a. overview of retinal laser treatment

b. overview of laser treatment for glaucoma and narrow angles

c. overview of laser treatment for posterior capsule opacity

d. preparing for laser treatment

The retina is a thin, light-sensitive tissue layer at the back of the eye. A healthy retina is critical for normal, clear vision. Light rays are focused onto the retina through our cornea, pupil and lens. The retina converts the light rays into impulses that travel to the brain via the optic nerve. The brain then translates these messages into the images that we see.

Retinal holes or tears typically occur when the vitreous gel that fills the eye pulls on the retina. This can occur with aging or after eye surgery, and people may notice floaters or flashing lights in their vision. Some people are predisposed to retinal holes and tears because they are very myopic (nearsighted) or have areas of thinning in the peripheral retina. Retinal tears and holes can lead to retinal detachment, which can subsequently cause blindness if not treated in a timely manner.

Laser treatment, specifically called “Barrier Laser” or “Laser Retinopexy”, is recommended to seal or “spot-weld” the area around the tear or hole before it develops into a retinal detachment. The laser treatment does not have any effect on floaters or flashes. Sometimes, if the areas of thinning or tears are very extensive, multiple sessions of laser may be required.

Macular edema occurs when damaged blood vessels in the retina allow fluid to escape into the retinal tissue and cause it to swell. The macula is the very center of the retina and is responsible for central vision and color vision. A frequent cause of macular edema is diabetes, although it can also occur in uveitis, retinal vein occlusion, and other diseases.

Laser treatment may be recommended to decrease the amount of macular swelling, which may help to stabilize and hopefully improve central vision. This type of laser, referred to as “Focal retinal laser”, is typically not painful and can be completed within several minutes. Multiple sessions may be required, which may be a few months apart.

Blood vessels in the eye can become damaged in many diseases. Commonly, it can occur in diabetes, retinal vein occlusions, retinal vasculitis, sickle cell disease, and other conditions. When blood vessels in the back of the eye become damaged, this prevents oxygen and nutrients from getting to the retina. This is called “ischemia”. The retina tries to fix this problem by growing new blood vessels. Unfortunately, these new blood vessels are abnormal and grow like weeds onto the surface of the retina. They do not help to bring oxygen or nutrients, but instead they bleed into the eye and pull on the retina.

When there is retinal ischemia, laser treatment called “Pan-retinal Photocoagulation” can significantly reduce the chance of new abnormal blood vessels growing and help other abnormal vessels to regress or shrink. This can prevent further vision loss, and in some cases, help patients to regain vision. Retinal ischemia is a serious condition, and without treatment, there is a significant chance of permanent blindness. Typically, this type of laser requires multiple sessions before treatment is complete.

The laser treatments are usually done with local anaesthetic or numbing eye drops. The pupils are also dilated with drops. Sometimes, an anesthetic injection is given just under the surface of the eye for additional pain prevention.

A lens is then placed on the surface of the eye to focus the laser, and the patient is asked to position their chin and head at the laser machine. This looks similar to the slit lamp examination machine that is used to look at the eye, except that a laser is attached. Most patients find the laser light to be very bright. It is very important to keep one’s eye still and not move during laser treatment, so the laser can treat only the intended area. This minimizes any risk of vision loss as a result of laser. The laser session typically takes 5-10 minutes and is usually associated with mild discomfort.

Afterwards, the vision may feel very dark for a few minutes, and then will slowly recover over the next 5 minutes. Patients may be given artificial tear drops to help with any irritation they feel afterwards. There is no restriction on activity after laser treatment, and people usually feel back to their baseline by next day or two.

Laser treatment is generally, but not always successful. It is possible that the eye disease is too severe, and vision can continue to worsen despite laser, or further treatments may be required. There is a 1-2% risk of developing scar tissue or wrinkling on the central retina after laser treatment, which can cause distortion or require surgery to fix. Extensive laser treatments referred to as “Pan-retinal photocoagulation” or PRP, which are typically used in patients with abnormal retinal blood vessels, can cause a decrease in night or peripheral vision, or swelling in the macula. Very rarely, laser treatment can cause permanent pupil dilation and glare. If a patient moves during the laser procedure, they may notice a permanent dark spot in their central or peripheral vision.

