A computerised screening for visual field defects in

​Rigshospitalet, University of Copenhagen:

Computerized screening for visual field defects in brain injury patients Maria

1 Nordfang ,

Valdemar

2,3 Uhre ,

Julia

4 Robotham

& Randi Starrfelt4

1 ​ Rigshospitalet,

Department of Neurology 2 ​ Danish Research Center for Magnetic Resonance, Hvidovre Hospital 3 ​ Research Unit, Child and Adolescent Mental Health Centre 4 ​ University of Copenhagen, Department of Psychology

​BACKGROUND ​CHALLENGES

​Cerebral visual disorders are common after acquired brain injury. Prevalence estimates range around 30-40 % (e.g., Kerkhoff, 2000).

​Cerebral visual disorders are at risk of not being thoroughly assessed: • During hospitalization other issues can appear more urgent to the staff • Patients do not always realize the extend of a deficit. • Not all patients can cooperate to a full perimetry test (cognitive and mobility issues may prevent participation) • Waiting lists can be long • Visual field defects can change shape and extent from acute to subacute to chronic phases

​Cerebral visual disorders influence the patients’: • Functional level at discharge • Experienced quality of life • Ability to take part in rehabilitation activities • Can hamper the assessment of other cognitive disorders ​Visual field defects are among the most common cerebral visual disorders.

c-VFT ​GENERAL SETUP A COMPUTERIZED VISUAL FIELD TEST • Runs in PsychoPy, free software (see http://www.psychopy.org/ ) BASIC • Initial screen fitting makes c-VFT usable for all • Short training screens more than 21 cm high. • 48 test points from 1 – 10 degrees • Duration: 5-10 mins • Central fixation task, color change detection • Can be used on both desktops and laptops • Immediate and easily interpretable output • Horizontal midline is probed • C-VFT available for free (soon) ADVANCED SETTINGS • Runs offline • 2-4 repetitions • All four quadrants are probed • Central task change • Display rotation DISCLAIMER C-VFT is a screening tool, not a diagnostic tool! Cannot replace a perimetry nor ophthalmological assessment

​PRELIMINARY DATA ​Patients with visual field defects following stroke. ​LONDON DATA

​COPENHAGEN DATA

​Eleven patientes (eight men) were tested on c-VFT (each point tested twice) and Octopus Esterman test (binocular, covers 75 visual degrees).

​Five participants (all men) were tested on c-VFT (each point tested four times) and on the gold standard.Humphrey i750 Field Analyser (HFA), central 10-2.

​ANALYSIS ​The 48 test points in the c-VFT correspond to 10 test points in the Octopus Esterman test. ​Rough comparison: binary notation of any defect (< 1% in the Octopus Esterman test) in the central 10 degrees of a quadrant. ​Overall correlation was highly significant, S = 6494, p < .001, ​Spearman’s rho = 0.54 c-VFT (binocular test)

​ANALYSIS ​Eight of the 48 test points in the c-VFT correponded directly to points in the HFA. The remaining c-VFT and HFA points were compared by averaging over the adjacent points in the HFA (outer two perimeters) and by averaging over the central c-VFT points in each quadrant (inner two perimeters). ​Overall correlation was highly significant, t(138)= 11.06, p < 2.2e16, Pearson’s r = 0.69 Taking HFA as the gold standard c-VFT sensitivity of .83 across all compared points and participants. c-VFT specificity of .89 across all compared points and participants. c-VFT (binocular test)

Humphrey i750 (central 10-2) Pattern deviation plots Left eye

Right eye

Octopus Esterman test (binocular test)

CONCLUSION: Promising results. More data needed…