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EYE HEALTH BREAK-THROUGHS

RECENT ADVANCES MAY HELP MANY ADULTS RETAIN OR REGAIN THEIR VISION

BY KAMALA THIAGARAJAN  


In September 2013, D. Kumar, 72, a Delhi-based retired engineer, ran into complications with the cataract surgery for his right eye. It ended up damaging the cornea.'For the next few months, I experienced great discomfort,' says Kumar, who currently heads a consultancy firm.'Fluids seeped from my eye constantly and I could barely see.' Post surgery, he sought fresh medical opinion and was told that he needed a corneal transplant to save his vision.

After securing a cornea that matched Kumar's, a surgeon replaced the damaged inner layer of the cornea with a new one, through a procedure called sutureless corneal transplant. 'It allows you to transplant single layers of the cornea, restoring vision in a range of cases,' says Dr Rishi Swarup, medical director and chief of cornea services, Swarup Eye Centre, Hyderabad, who performed the surgery. 'While previously 16 stitches were required, this is performed with a single suture (and in some cases, without any), hastening the healing process.' Kumar's recovery was rapid and dramatic. 'My surgery was at 3 p.m. and I was allowed to go home the same evening. I could actually see the roads when we drove back from the hospital,' says a thrilled Kumar, who has regained his vision fully. Along with sutureless corneal transplants, laser-guided surgery, intraocular lens implants and injections that can save your vision, a host of other breakthroughs are changing the landscape of ophthalmic treatments.  

'Blindness worldwide has dropped by around 40 per cent over the last 20 years,' says Dr Serge Resnikoff, an ophthalmologist in Geneva and spokesperson for the International Council of Ophthalmology. And yet, despite these advances, more patients need access to cutting-edge treatments. Says Dr R. Kim, chief medical officer and chief of retina services, Aravind Eye Hospital, Madurai: 'Access to revolutionary eye treatments can make a startling difference in restoring vision, but prohibitive costs remain a factor.'

The biggest advances have been made in the arena of diagnostics, says Dr Ronnie Jacob George, ophthalmologist and research director at Sankara Nethralaya, Chennai. 'We now have sophisticated high-resolution scans that make it possible to detect anything at almost a cellular level, adding to our knowledge of what goes on in the eye. This, we believe, will pave the way for innovation, transforming how eye ailments are treated in the future.'

Here are the advances that are now helping people see.

Glaucoma

According to the Glaucoma Society of India, this condition is the third leading cause of blindness in our country, affecting 12 million people over the age of 40. 'It's a silent, chronic disease, often associated with ageing,' says George. 'Excess fluid builds pressure in the eye, which can damage the optic nerve, leading to vision loss,' he explains. The key to preventing blindness due to glaucoma is early detection. 'Nearly 50 per cent of the cases amongst the Western population are diagnosed, compared to only 10 per cent in India,'says George.

Today, optic nerve scanning technologies such as OCT (optical coherence tomography) are widely available and helping detect and manage glaucoma. These sophisticated scans are able to examine both the front and back of the eye, and in the past five years, they've undergone a generational change with the resolution improving dramatically, from 5 microns to 20 microns, offering sharper imaging, say experts.

Glaucoma patients are usually prescribed eye drops to lower the pressure. But in many cases, this medication may not be effective. A laser treatment called SLT (selective laser trabeculoplasty) is now being used to treat glaucoma.'A laser light induces the draining of fluid, through a sponge-like meshwork,' explains George.'It's an outpatient procedure and may need to be repeated after six months. It doesn't cause a dramatic drop in eye pressure, but it does help reduce dependency on daily eye drops.'

There are other treatments that may be available in India soon. For example, Xen Gel Stent, in which minuscule stents are injected into the eye to relieve pressure. Also under research are medication-dispensing contact lenses (already tested on animals) that deliver medication up to a month. However, further research is required to determine their safety for humans.

