The study, led by a researcher at the John A. Moran Eye Center at the University of Utah, included 1,618 people with proliferative diabetic retinopathy (PDR) and end-stage renal disease (ESRD) and 954 diabetic patients without any eye or kidney disease.

PDR is the most common cause of legal blindness in working-age adults in the United States, accounting for 10 percent of new onset blindness overall. Diabetes is the leading cause of ESRD.

The researchers found that people with a copy of mutant EPO gene have an increased risk of developing PDR and ESRD.

"We know that the development of PDR and ESRD in diabetic patients can be inherited. Although genetic factors are known to be important in the susceptibility [or resistance] to these complications, until now, the genes involved have been mostly unknown," study leader Dr. Kang Zhang, director of the division of ophthalmic genetics at the Moran Eye Center and an associate professor of ophthalmology and visual sciences, said in a prepared statement.

The study was published online May 5 in the Proceedings of the National Academy of Sciences.

This finding may affect the use of EPO in treating patients with anemia, Zhang said.

EPO is used extensively to help in the production of red blood cells when treating patients with anemia resulting from renal failure or chemotherapy. In the United States, erythropoietin represents one of the largest single drug expenses for the Center for Medicare & Medicaid Services, approximately one billion dollars per year," Zhang said.

"Patients with anemia due to chronic renal disease [many of whom have diabetes] who receive frequent dosing of EPO to maintain higher hemoglobin levels have a higher rate of cardiovascular complications than patients who maintain a lower hemoglobin level. A similar effect of EPO on accelerating the decline of kidney function had been suggested by earlier studies. Our study suggests that caution may be warranted when maintaining higher hemoglobin concentration using exogenous EPO treatment in diabetic patients, as it might accelerate progression to PDR and ESRD."

Study co-author Dr. Dean Li, from the Program in Human Molecular Biology and Genetics at the University of Utah, added: "Though there is no proven pharmacologic treatment for diabetic vascular eye diseases, inhibiting the growth of unwanted blood vessel growth using antibodies directed against vascular endothelial growth factor [anti-VEGF therapy] has been advocated. This genetic study suggests that future therapeutic strategies need to consider blunting the effects of erythropoietin in addition, or as an alternative, to an anti-VEGF strategy."

More information

The U.S. National Eye Institute has more about diabetic eye disease.

A recent study in the journal Ophthalmology found that women with diabetes have about a 70 percent increased risk of developing the most common form of glaucoma -- primary open-angle glaucoma -- compared to women without diabetes.

"The study supports the notion that type 2 diabetes is associated with an increased risk of glaucoma," study lead author Dr. Louis Pasquale, co-director of the glaucoma service at the Massachusetts Eye and Ear Infirmary and an assistant professor of ophthalmology at Harvard Medical School, said in a prepared statement.

Primary open-angle glaucoma affects an estimated 2 million Americans, according to the U.S. National Eye Institute, and it is one of the leading causes of blindness.

Yet the link between diabetes and glaucoma hasn't been proven conclusively.

"There are a number of things, like diabetes, that appear to be a risk factor in a lot of population studies, but the association between diabetes and glaucoma is somewhat controversial," explained Dr. Joel Schuman, chairman of the department of ophthalmology at the University of Pittsburgh School of Medicine and Medical Center, and the director of the UPMC Eye Center.

Another study, also published in Ophthalmology, failed to find a link between diabetes and glaucoma in a trial that included almost 4,000 people from the Netherlands.

But, Pasquale's study was significantly larger, including more than 76,000 women enrolled in the 20-year-long Nurses' Health Study. And, the available evidence is convincing enough for the American Diabetes Association to conclude that the risk of glaucoma is increased in people with diabetes.

Glaucoma occurs when there's a gradual increase in the normal fluid pressure inside the eyes. This causes damage to the optic nerve, resulting in vision loss and blindness. Early detection and treatment can help prevent serious vision loss. About 50 million Americans are at risk for vision loss from glaucoma.

Schuman said there are a number of ways that diabetes could increase the risk of glaucoma. One way is by causing elevation in pressure within the eye. Or it's possible, he said, that diabetes could increase the susceptibility of the optic nerve to damage.

He said there's also one form of glaucoma that's known to be directly related to diabetes -- neovascular glaucoma. In this type of glaucoma, there's a reduction of oxygen supply to the retina, which causes the retina to send out signals for more oxygen and for new blood vessels to form. When these new blood vessels form, they cause scarring and block the normal drainage system in the eye, causing pressure to build up in the eye.

