Can You Get Sunburned Eyes?

You know to slather on lots of sunblock before going out in the sun, and to keep applying it throughout the day. What about your eyes? Do you always wear a brimmed hat and sunglasses? Even on cloudy days? Can your eyes get sunburned?

The short answer is yes, you can get sunburned eyes, and just like your skin, it could come back and haunt you in the future.
 

eyes get sunburned
photo courtesy of Sarah DeRemer

Severely sunburned eyes, known as photokeratitis, is a result of prolonged exposure to the sun’s ultraviolet rays and can cause a burning sensation and blurred vision. Realize that these damaging UV rays do not just come directly from the sun, but also from the reflection of these rays from water and sand.

Symptoms of sunburned eyes include:

  • Eye pain
  • A  gritty feeling
  • Burning sensation
  • Red eyes
  • Swollen eyes and/or lids
  • Watery eyes
  • Blurred vision
  • Sensitivity to light
  • Glare and halos around lights
  • Headaches

These symptoms are temporary and should resolve on their own within 24 to 48 hours. If the symptoms last longer, see your eye doctor immediately.

While waiting for your eyes to recover you might want to:

  • Stay indoors and wear sunglasses to help with your increased light sensitivity.
  • Keep your eyes moist with preservative-free artificial tears.
  • Use OTC pain relievers to help with the pain and follow the recommended dosage.
  • DO NOT rub your eyes.
  • If you wear contact lenses, remove them immediately and stop wearing them until your eyes have returned to normal.
  • You may find that placing a cool, damp cloth over your closed eyes is soothing.

Just like with your skin, the UV rays do have a long-term effect on your eyes.  Sunlight can cause a slow deterioration of the cells in your eyes that could lead to eye diseases such as age-related macular degeneration and cataracts. Therefore it is best to limit you exposure to both direct and reflected UV rays.

The best ways to protect your eyes include wearing sunglasses that block 100% of the UV rays and a hat.  Not all sunglasses have UV protection, so make sure the ones you select do, and wear them whenever outdoors. Even on a cloudy day as UV rays penetrate clouds. For maximum protection consider wrap-around glasses to protect you from direct and indirect sunlight.  If you are participating in sports, goggles or glasses designed for your specific sport might be the best option. And don’t forget to wear a brimmed hat. It will not only protect you from indirect sunlight, it will also protect your face from sunburn.

Susan DeRemer

Susan DeRemer, CFRE
Discovery Eye Foundation

What You Should Know About Eye Color

One of the most common identifying factors of a person is their eye color. Here is what you should know about eye color.

eye color
We all know that eye color is genetic, depending on the genes we inherit from our parents. We used to think that brown eyes were “dominant” and blue eyes were “recessive,” but modern science has shown that eye color is not at all that simple. Human eye color originates with three genes, but there may be as many as 50 genes that have influence over eye color. Most people in the world have brown eyes, with the second most common colors being blue and grey. Green is the rarest color.

What gives you your eye color?

The color of your eyes depends on how much of the pigment melanin you have in your iris. The more pigment you have, the darker your eyes will be. Blue, grey, and green eyes are lighter because there is less melanin in the iris. Most Caucasian babies are born with blue eyes because melanin is not present at birth, but develops with age. However, by the age of three their eye color is determined.

A contributing factor is also your stroma, the front layer of the iris that contains fibers that scatter the light that is reflected outward. This helps to account for why you your eyes might appear to change color or intensify depending on what color you are wearing, amplifying the scattered light reflecting back.

Some children are born with eyes that are not the same color. This can be caused by faulty developmental pigment transport, trauma either in the womb or shortly after birth or a benign genetic disorder. However, because there could be a small chance of it indicating eye disease, such as Horner’s syndrome, it is suggested you have an early eye exam to make sure nothing serious is going on.

Can your eyes change color?