Glaucoma is a condition that can cause vision loss when the intraocular pressure (IOP) damages the optic nerve. Open angle glaucoma is the most common type of glaucoma and can be treated with Selective Laser Trabeculoplasty (SLT) – a medical office procedure that helps to lower intraocular pressure (IOP).

During the laser treatment, short pulses of low-energy light are delivered to the cells of the structure in your eye that is responsible for pressure balance (the melanocytes in the trabecular meshwork). The cells in these structures heal and rebuild, and as they rebuild, the intraocular pressure is lowered. The light is targeted so it does not affect other structures in your eyes. This laser is 90% successful in lowering the IOP and lasts for 2-3 years on average. It is safe to repeat the laser.

Narrow angles is a risk for angle-closure glaucoma, which can occur suddenly (acute angle closure glaucoma) and more gradually (chronic angle-closure glaucoma). Both acute and chronic angle closure can lead to high pressure in the eye and vision loss due to damage to the optic nerve (glaucoma).

Some people have narrow angles but no glaucoma. In in this situation, the iris is very close to the drainage angle in their eye, or the angle between the iris and the cornea is narrow. Although there may not be any damage to the nerve, (no glaucoma), having a narrow angle is a risk for angle closure glaucoma. The risk of developing glaucoma if you have a narrow angle is 10%.

Laser peripheral iridotomy is performed to create an alternative outflow pathway for the aqueous fluid in the eye. This is a medical procedure during which the laser creates a small hole in the iris, which allows aqueous (fluid at the front of the eye) to travel directly from where it is produced (beside the lens) to the anterior chamber and then the outflow angle This alternative pathway for aqueous fluid is prevents or can treat “pupillary block” in eyes with narrow angle or angle-closure glaucoma.

Selective Laser Trabeculoplasty (SLT) is 90% successful in lowering the IOP and lasts for 2-3 years on average. It is safe to repeat the laser. The risks of the procedure include inflammation, raised pressure in the eye, and cornea swelling which are rare and usually temporary. IOP is checked 30 minutes following the SLT procedure in order to ensure that the IOP is not elevated and to provide treatment if required.

Laser peripheral iridotomy is a safe and very successful procedure. In some cases, the laser peripheral iridotomy has to be repeated. Many patients will experience mild blurred vision and discomfort for 1-2 hours after the procedure. In 1-2% of cases, a transient rise in the intraocular pressure (IOP) above 21 mmHg (normal IOP is <= 21 mmHg). This is treated with drops and rarely, oral medications. The IOP is checked 1 hour after laser peripheral iridotomy in all patients in order to detect this IOP rise and treat if required. Sometimes a small bleed can occur beside the laser hole. The ophthalmologist may apply some light pressure to the eye if this is seen at the time of the laser. This minor bleed resolves by itself. We do not recommend stopping aspirin or other blood thinners before or after the laser procedure. Rarely patients can experience transient glare, halos, line,s spots and shadows after laser peripheral iridotomy. These visual symptoms are uncommon and usually resolve by 6 months.

If you experience problems after your laser, please contact your ophthalmologist.

During cataract surgery, your ophthalmologist removes the cataract (cloudy lens) ad places an acrylic intraocular lens (IOL) on the posterior capsule or thin membrane that used to envelop the natural lens. In <5% patients who have had cataract surgery, this posterior capsule can become cloudy or opacified (posterior capsule opacity) and may cause the vision to be blurred or hazy. Posterior capsulotomy is a laser procedure that makes a small opening in the cloudy posterior capsule opacity and clear the vision again. Posterior capsulotomy is preformed 4 months or longer after cataract surgery.

Laser posterior capsulotomy is safe and usually does not result in any complications. Risks are low but include retinal hole or tear, retinal detachment, mild inflammation in your eye, shift in the intraocular lens (IOL) (very rare) and minor rise in intraocular pressure.

Your ophthalmologist will carefully examine the IOL position, intraocular pressure peripheral retina 1 month after laser capsulotomy to ensure that no retinal holes, tears, detachments have occurred and that your IOL is in position.

If you experience flashes, floaters, decreased vision or a curtain in your peripheral vision after laser capsulotomy, please contact your ophthalmologist for an eye check sooner than your scheduled 1-month appointment.

Laser treatments are performed in the office or in the hospital.

No preparation is necessary at home. Please continue to use any drops prescribed by your ophthalmologist.

If you are booked for a laser treatment at St. Joseph’s Health Centre, you will be given an appointment day and time for the laser treatment at the eye clinic. Please bring your health card to the appointment.

