The last two decades have witnessed many innovative developments in the field of eye surgery. Of these, the following five advances are considered the most important in improving vision for millions of people:
LASIK (Laser-Assisted in Situ Keratomileusis) has freed a large number of people from having to use glasses or contact lenses. It was 1991, when Stephen Slade and Stephen Brint in the US performed the first LASIK operation.
"LASIK is a technique which helps correct various refractive problems such as nearsightedness, farsightedness and astigmatism," says Dr Hinadree Datta, a professor of Ophthalmology at the Regional Institute of Ophthalmology, Kolkata, India. "In this technique, with the aid of a laser, the surface of cornea is precisely reshaped, thus enabling a better focusing of light on the retina (the light-sensitive inner layer of the eye)," Dr Datta explains.
Microphaco, a term coined by US ophthalmologist Randall Olson, has been another important advance in the field in recent years. It's a modified version of phacoemulsification - a popular cataract surgery technique, where the lens inside the eye is broken up by an ultrasonic device and then removed.
"In microphaco surgery, the cataract can be removed through a substantially smaller incision, compared with the traditional phacoemulsification surgeries, and this helps provide the patients with a far better visual outcome after cataract operation," says Dr Subrata Mitra, senior consultant ophthalmologist at the Tinplate Hospital, Jamshedpur, India.
He adds, "A 1.2-1.4 millimetre incision may be enough for the removal of cataract in microphaco, whereas in standard phacoemulsification surgeries, usually 2.4-2.8 millimetre incisions are required; and the smaller the incision, the lower the likelihood of post-operative refractive problems, such as astigmatism."
"Hence this procedure is gradually becoming popular in Europe, the US and other countries such as India," Dr Mitra comments.
Photodynamic surgery, or surgery using light energy, has also been a boon to many people who suffer age-related macular degeneration (AMD). AMD is a dreaded eye condition and a major cause of blindness in elderly people. In this condition, new blood vessels grow under the retina's central portion and with the progress of the disease, the light-sensitive cells in the central retina function abnormally, ultimately resulting in blindness.
"Photodynamic surgery was first developed to treat skin ailments, but in recent times it's also been advocated in ophthalmology, and this advance has led to a new avenue in the treatment of AMD," says Dr Bikram Saha, Assistant Professor of Medicine at the North Bengal Medical College Hospital, Darjeeling, India.
He explains, "With AMD, photodynamic surgery is used to destroy the abnormal blood vessels in the retina. Here, a light-sensitive dye is administered through injection and then with the aid of light (that is made to emerge on the specific areas of the retina), the dye is activated. The activated dye then destroys abnormal blood vessels in the retina and thus helps treat AMD."
"Application of photodynamic surgery in the treatment of AMD is a great advance in ophthalmology, because it's quite effective for cutting the risk of moderate and severe vision loss in certain cases of AMD," comments Dr Saha.
Endoscopic dacryocystorhinostomy (endoscopic DCR) is also a cutting-edge eye surgery. First described in 1989, endoscopic DCR has become a major operative procedure to help people suffering from recurrent infection and inflammation of the tear containing sac (lacrimal sac).
This condition is caused by the blockage of the duct (nasolacrimal duct), which carries tears from the tear sac to the nose. Endoscopic dacryocystorhinostomy is a minimally invasive operation to overcome the blockage.
According to the National Institute for Clinical Excellence, London, endoscopic DCR is a minimally invasive procedure used to bypass the nasolacrimal duct. Under local anaesthesia, an endoscope is inserted into the nose. Surgical instruments or a laser are used to create an opening between the nose and the lacrimal sac through the mucosa and intervening bone.
"Endoscopic DCR has become a popular surgical technique, because here, unlike the conventional DCR (in conventional DCR, the nasolacrimal duct blockage is bypassed through an invasive operative procedure), no external scar results and complications are substantially fewer," says Dr Datta.
Recurrent infection and inflammation of the tear sac is manifested with certain symptoms, such as excessive tearing or discharge from one eye, pain, redness or swelling of the eye.
Small-incision retinal surgery
For various ailments associated with the retina, such as retinal problems associated with diabetes, macular hole (a condition where there is hole in the central portion of the retina), or some types of retinal detachment, small-incision retinal surgery has yielded wonderful results.
"Small-incision retinal surgery can be medically termed as 25-gauge suture-less vitrectomy," says Dr Mitra. He explains: "Vitrectomy is an old procedure, in which vitreous humor (a jelly like substance inside the eye), is surgically removed from the eyeball. But in the new technique, vitrectomy is done, but with a very small 25-gauge incision and without any suture."
"Recovery time and risk of complications are significantly less with small-incision retinal surgery, and the post-operative outcome is quite impressive."
These five procedures have greatly helped further ophthalmology, but the progress of ophthalmic science is still ongoing, with various new and modified techniques arising; for example, zyoptics (a kind of refractive eye surgery) has come up as a newer version of LASIK.
"All these developments are fine; we must welcome the new advances in eye surgery," says Dr Saha. "But these techniques should undergo rigorous clinical trials, so that proper evaluation of safety and efficacy of the procedures can be done," he cautions.
- Dr Sanjit Bagchi, Health24, December 2006
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Ophthalmological Society of South Africa