Is general anaesthesia required for retinal surgery?

Most people do not require general anaesthesia.  The eye can be very well frozen with an injection behind the eye.  In addition...the anaesthesia team gives patients intravenous sedation...so patients typically drift in and out of being awake.  If however a patient insists that they do not want to be aware of anything during the surgery...general anaesthesia can be used.

Are there any new drugs on the horizon for wet macular degeneration?

The short answer is NO.

The results with Lucentis have been so great...that many other manufacturers have abandoned development of drugs that they had been exploring...due to the huge costs involved. Any new drug will have to be shown to be better than Lucentis.

Currently...a drug called VEGF-Trap is in Phase 3 FDA trials...results are expected perhaps in 2011. VEGF-Trap will have to be shown to have better visual acuity improvement and/or less frequent dosing to have potential.

Very sophisticated new laser systems are also being explored (Opttx Medical)...perhaps to be used together with Lucentis...to decrease the number of injections required.

How many Lucentis injections will I need?

It is impossible to predict the number of injections a person will need for "wet" macular degeneration. It is important to recognize that Lucentis is not a "cure" but rather a maintenance therapy for macular degeneration. The body stimulates the growth of abnormal blood vessels in wet ARMD...for reasons that are not entirely understood. The body produces a chemical called VEGF...which stimulates the growth and leakage of these abnormal blood vessels. Lucentis...specifcally blocks VEGF...however Lucentis stays inside the eye only for about four weeks...and is then absorbed by the body...therefore...almost always...when the Lucentis gets absorbed...the blood vessels start to grow and to leak again...and more Lucentis is then required.

Most retinal specialists treat patients in a schedule similar to the following...an initial course of three Lucentis injections every four weeks...then careful monthly follow-up...with repeat injection at the earliest sign of recurrence or persistence of blood vessel growth and leakage.

What are the risks of an injection into the eye?

Retinal specialists inject an ever increasing number of medicines into patient's eyes (Amphoterecin, Kenalog, Macugen, Avastin, Lucentis, etc). These various medications have been extremely helpful in the management of many diseases such as macular degeneration, diabetes, infections and retinal vein occlusions. Techniques and anaesthetic agents have improved dramatically over the years...making the procedure much less uncomfortable than most patients fear.

There however still do exist some risks...from the injection itself. The main risks are that of infection ("endophthalmitis"), bleeding into the vitreous cavity, retinal tears, retinal detachment, cataract or corneal abrasion. The vast majority of patients however experience only minimal discomfort at the time of the procedure...and mild swelling and redness for a day or two post-injection.

What is VEGF-trap

VEGF-trap is a drug currently being investigated for the treatment of "wet" macular degeneration. As with Lucentis...it needs to be injected into the vitreous cavity...at a frequency yet to be determined...but in the four to six week range...also much like Lucentis. Much future study is still required to determine the efficacy and safety of this drug. Approval...if it is to occur at all...will not be for several years.

Who is Donald K. Johnson?

Donald K. Johnson is a Canadian philanthropist who was born and raised in Lundar, Manitoba. He currently resides in Toronto, Ontario.

Johnson received a BScEE from the University of Manitoba in 1957 and an MBA from the Ivey Business School in 1963. His initial career was in electrical engineering with Canadian General Electric in Toronto and Federal Electric Corporation on the DEW line in the Canadian Arctic.

Johnson began his career in the investment industry in 1963 when he joined Burns Bros. & Denton Ltd. Since then he has held a series of management positions in Institutional Equity, Sales, Trading, Research, International, Retail and Investment Management. He was President of Burns Fry (1984-1989), and Vice-Chairman, Investment Banking, for BMO Nesbitt Burns and predecessor companies (1989-2004). Mr. Johnson continues as a Senior Advisor at BMO Nesbitt Burns.