Contrary to popular opinion, your eyes do not change color based on your emotions. The iris is a muscle that expands and contracts to control the size of your pupil. It gets bigger in dim lighting and gets smaller in bright lighting. It also shrinks when you are focusing on close tasks, such as reading a book. Certain emotions can also change the pupil size, such as anger, grief or happiness. This can cause the pigments in the iris compress or spread apart, slightly changing the appearance of your eye color. Also because the pupil is black, your eyes appear darker. There are times when your eye color might darken slightly, such as puberty, pregnancy, and aging for 10%-15% of Caucasians with light-colored eyes.

What else does melanin do?

Besides giving our eyes color, melanin helps to protect them from the sun. Because they have less pigment, light eyes are much more sensitive to harmful UV rays from the sun and electronic devices than brown or black eyes. This makes UV protection even more important for babies and people with light-colored eyes.

Finally, because some people believe that the eyes are the windows to the soul, there are some superstitions about eye color. People with blue eyes are thought to have rich imaginations, people with green eyes have sharp minds, hazel eyes indicate a passionate soul and people with brown eyes are calm, but have underlying passion. What does your eye color say about you?

3/17/16

 

Susan DeRemerSusan DeRemer, CFRE
Vice President of Development
Discovery Eye Foundation

The Brain and the Eye – How They Work Together

The Brain and the Eye

The eye works like a camera. The iris and the pupil control how much light to let into the back of the eye, much like the shutter of a camera. When it is very dark, our pupils get bigger, letting in more light; when it is very bright our irises constrict, letting in very little light.

The lens of the eye, like the lens of a camera, helps us to focus. But just as a camera uses mirrors and other mechanical devices to focus, we rely on eyeglasses and contact lenses to help us to see more clearly.

The focus light rays are then directed to the back of the eye, on to the retina, which acts like the film in a camera. The cells in the retina absorb and convert the light to electrochemical impulses which are transferred along the optic nerve to the brain. The brain is instrumental in helping us see as it translates the image into something we can understand.

The Brain and the Eye

The eye may be small, but it is one of the most amazing parts of your body. To better understand it, it helps to understand the different parts and what they do.

Choroid
A layer with blood vessels that lines the back of the eye and is between the retina (the inner light-sensitive layer that acts like film) and the sclera (the outer white part of the eyeball).

Ciliary Body
The muscle structure behind the iris, which focuses the lens.

Cornea
The very front of the eye that is clear to help focus light into the eye. Corrective laser surgery reshapes the cornea, changing the focus to increase sharpness and/or clarity.

Fovea
The center of the macula which provides the sharp vision.

Iris
The colored part of the eye used to regulate the amount of light entering the eye. Lens focuses light rays onto the retina at the back of the eye. The lens is transparent, and can deteriorate as we age, resulting in the need for reading glasses. Intraocular lenses are used to replace lenses clouded by cataracts.

Macula
The area in the center of retina that contains special light-sensitive cells, allowing us to see fine details clearly in the center of our visual field. The deterioration of the macula can be common as we age, resulting in age related macular degeneration.

Optic Nerve
A bundle of more than a million nerve fibers carrying visual messages from the retina to the brain. Your brain actually controls what you see, since it combines images. Also the images focused on the retina are upside down, so the brain turns images right side up. This reversal of the images Is a lot like what a mirror does in a camera. Glaucoma can result when increase pressure in the eye restricts the flow of impulses to the brain, causing optic nerve damage and makes it difficult to see.

Pupil
The dark center opening in the middle of the iris changes size to adjust for the amount of light available to focus on the retina.

Retina
The nerve layer lining the back of the eye that senses light and creates electrical impulses that are sent through the optic nerve to the brain.

Sclera
The white outer coating of the eyeball.

Vitreous Humor
The clear, gelatinous substance filling the central cavity of the eye.

