Childhood Blindness and Pediatric Cataract

Worldwide, an estimated 1.5 million children are bilaterally blind. Most live in the developing world.1,2 The prevalence of blindness varies according to the socioeconomic development of the country and the mortality rate of those younger than 5 years of age. Ninety percent of the blind children in the world live in Asia or Africa, and 75% of all causes of childhood blindness in those areas are preventable or treatable.3

It has been estimated that 0.5 million children become blind each year, a rate of one new blind child every minute of every day.4 In developing countries, the rate of blindness can be as high as 1.5 per 1,000 people—10 times higher than in the industrialized world.1,3,5-8 For those who survive childhood, the burden of disability in terms of blind-years is huge. Indeed, the number of blind-years from childhood vision loss is almost equal to the number of blind-years caused by cataracts in adults. Irrespective of the cause, childhood blindness has far-reaching effects on the child and the family throughout life. It profoundly influences educational and employment opportunities as well as every aspect of the personal and social life of the family.

Accounting for 8% to 39% of all cases, cataract is one of the most treatable causes of blindness in children.9-26 Nearly 200,000 children are bilaterally blind from unoperated cataracts, complications of cataract surgery, or the presence of ocular anomalies associated with the cataracts. Early detection and intervention are recommended to reduce the disability for affected children and their families. In industrialized countries, the visual outcome of surgery for childhood cataract has improved as a result of earlier detection, advances in surgical technique and technology, and a better application of amblyopia management. In contrast, the outcome of pediatric cataract surgery in many developing countries remains poor as a result of late detection, inadequate surgical facilities for children, a lack of pediatric anesthesia, and inadequate follow-up.

In this article, we review the prevalence of childhood cataract and discuss ways to improve the outcome for affected children. As discussed herein, the burden of preventable cataract blindness can be lifted from the children of the world by implementing a combination of “best practices” for community-based detection and referral, regional surgery centers with technology specific to childhood cataract surgery, and trained teams of surgeons and anesthesia personnel who remain linked to their mentors.

PREVALENCE OF CHILDHOOD CATARACTs

The prevalence of childhood cataracts worldwide has been reported as one to 15/10,000 children. The wide range is because of the assortment of methods, the different age groups, and varying case definitions used in studies as well as true differences between populations.1 Foster et al1 estimated that the prevalence of congenital bilateral cataracts in industrialized countries is one to three per 10,000 children. The investigators calculated that approximately four children per 1 million total population per year will be born with bilateral cataracts in industrialized countries, and the figure for developing countries is likely to be 10 children per 1 million total population/year.

The prevalence of blindness from cataracts in children of developing countries is probably one to four per 10,000, compared with approximately less than one per 10,000 children in the industrialized world.1 Using a standardized classification and coding system, Gilbert et al27 evaluated 9,293 children examined in 40 countries and reported that the lens is responsible for 12% (range, 7% to 20%) of anatomical abnormalities in children.

CATARACT BLINDNESS IN CHILDREN
Control
Pediatric cataract-associated blindness can be avoided or treated using a combination of preventive services at the community level, specialized surgical services in pediatric ophthalmic units, and low-vision devices and services.

Primary Level of Care
Primary eye care includes services by trained community health workers. Their main responsibility is to prevent blindness from occurring. Personnel trained in primary eye care are essential for the control of blindness in children, as these providers can perform ophthalmoscopic screening of neonates and identify patients who need referrals. Patients needing referrals are those who require ophthalmologic assessment and treatment. The primary care providers also impart services for immunization, encourage long-term ocular follow-up, provide counseling to avoid consensual marriages between families with histories of childhood cataracts, and educate people to use preventive measures to avoid sports-related and other ocular trauma.

Secondary Level of Care
At the secondary level, the main responsibility is to maintain or improve functional visual outcomes. The eye care provider can carry out a full eye examination and assessment to make a provisional diagnosis, arrange surgery for the affected eye at the tertiary center, follow postoperative eyes to detect secondary opacities, work as a joining link between primary level of care and tertiary centers, effectively communicate with parents to ensure their involvement, and arrange screenings for children in their schools.

