Table 1: Familial clustering of DR.

Type of DiabetesPatients/StudyEvidence for familiar ClusteringReference

Type 1DCCT subjectsOR  =  3.1, 95% CI  =  1.2–7.8[9]
Type 1FinnDiane StudyOR  =  2.76, 95% CI  =  1.25–6.11, Heritability = 52%[13]
Type 2Asian IndiansOR  =  3.37, 95% CI  =  1.56–7.29[10]
Type 2Mexican AmericansOR  =  1.72, 95% CI  =  1.03–2.88[11]
Type 2Find-Eye StudyHeritability = 27%[12]