3/3/16

Susan DeRemerSusan DeRemer, CFRE
Vice President of Development
Discovery Eye Foundation

Pink Eye Tips and Prevention

pink eye
Pink eye is an inflammation or infection of the thin, clear covering of the white of your eyeball (the conjunctiva) and the inside of your eyelids. When the small blood vessels in the conjunctiva become inflamed they are more visible making the whites of your eye to appear pink. Also called conjunctivitis, it can affect one or both eyes.

Common symptoms of pink eye include:

  • Redness in the white of the eyeball(s) and or inner eye lid(s)
  • Increased tearing or discharge
  • Slightly blurred vision from discharge
  • Crusting of the eyelashes from the discharge that may prevent eyes from opening after sleep
  • Mild eyelid swelling
  • Itching or burning sensation
  • Increased sensitivity to light
  • Irritation or gritty feeling in your eye(s)

Make an appointment with your eye doctor if you notice and of the symptoms of pink eye. Some forms are highly contagious for as long as two weeks, so an early diagnosis could protect those around you from contacting the disease. If you were contact lenses, stop using them until directed by your doctor.

There are four general types of pink eye.

Allergic Conjunctivitis
This form is caused by eye irritants such as pollen, dust, animal dander and other environmental factors. It is not contagious. Treatment often includes applying a cool compress to your eyes and using allergy eye drops and artificial tears. In severe cases non-steroidal and anti-inflammatory medications may be prescribed.

Bacterial Conjunctivitis
This type is most often caused by staphylococcal or streptococcal bacteria, is highly contagious and can cause serious damage to the eye if left untreated. This is treated with antibiotic eye drops or ointments to speed up the healing process that can take one to two weeks. While you may see improvement after three to four days, the entire course of treatment needs to be used to prevent a recurrence.

Because this is so highly contagious here are a few things to remember so you don’t spread it to others or re-infect yourself:

  • Don’t touch your eye with your hands
  • Wash your hands frequently and thoroughly
  • Change towels and washcloths daily – and don’t share them
  • Change pillowcases often
  • Get rid of all eye cosmetics and personal care items such as eye creams – and don’t share them
  • Avoid swimming
  • Don’t reuse tissues when wiping your eyes, and throw them out immediately
  • Follow your eye doctor’s instructions related to your contact lens usage and care

Viral Conjunctivitis
This is the same type of virus associated with the common cold. Antibiotics will not work on a viral infection. Like a cold, the infection just needs to run its course which could take anywhere from a few days up to 2-3 weeks. It is also contagious like a cold, so follow the same instructions as listed above to not spread the infection.

Chemical Conjunctivitis
This can be caused by irritants like air pollutions, chorine in swimming pools or exposure to noxious chemicals. To treat this type of pink eye requires a doctor to carefully flush your eyes with saline and may require topical steroids. Acute chemical injuries are very serious and need prompt medical attention to avoid corneal scarring, intraocular damage, vision loss or the loss of an eye.

Of course the best way to deal with pink eye is not to get it. Here are some ways to protect yourself and others.
pink eye

2/24/16

Susan DeRemerSusan DeRemer, CFRE
Vice President of Development
Discovery Eye Foundation

Layers of the Retina

The retina at the back of the eye is essential for all vision. Each layer of cells in this tissue serves a specific purpose. As we prepare for Age-Related Macular Degeneration Awareness Month in February, a closer look at the layers of the retina and their function.

layers of the retina

Layers of the Retina

Choroid – This is made up of a layer of blood vessels that supply oxygen and nutrients to the retina. Defect in the CHM gene can cause choroideremia, leaky blood vessels can expand in the retina causing wet age-related macular degeneration (AMD) and diabetic retinopathy.

Retinal pigment epithelium – This is a single layer of cells that provide essential nutrition and waste removal for the photoreceptor cells. Accumulation of waste can lead to AMD and Stargardt disease.

Photorecptors – This is where the rods and cones are located that convert light into electrical signals. Rods help you with night and peripheral vision. Cones are more concentrated in the macula (the central part of the retina) and proved central and color vision. Death of the rods can cause vision loss called retinitis pigmentosa, while AMD is the loss of central vision.

