In the sentence extracted from biomedical literature, identify all the chemical entities. The required answer format is the same sentence with HTML <span> tags to mark up specific entities. 
### Entity Markup Guides:
Use <span class="chemical"> to denote a chemical.

### Input Text: CONCLUSIONS : The OCT results in these patients with EMB - induced optic neuropathy show considerable loss especially of the temporal fibers .
### Output Text:
CONCLUSIONS : The OCT results in these patients with <span class="chemical">EMB</span> - induced optic neuropathy show considerable loss especially of the temporal fibers . 