Category Archives: Maryland

Mathematical model may lead to cure for dry eye

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May_Part 2_Ophthalmology

A treatment for dry eye – a burning, gritty condition that can impair vision and damage the cornea – could some day result from computer simulations that map the way tears move across the surface of the eye.

Kara Maki, assistant professor in Rochester Institute of Technology’s School of Mathematical Sciences, contributed to a recent National Science Foundation study seeking to understand the basic motion of tear film traversing the eye. “Tear Film Dynamic with Evaporation, Wetting and Time Dependent Flux boundary Condition on an Eye-shaped Domain,” published in the journal Physics of Fluid, is an extension of Maki’s doctoral research under her thesis advisor and co-author Richard Braun, professor in the University of Delaware’s Department of Mathematical Sciences.

“We’re hoping if we can understand better the basic dynamics of the tear film, then we can start to understand what goes wrong if you have dry eye and start to think about potential cures by studying simulations,” Maki said.

Dry eye is a common condition without a cure. Many causes, including the aging process, contribute to discomfort resulting from either a lack of tears or tears that evaporate too quickly. In the United States alone, nearly 5 million people age 50 and older suffer from dry eye, according to the National Eye Institute, part of the National Institutes of Health. Women are predominantly afflicted with the condition, with more than 3 million diagnosed with dry eye due to hormonal changes associated with menopause. Treatment to alleviate symptoms includes eye drops and temporary or surgical plugs to stopper tear ducts at the inner corners of the eyes and retain fluid.

To understand dry eye, Maki had to begin with the physics and chemistry of tears. Tear film consists of a layer of water sandwiched between an oily layer of lipids on the outside to prevent evaporation and an inner mucous layer to spread the water over the eye.

Kara developed a mathematical model to simulate the direction tear film travels when entering the eye from the lacrimal glands above the upper eyelid. Using the software program Overture, she recreated the flow of tears on the surface of an open eye, moving from the upper corner and draining through the ducts at the opposite corner.

“One thing we were able to find is that when your eyes are open, the tears get thin right along the edge of the eye, and that is referred to as the ‘black line,'” Maki said. “That has been seen clinically and can be reproduced in our simulations.”

The tears, Maki explains, climb up the eyelid and join a column of fluid that travels along the lids. Lower pressure sucks the fluid into the meniscus and away from the center, creating the black line and dry spots in the tear film that can compromise vision and irritate the cornea.

Maki saturated the eye with liquid to penetrate the black line. She wanted to know if the fluid would travel down the front of the eye and relieve the thinning of the tear film.

“We found that we had to really flood the eye in our simulations. The fluid would rather travel in the meniscus,” Maki said. “It splits traveling along the upper lid and the lower lid. We confirmed that blinking is necessary to stop this thinning from happening. Every time you blink, the tear film gets repainted on the front of your eye. It’s important to have smooth tear film for optical quality.”The next step for Maki and the team led by Braun is to simulate the dynamics of tear films in a blinking eye.

“The nice thing about having a model is that you can make unrealistic things happen,” Maki said. “For example, we can flood the eye and see where the tears go. Or we can look at what happens when the drainage holes are plugged. Where does the fluid go? You can start to explore these things in a safe way.”

http://www.medicalnewstoday.com/releases/277495.php

 

Picture courtesy to www.optometrystudents.com

 

 

 

GPs urged to ensure every squint is checked with a red reflex test to rule out eye cancer

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May_Part 1_Ophthalmology_Pediatrics

A children’s cancer charity is calling for all squints in babies and young children to be checked with a red reflex test to rule out eye cancer.

Figures released from the Childhood Eye Cancer Trust (CHECT) show that in 2013, over a quarter (26%) of babies and young children diagnosed with retinoblastoma (Rb) presented with a squint as a symptom.1 It is the second most common symptom after leukocoria (white pupillary reflex).

Joy Felgate, Chief Executive of CHECT said: “In our experience, some babies and young children are facing serious delays in receiving life-saving treatment as a result of parents either being told incorrectly that their baby’s squint is completely normal, or being given a non-urgent squint referral.”

Katy Bishop’s son Owen was incorrectly referred to a squint clinic at five months of age. His bilateral retinoblastoma was not diagnosed until he was ten months old. “Owen was too young to tell me his vision was failing, and his diagnosis was delayed five months because his squint was not properly checked. By the time he was diagnosed, he had a detached retina and was borderline for enucleation. Since then, he has had chemotherapy, cryotherapy and blood transfusions. We will never know the impact that five months’ delay has had on Owen’s future.”

As squints are common in babies up to the age of three months, the only way to determine whether this is a sign of a much more serious condition is to carry out a simple red reflex test, which is a non-invasive procedure, simply involving looking in the eye with a hand-held ophthalmoscope.

