For patients with advanced glaucoma, there are no treatments to reverse severe sight impairment (blindness). Support in the community is essential but requires a certificate of visual impairment (CVI) signed by a consultant ophthalmologist. The criteria for certification are ambiguous and subjective, relying on ophthalmologists’ clinical judgement. As a result, many eligible patients miss out on guidance and support from local authorities, with patients from underprivileged communities more likely to be affected.
Although certification guidance is ambiguous, it is based on visual function tests that can be mapped to more objective criteria. However, using these criteria is too labour intensive for ophthalmologists working in busy clinics.
Glaucoma Field Defect Classifier (GFDC) is a web-application that was developed to automate the process of applying objective criteria to help identify patients that are CVI-eligible and thereby improve the provision of support.
After an initial proof of concept study demonstrating that GFDC is perfectly accurate, it was used by student researchers from University of Cambridge in a large study led by Arun Thirunavukarasu, Nikhil Jain, and Professor Rupert Bourne. Glaucoma patients with blindness were identified and 37% were found not to be registered for a CVI. There were many reasons for missed registration, including administrative failure, frailty or other co-morbid health problems, mental health problems, and visual impairment deemed reversible. The project demonstrated how a semi-automated algorithm can be applied to identify patients missing out on a CVI, who may then be offered registration.
GFDC is freely available online (https://gfdc.app) and the research team are able to offer support to those interested in deploying it. Potential use cases extend beyond identifying CVI-eligible patients to identification of patients with progressive disease and clinical trial recruitment, and work is ongoing in these spaces.
To learn more about this exciting new tool, be sure to keep an eye out for our upcoming Glaucoma Supplement, in which study lead Arun Thirunavukarasu discusses its development and application in more detail.