Johnson's activity in the non-for-profit sector is extensive. He serves on the Advisory Board of the Richard Ivey School of Business at the [[University of Western Ontario, and is a member of the Board of Trustees of the Toronto General and Western Hospital Foundation and Chairman of its Vision Campaign, a $15 million campaign for the Donald K. Johnson Eye Centre at The Toronto Western Hospitall. He is Chairman Emeritus and director of the Council for Business and the Arts in Canada, a trustee of the Toronto Foundation for Student Success, a director of the Canadian Club of Toronto, and a member of the 2005 Major Individual Gifts Campaign Cabinet of the United Way of Greater Toronto. He is a past board member of the National Ballet of Canada, the Bishop Strachan School Foundation, and was Chairman of the Investment Dealers Association and a Governor of the Toronto Stock Exchange. In 1996-97 Johnson chaired a successful $13 million capital campaign for the National Ballet to build a new home for the Company in Toronto. Johnson has played the lead role on behalf of the charitable sector in Canada in lobbying the federal government to remove tax barriers for gifts of publicly listed securities to registered charities. His efforts over many years met with success first in 1997 when the Canadian government cut the capitals gains tax for such gifts in half, and then further in 2007 when the tax was eliminated entirely.

Johnson is a recipient of the Outstanding Volunteer Award, Association of Fundraising Professionals (1997), Friends of the Association of Gift Planners (1997), Richard Ivey School of Business Distinguished Service (1998) and the Arbor Award for Outstanding Volunteer Service to the University of Toronto (1999).

Johnson was appointed a Member of the Order of Canada in 2005.

What is Densiron?

Densiron is a "heavy Silicone Oil" (composed of a mixture of polydimethylsiloxane and perfluorohexyloctane). It is a clear and colourless oil which is used to repair complicated retinal detachments in the lower portions of the eye. This "heavy" liquid is heavier than water...and thus sinks down...and keeps pressure on the lower portions of the retina...allowing time for laser burns to firmly adhere the retina.

It is used only temporarily...typically being removed (in a second operation) within three months. Densiron allows the repair of some complicated retinal detachments which otherwise could not be repaired.

Which is better...Avastin or Lucentis?

Both drugs are anti-VEGF drugs (vascular endothelial growth factor)...which means they block a factor produced by the body called VEGF. VEGF stimulates the growth and leakage of blood vessels...so these drugs block the growth and leakage from these blood vessels. Such abnormal blood vessel growth and leakage can occur in a variety of retinal conditions...such as "wet" macular degeneration, diabetes, vein occlusions and many other conditions.
Lucentis has been specifically engineered for use in the eye...and as such, has been extensively tested both for efficacy and for safety. Avastin, which is a much larger molecule...is actually a drug for metastatic colon cancer...it has however been discovered...in "off label" use...to also be effective for a number of these condtions.
A study...initiated by the National Eye Institute, in Bethesda, Maryland (the CATT trial) is currently underway...comparing the two drugs. We anticipate some early data from this study perhaps in 2010 or 2011.

Where is the Donald K. Johnson Eye Center?

The Donald K. Johnson Eye Center is located within the Toronto Western Hospital, The University Health Network, The University of Toronto. The address is 399 Bathurst Street, Toronto, Ontario, Canada. M5T 2S8. The Eye Center is located on the 4th, 6th and 7th Floors. Information can be obtained from the following two websites: www.tgwhf-uhn.ca/campaigns/dkjec/index.asp AND www.uhnophthlamology.com

What type of anaesthesia is required for retinal surgery?

Most adult patients are awake...but drowsy during retinal surgery. The anaesthetist will give sedatives intravenously...and the surgeon will freeze the eye with local anaesthetic. During the surgery...which typically takes between one and two hours...the patient will be drowsy but awake...and be aware of his or her surroundings. We want the patient to remain somewhat alert...because if the patient is too deep...they'll forget where they are and try to move (or climb off the operating room table!).
If a patient is claustrophobic...or just unable to contemplate being at all aware of the surgery...then general anaesthesia is used.

What's new in genetic therapy for retinal disease (CTV News)?

what is "pneumatic retinopexy"?

Pneumatic Retinopexy is a procedure that can be used to repair some retinal detachments.

