It really depends on your step 1 score. If you did well on step 1, I would highly recommend putting it off so as not to have the possibility of performing worse on step 2. But if Step 1 was not as strong as you would wish for Ophthalmology (>225) you might want to consider taking it early. I wouldn't just take it early to just get it over with because if you do poorly, it may ruin your application.
To add to the previous post, I would say that if you decide to take step II and make the score available for the ophtho match, study hard and you could improve your score. Step II, like Step I, is a scaled score, and since many students put off step II and don't really try that hard, I believe it is easier to do well on it as compared to step I. I almost got the same score on both after only studying a week for step II after the match, when I studied much more for step I...
But if you have a good step I, don't take the risk. Good luck!