What is Botox? | Botox For More than Just Wrinkles

Botox was first used by an ophthalmologist to correct double vision and facial spasms.  But today, Botox is best known for its ability to temporarily cure wrinkles and “crow’s feet.”

Back in the late 70s an ophthalmologist from California, Dr Scott, was looking for a way to help patients suffering from involuntary facial spasms and people with double vision. He figured out that with a purified version of botulinium toxin,  he could temporarily weaken or paralyze a muscle.  His first success was in treating patients suffering from double vision caused by the extraocular muscles which move the eye.

This discovery was just the first success story for Botox and has lead to further adoption in most of the fields of medicine.  Today, Botox is approved for various spastic disorders, headaches, over production of saliva…and all kinds of wrinkles.

The Botox discovery changed the lives of millions of people and has become one of the top used drugs of all time.

What is Botox?

Botox is a purified protein obtained from a bacteria called Clostridium botulinum.  This bacteria is responsible for causing the disease botulism. curacao .  The bacteria produces a protein called botulinum toxin.  We currently know “botulinum toxin” as simply “Botox.”

After Dr Scott sold the rights of this drug to Allergan, the pharmaceutical giant developed the many cosmetic uses for Botox.

Botox is simply injected directly into the affected muscle, the toxin then paralyzes the muscle for up to 3 months.  Side effects are few.

Botox and Lid Spasms

The original application for Botox was for certain cases of double vision.  Now, there are dozens of uses for Botox and here are a few related to ophthalmology.

Involuntary movement of a muscle is a spasm. When this occurs around the eye it is called a blepharospasm. This can appear as constant blinking when both eyes are involved or “winking” if only one side is affected.  Severe spasm of multiple groups of facial muscles can occur and cause an abnormal posture or grimace.  Bright light, dry eye, and even anxiety can make the spasms worse.

Blepharospasm can cause decreased vision, watery or dry eyes,  headaches and can even lead to social issues and depression. Most of the time the condition occurs from an unknown cause and tumors are only rarely seen. Before Botox,  the treatment was often systemic medications or disfiguring surgeries.  After the release of Botox the treatment of this disease underwent a dramatic change. Now with a few injections around the eyes the spams can be relieved for 3 months or more in most cases.

Botox at Sarasota Retina Institute

Neuro-ophthalmologist and oculoplastics surgeons commonly prescribe Botox.  We have some patients that have been getting this for almost 20 years in our practice and are still delighted with the results. It is a life changer. Insurance does cover this procedure which is a big relief to patients.

In the next article I will talk about the use of Botox for double vision and the relief of migraines.

If you or some one you know has spasms of the eyelids/face, double vision, or suffer from chronic migraines, call our office at 941-921-5335 and schedule an appointment to see if Botox could help you.

Tumors AROUND the Eye | Ocular Tumors

Last article gave some basic information about  tumors and what it means to be a malignant tumor. I would like to start talking about some of the tumors we see around and in the eye.

Tumors of the Eyelid

The outer most structures of the ocular system are the eyelids. The skin around the eye can develop tumors (benign or malignant) and so can the deeper tissue, some which can be potentially deadly.

I strongly recommend that any new lesion (aka lump or bump) on the eyelids be evaluated by a doctor trained and comfortable evaluating eyelid lesions.  Most oculoplastic eye specialists should be very comfortable evaluating tumors of the eyelids or surrounding structures.

Basal Cell Carcinomas

Basal cell carcinomas are one of the most common type of skin cancers. The tumor arises from uncontrolled growth of the bottom layer of the skin. They are commonly occur on the lower eyelids as the lower lids receive more sun exposure than our upper lids.  These types of cancers are often seen in patients over 50.

The lesions are often raised red areas, with enlarged blood vessels around or in it, and an ulcerated center. If it is growing at the edge of the lid near the lashes there is often a loss of the lashes (called madarosis). These lesions are usually slow growing and rarely metastasize to other areas.