Mrs Felgate continued: “Non-urgent squint referrals can take months to come through, which can be a devastating delay for a child with undiagnosed eye cancer. Retinoblastoma is a very aggressive form of cancer and any delays in diagnosis can have a serious impact on treatment options. Currently more than 70% of children with unilateral Rb lose an eye to the disease.

“We are asking GPs to check every squint they see with the red reflex test.”

To promote this message CHECT has developed e-cards and an email campaign that GPs can share and forward on to colleagues. Copies of these are available from info@chect.org.uk.

Retinoblastoma is a fast-growing cancer of the eye affecting mainly 0 to 5-year-old children. Early detection of this aggressive condition is crucial to offer the child the best chance of saving their vision, their eyes and their life.

CHECT urges GPs to pay particular attention to children with

  • A recently onset squint
  • A white reflex (leukocoria) or an abnormal reflex in flash photographs
  • A change in colour to the iris
  • A deterioration in vision

Occasionally a retinoblastoma may present as a red, sore or swollen eye without infection. It is important to remember, however, that a child with Rb may appear systemically well.

Following a successful campaign by CHECT, most of these symptoms are now also listed in the latest versions of the Public Child Health Record (red book).

If any of the above symptoms are detected, a simple red reflex test can rule out retinoblastoma.

If you are unable to confidently rule out retinoblastoma with a red reflex test NICE guidelines state an urgent referral must be made to the local ophthalmology department stating ‘suspected retinoblastoma’. We recommend you call to alert them to the case and to find out how quickly urgent referrals are seen (in some cases it can be longer than two weeks).

http://www.medicalnewstoday.com/releases/276723.php

 

White Boys More Likely to Be Color Blind

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April_Part 2_Ophthalmology

 

Color blindness is not colorblind, as it appears to afflict Caucasian boys at three times the rate of African-American boys, according to a new study.

Among children 37 to 72 months of age, a total of 5.6% of Caucasian boys had color blindness compared with 1.6% of African-American boys, reported Rohit Varma, MD, MPH, of the University of Illinois at Chicago, and colleagues.

Asian boys had the second highest percentage at 3.1%, followed by Hispanic boys with 2.6%, they reported online in Ophthalmology.

The overall prevalence of color blindness was about 2% — translating to 59 boys and four girls out of 4,005 children who were able to complete the test. Color blindness is generally much more common in boys than in girls, since the red and green pigment genes involved in color vision are located on the X chromosome.

“To our knowledge, no previous population-based studies have investigated the prevalence of color vision deficiency in a multi-ethnic cohort of preschool children younger than 6 years,” researchers said.

Lore Nelson, MD, a pediatrician with the The University of Kansas Hospital in Kansas City, Kan., told MedPage Today that the study confirms what she and her colleagues see in clinical practice.

“The study is a reminder to screen more closely those groups with a higher incidence of color blindness,” she said.

The recommended age to begin vision screening — 3 years — is endorsed by the American Academy of Pediatrics, the American Academy of Ophthalmology, and the American Association for Pediatric Ophthalmology and Strabismus.

For their analysis, Varma and colleagues recruited the children from Los Angeles and Riverside counties in California as part of the population-based Multi-Ethnic Pediatric Eye Disease Study (MEPEDS).

When researchers compared older (61 to 72 months) with younger (37 to 60 months) children, they found no difference in prevalence of color blindness, nor did they find a difference between younger and older kids within any ethnic group.

They noted that testability was high by the age of 4 and increased linearly with age:

  • Ages 30 to 36 months: 17% were testable
  • Ages 37 to 48 months: 57%
  • Ages 49 to 60 months: 89%
  • Ages 61 to 72 months: 98%

The divide along ethnic lines is also reflective of findings in older children, Varma and colleagues pointed out. Data from the CDC’s National Health Examination Survey from the early 1960s found a 3.8% overall prevalence of color blindness in children ages 6 to 11 years(about 900,000 children affected). Among boys, race appeared to be significantly related to the presence of color blindness: 7.4% for whites versus 4% for blacks.

The corresponding study in children 12 to 17 years conducted in the latter half of the 1960s found an overall prevalence of 4.3% (again about 900,000 children affected), but the difference between white and black boys was not significant (7.7% versus 6.4%).

An earlier collaboration between MEPEDS and the the Baltimore Pediatric Eye Disease Study (BPEDS) also found ethnic differences regarding myopia and hyperopia.

Varma and colleagues noted that their study has some strengths, including “the large MEPEDS population-based cohort and the fact that standardized color vision testing was administered to the children by eye care professionals.”

Image courtesy of https://www.facebook.com/ResearchtoPreventBlindness

http://www.medpagetoday.com/Pediatrics/GeneralPediatrics/45100

 

 

 

What Is Glaucoma? What Causes Glaucoma?

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April_Part 1_Ophthalmology

Glaucoma is a disease of the eye in which fluid pressure within the eye rises – if left untreated the patient may lose vision, and even become blind. The disease generally affects both eyes, although one may have more severe signs and symptoms than the other.

