A comparison of photoscreening techniques for amblyogenic factors in children.

We screened 236 consecutive patients aged 6 years or less using an Off-Axis photoscreener and an Otago-type photoscreener. With a masked standardized clinical assessment as the standard, an overall comparison of the results obtained with the two techniques revealed a sensitivity and specificity in the neighbourhood of 0.85 and 0.87 respectively for the Off-Axis photoscreener and 0.94 and 0.94 respectively for the Otago photoscreener. Both techniques, but especially the Off-Axis technique, were less sensitive and specific in younger children (24 months or less). Fundus colour (light or dark) did not greatly affect sensitivity or specificity. Photoscreening with the pupil dilated led to an increase in false-positive results with both techniques. Our results showed the Otago photoscreener to be superior in this clinical trial.