I have combination skin and have never used Accutane. However, when I used Retin-A, it made my face extremely oily, a lot more oily than I have ever been in my life. Of course, my doctor didn't believe me that it was the Retin-A ("Retin-A has the opposite effect- it dries skin out," he said while staring at my extremely oily face), so he switched me to Tazorac which had the exact same effect- super oily. Finally, I saw a nurse practioner who believed me and out me on a BP Wash and topically rx BP which helped immensely.
I will say that my skin's texture and clarity was amazing on the retinoids, but I was so oily that I was embarassed to be in public. Anyway, I just wanted to post because when I went through my retinoid phase, I couldn't find anyone who validated the extra facial greasiness due to retinoids.
Sidenote- I do use Milk of Magnesia (Phillips, but make sure you buy non-scented) under my moistuizer as a base and it helps immensely with greasiness. Put a light layer on after you wash. Let it dry, then apply moisturizer. I never tried it while on the retinoids, though.
Good luck!