss if it is
done before the retina has been severely damaged. Surgical removal of the vitreous
gel (vitrectomy) may also help improve vision if the retina has not been severely
damaged. Sometimes injections of an anti-VEGF (vascular endothelial growth factor)
medicine or an anti-inflammatory medicine help to shrink new blood vessels in proliferative
diabetic retinopathy. Because symptoms may not develop until the disease becomes
severe, early detection through regular screening is important. The earlier retinopathy
is detected, the easier it is to treat and the more likely vision will be preserved.
Glaucoma refers to a group of related eye disorders that all cause damage to the
optic nerve that carries information from the eye to the brain. Glaucoma usually
has few or no initial symptoms. In most cases, glaucoma is associated with higher-than-normal
pressure inside the eye - a condition called ocular hypertension. But it also can
occur when intraocular pressure (IOP) is normal. If untreated or uncontrolled, glaucoma
first causes peripheral vision loss and eventually can lead to blindness.
Symptoms of Glaucoma?
The most people, there are usually few or no symptoms of glaucoma. The first sign
of glaucoma is often the loss of peripheral or side vision, which can go unnoticed
until late in the disease. This is why glaucoma is often called the "sneak thief
of vision."
Detecting glaucoma early is one reason you should have a complete exam with an eye
specialist every one to two years. Occasionally, intraocular pressure can rise to
severe levels. In these cases, sudden eye pain, headache, blurred vision, or the
appearance of halos around lights may occur.
If you have any of the following symptoms, seek immediate medical care:
- Seeing halos around lights
- Vision loss
- Redness in the eye
- Eye that looks hazy (particularly in infants)
- Nausea or vomiting
- Pain in the eye
- Narrowing of vision (tunnel vision)
What are the causes of glaucoma?
The increased pressure, called intraocular pressure, can damage the optic nerve,
which transmits images to the brain. If damage to the optic nerve from high eye
pressure continues, glaucoma will cause permanent loss of vision.
Can Glaucoma be prevented?
Glaucoma cannot be cured, but it can be controlled witheye drops, pills, laser procedures,
and surgical operations are used to prevent or slow further damage from occurring.
With any type of glaucoma, regular eye examinations are very important to detect
progression and to prevent vision loss.
Treatment
Glaucoma can be treated with eye drops, pills, laser surgery, traditional surgery
or a combination of these methods. The goal of any treatment is to prevent loss
of vision, as vision loss from glaucoma is irreversible. The good news is that glaucoma
can be managed if detected early, and that with medical and/or surgical treatment,
most people with glaucoma will not lose their sight.
Taking medications regularly, as prescribed, is crucial to preventing vision-threatening
damage. The different treatment options are as mentioned below:
- Eye Drops: It is important to take medications regularly and exactly as prescribed
to control eye pressure.
- Tablets: When eye drops don't sufficiently control IOP, tablets may be prescribed
in addition to drops. These pills, which have more systemic side effects than drops,
also serve to turn down the eye's faucet and lessen the production of fluid. These
medications are usually taken from two to four times daily. It is important to share
this information with all your other doctors so they can prescribe medications for
you which will not cause potentially dangerous interactions.
- Laser Surgery Laser surgery has become increasingly effective as an intermediate
step between drugs and traditional surgery though the long-term success rates are
variable. The most common type performed for open-angle glaucoma is called trabeculoplasty.
- Argon Laser Trabeculoplasty (ALT) -- for open-angle glaucoma The laser treats
the trabecular meshwork of the eye, increasing the drainage outflow, thereby lowering
the IOP. These lasers can be performed only two to three times in each eye over
a lifetime.
- Selective Laser Trabeculoplasty (SLT) -- for open-angle glaucoma SLT is a
newer laser that uses very low levels of energy. It is termed "selective" since
it leaves portions of the trabecular meshwork intact. For this reason, it is believed
that SLT, unlike other types of laser surgery, may be safely repeated.
- Laser Peripheral Iridotomy (LPI) -- for angle-closure glaucoma It is used
to make an opening through the iris, allowing aqueous fluid to flow from behind
the iris directly to the anterior chamber of the eye. This allows the fluid to bypass
its normal route. LPI is the preferred method for managing a wide variety of angle-closure
glaucomas that have some degree of pupillary blockage. This laser is most often
used to treat an anatomically narrow angle and prevent angle-closure glaucoma attacks.
Traditional Surgery
Trabeculectomy: When medications and laser therapies do not adequately lower eye
pressure, doctors may recommend conventional surgery. The most common of these operations
is called a trabeculectomy, which is used in both open-angle and closed-angle glaucoma’s.
- Drainage Implant Surgery Several different devices have been developed to
aid the drainage of aqueous humor out of the anterior chamber and lower IOP. All
of these drainage devices share a similar design which consists of a small silicone
tube that extends into the anterior chamber of the eye. This type of surgery is
thought to lower IOP less than trabeculectomy but is preferred in patients whose
IOP cannot be controlled with traditional surgery or who have previous scarring.
- Non-penetrating Surgery Newer non-penetrating glaucoma surgery, which does
not enter the anterior chamber of the eye, shows great result in minimizing postoperative
complications and lowering the risk for infection. However, such surgery often requires
a greater surgical acument and generally does not lower IOP as much as trabeculectomy.
Corneal Blindness: Corneal Blindness is a visual impairment that occurs from
the cornea becoming clouded, scarred or any other infection that ultimately affects
the transparency of cornea, making a person blind. It encompasses a range of eye
diseases, injuries or infections that damages the corneal tissues leading to permanent
blindness.
Corneal blindness can occur due to lesions affecting the cornea either in its entirety
or in parts. Some of the common causes of corneal blindness are:
- Deficiency of Vitamin A
- The aftereffects or viral, fungal or bacterial infections
- Congenital disease
- Eye Trauma
- Other traditional home remedies or medicines, which often damage eye instead of
relieving pain orimproving vision.
Different Types Of Corneal Disease
- Infections: Bacterial, fungal, or viral keratitis, as well as parasitic diseases
- Trauma: Abrasions or exposure to toxic chemicals
- Corneal dystrophies and degenerations: Fuchs' dystrophy and keratoconus
- Autoimmune disorders: Wegener's disease, rheumatoid arthritis, or lupus
- Nutritional deficiencies: Vitamin A deficiency
- Allergies: Vernal and atopic keratoconjunctivitis
- Growths: Pterygium or benign or malignant cancerous growths on the eye's
surface
There are three important elements to addressing corneal blindness: prevention,
treatment, and rehabilitation.
What Is The Treatment For Corneal Disease?
Treatment is tailored to the individual disease and the individual patient. Treatments
might include medications, laser treatment, or surgery, depending on the condition.