Tertiary Level of Care
Tertiary care services can include facilities for the trained ophthalmologist, optometrist, anesthetist, and pediatrician. They can provide surgical services within well-equipped centers containing vitrectomy instruments, ophthalmic viscosurgical devices, and high-quality IOLs. These providers can organize and provide low-vision services, responsibly participate in research, and train the faculty of primary and secondary level programs. Additionally, they support, supervise, motivate, and provide feedback to staff in secondary level centers, and provide long-term regular follow-up with assessment and treatment of posterior capsular opacification, glaucoma, refractive error, and amblyopia to achieve good visual outcomes.

PEDIATRIC CATARACT SURGERY IN THE DEVELOPING WORLD

The quality, accessibility, and affordability of pediatric cataract services must be carefully addressed to decrease the overall burden of visual disability in these patients. Although adult cataract surgery can be taken to the people, pediatric cataract surgery is better performed in regional centers where general anesthesia is practiced and the surgeons perform childhood surgery often. Eye camp staff can assist with the identification and transportation of the children blinded by cataract to the regional centers.

Of significant influence in persuading parents to allow their child to undergo cataract surgery is often the example of other children in the community whose sight was restored by such an operation. This effect is especially strong when there are significant transportation costs and lost wages associated with getting the child to the regional center. A reputation for good results from the surgery is essential. Thus, especially in the initial phase, patient selection is very important. Children with good visual potential (bilateral dense cataracts without nystagmus or microphthalmia) should be treated first to ensure that parents and community leaders will trust in and advocate the surgery being offered to the blind children.

In addition to equipment for manual cataract surgery and high-quality, affordable IOLs, machines for automated vitrectomy should be available in all regional centers set up for childhood cataract surgery.2 These machines need reusable tubing and should receive regular maintenance from trained biomedical technicians. Many such machines are rugged enough to withstand the rigors of frequent use in developing world settings.

CONCLUSION

For most of the nearly 200,000 children blind from cataracts, a life of sight is still possible. Increased capacity for pediatric cataract surgery and care are needed in many areas. In other regions, the facilities and surgical teams are in place but are underutilized, due to a lack of knowledge, monetary constraints, or a negative perception of the surgery owing to poor results from inadequate or poorly timed treatment. Insufficient ophthalmic and anesthesia staff, a lack of surgical instruments, and poor equipment maintenance are also widespread in the developing world. It can also be logistically complex to identify the children who will benefit the most from surgery and reliably transport them to a treatment center.

In addition to the many ongoing efforts aimed at reducing the number of pediatric cataracts through rubella vaccination and improvements in nutrition, the following steps will help. First, communities need to do a better job of identifying and referring children with cataract early. “Best practices” need to be identified, codified, and implemented worldwide. Second, regional centers for the surgical treatment of pediatric cataract must be designated and properly equipped and staffed. Biomedical repair expertise must not be left out, as it is as important as the equipment itself. The doctors and medical staff should receive appropriate hands-on training (Figure 1). Third, a sustainable partnership known as a twinning relationship should be established between each regional, developing world, pediatric cataract center, and an industrialized world center that has experience with pediatric cataract surgery. A memorandum of understanding that clearly states the roles and responsibilities of each center should govern this partnership. Periodic visits, ongoing electronic consultation, and assistance with supply lines and equipment when needed are among the responsibilities of the twinning relationship in the industrialized world. These steps can lift the burden of avoidable blindness from childhood cataract throughout the world. Because of the number of blind-years prevented with each surgery, pediatric cataract treatment can be among the most cost-effective intervention in all of ophthalmology. 

M. Edward Wilson, Jr, MD, is Pierre G. Jenkins Professor and Chairman, Department of Ophthalmology and Director of the Storm Eye Institute, Medical University of South Carolina in Charleston. Dr. Wilson may be reached at (843) 792-7622; wilsonme@musc.edu.
Rupal H. Trivedi, MD, MSCR, is Assistant Professor of Ophthalmology at Storm Eye Institute, Medical University of South Carolina in Charleston. Dr. Trivedi can be reached at (843) 792-6301;
trivedi@musc.edu.

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