 

There is a small space in the front of the eye called the “anterior chamber”. Clear liquid flows in-and-out of the anterior chamber, this fluid nourishes and bathes nearby tissues. If a patient has glaucoma, the fluid does not drain properly – it drains too slowly – out of the eye. This leads to fluid build-up, and pressure inside the eye rises. Unless this pressure is brought down and controlled, the optic nerve and other parts of the eye may become damaged, leading to loss of vision.

 

There are two main types of glaucoma, open angle andclosed angle (angle closure) glaucoma. The fluid in the eye flows through an area between the iris and cornea, where it escapes via the trabecular meshwork – “angle” refers to this area. The trabecular meshwork is made of sponky tissue lined by trabeculocytes. Fluid drains into s set of tubes, known as Schlemm’s canal, from which they flow into the blood system.

 

Closed Angle Glaucoma (acute angle-closure glaucoma) can come on suddenly, and the patient commonly experiences pain and rapid vision loss. Fortunately, the symptoms of pain and discomfort make the sufferer seek medical help, resulting in prompt treatment which usually prevents any permanent damage from occurring.

 

Primary Open Angle Glaucoma (chronic glaucoma) – progresses very slowly. The patient may not feel any symptoms; even slight loss of vision may go unnoticed. In this type of glaucoma, many people don’t get medical help until some permanent damage has already occurred.

 

Low-tension glaucoma – this is another form that experts do not fully understand. Even though eye pressure is normal, optic nerve damage still occurs. Perhaps the optic nerve is over-sensitive or there is atherosclerosisin the blood vessel that supplies the optic nerve.

 

Pigmentary glaucoma – this type generally develops during early or middle adulthood. Pigment granules, which arise from the back of the iris, are dispersed within the eye. If these granules build up in the trabecular meshwork, they can undermine the flow of fluids in the eye, leading to a rise in eye pressure. Running and some other sports can unsettle the granules, which get into the travecular meshwork.

Glaucoma has been called the silent thief of sight

 

Primary glaucoma – this means we do not know what the cause was.

 

Secondary glaucoma – the condition has a known cause, such as atumor, diabetes, an advanced cataract, or inflammation.

What are the signs and symptoms of glaucoma?

A symptom is something the sufferer experiences and describes, such as pain, while a sign is something others can identify, such as a rash or a swelling.

 

The signs and symptoms of primary open angle glaucoma and acute angle-closure glaucoma are quite different.

 

Signs and symptoms of primary open-angle glaucoma

  • Peripheral vision is gradually lost. This nearly always affects both eyes.
  • In advanced stages, the patient has tunnel vision

Signs and symptoms of closed angle glaucoma

  • Eye pain, usually severe
  • Blurred vision
  • Eye pain is often accompanied by nausea, and sometimes vomiting
  • Lights appear to have extra halo-like glows around them
  • Red eyes
  • Sudden, unexpected vision problems, especially when lighting is poor

What risk factors are linked to glaucoma?

A risk factor is something that raises the risk of developing a condition or disease. For example, obesity is a risk factor for diabetes type 2 – obese people have a higher risk of developing diabetes.

  • Old age – people over the age of 60 years have a higher risk of developing the disease. For African-Americans, the risk rises at a younger age.
  • Ethnic background – East Asians, because of their shallower anterior chamber depth, have a higher risk of developing glaucoma compared to Caucasians. The risk for those of Inuit origin is considerably greater still. People of African-American descent are three to four times more likely to develop the disease compared to American whites. Females are three times as likely to develop glaucoma as males.
  • Some illnesses and conditions – people with diabetes or hypothyroidism have a much higher chance of developing glaucoma.
  • Eye injuries or conditions – some eye injuries, especially severe ones, are linked to a higher glaucoma risk.Retinal detachment, eye inflammations and eye tumors can also cause glaucoma to occur.
  • Eye surgery – some patients who underwent eye surgery have a higher risk of glaucoma.
  • Myopia – people with myopia (nearsightedness) have a higher risk of glaucoma.
  • Corticosteroids – patients on long-term corticosteroids have a raised risk of developing several different conditions, including glaucoma. The risk is even greater with eyedrops containing corticosteroids.

Diagnosing glaucoma

Eye-pressure test – the doctor uses a tonometer, a device which measures intraocular pressure (pressure inside the eye). Some anesthetic and a dye is placed in the cornea, and a blue light is held against the eye to measure pressure. This test can diagnose ocular hypertension; a risk factor for open-angle glaucoma.

 

The doctor also measures corneal thickness, because it affects how the pressure inside the eye is interpreted.

 

Gonioscopy – this examines the area where the fluid drains out of the eye. It helps determine whether the angle between the cornea and the iris is open or blocked (closed).

 

Perimetry test – also known as a visual field test. It determines which area of the patient’s vision is missing. The patient is shown a sequence of light spots and asked to identify them. Some of the dots are located where the person’s peripheral vision is; the part of vision that is initially affected by glaucoma. If the patient cannot see those peripheral dots, it means that some vision damage has already occurred.

