Light rays enter the eye through the cornea where they are refracted (bent) and pass through the pupil to finally form a sharp focus or image on the innermost sensitive layer of the eye, the retina, just like in the camera. The retina then sends this information to the brain via the optic nerve and the brain perceives the final image. When the image is exactly formed on the retina and there is no power in the eyes, it is called Emmetropia.
Refractive errors are eye disorders in which the light is not properly refracted to a point focus on the retina and instead a blurred image is perceived.
How to diagnose?
The common method of measuring vision loss is the vision chart. Refraction and retinoscopy can help detect the actual error and the spectacle power.
What is Myopia (Nearsightedness)?
Nearsightedness or myopia is a condition in which near objects are seen clearly, but distant objects are not clear. This occurs due to light rays focus in front of the retina due to either longer eye ball or increased corneal curvature of a steep cornea. Myopia occurs in different degrees from minimal to extreme. The more myopic you are the blurrier your vision is at a distance and objects will have to be closer to you so you can see them clearly.
Nearsightedness is a common vision condition affecting nearly 20% of the Indian population. Commonly it starts in school-age children. Because the eye continues to grow during childhood, nearsightedness may increase up to the age of 18 to 21, which generally stabilizes by then. Recent studies showed that the nearsightedness could be hereditary as well as could be caused by too much stress on the eyes in terms of very close vision work in growing children. However, larger studies are still going-on to prove these theories.
A sign of nearsightedness is difficulty in seeing distant objects like TV screen and the child may want to watch it from very near or difficulty in seeing blackboard in the school, for which the child may want to copy from the student sitting next instead of looking at the blackboard. These children may have poor class work or class notes in spite of being regular and good at home work. A comprehensive eye examination is required in such cases to rule out nearsightedness.
It can be corrected by prescribing eyeglasses or contact lenses to optically correct nearsightedness, which you may only need to wear for certain activities, like watching TV or a movie or driving a car, or they may need to be worn continuously.
One thing that needs to be remembered is that in case of high myopia, there is a risk of retina getting detached, which would require a surgical treatment. Hence, a regular follow-up with eye doctor is a must.
What is Hyperopia (Farsightedness)?
Farsightedness, or hyperopia is a condition in which distant objects are usually seen clearly, but close ones are not clear. Farsightedness occurs if your eyeball is shorter than the normal or the cornea is less curved than normal or flat, so light entering your eye is focused behind the retina. It is usually inherited. A child is usually born with hyperopia and as the eye grows it reduces.
Common signs of farsightedness include difficulty in clearly seeing near objects, headaches, eye strain, and/or fatigue after close work. Although the hyperopia is not as common as myopia the common vision screenings, often done in schools, are generally ineffective in detecting this condition. A comprehensive ophthalmological examination is required in all those with above mention complaints.
In mild cases of hyperopia, patient may not need corrective glasses, as eyes may be able to compensate by working harder. In other cases, your ophthalmologist may prescribe spectacle or contact lenses to optically correct this condition.
What is Astigmatism (Distorted Vision)?
Astigmatism is a condition where the front surface of your eye, the cornea, is irregular in shape that is not perfectly round but more oval preventing the light to focus at one point on the back of your eye. the retina. As a result. the vision would be blurred at all distances. Astigmatism rarely occurs alone. It is usually accompanies myopia or hyperopia.
Most of astigmatism can be corrected with properly prescribed and fitted eyeglasses and/or contact lenses. However, higher astigmatism may be better handled by surgical means like astigmatic keratotomy or LASIK.
‘Wearing full correction of spectacles can damage the eyes’
Fact: For a child with a refractive error, glasses are a must, which correct the blurry vision. However, if you do
not wear a full correction the vision will continue to stay blurred, so it is imperative that full correction be worn to get a clear image.
‘Wearing eyeglasses will make you dependent on them’
Fact: Eyeglasses are a must to correct the blurred vision and to see clearly. One tends to prefer wearing the glasses in order to see well against uncorrected vision. It is actually this clear vision that one gets used to.
Corneal Collagen Crosslinking with Riboflavin – C3-R Treatment at Dhami Eye Care.
Corneal collagen crosslinking with riboflavin (C3-R) is the only non-surgical treatment that is proven to prevent the progression of keratoconus, and it may even be able to reverse the condition to some extent. Developed in Europe in the late 1990s, C3-R has now proven itself in international clinical studies and is approved throughout the European Union for the treatment of keratoconus. Dr G.S Dhami is pleased to offer corneal collagen crosslinking with riboflavin (C3-R) for his keratoconus patients as a treatment that is both effective and non-surgical.
