HISTORY OF REFRACTIVE SURGERY by Rivista Sfogliabile

Lucio Buratto Richard Packard

HISTORY OF

REFRACTIVE SURGERY

Fabiano Editore

Lucio Buratto, Richard Packard

HISTORY OF REFRACTIVE SURGERY Jorge L. Alió, Georges Baïkoff, Carmen Barraquer Coll, Rubens Belfort Jr., Perry S. Binder, Marcus Blum, Angela Bocchese Nosé, Steve Brint, Camille Budo, Lucio Buratto, Massimo Camellin, Umberto Camellin, John F. Doane, Irina Fedorova, Luisa Frizziero, Jérôme Galand, Ronald R. Krueger, Jorg Krumeich, Marguerite McDonald, Ricardo Menon Nosé, Maya Müller, Tobias Neuhann, Walton Nosé, Robert H. Osher, Richard Packard, Ioannis Pallikaris, Yaron S. Rabinowitz, Theo Seiler, Stephen G. Slade, Yuri Takhtaev, Ibrahim Toprak, Bennett Walton, Roberto Zaldivar

Fabiano Gruppo Editoriale

Publisher: FGE S.r.l. Fabiano Gruppo Editoriale Field office: Regione Rivelle 7/F - 14050 Moasca AT, Italy Editorial office: Via Petitti 16, 20149 Milano, Italy e-mail: info@fgeditore.it - Tel. +39 0141 1706694 The Authors and the Editor decline any responsability for any errors in the text. All rights reserved. Reproduction of this book - total or partial - is strictly forbidden. Printed in: June 2020

To my delightfully grandson Yuto. With the hope that whatever profession he follows it will be with enthusiasm, integrity and enjoyment. Grandad Lucio

I dedicate this book to my wife Fiona for her enduring tolerance of the time I have taken when editing and writing this book which has enabled me to gain a privileged insight into the minds of all the extraordinary people who have contributed to the history and evolution of refractive surgery. Richard Packard

Index CHAPTER 1

THE LAW OF THICKNESSES .............................................................................7

Carmen Barraquer Coll

CHAPTER 2

Jorg Krumeich

CHAPTER 3

Richard Packard

CHAPTER 4

Irina Fedorova

CHAPTER 5 CHAPTER 6

EPIKERATOPHAKIA TECHNIQUE AND KERATOCONUS ........................................................................................ 21 INCISIONAL REFRACTIVE CORRECTION ............................................. 31 RADIAL KERATOTOMY AND PHAKIC IOLS ......................................... 51 THE 25TH ANNIVERSARY OF EXCIMER LASERS IN REFRACTIVE SURGERY: HISTORICAL REVIEW .......... 61

Ronald R. Krueger, Yaron S. Rabinowitz, Perry S. Binder

THE HISTORY OF REFRACTIVE SURGERY WITH 32 YEARS OF LASER VISION CORRECTION ............................ 85

Marguerite McDonald

CHAPTER 7

Lucio Buratto

CHAPTER 8

Steve Brint

CHAPTER 9

FROM FROZEN KERATOMILEUSIS TO FEMTO LASIK .............................................................................................. 101 MY HISTORY OF REFRACTIVE SURGERY IN NEW ORLEANS .... 165 THE HISTORY OF REFRACTIVE SURGERY IN THE UNITED STATES ................................................................................ 169

John F. Doane, Bennett Walton, Stephen G. Slade

CHAPTER 10

THE DEVELOPMENT OF LASIK AND LASER REFRACTIVE SURGERY ....................................................... 191

Ioannis Pallikaris

CHAPTER 11

HISTORY OF LASEK AND EPI-LASEK ..................................................... 211 Massimo Camellin, Umberto Camellin, Luisa Frizziero

CHAPTER 12

THE HISTORY OF FEMTOSECOND LASER ASSISTED LASIK (FS-LASIK) ......................................................... 217

Jorge L. Alió, Ibrahim Toprak

CHAPTER 13

HISTORY AND EVOLUTION OF SMILE SURGERY ......................................................................................... 245

Marcus Blum

CHAPTER 14

Yuri Takhtaev

CHAPTER 15

Robert H. Osher

HISTORY OF REFRACTIVE SURGERY IN RUSSIA .............................. 253 A CAREER OF REFRACTIVE CATARACT SURGERY............................ 277

CHAPTER 16

THE HISTORY AND EVOLUTION OF LENS EXTRACTION FOR REFRACTIVE PURPOSES ..................................... 293

Richard Packard

CHAPTER 17

Roberto Zaldivar

CHAPTER 18

Georges Baïkoff

CHAPTER 19

IRIS FIXATED IOL's ......................................................................................... 357 Camille Budo, Jérôme Galand

CHAPTER 20

Tobias Neuhann

HISTORY AND EVOLUTION OF ICL ........................................................ 323 ANGLE SUPPORTED ANTERIOR CHAMBER IMPLANTS............... 341

THE INTRAOCULAR CONTACT LENS (ICL) ........................................ 385

CHAPTER 21

THE "MYOPIA OPERATION" OR PREMATURE DISSEMINATION 100 YEARS AGO................................ 399

Maya Müller MD, Theo Seiler MD, PhD

CHAPTER 22

CORNEAL RINGS ............................................................................................... 405 Ricardo Menon Nosé, Angela Bocchese Nosé, Walton Nosé, Rubens Belfort Jr.

