Information For Consent For Cataract Surgery

Transcription

1 Information For Consent For Cataract Surgery Your Ophthalmologist has diagnosed you with a visually significant cataract. The following handout will explain your condition and give you the information needed to make an informed consent regarding cataract surgery. If you have further questions after reviewing this handout please let the office know so that we may address your questions and concerns. BASIC EYE ANATOMY: The lens of your eye functions very much like the lens in a camera and focuses incoming light rays onto the retina. The lens is contained in a very thin, membranous bag called the capsule. The capsule is held in place by tiny filaments called the zonules. The retina, at the back of the eye, acts much like film in a camera by gathering the visual information and sending it to the brain. If the image presented to the retina is blurry, it will send a blurry image to the brain and you will see things blurry. The lens must be clear and have the correct power to focus images at distance. The natural lens is flexible in the early years and can adjust focus to near objects (this is called, ACCOMMODATION). This ability to accommodate is slowly lost with age as the lens stiffens, beginning in the early 40 s. This loss of accommodation, called PRESBYOPIA, is why reading glasses become necessary. A refractive error means that the eye does not focus light sharply on the retina and the image that is seen is blurred. Refractive errors include MYOPIA (or "nearsightedness"; too much focusing power, so there is more blurring of objects at distance), HYPEROPIA (or, "farsightedness"; not enough focusing power, so nearer objects are more blurry), and ASTIGMATISM (blurring of near and distant objects due to irregular curvature in the cornea, lens, or both. REFRACTIVE ERRORS: A Refractive error means that the lens and cornea working together do not focus the light directly on the retina. This is treated with either glasses, contact lenses or refractive surgery. Because of irregularities in the cornea (astigmatism) most eyes require a weak corrective lens for optimal vision after surgery. Large amounts of astigmatism will not go away with cataract surgery with standard lens implants. Toric lens implants are special lenses that can correct astigmatism. Foldable lenses are the latest technology and can be implanted through an incision approximately 3 mm in size. The advantages of foldable lens are related to the smaller wound size and include less astigmatism and a shorter healing time (about 3 weeks). WHAT IS A CATARACT? When the natural lens of the eye loses its usual transparency, this is called a cataract. Cataracts cause blurring of vision, distortion, and glare. Cataracts can also change eyeglass prescription. New glasses may temporarily help the vision in patients with cataracts. The decision to remove cataracts is made when the blurring becomes significantly symptomatic and when surgery would be expected to improve the vision. A cataract is not: A film over the eye Spread from one eye to the other Caused by overusing the eyes A cause of irreversible blindness Common symptoms of a cataract include: Painless blurring of vision Glare and light sensitivity Poor night vision especially driving

