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Lessons from the Togo Glaucoma Project
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SLT shows promise as treatment for millions of Africans with glaucoma.
Prof Shlomo Melamed participates in the training event at the Regional Hospital Center of Lomé Commune, Togo. (Images courtesy of Lumenis)
In Africa, glaucoma presents a uniquely difficult problem, as its high prevalence is compounded by economic barriers to essential medical care. Selective laser trabeculoplasty (SLT) is a potentially transformative modality in this setting, presenting an opportunity for quick, safe, and effective long-term treatment.
During a trip to Togo, West Africa, my colleagues and I taught local ophthalmologists to perform SLT in a model that we hope to see replicated throughout the region.
Glaucoma’s impact in Africa
Primary open angle glaucoma (POAG) is highly prevalent in Africa, causing 15% of the blindness in the continent.1 Results of a large study in urban West Africa showed that the condition affects 6.8% of the population,2 and this is believed to be due to a higher inherited risk as evidenced by a higher prevalence of glaucoma among people of African descent around the world.3
In addition, the disease in this population is often severe and progresses rapidly to damage the optic nerve and visual fields.4 Consequently, it is not unusual for many family members to be affected by glaucoma, including some with total bilateral blindness.4 The devastating effect on families presents a public health problem and a significant economic burden.4
(Images courtesy of Lumenis)
Africans’ elevated genetic risk for high-tension glaucoma makes screening essential and management imperative. Unfortunately, many people face limited access to basic care and effective treatments. In West Africa, where my work has focused, people are severely impoverished, with 36.8% of the population living in extreme poverty (less than $1.90 a day).5 This affects access to care in myriad ways:
Countries have a shortage of ophthalmologists and ophthalmic caretakers, with just 2.5 ophthalmologists per million people in sub-Saharan Africa.6 There is also a chronic shortage of modern medical equipment for diagnosis and treatment7 and an unstable supply of glaucoma medications.8
Ophthalmologists lack expertise in trabeculectomy and minimally invasive glaucoma surgeries.9
For many patients, the cost of chronic medication is too high and the inefficient transportation system prohibitive.
Thus, glaucoma patients in West Africa rarely receive the early diagnosis required to prevent severe visual loss. More often, they go undiagnosed or are diagnosed at a late stage and then undertreated. The result is a rapid progression of optic nerve damage and visual field constriction, ending in total blindness for far too many people.
Can SLT help prevent blindness in West Africa?
(Images courtesy of Lumenis)
As we seek to help preserve vision in patients with glaucoma in the region, a possible answer is SLT, whose unique combination of efficacy and safety addresses some of the problems identified above. For more than 20 years, the procedure has been a recognized tool for the treatment of POAG.10
Its mechanism of action is well known: laser-tissue interaction triggers a chain of biological and biochemical reactions that result in enhanced outflow facility and reduction of IOP. SLT lowers IOP at least 20% and keeps patients off medications in about 75% of cases.10 Its also has a superb safety profile, with only minimal and transient reddening of the eye in response to treatment.11,12
What’s more, SLT is effective as a first-line therapy, often eliminating the need for medications. My colleagues and I were the first to publish a study showing the safety and efficacy of SLT as primary treatment,11 and the recent LiGHT study showed it to be superior to medications as a primary treatment over 3 years.10 SLT’s positive outcomes in people of African descent have also been demonstrated.13
Moreover, the procedure is very quick, requiring only about 2 minutes per eye in an office setting. That sets a lower bar for access to care compared with surgery. There is absolutely no pain or discomfort, and patients can resume regular activities immediately after treatment without any limitations.
With these advantages in mind, my fellow ophthalmologists and I chose to introduce this excellent modality in Africa as a safe and effective treatment for glaucoma without the need for chronic medication or invasive surgery and promote its use.
An SLT pilot program in Togo
(Images courtesy of Lumenis)
Our team in Israel organized a special project in Lomé, Togo’s capital and largest city. Three of us traveled there in October 2022s. A Lumenis Digital Duet SLT-YAG laser, donated to the Lomé Commune Centre Hospitalier Régional, was delivered 2 weeks before our arrival.
Several months in advance, our team had worked with the chief medical officer of Togo and his team to outline the project’s concept and primary goals. We wanted to implement SLT in patients with elevated IOP and uncontrolled glaucoma. We set 2 main targets: educate Togolese ophthalmologists and ophthalmic care workers about SLT and its role in glaucoma and examine as many patients as possible in the 6 days we would spend in the hospital.
Our educational efforts were met with enthusiasm. The 14 local ophthalmologists and 10 caretakers who participated in the project were very knowledgeable, motivated to learn, and eager to master the procedure. The program included lectures on SLT as well as practical instruction and demonstrations on real patients.