1 The law of thicknesses

The fundamentals of lamellar refractive surgery “Keratomileusis and keratophakia” Carmen Barraquer Coll

Lamellar refractive corneal techniques are now the most commonly performed lifestyle elective surgical procedures in the world, They have good results, with a very low complication rate and give great satisfaction for patients and doctors. How did they come to be in our ophthalmological world? Let’s go back 70 years to when it all began, in the most classical scientific way…. José Ignacio Barraquer Moner, 26 years old and having obtained his medical degree, was at the beginning of his ophthalmological practice in 1942. Following the experience of Filatov he was doing penetrating corneal grafts with cadaver material1. The graft buttons at that time were 5.0 or 6.0 mm in diameter. It was found that in cases of advanced keratoconus that the postoperative cornea had a high vault which was partly due to the adherence of the graft to the apex of the cone This suggested to Barraquer that it would be advisable to perform keratoplasty operations with larger graft dimensions. The aim was to obtain the complete normalization of the corneal curvature. Castroviejo in contemporary publications, insisted particularly on this2. On the other hand, Barraquer also found that it was important to match the grafts with corneal tissue of normal thickness on the recipient cornea. Based on this, he decided to correct the curvature and the thickness of the cornea with a superficial keratoplasty operation as a primary procedure. (Fig. 1) The postoperative course of this surgery resulted in the cornea remaining completely transparent, the vault had decreased and gave good visual acuity, with correction of only small amounts of the refractive ametropia 3. In order to simplify the postoperative course even more, Barraquer decided to use an autoplastic graft in all keratoconus cases in which the corneal transparency was not affected, in order to avoid the risks of a procedure with a homoplastic graft. A peripheral trephination with an 11.0mm trephine was made at a depth of half the corneal thickness. Then a second trephination concentric to the first was made with a 10.0mm trephine at the same depth. The ring of tissue between the two trephinations was resected followed by a superficial dissection of the central corneal layers to obtain a complete superficial keratoplasty. This graft was sutured in place with 12 or 16 sutures, An anterior chamber paracentesis had been performed prior to this4. (Fig. 2 ). The results were excellent, and so he used this technique also in the normal corneas of patients with anisometropia of about 10.0 diopters of myopia. Having corrected myopia by flattening the corneal radius Barraquer wanted also, to treat hyperme7

HISTORY OF REFRACTIVE SURGERY

1- Corneal opacity by aqueous infiltration VA: LP.

4- Postop: Residual leucoma VA: 0.5.

2- Acute Keratoconus.

5- Normalization of corneal curvature.

3- Keratography: high astigmatism and epithelial edema turn the image blurry and irregular

6- Postoperative keratography

Figure 1. From Barraquer M Jose I. “The non-penetrating corneal graft in the treatment of Keratoconus”, Estudios e informaciones Oftalmológicas 1951 Vol 3 P.15

Ch ap ter 1 The l aw o f t hi ck n esses

Figure 2. Original schema of the autoplastic surgical technique to decrease the dioptric power on the cornea A) Double trephination of 11 and 10mm diameter. B) Resection of the ring of tissue. C) Lamellar dissection of 10mm of the central corneal tissue. D) Replacement of the graft and suture at the 11 mm border with the edge to edge suture. From Barraquer M José I. “Queratoplastia Refractiva”. Estudios e informaciones Oftalmológicas 1949 Vol 2 pag 6

tropia which would require increasing the corneal curvature. In order to do this, he proposed inserting a lens, made of a high refractive index plastic in between the lamellar corneal dissection and a homoplastic graft of normal thickness over it The experience gained with his “lamellar keratoplasty” operations, underscored the logic of modifying the ocular refraction by working on the cornea which is the eye’s most accessible and powerful refractive structure. He published his ideas in 1949 in a paper called “Queratoplastia Refractiva”. translating it to French, English and German4. (Fig. 3-4) Barraquer continued his research, however having no technical method to modify the shape of the lamellar graft recipient bed stromal posterior layers, he decided to modify the shape of the graft itself. The initial trials were carried out on donor lamellar grafts in corneas with superficial leucomas and ametropia. Here the shape and curvature of the graft had been modified with metallic burrs, diamond burrs, emery or carborundum. Although the results were encouraging, they lacked the necessary precision and he thus encountered unexpected refractive results. Eascott’s 5 discoveries of the viability of frozen corneas and of glycerine as protector of the transpa9

HISTORY OF REFRACTIVE SURGERY

Figure 3, 4. The article of José I.Barraquer M.(original) published in 1949 On the left side the front page – on the right, page number 6 of the article

rency of frozen grafts at -79ºC in 1954, opened a new frontier to Barraquer. He carried out experiments in donor autoplastic and homoplastic corneas in dogs, pigs, rabbits and guinea pigs and was able to prove that it worked. After several trials and failures, he achieved 100% corneal transparency in a group of rabbit lamellar grafts of 6.0mm diameter and 300µ thickness which had been frozen for 5 minutes at -79ºC.. The next step was to modify the curvature of the stromal side of the frozen cornea as in the manufacturing of contact lenses. He then had to prove that after thawing the modified tissue maintained transparency and viability. In 1958 Barraquer bought a watchmaker’s lathe modified by Remdix to try to do this. He encountered multiple difficulties in maintaining the frozen cornea in place on the lathe during graft reshaping. After many trials he overcame the difficulties by constructing a lathe platen with a chamber for carbon dioxide snow and a plastic corneal holder. This was fixed to the lathe platen by means of a bayonet device. Finally, these experiments demonstrated that the modified frozen corneal tissue retained its transparency and viability. There was also a much more regular stromal surface after lathing than was possible with the manual or other methods utilised up until then6. By this method Barraquer was able to modify experimentally the spherical power of the corneal lamellar buttons. Having proved the viability of the method, he bought a Levin spherical lathe which had higher precision. He thus began to lathe in the frozen state modified lamellar grafts for use in patients7. The grafts had been obtained manually by dissection. In rabbit experiments he also began to insert intracorneal lenticles of corneal tissue to modify the refraction8. 10

