In every corner of the world, eye care professionals and public health workers are tackling cataracts, managing retinopathies and glaucomas, and treating trauma and infections. But looming over these little miracles are clouds of poverty, dislocation and a paucity of ophthalmologists.
Apart from armed conflict or widespread famine, few social or economic tragedies can impair entire societies as profoundly as preventable blindness. “Visual impairment is a major cause and consequence of unnecessary human suffering, often leading to poverty, unemployment, ill health, social exclusion and early death,” according to the International Agency for the Prevention of Blindness. The agency estimates that the annual global impact of blindness and low vision is nearly $42 billion. As large as that number is, it cannot account for the tremendous moral crises and emotional losses involved: Approximately 60 percent of children in low-income countries die within one year of becoming blind, and 90 percent of visually impaired children in those countries are deprived of schooling.1
The World Health Organization has compiled even more dramatic numbers:2
- Around the world, more than 161 million people are significantly visually impaired and, of these, 124 million have low vision and 37 million are blind.
- Another 153 million people live with uncorrected refractive errors, and nearly all of these could recover normal acuity with corrective lenses.
- The least economically developed communities endure the highest prevalence of visual impairment: More than 90 percent of all visually impaired people live in low- and middle-income countries.
- Except in the most developed countries, cataract remains the leading cause of blindness, and yet cataract surgery is one of the most cost-effective treatments in all of medicine, allowing people to increase their economic productivity by up to 1,500 percent of the cost of surgery in the first postoperative year.
- The reason to dwell on these statistics? Up to 75 percent of all blindness in adults and 50 percent of childhood blindness is avoidable through prevention or treatment.
A Worldwide Campaign
The problems of blinding disease and visual impairment are so internationally pervasive that only an international effort will have a significant impact for the better. WHO has already formulated a clear mission to that end: “The objective of WHO’s prevention of blindness team is to assist Member States to effectively prevent blindness and restore sight, when possible. The global target is to ultimately reduce blindness prevalence to less than 0.5 percent in all countries, or less than 1 percent in any country.”3
Even more ambitiously, almost 10 years ago WHO launched the Global Initiative for the Elimination of Avoidable Blindness, or “Vision 2020: The Right to Sight,” an international campaign to abolish unnecessary blindness across the globe. The specific goals are eliminating avoidable blindness by 2020 and thwarting the projected doubling of avoidable visual impairment between 1990 and 2020.
Visible achievement. Already, significant headway against many eye diseases is apparent. Infectious causes of blindness, such as trachoma, have been successfully controlled in Morocco, Mexico and Oman, while dozens of other countries are making inroads. In fact, trachoma, vitamin A deficiency and onchocerciasis, which caused 15 percent of all cases of avoidable blindness in 1996, cause just 3.7 percent of all cases today, according to WHO estimates. Blinding trachoma alone has decreased to about 80 million affected people from 360 million people in 1985.
“Although many countries still have trachoma, what’s wonderful is that 42 countries are reporting progress in fighting this disease,” said Hugh R. Taylor, MD, professor of ophthalmology and indigenous eye health at the University of Melbourne in Australia. From 1977 through 1990, Dr. Taylor held a joint appointment in international health and epidemiology at Johns Hopkins University.
The accomplishments of international public health workers are a badge of honor. But their efforts are met with daily frustrations. Following are some of the major issues facing eye medicine around the world.
Serving the Victims of Violence
A population on the move or living in temporary shelters is difficult to monitor and care for. Today that includes millions of refugees who have fled headline wars in Sudan, Afghanistan, Iraq, Georgia and the Palestinian territories. In addition, the Central Intelligence Agency’s 2008 World Factbook lists more than 80 other countries, including the United States, coping with refugees or internally displaced persons (IDPs) within their borders. The total numbers are staggering, and, in fact, on its Web site, the CIA offers an estimate of the world’s refugees that exceeds even the U.N.’s estimates: “The United Nations High Commissioner for Refugees estimated that in December 2006 there was a global population of 8.8 million registered refugees and as many as 24.5 million IDPs in more than 50 countries; the actual global population of refugees is probably closer to 10 million, given the estimated 1.5 million Iraqi refugees displaced throughout the Middle East.”4
Eyes at the mercy of others. Not only is the task of providing eye care logistically difficult among displaced people, but governments of states with sizable refugee populations must have the will and skill to deal with the pressing need. “We can advise countries about providing eye care services, but in the end delivering the services is up to the states,” said Ivo Kocur, MD, team leader of Prevention of Blindness and Deafness for WHO in Geneva. “And when there are staff shortages in many areas of health care, providing preventive eye care or ophthalmology treatment to refugee populations becomes quite difficult.”
Conquering Infectious Disease
Onchocerciasis. Intensive efforts by WHO to control onchocerciasis have been highly effective in West Africa, eliminating the disease as a public health problem in countries such as Niger and Senegal. Since the launch of the WHO’s onchocerciasis control program in 1995, which included larvicide spraying of blackfly breeding sites as well as the delivery of the microfilaricide ivermectin—donated by Merck—to communities where the disease is endemic, 40 million people in 16 countries have been treated annually, and 600,000 cases of blindness from the disease have been prevented, according to WHO.
