I did my first "online exam" on a patient here about a month ago, and I was surprised to find that it was actually fun! No, it's not the same as a live exam in person, but let's face it... many times that's just not feasible due to geographical distance. Also, there are many who for whatever reason (e.g. anonymity, safety considerations) prefer to keep their play strictly online, and that's okay. Others may want to try an online exam first with a potential play partner, and then perhaps consider a real-life exam later if that goes well.
There are different ways to do an online exam. So far I've done several that were chat/text-based. The exam becomes a story that the doctor and patient write together, interactively. Each participant "speaks" just as they would in person, and then indicates (maybe in parentheses) any non-verbal actions. For example:
Doctor: (taking the stethoscope from around my neck)
Doctor: Let me just listen to your heart for a minute...
Patient: Okay, doctor. (smiles)
Doctor: (slips the cool stethoscope under the exam gown, touching her chest)
Patient: Brr! That's a little cold. (shivers)
The more descriptive each person can be and the more the players immerse their minds into what's happening, the more fun it usually is. For what it's worth, I've done a couple of "exams" recently like this, and both patients and I really enjoyed it. Obviously some are better than others. I've had some exams where I wasn't quite sure if I was going the direction the patient wanted me to. For example, why is the patient vociferously protesting about the rectal exam I'm about to do? Is she actually not into that, or does she just want me as the playdoc to show my "stern" side and insist it is for her own good? That's probably where a little extra communication beforehand might have helped, and in fact, there's no rule that says you can't pause in the middle of the exam to clarify something like that.
I have done a "photo-enhanced" exam where the patient sent still pictures focusing on the relevant areas being "examined" at that time. That can be a nice added touch during a chat/text-based exam, but it's not a requirement.
WebCam-based exams are a bit different, and I haven't done one of those quite yet. In a way this would seem a little more difficult. When I tell the patient I'm going to do her breast exam, if it's a real-life exam I proceed to do just that. And if it's a chat-based exam we can at least imagine that my fingertips are palpating her breasts. But on a WebCam, she's obviously just doing a self-exam, which doesn't seem quite as fun. I don't know... maybe after I actually do one of those exams I'll have a different perspective.