The most important thing someone with diabetes can do to protect their eyes is to get regular eye exams, Schuman said. Glaucoma generally has no early symptoms.

"There's no way to detect glaucoma without an exam, and the only way to prevent the loss of vision from glaucoma is to treat the disease early. You can't get back nerve damage that's been lost," he said.

Diabetes specialist Dr. David Oyer, of Northwestern Memorial Hospital in Chicago, said he recommends that people with diabetes have their eyes checked once a year by an ophthalmologist for glaucoma and other serious eye diseases associated with diabetes.

"The most important thing for reducing your risk of complications is to keep your blood sugar down both pre- and post-meal," Oyer said. He also recommends getting your A1C level checked every three to six months and keeping that number below seven, preferably below 6.5. A test of A1C (also known as glycated hemoglobin, or HbA1c) provides a snapshot of your average blood glucose control for the past two to three months, according to the American Diabetes Association.

Schuman also said regular exercise might help. "Exercise is good for the eye, just as it is for the rest of the body. Regular, vigorous exercise does lower eye pressure and probably affects circulation to the eye," he said.

More information

To learn more about glaucoma, visit the National Eye Institute.

"Some patients stabilize after only a few injections, and some require several injections, but the results are very encouraging," Dr. Peter A. Campochiaro, a professor of ophthalmology and neuroscience, said in a prepared statement.

The study included 20 patients with macular edema due to central retinal vein occlusion and 20 patients with macular edema due to branch retinal vein occlusion. They were randomly selected to receive three monthly injections of ranibizumab. One month after the third injection, the average improvement was a doubling of the visual angle.

"This was a substantial improvement. Higher doses led to faster recovery that lasted somewhat longer, but had no effect on improving vision," Campochiaro said.

It's long been suspected that the protein vascular endothelial growth factor (VEGF) plays a role in blood vessel leakage and macular edema. Since ranibizumab binds VEGF, the results of this study suggest that VEGF is a major contributor to retinal vein occlusion-induced macular edema, Campochiaro said.

The results of the three-month endpoint of the study were published in the April issue of Molecular Therapy. Information about continued treatment and follow-up of patients was expected to presented Thursday at the Association of Research in Vision and Ophthalmologyannual meeting, in Fort Lauderdale, Fla.

Two phase III trials of ranibizumab are currently under way. Both are funded in part by drug maker Genentech.

More information

For more on macular edema, visit The National Eye Institute.

But are some of the risks and complications of this elective surgery being lost in this laudatory celebration?

The U.S. Food and Drug Administration's Ophthalmic Devices Panel convened Friday to discuss post-LASIK quality-of-life issues. Its recommendation at day's end: That the FDA warn more clearly about the risks of the increasingly popular surgery, the Associated Press reported.

"This is ground-breaking. It's the first time anything like this has happened around refractory, or LASIK, eye surgery," said Dr. Christopher Starr, co-director of Cornea, Cataract and Refractive Surgery at New York-Presbyterian Hospital/Weill Cornell Medical College in New York City. "I think it's a good thing, because I know that the surgery, when done on the right patients, is a great, great surgery with phenomenally good outcomes."

According to the LASIK Study Task Force, formed in 2007, studies indicate a 95.4 percent satisfaction rate among patients worldwide. The Task Force consists of the FDA, the American Society of Cataract and Refractive Surgery, the American Academy of Ophthalmology, and the U.S. National Eye Institute.

But of the 7.6 million people who have undergone the procedure in the United States since the mid-1990s, 140 have written letters of complaint to the FDA.

Now the FDA has followed up on those complaints. Friday's hearing was part of a larger review to see if new warnings about LASIK surgery are needed to alert consumers to the possibility of eye pain, dry eyes, blurred or double vision, and other problems.

The FDA panel will also advise the full agency about how to conduct a $1.2 million study that the agency is planning with the National Eye Institute and the American Society of Cataract and Refractive Surgery to determine patients' quality of life after LASIK, the Washington Post reported.

On Friday, the FDA advisers recommended that the agency make clearer the warnings regarding LASIK surgery. The recommendations include: adding photographs to illustrate what people suffering certain side effects actually see, such as the glare that can make oncoming headlights a "starburst" of light; clarifying how often patients suffer certain side effects, such as dry eye; and making clearer the conditions that should disqualify someone from LASIK, such as large pupils or severe nearsightedness, the AP reported.

"The FDA has called this a quality-of-life issue, because patients are complaining that their vision isn't sharp, they have poor night vision, some have glare or halos, some complain that their eyes are dry," said Dr. Robert Cykiert, associate professor of ophthalmology at New York University Langone Medical Center.

