Digital Imaging Versus Ophthalmoscopy

Congenital Cataract

Cataract (cloudiness of the lens) is the major cause of avoidable child blindness in the world and affects 1 in 3000 UK infants. Screening may fail to detect a cataract in an affected child (false-negative) or mistakenly suggest there is a cataract (false positive) triggering urgent unnecessary referral. Screening is currently undertaken using an ophthalmoscope into the eye to assess the reddish reflected light (red-reflex). This study aims to test if screening using a new hand-held digital imaging device (Neocam) is more accurate than the ophthalmoscope for newborn eye screening.

Cataract (cloudiness of the lens) is the major cause of avoidable child blindness in the world and affects 1 in 3000 UK infants. Cataracts are present in both eyes in more than half of the babies affected. Surgery is required by 8 weeks of age to prevent permanent visual impairment at this critical time of vision and brain development. All UK babies are examined (screened) for cataract twice within the first 8 weeks of life but late diagnosis continues to be a problem, causing avoidable visual impairment in some affected children. Screening may fail to detect a cataract in an affected child (false-negative) or mistakenly suggest there is a cataract (false positive) triggering urgent unnecessary referral, parental anxiety and wasted NHS resources. Screening is currently performed by midwives and doctors shining a bright white light torch (an ophthalmoscope) into the eye to assess the reddish reflected light (red-reflex), similar to red eye seen in flash photos. Cataract causes a dark shadow on the red-reflex but the test can be difficult because bright light causes the pupils to constrict and the babies to forcefully shut their eyes. Assessment is particularly difficult in ethnic minority infants since eye pigmentation affects the hue and brightness of the red-reflex. This study aims to test if screening using a new hand-held digital imaging device (Neocam) is more accurate than the ophthalmoscope for newborn eye screening. Neocam painlessly images the eye's reflection firstly to infrared light and then to a brief green light flash. Its infrared light causes no pupil constriction or avoidance response and the reflection is bright and consistent regardless of the baby's ethnicity. Its brief green flash and immediate imaging allows a photo of the red-reflex to be captured before the pupil has time to constrict. To compare the accuracy of both tests, the investigators seek to enrol 140,000 newborn babies in a two year study period. All babies will have both the current ophthalmoscope screening test and additional Neocam imaging. If either test is potentially abnormal, the baby will be referred for specialist examination. A more accurate screening test could prevent life-long disability and reduce costs to the NHS and society. This study will allow a future estimation of what these savings might be and whether changing to a digital imaging screening service might be justified. The result may have an impact on eye screening world-wide to prevent childhood blindness from cataract.