HEALTH & FITNESS

Beams of benefit
Laser therapy has revolutionised the treatment of eye diseases. Several common eye conditions can be treated and even diagnosed with help of lasers
Dr R. Kumar
Once a miracle of science fiction, today lasers are a practical tool being used in the effort to restore or preserve good vision. Lasers have become as essential to the eye specialist as the scalpel is to a surgeon.

Breakthrough to identify future Alzheimer's sufferers
The role of the immune system in defending the brain against Alzheimer's disease has been revealed in a study identifying 11 new genes that could help to trigger the most common form of senile dementia.

Health Notes





 

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Beams of benefit
Laser therapy has revolutionised the treatment of eye diseases. Several common eye conditions can be treated and even diagnosed with help of lasers
Dr R. Kumar

Once a miracle of science fiction, today lasers are a practical tool being used in the effort to restore or preserve good vision. Lasers have become as essential to the eye specialist as the scalpel is to a surgeon. A beam of light can reshape a cornea to improve its focus, create a channel within the eye to relieve the intraocular pressure of glaucoma or cauterise tiny haemorrhages or burn some unwanted tissue in the retina to restore vision.

Laser therapy has revolutionised the treatment of eye diseases. It has emerged the most significant intervention in ophthalmic practice. Several common eye conditions - cataract, diabetic retinopathy, age-related macular degeneration, glaucoma, eye-tumours, retinal holes, lachrymal block and vision problems like myopia can be treated with lasers. It can also destroy tumours, bands, unwanted blood vessels and unhealthy tissues in the eye.

Kinds of lasers

Lasers used in eye are of several types like argon, krypton, diode, dye, Nd yag laser, excimer etc. These are used for burning/destroying tissues with thermal, photo-chemical and ionizing effects. The surgery does not entail the risk of infection, can be done in OPD setting and gives precision and control to surgeon.

Lasers also play an important role in early diagnosis of several conditions. Thanks to con-focal laser ophthalmoscope, with which the scientists can study naturally occurring retinal fluorescence, which could serve as an early-warning of glaucoma, macular degeneration and other serious eye diseases. It can detect death of retinal cells early, caused by acute infection, toxin, glaucoma or trauma, which was not possible in the past. It can also help researchers to provide an early warning of the onset of Alzheimer's disease, by enabling the detection of death of cells in the retina.

Glaucoma treatment

Laser use is essential in the management of acute as well as chronic glaucomas. A simple office procedure called laser iridotomy, can prevent or treat narrow-angle glaucoma-a severe, acute form of the disease. In this type of glaucoma, the iris of the eye is pushed forward, blocking the channel (angle) that normally allows aqueous fluid to drain. The resulting rise in intraocular pressure causes an acute attack of glaucoma, which may permanently damage the optic nerve. Also, eye specialists can treat resistant cases of chronic glaucoma by performing argon laser trabeculoplasty (ALT) or selective laser trabeculoplasty (SLT), to improve the drainage and control pressure in the eye. If left untreated, glaucoma (also called kala motia in Hindi) can lead to permanent blindness.

Damaged cornea

Loss of vision due to corneal injuries and infection is common in India. But a simple procedure to heal the scars has been eluding the eye surgeons. Some surgeons conventionally repair corneas, damaged by burns, acids, accidents, other trauma or pterygium with the help of human amniotic membrane. However, inflammation and scarring are frequent side-effects of this surgery. Lasers have opened new vistas to manage such cases through photo-chemical tissue bonding (PTB) of the amniotic membrane. PTB-treated eyes have less scarring, inflammation and neo-vascularisation (growth of new blood vessels) than the surgically operated eyes.

Retinal problems

Lasers are frequently required to correct or treat retinal problems. It is used to treat many retinal diseases, including diabetic macular edema, proliferative diabetic retinopathy, vitreous bands, age-related macular degeneration, vascular occlusions, central serous retinopathy (CSR) and retinal holes or tears. Supra scan multi-spot laser is a new laser in the management of diabetic retinopathy, which is the leading cause of blindness in India, touted as the diabetic capital of the world. It also helps in other conditions, including retinal vein occlusion, neo-vascular glaucoma, and retinal tears.

To repair a retinal tear or hole, eye surgeon may use a high-energy laser to heat small pinpoints on the retina that then create scar tissue which binds (or "welds") the retina to the underlying wall of the eye. This prevents retinal detachment; a condition that can result in sudden, painless loss of vision. Lasers can also shrink abnormal new blood vessels that are bleeding into the vitreous in diseases such as diabetic retinopathy. This is essential to preserve central vision. Other retinal conditions that are benefited with use of lasers include:

Retinopathy of prematurity in infants.

Closure of retinal microaneurysms, and peri-vascular leakage.

Focal ablation of extrafoveal choroidal neovascular membrane.

Creation of chorioretinal adhesions surrounding retinal breaks and detached areas.