 

Optic nerve damage – the ophthalmologist (eye doctor) uses instruments to look at the back of the eye, which can reveal any slight changes which may also point towards glaucoma onset.

What are the treatment options for glaucoma?

Treatments involve either improving the flow of fluid inside the eye, reducing its production, and sometimes both. Damage caused by glaucoma is irreversible. Even the disease itself cannot be completely cured. However, regular check-ups and proper treatment can considerably slow down the progression of the disease, and even prevent further loss of eyesight.

 

Eyedrops – in the majority of cases, initial treatment includes eyedrops. Compliance is vital for best results and to prevent undesirable side effects – this means following the doctor’s instructions carefully. Examples of eyedrops include:

  • Prostaglandin analogues – these medications have prostaglandin-like compounds as their active ingredient. They increase the outflow of the fluid inside the eye. Some patients may experience reddening and stinging of the eyes, photophobia, some swelling around the rim of the eye, as well as darkening of the iris. The color of the eyelids may also change, and there may be blurred vision. Examples include Xalatan (latanoprost) and Lumigan (bimatroprost).
  • Beta blockers – these medication reduce the amount of fluid the eye produces. Some patients may experience breathing problems, hair loss, fatigue, depression, memory loss, a drop in blood pressure, and/or impotence. Examples of such medications include timolol, betaxolol and metipranolol.
  • Patients with certain lung conditions, such as emphysema or bronchitis may be prescribed a different medication. Diabetes patients who are taking insulin may also be prescribed an alternative drug.
  • Carbonic anhydrase inhibitors – these also reduce fluid production in the eye. Side effects may include nausea, eye irritation, dry mouth, frequent urination, tingling in the fingers/toes, and a strange taste in the mouth. Examples include brinzolamide and dorzolamide.
  • Cholinergic agents – also known as miotic agents. They help the fluids flow out of the eye. Side effects may include pain in and around the eye, myopia, blocked nose, some digestive problems, increased sweating and/or salivation, blurred vision, and ache around the eyebrows. Examples include pilocarpine and carbachol.

Sympathomimetic drugs – these reduce the production of fluid in the eye, as well as increasing their flow out of the eye. An example is dipivefrin, an epinephrine (adrenaline) compound. Some patients may experience painful and red eyes. Make sure your doctor knows if you suffer from heart disease or hypertension (high blood pressure).If eyedrops are not effective enough, the doctor may prescribe an oral carbonic anhydrase inhibitor. Side effects are less if they are taken during meals. Initial side effects may include tingling in the fingers and toes and frequent urination – however, after a few days they usually resolve. Much less commonly, there is also a risk of rashes, kidney stones, stomachache, weight loss, impotence, fatigue, and a strange taste when consuming fizzy drinks.

 

Surgery – if drugs don’t work, or if the patient cannot tolerate them, surgical intervention may become an option. The aim of surgery is usually to bring down the pressure inside the eye. Examples of surgery may include:

  • Trabeculoplasty – a high-energy laser beam is used to unblock clogged drainage canals, making it easier for the fluid inside the eye to drain out. This procedure nearly always reduces inner eye pressure. However, the problem may come back.
  • Filtering surgery (viscocanalostomy) – if nothing else works, including high-beam energy laser surgery, the patient may need a filtering procedure, usually a type of trabeculectomy. The surgeon creates an opening in the white of the eye and removes a small piece of the trabecular meshwork. This allows the eye fluid to leave through the opening.
  • Drainage implant (aqueous shunt implant) – this option is sometimes used for children or those with secondary glaucoma. A small silicone tube is inserted into the eye to help it drain out fluids better.

Acute angle-closure glaucoma – this condition is treated as a medical emergency. Pressure-reducing medications are administered immediately. A laser procedure is usually carried out which creates a tiny hole in the iris, allowing fluids to pass into the trabecular meshwork – this procedure is called an iridotomy. Even if only one eye is affected, the doctor may decide to treat both, because this type of glaucoma often affects the other eye too.

Complications of glaucoma

Loss of eyesight is the most common complication. The earlier a patient is diagnosed with glaucoma, the better his/her outlook.

 

Written by Christian Nordqvist

http://www.medicalnewstoday.com/articles/9710.php

What Is Glaucoma? What Causes Glaucoma?

Glaucoma is a disease of the eye in which fluid pressure within the eye rises – if left untreated the patient may lose vision, and even become blind. The disease generally affects both eyes, although one may have more severe signs and symptoms than the other.

 

There is a small space in the front of the eye called the “anterior chamber”. Clear liquid flows in-and-out of the anterior chamber, this fluid nourishes and bathes nearby tissues. If a patient has glaucoma, the fluid does not drain properly – it drains too slowly – out of the eye. This leads to fluid build-up, and pressure inside the eye rises. Unless this pressure is brought down and controlled, the optic nerve and other parts of the eye may become damaged, leading to loss of vision.

