Feasibility and Outcome of Automated Static Perimetry in Children Using Continuous Light Increment Perimetry (CLIP) and Fast Threshold Strategy

Purpose: Visual field testing in children is always a challenge as testing is hampered by fatigue effects, easy distraction and lack of comprehension. For that reason new testing strategies for automated perimetry have mainly been evaluated on adults. We tested the feasibility and outcome of automated static perimetry in children in a standard clinical setting.

Methods: Twenty-eight children aged 5-14 years were examined at the Twinfield perimeter, including healthy children, children with unilateral pathologies (normal eye tested) and children with strabismus. Fast threshold strategy (FT) and continuous light increment perimetry (CLIP) strategy were used in a randomized order. One eye per subject was examined and each test was performed twice.

Results: Reliable results were obtained in many children starting from the age of 8 years. In children aged 13 years and over, adult testing strategies were possible in most cases with good reproducibility. No significant difference was found between the children with strabismus and the other children. Mean sensitivity (MS) increased and fixation losses decreased as a function of age. Continuous light increment perimetry showed a lower number of abnormal fields and fewer false-positive errors compared to FT.

Conclusion: Automated static perimetry is possible in many children in a clinical setting using a commercially available Twinfield perimeter in a session of clinically practical duration. Test performance was not only dependent on age, but also on the child's maturity and ability to concentrate. Especially in children up to the age of 8 years, testing with the ramp stimulus (CLIP) was easier than with a staircase strategy (FT).