Amblyopia (Lazy eye) is one of the most causes of vision problems in children, and affects approximately 2 to 3 children out of every 100.  Unless amblyopia (lazy eye) is diagnosed and treated early in childhood, the eye condition will persist into adulthood.  If left untreated, Amblyopia (lazy eye) will cause monocular visual impairment among children and adults.

Symptoms of amblyopia include:

• Poor visual acuity
• squinting to see
• Closing one eye to see
• Eye strain
• Headaches

There are several causes of amblyopia.  One of the causes is an imbalance in the positioning of the two eyes known as strabismus.  This can cause the eyes to cross or turn out.  This imblance can also occur when one of the eyes is more nearsighted, farsighted or astigmatic than the other eye.  Cataracts can also cause amblyopia (lazy eye).

Treatment of amblyopia (lazy eye) in children has been centred around making the children use the weaker eye.  This can be accomplished by using an eye drop called atropine in the stronger eye.  This treatment stimulates the vision in the weaker eye and assists the brain develop to manage vision more completely.  Another treatment of amblyopia (lazy eye) is to patch the stronger eye with an opaque patch.  This treatment takes place over a period of time and forces the children to use the eye with amblyopia.  This stimulates vision in the weaker eye and aids the brain development as well. 

There has been limited success in treated amblyopia in adults. Because of the difficulty in treating adults with amblyopia, it is important to diagnose and treat the eye condition in childhood.

• Eye Pain
• Eye Redness
• Blurred Vision
• Sensitivity to light
• Sensation of something in the eye
• Excessive tearing

People who exhibit these symptoms should consult with an eye care professional as Acanthamoeba Keratitis will eventually cause severe pain, possible vision loss and even blindness if left untreated.

Acanthamoeba Keratitis occurs primarily in individuals who wear contact lenses.  However, it is possible for anyone to develop this eye infection.  Patients who are generally diagnosed with Acanthamoeba Keratitis generally have exhibited certain behaviours associated with their contact lenses such as:

• Improper storage and handling
• Improper disinfection
• Swimming with lenses
• Showering with lenses
• Using a hot tub with lenses
• Coming into contact with contaminated water
• Previous history of trauma to the cornea

Once diagnosed by an eye care specialist, the infection can be treated with several eye medications that are available through prescription.  Diagnosis generally involves the existence of symptoms and a scraping of the eye or through microscopy.

People who wear contact lenses should take precaution when caring for their lenses and excerise proper hygene to reduce the risk of eye infections.  Regular eye exams are essential and given the widespread use of contact lenses, eye care professionals are aware of Acanthamoeba Keratitis.

Stargardt’s disease is thought to be inherited when both parents carry genetic mutations that causes the eye disease. Both parents can have the gene but not have the eye disease themselves. Stargardt’s disease is considered the most common form of juvenile macular degeneration.

Stargardt’s disease was named when Dr. Stargardt described this eye disease in 1909. Approximately 1 in 20,000 children over the age may be diagnosed with this eye disease and it is usually diagnosed before the age of 20. This disease affects both boys and girls equally.

With this form of macular degeneration, the macula and the surrounding retina are affected. Early in Stargardt’s disease, the macula may appear normal and over time change to allow diagnosis using a fluorescein angiography. With this test, a dye is injected into the arm and as the flow of this dye enters the eye it is observed. During the test, patients with stargardt’s disease has the flow of light blocked causing a “dark choroid” which is used to aid the diagnosis.

As the eye disease progresses, the retina appears to be “beaten metal” with small yellowish-white flecks (fundus flavimaculatus) in the peripheral retina. These may resemble drusen deposits that are noticeable in other forms of macular degeneration.

Children diagnosed with Stargardt’s Disease may experience a mild loss of visual acuity and a loss of sharpness of vision. Vision may appear somewhat normal in the early stages. As the eye disease progresses, there may be blind spots developing as the retina becomes more and more damaged. Images may appear and disappear.

