Centrasight Intraocular Telescope Improves Vision for Macular Degeneration

The implantable telescope for macular degeneration continues to be successful.

For the last few years we have talked about the implantable miniature telescope. This incredible devices has been used to give patients with end stage macular degeneration improved vision. Marc Levy, M.D.  has been involved with the telescope since the early FDA trials and is currently the only surgeon in our area preforming the surgery.

Implantable Telescope Improves Vision

Recently a long term study of patients with the telescope was completed and published. This study followed 129 patients over 5 years after implantation of the telescope. The results showed that most patients got significant improvement of vision at about 2 years after the telescope was placed, and this improvement appeared to continue for at least 5 years.

The study was used to by the FDA to allow all patients 65 and older with end stage macular degeneration to be eligible for the telescope. It is now the only FDA approved surgical device to treat most advanced forms of macular degeneration. With macular degeneration affecting over 15 million people in this country the telescope gives some hope to patients that are in the advanced stage of this disease.

What is the Implantable Telescope?

The implantable telescope, by CentraSight, is a tiny telescope inserted in the eye.  In qualified patients with macular degeneration, the telescope has successfully improved vision and the quality of life for its recipients.

The “telescope” projects images onto the retina outside of the degenerated macula.  The images are larger, perhaps 2.2x or 2.7x, and projected to the healthier retina near the macula.  This enlargement enables the less sensitive, but healthy, retinal tissue to replace central vision.

Qualifications for Implantable Telescope

To be a potential candidate, your eye doctor must confirm;

1.  You have End-Stage Macular Degeneration from either Wet or Dry AMD

2.  You no longer will need treatments such as anit-VEGF injections

3.  You have not had cataract surgery in the eye with AMD.

4.  You meet the age, vision and corneal health requirements.

If you or someone you know is affected with macular degeneration please contact our office for an evaluation at 941-921-5335.

 

Therapy for End Stage Age-Related Macular Degeneration

End stage age-related macular degeneration may result in several presentations. Those with the extreme form may have had extensive hemorrhaging both under the retina and into the central cavity of the eye, or may have chronic leakage from abnormal blood vessel, which can not be closed off by any of the current treatments.  In those cases, there is very little that can be offered in the way of improving vision or aiding the patient in maximizing the use of their remaining vision.

There are, however, patients with age-related macular degeneration who have significant loss of central vision, but have been stabilized through treatment or, are dry and progressing very slowly.  These patients, in the past, have benefited from low vision devices. Such devices included very strong reading glasses, magnifying glasses, loupes, telescopes, and closed circuit television.  Many of these devices were cumbersome and/or impossible to carry around and were not effective under certain lighting conditions.

To this end, a device has recently been FDA approved which will overcome many of the shortcomings of previous low vision devices.  This new addition, to the assist those with stabilized poor central vision, is the Implantable Miniature Telescope (IMT). However, not all patients with stable low vision will qualify for the use of this device.

What is the IMT?

The IMT is a very small telescope which is implanted inside the eye, similar to having an intraocular lens implant for those who have had cataract surgery.  The difference is that the IMT is a much larger implant than the intraocular lens used in routine cataract surgery, nor is it as flexible, so it can not be implanted, folded, through a small incision.  This consequently would require the use of sutures to close the eye and a somewhat longer post-operative recovery period.

Does the Use of the IMT Require Any Special Adjustment?

Unlike normal cataract surgery where vision is restored to “normal”, there is a difference in image size and visual field.  Before the surgery, every patient is placed through a “simulation trial” to determine if they can adjust to the “new vision”.  If they pass this trial and they still desire to have the IMT, the surgery is performed similar to cataract surgery, and usually, under local anesthesia.  But even after the surgery there is a period of visual rehabilitation training in order to achieve the full benefits of the IMT.

Are There Special Criteria to be Fulfilled?

Before a patient can be considered for the IMT, there are currently certain conditions which must be met.  These include:

  1.   ARMD which is irreversible, end stage, and stable
  2.   No longer on any drug therapy for ARMD
  3.   Have not had prior cataract surgery
  4.   Have a clear cornea with normal endothelial count
  5.   75 years of age or older
  6.   Best corrected vision between 20/80 and 20/800
  7.   Prior vision correction: less than -6.0 and less than +4.0

Where is the Surgery Being Performed?

