Innovations in Research
Here is a look back at more than fifty years of advancements in eye care and ophthalmology – and a glimpse at what’s on the horizon.
1960 – the first glaucoma implant (seton) is developed which allowed fluid to drain from the eye through a tube, thus lowering eye pressure. People with difficult-to-treat glaucoma now have an option to slow or even prevent vision loss as a result of their condition. Modifications of these devices continue to be used to treat glaucoma that is resistant to other treatments.
1967 – propranolol, a drug used to treat heart conditions and high blood pressure, is discovered to lower Intraocular pressure (IOP) when given by injection. Several more years of investigation and trial were required to develop a drop form which was safe and effective, but these drugs remain very important in glaucoma management.
1968 – Dr. J.E. Cairns introduces trabeculectomy as a surgical treatment to help lower intraocular pressure. This procedure creates a flap in the eye which allows excess fluid to leave the eye. It is still widely used to manage glaucoma.
1961 – the first use of fluorescein dye to visualize blood vessels in the retina is reported. This fluorescent dye allows the retinal blood vessels to be visualized and damage from diseases such as diabetes to be recognized and treated.
1967 – Dr. Charles Kelman revolutionizes cataract surgery by introducing a procedure called phacoemulsification (“phaco”) to remove cataracts. This procedure uses an ultrasonically vibrating needle to break up and remove cataract damaged lens material from the eye through a tiny opening, allowing much more rapid visual recovery after surgery. It took many years to develop reliable technology to allow widespread use of this procedure.
1970 – Radial keratotomy, a type of surgery that involved making a series of cuts into the surface of the cornea, the clear tissue which makes up the front of the eye, is used to correct myopia (near-sightedness).
1972 – The first air-puff tonometer is introduced. The air-puff tonometer uses a puff of compressed air to flatten the surface of the eye in order to measure eye pressure without the need for topical anesthesia. A modern version of the original air-puff tonometer can still be found in eye examining rooms today.
1978 – Timolol, a beta-blocker (a drug used to treat heart conditions), is approved for the treatment of glaucoma in eye drop format. Earlier versions of other beta-blocker eye drops were found to be toxic (poisonous) to the surface of the eye; however, timolol continues to stand the test of time and is still widely used today.
1979 – First reported use of lasers to treat glaucoma. This early approach was found to be effective for several years but eventually fails to control pressure in the eye. It has been replaced by newer laser techniques.
1978 – The Foldable Intraocular Lens is developed. This allows the lens implant, which replaces the focussing power lost after cataract surgery, to be placed into the eye through small incisions. This minimizes post-operative recovery time and improves vision after surgery.
1972 – Vitrectomy surgery is first successfully demonstrated. This procedure uses a miniature cutter which is housed in a needle to safely remove the vitreous from the back cavity of the eye. Vitreous is like a raw egg white and is involved in retinal detachments, diabetic retinopathy, macular holes, and several other serious eye diseases. Refinements of the equipment have resulted in cutters <½ mm in diameter which operate at speeds >7500 cuts/minute which allow precise shaving of the vitreous from the retina.
1980 – Development of highly accurate eye measurement tools and equations designed to improve accuracy of lens power selection begins.
Phacoemulsification becomes a more widely used procedure for cataract surgery. Coupled with a lens opening technique known as capsulorrexis, which was developed in Canada, phacoemulsification allows placement of lens replacements into the eye with great precision allowing accurate predictable vision correction after cataract surgery. This allows patients to enjoy clearer vision, faster.
1982 – first reported use of a laser to treat diabetic retinopathy. Still widely used to treat abnormal blood vessel growth in diabetes, the laser has prevented blindness in many thousands of patients worldwide.
1990 – Health Canada approves the excimer laser to correct myopia (near-sightedness) and astigmatism (blurred vision due to an irregular shaped cornea or lens inside the eye). This laser “evaporates” tissue in a controlled way allowing the cornea surface to be sculpted into a new shape.
1991 – Dr. Stephen Slade and Dr. Stephen Brint perform what is now known as LASIK surgery for the first time in the United States. This procedure is commonly used for vision correction today and involves creating a partial thickness flap in the cornea, then using an excimer laser to reshape the cornea in the bed of the flap before replacing the flap into position. This marked the beginning of the end of eyeglasses and contact lenses for thousands of people across the country.
1990 – anti-metabolites (5FU and mitomycin) are used during trabeculectomy procedures (a procedure that reduces eye pressure in people with glaucoma) to help reduce scarring after surgery and during wound healing. This significantly improves the success of the surgery.
1990s – computerized visual field analyzers become widely available. These machines improve the precision of measurement of peripheral (side) vison. This means physicians can more easily detect early vision loss from glaucoma and its progression.
1996 – adrenergic agonists are also introduced for intraocular pressure management. They work by increasing the flow of fluid out of the eye, thus lowering intraocular pressure.
1996 – prostaglandin analogues are first introduced as drops for glaucoma treatment. They work by increasing the flow of fluid out of the eye, thus lowering intraocular pressure. Together with adrenergic agonists and beta blockers, prostaglandin analogues form the mainstay of medical (drop) management of glaucoma today.
