Walker 1988.

Methods	A randomised, double‐blind, prospective, parallel group study with an independent observer
Participants	Intervention: peripheral laser Diagnostic criteria of patients included in the trial          9 on medications 9 no medications “accepted criteria for TN”. "No previous surgical procedures"     Age mean (range)                                 29 to 78 Gender 9 male, 9 female Severity VAS Duration of condition (range) years 1 to 18 yrs Number        18     Control: peripheral sham Diagnostic criteria of patients included in the trial            10 on medications 7 no medications “accepted criteria for TN”, "No previous surgical procedures" Age mean (range)                38 to 78 Gender 7 male, 10 female              Severity VAS Duration of condition mean (range) years 2 to 20 yrs Number          17
Interventions	Intervention: peripheral laser Helium neon laser 632.5 nm,1 mW, 20 Hz Radial, median, ulnar, saphenous bilaterally, 3 painful facial area where exposure increased 30 s 1 week, 45 s second week, 60 s third to sixth week, 90s 7th to 10th week. Three times a week for 10 weeks   Length of follow‐up mean (range, SD) month Not available Control: peripheral sham Sham machine Radial, median, ulnar, saphenous bilaterally, 3 painful facial area where exposure increased 30 s 1 week, 45 s second week, 60 s third to sixth week, 90 s 7th to 10th week. Three times a week for 10 weeks Length of follow‐up mean (range, SD) month Not available
Outcomes	Primary outcome Pain relief  VAS 0 to 100 and VRS 0 to 100.  1. low pain 0 to 25, 2, moderate pain 26 to 50, 3. moderate high pain 51 to 75, 4. high pain 76 to 100 reported weekly Time of measurement 6 months, 1 year, yearly intervals Kaplan‐Meier Adverse events not stated
Notes	Although this was described as a randomised controlled trial of laser therapy there are insufficient details provided to exclude bias. Care was taken to ensure everyone was blinded to the treatment and assessments were done independently. The outcome measures do not provide individual results but are reported as variances from initial baseline. Improvement was reported after 10 weeks in those with more severe pain. However, no details provided as to overall versus triggered branch relief or whether medication as stopped or reduced.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Subjects randomly assigned
Allocation concealment (selection bias)	Unclear risk	No details
Blinding (performance bias and detection bias) All outcomes	Low risk	All subjects closed their eyes during the laser or placebo administration and thus could not see or feel whether they were receiving experimental or control treatment.  Each technician administered both experimental and sham therapy and was allowed to participate for a maximum of 2 months before being rotated to another project. Recording of pain and of drug histories was done by a third team of researchers that was given only the coded name of each subject and did not know which condition was experimental and which was placebo
Incomplete outcome data (attrition bias) All outcomes	Low risk	“missing scores were assigned the mean pain rating for that group for the rest of the week"
Selective reporting (reporting bias)	Unclear risk	No details
Other bias	Unclear risk	Not possible to ascertain