Ch ap ter 1 The l aw o f t hi ck n esses

In 1961 he presented the results of the first 20 cases which showed perfect transparency and in some cases satisfactory refractive results; thus in myopia the results were good, but in hyperopia were almost nil7. ( Fig. 5) “ Up to this date (Nov 1960) we have available 20 cases of patients with a follow up of more than one year on whom the operation was performed with lamellar grafts cut at the lathe. In 19 cases the transparency of the graft was perfect. Average postoperative astigmatism has been 2.0 diopters 6 cases have remained without defects of spheric refraction 3 patients are myopic with 1.8 diopters on the average 7 patients are hypermetropic with 5.2 diopters on the average In 4 cases the slight density of the corneal opacities made it possible to determine the preoperative refraction and we used grafts with refractive value tending to correct the said ametropia Case

Preoper refract

Graft

Postoper refract.

Vision

I -

6.50 (-4.00 x 105º)

- 8.50

-1.50 (-2.50 x 115º)

20/50

II -

10.00 (-5.00 x 5º)

- 11.00

-1.50 (-0.50 x 0º)

20/40

III +

11.00 (-2.00 x 50º)

+12.00

+10.00 (-2.00 x 20º)

20/30

+12.00 (-2.00 x 170º)

+12.00

+11.00 (-0.75 x 20º)

amblyopic

As can be seen appreciable corrections were obtained in cases of myopia, but not so in cases of hypermetropia because of aphakia. This fact is in contradiction with the tendency to myopization which is presented by grafts cut by other techniques. Therefore it should be the subject of further investigations In one case in which it was not possible to determine refraction, either subjectively or objectively, but in which the ophthalmometer indicated a corneal value of 52 diopters, a -6.0 graft was used and finally a cornea of 46.00 / 47.50 and a postoperative refraction of +6.00(-1.50 x 30º) were obtained Once 0.8 20/25 4 times 0.62 20/30 2 times..............................0.5 20/40 4 times 0.4 20/50 2 times..............................0.3 20/60 2 times 0.1 20/200 Once..................................P.L Opaque The other 4 patients were either amblyopic or they presented senile cataract for which a planed operation was to be performed” Figure 5. Copy or extract from reference 7 - Barraquer J.I: Queratoplastia and Keratoplasty. Arch. Soc.Oftal.Optom, Vol 3, Nº 3: p180 (1961)

HISTORY OF REFRACTIVE SURGERY

This results which Barraquer felt was paradoxical, encouraged him to try to clarify the reason for the difference between a negative and a positive graft. He did this with a series of experiments on rabbit corneas, to try to understand why the behavior of the cornea alters when the thickness is changed. He conjectured 7 different corneal modifications both on the surface and intrastromally and carried out 17 different operations. He published the results in 19649. (Fig. 6 to 12)

1- PRISMATIC AUTOKERATOPLASTY

Figure 6. Prismatic autokeratoplasty and rotation of the graft 180ยบ: A-Marking and resection B-Rotation of the graft C-Result: Steepening of the corneal surface at the thick border and flattening at the thin border

2- TRANSPOSITION

Figure 7. Autokeratoplasty by transposition, making one thick graft and one thin graft: A-Marking and resection B-Trasposition of the grafts C-Result: Steepening of the anterior corneal curvature in the thick graft; flattening of corneal curvature in the thin graft

3- LAMELLAR KERATOPLASTY WITH PARALLEL FACES GRAFTS:

Figure 8/1. Same thickness graft ( Fig 5-I) A-Marking and resection B-The graft in the bed with the same thickness C-Result: No change in preoperative corneal radius

Ch ap ter 1 The l aw o f t hi ck n esses

Figure 8/2. Lamellar keratoplasty with a thinner graft (Fig 5 -II) A-Resection of the graft B- Thin graft in the corneal bed C-Result: Flattening of the anterior corneal radius

Figure 8/3. Lamellar keratoplasty with a thicker graft: (Fig 5 -III) A-Resection of the graft B- Thicker graft than the recipient bed in place C-Result: Steepening of anterior corneal radius

4- LAMELLAR KERATOPLASTY WITH A NEGATIVE GRAFT:

Figure 9/1. Lamellar keratoplasty with a thinner border than the recipient bed. A-Resection and graft B-Graft in the recipient bed C-Result: Increased flattening than desired

Figure 9/2. Lamellar keratoplasty with same thickness in the border than the recipient bed. A-Resection and graft B-Graft in the recipient bed C-Result: Flattening of the anterior corneal surface according to the power of the graft

HISTORY OF REFRACTIVE SURGERY

Figure 9/3. Lamellar keratoplasty with a thicker border graft than the recipient bed. A-Resection and graft B-Graft in the recipient bed C-Result: Steepening of the anterior corneal surface

5- LAMELLAR KERATOPLASTY WITH A POSITIVE GRAFT:

Figure 10/1. Lamellar keratoplasty with a positive graft: thinner than the recipient bed A-Resection and graft B-Graft in the recipient bed C-Result: Flattening of the anterior corneal surface

Figure 10/2. Lamellar keratoplasty with a positive graft: with same thickness in the border than the recipient bed. A-Resection and graft B-Graft in the recipient bed C-Result: Steepening of the anterior corneal surface according to the power of the graft