As with other forms of macular degeneration, Stargardt’s Disease causes the loss of central vision. This is referred to as a central scotoma or blindspot in central vision. Patients may also develop abnormal color vision, photophobia (an abnormal intolerance of light) and night blindness.

There is currently no treatment for Stargardt’s disease.

Despite the importance of posterior staphyloma, little is known about them. This study aimed to study the characteristics of posterior staphyloma and how they may change with age.

The investigators analyzed 209 eyes of 108 consecutive patients with myopia of at least -8.0 diopters at their Tokyo clinic. The grade of staphylomas was determined from B-scan ultrasonographic images. The type of staphyloma was determined by ophthalmoscopy. The participants were divided into two groups: younger than 50 years and 50 years and older. The long-term progression of staphylomas was analyzed in nine patients who were followed up for more than 20 years.

The researchers found 90 percent of 209 eyes had a staphyloma. The prevalence of staphylomas and more advanced grades of staphylomas (> grade 2) were significantly higher in the older than in the younger patients.

The grade of the posterior staphyloma was determined from the B-scan and A-scan ultrasonographic images (Click to view figure). An elongated eye with a smooth scleral contour was graded as zero. A grade 1 staphyloma had a depth of 2 mm or less, a grade 2 staphyloma had a depth of 2-4 mm, a grade 3 staphyloma had a depth of 4-6 mm, and a grade 4 staphyloma had a depth of more than 6 mm. The higher grades of staphylomas were associated with more severe myopic retinal degeneration.

The type of posterior staphyloma was determined by the location, size, and severity (Click to view figure) and was classified according to the criteria of Dr Brian Curtin. The staphylomas were classified into 10 types: types I through V were primary staphylomas, and types IV through X were compound staphylomas. Type II staphyloma was the most prominent overall; however, in older subjects, the incidence of type II was decreased significantly, and that of type IX was increased significantly. The eyes with type IX staphyloma tended to have more severe myopic retinal degeneration than eyes with type II staphylomas. The long-term follow-up study demonstrated a progression from type II to type IX with increasing age.

The severity myopic macular degeneration was significantly higher in eyes with higher grade staphylomas. However, the prevalence of CNV (total CNV and active CNV) was not different among different grades of staphylomas in this study.

The researchers conclude that a staphyloma was present in 90% of the patients with high myopia, and the prevalence of staphylomas was significantly higher in older patients (96.7% in those 50 years of age and older) than in younger patients (80.7% in patients younger than 50 years).

The prevalence of grade 2 staphyloma (2-4mm) was significantly higher in patients older than 50 years than in those younger than 50 years. This indicates that not only the incidence of posterior staphyloma but also the depth of the staphyloma increased as the patient ages. The reason why the morphologic features of posterior staphyloma worsen with increasing age has not been clarified fully, but some authors have reported alterations in the composition of the sclera occur with age.

These results suggest that the morphologic features of staphylomas worsens as the patient ages. The progression from type II to type IX probably increases the mechanical tension on the macular area of highly myopic eyes, which then leads to myopic fundus lesions.

“This is a major breakthrough for eye cancer patients who are treated with radiation therapy and commonly develop radiation retinopathy,” said Paul T. Finger, MD, lead author of the study and director of Ocular Tumor Services at the New York Eye and Ear Infirmary. “Avastin reduces abnormal blood vessel growth, stops leakage in the eye and the patients wind up seeing better. This is a first.”

Until now, patients with inflammation or cancer of the eye’s choroid, retina, orbit and paranasal sinuses were confronted with a catch-22 in terms of treatment. Radiation therapy is the treatment of choice for most patients; but, it commonly causes a troubling side effect — radiation retinopathy.

Dr. Finger references in the study 6 patients who had plaque radiation therapy and developed radiation retinopathy, but he has now treated 28 patients successfully with Avastin, he says. “The drug improved or stabilized visual acuity in all cases by dramatically reducing blood vessel leakage and resultant swelling of the macula, the major causes of irreversible vision loss in radiation retinopathy,” he said. He also noted that, “before these Avastin findings, there was no effective treatment for macular radiation retinopathy.”