Horizontal cells – These cells are connect to the photoreceptors that surround the bipolar connected photoreceptor cells and help the help integrate and regulate the input from multiple photoreceptor cells, increasing your visual acuity.

Bipolar cells – The dependence of each layer of the retina on each other is exemplified here. These cells take the electrical information from the photoreceptor cells and pass it along to other retinal cells.

Ganglion cells – These cells extend to form an optic nerve that conveys information to the brain and take the electrical information from the bipolar cells and process it to determine shapes, contrast and color. Glaucoma vision loss results from high intraocular pressure that affects the optic nerve, interrupting the signals to the brain.

 

Top 10 Articles of 2015

eye facts and eye disease
In looking at the many articles we shared with you in 2015, we found that your interests were varied. From the science of vision, eye facts and eye disease to helpful suggestions to help your vision.

Here is the list of the top 10 articles you read last year. Do you have a favorite that is not on the list? Share it in the comments section below.

    1. Rods and Cones Give Us Color, Detail and Night Vision
    2. 20 Facts About the Amazing Eye
    3. Understanding and Treating Corneal Scratches and Abrasions
    4. 32 Facts About Animal Eyes
    5. 20 Facts About Eye Color and Blinking
    6. When You See Things That Aren’t There
    7. Posterior Vitreous Detachment
    8. Can Keratoconus Progression Be Predicted?
    9. Winter Weather and Your Eyes
    10. Coffee and Glaucoma: “1-2 cups of coffee is probably fine, but…”

Do you have any topics you would like to see discussed in the blog? Please leave any suggestions you might have in the comments below.

1/7/16


Susan DeRemerSusan DeRemer, CFRE
Vice President of Development
Discovery Eye Foundation

Tear Film Health is Essential for People with Keratoconus

People afflicted with keratoconus (KC) are often obligated to wear contact lenses in order to obtain functional vision. Unfortunately, wearing contact lenses can have detrimental effects on the ocular surface and tear film layers over the course of decades, ultimately reducing lens tolerance. Therefore, any intervention prolonging the comfortable wear time of contact lenses should be aggressively pursued. The tear film covers the surface of the eye, provides lubrication and is the primary defense against foreign bodies and infection. Without a robust and healthy tear film, safe and comfortable contact lens wear is not possible. This article will describe the structure of the tear film and review simple remedies that can keep it healthy throughout life.

Tear Film Layers

The tear film is a complex, triple layered structure comprised of mucus, water and oil. The surface of the cornea and conjunctiva contain cells specialized to secrete a sticky mucoid substance. These so called goblet cells produce the mucin layer of the tears, which creates a “Velcro” type interface and allows the overlying watery component to stick to the ocular surface without washing away.

The bulk of the tear film is comprised of the watery, or “aqueous” layer which is secreted primarily by the lacrimal gland. This specialized structure is located near the eyebrow. This gland continuously releases small amounts of watery fluid that also contains enzymes and antibodies to help fight infection and wash away contaminants.

The lipid layer is the final, outermost layer of the tears. If the tear film is the first line of defense for the ocular surface, then the lipid layer is the first line of defense for the entire tear film and the ocular surface combined. Because of that role, it is extremely important and helps stabilize the tear film by preventing evaporation. This thin, lipid based layer is released by the meibomian glands, which are modified sebaceous glands that reside in the upper and lower lids. In each lid there are 20-30 glands. These glands open up onto the lid margin and through the action of a complete blink, release the lipid secretion to ocular surface which gets spread with the upward motion of the upper eyelid.

Each one of these layers contributes to the structure of the tear film, and a problem with any one of these structures (goblet cells, lacrimal gland or meibomian glands) will negatively impact the corresponding tear layer.