Some of those disgruntled patients were on hand for Friday's FDA hearing.

"Too many Americans have been harmed by this procedure, and it's about time this message was heard," said David Shell of Washington, D.C., who had the surgery in 1998 and said he has "not experienced a moment of crisp, good quality vision since," the AP reported.

Colin Dorrian was a law school student from suburban Philadelphia when he was told he wasn't a good candidate for LASIK, but got the surgery anyway. His father, Gerald, detailed on Friday the six years of eye pain and blurred vision experienced by his son, before reading his child's suicide note: "I can't and won't continue facing this horror," the news service reported.

Matt Kotsovolos worked for the Duke Eye Center when he had a more sophisticated LASIK procedure in 2006, and said his doctors classified him as a success because he now has 20-20 vision -- something Kotsovolos called a deceptive industry practice, according to the AP.

"For the last two years, I have suffered debilitating and unremitting eye pain," Kotsovolos said. "Patients do not want to continue to exist as helpless victims with no voice."

LASIK (laser-assisted in situ keratomileusis) surgery involves cutting a small flap in the eye's cornea using a laser. With the flap held out of the way, the surgeon can then reshape the corneal tissue with another laser. The procedure can be used for nearsightedness (as in Tiger Woods' case), farsightedness and, in some cases, astigmatism.

But, the much-touted procedure is not for everyone. Those who should rule it out include individuals who have a misshapen cornea or excessively thin cornea, who have early cataract formation or big pupils, who have dry eyes, or underlying conditions such as lupus or rheumatoid arthritis, said Dr. Norman Saffra, director of ophthalmology at Maimonides Medical Center in New York City.

Negative results can include glare and halos around lights at night. Some patients have actually had to have corneal transplants when LASIK went wrong, Starr said.

Surgeons may also rule out patients with unrealistic expectations. "I had a patient who said, 'I want to be able to see a license plate on a dark country road from a mile away,' so I didn't do it," said Cykiert, who estimated that he declines about 20 percent of patients who come to him.

Cykiert recommends that the surgeon who is going to perform the LASIK surgery also be the one to pre-screen candidates. "One of the things [the FDA] is probably going to find is that some of the people who have complaints that are valid may possibly have not been evaluated pre-operatively as thoroughly as they could have been," he said.

"It's an elective surgery, you're operating on very healthy people, healthy eyes, you don't want to take any chances," said Starr, who turns away 50 percent to 60 percent of prospective patients who come to him.

Starr himself has declined to have the procedure, because he considers himself "borderline." (Refractive surgeons in general, however, are four times more likely than the general population to undergo LASIK, according to a survey from the American Society of Cataract and Refractive Surgery.)

But while screening is good, it can always be better.

"How can we identify that subset of patients whose lives are irreversibly changed from a relatively 'safe' procedure," said Saffra.

To that end, the new task force is undertaking a study to identify additional factors to help screen candidates for LASIK.

"This is a science in evolution, and it is unacceptable to any eye physician to do harm to a patient, to have people whose lives are changed negatively forever, when it should have been a slam dunk," Saffra said.

More information

The FDA has more on LASIK.

A team at the London School of Hygiene & Tropical Medicine's Trachoma Group said its findings challenge the World Health Organization's recommendation for annual antibiotic treatment and called for a re-evaluation of how communities affected with trachoma are treated.

The five-year study was conducted in Kahe Mpya, Tanzania. After an initial round of mass treatment (97.6 percent of residents) with single-dose azithromycin, the prevalence of trachoma decreased from 9.5 percent to 0.1 percent after two years.

A second round of mass treatment was carried out two years after the first round. Three years after the second round of mass treatment, trachoma DNA was not detected in the eyes of any of the 859 people who were checked, which suggested the infection had been eliminated.

A letter outlining the findings was published in the April 24 issue of the New England Journal of Medicine.

Currently, the WHO recommends three years of annual mass azithromycin treatment before reassessment in communities where 10 percent or more of children ages 1 to 9 have trachoma.

"Had WHO recommendations on antibiotic use been followed, three or possibly six annual rounds of mass treatment would have been offered in this community, whereas our data suggest that one round was sufficient," noted Dr. Anthony Solomon, lead author of the letter. "The less antibiotic we can use in each community, the more people we'll be able to use donated antibiotic for, and the lower the likelihood of the emergence of antibiotic-resistant strains."

More information

The MedlinePlus Medical Encyclopedia has more about trachoma.