Hematoxylin-eosin (HE) Staining
Paraffin sections were dewaxed with xylene and rinsed successively with 99.9%, 97%, 75%, 50% ethanol and distilled water. Then paraffin sections were stained by hematoxylin for 1 - 3 min, rinsed with tap water for 1 min after each step, differentiated with 1% hydrochloric acid alcohol for 20 s, backed to blue with PBS for 30 s. Next, the sections were stained with eosin for 1 min, dehydrated with gradient ethanol, cleaned by xylene, and then sealed with Histomount. The retinas of rats in each group were observed and photographed.