Comparative evaluation of Octopus semi-automated kinetic perimeter with Humphrey and Goldmann perimeters in neuro-ophthalmic disorders

PURPOSE: The aim of this study was to compare the performance of Octopus 900(OVF) kinetic module with Goldmann perimeter (GVF) and Humphrey 750i (HVF) perimeters in neuro-ophthalmic disorders. METHODS: During this prospective observational cross-sectional study, 17 patients (26 eyes) with neuro-ophthalmic disorders underwent visual field examination on the three perimeters. Field defects on OVF were matched with HVF and GVF for the number of quadrants involved. An unmasked observer, and a masked observer (unaware of the clinical diagnosis) were made to separately diagnose the type of field defects on all three fields for the same patient. The pattern of field defect on OVF was compared with GVF and HVF field defects for both observers. RESULTS: When OVF was compared with HVF and GVF, 88% eyes correctly matched for normal or abnormal visual fields, while quadrant-matching was 80% and 89% respectively. For the unmasked observer, the pattern of field defects on OVF was similar to HVF and GVF in 58% and 65% eyes respectively while for a masked observer, it was 54% and 62%. Central and paracentral scotomas showed unmatched fields when OVF was compared with HVF and GVF. When these patients were excluded, sensitivity of OVF increased to 95%. CONCLUSION: Clinical correlation aids in better characterisation of a field defect. All 3 perimeters are concurrent in the pattern of field defects for non-central defects. However, the default protocol on OVF may not be enough to demarcate the central and para-central scotomas. Development of a customised protocol for the assessment of central and centrocecal field defects increases the accuracy of OVF.