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: Disease activity markers , including signs of ocular inflammation , evidence of retinal vasculitis , Swedish interactive threshold algorithm - short wavelength automated perimetry Humphrey visual field analysis , electroretinographic parameters , and optical coherence tomography were recorded .
### Output Text:
Disease activity markers , including signs of ocular inflammation , evidence of retinal vasculitis , Swedish interactive threshold algorithm - short wavelength automated perimetry Humphrey visual field analysis , electroretinographic parameters , and optical coherence tomography were recorded . 