Basal cells are usually very superficial, but there can be extension under normal skin. The basal cell cancers are removed with surgery and often examined pathologically at the same time to ensure the entire lesion is removed. Depending on the size of the lesion removed various reconstructive techniques are used to repair the remaining healthy lid tissue.

Squamous Cell Carcinomas

Squamous cell cancers arise from uncontrolled growth of the skins upper layer of skin (epidermis). These are less common then basal cell carcinomas. They are also induced by chronic exposure to sunlight. The incidence of both squamous and basal cell cancers can be reduced by wearing sunscreen, hats, and sunglasses. These tumors appears as scaly red patches that can bleed if scratched. These lesions can grow and spread to deeper structures. The lesions needs to be completely resected (removed) and then the area reconstructed. Incomplete excision can lead to the lesion spreading down nerves and can lead to extensive disease and possible death.

Sebaceous Cell Carcinoma

Sebaceous cell carcinoma is a lethal eyelid tumor that arises from the glands around the eye. While they are rare these tumors can be misdiagnosed for benign conditions such as chalazions (styes). They can often start as a yellowish nodules and progress to a chronically red looking lesions. There is often eyelash loss in the affected areas. The cancer is usually not painful. These tumors can spread throughout the orbital area and even to other parts of the body (a malignant tumor). The treatment for this tumor is surgical excision, which can be very disfiguring and possible chemotherapy. Even with this treatment the prognosis is often poor for long term survival. Early examination and diagnosis is essential.

Tumors of the eyelids are not uncommon, especially in the south like Florida. If you have a concerning “lump or bump” on your eyelid or around your eye, make sure you see an oculoplastic surgeon like Drs. Abrams, Spoor or Levy.

In the next article we will talk about tumors that involve the inside of the eye.


Tumors of the Eye | Ocular Tumors

As a neuro-ophthalmologist/oculoplastic specialist,  I treat patients with various tumors around their eye.

Tumors of the eye can occur on the eyelids, the eyeball itself, the tissue around the eye (the orbital area) or even the optic nerve.

Any tissue can develop a tumor.  Different types of tumors in various tissues often have characteristic behaviors.  These tendencies help us decide the appropriate treatment.  These articles are to help you understand some of the tumors that are seen around the eye.

Tumor and Cancer NOT Synonyms

Most people use the term tumor and cancer interchangeably but these do not mean the same thing. A tumor or neoplasm is an abnormal growth of tissue.  This can be any tissue in the body. Some tumors are benign and some are malignant.  The difference is based on the way the tissue act.

Benign tumors are tumors which do not spread, or metastasize, to other parts of the body.  Though a benign tumor does not spread, it can still cause damage.  For instance, large benign tumors of the optic nerve can cause loss of vision by compressing the nerve.

Depending upon the size, rate of growth and potential to blind, these tumors may be watched (i.e. left alone) or removed surgically.

Malignant Tumors

Malignant tumors can spread to other parts of the body.  There are different ways for the tumors to spread.  Parts of the tumor can spread through blood, lymphatic system, or directly invade surrounding tissue.  Often, malignant tumors are difficult to treat because they spread by multiple ways; not just one.

Treatment for malignant tumors can include surgery, chemotherapy and/or radiation.

Tumors Affecting the Eye

There can be either malignant or benign tumors around the eye. The tumor can be formed from local tissue (called a primary tumor) or have spread from other areas (called a metastasis). Sometimes in office examination , radiology imaging, or surgical biopsy with pathologic examination is needed to help determine the origin, type of tumor and then treatment course.

In our next article we will discuss some of the specific tumors we see around the eye and ways to diagnosis and or treat them.

The doctors here at Sarasota Retina Institute have special training dealing with tumors around the eye. Drs. Abrams, Spoor and Levy are part of a small group of surgeons in the country who work both on tumors of the eyelids and orbits. Using state of the  art techniques and equipment they are able to offer our patients care the rivals large academic centers around the country.