 

There are two main types of glaucoma, open angle andclosed angle (angle closure) glaucoma. The fluid in the eye flows through an area between the iris and cornea, where it escapes via the trabecular meshwork – “angle” refers to this area. The trabecular meshwork is made of sponky tissue lined by trabeculocytes. Fluid drains into s set of tubes, known as Schlemm’s canal, from which they flow into the blood system.

 

Closed Angle Glaucoma (acute angle-closure glaucoma) can come on suddenly, and the patient commonly experiences pain and rapid vision loss. Fortunately, the symptoms of pain and discomfort make the sufferer seek medical help, resulting in prompt treatment which usually prevents any permanent damage from occurring.

 

Primary Open Angle Glaucoma (chronic glaucoma) – progresses very slowly. The patient may not feel any symptoms; even slight loss of vision may go unnoticed. In this type of glaucoma, many people don’t get medical help until some permanent damage has already occurred.

 

Low-tension glaucoma – this is another form that experts do not fully understand. Even though eye pressure is normal, optic nerve damage still occurs. Perhaps the optic nerve is over-sensitive or there is atherosclerosisin the blood vessel that supplies the optic nerve.

 

Pigmentary glaucoma – this type generally develops during early or middle adulthood. Pigment granules, which arise from the back of the iris, are dispersed within the eye. If these granules build up in the trabecular meshwork, they can undermine the flow of fluids in the eye, leading to a rise in eye pressure. Running and some other sports can unsettle the granules, which get into the travecular meshwork.

Glaucoma has been called the silent thief of sight

 

Primary glaucoma – this means we do not know what the cause was.

 

Secondary glaucoma – the condition has a known cause, such as atumor, diabetes, an advanced cataract, or inflammation.

What are the signs and symptoms of glaucoma?

A symptom is something the sufferer experiences and describes, such as pain, while a sign is something others can identify, such as a rash or a swelling.

 

The signs and symptoms of primary open angle glaucoma and acute angle-closure glaucoma are quite different.

 

Signs and symptoms of primary open-angle glaucoma

  • Peripheral vision is gradually lost. This nearly always affects both eyes.
  • In advanced stages, the patient has tunnel vision

Signs and symptoms of closed angle glaucoma

  • Eye pain, usually severe
  • Blurred vision
  • Eye pain is often accompanied by nausea, and sometimes vomiting
  • Lights appear to have extra halo-like glows around them
  • Red eyes
  • Sudden, unexpected vision problems, especially when lighting is poor

What risk factors are linked to glaucoma?

A risk factor is something that raises the risk of developing a condition or disease. For example, obesity is a risk factor for diabetes type 2 – obese people have a higher risk of developing diabetes.

  • Old age – people over the age of 60 years have a higher risk of developing the disease. For African-Americans, the risk rises at a younger age.
  • Ethnic background – East Asians, because of their shallower anterior chamber depth, have a higher risk of developing glaucoma compared to Caucasians. The risk for those of Inuit origin is considerably greater still. People of African-American descent are three to four times more likely to develop the disease compared to American whites. Females are three times as likely to develop glaucoma as males.
  • Some illnesses and conditions – people with diabetes or hypothyroidism have a much higher chance of developing glaucoma.
  • Eye injuries or conditions – some eye injuries, especially severe ones, are linked to a higher glaucoma risk.Retinal detachment, eye inflammations and eye tumors can also cause glaucoma to occur.
  • Eye surgery – some patients who underwent eye surgery have a higher risk of glaucoma.
  • Myopia – people with myopia (nearsightedness) have a higher risk of glaucoma.
  • Corticosteroids – patients on long-term corticosteroids have a raised risk of developing several different conditions, including glaucoma. The risk is even greater with eyedrops containing corticosteroids.

Diagnosing glaucoma

Eye-pressure test – the doctor uses a tonometer, a device which measures intraocular pressure (pressure inside the eye). Some anesthetic and a dye is placed in the cornea, and a blue light is held against the eye to measure pressure. This test can diagnose ocular hypertension; a risk factor for open-angle glaucoma.

 

The doctor also measures corneal thickness, because it affects how the pressure inside the eye is interpreted.

 

Gonioscopy – this examines the area where the fluid drains out of the eye. It helps determine whether the angle between the cornea and the iris is open or blocked (closed).

 

Perimetry test – also known as a visual field test. It determines which area of the patient’s vision is missing. The patient is shown a sequence of light spots and asked to identify them. Some of the dots are located where the person’s peripheral vision is; the part of vision that is initially affected by glaucoma. If the patient cannot see those peripheral dots, it means that some vision damage has already occurred.

 

Optic nerve damage – the ophthalmologist (eye doctor) uses instruments to look at the back of the eye, which can reveal any slight changes which may also point towards glaucoma onset.

What are the treatment options for glaucoma?