When you arrive at the hospital a nurse will place drops into your eye. Once the drops have worked, the nurse or ophthalmologist will place freezing or numbing drops into your eye and your ophthalmologist will perform the laser treatment.

If you had a laser peripheral iridotomy performed, you will be asked to wait one hour for an intraocular pressure (IOP) measurement.

A follow-up appointment will be booked to check your eye 1 month after the laser treatment.

If you are booked for a laser treatment at the office, please arrive on the day of the appointment with your health card.

When you arrive at the office, an ophthalmic technician will place dilating drops into your eye. Once the eye is dilated, your ophthalmologist will freeze or numb your eye with drops and sometimes with a small injection just under the surface of your eye. Your ophthalmologist will then perform the laser treatment.

You will be able to go home shortly after the laser treatment.

A follow-up appointment will be booked to check your eye 1-2 months after the laser treatment.

Cataracts are treated with an outpatient surgical procedure. Typically, this procedure lasts about 15-20 minutes. Although you are awake for the surgery, topical freezing drops are applied, and sedative is given to ensure you are pain-free and relaxed throughout the procedure.

During the procedure, your ophthalmologist can remove the cataract is removed by making a small incision at the edge of the cornea, at the front of the eye and then using ultrasound energy to break up the cataract into small pieces and removing each small piece from the eye.

After removal of the cataract, a synthetic intraocular lens is inserted into the eye. The IOL replaces the focusing power of the natural lens. IOLs can focus at a pre-set distance (monofocal IOL) or can focus at multiple distances (multifocal IOL). Your ophthalmologist will discuss the different IOL options with you and will recommend the most appropriate option for your eyes. (Not all IOLs options are possible in each individual situation).

Cataract surgery is a very successful surgery and risks are small; however, like any surgery, cataract carries a risk of bleeding 1/1000, infection 1/1000 and retinal detachment 1/100. Other less common risks include swelling of the retina (cystoid macular edema), and IOL dislocation or persistent swelling or inflammation at the front of the eye. In rare situations, the entire cataract cannot be removed at the time of cataract surgery and a second eye surgery is required to remove the rest of the cataract.

All patients will have temporary and mild inflammation at the front of the eye which is treated with topical steroid drops after surgery. Some patients can have a transient rise in intraocular pressure (IOP) after cataract surgery.

Cataract surgery will not restore decreased vision because of other eye conditions such as corneal conditions, macular degeneration, macular scarring or epiretinal membrane, glaucoma, or diabetic retinopathy.

Your ophthalmologist will talk with you about the risks and benefits of cataract surgery.

The time to have cataract surgery is when the cataract is affecting the vision enough to interfere with your normal lifestyle.

Cataract surgery is a very successful operation: 95% of patients have a successful result.

As with any surgical procedure, complications can occur, and some are severe enough to limit vision; however in the large majority of cases, vision and quality of life are improved with cataract surgery.

The best choice of lens implant for you will also depend on any other eye conditions that you may have. Your ophthalmologist will recommend the best intraocular lens for you when you during your first cataract assessment and this recommendation may be modified once specialized eye measurements are performed.

Your vision after cataract surgery and IOL recommended will depend on whether you have eye conditions such as dry eyes, glaucoma, macular degeneration, diabetes or previous retinal problems. Please discuss any questions your ophthalmologist and our surgical booking specialist.

Most people choose an monofocal IOL that helps to focus vision at distance, which means that glasses are needed to read up close. Sometimes people correct one eye for distance and the other eye for a closer point (reading or computers). (This type of correction which is different in both eyes is called “monovision correction”).

Multifocal IOLs help to correct vision at more than one distance. Your ophthalmologist can discuss with you whether or not you are a candidate for a multifocal IOL.

This intraocular lens (IOL) is a lens that usually provides very good distance vision. It is an excellent lens. This is the only IOL covered by OHIP.

Upgraded intraocular lenses include aspheric IOLs, Toric IOLs, multifocal IOLs (with or without Toric component) and extended depth of focus IOLs.

Aspheric intraocular lenses (IOLs) provide clearer and sharper images, day or night. For the majority of patients, these lenses may improve vision for varying light conditions such as night vision and foggy/rainy conditions.

The Toric IOL is an intraocular lens (IOL) which can correct astigmatism and may be recommended for those who have a clinically significant amount of astigmatism.