Avastin is a monoclonal anti-body which inhibits the formation of abnormal blood vessels by selectively blocking a substance known as vascular endothelial growth factor (VEGF). Avasitin (also called bevaciaumab) is used systemically (throughout the body) for some cancers and has been linked to the risk of stroke; but, in this new study, it was administered and stayed locally in the eye.

In February 2007, in a study published in The American Journal of Ophthalmology, Dr. Finger showed that treatment with Avastin had similar success in patients with radiation optic neuropathy.

The New York Eye and Ear Infirmary, the oldest specialty hospital in the Western Hemisphere, is the primary teaching hospital for the New York Medical College. It has approximately 142,000 outpatient visits annually and over 20,000 surgical procedures per year. It has one of the nation’s most extensive eye, ear, nose and throat clinics.

Source: The American Journal of Ophthalmology

Pinkeye gets its name from the fact that the white part of the eye and the inside of the eyelids becomes pink when a person is infected with this eye condition.  This eye condition may infect one eye and it is easily spread to the other eye if the disease is the infectious form.

When infected with pinkeye, there is generally no pain.  However, with this eye condition, the infected eye generally becomes itchy and may give the feeling that there is something caught in the eye such as an eyelash.

Causes of Pinkeye (Conjunctivitis)
Pinkeye may be caused by bacteria or a virus.  This type of pinkeye is typically referred to as infectious conjunctivitis.

Pinkeye may also be caused by allergies.  This type of pinkeyes is typically referred to as allergic conjunctivitis.

Pinkeye may also be caused by irritants that enter the eye.

Treatment of Pinkeye (Conjunctivitis)
The treatment for pinkeye (conjunctivitis) will vary based on the type of conjunctivitis diagnosed.  If the pinkeye is bacterial or viral, your doctor may prescribe antibiotic eye drops or cream.  If the pinkeye does not respond to the antibiotic treatment, the symptoms may be relieved by over the counter medications.  The eye condition may simply have to run its full course and the eye condition may clear itself over time.

If the irritation is allergic conjunctivitis, your doctor may prescribe antihistamines, decongestants, mast cell stabilizers, steroids and anti-inflammatory drops.  If the pinkeye is caused from another irritant entering the eye, your doctor may flush your eye to remove the irritant.

While pinkeye (conjunctivitis) is not a serious eye condition, caution and care must be given because this disease is contagious.  It can be passed from person to person through touch.  It is advisable to use separate hand  towels and face cloths while the pinkeye is present and to avoid placing your hands near your eyes in case you have come into contact with the bacteria or virus that has caused this eye condition.

The study found that people with high blood pressure had more than 3.5 times the risk of developing retinal vein occlusion than those without it. People with high cholesterol levels had an approximately 2.5-fold higher risk of retinal vein occlusion.

The findings come from an analysis of 21 previously published studies involving 2,916 people with retinal vein occlusion and 28,646 people without the condition. It found that 63.6 percent of patients with retinal vein occlusion also had hypertension, compared with 36.2 percent of people without the eye condition. High cholesterol levels were more than twice as likely to be found in those with retinal vein occlusion as those without (35.1 percent vs. 16.7 percent).

Diabetes also occurred slightly more often among those with retinal vein occlusion than among those without (14.6 percent vs. 11.1 percent).

“Accordingly, we recommend that an assessment of blood pressure and both fasting lipid and glucose levels be routinely performed in adults with any form of retinal vein occlusion,” the authors wrote.

The authors concluded that those who treat patients with hypertension, diabetes and high cholesterol should be as concerned with the health of the person’s eyes as they are with the health of the person’s cardiovascular system.

