Handheld Oximetric Ophthalmoscope for Enhanced Diagnosis of Retinopathy of Prematurity
Professor Andrew I McNaught
Honorary Professor at the School of Health Sciences, Plymouth University. Consultant ophthalmologist – Cheltenham General Hospital
Retinopathy of prematurity (ROP) is a potentially blinding condition that can lead to retinal detachment and blindness in severely premature and underweight babies. It is associated with abnormal development of retinal blood vessels that may be classified as severity of ‘plus disease’ from a comparison of images of retinal blood vessels with reference characteristics. Early screening and diagnosis of plus disease and adaptation of treatment according to the severity are effective in reducing the development of ROP and preventing blindness. About 5-8% of premature babies develop ROP in developed countries such as the UK where good treatment for premature babies exists, but the incidence is about 30% in middle-income developing countries such as in Latin America and Asia where more premature babies are surviving, but screening for ROP is not as well developed.
Currently screening involves viewing the retina with an indirect ophthalmoscope whilst physically manipulating the eyeball and recording photographs of the retina using a specialised, but cumbersome and expensive ophthalmic camera called a Retcam (approx. £50k each) that is placed in physical contact with the eye and is stressful for the fragile premature baby and the parents and has to be repeated regularly during the first few weeks of life. In light of this, a research group at Oxford University, headed by Dr Rebeccah Slater and Mr CK Patel, is investigating how to measure the stress of ROP eye checks and treatment. The group will investigate how to improve on current techniques to make the process less stressful and painful as this is very important for the baby’s health and development.
Conventional practice dictates that the retinal photographs are studied by clinicians for abnormal shapes in the retinal veins and arteries indicative of plus disease and treatment of the baby is targeted based on the perceived, subjective development of the disease. Current research is developing computer programmes that promise to more objectively and reliably classify the severity of plus disease and improve the selection of the optimal treatment such as laser therapy or cryotherapy (freezing).
However, Professor McNaught in close collaboration with Professor Andy Harvey and colleagues (who built the ROP focused ophthalmoscope and are now developing the prototype at the Department of Physics and Astronomy, Glasgow University), aim to deliver a device that will improve the diagnosis of the ROP and hence reduce blindness in premature babies in the UK and abroad. This will not only use a new design and exploit low-cost consumer technology to produce a camera for a significantly reduced cost compared to a Retcam but it will accurately distinguish between veins and arteries to enhance automated and objective classification of ROP. It will also be non contact thus reducing stress to babies and handheld and highly mobile to greatly improve the usability of the instrument.
In the developed and developing worlds where ROP-specialists are seldom found outside major population centres, the features outlined above will reduce the skill level required to record images and this will be highly suited for use in telemedicine for classification of ROP .