Figure 10/3. Lamellar keratoplasty with a positive graft with thicker border than the recipient bed A-Resection and graft B-Graft in the recipient bed C-Result: Increased steepening of the anterior surface than desired

Ch ap ter 1 The l aw o f t hi ck n esses

6- INTRAESTROMAL INSERTION

Figure 11/1. Intrastromal insertion of lenticle with parallel faces A-Incision and lenticle B-Lenticle included C-Result: Steepening of the anterior corneal surface

Figure 11/2. Intrastromal insertion of a negative lenticle A- Incision and lenticle B- Lenticle included C- Result: Flattening of the anterior central portion of the cornea

Figure 11/3. Intrastromal insertion of a positive lenticle ) A- Incision and lenticle B- Lenticle included C- Result: Steepening of the anterior corneal surface

HISTORY OF REFRACTIVE SURGERY

7- INSERTIONS AND PERIPHERAL RESECTIONS

Figure 12/1. Insertion of a corneal ring. A- Incision and ring of tissue B- Ring inserted in the incision C- Result: Flattening of the anterior corneal surface inside the ring area

Figure 12/2. Intrastromal insertion of a corneal tissue ring A- Incision and ring of tissue B- Ring inserted intrastromal C- Flattening of anterior corneal surface

Figure 12/3. Resection of a peripheral corneal tissue ring A- Incisions B- Resection C- Steepening of the anterior corneal surface

Ch ap ter 1 The l aw o f t hi ck n esses

These experimental modifications in the thickness of the cornea, demonstrated a clear relation between variations in corneal thickness and the radius of curvature of the optical surfaces. This relationship already demonstrated, allowed him to state that the norm that governs the relationship between thickness and curvature, may be explained by a general law “ The Law of Thicknesses” and according to it10-11: The anterior surface of the cornea becomes steeper by adding tissue to its optical center or subtracting it from the corneal periphery. It becomes flatter by subtracting tissue from its optical center or adding tissue at the periphery of the corneal vertex10-11. (Fig. 13)

Figure 13. The Law of Thicknesses A-Thickness increase at the center B-Thickness decrease at the center C-Decrease in the peripheral thickness D-Increase in the peripheral thickness. From the book Barraquer J.I: “Queratomileusis y Queratofaquia” 1980; p 72 Fig II-37

The variation of curvature of the optical surfaces in relation to the changes in corneal thickness, is more accentuated in a smaller diameter of the graft and less with an increase in its diameter. To improve the stromal recipient surface in autoplastic grafts, he developed in 1963 “ The microkeratome”, the first prototype was handmade by him, with pneumatic rings, a surgical tonometer, flattening lenses to measure the diameter of the resection and a fenestrated spatula to hold the cornea12. (Fig 14-15) 17

HISTORY OF REFRACTIVE SURGERY

Figure 14. The Microkeratome - First Prototype

Figure 15. The fenestrated spatula to hold the cornea

Professor John Charamis from Athens, suggested the name “Keratosmileusis” from Keratos = cornea and Smileusis = sculpting, for the autoplastic refractive procedures. However nowadays due to phonetics it has become keratomileusis The name “Keratophakia” was Barraquer’s idea, coming from the Greek Keratos = cornea and Facos = Lens : insertion of an intrastromal lens into the cornea. Finally he published his 40 years of research, surgical techniques, and instruments in two books: “ Queratomileusis y Queratofaquia” in 198013 and “ Cirugía Refractiva de la Córnea” in 198914. Nowadays, all the “Refractive keratoplastic” techniques, (as he called it), developed by the ophthalmological universe: 18

Ch ap ter 1 The l aw o f t hi ck n esses

■ Myopic

Keratomileusis Keratomileusis ■ Keratophakia ■ Epikeratophakia ■ Planar Keratomileusis or BKS ( Barraquer, Krumeich, Swinger) ■ In Situ Keratomileusis ■ Photorefractive Keratomileusis (PRK) ■ Laser assisted Keratomileusis (LASIK) ■ Corneal Inlays ■ Corneal Rings ■ Intrastromal Keratomileusis (SMILE) No matter the name given in modern times, are founded in a general law “The Law of Thicknesses” ■ Hyperopic

2 Epikeratophakia technique and keratoconus Jorg Krumeich INTRODUCTION In the late 1970s in New Orleans, Ted Werblin (Fig. 1), Herbert Kaufmann (Fig. 2), and Marguerite McDonald (Fig. 3) experimented with keratomileusis which had been described by José Barraquer (fig. 4). They found that heterologous corneal disks were overgrown by the reci-

Figure 1. Ted Werblin Inventor of Epikeratophakia

Figure 2. Herbert Kaufman Co-inventor of Epikeratophakia

Figure 3. Marguerite McDonald Co-inventor of Epikeratophakia

Figure 4. José Barraquer Father of all refractive procedures

pient epithelium. Suturing of corneal disks treated at the edges for insertion, called epikeratophakia (epi) or epikeratoplasty, was mainly used to treat keratoconus as well as high myopias and aphakias1,2. The procedure had been used to treat keratoconus in a nationwide study. The aim was to flatten the keratoconic cornea with a donor cornea and fixate it in the flattened position with single sutures. The published result produced a flattening of the corneal cone which averaged 9.26 diopters3,4. Owing to a failure to reproduce similar refractive results, which was mainly related to the freezing and especially the thawing of the corneal disks, we – authors Jörg H. Krumeich (fig. 5) and 21

HISTORY OF REFRACTIVE SURGERY

Casimir Swinger – developed the BKS-Set (Barraquer-Krumeich-Swinger-Set, fig. 6). This allowed for refractive cuts to be made with the microkeratome over refractive dies (fig. 7) fixed in the anterior chamber bench. The corneal slices were first cut surface-parallel in the range of 350 μm with the epithelium down on a die of each intended refraction (fig. 8, 9). With a second microkeratome cut, the refraction was transmitted to the donor button5.

