My doctor has said that there are some small holes in my retina and he says they were there since a long time, how serious is this.?

Retinal holes: Many people have long-term small retinal holes which may pose little or no risk. These are different from an acute symptomatic retinal tear (acute onset of floaters and / or flashing lights). Acute retinal tears should be treated to help prevent retinal detachment. Your examining eye doctor should be able to tell which retinal problems need to be treated, and which can just be watched over time.

Not serious: Retinal holes are common. They just need to be followed unless high risk characteristics are present (fluid, high myopia, history of retinal detachment in patient or family, evidence of traction, etc). If high risk, you may need laser treatment.