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General device information from FDA records and a trade publication. This page describes products and general use; it is not medical advice and not a procedure guide.
Short answer
A keratome is a powered ophthalmic device that shaves tissue from sections of the cornea. FDA defines it in 21 CFR 886.4370 as an AC-powered or battery-powered device intended to shave corneal tissue for a lamellar (partial-thickness) transplant, and classifies it as Class I. A keratome blade is the cutting element of a mechanical keratome; FDA also lists a separate product code for reprocessed keratome blades.
Definition and scope
The regulation’s identification reads: “A keratome is an AC-powered or battery-powered device intended to shave tissue from sections of the cornea for a lamellar (partial thickness) transplant.” The classification line is one word: “Class I.” (21 CFR 886.4370, checked 31 October 2026 on the eCFR.)
Microkeratome is the term used for the mechanical devices that cut a thin corneal flap. A CRST Today overview of keratomes (July 2023) describes this family of devices in refractive surgery, where the cut is a lamellar corneal flap.
How keratome systems are used in practice
CRST Today describes two broad groups. Mechanical keratomes can be translational or rotational. In the translational design, the article says the device uses “an oscillating blade that docks to a suction ring.” It notes that disposable, single-use systems exist. The second group is the femtosecond laser, an infrared laser used for the same flap-creation task without a blade.
FDA’s 510(k) record K032836 shows how the clearance language reads for one mechanical device: the Moria SA M3 Microkeratome received a substantially equivalent decision on 18 June 2004, product code HNO. Its summary describes use in making a corneal flap for LASIK, among other procedures needing an initial lamellar resection. This page does not describe how any procedure is performed.
Keratome blade: what the term refers to
In the mechanical designs above, the blade is the part that does the cutting; CRST Today describes it as oscillating (translational designs) or rotating or oscillating (rotational designs) while docked to a suction ring. Whether a blade is single-use or reused is set out in the device’s own instructions for use, and FDA’s classification database carries a separate product code, NKY, for reprocessed keratome blades under the same regulation. Blade materials are a manufacturer specification and are not given here.
Keratome vs keratometer vs femtosecond laser
The three names are easy to confuse. Each row below is tied to a named source.
| Name | What the source says | Source |
|---|---|---|
| Keratome | Powered device that shaves corneal tissue for lamellar transplant; Class I under 21 CFR 886.4370 | 21 CFR 886.4370 |
| Microkeratome | Mechanical keratome with an oscillating or rotating blade docked to a suction ring; creates a lamellar flap | CRST Today, July 2023 |
| Femtosecond laser | Infrared laser listed as the non-mechanical way to create the flap | CRST Today, July 2023 |
| Keratometer | A different instrument. It is not covered by 886.4370 and is not a cutting device. Clinic supply lists that include a keratometer are not listing a keratome. | Distinction drawn from the 886.4370 definition above |
Where it matters for labs, clinics and supply decisions
For anyone holding or reviewing a supplier file, the useful item is the FDA record. FDA’s product classification database lists four product codes under 21 CFR 886.4370: HNO (AC-powered keratome), HMY (battery-powered keratome), MYD (water jet keratome) and NKY (reprocessed keratome blade). The values below for HNO and HMY come from the openFDA classification endpoint, checked 31 October 2026.
| Record field | HNO | HMY |
|---|---|---|
| Device name | Keratome, AC-powered | Keratome, battery-powered |
| Regulation number | 886.4370 | 886.4370 |
| Device class | 1 | 1 |
| GMP exempt flag | N | N |
Both records show the ophthalmic review panel, a 510(k) submission type, and “Eligible” under summary malfunction reporting. That last field connects to Medical Device Reporting (MDR). Class I does not mean the record is empty: these records carry a 510(k) type and are not flagged GMP-exempt. A procurement file for a keratome system can therefore name the regulation number, the product code and the 510(k) number printed on the manufacturer’s own documents, and check them against FDA’s database. For the agency itself, see FDA (Food and Drug Administration).
For other ophthalmic and surgical supplies, compare the optometry clinic supply checklist, the ophthalmoscope guide and the surgical retractor guide.
Common misunderstandings
- “Keratome” and “keratometer” are the same thing. They are not. A keratome cuts corneal tissue; the regulation text defines nothing about measurement.
- Every flap-making device has a blade. The femtosecond laser is described as a separate, non-mechanical approach.
- Class I means no FDA record. The HNO and HMY records exist, with a 510(k) submission type and no GMP exemption.
FAQ
What is a keratome?
FDA defines it as an AC-powered or battery-powered device intended to shave tissue from sections of the cornea for a lamellar (partial-thickness) transplant. It is Class I under 21 CFR 886.4370.
What is a keratome blade?
It is the cutting element of a mechanical keratome. CRST Today describes an oscillating blade that docks to a suction ring in translational microkeratomes, and notes that single-use or disposable systems exist.
Is a keratome the same as a microkeratome?
Microkeratome is the term used for the mechanical flap-cutting devices, such as the one in FDA record K032836. Both fall under the same regulation, 21 CFR 886.4370; the AC-powered and battery-powered keratome product codes are HNO and HMY.
Is there an FDA product code for keratome blades?
Yes. FDA’s classification database lists NKY, “Blade, Keratome, Reprocessed”, as Class I under 21 CFR 886.4370, with a 510(k) submission type.
Sources
- 21 CFR 886.4370, Keratome: https://www.ecfr.gov/current/title-21/section-886.4370 (checked 31 October 2026). Also at https://www.law.cornell.edu/cfr/text/21/886.4370.
- FDA product classification, codes HNO, HMY, MYD and NKY, via openFDA: https://api.fda.gov/device/classification.json?search=regulation_number:886.4370 (checked 31 October 2026).
- FDA 510(k) K032836, Moria SA M3 Microkeratome, decision 18 June 2004: https://api.fda.gov/device/510k.json?search=k_number:K032836 (checked 31 October 2026).
- CRST Today, “Keratomes in Ophthalmic Surgery”, July 2023: https://crstoday.com/articles/july-2023/keratomes-in-ophthalmic-surgery (checked 31 October 2026).