Currently there will only be a select few practices within the United States which have been approved to do IMT surgery.

These facilities are multi-disciplinary and have been setup in such a manner that they have ophthalmologists who have experience in determining the eligibility criteria and performing the surgery, optometrists who are trained in low vision evaluation, and visual occupational rehabilitation therapists who are experienced in assisting patients in adapting to the use of the IMT.

For further information, inquire at:  Sarasotaretinainstitute.com

 

 

 

What is Fluorescein Angiography?

Fluorescein angiography is a photographic means of imaging the retina. Prior to the introduction of the OCT (ocular coherence tomography), it was the primary method of imaging the eye for the diagnosis and documentation of its condition, evaluating response to therapy, and to discovering any changes in the eye which could not be perceived clinically. It continues to be an important means of studying the blood circulation within the eye.  It is still a valuable diagnostic tool for a retinal specialist.

How is a Fluorescein Angiography Performed?

Fluorescein angiography is an office procedure which takes approximately 15 to 30 minutes. A fluorescein dye is injected into a vein in the arm, and as the dye circulates throughout the body, multiple photographs are taken of the back of the eye as the dye passes through both the arteries and veins within the retina. The camera used to take the photos is equipped with special filters which allow it to project a certain wavelength of light into the eye which activates the fluorescein dye, which is then photographed as it passes through the eye. As the photographs are taken, the camera also records the time taken for the dye to first enter the artery in the eye and the time to completely fill the vein.

What is Actually Recorded on the Photographs?

Documented on the photographs is the circulation of the dye as it passes first through the arteries, then the capillaries, and finally the veins. Delays in the normal circulation time indicate either arterial or venous occlusion. Fluorescein staining of the blood vessels occurs with inflammation and/or damage to the vessel wall, and if the damage is severe or the vessels are abnormal, dye will stain and/or leak out of the blood vessels and accumulate in the retina.

Also documented by these photos is the circulation of the vascular layer under the retina, any defects in the pigmented layer of the retina, and any abnormality which disturbs the normal fluorescein pattern of the retina.

Indications for Fluorescein Angiography

As discussed above, fluorescein angiography is used to document and diagnose eye disease, as well as monitor response to therapy. Ocular coherent tomography (OCT) is currently, being used more often to perform these functions; however, there are still a number of conditions and circumstances which still require the use of fluorescein angiography. These conditions include:

  • Retinal arterial occlusive disease
  • Retinal venous occlusive disease
  • Vascular anomalies and other diseases
  • Vasculitis and autoimmune conditions of the eye
  • Diabetes
  • Macular degeneration
  • Temporal Arteritis
  • Hereditary conditions involving the retina
  • Intraocular tumors

Are There Complications to Fluorescein Angiography?

The procedure is generally uncomplicated; however, on occasion there may be side effects. When starting the injection of the fluorescein dye, there may be difficulty entering a vein to inject the dye, in which case, multiple attempts will be made before a successful and clean entry is accomplished. If a good entry is not made, there may be bleeding around the injection site, or the dye may be injected outside the vein, which can cause significant discomfort depending upon the amount of dye that is misdirected.

As the dye circulates throughout the body, the most common side effect is a mild sensation of nausea, which quickly passes after a few deep breaths. Some people may develop hives and/or some tightness in breathing which are treated with Benadryl. If these side effects are known to occur, the Benadryl is given in advance.

On very rare occasions, there may be a much more severe reaction to the dye, an anaphylactic reaction, which can be life threatening.  All practices should have an emergency tray to handle this situation as well as immediate access to a 911 facility.

There are two additional, but benign, side effects of which the patient should be aware. First, there is a discoloration of the skin as the dye passes through the body. It will take on a yellow/orange appearance which lasts a few hours. Secondly, as the dye is eliminated from the body through the kidneys, the urine will appear orange.

What is an OCT?

