Abstract
Purpose :
Astronauts can be affected by Spaceflight Associated Neuro-ocular Syndrome (SANS), including optic disc edema, flattening of the globe, choroidal and retinal folds, and hyperopic refractive shifts. SANS can develop after an extended period in space and across multiple spaceflights. Additional assessment methods are needed to understand the time course, impact, and potential treatment options of SANS. Development of a portable instrument to assess visual field (VF) changes in SANS is a priority as long-duration spaceflights are likely to increase. The purpose of this study was to compare a new mobile, goggle-based visual field device (GBVF) designed for potential use in spaceflight to the Humphrey Visual Field Analyzer (HFA).
Methods :
A total of 50 subjects participated (mean age 45.5). Of these, data were successfully collected for 48 subjects, 24 of whom were previously diagnosed with a VF defect. Participants completed threshold VF testing with HFA 24-2 SITA standard and the GBVF device which used a similar 24-2 protocol. The GBVF device consisted of a head-mounted VF tester running a novel program. Repeated measures ANOVA with VF instrument as a fixed factor was used in all analyses. For quadrant analyses, the quadrant was used as a fixed factor.
Results :
For subjects without a previously diagnosed VF defect, the instrument factor was not significant for any of the analyses (point-by-point comparison: OD p=0.40, OS p=0.52, quadrant analysis for summed decibel levels: OD p=0.68, OS p=0.23, quadrant analysis for average decibel levels: OD p=0.63, OS p=0.24). Overall, 14 right eyes and 13 left eyes were determined to have a VF defect from the sensitivity and grayscale plots or from the HFA pattern standard deviation value. For eyes with a VF defect, the point-point comparison showed a significant difference for the right eyes (p=0.017) but not for the left eyes (p=0.17). The quadrant analyses were not significantly different.
Conclusions :
For both the group with no previously diagnosed VF defects and for the eyes with VF defects, the GBVF and HVF devices produced similar testing results in the quadrant analyses. There was a significant difference between the instruments only for the point-by-point comparison for the right eyes with VF defects. Slippage of the goggle-based device or undetected changes in ocular fixation with the GBVF device may have accounted for the mild differences between the devices noted in one point-by-point analysis.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.