Ophthalmology

Ophthalmology

Ophthalmology is the medical specialty concerned with the eyes and their relationship to the body. An ophthalmologist (also called eye physician and surgeon, oculist, eye doctor) is a medical doctor who has studied eye conditions and diseases for 3 to 6 years after medical school and medical internship before taking examinations set by the Royal College of Physicians and Surgeons of Canada or by the College of Physicians and Surgeons of Québec. Once qualified, an ophthalmologist becomes part of the general medical team, not only treating diseases and conditions of the eye but also helping to diagnose many general medical problems, including circulatory disorders (eg, high blood pressure and atherosclerosis), neurological disorders (eg, multiple sclerosis and stroke) and endocrine problems (eg, diabetes and thyroid disease). These conditions can be associated with blurred vision and other symptoms, and it is the ophthalmologist who often initiates not only vision-saving but also lifesaving treatments.

Modern Study of the Eye

The modern study of the eye as a medical specialty gradually evolved during the 1800s. Henry Howard of The Montréal Eye and Ear Institution was likely one of the first doctors in Canada to limit his practice to eye problems. His 1850 book The Anatomy, Physiology and Pathology of the Eye, based on his 4 years of practice in Montréal, was published before the invention of the ophthalmoscope in 1851. The ophthalmoscope, a small hand-held telescope for looking through the pupil of the eye, allows doctors to see inside the eye and to examine the retina and optic nerve, which are extensions of the brain. In 1864 Toronto doctors pioneered retinal photography by connecting an ophthalmoscope to a camera to photograph the retina of a cat, a first step in photographing the inside of the living human eye and a technique that today is essential all over the world in evaluating and treating patients with eye diseases.

In 1922 Dr Walter Wright pioneered the use of fascia lata (leg tissue) for repair of ptosis (droopy lids) in a manner that is still in use. The Canadian Ophthalmological Society was formed in October 1937, but it was not until the early 1940s that Dr Walter Wright at the University of Toronto set up the first in-Canada training program for ophthalmologists. Soon afterwards, Dr Harold Ridley, an Englishman, replaced an opacified lens (cataract) with a new clear plastic one (intraocular lens). Canadian ophthalmologists were among the pioneers to use these lenses.

As part of any complete eye examination, ophthalmologists take a history to find out if the symptoms relate only to a local eye disease or are manifestations of diseases elsewhere in the body such as stroke, brain tumour, diabetes, hypertension, rheumatic disease or cancer.

Technological Advances in Eye Care

Ophthalmologists can reconstruct many parts of the diseased eye. The diseased cornea can be replaced by a clear donor cornea in a corneal transplant operation - in 1955 the Eye Bank of Canada was set up as a joint project by the Canadian National Institute for the Blind and the Canadian Opthmalmological Society; superficial scars in the cornea can be evaporated off using the excimer laser; a clouded lens can be replaced by a clear plastic one in a cataract extraction and lens implantation operation; and glaucoma can be treated with newer medications, laser surgery and glaucoma surgery. Retinal disease can be treated with various lasers and with scleral buckling and vitreous cutting operations.

Fine membranes can be peeled off the ultrathin retina and new techniques allow for surgery even underneath the retina which is much thinner than cellophane. Fine wire-sized endoscopes the diameter of a fine needle that carry video and laser fibers allow a view and permit treatment of those hard to see areas inside the eye as well as in the orbit and up and down the tear canals. Wrinkles around the eyes can be lessened or wiped away with a specific laser technique and bags and sags around the eyes can be treated with ophthalmic plastic treatments.

General ophthalmic specialists are widely distributed all across the country, and subspecialists with special expertise in retinal and vitreous disease, cornea and external disease, glaucoma, neuro-ophthalmology, oculoplastics, pediatric ophthalmology, strabismus and refractive surgery practice in most major centres across Canada. Training centres at medical schools for ophthalmologists are located in Halifax, Québec City, Sherbrooke, Montréal, Ottawa, Kingston, Toronto, London, Winnipeg, Saskatoon, Edmonton and Vancouver.

The combination of technological advances and imagination in designing procedures has allowed Canadian ophthalmologists to lead in ophthalmic innovation. Operating microscopes now allow functional magnification: tissue can be repaired with stitches finer than a human hair and new techniques even allow for fine self-healing wounds that do not even require closure with sutures. Some intraocular lenses fold up for insertion into tiny wounds that may be smaller than 2.4 mm. Membranes more delicate than tissue paper can be cut, left or picked clean of scar tissue. It is even possible to operate underneath the retina, even though it lines the back wall of the eye.

In the Forefront

Technical advances and clinical data about contact lens technology emanate from Canada to around the world. Techniques for surgically modifying the shape of the eye to reduce or eliminate the need for glasses have been pioneered in Canada and ophthalmologists from around the world have flocked to Canada because of its leading role in initiating laser refractive surgery with the newest equipment and latest techniques. Canadians have been in the forefront in developing newer and safer techniques for cataract and lens implant surgery. Newer techniques for detection of glaucoma with the use of computerized tomography of the optic nerve head is being developed in Canada for use around the world.

Ultrasound biomicroscopy was developed at the University of Toronto and has given us insight into the physiology of accommodation and the pathophysiology of various forms of glaucoma. Three-dimensional ultrasound of the eye and orbit has been developed in London at the University of Western Ontario and allows ophthalmologists to visualize, measure and follow intraocular and orbital tumours so that these can be treated optimally and safely without early surgery, or allows the opthalmologist to more efficiently plan complex intraocular surgery.