Optical coherence tomography (OCT) is the most recent imaging innovation in ophthalmology used to study the structure of the eye.  Even more recent applications of this type of scan have been to study the anterior portion of the eye, but the primary usage has been for the evaluation of the retina, and more specifically the back of the eye.  This portion of the eye is called the posterior pole and includes the macula and the optic nerve.

There is a great similarity between ultra-sonography and optical coherence tomography, in that they both image by reflecting an impulse of energy onto the subject matter being studied and analyzing the energy reflected back.  The difference is that sonography uses sound waves, which can penetrate opaque matter, and OCT uses light waves, which only penetrate translucent matter.  Because light waves have a much shorter wave length than sound waves, there is much greater/better resolution in image presentation.

When to Use Optical Coherence Tomography

OCT is currently most often used to examine the macula in ARMD (age-related macular degeneration).  In this condition abnormalities in the retinal tissue can be identified and measured. These abnormalities include breaks in the outer retina tissues, accumulation of metabolic by-products, fluid under or in the retina, scar tissue under the retina or on the surface of the retina, and traction on the macula and/or surrounding retina.  Because of its high resolution the individuals layers of the retina can be identified, aiding in the diagnosis of the macular and retinal condition.

Other retinal diseases where an OCT is useful include;  macular holes and cases of macular pucker.

When used to evaluate the optic nerve, the OCT quantitates the amount of optic nerve damage, nerve swelling, and the degree of nerve fiber loss and location.  It can also reveal vitreous traction on the optic nerve.

An OCT is Non-Invasive and Does Not Hurt

The examination using the optical coherence tomographer is entirely benign, without any risk factors.  The patient is positioned in front of the OCT instrument and the head is placed in a frame for stabilization.  The instrument is then placed in front of the study eye, which is not touched,  and the patient is asked to look at a light target.  The Instrument, using a low intensity laser beam, scans the eye within seconds, and data is then printed out, including a cross-sectional view of the retina, a topographic view and the retinal thickness.

How often is an OCT Needed?

Besides aiding in the diagnosis of retinal and macular disease, the optical coherence tomographer is invaluable in evaluating the progression of a disease, as well as, showing if the condition is responding to treatment.  In some conditions, it may be used at each visit as continuation of treatment is based on the results of the study.  This is particularly true in the case of treating Age-related macular degeneration when an endpoint is determined when there is no longer any evidence of new vessel and all fluid has been reabsorbed.  The OCT has significantly decreased the need for fluorescein angiography, where an IV injection of fluorescein is required, followed by numerous photographs.  This procedure takes much more time and is more invasive.  It also has an additional risk, in that the patient may have an adverse effect to the fluorescein.

The use of the OCT has become a much more utilized imaging device in ophthalmology, but there continues to be a need for fluorescein angiography in certain cases where the cause of the macular damage is not revealed by the OCT. whois register . adobe creative cloud

What is a Retinal Specialist?

Retina specialists are specialized eye doctors who treat only diseases of the retina.  Ophthalmology is a specialty of medicine/surgery dealing with the diseases of the eye and the surrounding tissues, including the eye lids, eye muscles, eye orbit/socket, optic nerve and the optic tracks as they run from the back of the eye to their final destination in the occipital lobe, in the back of the brain.  Because of the many different aspects necessary for the proper function of the eye, ophthalmology has been divided into a number of subspecialties.  One of these is the specialty of retina.

 

The Retinal Specialist

The retinal specialist focuses his work on the retina, which is the sensory portion of the eye, the vasculature which supports the retina, and out of necessity, the vitreous which is the jelly material that fills the central cavity of the eye.  The retinal specialist is most often called upon when vision can no longer be improved after appropriate glasses have been prescribed and/or cataract surgery to determine the cause of the persistent decreased vision, or if there is any abnormality noted in the back of the eye on routine eye examination.

 

When Would a Retinal Specialist be Consulted?

