Postoperative vision-related quality of life and functional vision outcomes with the Argus II Retinal Prosthesis

Abstract

Abstract Background The Argus II Retinal Prosthesis (Second Sight Medical Products, California) was developed to enhance visual outcomes in patients with degenerative retinal diseases. The primary objective of this study was to describe changes in vision-related quality of life based on patient responses to the National Eye Institutes Visual Function Questionnaire (NEI VFQ-25) over a two-year postoperative period. The secondary objective was to assess a relationship between subjective NEI VFQ-25 scores and objective functional vision outcomes. Methods Five patients who were fitted with the Argus II Retinal Prosthesis due to profound retinal dystrophy were assessed in this study. The NEI VFQ-25 was given to patients prior to implantation, at month 12, and month 24 post-implantation. Functional vision data and images from each visit were extracted from the Argus II Retinal Prosthesis Post-Approval Study. Data analysis was completed on IBM SPSS. Results Between Month 0 and Month 24, there was a significant increase in VFQ score in the ‘Social Functioning’ subscale (p < 0.05), and there were other subscale trends towards increase over time. Spearman’s rank-order tests revealed significant positive correlations between various VFQ subscales and functional vision measures. ‘Dependency’ correlated with direction of motion (DOM) (rs = 0.745, p < 0.05) and with electrode array-retina gap distance (rs = 0.778, p < 0.05). ‘General Vision’ correlated with DOM (rs = 0.541, p < 0.05) and with electrode array-gap distance (rs = 0.581, p < 0.05). ‘Role Difficulties’ correlated with DOM (rs = 0.527, p < 0.05). No VFQ subscale correlated significantly with ‘square localization (SL).’ Conclusions In patients with the Argus II Retinal Prosthesis, there may be change in vision-related quality of life over time, as postoperative changes in NEI-VFQ subscales were demonstrated. There may also be a relationship between vision-related quality of life and functional vision outcomes postoperatively, as exhibited by several significant correlations found between NEI-VFQ subscales and both direction of motion and electrode array-retina gap distance. It is essential to assess the role of patient-reported outcome measures and functional vision outcomes in helping clinicians guide long-term postoperative management and in helping innovators develop enhanced retinal implant technology.