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Good Pupil Diameter Key for Successful LASIK Surgery

Laser eye surgery, hugely successful for the great majority of patients, can fail if a subject’s pupils are too large.
   
Thus, a good eye doctor who wants to provide patients with LASIK surgery (short for laser-assisted in situ keratomileusis) to correct faulty vision – including nearsightedness, farsightedness and astigmatism – will carefully screen applicants for the procedure.

Expert Commentary: Michael Rosenberg, M.D. - 6/18/2009

If one looks critically at headlights, streetlights, digital clocks or similar localized light sources at night, most individuals will be aware of some halos and starbursts whether they have had LASIK or not.  These halos are ascribed to certain inherent imperfections (or aberrations) in the eye resulting in subtle vision issues that are not necessarily corrected by wearing glasses or contact lenses.  In the dark, when the pupil is larger to let more light in, the light entering the eye passes through the aberrations, resulting in the halos and starbursts. 

Modern laser surgery usually uses some type of “custom” treatment that attempts to eliminate or reduce aberrations in addition to reducing the patient’s near-sightedness or far-sightedness.  The diameter of such “custom” treatments is usually about 8 mm. (The diameter of non-custom “conventional” treatment is about 6.5 mm). Even when receiving “custom” treatments patients are counseled to expect an increase in halos and starburst immediately after the procedure due to acute tissue changes and dryness. In most patients, the halos and starbursts will gradually decrease and stabilize at a level that is not disturbing. Persistent night vision phenomena may be due to a persistent refractive error (that is residual near-sightedness or far-sightedness) or new aberrations induced by the treatment. The former may be corrected with retreatment, the latter may or may gradually resolve.

LASIK Surgery Can Cause Dry Eye Syndrome

While LASIK eye surgery in most cases results in vision improvement to 20/20 or better, an occasional subject becomes affected by a chronic condition in which the eye has a problem with lack of lubrication.
   
This condition is known as dry-eye syndrome. It can affect those who have not undergone LASIK surgery, a procedure that is not recommended for such people. Screening by eye surgeons is supposed to exclude all dry-eye sufferers from LASIK, but some get through and often experience a worsened condition after surgery.

Expert Commentary: Stuart Sondheimer, M.D. - 6/15/2009

Dry eyes affect many people, whether or not they have had Lasik. It is more common as we age and is more frequent in people who have rheumatologic diseases, such as rheumatoid arthritis,  and in people who have had chemotherapy for cancer.

In dry eyes, the glands that make tears no longer make enough lubrication to make the eyes comfortable. Some patients can no longer wear contact lenses; others find that their eyes feel dry, scratchy, and irritated.

Blog Post: Dr. Elliot Goodman, M.D. May 5, 2009

In a fascinating study in the journal Nature Structural and Molecular Biology,  scientists explored the creation of fat through a structure called fatty acid synthasase. While this is pure research with no immediate clinical application it does open a window into how fats are formed from carbohydrates. A deeper understanding of how this happens can ultimately lead to the development of inhibitors that would help block the conversion of carbohydrates into fat. This research always begs a somewhat difficult question. To what extent are people who overweight at fault. Or rather the question is how should a person feel about being overweight. This is an a critical question because how a person feels about their weight can go a long way to how they try to deal with it, either through diet, exercise, or surgery.

New Laser Eye Surgery Helps "Presbyopic" Patients

A new eye surgery technique has proven excellent at eliminating a common vision condition affecting most middle-aged and elderly people, a recent study showed.
   
The condition, known as presbyopia, starts to appear around age 40 and causes blurring in one’s near vision as the eye’s natural lens gradually loses its flexibility. A nearsighted person with presbyopia can’t see up close with his usual glasses or contact lenses, but is able to see nearby things clearly without them.

Blog Post: Richard Braunstein, M.D. April 28, 2009

What to Look for in a Laser Eye Surgeon. Laser Eye Surgery is one of the most remarkable advances in medicine care in the last 50 years. It has literally made us rethink how we approach heretofore untreatable eye conditions. It's hard to imagine that just a few years ago eye conditions such as near-sightedness, astigmatism and far-sightedness were untreatable conditions. We all thought we were destined to live with impaired vision with for the rest of our lives As an ophthalmologist (eye doctor for short), I was trained to correct vision with the subtle use of optical lenses - in short, glasses.

Blog Post: Dr. Elliot Goodman, MD April 27, 2009

So here is yet another story on the dangers of obesity. In this case several studies were reported in the journal of Neurology that points to the possibility that obesity puts people at greater risk for dementia, Alzheimer's Disease and the loss of brain function, in general. This Just adds another mark to the innumerable reasons -increased risk for heart disease, diabetes, cancer, to name a few - why it is critical to tackle the weight loss issue head-on.

Synchrotron X-Ray Research Being Used to Advance LASIK

British researchers using X-rays from a massive particle accelerator are investigating the human cornea and making discoveries that could help create the next generation of LASIK eye surgery – and even one day develop an artificial cornea.
   
Keith Meek, head of the Structural Biophysics Research Group at Cardiff University, and his colleagues have beamed special X-rays from the Synchrotron Radiation Source (SRS) in Daresbury and the Diamond Light Source in Oxfordshire onto both diseased and normal corneal samples to analyze the cornea’s structure of collagen protein fibers.

LASIK's Reality: Impermanent for Many

LASIK eye surgery effectively and safely corrects severe nearsightedness, the results lasting for at least 10 years – but a significant proportion of the procedures need to be redone during that time, a recent study revealed.

Moreover, only 40 percent of LASIK patients avoid the use of glasses altogether after surgery, and for a great many, there is some vision deterioration over the 10-year period, the researchers wrote in the American Journal of Ophthalmology.