Laser eye surgeries
Ophthalmic laser surgery was a significant development in ophthalmology over the past three decades. Several types of lasers may be used on different parts of the eye and have been helpful in treating many different types of eye diseases, and conditions.
What is a LASER and how does it work?
The term ‘LASER’ is an abbreviation for ‘Light Amplification by Stimulated Emission of Radiation’.
Various types of ophthalmic lasers are used to treat different types of eye conditions. Ophthalmic lasers are named according to the material contained in their plasma tube source.
In the most commonly used ophthalmic lasers, a powerful electric current is passed through a tube containing one of several gases (Argon, Krypton or Argon Fluoride) or a solid material (neodymium-YAG, Q-Switched).
Light Energy is produced and the laser emits a small uniform light beam which, when focused through a microscope or other lenses, produces either heat coagulation, tissue cutting, or ablates / evaporates certain eye tissues – as per the need of the patient.
OLDER Argon gas lasers emit a green or blue-green light beam, and is used to treat Retinal or Iris tissue, while the Krypton gas laser emits a red or yellow light beam to be used for treating other types of Retinal conditions. Both are less frequently used nowadays.
Solid state crystal lasers and diode lasers are commonly available too, and have other specific applications.
NEWER Q-Switched and YAG Lasers are more widely used to treat Retina and Iris Tissue conditions, as well as separating / breaking thin membranes.
Excimer (Excited Dimer) Laser is used during LASIK and PRK / Epi-Lasek / LASEK surgeries for Vision Correction and Enhancement of previous similar surgeries.
Femto-Second Lasers are used to separate layers of clear tissue so as to create Corneal Flaps for LASIK, Pockets for Corneal Inserts and Reshaping (SMILE), and entry wounds for corneal & Cataract surgery and Corneal Grafts, as well as Lens Fragmentation for Cataract Surgery.
What are the advantages of using ophthalmic lasers?
The ophthalmic laser allow patients to be treated without the risk of infection, in a relatively painless way with minimal discomfort, on an outpatient basis.
With their sophisticated microscopic focusing and delivery systems, ophthalmic lasers provide the ophthalmologist with precision and control not previously available with other surgical techniques. This precision, safety, convenience, and reduced cost allows more people to be treated successfully for an increasing number of eye disorders and diseases.
Which conditions can be treated with ophthalmic lasers?
Disease of the retina.
- Retinal tears or holes, which can lead to retinal detachment may be treated in early stages with laser coagulation, using an Argon or green laser.
Symptoms of retinal tears often include a sudden onset of flashes or floaters in one eye. Visual accuity may or may not be decreased.
Not all retinal tears are suitable for treatment with the laser. If retinal detachment has occurred, ophthalmic laser coagulation cannot be of much help, and an operative surgical procedure is usually performed, which may include intra-operative laser therapy.
- Diabetic retinopathy. This is a major cause of blindness. There are two major types of diabetic retinopathy. One form e.g. edematous, or background diabetic retinopathy, is characterized by leakage of small blood vessels in the retina, which then causes reduced vision. Advanced background diabetic retinopathy can lead to a second form, proliferative retinopathy, which is characterized by the growth of new blood vessels in the retina. This may lead to hemorrhage and fibrosis / scarring of the retina.
People with diabetic retinopathy may not suffer reduced vision in the early stages, and therefore regular eye examinations by an ophthalmologist are important, especially for people who have been diabetic for a number of years. Uncontrolled diabetes mellitus causes accelerated diabetic damage to the retina, leading to vision loss – Earlier than what the average diabetic patient may encounter.
- Macular degeneration. Newer types of Targeted YAG Lasers can be used to Rejuvenate the Pigment Epithelium Layer of the Retina. Other types of Laser targets Retinal tissue with the help of specific injected Dyes to selectively close Neovascular membranes & Vessel that leak to cause macular Oedema.
- Glaucoma is a disease which, affects at least two out of every hundred elderly Americans, and is even more prevalent in other population / ethnic groups.
In untreated cases, the nerve of sight (optic nerve) becomes damaged due to the buildup of fluid pressure inside the eye that remains too high for too long. Fortunately, loss of vision from glaucoma can be prevented or limited most of the time if the disease is detected and treated before noticeable damage occurs to the optic nerve.
Glaucoma, more than any other eye condition, needs to be detected early if treatment is to be successful, and vision loss to be limited.
- Open angle glaucoma.
- Angle closure glaucoma. This condition is less common and usually accompanied by pain, red eye, halo’s around lights, blurred vision, and occasionally nausea and vomiting.
The laser is used to create a tiny opening – iridotomy – in the peripheral iris of the eye to allow the occular fluids to circulate better and reduce acute pressure rises and the development of optic Nerve damage.
Surgical intervention with iridotomy, and Cataract Extraction may assist in control of the intra-ocular pressure, if it proves to be necessary and appropriate.
Membranes of the eye.
- Following surgery of the eye, e.g. cataract extractions, or as a result of disease, membrane clouding can obscure vision.
The Neodynium – YAG laser is used to open or dissolve these membranes. The Neodymium – YAG laser may be used before or after cataract surgery to open a hole in the Lens membrane or capsule which contains the lens of the eye.
The laser is however not used to remove cataracts, contrary to popular belief, it only assists in the surgical process.