Ophthalmic Cannula Types and Gauges: Hydrodissection to DALK

Instrument guides

Ophthalmic Cannula Types: Hydrodissection, Irrigation, LASIK, Lacrimal and More

Which eye surgery cannula does which job, from hydrodissection and irrigation to LASIK, DALK, lacrimal and anesthesia, with a gauge chart and the patterns we make.

110 cannulas14 to 30 gaugeReusable steel

Ophthalmic cannulas are fine, blunt tubes that deliver or remove fluid, air or anesthetic inside and around the eye. Choose by job first: hydrodissection cannulas separate the lens layers, irrigating and aspirating cannulas maintain and clean the chamber, chamber maintainers infuse continuously, LASIK cannulas irrigate under the flap, DALK cannulas inject air into the stroma, lacrimal cannulas irrigate the tear ducts, and anesthesia cannulas place the block. Then choose the gauge: the higher the gauge, the finer the tube.

How did these cannulas come about?

Modern cataract surgery began with Charles Kelman's 1967 paper on phacoemulsification, which Ophthalmology Management recounts. Small incision surgery needed fine cannulas to irrigate, aspirate and separate the lens through openings of a few millimetres, and many patterns carry the names of the surgeons who refined each step. For corneal transplants, the "big bubble" technique introduced by Anwar and Teichmann in 2002 injects air into the deep stroma to separate it from Descemet's membrane, as a CRST Europe review explains. That is the job of our DALK air injection cannulas.

Which cannula does which job?

Job	Patterns	Gauges
Hydrodissection and hydrodelineation	Chang, Akahoshi, Corydon, Feaster, Barrett, Blumenthal	25 to 30
Irrigation	Binkhorst, Bishop-Harmon, Bracken, Anis vectus, Drof infusion	19 to 27
Aspiration	Anis cortex aspirating, Fish, Brierly capsulorhexis	21 to 26
Chamber maintainers	Blumenthal, threaded or smooth, Dahan-Blumenthal, DSAEK maintainer	20 to 25
Capsule and nucleus	cystotome, Drews cystotome, Dahan nucleus prolapsing, Alfonso-McIntyre spoon, Drews polisher	22 to 30
LASIK	Buratto, Banaji, Brierly, Dishler, flip and float, Alio	23 to 30
DALK air injection	Fogla, DALK, air injection, 5 to 12 mm from bend	19 to 30
Lacrimal	Bailey, Burnstein, Fasanella	23 to 30
Anesthesia	Atkinson retrobulbar, Corbin sub-Tenon, Connor	19 to 30
Retina	Charles flute backflush	20, 23, 25
Periorbital fat	Fox fat injection, left or right	14

What does the gauge mean?

Gauge	Nominal outer diameter
19	1.07 mm
20	0.91 mm
23	0.64 mm
25	0.51 mm
27	0.41 mm
30	0.31 mm

A higher gauge number means a finer cannula. Values are the nominal outer diameters from the standard needle gauge chart. Fine gauges pass through small incisions and give a gentle stream. Coarser gauges move more fluid.

How should reusable cannulas be cleaned?

Flush every cannula with sterile water straight after use, then flush with air to dry the lumen. Fine lumens block easily and residue inside a lumen is invisible. Inspect tips under magnification for burrs. Never leave instruments in saline, because it causes corrosion. Our instrument care guide gives the full routine, and the CDC guidance on cleaning instruments before sterilization explains why cleaning comes before the autoclave.

Frequently asked questions

What is a hydrodissection cannula?

A fine, often flattened or bent cannula that injects fluid under the anterior capsule to free the lens from its capsule during cataract surgery.

Which gauge is finer, 25 or 30?

30 gauge is finer. The higher the gauge number, the smaller the diameter.

What is an anterior chamber maintainer?

A cannula fixed in a small incision that infuses fluid continuously to keep the anterior chamber formed.

Are reusable ophthalmic cannulas autoclavable?

Ours are. Flush and dry every lumen before the cycle.

Order ophthalmic cannulas

See the full ophthalmic cannula range. For a set for a hospital, a clinic or a distributor, send us your list and we will send you a quote.