Tear Film
Image 1 -Layers of the tear film across the ocular surface & Meibomian glands of the eyelids. (Picture courtesy of TearScience™)

Tear Film Issues

Because the tear film is so thin, each individual component is necessary to maintain the integrity of the tears as a whole. When any layer of the tear film is deficient, the tear film becomes unstable and the ocular surface becomes irritated and can progress to developing classic symptoms of dry eye. This includes burning, stinging, redness, tearing, fatigue and contact lens intolerance.

Deficiencies in the mucin layer are uncommon, and are typically the result of chemical or thermal insult, or scarring. An aqueous deficiency, primarily from a lacrimal gland related etiology, is also relatively uncommon, and can arise from autoimmune and inflammatory causes such as Sjögren’s Syndrome. The most common reason for a poor tear film is linked with excessive evaporation of our tears due to a lack of sufficient lipid secretions from non-functioning or obstructed meibomian glands. It is understood that many factors contribute to why these glands stop performing optimally.

One factor has been linked to our habitual working environments. The compressive force exerted by the muscles of our eyelids that control blinking are essential for lipid secretion. However, the use of computers or wearing contact lenses has been shown to negatively impact our blinking habits, both by reducing the number of blinks and making blinks less complete. With an incomplete blink, the upper and lower lids do not make contact. The negative consequences of this are 1) the meibomian glands do not release their lipid contents, 2) the lower part of the eye is chronically exposed to the air, increasing evaporative stress and 3) dead skin cells accumulate on the lid margin which can clog the meibomian gland openings.

When increased evaporation of the tear film occurs chronically, the integrity of the entire ocular system becomes compromised over time and problems to the health of the eye become permanent attributes. This condition is known as Meibomian Gland Dysfunction or MGD and is linked with 86% of all dry eye sufferers.

Image 2 - Histology slide of a Meibomian gland with a terminal duct blockage
Image 2 – Histology slide of a Meibomian gland with a terminal duct blockage
Contact lenses have been shown in multiple studies to have a negative impact on the integrity of the tear film. To begin with, placement of a lens onto the eye divides the tears into two sections, referred to as the “post” (behind) and “pre” (in front) lens tear films.

The characteristics of the post lens tear film can differ depending on the type of lens that is worn. For example, soft lenses and scleral lenses have very little turnover of this post-lens tear film. This can cause issues related to the build up of toxic waste and bacterial elements that ultimately aggravate the corneal surface. Conversely, rigid gas permeable lenses are designed to have substantial tear turnover behind the contact lens with every blink.

The pre-lens tear film is also greatly affected by the type of lens material, as well as the interaction between the lid and the contact lens surfaces. Eye doctors know that without a healthy tear film, chances for contact lens intolerance increases. The rate of contact lens intolerance substantially increases as patients enter their fourth decade of life, primarily because of MGD caused by years of poor blinking habits.

Tear Film Care

Fortunately, simple interventions can prevent and/or limit the severity of MGD altogether or help to manage it once it occurs. Just like brushing and flossing one’s teeth can prevent gum disease, attention to complete blinking and lid margin hygiene can improve the tear film and prevent contact lens intolerance problems.

Because partial blinking is strongly linked with developing MGD, it is vitally important that the two lids touch when blinking. It is best to practice this several times throughout the day as well as when you are reading or using the computer.

Akin to flossing the teeth, it is also important to clean the lid margins with a Q-tip soaked in saline solution or a bit of mineral oil by gently brushing the Q-tip across the lid margin 10-20 times each night. It is easiest to get the lower lid.

Finally, performing warm compresses daily can provide heat to the Meibomian glands to soften the hardened oil that can plug the meibomian gland ducts. Warm compresses need to be done continuously for at least 10 minutes with consistent heat in order to attain a temperature that is sufficient to melt the oil that clogs the glands. We recommend folding 5-6 small towels or facecloths into a rectangular shape and wrapped together into a circular bundle, similar to the appearance of a cinnamon roll. The towels should be damp and moist, placed in a microwaveable safe dish with a lid and heated for approximately 1 minute and 50 seconds. After removal, wait a minute or two and then proceed to use the outermost cloth and cover the rest. Replace the first cloth after two minutes and grab the next outer most towel from the bundle, continuing this until all towels are used. In this way, the temperature can be adequately maintained for the full 10 minutes. The high temperatures applied to the lid are transferred to the cornea and very often cause temporary deformation, a phenomenon characterized by transient visual blur immediately following compress application. Therefore, it is vitally important, especially for patients with keratoconus, that pressure never be exerted onto the globe of the eye with a compress or massage administered to the lids of closed eyes after a compress.