2 Doubling of vision in one eye Fading or yellowing of colors Needing brighter light to read WHAT CAUSES CATARACTS? Cataract formation is part of the normal aging process. The formation of cataracts may be accelerated by factors such as ultraviolet light exposure, smoking, laser eye surgery, diabetes, and steroid containing medications. Sometimes infants are born with cataracts called congenital cataracts. Trauma to the eye can also cause a cataract in a previously normal eye. There is no current medical therapy such as eye drops or diets available to prevent or treat cataracts. Fortunately, cataract surgery has a high success rate. WHEN SHOULD CATARACTS BE REMOVED? Based on your symptoms you and your ophthalmologist should decide together when surgery is appropriate. It is not true that cataracts need to be ripe before they can be removed. Cataract surgery can be performed when your visual needs require it. Sometimes it is medically necessary to remove cataracts for the overall health of your eyes. You must decide if you can see well enough to do your job, enjoy hobbies and activities, drive safely*, read or watch TV in comfort. *Driving standards exist that set the MINIMUM visual acuity required to drive, but you may not feel comfortable driving even if your vision meets these minimum standards. WHAT IS CATARACT SURGERY? Cataract surgery is usually done as an outpatient procedure at a surgical clinic under local (needle) or topical (drops/gels) anesthetic. You must be able to co-operate fully with your surgeon during the procedure if topical anesthetic is used. Please request the needle anesthetic if you feel you will be unable to hold your eye steady, relax your eyelids open or are very nervous about your eyes and the procedure. Using a microscope for magnification, a small hole is made in the eye and an ultrasound probe is used to break up the cataract into tiny fragments. These fragments are then vacuumed out of the eye leaving behind the capsule. An artificial intraocular lens implant (IOL) is then placed in the capsule. Your vision may be blurry for the first hours. Do not be concerned by this. You will be required to take medicated drops before and after the surgery. Most patients will require bifocals or reading glasses after surgery, but these glasses are not usually very strong. This need can be significantly decreased with premium intraocular lenses in many patients. CHOOSING YOUR LENS IMPLANT (IOL) Standard IOLs are designed to correct vision at ONE distance. Simple myopia and hyperopia can be corrected with standard IOL s. Usually focus for distance vision is chosen and reading glasses are worn when needed. Sometimes focus for near is chosen and distance glasses are worn. The lenses covered by Alberta Health are high quality injectable lenses. These lenses do not correct all post-operative refractive concerns. Premium IOLs offer more post-operative refractive options as outlined below. TORIC IOLs may be used to correct corneal astigmatism. Standard IOL s do not correct corneal astigmatism. Alternatively, corneal astigmatism may be correct by glasses, contact lenses, or corneal surgery. Presently, the cost of the TORIC lens and the additional assessment are not covered by Alberta Health Care. The cost of the lens is $ (no tax) per eye, and there is a $400 (+tax) fee for the premium lens calculations necessary to fit this lens. This $400 fee applies whether you have one eye done, or both. TORIC IOL s do NOT provide accommodative focus. Simple reading glasses will still be required. TORIC lenses are designed to reduce astigmatism significantly BUT do not ELIMINATE it completely.

3 Loss of accommodation occurs with normal aging and as a result of standard cataract surgery. This is treated with: reading glasses when the lens implants are focused for clear distance vision, monovision (one eye is set for distance vision, and the other eye is set for near vision), bifocals, standard lens implants focused for near vision only and glasses are worn for distance vision, or Premium PRESBYOPIC IOLs are implanted. Presently, the cost of the Presbyopic IOLs and the additional assessment are not covered by Alberta Health Care. The cost is $ per eye (Restor lens), plus a $400(+tax) premium lens calculation fee. Presbyopic Restor IOLs do not correct astigmatism. RESTOR TORIC IOLs correct for astigmatism and provide some accommodation for both near and distance vision. These lenses are not covered by Alberta Health Care. Restor Toric IOLs cost $ per eye, plus a $400(+tax) premium lens calculation fee. Alberta Health Care funds the cost of the standard, high-quality, foldable IOL and will credit this amount to you if you select a premium IOL. Some other provinces do not even cover the cost of a foldable IOL and patients are required to pay for these. We would be happy to provide you with more information regarding premium IOL s if you are interested. Please confirm prices with our surgical booking coordinator when booking your surgery, as they may change. MEASURING YOUR EYES Your eye must be measured so that your ophthalmologist can choose the appropriate focusing power of your IOL regardless of whether you choose a standard or premium IOL. The power of your IOL must be accurate to achieve the optimal visual result. This power varies with each individual and is different for each eye. HOW DO YOU MEASURE MY EYES? There are two ways to measure eyes for IOL power; ultrasound (A-scan) and laser (IOL Master). We prefer to perform both and compare the results to get the most accurate measurements possible. Alberta Health covers the cost of the A-scan, but not the IOL Master. The IOL Master testing is an optional uninsured service. The IOL Master uses advanced laser technology to precisely measure the eye prior to cataract surgery. You will be given the option of enhancing your preoperative assessment by the IOL Master. The IOL master fee is $200(+tax). In most cases, either method of testing will allow permanent implantation of an intraocular lens at the time of surgery. The accuracy of both tests is affected by patient co-operation when the measurements are being taken. Previous refractive surgery such as Lasik, RK or PRK can seriously affect the measurements for implants. **Please let us know if you have ever had this type of refractive surgery. ** No absolute guarantee can be made about the refractive or visual results. The lens implants will not always result in 20/20 vision or complete freedom from glasses. POSSIBLE COMPLICATIONS As with any kind of surgery, there are risks associated with this procedure. Complications from cataract surgery may include any of the following: Blurry vision: Corneal swelling and astigmatism can reduce vision after surgery. The swelling is usually temporary (lasting several days, up to several weeks), but some people are prone to prolonged or permanent swelling due to some weakness in the corneal anti-swelling pumps. Astigmatism will usually settle down within a few weeks following surgery and any remaining astigmatism can be treated with glasses.