'Any new technique that helps patients recover their sight or even retain what they have is great progress,'says Dr Navin Sakhuja, Delhi-based ophthalmologist and vitreoretinal eye surgeon, and member of the Delhi Ophthalmological Society and the American Academy of Ophthalmology.
Hormones may be another possible weapon to thwart glaucoma. A recent study found that women who take oestrogen-only hormonal replacement therapy (HRT) have a lower risk of glaucoma.'Prior work has demonstrated that exposure to oestrogen may lead to lowering of the intraocular pressure,' says study author Dr Joshua D. Stein, associate professor of ophthalmology, University of Michigan. Oestrogen may also protect the optic nerve and retinal nerve fibre layer tissue, which can become damaged from glaucoma. Researchers don't know if HRT can prevent disease progression in people with glaucoma; further research is needed.

Cataract

India's cataract burden is one of the highest in the world-74 per cent of Indians above the age of 60 are afflicted. As we age, the lens, made up of natural protein and water, tends to get clouded, blurring vision. Modern cataract surgery (in which the cloudy lens is removed and an artificial one is inserted) has been available since the '50s. Phacoemulsification surgery became standard in the '90s. It uses incisions smaller than in the past and doesn't always require sutures.

Today, a new laser-guided surgery makes it easier to treat cataracts. Says Swarup,'Earlier, the success of cataract surgery largely depended on the skill and experience of the surgeon. Lasers make it possible to make a much more refined incision in the capsule around the eye lens. There are no sutures and post-surgical healing is faster too.'

What's more, great advances have been made in the nature of the lens. Usually, intraocular lenses (IOL) are mono-focal-they allow you to see better at a distance and have one focal point. But they can be multi-focal too, allowing you to see objects both near and far. This has provided patients a much greater range of spectacle-free vision than ever before.

Suman Kumar, 68, a homemaker based in Hyderabad, was amongst the first few patients to receive this treatment in India. In 2014, Kumar noticed that she could no longer distinguish colours and her vision had dimmed perceptibly, even with glasses. After her left eye was operated, Kumar realized that she could watch TV or see objects at a distance, but could not read a book or do embroidery. When she went in for an operation in her right eye, the surgeon replaced her lens with a multi-focal IOL. 'I noticed the difference at once,' she says.'Today, I can easily thread a needle and I don't have to wear spectacles.' The multi-focal IOLs are expensive, though. The surgery can cost up to `1 lakh per eye.

Diabetic Retinopathy

A complication of diabetes, this causes blood to leak from small vessels in the retina, obscuring one's field of vision. Early detection and controlling blood sugar and blood pressure can help.'India has a large diabetic population and this ailment is a real threat,'says Kim.'Lasers were used earlier to halt the disease, but it wasn't possible to restore eyesight.' More recently, intraocular injections such as anti-vascular endothelial growth factor (VEGF) and steroids have shown positive results.

Ophthalmologists may inject these to reduce fluid accumulation or to block the growth of new blood vessels. Each injection (different types of anti-VEGF injections are available) can be prohibitively expensive-costing between `10,000 and `60,000, depending on the brand of the drug and the clinic where the procedure is done.

It is wise, however, for anyone with diabetes to visit their doctor annually.'Frequent screening and early detection can help prevent loss of vision,'advises Kim.

Macular Degeneration

Age-related macular degeneration (AMD) robs its victims of sight, either gradually or suddenly. 'An AMD patient retains peripheral vision,' explains Sakhuja.'He can see images from the corner of his eyes, but can't see objects directly in front of him.'There are two forms of AMD: wet and dry. 'The dry form is a natural consequence of ageing; the macular tissue thins out over time.' There is no cure or treatment for dry AMD, although this is one ailment where long-term prevention may help. There is a role for dietary supplements as well as lifestyle changes, such as giving up smoking, increasing orange and green vegetables and fruits (containing lutein) in the diet, and reducing exposure to UV rays.

Wet AMD occurs when abnormal blood vessels develop and leak beneath the macula. Vision loss in this case can be sudden and dramatic. The standard treatment for wet AMD is anti-VEGF injections. According to Sakhuja, these injections halt the progression of the disease and stabilize it. Though an injection in the eye sounds painful, the actual procedure takes less than a few seconds and is almost pain-free.

In March 2011, Delhi-based Jag Mohan Puri, now 80, managing director of a family-run education consultancy business, found that the vision in his left eye had dimmed perceptibly. Sakhuja, his ophthalmologist, diagnosed him with wet AMD in his left eye and dry AMD in the right. 'Along with medication, I was prescribed a series of injections in my eyes,' he says. Today, Puri has experienced remarkable improvement -he's able to read email and go about his daily tasks without any issues.  
Intraocular implants may soon make treatment easier. 'There is a possibility of an implant in the eye that constantly releases a small dose of anti-VEGF antibody, but these are under clinical trials and will probably be with clinicians shortly,' says Sakhuja.