The procedure involves the injection of a gas bubble into the eye...using a gas which expands...the patient must then position themselves in a very specific way...such that the gas bubble pushes on and flattens the retina...the next day...the retinal tear or tears are sealed with either laser or cryopexy(freezing).

Approximately 50% of retinal detachments are potentially treatable in this fashion. The retinal surgeon's decision as to whether this technique is appropriate is based on the anatomy of the detachment and the number and location of the tear(s) and on the ability of the patient to assume the required position.

does Lasik reduce the risk of retinal detachment?

NO.

People who are near-sighted are at an increased risk of retinal detachment. It is true that Lasik (or "laser vision correction") can allow a person to no longer need glasses for distance...however...the risk of retinal detachment is not reduced.

The reason for the above is because people who are near-sighted have "longer" eyes than people who are not near-sighted. As a result...the retina in near-sighted people is more stretched and thinned...and is more likely to develop tears...which can lead to retinal detachment.

Lasik essentially carves the eyeglass prescription onto the surface of the cornea (thus eliminating the need for glasses) but it does not change the shape of the eye...and thus does not reduce the chances of developing retinal tears and retinal detachment.

how common is retinal detachment?

Retinal detachment is uncommon. The incidence is approximately 1/10,000 per year.

Certain situations however increase the risk...most importantly...cataract surgery increases the incidence to approximately 1/100! The risk of retinal detachment is also higher in people who are very near sighted, with a family history of retinal detachment and after injuries to the eye.

what is silcone oil?

Silicone Oil is a clear, colourless oil...used in the repair of complicated, recurrent retinal detachments...a small percentage of patients with retinal detachments develop recurrent scar tissue as part of the healing process...this scar tissue, if severe...can cause a recurrent retinal detachment ("proliferative vitreoretinopathy")...it is in these severe situations...that Silicone Oil is used....to help keep the retina in correct position.

how is a retinal tear treated?

The key to treating a retinal tear is to treat quickly...before a retinal detachment occurs.

Retinal tears develop as a result of pulling by the vitreous on the retina. If a tear is detected before fluid collects under the retina (a "retinal detachment") then thermal laser is used to surround the tear. Each laser burn...over a period of about 2 weeks...forms a small scar...this collection of scars "spot welds" the retina and seals the tear...preventing the progression to a retinal detachment.

what are "flashes and floaters"?

"Flashes" refer to when a person senses that there is present bright sparks of light present...yet there really are not. These occur because the vitreous pulls on the retina...and this pulling is sensed as a flash of light. When someone experiences flashes...they need to be examined by a retinal specialist...to ensure that the pulling by the vitreous did not cause a tear of the retina.

"Floaters" refer to when a patient sees floating images in their field of vision...much like the floating snowflakes in children's "snowglobes"...they are due to opacities within the vitreous cavity...they do not require further investigation or treatment...however rarely...if they are very central and persistent and bothersome...they can be removed with vitrectomy surgery.

what is a vitreous hemorrhage?

A vitreous hemmorhage refers to blood in the vitreous cavity of the eye. Blood can develop gradually or slowly...depending on the origin. Patients typically experience a severe loss of vision...the degree of loss dependent on the amount and location of the blood.

The most common causes of vitreous hemorrhage are...proliferative diabetic retinopathy, vitreous traction, branch retinal vein occlusion and trauma.

Vitreous hemorrhage oftentimes absorbs on its own. If the blood doesn't absorb....or if a retinal detachment develops behind the blood...vitrectomy surgery is required.

how can a person avoid developing diabetic retinopathy?

There is no way to guarantee avoidance of diabetic retinopathy...however maintaining careful, optimal control of blood sugar and blood pressure help reduce the risks. Regular eye examinations with dilatation of the pupils are also essential. Timely treatment with laser can usually prevent serious problems before they happen.

does everyone with diabetes develop diabetic retinopathy?

Almost all people with diabetes eventually develop some diabetic changes in their retinae...however most people have only very mild "background" changes. A small percentage get the more severe "proliferative" type of diabetic retinopathy.

Who should wear a visor when playing hockey?

EVERYONE should wear a visor when playing hockey.