4 Refractive errors: Despite our best efforts, significant myopia (nearsightedness), hyperopia (farsightedness) or astigmatism may exist following cataract surgery. This may be corrected with glasses, contact lenses, refractive surgery, or may require IOL exchange. Differences between the post-operative focus in a pair of eyes may be particularly difficult to tolerate even with glasses and may be more likely to require IOL exchange. IOL exchange is a separate surgical procedure and carries with it significant risks. Cataract surgery can make astigmatism worse or better. Foldable lens technology allows implantation through a smaller self sealing incision. The advantages of foldable lens are related to the smaller wound size and include less induced astigmatism, increased wound stability and strength, as well as a shorter healing time (about 3 weeks). Double vision: Cataract surgery may cause temporary double vision. In less than 1% of cases double vision will be permanent. It may then require prism glasses or muscle surgery to correct the double vision. Topical anesthesia with drops or gels, rather than a needle, is much less likely to causes double vision. Ptosis (droopy eyelid): The upper eyelid has a delicate tendon that may be stretched as a result of any eye surgery. Patients who have previously weakened this muscle by minor injury, such as prolonged contact lens, wear may be at increased risk. Post-operative ptosis will sometimes improve spontaneously, but often requires an eyelid tuck procedure which is performed under local anaesthetic. Ptosis will occur in about 1% of patients. Secondary cataract: One of the most common complications is the formation of scar tissue on the capsule behind the artificial lens. This is called a secondary cataract and is sometimes referred to erroneously as the cataract growing back. A routine laser treatment called a YAG Capsulotomy easily treats this capsule opacification. This laser treatment is painless and quick. It is required in about 20% of patients. It carries with it a small risk of increase in eye pressure and retinal detachment. Pressure rises: It is not unusual for the pressure in the eye to rise after surgery, resulting in some discomfort. This is usually temporary and may require medication on a short-term basis. Pressure problems are more frequent in patients with glaucoma or in patients who are prone to glaucoma. Retinal disease: Retinal detachment can be associated with cataract surgery and can cause severe visual loss. The symptoms of a retinal detachment are floating dots, flashing lights, and a curtain of vision loss approaching from the outside into the central vision. Retinal detachment should be treated as soon as possible. Retinal swelling (macular edema) may reduce vision after cataract surgery. This may require additional tests on the eye, eye drops, oral medications or, rarely, injections of medication into or around the eye. Pre-existing eye problems such as macular degeneration can limit our success with cataract surgery. Bladder medications: Certain medications that reduce bladder neck spasm and help urination can have serious effects on the eye during cataract surgery. The most frequent offender is Flowmax. This medication causes poor pupil dilation and a floppy iris during surgery that can interfere with the surgeon s ability to remove the cataract and significantly increases the likelihood of intraoperative complications. Please let us know if you are currently on this type of medication or if you have EVER taken it. Certain special precautions must be taken before and during the surgery. Severe complications: Fortunately, these are rare. The rarest is irreversible loss of vision of the eye. Rupture of the delicate capsule can occur in eyes with certain congenital cataracts, dense cataracts, glaucoma, or in eyes that have sustained previous trauma. Infection in the eye after surgery can be the most serious complication and can result in total blindness and loss of the eye. Symptoms include pain and increasingly blurry vision. The most common time to develop an infection is between 2 and 7 days after surgery.

5 Infections are treatable in most cases, but MUST be brought to our attention RIGHT AWAY for the best possible outcome. ATTN: ALL CONTACT LENS WEARERS All SOFT contact lenses must be removed 1 WEEK before pre-operative lens assessment (Ascan) measurements. All HARD contact lenses must be removed 2 WEEKS before pre-operative lens assessment (Ascan) measurements. It is very important to have your contact lenses removed, because the cornea (front of your eye) is altered when wearing contact lenses. The cornea needs to be free of any contact-lensinduced changes before pre-operative measurements and surgery for optimal post-operative results.