Figure 2

Optical coherence tomography analysis of sodium iodate-induced retinal degeneration with the treatment of GTE and its catechin constituents.

Optical coherence tomography (OCT) images showing the cross-sectional retinal thickness of adult rats 14 days after injection of sodium iodate. (A) Saline control. (B) Injection of sodium iodate alone. Dark blots (white arrows) corresponding to degenerating profiles in the outer retinal layers were observed. (C) Treatment with catechin constituents (GC, EGC and EC) without EGCG [Cat (-EGCG)]. (D–F) The dark blots were highly reduced in the retina for the groups pre-treated with GTE Theaphenon E, or combination of catechin constituents containing EGCG. INL: inner nuclear layer; ONL: outer nuclear layer; IS/OS: inner segment and outer segment of photopigment layer. Scale bar is 200 μm. (G) Quantitative measurements of the thickness of outer nuclear layer in OCT images showed a substantial reduction 7 days after sodium iodate injection. The reduction was significant in the groups pre-treated with Theaphenon E, catechins mixture with EGCG, or EGCG alone, but not with catechins mixture without EGCG. The experimental data were compared with that of the sodium iodate group using Wilcoxon signed rank test, *p < 0.05, **p < 0.01. Data were presented as mean ± SEM.