Appendix 2: Methods and Analyses
A. State of the Literature
For this updated Advisory, a review of studies used in the development
of the original Advisory was combined with a review of studies
published subsequent to approval of the original Advisory. The
updated literature review was based on evidence linkages, consisting
of directional statements about relationships between specific perioperative
management activities associated with a spine procedure
during which general anesthesia is administered and permanent
impairment or total loss of sight. The evidence linkage interventions
are listed below.