It is becoming apparent that MGD is developing in patients at earlier ages. Because of this, the condition has likely been present for decades by the time the patient becomes symptomatic. It may take significant time and effort to rehabilitate not only the glands themselves, but also to reduce the resulting inflammation of the ocular surface.

Meibography is the technique used to image Meibomian glands. In chronic cases of MGD, we see abnormal changes to gland structure, in the form of atrophy or loss of gland tissue and/or dilation of glands where obstructed material causes glands to become widened. In severe cases, the prognosis for recovery is guarded.

The visual clarity that contact lenses provide for patients with keratoconus is incredibly important. But the ability to comfortably wear contact lenses is reliant on our body’s ability to provide a sufficiently thick protective tear film. Taking a small amount of time daily to attend to the lipid producing Meibomian glands by proper blinking habits, exfoliation of the lid margin with a Q-tip and warm compresses will help to extend the number of hours, and ultimately the number of years, that contact lenses can be safely and comfortably worn.

10/20/15

tear filmAmy Nau, OD
Korb and Associates, Boston, MA
Contact lens fitting for keratoconus, other ocular surface disorders and dry eye
 
 
 
 
 
 

tear filmDavid Murakami, MPH, OD, FAAO
Tear Science, Inc.
Researcher, Dry Eye

When Is The Best Time For Cataract Surgery?

As you age, cataracts become a concern prompting the question – when is the best time for cataract surgery?

There are decades worth of old wives tales floating around regarding cataracts that often lead to unnecessary fear and apprehension for many patients. These myths involve concepts such as “ripeness”, having to wear eye patches afterwards, danger in “waiting too long, etc. Just as the techniques of cataract extraction have changed over the decades, so have the indications to proceed to surgery.
best time for cataract surgery - people
Firstly, cataracts are a normal part of the aging process. Patients should not be alarmed if they are told that they are developing cataracts, even as early as their fifties. As we age, the natural clear lens inside the eye becomes progressively harder, darker, and cloudier. This dark, cloudy lens is what is referred to as a cataract. Cataracts develop at different rates for different people, and even between the two eyes of the same person. It typically takes many years for the lens to become cloudy enough to impact the clarity of vision. There are many different types of cataracts depending of what area of the lens becomes cloudy, but the typical cataract related to normal aging results in a relatively uniform cloudiness with a denser central core, and is referred to as “Nuclear Sclerosis”. Other varieties of cataracts tend to grow more quickly, are relatively uncommon, and often result from certain conditions other than typical aging.
best time for cataract surgery
Regardless of what type of cataract the patient has, the treatment is the same: cataract extraction with an implant of an intraocular lens. There have been great advances in lens design over the years, and they now result in excellent, stable, predictable vision for the remainder of the patient’s lifetime and do not typically need to be changed once implanted.

Cataracts result in different symptoms that may be more of less relevant to a specific person’s needs, such as:

  • Glare with bright lights
  • Difficulty with fine print
  • Difficulty following the golf or tennis ball
  • Impairment in night driving
  • Difficulty with seeing street signs
  • Seeing the score or small print on the television
  • Fine visual tasks such as threading a needle, etc.

