Risk of bias assessment
Three RCT studies reported the randomization process, intervention
deviation, yet none of them had selective reporting and outcome data
missing. The study of Qian L30 did not describe the
approach of random sequence generation and potential intervention
deviation. Vasavada et al.22 reported that the surgery
type was revealed to the surgeon and outcome examiner in their study.
The details of risk assessment for these RCTs were presented in the
Figure 2.
Retrospective studies were assessed based on
NOS.
Five studies described the detailed process of cohort selection, and
were assessed
to
be of low risk in cohort selection. The study by Autrata et
al.31 did not report the source of study subjects, and
was assessed to be of medium risk in cohort selection. High risk was
found in the cohort selection in the study by Trivedi et al32,
as
the source and preoperative data on patients were not described. Given
the age at the surgery and the age at the last visit were significant
factors for the postoperative outcomes in cataract infants, these two
factors were used to assess the cohort comparability. According to our
inclusion and exclusion criteria, all these retrospective studies have
similar age at surgery and last visit in both groups. So, all these
studies were assessed to be of low risk in the cohort comparability. The
study by Trivedi et al32.
was assessed to be of high risk
since they did not report the duration of follow up and rate of
follow-up loss. Except for the above study, all the other studies gave
detailed information on outcome assessment. The details of risk
assessment for these retrospective studies were shown in the Figure 3.