Figure 5. Jörg H. Krumeich inventor of nonfreeze and refractive epi

Figure 6. Barraquer-Krumeich-Swinger Set (BKS-Set)

Figure 7. Refractive dies – left: hyperopic die base for cutting the outer circumference, right: convex die to correct myopic refraction

Ch ap ter 2 Epikerat ophak i a t ec hn i q u e an d ker at o c o n u s

Figure 8. Original non-freeze-technique microkeratome including anterior chamber bench and dies

Figure 9. Microkeratome on refractive bench

Spherical corrections between -15 and -3 and hyperopias between 3 and 12 diopters were possible. The extent of the correction certainly depended on the outgoing radius of the cornea. The flattest radius aimed at was 35 diopters, with 49 diopters the steepest to be treated. We used the epi procedure to correct high ametropia and aphakia but mainly to treat keratoconus 2,6,7. At the same time, the excimer laser to treat refractive corrections appeared on the market, and the possibilities of the BKS-Set no longer seemed to be of primary interest because keratoconus it was initially thought could be treated with an excimer laser. The nonfreeze BKS-cut epikeratophakia used in keratoconus, however, turned out to be a treatment option because the radii of the nonfreeze lenticules remained unchanged, and many patients required the same procedure for their other eye. At that time, penetrating keratoplasty was the standard treatment for keratoconus, although Anwar had published his technique for performing deep lamellar keratoplasty (DALK) for keratoconus in 19748. The benefits of the epis over the PKP were non-recurrence of the cone, the ability to save the patient’s own cornea and the absence of vision-endangering complications. We observed no immune reaction, and in every case, the BKS-cut lenticules halted progression of the keratoconus 3.

CURRENT PROCEDURE AND INDICATIONS To determine if an epi application was possible, the recipient’s pachymetry in the 6-mm zone around the optical axis should be more than 400 µm. The keratoconus created steepening should be 57 diopters at most. 23

HISTORY OF REFRACTIVE SURGERY

The main indication is now keratoconus stages I and II according to the Krumeich classification (Table 1)3,9. stage stage

stage

characteristics eccentric steepening induced myopia and/or astigmatism of

k-reading

≤ 5.0 D

≤ 48.00 D vogt's lines, typical topography induced myopia and/or astigmatism between 5.00 and 8.00 D k-reading ≤ 53.00 D pachymetry ≥ 400 µ m Induced myopia and/or astigmatism between 8.01 and 10.00 D k-reading > 53.00 D pachymetry 200 to 400 µ m refraction not measurable

stage

k-reading

> 55.00 D

central scars pachymetry

≤ 200 µ m

stage is determined if one of the characteristics applies.

corneal thickness is the thinnest measured spot of the cornea.

Table 1. Keratoconus classification

The original donor cut with the microkeratome is made with the lenticle held in the upside-down position. We now use either the CTS or GTS anterior chamber bench to fixate the donor button at a pressure of 22 mmHg. This bench simulates the conditions present in the cornea in a living eye. Therefore, the donor lenticule is fixated with an infusion of BSS, with a physiological pressure of about 20 mmHg subcorneally. The cutting of the donor lenticule thickness is performed with an excimer laser in slices to achieve a button with a central thickness of 350 µm with a rim thinned to approximately 250 µm. The actual thickness of the lenticule is measured with an OCT after every tissue removal. The donor button is reversed to its original orientation with the epithelium up and its center is marked with trypan blue. The non-IOP elevating suction ring is centered, and a suction of 800 millibar is applied. An 8-mm Merocel sponge is drenched with 20% C2H5OH for 120 seconds. Next, the corneal trephine is cut to a depth of 350 µm for the reception of the donor button (f ig. 10). Then the cut is undermined at the periphery with a bevel-down blade. The undermining cut should be approximately half a millimeter circularly from the cut. Next, the epithelium is removed from Bowman’s membrane, and the 8-mm button is placed provisionally and sutured with 4 single bites. Then, the first of the double running sutures is inserted to create a round keratoscopic image. Then the second DRA-suture is placed burying the peripheral rim of the button (f ig. 11). Only antibiotic drops are administered, and ointment is not recommended. 24

Ch ap ter 2 Epikerat ophak i a t ec hn i q u e an d ker at o c o n u s

Figure 10. 8 mm trephination after epithelium removal

Figure 11. Excimer laser-processed 8mm epi button fixated with a double running antitorque suture

CONTRAINDICATIONS Contraindications include central scars as well as incipient descemetoceles and previous refractive surgeries. With regard to crosslinking (CXL) of preoperated corneas, a reliable statement cannot be made insofar as there are no reports on nonfreeze epis on CXL-preoperated conic eyes. 25