New Opportunity for Dry Macular Degeneration Patients

Over the last year we have talked about an incredible device that can be used for patients with dry macular degeneration. The implantable miniature telescope (IMT) has been placed in numerous patients around the country giving them increased independence. In the past the patients had to have advanced dry macular degeneration, not had cataract surgery yet, and be over the age of 75. Well needless to say that was a very limited group of patients with macular degeneration.

The Government Changes

Just recently the rules for who can get a implantable miniature telescope has changed. The patient still has to have advanced dry macular degeneration, have not had cataract surgery, but now the age limit is 65 and older. Dr Levy is very excited with this change in the rules. This now allows him to offer the treatment to a much larger group of patients that previously had little options for improvement in their vision

What is the Implantable Miniature Telescope?

In patients with dry macular degeneration they lose their central vision. The center of the back of the eye is damaged, but the side or peripheral areas is usually left untouched. Regular glasses focus light on the center part of the eye, and  with macular degeneration the light information can not be used no mater how good the glasses. The implantable miniature telescope is placed inside the eye during cataract surgery. This specially designed lens then enlarges the image in front of the patient and projects it onto areas of the peripheral retina. This can have significant improvement in the patients overall vision.

Where Can Patients Get Evaluated For a Telescope Procedure?

If you or a loved one has advanced dry macular degeneration, has not had cataract surgery in at least one eye, and is over the age of 65 there are a limited number of centers in the country that can offer you some hope by putting in an implantable miniature telescope into the eye. We are lucky in the western coast of Florida to have Dr. Marc Levy performing this procedure. Dr. Levy has been involved with the telescope and its surgical procedure since the original FDA trials since 2002.  He is currently the only physician in this area who it qualified to preform this life altering procedure.

Please watch the below videos for more information on the telescope.

Sarasota Florida ABC7 News WWSB (may be slow to load) 11/5/14

Detroit Michigan Local4 News WDIV 11/6/14

South Bend Indiana / Notre Dame NBC16 WNDU 11/6/14

Flint Michigan ABC12 WJRT aired 11/5/14

Beaumont Texas CBS 6 Nov 7, 2014 KFDM

If you notice Dr Levy is presented in these videos from around the country. This is due to his long experience and expertise with the IMT.

If you or a loved one wants to learn more about what the implantable miniature telescope can do for people with dry macular degeneration, please call 941-921-5335 to make an appointment with Dr Levy.



Jody Abrams, MD, FACS
Sarasota Retina Institute
Sarasota, Florida 34239

Getting Your Bell Rung

What Is A Concussion

A concussion is a complex pathophysiological process which results in an injury to the brain. The process starts with direct or indirect trauma to the head.

In more general terms is it an injury to the nerves that make up our brain. Direct trauma or force to the head is not needed. This can be from rotational, acceleration or deceleration of the head.

How Common Are Concussions

Concussions are very common injuries in motor vehicle accidents, athletic injuries, and even falls. In the past few years concussion are becoming a hot medical topic as we learn more of their immediate and long term effects.

It is unknown how many concussions occur every year. Most concussion go unreported. Loss of consciousness occurs only about 10%. The medical community is working to raise awareness by educating the public to recognize concussions.

This will help people get tested and treated to help limit long term effects.

 What Are Indications Of A Concussion

Signs and Symptoms of a concussion include:

  • Memory loss
  • Confusion
  • Loss of coordination
  • Double vision
  • Blurred vision
  • New onset of problems reading
  • New Headaches
  • Dizzy feeling
  • Sadness
  • Difficulty with concentration

Diagnosing A Concussion

It is important to recognize a concussion to prevent repeat damage. If a second concussion occurs while healing from the first incident, this can lead to swelling of the brain. If this is not treated quickly death can occur.

