SECTION I
Evolution, Preoperative Considerations and Eye Banking
Today, the keratoplasty is considered as the most frequently performed and the most successful organ transplantation technique worldwide. The success of this procedure has not been an overnight event. The history of today's corneal grafting dates back to the nineteenth century when K Himly of Germany suggested replacing an opaque cornea of one animal with clear cornea of another animal (1813). F Reisinger was the first to suggest replacing opaque human cornea with transparent animal cornea in 1824. He also coined the term ‘keratoplasty’. SLL Bigger performed the first successful penetrating allograft in animals. Henry Power reported his experimental work on animals and humans in 1872.1 He was the first to give importance to proper graft placement, freedom from infection, usage of fresh donor tissue and the minimal trauma to the endothelium. In 1886, Von Hippel reported the first lamellar corneal grafting.2 The first successful penetrating keratoplasty was performed almost a century ago by Edward Konrad Zirm (Fig. 1.1) on a patient in the year 1906, who had sustained alkali burns.3 The donor was an 11-year-old boy whose eye was enucleated because of penetrating scleral injury with retained intraocular foreign body. In the next 30 years grafting was performed using tissue from enucleated eyes of living donors. In 1908, Plange performed the first autokeratoplasty, where he replaced the scarred cornea of a blind eye with a lamellar graft from the patient's other eye which, although blind had a normal cornea.
VP Filatov, a Russian ophthalmologist, is considered as the father of modern eye banking.4,5 He used an egg membrane to fixate the graft. This method was later practised widely. His work also involved the usage of cadaver cornea as the donor material and he highlighted the importance of protecting the intraocular tissues while trephining the host tissue and advocated direct suturing. In 1940s, corneal transplant surgery evolved dramatically with the availability of antibiotics and introduction of steroids in corneal surgery.
In late 1950s, small fine needles were used for first time for suturing. At the same time, Paufique and Charleux popularized lamellar corneal grafting. They also introduced limbal and eccentric grafts. Although, most of the corneal transplant surgery has evolved in the first-half of the 20th century, the greatest advances in corneal grafting have taken place in the past 30 years. The understanding of corneal anatomy and physiology especially with regard to the corneal endothelium, introduction of microsurgical techniques, advances in corneal preservation, the elucidation of the corneal immunology and the development of usage of anti-inflammatory and immunosuppressive agents have resulted in a high success rate of corneal grafting.
Corneal graft rejection is the greatest limiting factor in graft survival and Edward Maumenee was the one to recognize this clinical entity. The classic scientific description and experimental models were elegantly designed by Khodadoust.
Ramon Castroviejo (Fig. 1.2) performed the world's first successful human cornea transplant. He devised numerous instruments which were named after him, such as Castroviejo Calipers, Forceps, Corneal Scissors, Corneoscleral Punch, Cyclodialysis Spatula, Needle Holder, Tying Forceps, Suturing Forceps. He was also a pioneer of various surgical techniques in the field of keratoplasty. Castroviejo's original suturing technique used a continuous silk suture coursing across the external surface of a square graft, holding the graft in place using intraocular pressure to support the graft against the suture.2
Many of his square grafts fared extremely well and provided good visual acuity for many years.
Richard Troutman designed a microscope and numerous microsurgical instruments.6 He tackled the problem of astigmatism, invented surgical keratometer and the technique of wedge resection.
Townley Paton (Fig. 1.3) was first to set-up an eye bank in New York in 1959. Later on, this led to setting up of Eye Bank Association of America in 1961. This organization laid down the standards for obtaining, preservation, storage and usage of donor tissue. The healthy functioning endothelium is the key to success of a corneal graft. The specular microscope developed by Maurice has provided the means of studying donor and transplanted endothelium.
The preservation of donor cornea influences the outcome of surgery to a great extent. A preservation procedure besides ensuring the endothelium viability also enables safe transportation of material and increases the duration of storage, so that an efficient use of donor cornea can be made. First successful transplantation using a cryopreserved human donor tissue was reported by East Cott in 1954. Capella and Kaufman7,8 developed the basic method of cryopreservation in 1965. The major break-through in corneal preservation came with the introduction of MK medium by McCarey and Kaufman in 1974.9 This medium is quite reliable for storage of donor cornea for at least 3-4 days. This allowed the elective planning for surgery and made corneal transplantation a scheduled procedure rather than an emergency.
