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: Treatment outcomes of interest were noted at baseline , before fluocinolone acetonide implant , and then at 6 months , 1 year , 2 years , 3 years , and beyond 3 years .
### Output Text:
Treatment outcomes of interest were noted at baseline , before <span class="chemical">fluocinolone acetonide</span> implant , and then at 6 months , 1 year , 2 years , 3 years , and beyond 3 years . 