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: During the follow - up , 3 patients ( 12 % ) developed steroid - induced elevated intraocular pressure ( IOP ) that resolved after corticosteroid therapy was discontinued .
### Output Text:
During the follow - up , 3 patients ( 12 % ) developed <span class="chemical">steroid</span> - induced elevated intraocular pressure ( IOP ) that resolved after <span class="chemical">corticosteroid</span> therapy was discontinued . 