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The Evolution of Cataract Surgery: The Most Common Eye Procedure in Older Adults

The Evolution of Cataract Surgery: The Most Common Eye Procedure in Older Adults

Teaser: 

Lorne Bellan, MD, Chairman, Department of Ophthalmology, University of Manitoba, Winnipeg, MB.

Cataract surgery is the most common refractive surgical procedure performed on aging individuals. Major advancements in surgical and lens technology have led to enormous increases in surgical volume because of the improved safety profile and outcomes. Current research holds the potential for restoring full vision, including accommodation, without the need for glasses in the near future.
Key words: cataract, lens, refractive, vision, phacoemulsification.

The Evolution of Cataract Surgery

The Evolution of Cataract Surgery

Teaser: 

Lorne Bellan, MD, FRCSC, Acting Department Head, Department of Ophthalmology, Misericordia Health Centre, Winnipeg, MB.

In addition to the clinical presentation and diagnosis of cataracts, a summary of the development of cataract surgery is presented. Indications for cataract surgery are now based on subjective visual impairment rather than measured visual acuity. Cataract surgery can now be done safely through 3mm self-sealing incisions with excellent results and rapid recovery.
Key words: cataract, lens, phacoemulsification, visual acuity, red reflex.

Cataract Surgery May Cut Crash Risk

Cataract Surgery May Cut Crash Risk

Teaser: 

Cataracts are the leading cause of blindness in the world and account for 15% of blindness in Canada. The condition, which results in deficits in acuity and contrast sensitivity and increased disability glare, is present in half of adults over the age of 65 years. Older drivers with cataract are more likely to have a history of recent driving accidents compared with older drivers without impaired vision, yet it has not been determined whether the surgical removal of cataracts--a highly successful treatment--reduces the likelihood of crashing. Investigators set out to determine the impact of cataract surgery on the crash risk for older adults in the years following surgery, compared with that of older adults with cataracts but who opted not to have surgery.

The prospective cohort study recruited 277 patients aged 55 to 84 with cataract, 174 of whom elected to undergo surgery. Researchers followed the patients for four to six years and compared vehicle crash occurrence involving patients who elected to have surgery versus those who did not.

Results showed that people who underwent surgery were 53% less likely to be involved in a car crash than those who did not have surgery, which translated to five crashes per million miles of travel among recipients of surgery compared to nine crashes per million miles for those who declined surgery. However, the authors, aware of the study's limitations, caution against the inference that surgery can make people better drivers. Patients who opted out of surgery may have had other medical risk factors that influenced both their decision to avoid the procedure and their risk of car crashes. Therefore, while the study may indicate that driving performance of older drivers with cataracts might improve after surgery, the threat of selection bias prevents more firm conclusions.

Source

  1. Owsley C, McGwin G, Sloane M, et al. Impact of cataract surgery on motor vehicle crash involvement by older adults. JAMA 2002;288:841-9.

Serendipity and the Origin of the Lens Implant in Cataract Treatment

Serendipity and the Origin of the Lens Implant in Cataract Treatment

Teaser: 

In 1942, a young British flight surgeon, Ridley, made an outstanding discovery that was to shape the future of cataract treatment. Cataracts result from the clouding of the lens of the eye, which leads to blurred vision. As with the lens of a camera, the lens of the eye functions by focussing light rays onto the retina at the back of the eye, which then transmits this visual information to the brain. For the light to pass through and reach the retina, the lens must remain clear. Cataracts result when the natural lens of the eye becomes cloudy; they are not the product of a growth or the accumulation of film over the eye.

While examining injured fighter pilots, Ridley noted that when plastic slivers from the shattered windshield of an airplane cockpit entered the eye, some pilots had a severe reaction, whereas other pilots had no reaction at all. At the time, the accepted belief was that any foreign material entering the eye would cause a severe reaction until it was removed. Ridley wanted to understand why some pilots showed no reaction to the presence of a piece of plastic in their eye. Further investigation led him to realize that it was only the pilots of Spitfires who did not suffer any complications, whereas pilots flying all other British fighter planes--including captured German pilots flying Messerschmitts--were all severely affected. The young surgeon then discovered that Spitfire plastic came from a different company, ICI, that produced a type of plastic material, polymethyl methacrylate, which could be tolerated by the human eye.

When the war ended in 1945, Ridley turned his attention to cataract surgery. Treatment at the time involved removing the diseased cataract lens and giving the patient thick, heavy glasses that limited their peripheral vision and magnified objects by 30 %. Ridley decided that a better technique for cataract treatment would be to replace the human lens with a lens made of the plastic that he had discovered during the war. On 19 November 1949, at St. Thomas's Hospital in London, he performed the first lens implant on a cataract patient.

Today the treatment of cataracts still relies solely on surgical techniques; there is no medication or diet that can stop a cataract once it has begun to form. A cataract may develop rapidly over a period of a few months or it may grow very slowly over several years. Typically, this process only occurs in a single eye, although eventually, often after months or years, a cataract may develop in the second eye. Most cataracts are related to aging, although they may also be congenital, the result of a medical problem such as diabetes or of a trauma to the eye.

A cataract rarely causes damage if it is left in the eye, except in cases in which there is blurred vision. There are very rare cases, however, of cataracts, when left in the eye long past the stage of blindness, causing inflammation and glaucoma. With the current methods of removal, surgery can be performed successfully at any stage of cataract development.

The only treatment for a cataract is the removal of the cloudy lens. There are various methods of surgically removing a cataract, and the specialist must decide which method is most suitable for each individual patient. For a description of the three main surgical procedures that are available for cataract extraction, and a list of the advantages and disadvantages of these techniques, please see the full article by Dr. Marvin Kwitko on our web site at www.geriatricsandaging.ca.

Dr. Marvin Kwitko performed his first lens implant operation at Bellechasse Hospital in Montreal in 1967. In 1968 he joined St. Mary's Hospital, and under the former chief, Dr. Gaston Duclos, continued this work there. Dr. Kwitko has trained more than 350 surgeons from Canada, the U.S. and abroad. He is currently the Chief of Opthalmology at St. Mary's Hospital in Montreal and an Associate Professor of Ophthalmology at McGill University.

New Technology Removes Cataracts and Improves Vision

New Technology Removes Cataracts and Improves Vision

Teaser: 

Kim Wilson, BSc, MSc

Cataract patients may now choose to have a multifocal implantable lens which corrects for distance, intermediate and near vision. During surgery, the patient's cataract or cloudy crystalline lens is removed and replaced by the foldable multifocal lens which then unfolds once positioned in the eye.

"This lens is significant to the elderly", said Dr. Allan Slomovic, Clinical Director of the Cornea and External Ocular Diseases at the Toronto Hospital (Western Division), and the Program Director in the Department of Ophthalmology at the University of Toronto. Dr. Slomovic is one of eleven ophthalmologists originally performing this surgery in Canada, and he says "this foldable lens allows for a very small incision of about 3.2 mm, which allows the eye to heal faster and the patient recovers their vision quickly."

Other foldable lenses are available, but the multifocal lens has the added advantage of correcting for distance, intermediate and near vision. The multifocal lens has a series of zones with different refractive powers, allowing the patient to see a range of distances. Each zone has different refractive powers, with zones one, three and five allowing the eyes to focus on objects at a distance, while zones two and four allow focusing of near objects.

The multifocal lens was developed by Allergan Inc. in California.