A comparison of rust-ring removal methods in a rabbit model: small-gauge hypodermic needle versus electric drill

Corneal rust rings are common findings after removal of a metallic foreign body. These rings should be removed to prevent inflammation and scarring. We compared the corneal damage in rabbit eyes caused by rust-ring removal using two different methods: a small-gauge hypodermic needle and a hand-held electric ophthalmic drill. No significant difference was found in the amount of corneal scarring as graded by a masked observer. However, there was a trend toward deeper stromal damage in the drill-treated subjects (207 +/- 73 microns) than in the needle-treated subjects (172 +/- 61 microns). In light of this finding, we suggest caution in removing central rust rings with an electric drill since an avoidable, permanent scar may result.