There is no specific test to diagnose a concussion. Diagnosing a concussion can be challenging. A lot of times in medicine we rely on a specific test such as blood work or MRIs.  There is no blood test or imaging (like MRI or CT ) that will show when a concussion occurs.

There are neuro-psychological tests that can be used to help diagnose a concussion. These specialized tests compares pre-concussion brain speed with post-concussion brain speed.

The problem is with this is you need a baseline of how the brain was working prior to the concussion to see the change. This type of testing is fast becoming the standard for most contact sports. For example, “pre-concussion” baseline testing is obtained prior to the start of the season. Any suspected concussion compares the athletes ability to perform the same baseline exam. Results can indicate concussion.

This is great for activities like sports where test can be done prior to the season. In patients without baseline testing neuro-psychological testing can help often have to be more extensive.

 How Do The Eyes Help Diagnosis a Concussion

Neuro-ophthalmologists can perform additional tests like visual field testing, ocular motility testing, and even VEPs to aid in making a diagnosis.


So when a concussion is diagnosed treatments include rest, retraining of the brain, and limiting reoccurrence of injury. Each time the brain sustains an injury cells are lost. After loosing enough cells (which varies with each person) disease such as Alzheimer’s can develop earlier in life then normal.


If you or someone you know has suffered a concussion and are experiencing visual problems call our office at 941-921-5335 to come in for an evaluation.

Jody Abrams, MD, FACS
Sarasota Retina Institute
Sarasota, Florida 34239

Reducing Migraines | Treatment for Migraine Headache

Migraine headaches can be severely debilitating.  A migraine may have a variety of symptoms but includes an intense headache lasting several hours or days and often has associated light and sound sensitivity.

Patients are often nauseated and can have episodes of vomiting.  Most patients with migraine are unable to perform normal daily activities, much less completing a day of work.

Migraines must be diagnosed by a physician based upon symptoms and elimination of other neurologic conditions.  I am usually referred patients requiring treatment after other medications have failed.

Treatments for Migraines

The first step in treating migraines is to identify the cause. This can be certain foods or sounds that trigger the migraine.  In these circumstances, treatment is easy…avoid the foods or sounds which trigger the attack.

Usually no one specific cause can be identified and medications are needed.  The first line of medication are migraine abortive medications.  Abortive medications, such as Imitrex, are taken as soon as a migraine starts. They can often stop or lessen the effect of the migraine.

The medication needs to be used as soon as signs of a migraine start. They are great for people who have the occasional migraine, but should not be used more then about 3 times a week. Overuse of the medication can actually cause headache from a rebound effect.

Prevention of Migraine Headache

Over the last 20 years medications that treat blood pressure or seizures have been used to limit the number and frequency of migraines.  These preventative medications have been used with success to allow these patients a more normal life.

Unfortunately, there are often have unintended side effects that must be balanced with the benefits they provide. The drugs have also been used “off label.”  This means that the primary indication for the drug is NOT for migraine, but since the drugs are effective, they have become the standard of care and are used routinely for these purposes (don’t worry, this is confusing, but quite common in medicine!).

Botox FDA Approved for Migraine

Botox was approved in 2010 for the prevention of chronic migraines by the FDA. This makes Botox the only FDA approved drug for the prevention of chronic migraines.

The current thought is Botox actually has some pain relieving properties. This reduces the amount of stimulus that the brain gets and stops the migraine cycle. Patients will sometime report that they feel a migraine might start but does not progress into a headache.

The drug is administered in the office through a few injections sites in the front and back of the head. The side effects of Botox are usually minimal if any. The patient will often get improvement about 4-5 days after the injection.

Studies have shown patients need at least 3 rounds of injections to get the maximal effect. The injections are 12 weeks apart. As this is now FDA approved most insurance companies are covering this treatment and patients are getting relief.


If you or someone you know suffers from chronic migraines, call Sarasota Retina Institute at 941-921-5335 to schedule an appointment for possible treatment.





