For World Glaucoma Week, a Q/A with Heiko Philippin lead researcher on the results of a trial published in Lancet Global Health that shows laser treatment could significantly improve treatment for glaucoma in Africa.
- What is significant about this study? How can it influence the glaucoma treatment regimen and help prevent vision loss?
This study is the first randomised controlled trial exploring the use of this kind of laser treatment in comparison to timolol eye drops for patients with glaucoma in Africa. Globally, the glaucomas are the most frequent cause of irreversible blindness and Africa has both the highest prevalence of the condition and the highest prevalence of blindness due to glaucoma. Rates in Sub-Saharan Africa are predicted to nearly double by 2040.
The study shows that Selective laser trabeculoplasty (SLT) is nearly twice as effective as the standard local treatment, at nearly no extra cost.
- What does the results imply to low- and middle-income settings with high patient volume?
In LMIC settings, eyedrops can be difficult as a form of treatment, as people may forget to continue taking them regularly, and they might be expensive and only obtainable by travelling long distances. In settings with a high patient volume an SLT laser is a perfect addition for a clinic, as the initial cost of the machine can be offset by the savings from multiple patients.
- How does SLT stand out from 0.5% Timolol eye drops? What were the key factors that were considered in the matrix?
The results showed that SLT successfully reduced eye pressure to normal levels (up to 18 or 21mmHg) in significantly more patients after one year (61% of eyes) compared to the standard treatment of timolol (31% of eyes), so was more effective in reaching the clinical goal for glaucoma. SLT also removes problems of adherence and patient burden that come with eye drops, with the study showing that glaucoma patients only need one or two outpatient treatments, so their daily time and personal input into treating their glaucoma is greatly reduced.
The affordability of the treatment was also evaluated. Based on 500 eyes treated each year, and taking into account the cost of the equipment, maintenance and repair, one SLT procedure would cost $12.49 in total, while annual therapy with timolol eye drops cost around $16.32 per eye in Tanzania. Taking into account that some patients would require a second SLT treatment, in spite of the initial costs of the laser equipment, we estimated that around 500 SLT treatments would be a similar price to timolol eye drops for a patient who attends a hospital which serves high volumes of glaucoma patients.
- What evidence gaps did you find and how might these be filled?
The analysis was done for the first year, which allowed evaluation of eye pressure reduction, safety, complications and cost, but was unable to verify differences in long-term loss of sight and quality of life as well as other long-term effects. A longer follow-up period would be able to ascertain these differences between the treatments.
- What could be the positive implications on human resources and economics?
Poor eye health has a knock-on effect on poverty, employment and development. With the number of people affected by glaucoma set to rise, this study shows an innovative way to treat patients with more success for the same cost, at scale, and with a higher chance of adherence to treatment. Higher success and efficiency for this disease can therefore help to improve economic outcomes for people and countries. Using fewer plastic bottles of eyedrops may also help contribute to the sustainability of eye care.
- What could be the focus areas for future research?
Future research could look at a comparison between SLT and other widely used glaucoma treatments, for instance other laser treatments. Future studies in Africa could also test different treatment strategies which include differing combinations of treatments in a stepped-care approach.. They could also include a longer follow-up period.
Image on top: Glaucoma patient Mushi Ebenezer has a checkup with Dr Heiko Philippin at KCMC (project 393) in Moshi, Tanzania on June 8, 2018/CBM/Hayduk