Together with collaborators at King’s College London, researchers from Oxford Population Health’s Economics of Population Health Research Centre have demonstrated the importance of conducting long-term safety follow-up for ophthalmology trials. The study, which looked at whether robot radiotherapy could improve treatment for eye disease, is published in The BMJ. The economic evaluation of the study is published Health and Quality of Life Outcomes.
In the Stereotactic Radiotherapy for Wet AMD (STAR) trial, a custom-built robot was used to treat wet neovascular age-related macular degeneration (AMD), administering a one-off, minimally invasive dose of radiation, followed by routine treatment with injections into their eye.
Wet AMD is a leading cause of blindness and is treated with regular injections into the eye, which are expensive for the NHS and burdensome for patients.
Data from the first two years of the STAR trial suggested that robot radiotherapy of the eye could reduce the number of injections to the eyes while maintaining vision, and was projected to generate cost savings for the NHS. However, extended follow-up showed that the vision of patients who received radiotherapy worsened beyond this initial time period. This safety issue would have gone undetected had follow-up ended at two years, as is common in trials in this area.
Regulators, such as the U.S. Food and Drug Administration (FDA), now require manufacturers of diabetes and cardiovascular drugs to conduct cardiovascular outcome trials with extended follow-up, to ensure that new treatments do not increase long-term cardiovascular risk. The STAR trial highlights the value of long-term safety follow-up for ophthalmology, suggesting that long term safety studies may be needed for drugs and devices beyond cardiovascular disease.
Notably, the cost of the additional safety follow-up was small: recalling patients for a safety visit at Year 3 and Year 4 doubled the length of follow-up with minimal trial expenditure. It also maintained “masking”, whereby patients did not know whether they had received radiotherapy or not.
The study also evaluated how patient-reported outcome measures performed in this population. Helen Dakin, Associate Professor at Oxford Population Health and senior author of the study, said
This is one of the first studies to report findings using the EQ-5D vision bolt-on in the clinical setting. These insights could inform future research on vision-related quality of life measures and cost-effectiveness analyses in retinal trials.
EQ-5D is a short questionnaire used to measure health-related quality of life and inform healthcare decisions. The vision bolt-on is an extra question, which is added to EQ-5D to capture problems with vision as well as other aspects of health-related quality of life.