Treatments involve either improving the flow of fluid inside the eye, reducing its production, and sometimes both. Damage caused by glaucoma is irreversible. Even the disease itself cannot be completely cured. However, regular check-ups and proper treatment can considerably slow down the progression of the disease, and even prevent further loss of eyesight.

 

Eyedrops – in the majority of cases, initial treatment includes eyedrops. Compliance is vital for best results and to prevent undesirable side effects – this means following the doctor’s instructions carefully. Examples of eyedrops include:

  • Prostaglandin analogues – these medications have prostaglandin-like compounds as their active ingredient. They increase the outflow of the fluid inside the eye. Some patients may experience reddening and stinging of the eyes, photophobia, some swelling around the rim of the eye, as well as darkening of the iris. The color of the eyelids may also change, and there may be blurred vision. Examples include Xalatan (latanoprost) and Lumigan (bimatroprost).
  • Beta blockers – these medication reduce the amount of fluid the eye produces. Some patients may experience breathing problems, hair loss, fatigue, depression, memory loss, a drop in blood pressure, and/or impotence. Examples of such medications include timolol, betaxolol and metipranolol.
  • Patients with certain lung conditions, such as emphysema or bronchitis may be prescribed a different medication. Diabetes patients who are taking insulin may also be prescribed an alternative drug.
  • Carbonic anhydrase inhibitors – these also reduce fluid production in the eye. Side effects may include nausea, eye irritation, dry mouth, frequent urination, tingling in the fingers/toes, and a strange taste in the mouth. Examples include brinzolamide and dorzolamide.
  • Cholinergic agents – also known as miotic agents. They help the fluids flow out of the eye. Side effects may include pain in and around the eye, myopia, blocked nose, some digestive problems, increased sweating and/or salivation, blurred vision, and ache around the eyebrows. Examples include pilocarpine and carbachol.

Sympathomimetic drugs – these reduce the production of fluid in the eye, as well as increasing their flow out of the eye. An example is dipivefrin, an epinephrine (adrenaline) compound. Some patients may experience painful and red eyes. Make sure your doctor knows if you suffer from heart disease or hypertension (high blood pressure).If eyedrops are not effective enough, the doctor may prescribe an oral carbonic anhydrase inhibitor. Side effects are less if they are taken during meals. Initial side effects may include tingling in the fingers and toes and frequent urination – however, after a few days they usually resolve. Much less commonly, there is also a risk of rashes, kidney stones, stomachache, weight loss, impotence, fatigue, and a strange taste when consuming fizzy drinks.

 

Surgery – if drugs don’t work, or if the patient cannot tolerate them, surgical intervention may become an option. The aim of surgery is usually to bring down the pressure inside the eye. Examples of surgery may include:

  • Trabeculoplasty – a high-energy laser beam is used to unblock clogged drainage canals, making it easier for the fluid inside the eye to drain out. This procedure nearly always reduces inner eye pressure. However, the problem may come back.
  • Filtering surgery (viscocanalostomy) – if nothing else works, including high-beam energy laser surgery, the patient may need a filtering procedure, usually a type of trabeculectomy. The surgeon creates an opening in the white of the eye and removes a small piece of the trabecular meshwork. This allows the eye fluid to leave through the opening.
  • Drainage implant (aqueous shunt implant) – this option is sometimes used for children or those with secondary glaucoma. A small silicone tube is inserted into the eye to help it drain out fluids better.

Acute angle-closure glaucoma – this condition is treated as a medical emergency. Pressure-reducing medications are administered immediately. A laser procedure is usually carried out which creates a tiny hole in the iris, allowing fluids to pass into the trabecular meshwork – this procedure is called an iridotomy. Even if only one eye is affected, the doctor may decide to treat both, because this type of glaucoma often affects the other eye too.

Complications of glaucoma

Loss of eyesight is the most common complication. The earlier a patient is diagnosed with glaucoma, the better his/her outlook.

 

Written by Christian Nordqvist

http://www.medicalnewstoday.com/articles/9710.php

 

 

Early detection of childhood eye cancer doesn’t always improve survival, prevent eye loss

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Oncology_Pediatrics_Ophthalmology

For the most common form of childhood eye cancer, unilateral retinoblastoma, shortening the time from the first appearance of symptoms to diagnosis of disease has no bearing on survival or stage of the disease, according to a study by researchers at Columbia University Mailman School of Public Health in partnership with the Hospital Infantil de Mexico. The results appear online in the journal Cancer Epidemiology, Biomarkers & Prevention.

Because retinoblastoma is easily detectable by shining a light into a child’s eye – often as a “cat’s eye” reflection revealed through flash photography – a number of countries, particularly resource-poor countries where the disease is more prevalent, have initiated education and screening programs, thinking that catching the disease early would lead to improved outcomes. This study is the first to follow a cohort of children with the disease over time and to look at the unilateral (one eye) and bilateral (two eyes) forms of the disease separately.