Trachoma: Use drugs. The political and financial support for eliminating trachoma has also risen significantly. Azithromycin is reaching many more communities, and researchers have hypothesized that treating a community with single-dose azithromycin might help eradicate the disease, according to Sheila W. West, PhD, professor of ophthalmology at Wilmer Eye Institute.
Surgery combined with azithromycin also has been effective in treating trichiasis, an end-stage condition of blinding trachoma. In a study Dr. West and colleagues published in the Archives of Ophthalmology in 2006, single-dose azithromycin following surgery reduced recurrence of trichiasis by 30 percent, compared with topical tetracycline.5
Trachoma: Use deputy surgeons. Efforts also are under way to train more eye care nurses and medical assistants to perform surgery for trichiasis in countries that do not have enough eye surgeons, according to Dr. West. The health worker anesthetizes the eye, positions a retractor and creates an incision along the lid margins and tarsal conjunctiva. The side of the lid with lashes is turned outward and the two sides are stitched together. This simple procedure prevents lashes scraping the cornea.
In fact, Dr. West and colleagues have created a manual on certifying surgeons for trichiasis surgery—to make sure their skill set is optimal. The manual has been published by WHO and is now in use in Tanzania and Niger; it is starting to be used in 22 other countries. “In the setting of emerging countries where trachoma is a public health problem, it’s necessary for trichiasis surgery to be skill-driven rather than degree-driven,” Dr. West said. In developed countries, of course, with less dire situations, any eye surgery would come under the purview of a trained MD.
Trachoma: Use washcloths. Most important, perhaps, the “SAFE” strategy for eliminating the disease has increased. SAFE stands for surgery, antibiotics, facial cleanliness and environmental change, and it’s part of the multifaceted promotion needed to control trachoma, said Dr. West.
In countries such as Ethiopia and Tanzania, community health efforts have emphasized the importance of hygiene with posters, T-shirts and radio ads, according to Dr. Taylor. “In our public education efforts, we emphasize that having a dirty face can lead to eye infection. And repeated reinfection means scarring and blindness.”
To eradicate trachoma-related blindness by 2020, WHO is targeting affected regions with health education campaigns, free distribution of azithromycin with donations from Pfizer, the distribution of $100 surgical kits in needy communities, the building of latrines, and integrating SAFE into primary health care and sanitation. “One reason why trachoma has not been eliminated is the lack of clean water and support for changing water-use patterns in resource-poor areas,” Dr. West said. “Many emerging countries still face huge problems in providing these services.”
When Easy Care Isn’t So Easy
Preventable cataract. The large number of smokers in middle-income countries also contributes to avoidable cases of blindness. Up to 25 percent of cataracts worldwide could be prevented by not smoking, according to Dr. West. “There does not seem to be as much social awareness of the dangers of smoking in emerging countries as there is in the U.S. and Europe. And the marketing messages of the tobacco companies are insidious and ever-present in emerging countries, where there’s less regulation,” Dr. West said.
Once a smoker acquires a habit—particularly if they start smoking in adolescence—it becomes very difficult to quit, she said, especially in the face of marketing. For smoking cessation efforts to succeed, the governments of emerging countries will need to start regulating advertising, and private and public enterprises need to contribute by banning smoking in public places. Private and public efforts need to be made to send the message that smoking is not socially desirable, Dr. West said.
Treatable cataract. Where cataract should not be a lingering problem, scarce resources make it so anyway. “The devotion of the ophthalmologists in Latin America is impressive,” said J. Bronwyn Bateman, MD, a geneticist and professor of ophthalmology at the University of Colorado in Denver who has conducted extensive multigenerational research on childhood cataract in Latin America. “But they do not always have the funds to perform procedures such as cataract surgeries with state-of-the-art instruments, or even have the resources or the industry support to attend medical meetings to keep abreast of advances in the field.”
Glaucoma. The treatment of glaucoma, the second major cause of blindness in the emerging world, poses a practicality problem. Patients who receive eyedrops need to be monitored regularly, and that can be a problem where eye care is not routinely accessible. “In emerging countries, expertise in treating glaucoma is very low,” said Harry A. Quigley, MD, professor of ophthalmology and director of the glaucoma service at the Wilmer Eye Institute. There is also a higher incidence of consanguineous marriage in many emerging countries—leading to a higher rate of recessive forms of glaucoma that have an early onset, Dr. Quigley noted. He said that scientists are working on innovative ways to monitor glaucoma patients, as well as to screen for glaucoma and other eye diseases. “One of our goals is to screen for all eye diseases with one instrument—an advance that will greatly simplify identification of potential causes of blindness. And we think that will occur in the next five to 10 years.”
Refractive errors. Another concern in emerging countries is uncorrected refractive errors. There are estimated to be 153 million people with visual impairment resulting from uncorrected refractive errors, according to WHO. Globally, uncorrected refractive errors are the main cause of visual impairment in children aged 5 to 15.6 The prevalence of myopia is increasing dramatically among children, particularly in urban areas of Southeast Asia. Many countries simply don’t have the resources for screening for refractive errors or the economic means for providing glasses, according to Dr. Bateman, and the lack of reading glasses can handicap adults seeking jobs, she said.
|India Offers a Model of Care |
Access to eye care has improved greatly in certain communities of India with the establishment of regional eye care centers by the L V Prasad Eye Institute in Hyderabad, an eye hospital, research and training institution.