Jody Abrams, MD, FACS
Sarasota Retina Institute
Sarasota, Florida 34239

Concussion and Vision Changes Part 3

Concussion and your vision (part 3): double vision

       Last time I discussed what happens to you ability to see after a concussive head injury.  When your head hits a stationary object or is struck by a concussive blow the brain is jolted around the cranial cavity and is injured by smooth and sharp bones (fig 1).   The three nerves that innervate the muscles that move your eyes exit the brain stem and travel along the base of the skull, coming together behind the eye and enter the orbit thru a narrow canal to innervate their respective muscles that move the eye (fig 2).   These nerves are susceptible to injury anywhere along the route from the brain stem to the eye muscles.   Injury to any or all of these nerves results in a distinct pattern of double vision.   With this knowledge a neuro-ophthalmologist can determine which nerve is involved and how and when to treat the patient.


Thomas Spoor MD

Fig 1 (Click to enlarge)

Closed Head Injuries 01 d002

Fig 2 (Click to enlarge)





Double Vision: 6th Nerve Palsy

The patient in figure 3 has a sixth nerve palsy.  This nerve only moves one muscle, the lateral rectus that moves the eye to the side.   Due to its long passage from the brainstem to the lateral rectus muscle, damage to this nerve is the most common squeal of concussive injuries (fig 3a).  These patients complain of horizontal or side-by-side double vision and cannot move their eye to the side.  The double vision is very bothersome and there is no immediate treatment except to patch either eye.   This will resolve the double vision as long as the eye is covered.  Now begins the waiting game.  You really must wait 6 months to see the extent of spontaneous recovery.  If partial recovery occurs continue to wait until the amount of misalignment is stable.  Appropriate surgery is then very effective resolving the double vision.

Closed Head Injuries 01 d025

Fig 3a (Click to Enlarge)

Fig 3(Click to enlarge) Patient looking to her Right

Fig 3 (Click to enlarge) Patient looking to her Right

If there is no improvement, surgery is still helpful but less successful.  There is always residual double vision when the patient looks to the side but you can usually resolve the double vision straight ahead and in most other gazes.

I will talk about other cranial nerve injuries that can cause double vision from closed head injuries. If you our some one you know is suffering from any of these ocular problems please contact us for evaluation and treatment.

Tom Spoor, MD
Oculoplastics and Neuro-ophthalmology
Sarasota, Florida

Tom Spoor,MD
Oculoplastics and Neuro-ophthalmology
Warren, Michigan

Eyes Squeezed Shut


Do you ever have a problem where your eyes want  to squeeze shut uncontrollably?   Do people accuse you or winking at them? Do you feel your lid twitching?

If you answered  yes to any of these you could be having blepharospasm.

What Are Blepharospasm

The eyelids have a muscle that goes around in a circle in both the upper and lower lids, called the orbicularis. This muscle is responsible for closing the eye. In patients with blepharospasm the muscle squeezes involuntarily.  This muscle over powers the muscle that opens the eyelid, the levator muscle, and causes the eye to shut.

 Causes of Blepharospasm

The spasms are caused by over stimulation of the muscle or the nerve that controls the muscle.  Sometimes this can be a tumor, trauma, dry eyes, or even an abnormality of a blood vessel. These are actually the rarer causes of blepharospasm. Most often there is no specific reason for the spasms, and this is called benign essential blepharospasm (BEB). This is a really fancy way of saying we do not know the true cause, yet it’s not due to a disease.

Treatment For Blepharospasm

30 years ago had you walked into your doctors office with blepharospasm the main treatment would have been sedating oral medications or surgery to remove the muscle, which was often very disfiguring. In the late 70s early 80s an ophthalmologist, Dr. Alan Scott, figured out that injecting botulinum toxin (Botox) into the muscle would temporally relieve the spasms.

