Where are you? I have not seen diamox used for macular edema for quite some time. More common treatments are nonsteroidal anti-inflammatory drops, steroid drops, and kenalog injections subtenons, and sometimes intravitreal. You should see a board-certified ophthalmologist that is a retinal specialist. Unfortunately the macular edema with RP can be quite stubborn and difficult to improve. It is really more a part of the RP disease rather than a result of the cataract surgery - at least usually.
MJK MD