The institute has created a pyramidal structure of regional eye clinics in the Indian state of Andhra Pradesh and has established at least one vision clinic for every 50,000 people there, each staffed by a trained technician. At each clinic, primary eye care and services for refractive errors are available even to those living in remote locations. For an initial capital investment of $10,000, these clinics are newly built or upgraded versions of existing facilities. Each is staffed by a high school graduate, trained to be a vision technician, selected from the local community.
A simple system yields results. “In our clinics, people can be screened for potentially blinding diseases and refraction diagnoses,” said Gullapalli N. Rao, MD, chairman of the Hyderabad Eye Institute and founder of the L V Prasad Eye Institute. “They’re linked to rural eye hospitals with staffs of up to 35 people. But we’ve found that just providing primary care at the regional level has made a real difference in eye care in India. Sixty-five percent of patients who visit our community vision clinics don’t need to get referred to the next level,” Dr. Rao said.
As well as screening for glaucoma and cataracts, the L V Prasad ophthalmology technicians also can screen for diabetic retinopathy. India has the highest prevalence of diabetes in the world, and Dr. Rao anticipates that diabetic retinopathy will take up more resources in the coming years. “We’ve taken a real public health approach to diagnosing eye disease,” he said.
Care, yes, but also research. The institute is strongly committed to research, including efforts using stem cells to treat blindness surgically. Virender S. Sangwan, MD, head of the cornea and anterior segment, ocular immunology and uveitis services of the institute, has perfected a corneal regeneration procedure for patients with damaged corneas. The scientists at L V Prasad use stem cells harvested from the limbus of the patient’s good eye, or from a close relative, to repair the cornea. Placed in a petri dish, the adult stem cells are chemically induced to replicate, becoming the epithelial tissue. The epithelium is then transplanted into the eye of the patient, where in most cases it takes hold and develops. In 56 percent of cases at the L V Prasad Institute, patients can see clearly 40 minutes after surgery is completed.
And those patients are peering, hopefully, through new windows on the future.
The Problems of Poverty (and Wealth)
As some emerging nations become fully developed societies, the perennial ogres of infection and cataract will be replaced by the problems more associated with longevity and prosperity: diabetic retinopathy, retinopathy of prematurity, glaucoma and age-related macular degeneration. Even now, these are not insignificant fractions of the world’s visual impairment. In 2002, AMD was responsible for 9 percent, and glaucoma 12 percent, of disease-related blindness in the world.7 Unfortunately, if the established industrial countries are predictive of future trends, skilled eye surgeons and resources for ophthalmic medical care may not be able to keep up with demand.
The future: ominous or optimistic? As the world stands now, the weary divide between haves and have-nots is still in place. The quality of eye care that is standard in North America, Europe, Australia and Japan is not consistently available in emerging nations—largely because of inadequate numbers of local ophthalmologists, an absence of funding to buy the latest pharmacologics and surgical instruments, and barriers to access, such as transportation problems for people who live in remote locations. “In developed and economically advanced countries, there are many services to deal with these eye conditions. But in poorer communities, services may not be available for those who need them,” said Dr. Kocur.
In some countries in Africa, he added, the dearth of eye care professionals is so dramatic that there is only one ophthalmologist for more than a million people.
“Some emerging countries are saddled with poor economies that make it very difficult to create eye health programs that work,” said Dr. Bateman. “The challenges faced by ophthalmologists in Latin America are enormous. There’s a lack of a medical infrastructure to facilitate access to eye care along with a need for more advanced eye care technology. And in some countries, ophthalmologists simply cannot make a living. Either there isn’t enough publicly funded eye health care or there aren’t enough people who can afford to pay for quality medical services. So many ophthalmologists end up leaving medicine.”
And that is an international problem that warrants an international discussion.
1 Faal, H. and C. Gilbert. Community Eye Health
5 West, S. A. et al. Arch Ophthalmol
|MEET THE EXPERTS |
J. BRONWYN BATEMAN, MD
Geneticist and professor of ophthalmology at the University of Colorado in Denver.
IVO KOCUR, MD
Team leader, Prevention of Blindness and Deafness for the World Health Organization in Geneva.
HARRY A. QUIGLEY, MD
Professor of ophthalmology and director of both the glaucoma service and the Dana Center for Preventive Ophthalmology at Wilmer Eye Institute in Baltimore.
GULLAPALLI N. RAO, MD
Chairman of the Hyderabad Eye Institute and founder of the L V Prasad Eye Institute in India.
HUGH R. TAYLOR, MD
Professor of ophthalmology and of indigenous eye health, Melbourne School of Population Health, University of Melbourne.
SHEILA W. WEST, PHD
Professor of preventive ophthalmology at the Dana Center for Preventive Ophthalmology, Wilmer Eye Institute in Baltimore.