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General product and regulatory information for laboratory, clinic and supply staff. This page is not medical advice and does not describe how any procedure is performed.
Short answer
A crescent blade, also called a crescent knife, is a single-edged ophthalmic hand instrument with a curved, rounded-tip blade. In FDA’s product classification it falls under product code HNN, “knife, ophthalmic”, a Class 1 device. Catalog entries describe it by blade width, bevel direction, shape and handle type.
Definition and scope
The U.S. National Library of Medicine’s AccessGUDID database lists crescent knives under the GMDN term “Ophthalmic knife, single-use” (GMDN 46741). That term describes a hand-held, manual ophthalmic surgical instrument with a sharp, single-edged blade at the distal end and a handle at the proximal end, used for precise incisions in the eye and surrounding tissues. One AccessGUDID record, “Crescent Knife 1.2 mm Bevel Up Angled with protection” from AKTIVE SRL (catalog C-12/AP), states that it is a single-use device.
The phrase “crescent blade” is also used for unrelated things, such as kitchen mezzaluna knives, fantasy weapons and crescent-pattern snips. This page covers only the ophthalmic instrument.
A crescent knife is a different instrument from a general-purpose surgical scalpel; for that, see what a scalpel is. For the clinical field in which it is used, see what ophthalmology is.
How it is described in practice
Manufacturers describe the product, not a technique. pfm medical’s FEATHER Crescent Scalpel page describes a sharp blade with straight sides and a rounded tip, with ultra-sharp edges produced by double-honing. It lists a stainless-steel blade with a 45 degree cutting-edge angle. Three versions are named: bi-bevel, bevel-up and bevel-down.
That page states the product is supplied sterile and gamma-sterilised. With a plastic handle it is single-use only; with an aluminium handle, the manufacturer states it can be resterilised by autoclave after cleaning. The aluminium handles are colour-coded, and a delivery unit contains 5 pieces.
Types and how to read a crescent knife spec line
Catalog lines combine several attributes. The table lists attributes that appear in the AccessGUDID records and the pfm medical product page. Values differ between manufacturers, so a width from one maker is not a standard.
| Attribute | What the records show | Source |
|---|---|---|
| Width or size | AccessGUDID records list a 1.2 mm and a 2.0 mm crescent knife. pfm lists 2.6 mm and 2.2 mm widths. | AccessGUDID; pfm medical |
| Bevel | Bevel up, bevel down and bi-bevel versions are named. pfm’s ordering table lists only bi-bevel and bevel-up. | pfm medical |
| Shape | Angled and straight versions appear in AccessGUDID entries (for example 1.2 mm angled, 2.0 mm straight). | AccessGUDID |
| Protection | One AccessGUDID entry carries “with protection” in its name; the 2.0 mm bevel-up straight record does not. | AccessGUDID |
| Handle and reuse | Plastic handle: single-use. Aluminium handle: autoclave resterilisation after cleaning, per the manufacturer. | pfm medical |
| Sterile status | The AKTIVE 1.2 mm record is marked packaged sterile: yes; requires sterilization before use: no. The 2.0 mm record is also marked packaged sterile and single-use. | AccessGUDID |
Where it matters for labs, clinics and supply decisions
Regulatory identity
FDA’s product classification database lists code HNN as “knife, ophthalmic” under 21 CFR 886.4350, “Manual ophthalmic surgical instrument”. It is Class 1, in the Ophthalmic panel, marked 510(k) exempt, not implanted and not life-sustaining. The same entry shows “GMP Exempt: No”. FDA notes that it exempted almost all Class 1 devices from premarket notification and tells readers to confirm exemption status and limitations in 21 CFR Parts 862 to 892.
A record-checking checklist
Each item below follows from fields that appear in product records.
- Identity: does the listing show the product code HNN and the device name as “knife, ophthalmic” in AccessGUDID or FDA’s classification database?
- Single-use or reusable: does the record say “single-use device”, or does the manufacturer describe a resterilisable handle?
- Sterility: is it packaged sterile, and does the record say whether sterilization is required before use?
- Blade geometry: are width, bevel direction (up, down, bi-bevel) and straight or angled shape all stated?
- Protection and handle: does the name include “with protection”, and is the handle plastic or aluminium?
The same record-reading approach applies to related instruments such as lancets and surgical scissors, and to broader sets covered in orthopedic surgical instruments.
Common misunderstandings
- “Crescent blade” is one fixed size. Records from different manufacturers show widths from 1.2 mm to 2.6 mm.
- It is a scalpel blade number. Entries are named as crescent knives or crescent scalpels with their own width and bevel attributes, not by a scalpel blade number.
- Class 1 means no regulatory controls. FDA’s entry shows the device is 510(k) exempt but not GMP exempt.
- All crescent knives are single-use. The GMDN term is single-use, but one manufacturer describes an aluminium-handled version it states can be autoclaved after cleaning.
FAQ
What is a crescent blade?
It is an ophthalmic hand instrument with a single-edged, curved blade. AccessGUDID classes it under the GMDN term “Ophthalmic knife, single-use”.
Is a crescent knife a medical device in the United States?
Yes. FDA lists ophthalmic knives under product code HNN and 21 CFR 886.4350 as a Class 1 device that is 510(k) exempt.
What is the difference between a crescent blade and a crescent knife?
The names are used for the same kind of ophthalmic instrument. AccessGUDID entries say “Crescent Knife”, while pfm medical sells a “Crescent Scalpel”; both carry their own width and bevel attributes.
Is a crescent knife single-use?
Not always. AccessGUDID lists the GMDN term as single-use, and pfm medical states that its plastic-handled version is single-use only, while its aluminium-handled version can be resterilised in an autoclave after cleaning.
How do I look up a specific crescent knife?
Search AccessGUDID by the device name or catalog number. The record shows company, product code, size, sterile-packaging status and single-use status.
Sources
- AccessGUDID (National Library of Medicine), Crescent Knife 1.2 mm Bevel Up Angled with protection, AKTIVE SRL, checked 2026-10-30.
- AccessGUDID (National Library of Medicine), Crescent Knife 2.0 mm Bevel Up Straight, AKTIVE SRL, checked 2026-10-30.
- FDA, Product Classification, code HNN, knife, ophthalmic, checked 2026-10-30.
- pfm medical, FEATHER Crescent Scalpel, checked 2026-10-30.
