Scar tissue on the ear drum is usually caused by repeated ear infections. The scar tissue can lead to difficulty hearing and eventually ruptured ear drums. Surgery is one means of avoiding progressive hearing loss or ear drum rupture. No patients have reported taking Scar tissue removal (eardrum).
USCIS normally responds to RFE's within 60 days, however they do not have processing times on how long it takes them to respond. It can be longer than that. I would call the USCIS number: 1 (800) 375-5283 and submit a service request, if you do not hear from them soon.
You will need to respond to the RFE within the timeframe indicated (usually 30 to 90 days, but never longer than 12 weeks) so that the immigration official adjudicating your case will have enough evidence to make a favorable decision. In this article, you will find guidance about how to assemble a convincing RFE response for USCIS.