HISTORY OF REFRACTIVE SURGERY

DEFINITION OF THE CURRENT PROCEDURE – STEP-BY-STEP In terms of obtaining the surface-parallel slice, the present method is similar to that described above with the microkeratome on the refractive bench. The disk has a diameter of 8 mm and is then cut refractively with the excimer laser on the parenchymal side as the mirror image if a refraction is to be cut in. After removal of the recipient epithelium with 20% C2H5OH, a 350-μm-deep, 8-mm pupil centered trephine cut is placed, and the processed disk is sewn in. This is done first with 4 individual sutures and then fixed with the double-running antitorque suture. The t thickness of the central part of the disk after the excimer treatment should not be less than 280 μm in thickness. This is because cones of more than 57 diopters can lead to a secondary cone in the disk. On the other hand, a slice with a thickness of 350 μm appears to be the upper limit for achieving a visual acuity of 0.8. The procedure has been used since approximately 2003 in this form, and 108 operations were performed during this time. The application of epikeratophakia is similar to that of deep lamellar keratoplasty in the presence of stage III keratoconus. The refractive correction, the advantages of reversibility, the exclusion of vision-reducing complications, and the higher cost of the epi due to the need for an excimer laser contrast must be considered when comparing epikeratophakia with DALK, with a higher operative risk but somewhat better visual acuity.

PREDICTABILITY OF THE RESULTS Epithelialization takes place in 5 days, with a low-compression eye bandage being worn until complete epithelization is achieved. Medication in the first 4 weeks is steroid eye drops 4 times daily, and up to the closure of the epithelium, additional antibiotic eye drops 3 times daily are prescribed as well as a wetting agent if necessary. Visual recovery is relatively slow, as shown in the attached data analysis. The average achievable visual acuity is between 0.6 and 0.8 (Table 2). Epikeratophakia - VA

1,00 0,90 0,80 0,70 0,60

Mean + STD

0,50

●

0,40

Mean - STD

0,30 0,20 0,10 0,00

n=95 preap

n=66

n=55

n=53

n=60

n=37

n=20

n=9

n=7

1 mo

3 mo

6 mo

Table 2. Development of visual acuity in original BKS-cut Epi

Mean

Ch ap ter 2 Epikerat ophak i a t ec hn i q u e an d ker at o c o n u s

Since the method described does not intend to reduce the cone radii, but the refractively modified button is placed on top of the pathology, the target size is not related to the flattening achieved. The aim is to achieve a constant refractive final result (Table 3), stop the progression of keratoconus and thus arrest the disease process. The achievable refractive correction can currently be estimated at ± 2.5 diopters. Cylinder corrections and high corrections of more than 5 diopters can be reduced to a range well tolerated by spectacle correction, usually to less than 2.5 diopters. Epikeratophakia - Radii

54,00 53,00 52,00 51,00 50,00 49,00 48,00

Mean + STD

47,00

●

46,00

Mean

Mean - STD

45,00 44,00 43,00 42,00 41,00 40,00

n=87 n=71 preap

1 mo

n=70

n=80

n=73

n=57

n=31

n=22

n=17

n=8

3 mo

6 mo

5y+

Table 3. Stability of Epikeratophakia-generated radii

COMPLICATIONS The most common complications that threaten the outcome are compression, traction and infiltrates in the suture channels. These occur more frequently on the donor tissue side, and in these cases, it is usually possible to maintain the epi-disk vitality by antibiotic irrigation of the suture channels. Such findings may result from dehydration occurring in previously highly edematous disks. Surgically, in particular, diameter discrepancies between the recipient bed and trephination can lead to compression with Descemet’s folds.

DISCUSSION Epikeratophakia is a potentially valuable procedure because of its reversibility, low surgical risk to the patient’s cornea and refractive correction in keratoconus. Improvements in the method exist from the use of a femtosecond laser, both for the production of the surface parallel geometry of the epi-disk and for its refractive treatment with the excimer laser. The procedure could thus be reduced from the current operating time of 1.5 hours to less than half of that. 27

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The advantages of the method are obvious: the curtailing of the increase of the cone is achieved on a regular basis. In cases of complications, the disk can be removed, and the initial state can be restored. The use of a TLKP nor a PKP is not prevented nor made more difficult. Many of the complications relating to the unpredictable and unequal dimensions between the epi rim and trephination diameter can be avoided by using lasers as above. Donor buttons from eye banks are frequently swollen and must be thinned, thereby changing the diameter. Disparate size ratios between the disk and bed can be avoided if the extent of swelling of the disk supplied by the eye bank is known. The possibilities currently available make the procedure the safest correction method for keratoconus since the typical complications of perforating keratoplasty, in particular the risk of immune reaction and the induction of irregular astigmatism, are not seen clinically. Nor does the risk of perforation of Descemetâ&#x20AC;&#x2122;s membrane, as with deep lamellar keratoplasty, exist. On the other hand, the method is the only one that offers a refractive primary correction with the excimer laser in the corneal parenchyma so that high ametropias can be avoided. (fig. 12, 13, 14) Additional correction is possible after removing the sutures by performing a PRK.

Figure 12. 8 mm plano BKS-cut epi button on 57 D keratoconus, visual acuity 0.6

Ch ap ter 2 Epikerat ophak i a t ec hn i q u e an d ker at o c o n u s

Figure 13. 8 mm excimer-cut epi with 300 Âľm thickness 6 months postoperatively

Figure 14. OCT picture showing excimer-cut epi on a keratoconus cornea, which is flattening a cone of 6 D evenly