Everyone...including children as well as adults....and professional hockey players.  In addition to ice hockey...eye protection is just as essential when playing informal pick-up games, including road hockey and floor hockey.

In Canada...we have been keeping careful statistics on eye injuries for over thirty years.  When eye protection became mandatory in children's hockey...a dramatic and sudden decline in eye injuries was noted.

In fact...there has NEVER been reported an eye injury in a player wearing a full-face mask.

Second best...but a distant second...are the half-visors.  These do not protect from a stick coming from down below.  The other problem with half-visors is that players tend to wear them incorrectly...pushed up toward the forehead...with a loose chinstrap.

how does a tear form in the retina?

The cavity of the eye is filled with vitreous gel.  The vitreous slowly becomes liquified in all people.  As a result...the gel portion of the vitreous becomes mobile...and starts to collapse and move towards the front of the eye.  In some people...the gel is very strongly attached to the retina in the back of the eye.  As the gel collapses and  moves forward...sometimes strong pulling occurs on the retina...this can sometimes lead to a tearing of the retina.  Fluid from the cavity of the eye can then collect underneath the retina...creating a retinal detachment.

what is an epiretinal membrane?

A

An epiretinal membrane (or as it sometimes also called..."macular pucker") refers to the growth of a cellophane-like growth of scar tissue onto the central macula.  This growth of scar tissue causes elevation and distortion of the retina...and a reduction in vision.  Such membranes are sometimes mild...but with time...usually progress.

If the vision is suffificiently reduced...the only treatment is to surgically peel the membrane off...with a vitrectomy operation.  Surgical results are excellent.

what is diabetic macular edema?

Edema means "swelling". In diabetes...blood vessels can oftentimes leak...causing fluid and fatty deposits to accumulate in the macula...much like a "wet sponge".  This thickened area of central retina does not function normally...patients experience reduced central detailed vision.

Numerous treatment alternatives exist for diabetic macular edema...including improvement in blood sugar and blood pressure control, laser treatment, drug injections (Avastin, Kenalog, Lucentis) and vitrectomy surgery.

what is central serous retinopathy?

Central serous retinopathy (or CSR") is a condition where a clear blister of fluid develops underneath the central retina. Patients complain of a loss of central and colour vision...and might notice that their prescription becomes less nearsighted.
Typically...CSR develops in young (20's) males...who are stressed or have "Type A" personalities. Most episodes resolves slowly on their own (average time about 4 months)...but if prolonged...laser treatment might be necessary.

can a macular hole be treated?

Yes..very successfully.

Treatment involves a vitrectomy...to remove all vitreous and to remove all traction on the edges of the hole...allowing the edges of the hole to come back together again. At the conclusion of the operation...the eye is filled with a gas bubble...and the patient is asked to lay on their face for a week. The bubble of gas can thus push on the hole...and help for the hole to heal and the edges to come together. Surgical success is approximately 95%

what is a macular hole and how does it develop?

A macular hole is a full-thickness hole in the center of the macula. Most commonly...they occur spontaneously...in women in their 60's and 70's. Macular holes are approximately ten times more common in women than in men...for reasons that are not known.

Patients notice a blind spot in the center of their vision...and a loss of detailed and colour vision.

Macular holes can often occur after injuries to the eye.

how does laser work in proliferative diabetic retinopathy?

Abnormal blood vessels develop in diabetes because the retina senses that it isn't getting enough blood. This is because diabetes damages the abnormal blood vessels of the retina. As a result...the retina releases a chemical which causes these abnormal blood vessels to grow (the chemical is called VEGF)

Laser works by destroying the less important retina...away from the center...as a result...the eye feels that there is less retina not getting enough blood...and therfore the retina releases less VEGF! Since there is less VEGF being produced...there is less stimulus for the abnormal blood vessels to grow.

what is proliferative diabetic retinopathy?