Although cataract surgery is an incredibly successful procedure with only about a 1-2% risk of complications, it still DOES have some risk. Therefore, cataract surgery should only be undertaken when there is something to gain. In other words, the BENEFITS MUST OUTWEIGH THE RISKS. This means that if your symptoms are mild and are not interfering with your activities of daily living, it is not time to accept the risks of surgery. Once your visual impairment progresses to the point that YOU feel your activities of daily living and enjoyment are impaired, this is the time to proceed to surgery. This threshold is very different between people. Some people feel impaired with vision of 20/25, and others still function within their scope of usual activities until they are 20/100! The best first-step in determining if it is time for your surgery is to get an up-to date refraction. This means a detailed check for new glasses. Often, cataract development will change a person’s glasses prescription, and updating this can improve the visual symptoms for months to years. When a new glasses prescription no longer improves the sight adequately, this is when surgery is indicated.

For the most part, putting off cataract surgery does not impact the final outcome. It will not harm you or your eye to leave the cataract alone until you are ready. There are of course certain exceptions to this rule, such as in Fuchs’ dystrophy, pseudoexfolation, untreated narrow-angle glaucoma, and some others. However, these are relatively rare conditions that your doctor will speak to you about if you have any of these diagnoses.

In summary, the time to proceed to cataract surgery is something that you as the patient determine. YOU assess your lifestyle needs and your vision performance within your scope of activities. When you feel you are impaired in these activities, the benefits will outweigh the risks, and it’s time to take them out. You should not feel any pressure to urgency in this process.

Once you have determined you are ready to have cataract surgery, your surgeon will discuss with you your options for intraocular lens implantation including astigmatism neutralizing lenses, standard distance or near-vision lenses, multiple focal distance lenses, accommodating lenses, and others. The current standard approach for cataract surgery is called “phacoemulsification” and uses ultrasound technology to remove the cataract. There are also laser devices that assist in making the incisions and breaking up the lens, which many surgeons now employ in addition to the phacoemulsification. In general cataract surgery only takes a few minutes, is performed with topical anesthesia, is pain-free, and has a very short recovery time. No pirate-patches are used these days! Most patients are very happy with the results, but this requires adequate discussion with the surgeon prior to the procedure to best assess the needs of the individual patient. A well- informed patient who participates in their care results in the best outcomes!

6/18/15

Sameh Mosaed, MD best time for cataract surgerySameh Mosaed, MD
Director of Glaucoma Services, Gavin Herbert Eye Institute, UC Irvine
Associate Professor, Cataract and Glaucoma Surgery, UC Irvine School of Medicine

Cataract Prevention

The more you know about cataracts, the easier it is to focus on cataract prevention.

What is a cataract?

At birth, with rare exceptions, most of us arrive in the world with a clear crystalline lens within each eye. The pathway of our visual images start with light passing through the cornea (the clear front window of the eye), through the pupil (the opening in the center of the iris, or colored portion of the eye) and through crystalline lens which functions to focus light onto the center of the retina (the film of the eye). cataract preventionThe retina, via the optic nerve, will then transmit visual images to the brain. When the crystalline lens becomes opacified (cloudy), this system becomes disrupted, and vision becomes impaired. Opacification of the crystalline lens is called “cataract”, and there are many variations in appearance and type and many causes and can present at any age. The word cataract originates from the Greek word “cataracta”, which means waterfall. The ancient Greeks used this term as they noticed a similarity in the appearance of the white opaque rushing water of a waterfall and the appearance of a white mature cataract.

To understand the different types of cataracts and causes, it is important to understand the anatomy of the lens. Using a metaphor, the lens anatomy can be compared to a Peanut M&M candy™. There is an outer candy coating (the lens capsule), a chocolate layer inside (the lens cortex), and a peanut in the center (the lens nucleus).

The most common cause of a cataract is an age related nuclear clouding which is due to long term accumulation of metabolic and oxidative waste products within the lens and possibly UV-B/Sunlight light exposure. Cortical clouding (within the cortex of the lens), due to similar causes, is also a common cause of an age related cataract.