Pigment abnormalities such as leakage from central serous chorioretinopathy.

Ocular tumours

Cataract surgery

This is the commonest cause of blindness in India, which is, however, curable.

Contrary to popular belief, most cases of the cataract surgery involve use of phaco-emulsification as of now (ultra-sound based energy) and not lasers. A new technology called femtosecond lasers guided by optical coherence tomography (OCT), is a new kind of treatment. In this, the laser is used to make corneal incision to make a precise cut. It adds to wound integrity and further improves the visual outcome with reduction of surgically induced astigmatism. Further steps like capsulorhexis (making an outlet in the lens capsule), fragmentation of the hard lens (reduces the risk of damaging capsular bag/ zonular fibres) and separation of fragments, are also done with the help of lasers. Laser capsulotomy procedure may also be necessitated in certain cases when a membrane develops after several months of cataract surgery.

Some surgeons are over-enthusiastic about the use of lasers and predict an end to the era of phaco surgery in near future.

The writer is a Chandigarh-based eye specialist

Goodbye glasses

Goodbye to glasses Unsightly glasses have always been a nightmare for young girls and boys in India. The procedure of reshaping the cornea with the help of lasers, called LASIK, has become popular in this country. It reduces refractive errors and is fairly safe and effective. Before undergoing a refractive procedure, you should carefully weigh the risks and benefits based on your own personal experiences. Don't be influenced by friends who have had the procedure or interested doctors encouraging you to do so. If you're coping well with glasses, don't rush to have surgery.

Benefits of LASIK surgery

Perquisites include: Above 18, healthy, no infection, glaucoma or dry eyes, not suffering from any chronic disease.

Nearly 90 per cent of patients get good vision after LASIK.

LASIK is associated with very little pain.

Vision is corrected almost immediately or by the next day after LASIK.

No bandages or stitches are required.

Adjustments can be made years after LASIK to further correct vision.

After LASIK surgery, most patients have a dramatic reduction in use of eyeglasses or contact lens. Many patients no longer need them at all. However, it is not 100 per cent successful, 100 per cent of the time.

Problems may occur when the doctor cuts the flap, which can permanently affect vision.

It can rarely cause a loss of "best" vision.

Constant glare can be annoying.

Other problems include seeing halos around images, difficulty in driving at night, fluctuating vision and dry eyes with constant discomfort or redness.

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Breakthrough to identify future Alzheimer's sufferers

The role of the immune system in defending the brain against Alzheimer's disease has been revealed in a study identifying 11 new genes that could help to trigger the most common form of senile dementia. Scientists believe the findings support the belief that a failure of the immune system to clear out tangled proteins and other "debris" accumulating in the brain of Alzheimer's patients may be central to how fast someone succumbs to the disease.

The same regions of the genome have also been found to play a role in multiple sclerosis and Parkinson's disease, indicating that there may be common genetic factors behind the diseases, said Gerard Schellenberg of the University of Pennsylvania.

"Healthy cells are good at clearing out debris, thanks in part to the immune response system," Professor Schellenberg said.

"But in these neurodegenerative diseases where the brain has an inflammatory response to bad proteins and starts forming plaques and tangle clumps, perhaps the immune response can get out of hand and do damage," he said.

The 11 genetic factors linked to Alzheimer's doubles the number of genes known to play a role in the disease. Scientists hope to use the information to develop new drugs and to identify those people at greatest risk of developing the brain disorder.

Alzheimer's disease is affecting an increasing number of people as the population ages. One in three people over 65 today will die with dementia more than half with Alzheimer's but the number of patients with dementia will more than double to 1.7 millions by mid-century.

The international study, published in Nature Genetics, collected genetic sequences from nearly 75,000 people in 15 countries in order to tease out the genetic factors that appear to raise the risk of developing Alzheimer's.

The Independent

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Health Notes
Rheumatoid arthritis ups heart disease risk

Washington: A new study has revealed that rheumatoid arthritis patients may be more likely to suffer from heart problems, early menopause. Eric Matteson, Mayo Clinic, Minnesotta, said the study showed the high-disease burden on the joints in the first year of disease. That already is a strong predictor of cardiovascular disease subsequently, and that seems to be mitigated as time goes on if the disease burden can be reduced too. In other research, a Mayo team looked at a common virus called cytomegalovirus, a bug many people get and do not even know they have.

They found correlations between rheumatoid arthritis patients' immune response to the virus and the development of myocardial disease.

Matteson said that if it turns out that there is this relationship, then it may be that one way to spot patients who are at higher risk for heart disease would be an immune profile or biomarkers related to the cytomegalovirus and its associated immune activation signalling.

Matteson said that another study found that women with rheumatoid arthritis and early menopause menopause before age 45 also seem to be at higher risk of heart disease. About two-thirds of patients with rheumatoid arthritis are women, and researchers have long studied possible hormonal influences on development of the disease. ANI

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