Comparative study on preventing avoidable blindness in China and in Nepal

“Vision 2020: The Right to Sight” is a worldwide, concerted effort to eliminate avoidable blindness by 2020. It will enable achievement of the common goal of eliminating preventable and treatable blindness. Over the 6 years since launching the global campaign, much attention from the Chinese government has been drawn to preventing avoidable blindness. International society has given a lot of support.¹ Annual cataract surgical output in China is increasing from year to year, but the current levels of cataract surgery are still far below the numbers required to clear the existing backlog.^2-4

It has been well documented in China that the cataract surgical ontput is low and the outcome of the cataract surgeries is disappointing;^1,5-7 but no report on why the situation is unacceptable. Nepal is one of the underdeveloped countries in the world, but one of the advanced countries in combating avoidable blindness. This paper notes the progress towards the “Vision 2020” target and explores the reasons by comparative study to the situation in Nepal and in China.

Literature review
The available data published in books, official documents and journals as listed in the reference were reviewed. The review focused on demographic data, main causes of blindness, human resource, infrastructure and service delivery as well as cataract surgical output and outcome.

Field visit
The visit to National Society for Comprehensive Eye Care in Nepal and eye care institutions in Kathmandu, Lumbini, Tensen and Pokhara in Nepal from April 30 to May 7, 2005 was supported by Seva Foundation (USA). Thirty-one eye care professionals and consumers were interviewed.

Follow-up communications
Follow-up communications via internet to verify some data and request for additional data were conducted within one month after the field visit.

Statistical analysis
All statistical analyses were carried out with SPSS Version 11.5. The chi-square test was used for comparisons involving categorical variables. P<0.05 was considered statistically significant.

RESULTS

Cataract backlog, magnitude and main causes of blindness
Based upon the national sampling survey of the disabled in 1987 and the epidemiological survey in late 1980s, the rate of bilateral blindness in China was 0.43%-0.45% nationwide,^1,8 lower than that in Nepal (P<0.05). Based on these data, at least 5 million people suffered from bilateral blindness in China, so approximately 18% of the world's blindness is in China. Cataract blindness accounts for 50% and 78% of the blindness in China and in Nepal respectively.^2,8,9 Due to a larger population size, the cataract backlog in China is about 30 times higher than that in Nepal (Table 1).^9,10 Moreover along with population ageing, the cataract backlog in Nepal may have reached 174 250 based upon the newly estimated data.

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Table 1. Population, blindness rate and cataract backlog

In addition to the bilateral blindness, the rate of unilateral blindness in Nepal is 1.7%.⁹ There is a considerable number of unilateral cataract blindness in China too. According to WHO calculation, an average of 3.4 (2.4- 5.5) people have low vision for each blind person.¹¹ Therefore, the total number of people with low vision in China is probably at least 17.0 million.

Human resources and cataract surgical output
Derived from Table 2, the ratio of ophthalmologist to population in China is 1:55 000; but the figure in Nepal is 1:200 000.^9,12 The available data suggests that during the past 8 years there has been an increase in the number of cataract surgeries being performed both in Nepal and in China.^9,13,14

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Table 2. Human resource and cataract surgical output

The cataract surgical rate (CSR, total number of cataract operations performed within a year per one million inhabitants) may vary between provinces in China, such as 1197 in Beijing, 1548 in Shanghai, 953 in Tibet, 608 in Qinghai; but only 196 in Guizhou, 216 in Chongqing.

Infrastructure development and service coverage
Nepal is administratively divided into 5 development regions, 14 zones and 75 districts. The population in each zone varied from 2 million to 5 million. There are 16 well equipped eye hospitals (eye centers) and 28 primary eye care centers. The service network has covered all districts.^9,15,16 Eye care service is weak in general hospitals.

The situation in China is quite different. The common types of eye care providers are Department of Ophthalmology and Department of Five-sense Organs in general hospitals.¹⁷ There are 72 eye hospitals; however, most of them are in larger cities. The service has only covered part of the areas. A national survey of eye care resources in 1997 reported that only 49.1% of hospitals at the county level have Department of Ophthalmology or Department of Five-sense Organs.^17,18

Cataract surgical coverage is defined as the ratio of people who have had a cataract operation among the people with cataract vision less than 6/60.

The number of cataract surgeries and cataract surgical coverage in Nepal and in China from 2001 to 2004 is shown in Table 3.

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Table 3. The number of cataract operations and cataract surgical coverage in Nepal and in China^9,14

Cost of cataract surgery
The cataract operation is free of charge in any eye cap in Nepal.^9,16,18,19 The cost of cataract surgery in hospitals is from 1 700 to 2 100 NC (US $22－28) per eye. The most common cost of the same operation in China is 2500- 8000 RMB Yuan (US $312－999) per eye.

Outcome of cataract surgery
Based on the report by China Disabled Person's Federation (CDPF), immediate outcome of the cataract operations performed during the past 10 years showed 97.0%-98.1% of the operated patients had a visual acuity equal or better than 0.05 for the best corrected vision.^13,14

However, population-based studies have demonstrated poor outcome (Table 4). There were two cross sectional surveys to evaluate the operated patients at Shunyi County of Beijing and Doumen County of Guangdong in 1996 and in 1997 respectively.^5,6 In 2000, another cross sectional study in Tibet (Tibet Eye Care Assessment, TECA) investigated the cataract patients operated on from the past 10 years to the past one month.⁷ The study was jointly conducted by the Seva Foundation, Tibetan Health Bureau and Tibet Development Funds.

