strange growth leaves

there are a couple of factors that can cause "strange" growth.. one could be a calcium deficiency, however looking at the rest of the leaves, they look fine, so that's unlikely.. another option could be some kind of burn, but that doesn't seem too likely either another possibility is some kind of "injury", which i believe might have happened here.. when we look at the affected leaves, i see they are exactly opposite of each other and the deformation is on the same side. so if anything happened to the plant at that side, when those leaves were small and just coming out, then such a uniform pattern would be seen. If it only affects those two leaves that i can see from this picture, and not new growth, then i wouldn't worry about it.