| Study |
Bias |
| Randomisation process |
Deviations from intended interventions |
Missing outcome data |
Measurement of the outcome |
Selection of the reported results |
Overall |
| Authors' judgement |
Support for judgement |
Authors' judgement |
Support for judgement |
Authors' judgement |
Support for judgement |
Authors' judgement |
Support for judgement |
Authors' judgement |
Support for judgement |
Authors' judgement |
Support for judgement |
| Subgroup 1.2.1 Anesthetic vs placebo, VAS (0 to 10), post‐surgery |
| Verma 1995 |
Low risk of bias |
"Patients were allocated drops based on a random‐number generator, and prenumbered containers were dispensed by the operating surgeon." Baseline characteristics of study participants were partially reported by refractive error groups, not by treatment group. |
Some concerns |
Eye drops were prenumbered and dispensed by the operating surgeon; the reference code was opened 3 months postoperatively. A p‐value was reported along with the pain scores but the authors did not report how the p‐value was derived. |
Low risk of bias |
Data for all 44 participants randomized were analyzed and reported. |
Low risk of bias |
All patients were asked to complete Visual Analogue Pain Charts which consisted of a series of horizontal lines 10 em in length with "no pain" written at one end and "worst pain imaginable" at the other. Both participants and the surgeon were likely masked to the eye drops patients received. All pain score data at pre‐specified time points were reported as mean and standard errors in a figure. |
Low risk of bias |
No study protocol for evaluation but pain scores were reported as a continuous measure. Data for all timepoints pre‐specified were reported in figures. |
Some concerns |
This trial was assessed to be at some concern for bias due to deviations from intended interventions. |
| Subgroup 1.2.2 Anesthetic vs placebo, VAS (0 to 10), post‐trauma |
| Shipman 2021 |
Low risk of bias |
The allocation list was generated by a computer random‐number generator and randomization was performed with numbered, sealed, opaque envelopes issued in sequential order to the physician enrolling the patient in the study. |
Low risk of bias |
The envelopes were opaque to ensure enrolling physicians remained blinded despite the different packaging of the placebo and the tetracaine. The placebo and tetracaine were labeled for the patient as the “study drops” to maintain blinding. Intention‐to‐treat analysis used. |
Low risk of bias |
Loss to follow‐up for 3/59 (5.1%) tetracaine and 4/59 (6.8%) placebo. "Data for all participants who underwent random assignment were analyzed according to group assignment" |
Low risk of bias |
Patients were asked to record pain score measurements on a standard NRS (from 0 to 10 cm), which was appropriate. Both participants and physicians were masked to treatment assignment. Data were analyzed without showing patient ID, i.e. masked to the treatment assignment. |
High risk of bias |
In the methods section, primary outcome data were reported to be analyzed by the Wilcoxon signed‐rank test, whereas in the results section, pain scores were compared and reported as mean difference and its associated 95% CI. |
High risk of bias |
This trial was assessed to be at a high risk of bias due to bias in selection of the reported result. |
