3.1 Characteristics of eligible studies
The literature search flow chart is
shown in Figure 1. After screening 1138 articles and registered clinical
trials, a total of 16 studies between 2005 and 2022 were included in the
meta-analysis according to predetermined criteria, involving
834
eyes (575
patients).22-37 The main characteristics of the
selected studies are collated in Table 1. Among the 16 RCTs, 1
studie was registered and 15
studies were published in English. The diseases involved were diabetic
macular edema (11 RCTs), diffuse diabetic macular edema (DDME) (2 RCTs),
refractory diabetic macular edema (RDME) (1 RCT), and macular edema
associated with branch retinal vein occlusion (BRVO-ME) (2 RCTs). Of the
included studies, 13 were two-arm studies and 3 were three-arm studies.
Subsequently, we divided
interventions into a placebo group and the following 4 groups: IVTA,
RITA, SCTA, and STiTA. Fourteen RCTs involved IVTA compared with other
routes of TA administration (the retrieved routes of administration
contained RITA, SCTA, and STiTA); 6
RCTs compared TA to placebo (the retrieved routes of TA administration
contained IVTA, STiTA and RITA); and 3 RCTs both the intervention group
and the control group received intravitreal bevacizumab, which was a
full-length humanized monoclonal antibody against vascular
permeability-associated endothelial growth factor. The baseline
characteristics included the overall proportion of men, 52.01%; age,
ranging from 39.5 to 76.67 years; and length of follow-up, from 12 to 24
weeks. In addition, none of the
trials were funded by pharmaceutical companies.