Screening for eye disorders in remote areas

Untreated eye defects leading to permanently impaired vision and even blindness are a serious problem in the developing world. It's a sad fact that 90% of the world's blind people, amounting to 45 million people, live in developing countries. And many of the conditions causing their blindness, such as glaucoma, diabetic retinopathy and childhood blindness could easily have been treated if detected early enough through screening. Recognizing the scale of this problem, Philips consulted with leading ophthalmologists within India who showed great interest in the development of a simple eye-screening device that could be used by paramedics or people without formal medical training.

Automatic analyzing and diagnostics of the eyes

Essentially the device should be handheld or head mounted, be relatively inexpensive, operate in areas without a regular power grid and embody an 'expert system' capable of automatically analyzing the measurements and giving advice about whether the patient should see a doctor or specialist for treatment, or have medication prescribed in an early phase, when the disease still can be treated. The device embodies three essential functions: a retinal camera, an autorefractor for measuring refractive errors and a tonometer for eye pressure measurement. In contrast to specialist clinical systems, it should also not require calibration.

Translating consumer system insight into ophthalmic healthcare

To address the low-cost requirement, Philips Applied Technologies is drawing on its expertise in consumer systems and is currently developing a prototype retinal camera using a commercially available webcam plus specially developed optics. Although development of the autorefractor has not yet started, feasibility studies indicate that a successful design could use many of the same optical elements as the retinal camera combined with LEDs and photocells to stimulate and measure corneal reflex. It's anticipated that the biggest challenge will be integrating the tonometer into the device. Elevated eye pressure is one of the early indications of glaucoma and the tonometer determines this by measuring the deformation of the eye caused by a brief puff of air. To help meet this challenge, we will utilize the expertise of our mechatronics group. The image processing and interpretation software will be developed in parallel with the hardware, drawing on the company's know-how in imaging software for clinical systems.

The aim is for screening to cost no more than around 60 Euro cents per examination which may be government supported or subsidized by hospitals that will see the screening programs as a means of increasing their patient catchment population. Pharmaceutical companies too, may also be prepared to support screening programs which will inevitably lead to an earlier usage of eye drops or other drugs.

The innovative eye-screening device has already stimulated considerable interest among leading eye hospitals within the developing countries.