In September 2003, Investigative Ophthalmology and Vision Science reported a study in Rotterdam, The Netherlands demonstrating that high blood pressure may be associated with development of macular degeneration.  Similar studies have also concluded that elevated HDL but not total cholesterol is associated with an increased risk of AMD.  In fact, it was found that the use of statin drugs to treat high cholesterol was statistically significant in the development of advanced agerelated macular degeneration.  This analsys of the data also indicated that the use of these drugs were only linked to the development of the neovasular (wet) form of age related macular degeneration.

It is therefore imperative that people be more aware that all aspects of their health have dramatic affects on a persons well-being.  It is also important for health care professionals to be more aware of the relationships and interaction of various conditions on their patients.

Leber’s congenital amaurosis (LCA) is a rare eye disease that is inherited at birth whe nboth parents are carriers of a defective gene known to cause the disorder.  This eye disorder prevents the retina from processing light and it usually appears in people at birth or shortly after birth.

Researchers at the Children’s Hospital of Philadelphia injected a normal gene into a single eye of three patients suffering from LCA, leaving the other eye untouched.  Over the course of six-months, all patients (one 19, the other two 26) showed continual improvement.

According to Dr. Jean Bennett of the University of Pennsylvania and one of the studies authors, “All patients could read at least four lines on the eye chart.”  None of the patients injected with the gene showed any adverse effects from the treatment but showed considerable improvement in their eye disease.

In a parallel British study, only one of the patients responded favourably to the treatment.  That patient found that he could navigate through a maze more easily than he could prior to the treatment.  The other two patients showed no significant improvement in their vision.

The researchers hope that these advances in gene therapy could pave the way for finding better treatments and possibly even cures for other eye diseases such as age-related macular degeneration.

The results of both studies were published in the New England Journal of Medicine.

People with diabetes commonly suffer from an eye condition known as retinopathy.  In people suffering with retinopathy blood vessels in the eye may either swell and laek, or abnormal blood vessels may grow on the retina causing damage to the light sensitive area of the eye.

Retinopathy is recognized as one of the leading causes of blindness.  New research has now shown that retinopathy more than doubles the risk associated with developing heart disease.

Dr. Tien Y. Wong from the University of Melbourne in Autralia (and his colleagues) reported in the Journal of the American College of Cardiology that based on data analyzed data from 1,021 adults with type 2 diabetes who were without heart or kidney disease when the study began, 10.1% developed heart failure during the 9 year follow-up.  Of those studied, nearly 13 percent of the subjects did, however, have diabetic retinopathy at the beginning of the study.

Overall, 21.6 percent of patients with retinopathy developed heart failure compared with just 8.5 percent of those without retinopathy. After accounting for other factors that may have influenced the association, diabetic retinopathy increased the risk of heart failure by 2.2-fold.

Dr. Wong and his colleagues reported these findings in the Journal of the American College of Cardiology.

These findings could have important implications for clinicians because the detection of  retinopathy might now warrant comprehensive cardiac examinations throughout the life of the patient.

“Current guidelines already identify the need for routine screening for retinopathy in the diabetic patient. In addition to appropriate vision care,” they suggest that “the detection of retinopathy might now also warrant a fuller cardiac evaluation and closer follow-up to prevent the development of heart failure.”

SOURCE: Journal of the American College of Cardiology, April 22, 2008.

A cornea and external eye disease specialist at the Medical College of Wisconsin Eye Institute is breaking new ground in the treatment of eyes damaged by injury or disease by transplanting stem cells directly onto the cornea. The transplanted corneal stem cells divide and multiply, replacing missing cells and warding off a skin-like tissue (the conjunctiva) that in some cases invades the cornea and covers it like a blanket.

While the new procedure is still in its infancy, it has shown great promise in managing corneal disease for people who suffer limited vision or blindness. In the case of Michael Jent, a maintenance engineer who was severely burned on the job by the highly caustic chemical sodium hydroxide, the procedure has restored enough vision in one eye to enable him to walk without a white cane and even to drive.

