What does it mean when a doctor refers to water behind the eye as macular degeneration?

Wet type: I think he means there is leakage in the macula which is the wet type of macular degeneration.

Wet AMD: There are two type of macular degeneration. The most common and less problematic is dry macular degeneration(amd). About 10% of dry amd to change to wet either blood vessel leaks to macula or bleeding. Thsi can cause vision problem. But, there is a treatment for wet amd. If there is any changes in vsiion, distortion please see an ophthalmologist asap.