Astigmatism is when the front part of your eye (the cornea) is shaped more like a football than a basketball.

This causes images to be focused at two different points. The result is blurred vision at all distances. Therefore more lens power is needed to correct at one axis over the other. Astigmatism can usually be corrected with glasses for distance and near vision.

The Toric IOL is designed to work with the natural shape of your eye to correct the astigmatism. For people with clinically significant astigmatism, the Toric IOL will make you less dependent on glasses for distance vision after cataract surgery.

The Toric IOL does not correct presbyopia (the ability to see at near); you will need to wear glasses for near vision tasks such as reading.

Presbyopia is the medical term for patients requiring reading glasses or bifocals to see near objects. Multifocal intraocular lenses (IOLs) make you less dependent on glasses for all distances after cataract surgery.

Although these IOLs provide good vision at all distances, some patients may still prefer to wear a weak pair of reading glasses for specific tasks (such as working on a computer or reading very small print).

There is a higher chance of glare and halos around lights at night than with standard IOLs. Less than 5% of patients may experience intolerable glare and halos with multifocal IOLs. Multifocal IOLs reduce contrast sensitivity, which may reduce vision at night or in foggy conditions. When this does occur, most people adapt and do not notice this after a few weeks to months.

Some, but not all patients are candidates for the MFIOL.

This IOL is similar to the multifocal lens but uses technology to reduce glare and haloes. This IOL provides a range of vision from distance to intermediate (or computer distance). Patients may still need to wear a weak pair of reading glasses for fine print.

Similar to the Multifocal IOLS, patients may have a higher chance of glare and halos around lights at night than with standard IOLs and may have reduced contrast sensitivity.

Some, but not all patients are candidates for the extended depth of focus IOL.

This intraocular lens (IOL) combines the technology of the Multifocal or extended depth of Focus and Toric IOLs to correct both presbyopia and astigmatism in a single surgical procedure. This is a potential choice for people with clinically significant astigmatism who would like to be less dependent on glasses for most distances after cataract surgery.

To help you choose the most appropriate IOL (intraocular lens) for your eyes, various tests and calculations are performed in order to measure the length of your eye and the front curvature of your eye. We use the most up to date technology for these measurements. You will be booked for eye measurements at the office on a day which is at least 2 weeks prior to your cataract surgery.

Both eyes will be measured at the same time.

We recommend that you use artificial tear drops 3-4 X per day for 2 weeks prior to these measurements, in order to smooth the surface of the eyes – which will improve the accuracy of these measurements.

Your surgeon will use these measurements to determine the best intraocular lens (IOL) to implant during cataract surgery. Some of these tests are not covered by OHIP and are listed below.

This is the traditional method of measuring the eye to determine which power of intraocular lens (IOL) to place in your eye at the time of cataract surgery. This is the only eye measurement that is covered by OHIP.

The IOL Master is the latest in laser technology for taking precise measurements of the eye and is more accurate than any other method. This test is recommended for all patients regardless of the type of IOL to be implanted.

This extremely accurate test is recommended for all intraocular lenses and is a necessary test if you choose a Toric, Multifocal, or extended depth of focus IOL.

The corneal topography and waterfront aberrometer measure the surface curvature of the eye (the cornea) and can improve visual outcomes postoperatively by measuring astigmatism, spherical aberration, higher order aberrations, and investigating irregularities in corneal curvature.

This is a valuable test for all intraocular lenses and helps your ophthalmologist determine if you would benefit from a Toric IOL. If you choose a Toric IOL or Multifocal IOL, this test provides necessary data to calculate which strength of Toric IOL is best and at which axis it should be placed. and helps determine if a Multifocal or extended depth of Focus IOL would be appropriate for you.

You will receive a package of information from the office before surgery which will include information about the surgery, intraocular lenses, prescription for eye drops, calendar for eye drops, forms to fill out for the hospital or for Kensington Eye Institute before surgery and instructions about what to do on the day of surgery.

Two (2) weeks before cataract surgery, you will need to decide which IOL you would like to have implanted at the time of surgery, so this IOL can be ordered and ready for your surgery day.

You will need to start taking an anti-inflammatory drop (Nevanac) and antibiotic drop (Vigamox or moxifloxacin) 3 days before your cataract surgery. Please follow the instructions on your prescription for these drops.

Please also continue any other drops that you normally use, including dry eye drops and glaucoma drops.