“A stem cell is a cell that can go on to become, basically, a different cell,” said E. Lee Stock, MD, Medical College Professor of Ophthalmology, who is leading the work in corneal stem cell transplants at the Eye Institute. “Basic stem cells are embryonal cells that then go on to become all of the cells of the body.”

Stem cells have the remarkable potential to develop into many different cell types in the body. Serving as a sort of repair system for the body, they can theoretically divide without limit to replenish other cells. When a stem cell divides, each new cell has the potential to either remain a stem cell or become another type of cell with a more specialized function, such as a muscle cell, a red blood cell or – in this case – a corneal cell.

Good Transplant Territory
The cornea itself is a very successful tissue to transplant, consisting as it does of three clear layers and no blood vessels. As cornea transplants have become more common and “tried and true,” and are currently performed without the need to match donor cells to recipient cells, Dr. Stock and colleagues with expertise in transplanting other types of stem cells elsewhere in the body are moving into a new frontier by taking advantage of lessons learned and the fact that the cornea is such good territory for stem cell work.

Keeping the cornea clear of conjunctiva, the mucous membrane that lines the inner surface of the eye and eyelids, is the essential goal of corneal stem cell transplants.

“If you injure your cornea – for instance by a sodium hydroxide burn – the cells should start to grow and bring new corneal cells in,” notes Dr. Stock. “However, if the cells are destroyed, then the conjunctiva will grow over. Then, instead of having a clear cornea that you can see through, you have a cornea that is protected but doesn’t transmit light.

“What we have to do is to find a new cell to replace the damaged ones, but it has to be a stem cell or equivalent. We just take the same cells from a donor and we put them in place of the cells that have been damaged.”

Work in Progress
Corneal stem cell transplants are complicated and must often be repeated to achieve optimum results for the patient. As the procedure is refined, and as the quality and quantity of available stem cells increases, Dr. Stock said, outcomes will improve. Dr. Stock uses devices and techniques still in development to remove stem cells from donor corneas and then transplant them to the eyes of patients.

“In our early transplants we just took a few pieces and sutured them in place,” said Dr. Stock. “We got it to look more normal, but it still wasn’t cornea. What I started to do was, instead of taking little pieces, used a (specimen) that looks like a section of a tire that goes around that whole part of the eye – where the stem cells are – then took out the abnormal cells and put in the new ones. ”

Dr. Stock noted the work of Dr. Ed Holland in Cincinnati, who has applied stem cells in patients with aniridia. “Aniridia is a disease where the patient doesn’t have an iris; it’s hereditary, but also they don’t have normal corneal stem cells and they get vascularization (abnormal or excessive formation of blood vessels) of the cornea.

“In aniridia you get a clouded cornea in addition to all the other problems and you have stem cell deficiency,” he said. “What Dr. Holland suggested was doing the same thing as I described but instead of taking a ‘tire’ he did three halves to give more cells, and so we switched to that technique.”

The number of people who will benefit from corneal stem cell transplants is not very large as yet, but the difference the procedure can make in the lives of those candidates can be profound. “We’re averaging one (stem cell transplant) every month or two,” said Dr. Stock. “It’s effective to a certain extent. For instance, in Michael Jent’s case it’s hard to judge because he’d probably be totally blind without it. His vision is not great vision, but for him it’s the difference between being mobile and immobile. The vision isn’t as good as we’d like it to be, but he’s happy to be able to get around.”

Regarding the present and the promise of corneal stem cell transplantation, Dr. Stock is pleased with the progress so far. “On the whole it is successful, despite a lot of difficulty. I think the future is really great because, first of all, we collaborate with the stem cell people and they’re always making more inroads. They’ve been getting better cells, more concentrated cells, and there are other ways to do this even now – such as growing the cells in a culture first and then transplanting them. That’s not been proven yet, but has a lot of potential for improving things even more.”

Dan Ullrich
HealthLink Contributing Writer

Reprinted by permission of Medical College of Wisconsin HealthLink, 2004-07-01, www.healthlink.mcw.edu