In diabetes...abnormal blood vessels sometimes grow on the retina...these blood vessels do not nourish the eye, like normal blood vessels do...they are fragile...and can tear...as a result...they can then bleed onto the retina or into the vitreous cavity of the eye. The vision can be severely reduced. Treatment involves a variety of approaches...including laser, drug injections (such as Avastin) and vitrectomy surgery. Better control of blood sugar and blood pressure reduce the risk of such complications. Regular follow-up is also essential...if such blood vessels can be found before they bleed....laser treatment can usually cause the blood vessels to dry up and greatly reduce the risk of bleeding and blindness.

what is endophthalmitis?

Endophthalmitis is a rare...but potentially vision threatening infection of the inside of the eye.

Typically endophthalmitis develops after surgery...most commonly cataract surgery. Patients notice pain, redness and swelling...accompanied by loss of vision...usually 2-5 days after surgery.

This condition is an emergency...and requires immediate referral to a retinal surgeon. Treatment involves the injection of antibiotics into the eye...and sometimes, vitrectomy surgery.

The outcome depends on specific type and amount of the bacteria which entered the eye...and the speed of treatment.

what is a vitrectomy?

A vitrectomy is an operation when the surgeon removes (under the microscope) the vitreous jelly from the cavity of the eye...and replaces it either with gas or saline.

Vitrectomy surgery is used for various conditions....most commonly...bleeding or scarring from diabetes, certain retinal detachements...or severe injuries to the eye.

Patients are typically awake...but sedated during such surgery...the eye is frozen with local anaesthesia.

what is a "scleral buckle"?

A scleral buckle is a type of operation...sometimes used to treat a retinal detachment.

A piece of silicone plastic is used to encircle the eye...and to push (or "buckle") the wall of the eye (or "sclera") inward...the fluid which collected underneath the retina (causing the retinal detachment) is drained...and the tear is sealed...either with freezing treatment ("cryotherapy") or with laser.

The success rate of such surgery is typically over 95%

what is retinal detachment?

The eye is like a camera...and the retina is like the film of the camera. Normally...the retina lines the inside of the eyeball...and is flat against the back wall of the eye.

A retinal detachment occurs...when a tear forms in the retina...which then allows fluid from the cavity of the eye (the vitreous) to pass through the tear...and under the retina. This causes the retina to lift up and peel off the back of the eye (like wallpaper peeling off the wall). Patients experience a sudden loss of vision...with a dark shadow in the vision...in the area corresponding to the portion of the retina which is detached.

Treatment is a surgical emergency.

what is a branch retinal vein occlusion?

A brach retinal vein occlusion (or "BRVO") is a blockage of one of the smaller veins which drain blood from the retina. The involved area of the retina is swollen...and blood leaks out in the area.

Patients experience a dark shadow in their vision...corresponding to the area of blockage.

A full work-up by the general physician is necessary...to rule out conditions such as diabetes, high blood pressure...and blood abnormals that would cause excessive clotting.

Patients are usually asked to start low-dose Aspirin daily...to reduce the chances of additional clots.

Treatment includes observation, laser, drug injections (Kenalog or Avastin) and sometimes, surgery.

what is a central retinal artery occlusion?

A central retinal artery occlusion (or "CRAO") refers to a sudden blockage of the main artery which supplies blood to the eye. Patients typically complain of a "sudden painless loss of vision". The retina has a very white appearance to it.

If caught quickly...various treatment options exist...to try to restore bloodflow to the retina.

If more than 24 hours have passed....treatment is typically not helpful.

what is a central retinal vein occlusion?

A central retinal vein occlusion (or "CRVO") refers to when the main vein...which drains blood from the eye...gets blocked...usually by a blood clot. Blood therefore cannot leave the eye normally...and leaks out throughout the retina. The retina also gets very swollen.

Patients typically experience quite a gradual but severe loss of vision (the degree of vision loss depends on how severely the blood supply gets reduced).

Patients need to see there general physician...and need to undergo many tests...to look for potential blood abnormalities, high blood pressure, diabetes...and other conditions. Patients are often started on Aspirin...to reduce the chances of a recurrent such blockage.