“Our study suggests that screening children for retinoblastoma may not improve outcomes for the majority of patients, particularly for the more common form of the disease affecting one eye,” says senior author Manuela A. Orjuela, MD, ScM, assistant professor of pediatrics and environmental health sciences at Columbia University Medical Center. “By the time the tumoris visible in the child’s eye, vision is infrequently salvageable, and removal of the eye is usually necessary to prevent spread of the disease.”

The research team followed 179 children with retinoblastoma in Mexico City and interviewed their parents about symptoms and socio-demographic factors. Physicians at the Hospital Infantil de México assessed disease stage using several validated methods. The researchers found that for unilateral disease, the lag-time between when parents first noticed the disease and when the children were diagnosed had no bearing on disease stage or survival. In the rarer bilateral disease, a longer lag-time was strongly associated with a more advanced stage and worse survival, but it did not predict the extent of disease involvement in the more affected eye. Lag-times averaged seven and eight months for unilateral and bilateral disease, respectively.

“Retinoblastoma is usually thought of as one disease. But there is good evidence that unilateral and bilateral retinoblastoma are distinct and progress in different ways,” says Dr. Orjuela.

“There is also significant variation in how tumors respond to treatment, no matter how soon we initiate therapy,” says first author Marco A. Ramírez-Ortiz, MD, chief of the department of Ophthalmology at the Hospital Infantil de México Federico Gomez, Mexico City.

Education and Housing Conditions Predict Outcomes

Intriguingly, the researchers found that stage and survival in both forms of retinoblastoma were predicted by the mother’s education level. Mothers with less formal schooling had children with significantly higher stage disease and significantly worse survival. Education was more important than the time needed for families to travel to the hospital or how many other young children needing childcare were in the household.

The child’s home environment may be another contributing factor. Children born in homes with dirt floors had more advanced disease than their peers with different housing conditions, even after taking family income into account, says Dr. Orjuela. “There is a possibility that these children were exposed to metal or some other toxin in the dirt, although confirming this hypothesis would be difficult, given the rarity of the disease.”

The finding on maternal education may offer a more fruitful intervention. “We may need to rethink the costs and benefits of screening programs and consider how to improve survival among children with less-educated parents,” says Dr. Orjuela.

“Although pathologic stage and tumor histology are important in the diagnosis and prognosis of retinoblastoma, social factors can help us gain new insights into how the disease progresses and, eventually, new ways to prevent and treat it,” says co-author Lourdes Cabrera-Muñoz, MD, Departamento de Patologìa, Hospital Infantil de Mèxico, Mexico City.

This work represents the latest finding from a longstanding multi-institutional collaboration involving co-authors Aurora Medina-Sansón and M. Veronica Ponce-Castañeda at the Hospital Infantil de México Federico Gomez, Mexico City; and Xinhua Liu at the Mailman School.

 

http://www.medicalnewstoday.com/releases/274226.php

Picture courtesy of wonderwoman.intoday.in

 

 

Bevacizumab – Treatment For Diabetic Macular Edema

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Ophthalmology

According to a study published Online First by Archives of Ophthalmology, bevacizumab appears to be more effective at treating diabetic macular edema (swelling of the retina) thanmacular laser therapy.

 

The researchers of the randomized controlled trial found that among participants with persistent clinically significant diabetic macular edema (CSME), bevacizumab showed to be effective at 12 months and was maintained through 24 months.

 

For the past 30 years, Modified Early Treatment Diabetic Retinopathy Study (ETDRS) macular laser therapy (MLT) has been the leading treatment for individuals suffering from CSME.

 

Although MLT lowers the risk of moderate visual loss, improved treatments have been sought as visual acuity only improves in less than 3% of patients (a 15-letter gain at 3 years).

 

Ranjan Rajendram, M.D., F.R.C.Ophth., of Moorfields Eye Hospital, London, and colleagues reveal the two-year outcomes of the BOLT Study.

 

The prospective randomized controlled trial involved 80 participants with CSME. Participants were randomly assigned to receive either injections into the eye (intravitreous bevacizumab) or modified ETDRS MLT.

 

The researchers found that at two years, the mean ETDRS best-corrected visual acuity in the bevacizumab group was 64.4 (Snellen visual acuity equivalent: 20/50) and 54.8 (Snellen equivalent: 20/80) in the MLT group.

 

Participants in the bevacizumab group gained a mean 8.6 letters, while participants in the MLT group lost a mean of 0.5 letters.

 

At 24 months, patients in the bevacizumab group gained a median of 9 ETDRS letters, compared with 2.5 ETDRS letters in the MLT group.

 

At two years, 49% of patients in the bevacizumab group gained 10+ ETDRS letters and 32 gained 15+ letters, versus participants in the MLT group 7% and 4%.

 

The researchers conclude:

 

“In conclusion, this investigator-initiated single-center study provides evidence for the longer-term use of bevacizumab in the treatment of persistent DME [diabetic macular edema].

