There are many threads on application stuff and you can also check out the FAQ poll stuff. But to answer your question shortly, applications are looked at as a whole, not just one aspect. See FAQ for what is "most" important. ie this is what the Wilmer Institute says about their successful residents:
1. Outstanding college and medical school academic records.
2. Board scores above the 90th percentile.
3. Evidence of academic potential as indicated by authorship (especially first-authored) of at least one scientific article (ideally, concerning an ophthalmologic subject) in a peer-reviewed journal.
4. Evidence of commitment to ophthalmology as indicated by involvement (research, electives, etc.) in the ophthalmology department at their medical school.
5. For foreign medical graduates, at least the 90th percentile on the ECFMG examinations
There are many other things that can help or hurt your in your app...