PandAcuity in paediatrics: a novel clinical measure of visual function based on the panda illusion.

BACKGROUND/AIMS: To evaluate the PandAcuity test for visual function testing in a paediatric cohort and to examine its agreement with conventional visual acuity (VA) testing. METHODS: PandAcuity scores were determined in 152 children (77 males) aged between 3 and 15 years after VA testing (LEATM-test, E-chart, Landolt-C-rings or numbers). The PandAcuity test consisted of illusions made up from silhouettes of animals 'hidden' within zig-zag-patterns of decreasing spatial frequencies. Correlation analyses between PandAcuity score and VA were performed. RESULTS: 150 children completed the test in at least one eye, 148 in both eyes. The PandAcuity test demonstrated good test-retest reliability (intraclass correlation coefficient=0.89) between two runs. VA and PandAcuity score showed a medium to large correlation (Spearman's ρ=0.52, p<0.0001). 93% of the children's visual impairment was classified in the same range by both test types. Receiver operating characteristic analysis of predicted visual impairment showed an excellent agreement with the classification based on VA testing (AUC=0.84). CONCLUSION: The PandAcuity test is rapid, simple and well accepted, rendering it a suitable supplement for the clinical assessment of VA in children. Because of its counterintuitive application (a higher number of correctly identified images means worse VA), it can be used to cross-validate conventional acuity tests to assure children's compliance.

Electronically monitored occlusion therapy in amblyopia with eccentric fixation.

PURPOSE: Amblyopia with eccentric fixation, especially when not diagnosed early, is a therapeutic challenge, as visual outcome is known to be poorer than in amblyopia with central fixation. Consequently, treatment after late diagnosis is often denied. Electronic monitoring of occlusion provides us the chance to gain first focussed insight into age-dependent dose response and treatment efficiency, as well as the shift of fixation in this rare group of paediatric patients. METHODS: In our prospective pilot study, we examined amblyopes with eccentric fixation during 12 months of occlusion treatment. We evaluated their visual acuity, recorded patching duration using a TheraMon®-microsensor, and determined their fixation with a direct ophthalmoscope. Dose-response relationship and treatment efficiency were calculated. RESULTS: The study included 12 participants with strabismic and combined amblyopia aged 2.9-12.4 years (mean 6.5). Median prescription of occlusion was 7.7 h/day (range 6.6-9.9) and median daily received occlusion was 5.2 h/day (range 0.7-9.7). At study end, median acuity gain was 0.6 log units (range 0-1.6) and residual interocular visual acuity difference (IOVAD) 0.3 log units (range 0-1.8). There was neither significant acuity gain nor reduction in IOVAD after the 6th month of treatment. Children younger than 4 years showed best response with lowest residual IOVAD at study end. Efficiency calculation showed an acuity gain of approximately one line from 100 h of patching in the first 2 months and half a line after 6 months. There was a significant decline of treatment efficiency with age (p = 0.01). Foveolar fixation was achieved after median 3 months (range 1-6). Three patients (> 6 years) did not gain central fixation. CONCLUSION: Eccentric fixation is a challenge to therapy success. Based on electronic monitoring, our study quantified for the first time the reduction of treatment efficiency with increasing age in amblyopes with eccentric fixation. Despite some improvement in patients up to 8 years, older patients showed significantly lower treatment efficiency. In younger patients with good adherence, despite poor initial acuity, central fixation and low residual IOVAD could be attained after median 3 months. Hence, the necessity of early diagnosis and intensive occlusion should be emphasized.