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Table 4. Cataract surgical outcome (presenting vision of the eyes after operation) in China and in Nepal

DISCUSSION

China is a country with great differences between provinces and prefectures in the rate of blindness; 0.43% in Shanghai city, 0.57% in Yunnan province, 0.40% in Sichuan province, 0.56% in Shunyi County and 0.12% in Ninghe County.²¹ In some areas, the rate of blindness is 2 or 3 times higher than the national average, i.e. equal or even higher than that in Nepal. One of the examples is Tibet; the rate of blindness is over 1.00%.^22,23 For Tibetans aged 40 years and over, prevalence of cataract is 11.8%.²² However, attention should be drawn to CSR. In some poor provinces, such as Tibet and Qinghai, CSR is higher than other poor provinces due to intensive programme of blindness prevention.

Up to 80% of blindness in China can be prevented or treated, with cataract continuing to be the major cause of blindness.^1,2,24 According to WHO estimate, the annual incidence of blindness in China is 450 000, 400 000 of them are due to cataract.¹ This means that one person becomes blind every minute. During the past 17 years, 5.50 million cataract operations were performed.^12,13 The remaining backlog is calculated as: 2.5 million + (400 000/year×17 years)-5.50 million = 3.80 million.

It is noted that the annual average output in China has increased only in recent years and is still far from meeting the need.^1,3,11 In 1994, the number of annual cataract operation was about 140 000; the CSR was only 136.³ If the current level remains unchanged, it will need at least 7 years just to clear the existing backlog.

One of the important aspects is efficiency. In Nepal, one ophthalmologist performs 1438 cataract operations on average during one year; but the figure in China is 24.^9,14 The Shree Rana Ambika Shah Eye Hospital in Lumbini, Nepal has 11 ophthalmologists;²⁵ the annual cataract surgical output is 26 269. Despite the lower baseline of cataract surgical output in China, the improvement is much slower than that in Nepal. From 1996 to 2004, the CSR in Nepal rose 3.18 times; but only 2.28 times (P<0.01) in China in the same period.^3,7,9 Unfortunately, the CSR in Nepal would have achieved 5 870 if all the patients were Nepalese. Currently, about 73% of the cataract patients are from India due to better eye care services in Nepal.

Cataract surgical coverage reflects the number of treatment services available, access to those services and utilization of those services by the population. Theoretically, precious cataract surgical coverage should be derived from the number of cataract surgeries at certain point of time and the cataract blindness at the same point of time. Unfortunately, it is very hard to match these components and know how many people, blind from cataract, die each year. Therefore, the number in Table 3 may only serve a rough cataract surgical coverage. The increasing number of ophthalmologists and surgical services are not adequate to improve the cataract surgical coverage. Moreover, community-based efforts are needed to identify, educate and encourage people (in particular women and the disabled) to accept the surgery.

Cataract surgical outcome is a key indicator to reflect the quality. There is lack of nationwide, reliable epidemiological data on overall quality of the surgeries. The outcome report by CDPF does not come from an epidemiological survey and may only represent immediate outcome of the recent operations. However, the findings in Table 4 represent surgeries done recently and done a long time ago. There is no information on pre-operative vision or surgical complications that cause the poor vision. Moreover, the findings represent the presenting vision, not the best corrected.

There are significant differences on the cataract surgical output or CSR between Nepal and China. There are barriers to achieve larger volume cataract surgery in China:

Cost of the surgery
The annual income of farmers in China is about 1.5-4 times higher than that in Nepal, but the cost of cataract operation per eye in China is about 14-23 times higher than that in Nepal. Most of the farmers in rural China have to pay their medical cost by themselves. However, the average annual income of the poor farmers in China is less than 2000 RMB Yuan. Thus, the surgical cost is 2-3 times their annual income. Not surprisingly they can not afford the service.

Qualified cataract surgeons
What is an ophthalmologist? The definition is different in China and in Nepal. The ophthalmologist in Nepal means that the faculty student graduated from a recognized university and has completed the residence training in ophthalmology; but in China the ophthalmologist means the same student on or after the residence training. Some ophthalmologists at county level only graduate from middle level health school. Not surprisingly, the skill of a considerable number of ophthalmologists in China is very weak.

The national survey of eye care resources revealed that only 28.74% of the ophthalmologists nationwide graduated from a recognized university; 53.81% have the expertise to perform cataract operation.^17,18 In county hospitals, lack of qualified cataract surgeons is even more pronounced.

Surgical equipment and instrument in county hospitals
The lack of facilities, equipment and supplies for eye care at the county level is a significant obstacle to extending cataract services to the rural population. The data from the national survey for eye care resources showed that only 39%-42% of the county hospitals have an ophthalmoscope, 57%-63% a slit lamp, 19%-36% an operational microscope, 59%-63% a tonometer, 54%-58% trial lens sets, and 27%-40% a perimeter microscope.^17,18

Distance to access the service
Most of the cataract patients live in rural areas. The distance from a village to the county town is ranging between 15 to 300 kilometers. Also the transportation is poorly connected to some villages. If the service is not available at county level, the patient has to travel even further to prefecture or city to access the service. Obviously, it is a great obstacle to the poor patients.

From 2000 to 2020, population aged 60 years or over in China will increase by 90%.²⁶ The incidence of age-related cataract may increase. China is on the stage of “epidemiological transition” with rapid population ageing. As 18% of world's blindness is in China, if China can not achieve the target of “Vision 2020: The Right to Sight”, it will have much negative impact on the progress of preventing avoidable blindness in the world. Further attention is needed to address this issue.

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