The burden of glaucoma in Africa represents a perfect storm of high prevalence and limited resources. There are an estimated 8 million people with open-angle glaucoma in Africa, and this number will double by 2040.¹ Vision loss and blindness from glaucoma occur in Africa at twice the average global rate.² The sub-Saharan region of Africa (SSA) lacks the economic and human resources to address this burden — SSA is home to the world’s 10 poorest nations and has the fewest number of doctors per capita of any other global region, according to the World Health Organization.

There are many barriers to preventing glaucoma-related vision loss and blindness. Often, patients present with late-stage disease because of a pervasive low level of awareness and lack of knowledge about glaucoma and its most serious implications, including the risk of vision loss and blindness.

More than 90% of persons with glaucoma don’t know they have it,³ and screening for glaucoma has been largely unfruitful, owing, in part, to significant overlap in the appearance of healthy and glaucomatous optic nerves, particularly in black patients who have larger optic nerves and cups than their Caucasian counterparts.^4,5

Suboptimal Treatment Options

Once diagnosed, treatment is often suboptimal for a variety of reasons. Adult literacy is low throughout Africa (62%),⁶ and nearly half (47%) of the population lives on less than $1.90 USD a day.⁷ The cost of glaucoma care becomes a burden to the family, perpetuating the cycle of poverty.

Access to care is also a problem. Most eyecare workers are concentrated in the large cities. There are very few working in resource-deprived facilities, and these typically lack a clear public health control strategy and high-quality integrated glaucoma care.

The majority of the population living in rural areas have no access to health facilities at all or must depend on inadequately equipped facilities. Long-distance trips prevent many from receiving care, complying with treatments, and returning for follow up.

Among those who do have access to providers, additional barriers prevent effective glaucoma management. The cost of medical treatment is high and often not sustainable by a majority of patients. Surgery is not widely accepted, partly because of high initial cost and/or a fear of going blind from the surgery. Also, the volume of glaucoma surgery varies widely among ophthalmologists in Africa, and so do surgical outcomes.

The Role of SLT

Solving Africa’s glaucoma problem will not be easy. Medical therapy — the mainstay of treatment in developed regions — is impractical in most poor African countries, where the cost of medications may exceed the average annual per capita income. Likewise, surgical interventions are limited by cost, a paucity of surgeons trained to perform glaucoma procedures, and high refusal rates by patients.

Recently, attention has turned to the role of laser therapy — specifically selective laser trabeculoplasty (SLT) — as part of the solution to Africa’s glaucoma burden. A preliminary prospective study of SLT in an Afro-Caribbean population in St. Lucia demonstrated mean IOP reductions on the order of 30% to 40% with no adjunctive medical therapy at 12 months.⁸ A more robust prospective study evaluated SLT in glaucoma patients from both St. Lucia and Dominica and found mean IOP reductions at 12 months of ~30% with success rates of ~80% (IOP reduced at least 20% from untreated baseline on no medications) at 12 months after a single treatment session.⁹ Additionally, a retrospective study of SLT in black Africans demonstrated mean IOP reductions on the order of 40% with ~90% response rate at 12 months.¹⁰

Taken together, these studies suggest that SLT lowers IOP 30% to 40% in people of African descent, with initial response rates in the range of 80% to 90%. Importantly, SLT is very safe — no serious vision-threatening complications were reported in any of these studies, and complications following SLT are rare throughout the world.¹¹ In this population with a high disease burden, SLT offers efficacy consistent with incisional surgery and safety rivaling medical therapy.

In addition, SLT has many attributes that favor its use in Africa. It is noninvasive, easy to learn and perform, requires no postoperative anti-inflammatory^12,13 or anti-microbial therapy, is portable, and is cost-effective relative to medical therapy.^14,15 Once the equipment and expertise are on site, the incremental cost of each SLT treatment is limited to the costs of electricity, lens coupling gel, and equipment maintenance. Equally important, SLT can be safely repeated and provides comparable efficacy to initial SLT.^16-22

Helping Hands

The enormous task of reducing glaucoma blindness in Africa will require a coordinated effort by many people with a multitude of skills. To this end, the African Glaucoma Consortium was founded in 2017 specifically for this purpose. The Consortium is a collective of African ophthalmologists, clinical scientists, and program builders working together to identify and develop the necessary resources for a successful continent-wide glaucoma care program.

The group’s long-term goal is to develop an integrated network of glaucoma centers of excellence throughout Africa. These centers will provide tertiary glaucoma care — including both laser and incisional surgery — in partnership with local and regional primary and secondary care partners, offer training to young surgeons to expand capacity, and conduct impactful research to clarify optimal care processes for glaucoma in this region.

Also ongoing is the Human Heredity and Health in Africa (H3Africa) initiative. Funded by the NIH in partnership with Wellcome Trust and with guidance from the African Society of Human Genetics, this program is designed to provide African scientists with new opportunities to lead research into the genetics and environmental contributors to health and disease issues of importance to Africa. In this study, the researchers will address multiple aspects of African glaucoma — from improving diagnosis to novel treatment strategies — all of which are integrated with state of the art gene discovery.

Working Together

In summary, novel research and collaborative initiatives are inspiring innovative solutions to Africa’s glaucoma burden. Efforts are under way to address issues ranging from population screening to optimizing care processes to exploring the genetic basis of glaucoma. Some goals include helping to improve the skill sets of the existing healthcare providers and the recruitment and training of new providers to expand regional capacity for care delivery.

Working together to understand the barriers to care and develop strategies to surmount these obstacles, we will build a glaucoma care program capable of providing high-level, evidence-based clinical care to the millions of Africans with glaucoma. GP

References

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Dr. Realini is professor of ophthalmology at the West Virginia University Eye Institute. His clinical practice and research efforts are focused on improving the lives of and preventing blindness in patients with glaucoma.

Dr. Ashaye is head of the department of ophthalmology in the College of Medicine at the University of Ibadan. She is the principal investigator for Eyes of Africa: The genetics of blindness, an H3Africa project funded by the NIH and Wellcome Trust.