Technology has made things easier for patients. Instead of handheld magnifiers or minuscule telescopic lens implants in the eye, devices like the iPad allow magnification with a single touch.

Dry Eye

As you reach your 50s, your eyes produce fewer tears. Over time, you may need drops to keep your eyes moist. There are two types of dry eye: The first type is caused by poor tear production, due to underlying systemic conditions like diabetes, rheumatoid diseases and oral medication for other illnesses. The second type is linked to faster evaporation of tears. Normally, after every blink the tear should be in your eye for 10 to 12 seconds. When the tears evaporate faster, say, in less than six seconds, it is called evaporative dry eye. This is common among computer users, particularly younger people. The main causes of this could be infrequent blinking, long hours of work, patients prone to acne, those with a dry skin and vitamin D deficiency.

'When you have a problem with the tear film in the eye, it's like the fogging of your windshield that needs defrosting,' says Dr Rohit Shetty, ophthamologist and translational scientist, Centre for Occupational Dry Eye, Narayana Nethralaya, Bengaluru. Use of technology worsens dry eye; blinking spreads tears across the eye surface but people blink less frequently when they use computers. Shetty's team has identified other causes for the condition, published in the 2015 issue of the International Journal of Biomedical Research. 'We've linked dry eye to vitamin D and B12 deficiency, both affect corneal nerves and are common in India,' he says. Deterioration of the corneal nerves induced by inflammation causes chronic pain and a gritty feeling in the eyes of people with low vitamin D. Some complain of red eyes causing embarrassment. In his research, Shetty linked the changes in the tear film to a condition called keratoconus (where the cornea becomes conical, a structural defect that threatens vision). In its advanced stages a patient may even need a corneal transplant.

The latest technology has aided diagnosis and treatment. Machines like LipiView (helps in observing the tear film and titrating the treatment) and LipiFlow (provides hot fomentation and massage to the eye) have helped immensely. LipiFlow unclogs the meibomian glands (that secrete tears in the upper and lower eyelids) allowing the natural flow of lipids to resume, enabling secretion of good quality tear film. The procedure could cost you `60,000-70,000 approximately.

'Washing dry eyes can only aggravate the condition. Today, there are immune-modulators, which reverse this condition and help the eye stay moist. Preservative-free drops also minimize the risk of chronic dry eye,' says Sakhuja.

'Dry eye is hardly the innocuous problem that it is considered to be,' adds Shetty.'It can create complications in the long run.'Managing dry eye is more like connecting the dots. Treating it requires a holistic approach, taking into account your overall systemic condition, addressing your nutritional deficiencies and medication. Your ophthalmologist can suggest the treatment best suited for you.     


THE STEM CELL PROMISE

'Stem cell treatments to reverse blindness present exciting possibilities, but these are still in a very experimental stage globally,' says Dr Ronnie Jacob George. 'At the moment, stem cells are being used successfully to repair injuries/trauma to the surface of the cornea.' The interesting aspect about this therapy is that you don't have to wait for a donor. The patient's healthy eye can serve as a potential site for stem cells as well. There are a small number of cells at the outer rim of the cornea called limbal stem cells. Limbal cells from the cornea of a healthy eye are extracted, cultivated in the lab and grafted onto the surface of the eye to repair the damaged portions. This treatment has benefited acid attack survivors, for whom the surface of the cornea is too scarred for a traditional transplant. 'A corneal transplant (necessary to regain some amount of the vision) was not possible earlier,' says George. This, he explains, was due to the risk of the new cornea getting scarred, as the mechanism to replace the outer layer of cells, in the eyes of the survivor, is damaged. However, by replenishing the stem cells, it is possible to repair the surface of the cornea and regenerate it. This has brought relief to people who suffer from other forms of cornea damage as well. 'We hope that in future the full potential of stem cells can heal and reverse all kinds of blindness.'

ADAPTED FROM AN ARTICLE BY LISA FIELDS.

 

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