Author Block: Scott Anderson, Adrian Battiston, Donna Bong, Karim Damji

Author Disclosure Block: S. Anderson: None. A. Battiston: None. D. Bong: None. K. Damji: None.

Abstract Body:

Purpose: Visual field testing is routinely used for analysis and management of patients with neurological pathology that impacts the visual fields such as stroke, metastatic and non-metastatic cancers, and trauma. This study investigates the validity of the Humphrey visual field (HVF) testing compared to the octopus visual field testing in detecting and following patients with neurological pathology impacting visual fields. 

Study Design: A single centre, retrospective chart review at the Eye Institute of Alberta located at the Royal Alexandra Hospital in Edmonton, Alberta. 

Methods: This study was approved by the University of Alberta research ethics board. Data were collected from the Eye Institute of Alberta visual field database. All Octopus visual fields used for detecting and monitoring neurological pathology impacting visual fields conducted on adults were conducted from September 2015 to September 2017. After collection of visual field data, 3 blinded reviewers with a prior established inter-rater reliability of >95% assessed if the findings from the octopus visual field assessment would be identifiable on 24-2 sita fast HVF testing based on degree of vision cut-offs of the test. Statistical analysis was conducted on SPSS version 25.0. Level of agreement between Octopus visual field and 24-2 sita fast HVF was measured using basic descriptive statistics. 

Results: In total, 108 patients met inclusion criteria, resulting in 211 individual eye visual fields being scored. Overall 116 (55%) of individual visual fields were abnormal and the sita fast HVF was graded to report the same clinically relevant findings on visual field testing 197 times (93%). Of the 7% not detected 64% were due to the patient being unable to fixate on a I2E or I4E isopter, with and additional 18% suffering from movement disorders resulting in exam difficulty. In total only 1% of total visual fields with good fixation during the exam were graded as inaccurate using a sita fast HVF. 

Conclusions: Octopus visual field testing is widely considered a gold standard visual field test. However, the examination is both burdensome on staff, patients, and overall clinical efficiency. Our results show that a more patient and staff friendly sita fast HVF may be an appropriate alternative test for monitoring, detecting, and following patients with neurological pathology impacting visual fields. However, for patients with severe vision loss or those not able to fixate on isopters I4e and lower in the sita fast HVF would benefit from a more rigorous testing.