- What is keratoconus?
- How is keratoconus treated?
- How does C3-R help?
- Who is suitable for C3-R?
- How is C3-R keratoconus treatment performed?
What is keratoconus?
Keratoconus is a progressive condition affecting the cornea of the eye. The cornea is the clear window in front of the eye. It is a curved structure. The precise shape of the curve allows it to act as a lens, projecting an image into the eye. The cornea is made up of bundles of protein called ‘collagen’. These bundles are normally held tightly together by chemical links between the collagen strands. This ensures that the shape of the cornea is constant. The problem with the keratoconic cornea is that the normal chemical links between collagen strands are deficient, causing the cornea to be unusually elastic. The pressure inside the eye then pushes the cornea into a distorted, conical shape. This spoils the quality of the image projected into the eye, and the vision becomes progressively blurred.
Keratoconus affects about 1 in 7000 people
How is keratoconus treated?
Glasses may be sufficient in the early stages of keratoconus, but contact lenses are needed when the cornea becomes so misshapen that glasses are no longer effective in correcting vision. Although soft contact lenses can sometimes be used, contact lenses for keratoconus are usually ‘hard’ gas-permeable lenses. Gas-permeable hard lenses are not always comfortable and may only be worn for a limited number of hours each day, but without them the vision is very blurred.
In some cases, the corneal shape becomes too distorted even for contact lenses to help. Also, scarring may develop, causing vision to become clouded. At this stage, a corneal transplant is usually needed. Corneal transplantation is quite major surgery and carries many risks.
The transplant stops the keratoconus progressing and provides a clear window into the eye. However, the shape of the cornea is usually far from perfect. Some people will see adequately with glasses after corneal transplantation, but most will still need contact lenses to see well.
Corneal transplants do not last forever and may have to be repeated every fifteen years or so.
This is why we offer C3-R at our Hospital. C3-R is a non-surgical keratoconus treatment method that can stop keratoconus from progressing to the stage where contact lenses or corneal transplantation becomes necessary.
How does C3-R help?
Corneal collagen crosslinking with riboflavin causes the formation of normal chemical links between the collagen protein strands in the cornea. This makes the cornea more rigid and can stop the keratoconus from progressing. The treatment may even cause the keratoconus to reverse to some extent.
C3-R may prevent the need for contact lenses if performed early on. Even where contact lenses are already needed, C3-R can eliminate the need for corneal transplantation. No other treatment for keratoconus can offer this; C3-R is unique.
Current evidence is that the effects of treatment are permanent.
Who is suitable for C3-R?
Anyone with progressive keratoconus is potentially suitable. Patients with very advanced keratoconus or whose vision is already spoiled by scarring will usually not be good candidates for the procedure.
The earlier the treatment is done, the better, but C3-R can still be beneficial decades after keratoconus has begun to develop. To find out how you might benefit from corneal collagen crosslinking with riboflavin (C3-R), contact our Hospital today.
How is C3-R keratoconus treatment performed?
At Dhami Eye Hospital, C3-R keratoconus treatment is a painless, out-patient procedure. It involves absorbing riboflavin eye-drops into the cornea and then bathing the surface of the eye in a very specific wavelength of light. The combination of the light and riboflavin causes chemical bonds to form within the cornea, increasing its rigidity and stability.
The whole process takes about one-and-a-half hours. After the procedure, a protective soft contact lens is worn for about 24 hours, and eye drops need to be instilled four times daily for five days and then twice daily for the next five weeks.
The procedure is extremely safe, and no sight-damaging complications have been reported.
A cataract is a gradual clouding of the eye’s natural lens. The formation of a cataract occurs during the normal process of aging. Although cataracts may affect people of any age, they are most common in older adults. Because cataracts form gradually, the symptoms are often difficult to spot. Perhaps you have noticed increased difficulty when driving toward the sun, find it harder to see traffic lights against a bright sky, or find it takes longer for your vision to return to normal after passing an oncoming set of bright headlights.
Symptoms include reduced depth perception, diminished color perception, annoying glare in sunlight, and poor night vision. Headaches, eye fatigue, burning, and watering of the eyes when exposed to bright light are also some other symptoms attributed to cataracts.
Types Of Cataract
There are many types of cataracts.
A change in the chemical composition of the lens causes most cataracts. The following are the various types of cataracts.
This is the most common type of cataract, comprising 80 percent of the total cataracts. It occurs in patients above the age of 50.
Cataracts in children are rare. They can be caused by infection of the mother during pregnancy, or they may be hereditary.
Which are the various types of Refractive Errors?
