Devising and Evaluating an Adaptive Static-Automated Perimetry Test for Children: A Feasibility Study

To assess the feasibility of a Static Automated Perimetry in children test (cSAP) designed to return clinically useful information about a visual field when stopped after any number of presentations while testing the visual fields of children.

The cSAP test was engineered with specific location selection, test logic and data presentation as the core of the perimetric procedure. Some strategies were added to engage children in the test such as fixation markers that changed shape and colour, splitting the test into 'levels' and a small visual and audio reward at the end of each level. The method was run dichoptically on the Topcon Tempo Perimeter using the Open Perimetry Interface. This is a report of a validation study on 10 adults with visual field loss, looking at the differences between the final estimated field and the fields reported after each presentation, as well as comparing to a simulated baseline procedure with the same test logic but random location selection. Additionally, the experience of using the method to test 11 children aged 4-9 years is also reported, with six being retested 3 months later.

Stopping cSAP after any number of presentations always gave a better estimate of the final field than the baseline method in the adult eyes, although four of the 10 differences were small. The youngest child, 4 years of age, had difficulty focussing on the test to get a useful field, but generally all other children engaged in the task and returned a sensible visual field result. There was an obvious learning effect across the re-tested younger children.

cSAP is a feasible method for testing children or others who may not complete a standard visual field test, with design advantages over conventional SAP tests for this purpose.