1993 – Optical Coherence Tomography (OCT) machines become commercially available. These machines use a low powered laser to optically image the retina and optic nerve noninvasively with resolution < 5 microns (5 microns is about the size of a single red blood cell). This allows accurate rapid detection of abnormalities within the retina from the early stages of wet macular degeneration to diabetic retinopathy as well as changes from glaucoma.
2000s – Wavefront-guided excimer surgery allows treatment of more complex vision issues like glare, halos and starburst patterns. By taking an individualized scan of each eye, wavefront-guided excimer technology can help develop a customized treatment for each patient – a true example of fitting technology to the patient, rather than fitting the patient to the technology.
2005 – anti-VEGF (vascular endothelial growth factor) medication becomes available, which means that, for the first time, people with wet AMD can have the disease arrested, often with improvement of vison. The drugs require regular retreatment to remain effective and must be given by injection into the eye which results in a profound increase in the demand for Ophthalmologist services.
2001 – The Selective Laser Trabeculoplasty (SLT) procedure is approved for glaucoma treatment. Unlike earlier laser glaucoma procedures, SLT does not produce scarring, and therefore can be used more widely in glaucoma treatment.
2006 – Lamellar corneal transplants are developed to speed recovery and improve visual outcome. These procedures involve selectively replacing only the layer(s) of the cornea which are diseased through techniques that split the cornea’s layers apart during surgery.
2010 – FDA approves the femtosecond laser. This laser can be used to create incisions in the cornea and lens with great precision and has the potential to further improve the outcome of cataract and other eye surgery.
2016 – Corneal crosslinking is developed to treat people with keratoconus, a condition in which the cornea (the surface of the eye) becomes weak, thin, and irregularly shaped. It uses ultraviolet light and riboflavin to alter the protein matrix within the cornea. The cross-linking procedure helps make the cornea more stable, significantly lessening the progression of the disease.
2015 – New generation micro-implants are developed for glaucoma. These devices (stents) are tiny tubes of various designs which are implanted within the fluid drainage meshwork in the front chamber of the eye. They allow excess fluid to be drained from the eye internally without the need of external drainage. This is much less invasive than current types of glaucoma surgery (trabeculectomy and setons), and these promise fewer side effects.
2015 – Anti-VEGF drugs are approved for the treatment of diabetic retinopathy and retinal vein occlusion. They provide significantly better visual outcomes than laser alone and have largely replaced the use of laser in treatment of diabetic macular edema.
2016 – Retinal surgery visualization takes a giant leap forward with the help of sophisticated visualization systems and “virtual reality” surgery which make surgery safer and allow outcomes not possible with earlier techniques.
2017 – FDA approves a gene therapy to treat a hereditary retinal disease. This revolutionary approach offers hope that vision loss will be slowed or prevented for those who have some types of genetic retinal diseases.
Advancements in imaging technologies are allowing Ophthalmologists to detect the signs of wet AMD before patients develop symptoms, allowing for closer monitoring and earlier treatment, which is vital to preserve vision.
Next generation anti-VEGF therapies that reduce injection frequency
2020 – A new anti-VEGF (vascular endothelial growth factor) drug is authorized in Canada for the treatment of neovascular (wet) AMD. Compared to previously available treatment options, this next generation anti-VEGF offers patients an extended period between doses, addressing the strong need for a treatment that reduces the burden of frequent injection and follow-up.
2022 – A new drug is authorized in Canada for the treatment of neovascular (wet) AMD and diabetic macular edema (DME). It’s the first treatment that acts by targeting both VEGF and angiopoietin-2 (Ang-2), two proteins that can cause the growth of abnormal blood vessels and/or damage to the normal vessels in vision-threatening retinal conditions like wet AMD and DME. The treatment helps patients achieve optimal vision gains while reducing the number of injections, alleviating the treatment burden for patients and their caregivers.
A look to the future of innovation in AMD
A high-dose anti-VEGF treatment is in development. Promising phase 3 clinical trial results have been presented that demonstrate strong durability, efficacy, and safety. If approved, this agent will provide patients with another option to treat wet (neovascular) AMD that achieves optimal vision gains while reducing the frequency of injections for patients.
Potential treatments are in development for geographic atrophy (GA) – a currently untreatable cause of vision loss in patients with advanced AMD. Phase 3 clinical trials for drugs that inhibit complement (C3 and C5), thought to be associated with lesion growth in GA, have shown promising results in slowing the progression of the disease.
Various other types of treatment, including gene therapy, stem cell therapy, and oral medications are in early investigational stages for the treatment of wet and dry AMD.
Home monitoring technologies, such as home optical coherence tomography (OCT) with relayed data directly to the eye care professional, are being studied in clinical trials. These technologies have the potential to help detect visual changes earlier and inform more individualzed treatment plans.
A team of Canadian researchers, spearheaded by McMaster University’s Dr. Varun Chaudhary, will undertake a comprehensive study to assess AMD on a national level. Known as the Radiographic Evidence study of Age-related Macular Degeneration, or R.E.A.D. study, it will examine a randomized selection of retinal images and biomarkers from around 8000 study participants (ages 45 to 85) to measure the disease over time. The R.E.A.D. study aims to provide a better understanding of the Canadian prevalence of AMD as well as genetic, behavioural, and environmental risk factors for the disease.
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