Treatment is often quite successful...and includes observation (sometimes spontaneous improvement occurs), laser therapy, various drug injections (Kenalog or Avastin) or vitrectomy surgery.

what are the visual requirement for driving a car in Ontario?

In the Province of Ontario...a person must have 20/50 visual acuity with both eyes open. This means that what a normal eye can see at 20 feet...must at least be seen at 50 feet. There are additional stipulations with regards to the extent of the visual field.

what does "legally blind" mean?

Legally blind vision means "worse than or equal to 20/200". This means that what a normal eye can see at 200 feet...a legally blind eye can see at 20 feet (10x closer).

what is "VEGF"?

"VEGF" refers to "vascular endothelial growth factor"...a protein released by the body...which stimulates the growth of blood vessels.

In the case of macular degeneration or diabetic retinopathy...the excess release of VEGF is harmful...causing the growth of abnormal blood vessels...such is in "wet macular degeneration" or "proliferative diabetic retinopathy".

Drugs such as Lucentis or Avastin reduce the growth of abnormal blood vessels by BLOCKING VEGF.

what is a "disciform scar"?

A disciform scar is a central scar, beneath the macula. It is the result of previously active wet macular degeneration...abnormal blood vessels in the area have bled...and now dried up...and left as a footprint...a scar.

There is no effective treatment. Patients have a central blindspot, loss of detailed vision and poor colour vision. Peripheral vision is retained.

Years ago...attempts were made to remove these scars surgically. Technically...the scars can be removed...however the retinal tissue above...and the pigment below...is typically damaged...and patients do not experience improvement in vision.

is Visudyne still used in the treatment of macular degeneration?

Visudyne was the treatment of choice for wet macular degeneration until about 2005.

It is a light-sensitive drug...which was injected into the patient's bloodstream...and then, a few minutes later...when the drug became concentrated in the abnormal vessels of the eye...the eye was exposed to a special laser...which was absorbed by the drug. The idea was to destroy the abnormal blood vessels (which had a high concentration of the drug) but not damage other nearby tissues.

Visudyne...at the time was quite effective at stabilizing vision...but only very rarely caused visual improvement. The results with Lucentis has been found to be so superior to Visudyne...and as a result...Lucentis has become the first choice of treatment with most retinal specialists.

what is Avastin?

Avastin (or Bevacizumab) is similar to Lucentis. Avastin is actually the larger "parent molecule" from which Avastin is derived.
Avastin is a drug that was actually developed for metastatic colon cancer...but has effects similar to Lucentis. It has however not been studied as extensively in eye disease. A study is currently underway...comparing Avastin and Lucentis. Results are anticipated in approximately 2011.

how frequently does Lucentis need to be given?

Frequently!
The good news is that Lucentis works very well...and in most patients...vision can at least be stabilized...but often improved...dramatically.
The bad news...is that Lucentis eventually gets absorbed from the eye...and the effect wears off.
When the initial studies were published in 2005...showing the great success of Lucentis...patients had received MONTHLY injections for TWO YEARS
In 2009...most retinal specialists try to tailor treatment to the individual patient...and to his or her response to treatment...in most patients...significantly less than 24 injections are required in the first two years

What are the current treatments available for "wet" macular degeneration?

Until very recently...the treatment of wet macular degeneration was not very successful.
Fortunately...the situation has changed.
In 2009...the treatment of choice, throughout the world...is with a drug called "Lucentis" or Ranibizumab.
This drug is a "monoclonal antibody fragment"...specifically engineered for wet macular degeneration.
Retinal specialists administer Lucentis as an injection into the eye.

what is "AREDS"?

"AREDS" refers to the "Age Related Eye Disease Study"...in which 3640 patients, ranging in age from 55-80y were studied for a period of 6 years.
The study found that patients with "dry" macular degeneration, who took a specific combination of vitamins...had a 30% LOWER RISK of developing "wet" macular degeneration.
As a result of this very well done study...it is now recommended that patients with dry macular degeneration take ocular vitamins.
Numerous different brands of ocular vitamins exist on the market. The key is to choose a brand that has the "AREDS" formulation...these are the only vitamins that have been proven effective.