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, your physician or the facility will need to call and request precertification at least 14 days before the date you are scheduled to be admitted. You or your physician should call prior to the outpatient care, treatment or procedure if possible; or as soon as reasonably possible. For an emergency admission: You, your physician or the facility must call within 48 hours or as soon as reasonably possible after you have been admitted.