Study of Optimal Perimetric Testing in Children (OPTIC): evaluation of kinetic approaches in childhood neuro-ophthalmic disease.

AIMS

We compared feasibility, quality and outcomes of visual field (VF) testing in children with neuro-ophthalmic disease between the discontinued 'gold-standard' Goldmann and Octopus perimeters.

METHODS

Children with neuro-ophthalmic disease, attending Great Ormond Street Hospital, London, were assessed using standardised protocols by one examiner in a single sitting, using Goldmann and Octopus kinetic perimetry. Outputs were classified to compare severity of loss and defect type. Test quality was assessed using both qualitative and quantitative methods.

RESULTS

Thirty children (40% female) aged 5-15 years participated. Goldmann perimetry was completed in full by 90.0% vs 72.4% for Octopus. Inability to plot the blind spot was the most common reason for not completing testing. Over 75% completed a test in ≤20 min. Duration was similar between perimeters (paired t-test, mean difference: 0.48min (-1.2, 2.2), p=0.559). The lowest quality tests were for Octopus perimetry in children <8 years, without significant differences between perimeters in older children (McNemar's test, χ=1.0, p=0.317). There was broad agreement between Goldmann and Octopus outputs (good quality, n=21, Bland-Altman, mean difference for isopters I4e (-514.3 deg (-817.4, -211.2), p=0.814), I2e (-575.5 deg (-900.1, -250.9), p=0.450) and blind spot (20.8 deg (5.7, 35.8), p=0.451)). However, VF severity grades and defect type matched in only 57% and 69% of tests, respectively. Octopus perimetry underestimated severe VF defects.

CONCLUSIONS

Informative perimetry is feasible in children ≥8 years with neuro-ophthalmic conditions, with either Goldmann or Octopus perimeters. However, meaningful differences exist between the two approaches with implications for consistency in longitudinal assessments.