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This page describes products and general use; it is not medical advice.
A lacrimal probe (spelled “lachrymal probe” in U.S. federal regulation) is a thin, handheld, non-powered ophthalmic instrument used to examine the nasolacrimal (tear drainage) system. The best-known example is the Bowman probe. This page covers the instrument itself: its size groups, length, how it differs from a cannula and how the FDA classifies it.
Who uses it: oculoplastic and ophthalmic surgeons and their teams; clinic and surgery-center staff who stock and reprocess instrument trays; students learning ophthalmic instruments.
What is a lacrimal probe?
A lacrimal probe is a manual ophthalmic surgical instrument for the tear drainage passages. The University of Iowa Department of Ophthalmology and Visual Sciences describes Bowman probes as instruments that “may be used to detect obstruction or laceration of the nasolacrimal system” and that are “also used to lyse stenotic membranes within the nasolacrimal system” (EyeRounds, page last updated 14 March 2017).
How is it classified by the FDA?
In 21 CFR 886.4350, the FDA defines a manual ophthalmic surgical instrument as “a nonpowered, handheld device intended to aid or perform ophthalmic surgical procedures.” The regulation lists “lachrymal probe” and “ophthalmic cannula” as separate named examples of this generic device type. It is Class I (general controls) and exempt from premarket notification (510(k)) under subpart E of part 807, subject to the limitations in 21 CFR 886.9 (Cornell LII copy of the eCFR).
Two practical points follow from the regulation text: a probe and a cannula are listed as different devices, and the exemption is subject to the limits in 886.9. For how device classes work in general, see what is a medical device and the FDA 510(k) and De Novo submission guide.
Types and variants
| Variant | Detail | Key difference |
|---|---|---|
| Bowman probe | Supplied in size groups 0000-000, 00-0, 1-2, 3-4, 5-6 and 7-8, 5.75 inches long (EyeRounds) | Used to detect obstruction or lyse stenotic membranes in the nasolacrimal system |
| Lachrymal probe (generic type) | Named in 21 CFR 886.4350 as a manual ophthalmic surgical instrument | Regulatory name for the device type; Class I, 510(k)-exempt |
| Ophthalmic cannula | Named separately from the lachrymal probe in 21 CFR 886.4350 | Listed as a distinct device type, not a probe size |
| Probe with attached stent | EyeWiki (American Academy of Ophthalmology) notes a probe with a stent swedged to one end exists | Combines probing with leaving a stent in place |
Bowman probe
The Bowman probe is the variant most searchers mean. The EyeRounds oculoplastic tray page lists it as one product in six size groupings at 5.75 inches.
Lacrimal cannula
The eCFR lists the ophthalmic cannula as its own device type, separate from the lachrymal probe.
Sizes that matter
| Specification | Value | Source |
|---|---|---|
| Bowman size groupings | 0000-000, 00-0, 1-2, 3-4, 5-6, 7-8 | EyeRounds |
| Bowman length | 5.75 inches | EyeRounds |
| Probe diameter range EyeWiki describes for nasolacrimal duct probing | 0.70 to 1.10 mm | EyeWiki, Nasolacrimal Duct Obstruction, Congenital |
The size numbers (0000 through 8) are catalogue labels. No published conversion from each label to millimetres is cited on this page, so do not assume one. The 0.70 to 1.10 mm figure is the clinical range EyeWiki describes for probing, not a mapping of the numbered sizes.
How to choose
The facts that matter when specifying a probe are: the size grouping label, the 5.75 inch length for Bowman probes, and the regulatory name “lachrymal probe” (21 CFR 886.4350).
Safe use and handling basics
A lacrimal probe is a surgical instrument used by trained clinicians. This page gives product information only. For sterile versus non-sterile instrument supply, see sterile vs non-sterile purchasing; for general instrument families see medical forceps types and the ophthalmology surgery center supply checklist.
Common mistakes
- Reading Bowman size numbers as millimetres. They are labels; the 0.70 to 1.10 mm range is a separate clinical description.
- Treating a probe and a cannula as the same device. 21 CFR 886.4350 names them separately.
- Assuming a Class I, 510(k)-exempt device needs no compliance attention. The exemption is subject to the limitations in 21 CFR 886.9 and general controls still apply.
FAQ
What is a lacrimal probe used for?
To detect obstruction or laceration of the nasolacrimal system and to lyse stenotic membranes within it, according to the University of Iowa EyeRounds description of Bowman probes.
What is a Bowman probe?
A lacrimal probe supplied in size groupings 0000-000 through 7-8, 5.75 inches long, per EyeRounds.
What are lacrimal probe sizes?
Bowman probes come in six numbered groupings (0000-000, 00-0, 1-2, 3-4, 5-6, 7-8). EyeWiki describes probes of 0.70 to 1.10 mm diameter for nasolacrimal duct probing. The numbered sizes are not mapped to millimetres in these sources.
Is a lacrimal probe the same as a lacrimal cannula?
No. The FDA regulation lists the lachrymal probe and the ophthalmic cannula as separate named devices under 21 CFR 886.4350.
Is a lacrimal probe an FDA-regulated device?
Yes. It falls under 21 CFR 886.4350 as a Class I, 510(k)-exempt manual ophthalmic surgical instrument, subject to the limitations in 21 CFR 886.9.
Sources
- University of Iowa EyeRounds, Bowman Probes (Sizes 0000-000 to 7-8), 5.75 inch, checked 2026-10-31.
- EyeWiki (American Academy of Ophthalmology), Nasolacrimal Duct Obstruction, Congenital, checked 2026-10-31.
- 21 CFR 886.4350, Manual ophthalmic surgical instrument, Cornell LII copy of the eCFR, checked 2026-10-31.