Any condition in which there is decreased vision, which can not be explained by a condition involving the eye lids, cornea, and/or lens, could involve a consultation with a retinal specialist.    Conditions resulting in the clouding of   the vitreous can include vitreous degeneration, bleeding, inflammation/infection, and cancer.  If the center of the back of the eye (the macular) is involved, the most common major problem is macular degeneration. Other macular problems include  hereditary conditions, or the result of a number inflammatory conditions or infections, such as Histoplasmosis, Toxoplasmosis, AIDS, etc.  These conditions may also affect the peripheral retina.  Other conditions which can affect the macula include vitreo-macular traction syndrome, pseudophakic macular edema, macular pucker and macular hole.

Peripheral retinal conditions which would involve a retinal specialist include retinal tears and/or retinal detachments, diabetic retinopathy, hypertensive retinopathy, and tumors (both primary and metastatic), to mention just a few.

Vascular lesions include both arterial and venous occlusive disease, which may be either central or branch, and vascular anomalies.

Ocular trauma often falls into the realm of the retina specialist because there is usually bleeding into the eye with retinal damage.  This type of retinal damage may include giant retinal tears, retinal dialysis, macular swelling, and retinal hemorrhage.  Also when eye trauma occurs there may be a rupture of the globe and/or a foreign body within the eye.

How Do I Find a Retinal Specialist?

Retinal specialists can be located though the Yellow Pages, but it would be best to ask your current eye doctor for a referral.  In that way, you would be referred to a retinal specialist who has a good relationship with your doctor, and together they can best coordinate your care and follow-up.

Macular Degeneration: Who’s at Risk?

Risk factors for developing macular degeneration include both environmental and hereditary components.  The actual cause of this disease is not known, but is multi-factorial.

Age-related macular degeneration (aka ARMD) is the most common cause of blindness in the United States of adults, particularly those approaching the age of retirement.   Until relatively recently, the actual cause was not entirely known, and it still is not fully understood.

Hereditary/genetic factors which are uncontrollable

  • Age is the number one risk factor to consider when discussing ARMD.  It is the most common cause of blindness in those over the age of 60, and affects one third of adults over the age of 70.
  • Gender is a factor in that females are more likely to be affected, but this is most likely due to their longer life expectancy.
  • Those with a family history of macular degeneration are at greater risk, especially if the relative is in the immediately family.
  • Caucasians are more at risk than any other races, most likely due to genetic background and pigmentation.
  • Light colored eyes have an increased risk of developing macular degeneration because the lesser amount of pigment in the eye exposes it to greater damage from UV radiation.
  • The presence of the disease in one eye increases the likelihood of getting the similar condition in the fellow eye.

Risks factors which are controllable:

  • Smoking increases the chances of developing macular degeneration by a factor of 2 to 5 times.  It is most likely associated with a decrease in oxygen made available to retinal tissue which has a high oxygen demand.
  • Prolonged exposure of ultra-violet and blue light damages retinal tissue directly and leads the production of metabolic byproducts which are detrimental to eye function and lead to macular degeneration.
  • Diets high in fat and cholesterol, and low in antioxidants and nutrients have a higher risk in developing macular degeneration.  Fats and cholesterol ultimately affect blood vessels and flow, and nutrients and antioxidants are important for retinal tissue function and the removal of free radicals detrimental to cell metabolism.
  • Obesity is a risk factor in that an individual with a body mass index (BMI) greater than 30 is 2.5 times more likely to have macular degeneration.
  • Individuals with high blood pressure have an increased risk for macular degeneration due of its effect on the blood vessels, in that there is narrowing and therefore, less circulation to the retina.
  • Exercise improves cardiovascular health, therefore improves eye circulation, and is felt to decrease the risk for macular degeneration.

What Should I Do If I am at High Risk for Macular Degeneration?

If you have determined that you are at an increased risk for age-related macular degeneration, it would be important to first get a complete eye exam to include a thorough retinal evaluation.  This would determine if you are truly at high risk and should take appropriate steps in changing your life style and be placed on nutritional supplements with high antioxidant content.  You may also be advised as to how to monitor yourself in order to detect the onset of the more sight threatening form of macular degeneration, which is more successfully treated in its early stage.

To get a thorough eye exam, you should contact you local ophthalmologist/retinal specialist.