Macular edema is a condition when leaking blood vessels in the retina causes fluid to accumulate in the macula. This condition sometimes is seen after a cataract surgery or with patient s suffering from Retinitis pigmentosa or may be less spontaneous. There are various types of macular edema such as:

a) Cystoid macular edema: cystoid in nature seen after intraocular surgery.

b) Seen in central branch retinal vein occlusion

c) Seen in inflammatory disease like uveitis, scleritis, toxoplasmosis,retinitis pigmantosa

d) Also seen in diabetic retinopathy

e) Age related macular degeneration.

The symptoms in this condition include blurring of vision and distortion of vision. It is usually diagnosed by an ophthalmologist who confirms it with fluorescein Angiography of the fundus of the eye. It can also be seen in optical coherence Tomography. Yes in regard to your question, the steroidal injection generally causes increase in intraocular pressure that has resulted in the return of macula edema. The effect of steroids decreases over a period of time.