Association between eNOS 4b/a Polymorphism and the Risk of Diabetic Retinopathy in Type 2 Diabetes Mellitus: A Meta-Analysis

Table 1

Main characteristics of included studies in the meta-analysis.

Author	Year	Country	Ethnicity	Case/control	Genotyping methods
Awata et al. [12]	2004	Japan	Asian	117/109	PCR
Cheema et al. [20]	2012	Indian	Asian	842/604	PCR-RFLP
Chen et al. [28]	2007	Ghana and Nigeria	West African	68/301	PCR
Cilenšek et al. [4]	2012	Slovenia	Caucasians	172/405	PCR
de Syllos et al. [14]	2006	Brazil	Caucasians	56/114	PCR
Ezzidi et al. [19]	2008	Bahrain	Asian	383/489	PCR-RFLP
Li et al. [26]	2010	china	Asian	87/79	PCR
Mehrab-Mohseni et al. [21]	2011	Iran	Asian	41/179	PCR
Petrovič et al. [18]	2008	Slovenia	Caucasians	283/143	PCR
Santos et al. [13]	2012	Brazil	Caucasians	407/184	PCR
Suganthalakshmi et al. [22]	2006	India	Asian	120/90	PCR-RFLP
Sun et al. [24]	2004	china	Asian	147/155	PCR-RFLP
Uthra et al. [23]	2007	India	Asian	187/188	PCR
Yue et al. [27]	1994	china	Asian	154/167	PCR
Zhang et al. [25]	2005	china	Asian	119/203	PCR