During our stay, we examined 520 patients, many of whom had been referred to us in advance by local ophthalmologists. Many had already been diagnosed with glaucoma and treated with drugs. Of those we examined, 102 required SLT treatment per the usual criteria of IOP above 21mm Hg despite or without topical treatment. The fact that nearly 20% of patients required SLT—a very high percentage compared with what we see at home—underscored the severity of the condition in Togo.
When we began doing SLT, I treated the patients, and the local ophthalmologists watched me through the Digital Duet’s video system. After 2 days, they had mastered the principles of therapy and had begun treating patients themselves, first under my watch and later completely independently.
We could only evaluate the success of SLT in the acute postoperative period, but results were positive: Within 1 hour after SLT, 90% of patients had an IOP that was lower by 10% to 30% from baseline. Such a prompt response is a very good prognostic sign, and we thought it very encouraging for the future of SLT in Africa.
A model for the future
(Images courtesy of Lumenis)
Following the project’s success, we hope similar programs will be adopted in other African countries. Having experience with many SLT lasers over the decades, our team found that the Digital Duet laser was especially appropriate in this case. Exceptional optics and comfortable ergonomics make it well suited to new users, and its integrated video not only aided our training efforts but could also help our students continue to train others. It’s also a reliable, heavy-duty device that is ideal for economically challenged locations.
Our team was also very grateful for the coordination provided by Togo’s chief medical officer and local ophthalmologists in Lomé. Through professional networks like these, we hope education will continue in Togo and throughout the rest of Africa.
Shlomo Melamed, MD
E: melamed.shlomo@gmail.com
Melamedis a professor emeritus of ophthalmology at the Sackler Faculty of Medicine at Tel Aviv University.
References:
1. Resnikoff S, Pascolini D, Etya’ale D, et al. Global data on visual impairment in the year 2002. Bull World Health Organ. 2004;82:844-851.
2. Budenz DL, Barton K, Whiteside-de Vos J, et al. Prevalence of glaucoma in an urban West African population: the Tema Eye Survey. JAMA Ophthalmol. 2013;131(5):651-658. doi:10.1001/jamaophthalmol.2013.1686
3. Bonnemaijer PWM, Cook C, Nag A, et al. Genetic African ancestry is associated with central corneal thickness and intraocular pressure in primary open-angle glaucoma. Invest Ophthalmol Vis Sci. 2017;58(7):3172-3180. doi:10.1167/iovs.17-21716
4. Cook C. Glaucoma in Africa: size of the problem and possible solutions. J Glaucoma. 2009;18(2):124-128. doi:10.1097/IJG.0b013e318189158c
5. Aikins ER, du Toit Mclachlan J. (2022). Africa is losing the battle against extreme poverty. Institute for Security Studies. July 13, 2022. Accessed January 2023. https://issafrica.org/iss-today/africa-is-losing-the-battle-against-extreme-poverty
6. Dean WH, Buchan JC, Gichuhi S, et al. Ophthalmology training in sub-Saharan Africa: a scoping review. Eye (Lond). 2021;35(4):1066-1083. doi:10.1038/s41433-020-01335-7
7. Oosting RM, Wauben LSGL, Groen RS, Dankelman J. Equipment for essential surgical care in 9 countries across Africa: availability, barriers and need for novel design. Health Technol. 2019;9:269-275. doi:10.1007/s12553-018-0275-x
8. Bambamba J, Murrube N, Pires P, et al. Availability, prices and affordability of glaucoma medicines among private pharmacies of Nampula City in Mozambique. Open J Epidemiol. 2022;12:158-169. doi:10.4236/ojepi.2022.122014
9. Damji K, Nazarali S, Giorgis A, et al. STOP Glaucoma in Sub Saharan Africa: enhancing awareness, detection, management, and capacity for glaucoma care. Expert Rev Ophthalmol. 2017;12(3):197-206.
10. Konstantakopoulou E, Gazzard G, Vickerstaff V, et al. The Laser in Glaucoma and Ocular Hypertension (LiGHT) trial. A multicentre randomised controlled trial: baseline patient characteristics. Br J Ophthalmol. 2018;102(5):599-603. doi:10.1136/bjophthalmol-2017-310870
11. Melamed S, Ben Simon GJ, Levkovitch-Verbin H. Selective laser trabeculoplasty as primary treatment for open-angle glaucoma: a prospective, nonrandomized pilot study. Arch Ophthalmol. 2003;121(7):957-960. doi:10.1001/archopht.121.7.957
12. Latina MA, de Leon JM. Selective laser trabeculoplasty. Ophthalmol Clin North Am. 2005;18(3):409-vi. doi:10.1016/j.ohc.2005.05.005
13. Goosen E, Coleman K, Visser L, Sponsel WE. Racial differences in selective laser trabeculoplasty efficacy. J Curr Glaucoma Pract. 2017;11(1):22-27. doi:10.5005/jp-journals-10008-1216