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REFERENCES 1 Kaufman, H. E. (1980). The correction of aphakia: XXXVI Edward Jackson memorial lecture. American journal of ophthalmology, 89(1), 1-10. 2 Werblin, T. P., Kaufman, H. E., Friedlander, M. H., & Granet, N. (1981). Epikeratophakia: The surgical correction of aphakia: III. Preliminary results of a prospective clinical trial. Archives of Ophthalmology, 99(11), 1957-1960. 3 McDonald, M. B., Kaufman, H. E., Durrie, D. S., Keates, R. H., & Sanders, D. R. (1986). Epikeratophakia for keratoconus: The nationwide study. Archives of ophthalmology, 104(9), 1294-1300. 4 McDonald, M. B., Kaufman, H. E., Aquavella, J. V., Durrie, D. S., Hiles, D. A., Hunkeler, J. D., ... & Sanders, D. R. (1987). The nationwide study of epikeratophakia for aphakia in adults. American journal of ophthalmology, 103(3), 358-365. 5 Krumeich, J. H., & Swinger, C. A. (1987). Nonfreeze epikeratophakia for the correction of myopia. American journal of ophthalmology, 103(3), 397-403. 6 Werblin, T. P., Kaufman, H. E., Friedlander, M. H., McDonald, M. B., & Sehon, K. L. (1982). Epikeratophakia—the surgical correction of aphakia: Update 1981. Ophthalmology, 89(8), 916-920. 7 Werblin, T. P., Kaufman, H. E., Friedlander, M. H., & Granet, N. (1981). Epikeratophakia: The surgical correction of aphakia: III. Preliminary results of a prospective clinical trial. Archives of Ophthalmology, 99(11), 1957-1960. 8 Anwar, M. (1974). Technique in lamellar keratoplasty. TRANSACTIONS OF THE OPHTHALMOLOGICAL SOCIETIES OF THE UNITED KINGDOM, 94(APR), 163-171. 9 Krumeich, J. H., Daniel, J., & Knülle, A. (1998). Live-epikeratophakia for keratoconus. Journal of Cataract & Refractive Surgery, 24(4), 456-463.

3 Incisional refractive correction Richard Packard IN THE BEGINNING The idea of correcting refractive error by surgery is not new. In the chapter in this book on lens removal for refractive purposes we see the “Fukala operation” for high myopia emanating from the end of the 19th century. At the same time also in Europe a wholly different approach using corneal incisions was being investigated which would predate radial keratotomy (RK) by 75 years. The story of Leendert Jans Lans, the Dutch ophthalmic surgeon, is told most eloquently by the late George Waring III in an editorial in the Journal of Refractive Surgery from 1987. The 1journal has given permission for it to be reproduced here. You will see that the basics of RK were well understood by Lans from his meticulous investigations initially in rabbit studies (fig.1 a and b).

SATO AND A NEW START Lans’s work was entirely forgotten and our story now moves to Japan in the late 1930s. Japan had been at war since July 1937 fighting China. High myopia was a very common refractive error amongst the soldiers and losing a pair of glasses could render a soldier unable to fight. There was therefore an imperative to find a solution. One of the approaches was tried by an ophthalmologist who was a professor at Juntendo University, Tsutomu Sato. He was a prominent corneal surgeon who had observed the effect that hydrops in keratoconus patients had in flattening the cornea2. He felt that if he made incisions in Descemet’s membrane of the cornea, he could induce a similar flattening which would reduce myopia. Sato conducted further experimental work using both anterior and posterior keratotomies in the 1940s reporting promising results for up to 4.00 D of myopia. In the early 1950s, hundreds of patients underwent anterior and posterior keratotomies. The results of 32 of these eyes were published in 19533. Later in the 1950s, Sato stopped this surgery as contact lenses as a less invasive approach became more readily available. However, the major issue with the Sato technique was due to the lack of knowledge of the importance of the corneal endothelium. This meant that many patients subsequently developed corneal decompensation in later years (fig.2). Of the retrieved medical records of patients who underwent surgery at Juntendo University between 1953 and 1959, 78.6 per cent had bullous keratopathy occurring at an average time of 26.9 years after surgery. By the time he died in 1960 Sato’s work had been largely discredited.

RADIAL KERATOTOMY COMES TO THE WORLD Svyatoslav Fyodorov (fig.3), one of the USSR’s great ophthalmic innovators, started radial kera31

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A Figure 1a and b. Waring G. The Lans Distinguished Refractive Surgery Lecture. J Refract Surg. 1987;3(4):115-116

C hapter 3 In c i si on al r ef r ac t i v e c o r r ec t i o n

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Figure 2. Bullous keratopathy in an eye 20 years after the Sato operation

Figure 3. Sviatoslav Fyodorov (1927-2000)

C hapter 3 In c i si on al r ef r ac t i v e c o r r ec t i o n

totomy to the Soviet Union in the early 1970s but initially encountered poor results4. The reason he started RK at all is not clear some accounts describe how he had come upon the idea by chance. Fyodorov was treating the eye of a boy who had been in a bicycle accident; his glasses had shattered upon impact and glass particles had become lodged in his cornea. In an attempt to save his vision, Fyodorov performed a procedure during which he made a number of radial incisions in the boy’s eye, extending in a radial pattern from the pupil to the periphery of the cornea, ironically, rather like the spokes in a bicycle wheel. The glass was removed and, after allowing time for the wounds to heal, Fyodorov examined the eyes again and was surprised to discover that the boy’s vision had improved significantly. In fact, his visual acuity was superior to that achieved before his accident. From this discovery, the radial keratotomy procedure first came about. What seems more likely is that he heard about Sato’s operation at a Japanese Ophthalmological Society meeting that he attended in Japan in 1960. Once he started to work on the procedure much of the laboratory work was done by Valeri Durnev. It was he who noticed that the effect of the keratotomy increased as the clear optical zone decreased. The keratotomy was performed by making depth measured radial incisions at the periphery of the anterior surface of the cornea5. This was done using metal, and then diamond keratomes, resulting in the flattening of the central optical zone, which remained optically intact. Initial studies were limited to finding the optimal number and shape of corneal radial incisions in optical and morphological terms. In 1979, Yenaleyev, also in the Soviet Union, had performed radial keratotomy using four to 24 anterior incisions. He found that 73 per cent of the 426 eyes operated on, remained stable with 27 per cent regressing6. Fyodorov found that once serious clinical testing had taken place it was possible to create a multi-factorial formula for predicting the effect of the incisions. It allowed accurate calculation of the number and depth of incisions to be made. This would help to predict the results of the surgery, thus minimizing risk of complications and refractive errors. Throughout the 1970s and 80s further refinements to the technique were established with improved results. Leo Bores brought radial keratotomy to the USA in 19787. He had been so fascinated at what Fyodorov was doing that he wanted to go and watch him in the USSR. To that end he learnt to speak Russian. RK subsequently stimulated considerable worldwide interest not least because of the “ the Russian conveyor belt” (f ig.4).

