Skin gangrene is a very serious necrotic inflammation usually due to Streptococcus pyogenes and Staphylococcus aureus.
Even though its more common in the other parts of the body it can happen in the eyes and it presents with necrosis resulting from a rapidly progressing oedema. The treatment of choice is surgical debridement and parenteral benzylpenicillin.
References
Gangrene of the eyelid Wikipedia(Text) CC BY-SA