Cataracts can occur earlier in life with poorly controlled diabetes resulting in cortical and nuclear cataract. Patients who are exposed to steroid medications in any form (orally, topically as eye drops, skin creams etc.) are at an increased risk to develop a posterior subcapsular (PSC) cataract which occurs on the posterior lens capsule. PSC cataracts can have a much more abrupt and earlier onset in life than nuclear or cortical cataract. Smoking has also been known to predispose patients to formation of a PSC cataract. Other less common varieties of cataract can occur with any trauma to the eye or even present at birth as a congenital cataract with a large variety of causes.

What can be done to prevent cataracts?

I often joke with patients that a cataract is such a common occurrence that just like birth, death, and taxes, it is an issue we must all face at some juncture in life (hopefully later than earlier). I am often asked if there are any dietary measures or vitamin supplementation to reduce the formation of a cataract, however this is not as well studied as the use of vitamins in the prevention of macular degeneration. Several scientific epidemiological studies following populations over many decades have shown some merit however that using multivitamins regularly (Vitamin B6 and B12, Vitamin C, beta carotene, antioxidants and possibly lutein and zeaxathin) can reduce the degree of lens opacification over time. As with all medications, you should consult with your physician before deciding to use any vitamin supplementation to clarify if you have any contraindication to using them.

There is conflicting evidence regarding the role of UV-B exposure in sunlight as a causative agent for cataracts. There is some support that using sunglasses on a regular basis to block UV-B light may help to reduce cortical cataract formation. Smoking cessation can also help to reduce the formation of cataract. If a patient is diabetic, strict blood sugar control is also an important measure to reduce the formation of a cataract. If possible, reducing or avoiding the use of steroid medication can reduce the formation of a PSC cataract.

What can be done if a cataract is worsenening and glasses cannot help improve vision significantly?

If you are experiencing gradual painless loss of vision, you should consult with your ophthalmologist as cataract can be a common cause. If you are found to have cataract formation, there is generally a shift in the glasses prescription in the early stage. Having your glasses prescription checked to see if your vision can be improved with glasses is the first step in determining how significant your cataract has become. If glasses are not able to sufficiently improve your vision and your daily activities are affected by the decrease in vision your experience, you may be a candidate to have cataract surgery.

Modern cataract surgery has improved a tremendous degree compared to decades earlier. It is the most common and successful surgery in the world, and is typically performed on an outpatient basis with topical anesthetic and often without any sutures or eye patch. Prior to surgery the pupil is dilated, and once in the operating room, a small self-sealing incision is made on the side of the cornea. The surgeon then makes a circular opening in the anterior lens capsule (the candy coating of the peanut M&M), and uses an ultrasound instrument to emulsify and vacuum out the nucleus (the central peanut), and remove the cortex (the chocolate layer). The inside of the lens capsule is polished and an intraocular lens is folded and introduced into the eye through the corneal incision and seated into the remaining lens capsule to conclude the surgery.

Prior to surgery, measurements are taken to determine the power of lens necessary to achieve the best vision after surgery based on the curvature of the cornea and anterior-posterior length of the eye. Intraocular lenses (IOLs) can potentially have several features depending on a patient’s needs. The most common IOL used is a monofocal lens, which does not typically require an additional out of pocket expense. This lens is chosen to have a point of focus either for distance vision (driving, TV) or near vision (reading), but not both. Typically patients who have the monofocal lens will choose to have distance focus and use reading glasses for near vision. There are multifocal/accommodating IOLs available for patients who are appropriate candidates, to allow the patient a larger range of vision at far, near and intermediate (computer) distance and may allow great independence from glasses. There are still other IOLs which can correct astigmatism (a special type of glasses prescription) at the time of cataract surgery. After discussion of the patient’s needs and preferences, the surgeon can best advise their patient regarding which type of IOL may best suit them.

6/11/15

Anand Bhatt, MD - cataract preventionAnand B. Bhatt, MD
Assistant Professor of Glaucoma and Cataract Surgery, Gavin Herbert Eye Institute
UC Irvine School of Medicine