Figure 4. “Medical factory” No 1 the “Russian conveyer belt”

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RK thus became the first surgery to be used worldwide for the correction of refractive errors in the modern era, leading to a new phase in ophthalmic surgery. Refinements to the surgical procedure, in addition to advances in the design of guarded knives and microscopes, improved accuracy. It was found that whilst an increased number of incisions up to 16 induced greater refractive effects increasing this added no further benefit and could have the opposite effect8. Most practitioners of this surgery used four or eight incisions, depending on the refractive error for the correction of up to 6.00 D of myopia. Using 16 incisions had only a 5–10 per cent further effect over eight incisions. Radial keratotomy incisions result in a peripheral elevation, which in turn causes central corneal flattening. The deeper and more central incisions the incisions are the greater the effect. Further modifications to increase the refractive effect included multizone RK. Incisional direction also varied. Typically, the incisional direction was from the optical zone to the limbus in America but limbus to optical zone in the Soviet Union9,10. Centrifugally placed RK incisions (American technique) (fig.5) provide greater safety regarding unintended incisions crossing the clear optical zone. These incisions tend to have a variable depth and have a bevelled incision profile at the central optical zone. Centripetally placed RK incisions (Russian technique)(fig.6) are deep incisions but carry the risk of inadvertently entering the optical zone. These incisions often are not perfectly straight because of the natural tendency of the knife to stray when cutting with the vertical edge. The double-pass technique (fig.7) offers the benefits of both the Russian and American techniques. The initial incision is centrifugal and can be expected to create a bevelled incision profile at the central optical zone. The blade is then pushed centrally from the peripheral 8-mm optical zone mark, deepening the initial incision until it can no longer be extended centrally. The two-step diamond blade is sharpened only on the bottom 250μ of the vertical facet. Note the slight undercutting of the central optical zone. Figure 8 shows us a clinical photograph of an eye with a 4 incision correction.

Figure 5. “American” RK incision

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Figure 6. “Russian” RK incision

Figure 7. “Double pass” RK incision

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Figure 8. 4-incision radial keratotomy

RK knives started out as crude fragments of razor blade but quickly developed into very accurate diamond knives that could be adjusted with a micrometer screw to reflect the desired depth in the corneal incision (fig.9,10A, B). To help to choose the correct depth setting pachymetry of the cornea became mandatory. 38

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Figure 9. Micrometer diamond knife

Figure 10. A. The diamond blade depth is calibrated with a micrometer-precision microscope. B. The magnified image allows for precise and reproducible blade depth.

THE PERK STUDY When RK started to become popular in the USA there had been little if any evidence of the results of this surgery in the peer reviewed literature. This concerned a number of US surgeons and encouraged by George Waring III (fig.11) at Emory University in Atlanta funding was obtained from the National Eye Institute for a prospective study. In 1981, the Prospective Evaluation of Radial Keratotomy (PERK) study which involved nine‐ centres in the USA commenced. The study reported results at 4, 5 and 10‐year follow‐up11. The data from this study, despite variable optical zones and non‐use of nomograms, found that of 427 patients (793 eyes that underwent radial keratotomy), 374 patients (88%) (693 eyes) returned for 39

HISTORY OF REFRACTIVE SURGERY

Figure 11. George Waring III (1941-2015)

the 10-year examination. Of 675 eyes with refractive data, 38% had a refractive error within 0.50 D and 60% within 1.00 D. For 310 first-operated eyes, the mean refractive error was -0.36 D at 6 months and changed in a hyperopic direction to + 0.51 D at 10 years. The average rate of change was +0.21 D/y between 6 months and 2 years and +0.06 D/y between 2 and 10 years. Between 6 months and 10 years, the refractive error of 43% of eyes changed in the hyperopic direction by 1.00 D or more. The hyperopic shift was statistically associated with the diameter of the clear zone. Uncorrected visual acuity was 20/20 or better in 53% of 681 eyes and 20/40 or better in 85%. Loss of spectacle-corrected visual acuity of 2 lines or more on a Snellen chart occurred in 3% of all 793 eyes that underwent surgery. Among 310 patients with bilateral radial keratotomy, 70% reported not wearing spectacles or contact lenses for distance vision at 10 years. The conclusion from the study was that although the procedure could certainly reduce the need for glasses in 70% of those treated there was a significant hyperopic shift in more than 40% of patients. Neovascularisation along the radial incisions may also induce regressive effects. The diurnal variation often found in the early stages after surgery probably resulted from corneal oedema but in a number of patients, persisted12. 40