In the last two decades, with the improvement in surgical techniques and instrumentation lamellar keratoplasty has undergone a revolution. The various types of lamellar keratoplasty include anterior and posterior lamellar keratoplasty depending on the level of pathology. With the advent of the microkeratomes, automated lamellar therapeutic keratoplasty (ALTK) has given way to manual lamellar keratoplasty.
Deep lamellar keratoplasty was introduced to improve the postoperative visual performance in cases with corneal pathology involving the stromal layers of the cornea. It provides all the advantages of lamellar keratoplasty such as extraocular technique, less stringent criteria for donor tissue, less graft rejection and intraocular complications and yet offers a better visual acuity in terms of contrast sensitivity. In 1974, Anwar described the use of big air bubble for deep dissection under direct visualization in the potential natural cleavage plane between the Descemet's membrane and the overlying stromal layers.10 Archilla in 1980s, was first to use intrastromal air injection and spatula dissection to facilitate access to Descemet's membrane without perforating it.11 Sugita also described hydrodelamination of the stroma from Descemet's membrane.12 Melles described the technique of deep anterior lamellar keratoplasty (DALK) in which deeper dissection was done with the help of viscoelastic injection through the lamellar stromal pocket.13 In 2002, Anwar and Teichmann described the “big bubble” technique in which separation of Descemet's membrane from the overlying stroma is achieved with injection of air.14
Endothelial keratoplasty (EK) is an alternative to penetrating keratoplasty in cases where corneal endothelium is diseased alone. In 1998, Melles described a technique for posterior lamellar keratoplasty (PLK),15 and a year later, he successfully implemented the technique for pseudophakic corneal edema. In 2001, Terry and Ousley reported successful results in patients using similar procedure, which they named deep lamellar endothelial keratoplasty (DLEK).16 Price and Price made the endothelial keratoplasty technique more popular and it was known as Descemet's stripping endothelial keratoplasty (DSEK).17 In 2006, Gorovoy described the technique of Descemet's-stripping automated endothelial keratoplasty (DSAEK) in which the manual stromal dissection was replaced by the microkeratome dissection.18 This method avoids all manual lamellar dissections and has the potential to result in a smoother interface.
In 2006, Tappin described the clinical transplantation of 7.5 mm diameter Descemet's membrane (DM) through an 8.0 mm scleral incision using a flat carrier device.19 In the same year Melles described the first clinical results of DM transplantation through a self-sealing corneal incision and referred it to as Descemet's membrane endothelial keratoplasty (DMEK).20 Further experimental studies are on to make cultured human endothelial cell transplantation successful.3
Major contributions in the field of corneal transplantation | |||
|---|---|---|---|
S.No. | Year | Name | Contribution |
1. | 1813 | K Himly | Suggested replacing opaque cornea in one animal with clear cornea from another animal. |
2. | 1824 | F Reisinger | Suggested replacing opaque human cornea with clear animal cornea |
• Coined the term keratoplasty | |||
3. | 1837 | SLL Bigger | Successfully performed corneal allograft in animals |
4. | 1872 | Henry Power | Experimental corneal grafting |
5. | 1880 | Von Hippel | • Introduced lamellar keratoplasty |
• Invented circular trephine | |||
6. | 1906 | Edward Konrad Zirm | • Reported first successful penetrating keratoplasty in a human |
7. | 1908 | Plange | • Autokeratoplasty |
8. | 1910-1950 | VP Filatov | • Father of keratoplasty |
• Performed systematic study of keratoplasty | |||
• Suggested using cadaver corneas as donor tissues | |||
• Devised numerous instruments and surgical innovations | |||
9. | 1930-1950 | R Castroviejo | • Devised numerous instruments for microsurgery |
10. | 1950s | Paufique and Charleux | • Lamellar keratoplasty |
• Limbal and Eccentric Grafts | |||
11. | 1944 | RT Paton | • Founded the first Eye Bank in USA |
12. | 1954 | East Cott | • Transplantation using cryopreserved cornea |
13. | 1960 | E Maumenee | • Recognition of “Graft Rejection” as a clinical entity |
14. | 1965 | Troutman | Surgical microscope and surgical keratometer |
15. | 1965 | Capella and Kaufman | • Cryopreservation |
16. | 1968 | D Maurice | • Developed Specular Microscope |
17. | 1974 | B McCarey and H Kaufman | • Developed Corneal Storage Media |
18. | 1985 | Archila EA | DALK with air assisted dissection |
19. | 1998 | Melles GR | Deep anterior lamellar keratoplasty |
Posterior lamellar keratoplasty | |||
20. | 2001 | Mark Terry | Deep lamellar endothelial keratoplasty (DLEK) |
21. | 2006 | Price and Gorovoy | Descemet's stripping endothelial keratoplasty (DSEK) and |
Descemet's stripping automated endothelial keratoplasty (DSAEK) | |||
22. | 2006 | Melles GR | Descemet's membrane endothelial keratoplasty (DMEK) |
REFERENCES
- Power H. IV International Congress of Ophthalmology. London 1872; 4: 172.