Eye injuries may cause cataracts in patients of any age.
Refractive errors are eye disorders and not diseases. These include myopia, hyperopia and astigmatism. Most people have one or more of them.
Eye diseases, like glaucoma, iritis, eye tumours, and diabetes may cause cataracts.
Prolonged treatment with steroid drugs, either for local (e.g., allergic conjunctivitis) or systemic diseases (e.g., asthma) may lead to cataract formation.
What causes cataract?
The normal process of aging causes the lens to harden and become cloudy (opaque). This is called age-related cataract and it is the most common type. It can occur anytime after the age of 40. In younger people cataract can result from an injury, certain drugs, long-standing inflammation or illnesses such as diabetes. Neonates can be born with this condition. This is called congenital cataract.
Other common causes are:
- Family history.
- Medical problems, such as diabetes.
- Long-term use of medications, such as steroids.
- Injury to the eye.
- Previous eye surgery.
- Long-term unprotected exposure to sunlight.
What are the symptoms of Cataract?
- Blurring of Vision – Cataract leads to a painless, progressive blurring or dimming of vision. The things may seem blurred around the edges, or your glass may seem dirty or scratched.
- Frequent change of glasses – Some forms of cataract lead to a change in refractive power of your lens and thus cause frequent changes in power of your glasses. Because of this, some patients may no longer need the reading glasses for near work, this phenomenon is known as ‘second sight’.
- Glare – Cataract may also lead to sensitivity to light and glare, especially in bright sunlight or while driving at night.
- Double Images – The cloudiness in the lens may occur in more than one place, so that the light rays that reach the retina are split, causing a double image.
- Change in color vision – Cataract may also cause change in color vision. As the cataract develops its center becomes more and more yellow, giving everything you see a yellowish tinge.
- Poor night vision.
- Needing a brighter light to read.
- Fading colours.
Are there different types of Cataracts?
There are mainly three types of cataract.
The Nuclear Cataract occurs in the center of the lens. This type is the most common form of cataract and is associated with the natural aging process.
The Cortical Cataract begins with spoke-like formation extending from the outside of the lens into the center. When the spokes reach the center, blurring and glare result in loss of vision. Diabetics commonly develop this type of cataract.
A Subcapsular Cataract develops very slowly and starts at the back of the lens. Symptoms may not appear until the opacity is well developed. Subcapsular cataracts are often found in patients with diabetes, high myopia, retinitis pigmentosa, and people taking steroids for extended periods.
What is the treatment for Cataract? Can it be cured by medicines?
Medications, eye drops, exercises or glasses cannot cause cataracts to disappear once they have formed. Surgery is the only way to remove a cataract.
When should I have the surgery?
If visual impairment interferes with your ability to read, to work, or to do the things you enjoy then you will want to consider surgery. Based on the needs and the examination findings, the patient and the ophthalmologist should decide together when surgery is appropriate.
Cataracts need not to be mature (‘ripe’) before removal. Today cataract surgery has the means to remove an immature cataract and a mature (‘ripe’) cataract.
What are the surgical options for cataract surgery, and which one is the best?
Today there are so many options in cataract surgery, e.g., routine extracapsular surgery with lens implant, phacoemulsification with a foldable or non-foldable lens implant, with or without stitches. The best procedure for a patient is usually the one with which his or her ophthalmologist feels the most comfortable, since these variations of cataract surgery are all quite effective. The patient should discuss the options with his or her ophthalmologist and the decision should be made on the basis of the requirements of the patient and expertise of the ophthalmologist.
What about pre-existing conditions?
Cataract surgery is beneficial even with the problems like macular degeneration, glaucoma and diabetes; the only limitation is that it may limit vision after surgery. If your eyes are healthy, the chances of restoring good vision following cataract surgery are excellent.
How is the surgery done?
After drops are used to numb the eye, a small, less than 3mm, incision is made. Special microsurgical instruments are used to break up and suction the lens fragments from the eye (phacoemulsification). The back portion of the lens capsule is left in place and polished for clarity. A small foldable intraocular lens will be inserted through the wound and unfolded in place of the natural lens. The incision is self-sealing so that no stitches are needed.
After cataract surgery, one may return almost immediately to all but the most strenuous activities. Medication must be administered as per the instructions of the surgeon. Your surgeon will tell you when you may return to work.
Conventional cataract surgery, which involves removal of the lens in one piece, results in an incision size of 10-12 mm and closure of this large incision with multiple stitches. This has been replaced with the modern technique of cataract removal [phacoemulsification].
What is phacoemulsification low stress surgery?
