Table 1.

Evidence suggesting diabetes-induced degeneration of RGCs in humans

Method	Observation	Reference
Histology of autopsy samples	Atrophy of RGC, degeneration of NFL	Wolter 1961; Bloodworth, 1962; Kerrigan et al. 1997
Immunohistochemistry of autopsy samples	Apoptosis of RGC, overexpression of Bax, and activated caspase-9 and -3	Barber et al. 1998; Abu-El-Asrar et al. 2004; Abu El-Asrar et al. 2007; Oshitari et al. 2008
NFL defects detected by red-free photography	Detectable in 20% of diabetics without microaneurysms, and 57% with microaneurysms	Chihara et al. 1993
NFL ‘thickness’ from scanning laser polarimetry	Decreased in diabetic patients, and related to severity of retinopathy	Chihara & Zhang, 1998; Ozdek et al. 2002; Takahashi et al. 2006
NFL ‘thickness’ from scanning laser polarimetry	Decreased in superior retina of diabetic patients	Lopes de Faria et al. 2002