Inspect the lettering
Select the image and use the artwork text tools to inspect detected words. Check the spelling against the original, especially small labels, numerals and names.
Choose a correction
Review the selected region before changing it. Keep genuinely editable text as a separate layer when it needs regular updates. For a painted-in headline, review the proposed artwork revision and its quoted cost.
Check the surrounding artwork
Zoom in on the corrected region to check the background, letter shapes and neighbouring words. Inspect the full slide again before accepting the revision.
Example brief
Can I correct a number in a photographed chart?
OCR can help locate a printed label. Changing that label alone does not change the bar height or the underlying data. Rebuild the chart from its source table when the value affects its meaning.