The Hessburg-Barron vacuum trephine

For close to a century, replacing a cornea began with a circle drawn freehand.

A century of freehand circles

The trephine is not recent. von Hippel was already driving a clockwork version in the 1880s, and in December 1905 Zirm performed the first successful human corneal graft. But however much the instrument improved, the cut itself remained free.

The surgeon pressed a cylindrical blade against a globe that was soft, curved and mobile, then turned. The difficulty is not cutting: it is cutting perpendicular to a surface that gives way. A slight tilt and the edges no longer matched — the graft healed with an astigmatism the patient kept for life. A technically successful graft could thus deliver a clear cornea and mediocre vision.

Suction as the answer

In 1980, Philip Hessburg and Barron presented a disposable trephine that answers that problem with suction.

A continuous 360° suction chamber grips the cornea and immobilises the globe. The surgeon is no longer fighting an eye that escapes under pressure; instrument and eye become a single solid unit. A fine reticle allows the blade to be centred on the visual axis before starting — centring stops being a matter of judgement.

Another decisive detail: the blade is carried on a spoked threaded adapter, and one full turn lowers it by exactly 0.25 mm. Depth becomes a number. The surgeon no longer judges by feel that they are at mid-stroma: they count turns. A later version would add radial marks around the chamber, so that sutures distribute symmetrically around the wound rather than by estimate.

That is what the instrument really delivers — not a prettier cut, but a reproducible one, transmissible and teachable.

What the cut did not do

It was never perfect, and it is better said than left unsaid. Work on donor globes at controlled pressure has shown that the opening obtained is consistently wider than the nominal diameter of the blade, and that the configuration of the cut varies appreciably from one trephine model to another. The geometry of the apposition is therefore not quite the one you think you are drawing, and part of post-keratoplasty astigmatism stems from that discrepancy rather than from the surgeon’s hand.

The arrival of lamellar surgery

Then corneal surgery changed its logic. DSAEK, DMEK, DALK: replace the diseased layer, not all five. Eye banks began delivering tissue pre-cut, pre-delaminated, pre-loaded. Femtosecond lasers offered profiled cuts — zigzag, mushroom, top hat — that a circular blade cannot produce, and that improve apposition and wound stability.

On paper, the instrument should have disappeared.

And yet

It has not retired. Full-thickness disease still calls for a full-thickness graft, and those indications have not gone away. Above all, where the banks do not supply prepared lamellar tissue, it is the surgeon who prepares it — dissecting, punching and trephining at the operating table, exactly as before. For a great many corneal surgeons around the world, this trephine is not a museum piece: it is this morning’s operating list.

The quieter lesson

This may be the most useful thing the instrument teaches, and it is not technical at all.

What retires an instrument is rarely a better instrument. It is a tissue bank, a supply chain, a budget. The superiority of a technique is not enough to spread it: the ecosystem that makes it possible has to exist where you operate. The Hessburg-Barron trephine survives precisely where that ecosystem is missing — which makes it less a relic than an indicator of inequalities of access to tissue.

All the more reason, before declaring a technique outdated, to specify where.

Techniques pass. The discipline that grounds the indication endures.

References

1. von Hippel A. Eine neue Methode der Hornhauttransplantation. Albrecht von Graefes Arch Ophthalmol. 1888;34:108-130.
2. Zirm E. Eine erfolgreiche totale Keratoplastik. Albrecht von Graefes Arch Ophthalmol. 1906;64:580-593.
3. Hessburg PC, Barron M. A disposable corneal trephine. Ophthalmic Surg. 1980;11(10):730-733.
4. van Rij G, Waring GO 3rd. Configuration of corneal trephine opening using five different trephines in human donor eyes. Arch Ophthalmol. 1988;106(9):1228-1233.
5. Melles GRJ, Ong TS, Ververs B, van der Wees J. Descemet membrane endothelial keratoplasty (DMEK). Cornea. 2006;25(8):987-990.
6. Steinert RF, Ignacio TS, Sarayba MA. “Top hat”-shaped penetrating keratoplasty using the femtosecond laser. Am J Ophthalmol. 2007;143(4):689-691.