I'm not an IMG, but I've worked with a few IMGs that have matched into residency in the past. Two of them were ophthalmologists in their home country.
This has already been mentioned and has been said thousands of times, but it's very difficult to match as an IMG and the odds are stacked against you. You have to excel in everything in your application, and then some. It's because there are so many qualified US applicants that IMGs are usually weeded out in the first review of applications. The ones I know that have matched have usually done either a pre-residency fellowship (like ocular pathology) or have done extensive research with an ophthalmology department. Most often, they match at where they did their research or pre-residency fellowship, or with a program with extensive connections to the department they were at.
What I'm getting at is that for a back-up option, it may be wiser to do a pre-residency fellowship or research instead of pursuing a transitional/intern year then applying for a residency spot.