Phacoemulsification is a micro-incision technique of cataract surgery wherein an ultrasound probe breaks the cataract into tiny pieces and sucks them out. If a foldable implant is inserted the incision size is smaller (2.8 – 3.0 mm) as compared to an approximately 5 mm incision to accommodate a non-foldable lens. Both incisions are self-sealing and need no stitches. We will help you decide as to which lens should suit you best.
What are the benefits of low-stress phacoemulsification surgery for cataract?
The wound is smaller [resulting in faster healing and visual rehabilitation], the surgical time is reduced, and no stitches are required. There is minimal or no post-operative discomfort and a quick return to your normal routine.
What precautions do I need to take after surgery?
The only and most important precaution is that you are NOT SUPPOSED TO RUB YOUR EYE for at least a week after the surgery and do not go swimming for two weeks after surgery.
You can return to your normal activities after surgery. You may bend, stoop over, go up and down stairs, watch TV, read or work in the garden as usual. You may take showers and shampoo your hair.
Is it still necessary to wear eye glasses after the Cataract Surgery?
Nowadays, cataract patients who have intraocular lenses (IOLs) implanted during surgery may need reading glasses for close vision, but that’s about it. In fact, with the newer multifocal IOLs, even reading glasses are unnecessary. People who don’t receive IOLs wear contact lenses for distance vision, with reading glasses for close up. Or they may wear multifocal contact lenses for all distances. Rarely does anyone have to wear thick eyeglasses now.
How do I begin to have cataract surgery?
- Please fill and mail us enquiry form.
- Please also mail us your medical reports.
- Fix the date.
Toric Intraocular Lenses
When the natural crystalline lense of the eye is removed during cataract surgery, it can be replaced with a toric intracular lens (IOL) to correct astigmatism. Toric intraocular lenses are not multifocal lenses, but they can provide significantly improved vision for people suffering from moderate to high astigmatism.
Intraocular Lenses – Multifocal and Monofocal Lens Implant
Intraocular lenses – also called IOLs – come in two varieties: monofocal and multifocal intraocular lenses. IOLs are implantable lenses that replace the lens of the eye when it is removed during cataract surgery. Originally, IOLs were monofocal, or corrective of vision at one distance only, whether near, intermediate, or far.
Since they correct vision at just one distance, glasses are still needed, especially if the patient suffers from presbyopia (or age-related farsightedness). Newer, multifocal intraocular lenses will correct vision at multiple ranges, without the use of glasses or regular contact lenses.
AcrySof® ReSTOR® multifocal intraocular lenses are uniquely designed to improve vision at all distances, giving cataract patients the opportunity to experience life without glasses. ReSTOR® is modeled after microscope and telescope technology and focuses at both near and far distances, decreasing your dependency on glasses. Learn more about the AcrySof® ReSTOR® intraocular lens. For information visit www.acrysofrestor.com.
TECNIS™ intraocular lenses minimize glare and have been shown to allow significantly greater detail and contrast than traditional IOLs. TECNIS™ lenses have shown particular effectiveness in patients with reduced contrast sensitivity in low-light situations. Learn more about the TECNIS™ IOL. For more information visit www.tecnisiol.com.
Types of IOLs
If you are considering cataract surgery to replace the lens in your eye, you should discuss with your doctor which of the different types of IOL may work best for you. There are two main types of IOL to consider: monofocal and multifocal intraocular lenses.
A multifocal lens implant is designed for the correction of both near and far vision. Your brain must learn to select the visual information it needs to form an image of either near or distant objects, so multifocal lenses may require a period of adjustment. A person may adjust better to multifocal intraocular lenses if they are placed in both eyes.
The IOL Procedure
The IOL procedure is performed on an outpatient basis, usually requiring just a few hours to complete. The eye(s) is treated with anesthetic to limit any discomfort. A tiny incision is made at the edge of the eye and the cataract is removed. The monofocal or multifocal lens implant is then inserted through the same tiny incision.
Am I a Candidate?
Generally, to be a candidate for monofocal or multifocal intraocular lenses, a patient should have healthy eyes and a stable refraction. Patients must demonstrate at least six months of stable refraction prior to surgery. If you have noticed a blurring of your vision or other symptoms of cataracts, or if presbyopia has made reading small print a frustrating ordeal, you may be a good candidate for vision correction with intraocular lenses.
Risks of Intraocular Lenses
Although complications are rare, there are certain risks associated with intraocular lens surgery. Your ophthalmologist will perform a thorough examination of your eyes and will review your medical history to determine any factor or factors that may increase your susceptibility to IOL risks. Statistics show complications occur in less than 5 percent of cases.
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