- Von Hippel A. Albrecht v. Graefes Arch Ophthalmol 1888; 34: 108.
- Zirm EK. Eine erfolgreiche totale keratoplastik. V. Graefes Arch Ophthalmol 1906; 64: 580.
- Filatov VP. Transplantation of the cornea. Arch Ophthalmol 1935; 13: 321–47.
- Filatov VP, Bajenova MA. Culture of dried corneal tissue. Arch Ophthalmol and Rev Gen Ophthalmol 1937; 1: 385.
- Troutman RC. The operating microscope in ophthalmic surgery. Trans Am Ophthalmol Soc 1965; 63: 335–48.
- Capella JA, Kaufman HE, Robbine JE. Preservation of viable corneal tissue. Arch Ophthalmol 1965; 74: 669–73.
- McCarey BE, Kaufman HE. Improved corneal storage. Investigative Ophthalmol 1974; 13: 165–73.
- Lindstrom RL. Advances in corneal preservation. Trans Am Ophthalmol Soc 1990; 88: 555–648.
- Anwar M. Dissection technique in lamellar keratoplasty. Br J Ophthalmol 1972; 56 (9): 711–13.
- Archila EA. Deep lamellar keratoplasty dissection of host tissue with intrastromal air injection. Cornea 1984-1985; 3 (3): 217–18.
- Sugita J, Kundo J. Deep anterior lamellar keratoplasty with complete removal of pathological stroma for visual improvement. Br J Ophthalmol 1997; 81: 184–88.
- Melles GR, Lander F, Rietveld FJ, Remeijer L, Beekhuis WH, Binder PS. A new surgical technique for deep stromal, anterior lamellar keratoplasty. Br J Ophthalmol 1999; 83 (3): 327–33.
- Anwar M, Teichmann KD. Big-bubble technique to bare Descemet's membrane in anterior lamellar keratoplasty. J Cataract Refract Surg 2002; 28 (3): 398–403.
- Melles GR, Eggink FA, Lander F, Pels E, Rietveld FJ, Beekhuis WH, et al. A surgical technique for posterior lamellar keratoplasty. Cornea 1998; 17: 618–26.
- Terry MA, Ousley PJ. Deep lamellar endothelial keratoplasty in the first United States patients: early clinical results. Cornea 2001; 20: 239–43.
- Price FW Jr, Price MO. Descemet's stripping with endothelial keratoplasty in 50 eyes: a refractive neutral corneal transplant. J Refract Surg 2005; 21: 339–45.
- Gorovoy MS. Descemet's stripping and automated endothelial keratoplasty. Cornea 2006; 25: 886–89.
- Tappin M. A method for true endothelial cell (Tencell) transplantion using a custom made cannula for the treatment of endothelial cell failure. Eye 2007; 21: 775–79.
- Melles GRJ, Ong TS, Ververs B, van der Wees J. Descemet's membrane endothelial keratoplasty (DMEK). Cornea 2006; 25: 987–90.