A. Within the last few years, several techniques have been put forward to correct hyperopia or farsightedness. Some have merit but there is one that should be avoided like the plague.

In 1979, Yamashita,[1,2] building upon the work of Sato and the experience of Gills, experimented with closed ended incisional configurations in rabbits. He found the optimum configuration to be that of six incisions arranged in the shape of a hexagon . By varying the width of the hexagon he was able to induce an increase in the central corneal curvature proportional to the size of the hex. Encouraged by this work, Mendez applied the technique to human corneas.[3] By varying the size of the hexagon from 7.5 mm to 4.5 mm, up to 4 diopters of hyperopia could be reduced. The corneas remained fairly stable but in some cases extreme gaping of the incisions occurred with resultant marsupialization and instability as well as astigmatism. In at least one case, extreme central corneal edema with subsequent sloughing of tissue occurred necessitating a penetrating keratoplasty. Predictability is only fair and no account is taken of sex, age or corneal elasticity.

Most eye surgeons, including myself have stopped performing this operation after experience has shown it to too risky for the results obtained. I have had too many referrals of patients who have had this procedure and now need further surgery to restore vision.

Be afraid. Be very afraid. But read on.

The following is redacted (with permission from Ophthalmology Management magazine) from an article I submitted for a series on My Worst Medical Mistakes.

The Operation From Hell

When HK was first introduced, I was reluctant to do it and for good reasons, not the least of these was the circular keratotomy (CK) debacle [4] but also because the procedure violated First Principles. I predicted that isolating the central cornea in such a way would ultimately result in what can best be described as ‘flail cornea’; a corneal surface that would never stabilize given that it was bereft of any anchors and totally at the mercy of fluctuations in IOP, lid movement and atmospheric pressure. Healing, slow in the best of circumstances, would be even slower if healing ever happened at all and that marsupialization of the incisions was riding high in the list of probable outcomes. Time proved me right, but unfortunately for some 5-6 of my patients, unlike Laacoön, I was not devoured on the spot by a sea monster sent by the gods.

Nordan raised a cry publicly shortly after we had discussed it.[5-7] So given all that, why did I stoop to performing HK at all? For several reasons. First among these is a character flaw which sometimes over-rides my better judgment or intuition. That flaw sends forth a little voice which constantly whispers: “You could be wrong you know.” Some say that’s a good flaw but not in this case. Add a little hubris into the mix and combine it with the fact that the ‘crowd’ was boarding the train and that several of my friends, fellows who had stuck by me when I introduced what became known as radial keratotomy, were claiming good results. Therefore, because a significant minority of respected refractive surgeons were doing the surgery, I followed suit with a few patients. It would have been better to listen to my intuition. The upshot was that it took me almost 5 years/eye before I was finally able (with the help of Momma Nature, a modicum of luck and some surgical skills) to stabilize those corneas to the point that the patients had near-normal vision again. I say ‘near-normal’ because none were ever truly normal again.

So what lessons can be gained from this experience? Firstly and foremost — make sure that you remain a physician. Too many of our colleagues treat patients by rote. Too many treat problems in the same way time and again and with methods adopted from others ‘with more experience’ combined with the phenomena of enthusiastic presentations by “pioneers” from “eye institutes”.[8] Too many surgeons equate numbers with skill and just because they have high numbers of surgical cases assume for themselves the mantle of ‘guru’ when what they really are, are machines. Machines that — no doubt — are excellent at what they do but machines nonetheless. And machines don’t think. Many of us adopt ideas (which others slavishly follow) as if these had sprung forth from the forehead of Zeus; thereby falling into the trap of believing that we, above all others have, ‘The Answer’. I cannot count the occasions during the introduction of RK that I was approached by ophthalmologists who were only too willing to share with me ‘where I had gone wrong with RK’ and despite that they had never done a case knew ‘how to fix it’; of course they all had degrees in engineering as well.

A true physician follows First Principles. That is, basic tenants which apply to the problem at hand and which exist — and have existed — since the Dawn of Time. What First Principle(s) did I violate in this case? I knew about the CK debacle; I knew about the work of Sato and Akiyama with similar incisions;[9] and I knew from my own carefully studied experience that such incisions could be trouble. The First Principle I ignored was this: ‘Is what you are going to do materially different from that which previous physicians have tried and failed?’ The answer was an unqualified ‘no’. And yet I did HK. Why? Because I ignored another First Principle: ‘When in doubt — don’t!’ The corollary of which is: ‘There is no eraser on a knife.’ Halstead said it best when he said: ‘The only difference between a good surgeon and a bad surgeon is that the good surgeon knows when not to cut.’ My intuition was screaming at me and to my everlasting sorrow I ignored it. See that you are not overwhelmed by the same sort of arrogance. Have the courage of your convictions and most of all — think before you leap and take the patient with you.

References

1. Yamashita, T. and R. Gaster. Experimental hyperopia correction. Parts I and II. in Keratorefractive Society. 1983. Chicago: LAL Publishing. 
2. Yamashita, T. Hexagonal incision to reduce RK overcorrection. Experimental study. in Keratorefractive Society. 1984. Atlanta, GA: LAL Publishing. 
3. Mendez, A., Correcao da hipermetropia pela ceratotomia hexagonal., in Cirugia Refractive., R. Guimarares, Editor. 1987, Piramide Livro Medico Editora Ltd: Rio de Janeiro, Brazil. p. 267-279. 
4. Gills, J., Trephination in combination with radial keratotomy for myopia, in Radial Keratotomy, R. Schachar, N. Levy, and L. Schachar, Editors. 1980, LAL: Dennison, TX. 
5. Nordan, L.T. and W.A. Maxwell, Avoid both radial keratotomy with small optical zones and hexagonal keratotomy [letter]. Refract Corneal Surg, 8(4): p. 331; 1992. 
6. Nordan, L.T. and W.A. Maxwell, Refractive surgery and informed consent. Radial keratotomy with small optical zone hexagonal keratotomy [letter]. J Cataract Refract Surg, 18(4): p. 420-421; 1992. 
7. Nordan, L.T. and W.A. Maxwell, Hexagonal keratotomy [letter; comment]. Refract Corneal Surg, 9(3): p. 228-229; 1993. 
8. Waring, G.O., The Hamburger Institute. J Refract Corneal Surg, 10: p. 495-497; 1994. 
9. Akiyama, K., Posterior corneal incision for hyperopia in rabbits. Nippon Ganka Gakkai Zasshi, 56: p. 11-42; 1952.