By Netan Choudhry, M.D, FRCS and Jennifer George
The earliest cataract surgeries date back 4,000 years. Since it was first performed in ancient Egypt, India and Japan, cataract surgery has undergone a long process of evolution, leading to today’s modern procedures.
The need for cataract surgery has only increased over time. Cataracts are now one of the leading causes of vision loss in adults aged 55 and older. Over 2.5 million Canadians currently suffer from cataracts and this number is expected to double to five million by 2031. Fortunately, it is also one of the most treatable causes of blindness.
The lens of a healthy eye is circular and biconvex, bulging outward like the surface of a magnifying glass. It is also transparent, allowing light rays to pass through it. This transparency is integral to the proper functioning of the lens. Like the lens of a camera, the passage of light through the eye’s lens determines the clarity of one’s vision. In a healthy eye, light can travel through the transparent lens to the retina, where it is converted into neural signals delivered to the brain. These signals become the images one sees. In patients with cataracts, however, a clouding of the eye’s lens occurs, resulting in blurred and out-of-focus vision. For the retina to capture a sharp image, the lens must be clear, whereas having a cataract could be likened to seeing the world through a window covered in petroleum jelly.
Though cataracts can severely impair vision, treatment has greatly advanced in the last decade. Cataract surgery has become routine in Canada, with more than 250,000 procedures performed annually. It is also one of the most successful surgeries, with over 95 per cent of patients reporting improved vision afterwards. Until recently, the preferred method of removing cataracts in the developed world has been phacoemulsification. This technique utilizes ultrasonic energy to soften the dense lens material of the cataract, which is then extracted from the eye with suction and irrigation. In this traditional surgery, handheld blades are used to create incisions within the cornea to access the cataract. A surgical instrument is then used to manually create an opening in the lens capsule that holds the cataract. The goal is to make the incisions precise and the openings in the lens capsule as circular as possible, in the right location, and the correct size to accommodate the lens.
Recently these manual procedures have been performed in an automated fashion with the use of the femtosecond laser (FSL). FSL technology has been widely used in various refractive surgery applications in recent years. The approach utilizes photodistruption, which results from a focused beam of pulsed light energy. The focused pulse creates optical breakdown with significantly low pulse energy, thereby minimizing damage to the eye. Studies have examined the potential advantages of more precise corneal incisions and capsulotomy formation. The precision of FSL can allow a surgeon to create the circular opening with the exact intended size, shape and location, and clinical studies indicate that the opening is almost 10 times more accurate than the manual alternative.
With FSL, surgery is highly customizable. Patients will receive more precise treatment with gentler and easier cataract removal. And because FSL is less invasive, the procedure results in little to no discomfort. The added low-energy approach of FSL also results in faster recovery times, placing this new approach on the cutting edge of cataract treatment. With bladeless surgery offering individual precision, FSL can now provide patients with results that were hitherto unattainable.