Botox Preferred Treatment for Blepharospasm

And such Botox was created.  It was not until almost 12 years later that the use of Botox for cosmetcs was discovered.  Today injecting a botulium toxin (Botox/Xeomin/Myobloc)  for blepharospasm is still the preferred treatment.

 Botox Covered by Insurance

About 10 sticks per eye with a tiny needle is often all that is needed to reduce or eliminate the problem.   Treatment may be repeated in 3 months if needed. This is a medical problem and is paid for by most insurance plans.

If you or someone you know is suffering with blepharospasm call on of our neuro-ophthalmologsit at 941-921-5335 to get help.




Jody Abrams, MD, FACS
Sarasota Retina Institute
Sarasota, Florida 34239

Diabetic Macular Edema

What is Diabetic Macular Edema

 Macular edema is defined as an abnormal macular thickening and excess fluid in the extracellular space of the retina. It is considered the leading cause of vision loss in the developed world in the working age population.

Current trends in the treatment of Diabetic Macular Edema

The Diabetic Retinopathy Clinical Research Network study in the USA, investigated ranibizumab (Lucentis) vs. Triamcinolone (an steroid) with laser treatment (Prompt versus deferred) and laser alone. It showed that the patients treated with ranibizumab had superior visual acuity results compared with the other groups.

Another randomized clinical study was the RIDE / RISE study (USA and Europe), comparing two different doses of ranibizumab versus a sham treatment for diabetic macular edema. Those with the ranibizumab gained on average 12 letters of visual acuity versus only four letters in the sham treatment group.

Also these studies demonstrated that the eyes that were treated with anti- VEGF agents as ranibizumab were more likely to have an improvement in their Diabetic Retinopathy Severity Scale and reduced the risk of Proliferative Diabetic Retinopathy (PDR) or the the end stage of diabetic retinopathy.

The eyes that received ranibizumab, less than 15% progressed to PDR at 3 years compared to 40% in the sham study eyes, significantly reduced the risk of severe vision loss.

In the United Kingdom, the BOLT study involved 80 eyes using bevacizumab or Avastin, an off-label treatment originally approved in the USA for colon rectal cancer and breast cancer. It showed that bevacizumab was superior to laser treatment.

Also the VIVID and Vista studies evaluated aflibercept or Eylea versus laser treatment. It showed that eyes that received Eylea gained on average 10 letters of visual acuity versus only one letter in the laser treatment group

What is the Newest Treatment for Diabetic Macular Edema?

In conclusion, the most recent data suggest that anti vascular endothelial growth factor agents previously discussed are becoming the first-line of treatment for macular edema and if the patient does not respond to these then we can add or combine them with laser treatment and steroids.

 Where To Get Treatment For Diabetic Macular Edema

All these agents are available at Sarasota Retina Institute and are performed routinely by Dr. Torres. If you have been diagnosed with diabetes, it is important to have at least a yearly exam of the retina to appropriately rule out, diagnosed and/ or treat diabetic retinopathy by a vitreo-retinal specialist.

Dr. Waldemar Torres, is a board certified and fellowship trained vitreo-retinal surgeon / sub- specialist that is available for the diagnosis and treatment of vitreo-retinal diseases such as diabetic retinopathy, age related macular degeneration, retinal detachment and acquired and congenital conditions. Call 941-921-5335  to schedule an appointment.


Waldemar Torres, MD 

Vitreo-retinal Surgeon

Sarasota Retina Institute

Sarasota, Florida



Jody Abrams, MD, FACS
Sarasota Retina Institute
Sarasota, Florida 34239

The Normal Eye

Over the last year we have talked a lot about problems with the eye. What we would like to do now is take a step back and talk about the normal eye. We hope that this will help add understanding to our previous articles. The picture was created by our own retina specialist, Dr. Chen.