If you have any questions about pre-operative drops, please call our office and talk to our surgical specialist.

Please continue other medications as you normally would prior to cataract surgery and talk to your family doctor if you have any questions.

Our surgical booking specialist will call you 1-2 days before surgery to confirm your surgery time and can answer any questions that you may have.

Please do not eat or drink anything after midnight on the day before your cataract surgery.

On the day of surgery please take your blood pressure and heart medications that you normally take in the morning with a sip of water. If you have diabetes, please talk to your family doctor about how to take your medications before and after cataract surgery.

You should arrive at the hospital 2 hours before your scheduled surgery time and at KEI 1 hour before your scheduled surgery time.

When you arrive at the hospital, please bring your health card and credit or debit card (if you have chosen a upgraded or non-OHIP IOL). After registration, you will be directed to the preoperative area, where a nurse will perform medical screening and will start eye drops in the eye which is to have surgery (antibiotic, steroids, anti-inflammatory and dilating drops).

When it is time for your surgery, you will be escorted or wheeled into the operating room. The doctor and nurses will ask you which is going to have surgery and the eye will be marked. The surgical bed will then be reclined into a flat position. Your eye will be numbed with eye drops and you will be given a medicine to help you relax through an intravenous or IV (by the anesthetist or anesthesia assistant).

You will be awake and very relaxed during surgery. If you need more medication to relax, this can be added during the cataract surgery.

At the beginning of surgery, the eyelid and skin around the eye will be washed with a disinfecting solution called poviodine and then a drape will be placed over your face and upper body, with a small opening over the eye to have surgery. A lid holder or speculum will then be placed in the eye to have surgery. During the eye surgery, you may see light and movement during the procedure, but you will not see what the doctor is doing to your eye. You will feel touching and pressure at times as well as liquid being dropped on the eye. At the end of the surgery, the lid holder and drape will be removed, eye drosp will be placed on the eye and a shield will be taped on the eye.

After the surgery the surgical bed will be brought to a sitting position and you will go to the postoperative or recovery area, where you will rest for about 15-30 minutes. . Your IV will be removed and you will be given a time for an eye check with your surgeon before you go home.

At the eye check-up (same day of surgery), your vision, intraocular pressure and front of the eye will be checked to make sure everything is as expected after your surgery. Your ophthalmologist will provide any specific instructions for you and will give you an appointment time for the week after surgery.

Your vision will be blurred for after the surgery and can remain blurred for a few days. The vision.

You will have to use eye drops after surgery. Your ophthalmologist will give you a sheet with instructions for the first postoperative week and a calendar for the next 4 weeks after cataract surgery. Sometimes the instructions on the calendar are modified. Please follow your ophthalmologist’s instructions for these drops.

Sometimes your intraocular pressure can be slightly high after cataract surgery. You may be given additional drops for this.

Always wash your hands before placing drops in your eye.

Avoid getting soap or water directly in the eye.

Do not rub or press on your eye.

Please wear glasses (sunglasses or your old glasses) during the day (especially when you are outside) and an eye shield when you sleep to protect your eye.

It is very important to do everything to prevent infection in the first 2 weeks after cataract surgery.

Your ophthalmologist will talk with you about how active you can be soon after surgery.

It is recommended to limit any vigorous exercise in the first 2 weeks and to gradually increase activities over the next 2-3 weeks.

Do not go swimming for 4 weeks after cataract surgery.

Cataract surgery and IOL options
https://www.beyondcataracts.ca/

Vision simulator for patients with cataract surgery and different IOL options
https://tecnisvisionsimulator.com/

Alcon Toric Patient Brochure
https://visionportal.ca/wp-content/uploads/2020/04/Toric-Patient-Brochure-ENG-GL-TOR-17-CANE-22332.pdf

Alcon AcrySof IQ Brochure
https://visionportal.ca/wp-content/uploads/2020/04/AcrySof-IQ-Brochure-ENG-GL-NIQ-19-CANE-1084-vFinal-1.0.pdf

Cataract Patient Brochure
https://visionportal.ca/wp-content/uploads/2020/04/Cataract-Patient-Brochure-Unbranded-Double-Page.pdf

Alcon PanOptix Patient Brochure
https://visionportal.ca/wp-content/uploads/2020/04/PanOptix-Patient-Brochure-ENG-GL-PNO-17-CANE-1742b.pdf