 

Visual acuity benefit was maintained through two years with a reduced injection frequency in the second year despite the long duration of DME and multiple MLTs before entering the study. This finding will be reassuring to physicians charged with delivery of this relatively new treatment.”

 

Written By Grace Rattue

 

http://www.medicalnewstoday.com/articles/244008.php

Picture courtesy of www.treatmydme.com

 

 

Stop Smoking, Cut Cataract Risk

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Ophthalmology

The cataract risk associated with smoking slowly fell after ceasing tobacco use, although not to the level of a never-smoker, a Swedish population-based study showed.

Smoking more than 15 cigarettes per day was associated with 42% higher likelihood of a cataract surgery during 12 years of follow-up, Birgitta Ejdervik Lindblad, MD, PhD, of Örebro University Hospital in Örebro, Sweden, and colleagues found.

After having quit for 20 years, that risk had declined to a relative 21% above that of never-smokers, the researchers reported online in JAMA Ophthalmology.

The risk declined significantly with time (P<0.001), but “the higher the intensity of smoking, the longer it takes for the increased risk to decline,” the researchers noted.

Even lighter smokers with a fewer-than-15-a-day habit remained at significant risk 2 decades after quitting (rate ratio 1.13, 95% CI 1.04-1.24).

“These findings emphasize the importance of early smoking cessation and preferably the avoidance of smoking,” Linblad’s group concluded.

Plenty of prior studies have shown cataract and other ocular risks from smoking, so “eye care professionals should encourage people to stop smoking,” too, they recommended.

The presumed mechanism for this risk is that “smoking increases the oxidative stress in the lens by generating free radicals and reduces the plasma concentration of several antioxidants, such as ascorbic acid,” Lindblad and colleagues explained.

“Cigarette smoke also contains toxic metal ions, and cadmium can accumulate in cataractous lenses of smokers,” they added. “Cadmium may affect anti-oxidative lens enzymes such as superoxide dismutase and glutathione peroxidase, thereby weakening the defense against oxidative damage and hastening cataract development.”

Their analysis included 44,371 men in the Cohort of Swedish Men study ages 45 to 79 years, among whom 25% reported smoking and 39% had been smokers, based on questionnaire responses regarding smoking habits and lifestyle factors.

During 12 years of follow-up via the Swedish National Day-Surgery Register, and local registers of cataract extraction in the study area, an age-adjusted 13% had cataract extractions.

Limitations of the study included possible misclassification of self-reported smoking history, no assessment or control for sunlight or UV exposure, and lack of data on subtype of cataracts, although all were severe enough to cause visual impairment requiring lens extraction, “and therefore having the greatest clinical and public health importance.”

The study was supported by grants from the Swedish Council for Working Life and Social Research and the Örebro County Council.

The researchers reported no conflicts of interest.

http://www.medpagetoday.com/PrimaryCare/Smoking/43653

 

 

What is an Ophthalmologist?

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When you go to “get your eyes checked,” there are a variety of eye care providers you might see. Ophthalmologists, optometrists and opticians all play an important role in providing eye care services to consumers. However, each group has different levels of training and expertise; you should be sure you are seeing the right provider for your condition or treatment.

What is an ophthalmologist?

An ophthalmologist – Eye M.D. – is a medical or osteopathic doctor who specializes in eye and vision care. Ophthalmologists are specially trained to provide the full spectrum of eye care, from prescribing glasses and contact lenses to complex and delicate eye surgery. Many ophthalmologists are also involved in scientific research into the causes and cures for eye diseases and vision problems.

How is an ophthalmologist different from an optometrist and an optician?

Ophthalmologists are different from optometrists and opticians in their training and in what they can diagnose and treat. As a medical doctor, an ophthalmologist is licensed to practice medicine and surgery. An ophthalmologist diagnoses and treats all eye diseases, performs eye surgery and prescribes and fits eyeglasses and contact lenses. Ophthalmologists complete:

•  four years of college;

•  four years of medical school;

•  one year of internship;

•  three years, at least, of residency (hospital-based training) in the diagnosis and medical and surgical treatment of eye disorders.

An optometrist receives a Doctor of Optometry (OD) degree and is licensed to practice optometry, not medicine. The practice of optometry traditionally involves examining the eye for the purpose of prescribing and dispensing corrective lenses, screening vision to detect certain eye abnormalities, and prescribing medications for certain eye diseases.

An optician is trained to design, verify and fit eyeglass lenses and frames, contact lenses, and other devices to correct eyesight. They use prescriptions supplied by ophthalmologists or optometrists, but do not test vision or write prescriptions for visual corrections. Opticians are not permitted to diagnose or treat eye diseases.

How does an ophthalmologist become certified?

After four years of college and eight additional years of medical education and training, a certified ophthalmologist must pass a rigorous two-part examination given by the American Board of Ophthalmology.

http://www.eyecareamerica.org/eyecare/tmp/what-is-an-ophthalmologist.cfm