Question: Our ophthalmologist removed a rust ring from a patient's central cornea, using a slit lamp and a burr. Would 65400 be the code for removal of the rust ring, or would 65222 be more appropriate? Massachusetts Subscriber Answer: scrape away the rust-impregnated corneal epithelium.Even though the rust ring is a foreign body, don't be tempted to report 65222 (Removal of foreign body, external eye; corneal, with slit lamp) as the most appropriate code. Code 65400 (Excision of lesion, cornea [keratectomy, lamellar, partial], except pterygium) is also not appropriate since the ophthalmologist is removing a foreign body, not a lesion. Don't forget to append the proper modifier -- LT (Left side) or RT (Right side) -- to specify which eye the ophthalmologist worked on.