This is the clear front portion of the eye.  It excludes the white portion of the eye which is the sclera (to be discussed later). Simplistically, it has 3 basic layers (more in reality).  The first is the epithelium, the second is the stroma, and the third is the endothelium. The epithelium covers the front surface of the cornea and is kept smooth by the tears produced elsewhere.  Without the wet film over the epithelium, the surface is roughened and the vision decreased, and if it is severely roughened and/or abraded, nerve endings are exposed which results in pain.  Common disorders of the cornea are dry eye syndrome, foreign bodies, ulcers, trichiasis, edema, etc. The stroma makes up the major portion of the cornea, creating its curvature and participating in the focusing of the image to the back of the eye.  An irregular loss of or scarring of the stroma will result in distortion or hazing of the image projected to the back of the eye and thus blurred vision. The endothelium is a single cell layer on the back side of the stroma.  It is responsible for keeping the stroma and epithelium dry.  Loss of the endothelium cells permits any fluid entering the epithelium or stroma to result in swelling and then, loss of vision.  Loss of the endothelium cells are most commonly caused by trauma, multiple eye surgeries or hereditary.

Anterior chamber:

This is the space behind the cornea and in front of the iris, it is filled with a liquid called aqueous, which is produced by the ciliary body (to be discussed later).  The fluid remains clear, but in cases of inflammation,  cells and flare are observed.


This is the colored part of the eye, which is seen through the cornea.  It acts like the shutter of a camera, adjusting the amount of light which enters the eye.  Closure of the pupil, or constriction of the pupil, occurs when in bright light and when focusing up close. Common disorders include trauma which damages the muscles around the pupil (the round opening in the center of the Iris) causing it to become irregular.  With inflammation the edge of the pupil may adhere to the surface of the lens preventing it from either opening up or closing down, depending where the adhesion occurs.  Severe trauma may also cause the iris to tear away from its peripheral location near the cornea.

Ciliary body:

This is the structure just behind and connected to the iris.  It has two functions.  The first is to produce aqueous and, the second is to adjust the lens, thus focusing the image on to the macula (to be discussed later). Aqueous is important to the eye because it keeps the pressure in the eye.  Without the aqueous the eye would collapse, just as a basketball would without air.  The continuous production of aqueous is necessary because there is a drainage system in the eye which allows for its outflow.  If there were not an outflow the pressure in the eye would elevate leading to glaucoma. Damage to the ciliary body would result in low pressure in the eye and effect vision.


These are fine fibers that originate from the ciliary body and connect to the periphery of the lens.  As the muscles in the ciliary body contract, the zonules pull on the lens resulting in its flattening thus decreasing its refractive power, and if the muscles relax, there is not tension of the lens through the zonules, and the lens thickens, thus increasing the refractive power of the lens.


This is the primary means by which an image is focused on the back of the eye, and more specifically on the macula.  As mention above its ability change its focusing power is due to the ciliary body through the zonules.  The lens is also the object of discussion when dealing with cataracts. Nuclear cataracts are the most common type.  They are due to aging the center of the lens initially becomes less pliable, resulting in a shift toward myopia (near sightedness) and presbyopia (inability to focus up near).  With further aging there is greater hardening of the central portion of the lens, which also becomes discolored, progressing from light yellow to dark yellow, then turning to brown, and in unusually advanced cataracts, black. Cortical cataracts involve the part of the lens peripheral to the nucleus of the lens.  It can develop clefts, vacuoles and/or opacities, causing disturbances in the uniformity of the lens and thus decreased vision.  Rarely the cortex can swell to such an extent that it pushes so tightly on the back of the iris that it prevents the natural flow of aqueous out of the eye resulting in a form of glaucoma. Posterior subcapsular cataract involves an opacification on the back surface of the lens.  It can vary in density, but even if small it can significantly affect vision when the pupil constricts which occurs in bright lighting and reading.   Mel Chen, MD Vitreo-Retinal Surgeon Sarasota Retinal Institute  Sarasota, Florida