Vision Information - Common Eye Disorders
The most common eye concerns and changes range from slightly irritating to serious. We’ve explained some of the most asked eye health questions, including prevention and treatment of prevalent eye diseases.
A corneal transplant, or graft, is an operation in which part of the cornea is removed and replaced with a similar section from a donor eye. Patients often become quite anxious when told they need a corneal graft and worry about what this involves.
The cornea can be likened to a window that is in front of the eye. Light enters the eye through the clear cornea passing through the clear lens to focus on the retina at the back of the eye. If injury or disease damages or deforms the cornea, the path of light to the retina becomes distorted and vision is impaired.
A corneal graft is an operation in which part of the cornea is removed and replaced with a similar section from a donor eye.
The cornea assists in the focusing and transmission of light. If general eyewear and medication cannot help correct vision impairment due to injury or disease of the cornea, then a corneal graft may be performed to:
Improve your sight.
Repair a perforation if the cornea has ruptured.
After a corneal transplant, patients receive eye drops, pain medication, and antibiotic treatments to aid in recovery. An eye patch will be necessary to protect the eyes from harm, and the eye doctor must clear the patient to resume activities. It may take a while for the body to adjust to the new corneas and vision may take weeks to months to improve. Adjustments to stitches, glasses or contacts prescriptions, and laser surgery can help improve vision quality after a corneal graft. Follow up exams will be required frequently through the year after the transplant, then annually afterward.
Cornea transplants are generally safe and often successful, but as with any procedure, there are risks to discuss with your eye doctor. The most common risks of a corneal graft include:
Rejection of the cornea
Diabetes is a disease that affects many people and can have adverse consequences for the eye, including loss of vision and diabetic retinopathy. Blood sugar fluctuations can cause changes in the focusing of the crystalline lens within the eye and result in poor or blurry vision. It can also cause cataracts in young people and accelerate the development of cataracts in older people.
Diabetic retinopathy—a disease of the retina that occurs in response to elevated blood glucose levels—is a common cause of blindness in people between the ages of 30-65. At any one time, around 10% of people with diabetes will have retinopathy and require treatment. Diabetic retinopathy presents as changes in or leakage from the blood vessels within the eyes.
If your diabetes is rigorously controlled, the risk of contracting retinopathy can be reduced by 60% in type 1 (insulin-dependent) and 40% in type 2 (non-insulin-dependent) diabetes.
Though most diabetics who have had the condition for a long period will have some degree of retinopathy, eye checks can enable early diagnosis and treatment.
It is recommended that people with diabetes should have their eyes examined when diagnosed with the condition. Thereafter, regular annual comprehensive dilated eye exams are advised. Occasionally, an eye exam can reveal the early stages of diabetes due to the presence of damaged blood vessels that signal retinopathy—prior to a diabetes diagnosis.
Early detection and treatment is naturally the best. In the case of early detection, management of diabetes may prevent further damage. Advanced retinopathy may require laser surgery called photocoagulation to seal off leaking blood vessels and stop new blood vessel growth. This is not a cure, and will not restore lost vision, but it can prevent further damage. Though some discomfort is to be expected, the outpatient procedure is usually not painful because the retina does not contain nerve endings.
In some patients, the blood may leak into the vitreous humor and cause cloudy vision. The eye doctor may wait for it to dissipate on its own but, if necessary, a procedure called a vitrectomy, which removes blood that has leaked into the vitreous humor will be carried out.
If diabetic retinopathy has caused your body to form a cataract, it can be corrected surgically. Patients who have contracted glaucoma should see a glaucoma specialist.
Your eye care practitioner will provide comprehensive advice on the status of your condition and what to do about it.
Some people complain of shapes or shadows that drift across their vision. The form of these shapes varies and may sometimes appear as small dots or small irregularly shaped strands. These shapes are called floaters.
The vitreous is a jelly-like substance that fills the eye and, as it ages, protein strands called collagen become visible within it. When the eye moves, the strands gently swirl and give rise to the shifting shapes seen by patients. Flashes of bright white light can also occur that may indicate posterior vitreous detachment, which can lead to retinal detachment.
As a rule, you should not be concerned at seeing one or two floaters drift across your vision. But a sudden increase in the number of floaters, particularly if accompanied by white flashing lights, should raise an alarm and prompt an immediate visit to your eye doctor to examine for possible retinal detachment.
Floaters can be removed through an operation called a vitrectomy, which removes the vitreous. The procedure does carry significant risks which include retinal detachment and cataracts, and many eye surgeons are reluctant to recommend this surgery unless there is a threat to sight. There is no safe and effective medication, remedy, or cure for eye floaters—though they often become less noticeable over time. As long as there are no flashing lights or a sudden increase in the number of floaters, it’s just a normal part of aging. If eye floaters concern you, the best option is to speak with your optometrist.
When a separation occurs between the retina and the wall at the back of the eye, a retinal attachment develops. An operation is necessary to return the detached retina to its position.
Patients often describe the symptoms of a detached retina as a "curtain," "flashing lights," "something black," or a cobweb. In older people, this doesn't necessarily indicate a serious problem, but the sudden appearance of floaters or bright white flashes of light requires a comprehensive eye examination to rule out the presence of retinal holes or tears.
There are three types of retinal detachment: Rhegmatogenous, tractional, and exudative. Rhegmatogenous is the most common type of retinal detachment. Most retinal detachments develop because of a hole or tear in the retina that occurs when the retina becomes thin (in short-sighted people), or if the vitreous separates from the retina. An injury to the eye or a cataract operation may also cause it.
Retinal detachment can be repaired, and the success rate is high—but immediate treatment is necessary to prevent permanent vision loss. Treatment for a retinal tear or detachment may be done with a laser surgery or freezing treatment to secure the retina in place. Laser surgery, or photocoagulation, creates scarring to reconnect the retina, while the freezing treatment known as cryopexy uses cold to form a scar to hold the retina in place.
Some of the most common eye complaints are not concerning, like eye floaters. Others are serious conditions that need immediate attention from an eye doctor or specialist. Regular vision checks are important for maintaining your eye health, especially if you have a medical condition that can affect your vision. Permanent vision loss due to an eye disease or injury can be prevented or slowed with the proper, timely treatment. A comprehensive eye exam every one to two years, depending on risk and age, is an important step for maintaining the health of your eyes. Between eye exams, any notable change in vision or discomfort should be mentioned to your eye care provider.