Corneal endothelial transplantation (interventional procedures consultation)
NATIONAL INSTITUTE FOR HEALTH AND CLINICAL EXCELLENCE
Interventional procedure consultation document
Interventional procedure overview of insertion of corneal endothelial transplantation
| Some diseases can affect the clear section at the front of the eye (the cornea), and in particular the layers that help to maintain its clarity (the endothelium). Instead of a whole corneal transplantation, this procedure aims to replace the innermost layers of the cornea with a healthy section from a donor eye, leaving the rest of the cornea in place. Eye medication is given for a short time after surgery. |
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The National Institute for Health and Clinical Excellence (NICE) is examining interventional procedure overview of corneal endothelial transplantation and will publish guidance on its safety and efficacy to the NHS in England, Wales, Scotland and Northern Ireland. NICE's Interventional Procedures Advisory Committee has considered the available evidence and the views of Specialist Advisers, who are consultants with knowledge of the procedure. The Advisory Committee has made provisional recommendations about corneal endothelial transplantation. This document summarises the procedure and sets out the provisional recommendations made by the Advisory Committee. It has been prepared for public consultation. The Advisory Committee particularly welcomes:
Note that this document is not NICE's formal guidance on this procedure. The recommendations are provisional and may change after consultation. The process that NICE will follow after the consultation period ends is as follows.
For further details, see the Interventional Procedures Programme manual, which is available from the NICE website (www.nice.org.uk/ipprogrammemanual). NICE is committed to promoting through its guidance race and disability equality and equality between men and women, and to eliminating all forms of discrimination. One of the ways we do this is by trying to involve as wide a range of people and interest groups as possible in the development of our guidance on interventional procedures. In particular, we aim to encourage people and organisations from groups in the population who might not normally comment on our guidance to do so. We also ask consultees to highlight any ways in which draft guidance fails to promote equality or tackle discrimination and give suggestions for how it might be improved. NICE reserves the right to summarise and edit comments received during consultations, or not to publish them at all, where in the reasonable opiPercutaneous endoscopic laser cervical discectomy nion of NICE, the comments are voluminous, publication would be unlawful or publication would otherwise be inappropriate. Closing date for comments: 24 March 2009 Target date for publication of guidance: June 2009 |
| 1 | Provisional recommendations |
| 1.1 | Current evidence on the safety and efficacy of corneal endothelial transplantation is adequate to support the use of this procedure provided that normal arrangements are in place for clinical governance, consent and audit. |
| 1.2 | NHS Blood and Transplant (formerly UK Transplant) run a corneal transplant register, and clinicians should submit details about all patients undergoing corneal endothelial transplantation to this register (www.nhsbt.nhs.uk). |
| 1.3 | NICE encourages publication of long-term outcomes from register or research data. |
| 2 | The procedure |
| 2.1 | Indications and current treatments |
| 2.1.1 | The corneal endothelium is a single layer of cells comprising the innermost layer of the cornea and is responsible for removing excess fluid from the cornea to maintain its transparency. Dysfunction of the endothelium leads to progressive corneal clouding and haze, resulting in visual impairment. The most common causes of corneal endothelium dysfunction are Fuchs' dystrophy (a genetic disorder) or degenerative changes (bullous keratopathy). Other reasons for endothelial dysfunction may include trauma, infection or iatrogenic damage. |
| 2.1.2 | Current surgical treatment for corneal endothelial disease is penetrating keratoplasty (PK) (whole cornea transplantation), which requires multiple sutures to anchor the donor cornea in the recipient eye. |
| 2.2 | Outline of the procedure |
| 2.2.1 | Corneal endothelial transplantation uses one of a range of techniques in which the diseased corneal endothelium is replaced with cadaveric donor endothelial graft, while the healthy portions of the patient's cornea are retained. It may be performed with the patient under local or general anaesthesia. A scleral incision is made and a tunnel to the anterior chamber is created. The diseased endothelium is separated from the cornea: it can be either dissected manually or with the aid of a laser. The donor corneal endothelial graft is then inserted through the scleral incision, together with viscoelastic material, to help secure the graft in place. |
| 2.2.2 | Topical and/or systemic antibiotics, steroids and immunosuppressants are often prescribed for a short period after surgery. |
| Sections 2.3 and 2.4 describe efficacy and safety outcomes from the published literature that the Committee considered as part of the evidence about this procedure. For more detailed information on the evidence, see the overview, available at www.nice.org.uk/IP715overview. |
| 2.3 | Efficacy |
| 2.3.1 | A randomised controlled trial (RCT) of 28 eyes reported significantly better mean uncorrected visual acuity (UCVA) in 13 eyes treated by endothelial keratoplasty (EK) (0.60 ± 0.20) compared with 15 eyes treated by PK (0.87 ± 0.30) at 6-month follow-up (p = 0.01). This difference was maintained at 12-month follow-up with UCVAs of 0.54 ± 0.21 and 0.80 ± 0.32 in the EK and PK groups, respectively (p = 0.05). The RCT reported no significant difference in mean best spectacle-corrected visual acuity (BSCVA) between the EK and PK groups at 1-, 3-, 6- or 12-month follow-up. A non-randomised comparative study of 177 eyes (129 treated by EK) reported that BSCVA (p = 0.001) and UCVA (p = 0.05) were significantly better after EK than after PK at 15‑month follow-up. The RCT did not report any significant difference in contrast sensitivity between the groups (median follow-up 12 months). |
| 2.3.2 | The non-randomised comparative study of 177 eyes reported that the incidence of astigmatism was significantly lower after EK than after PK (p < 0.0001) (mean follow-up 15 months). |
| 2.3.3 | The Specialist Advisers considered key efficacy outcomes to include UCVA, speed of visual rehabilitation, and quality of life measures such as the Visual Function Index (VF-14) score. |
| 2.4 | Safety |
| 2.4.1 | Three studies of 100, 118 and 16 eyes reported rates of conversion to PK during procedures planned as EK of 2% (2/100), 9% (11/118) and 19% (3/16) respectively. |
| 2.4.2 | The studies of 100, 118 and 16 eyes reported that a repeat EK procedure was required in 2% (2/98), 8% (10/118) and 8% (1/13) eyes. Reasons for repeat procedures varied but were often because of graft rejection. |
| 2.4.3 | A non-randomised comparative study of 907 eyes (199 treated by EK) reported that graft rejection rates (defined as any anterior chamber inflammatory episode with keratic precipitates on the transplanted endothelium requiring an unscheduled increase in steroid medication) were significantly lower in the EK group (8% [15/199]) than in the PK group (13% [92/708]) at 2-year follow-up (p = 0.04). The non‑randomised comparative study of 907 eyes also reported that graft failure after rejection (not otherwise defined) was lower in the EK group (7% [1/15]) than in the PK group (28% [26/92]) (p = 0.06). At 2-year follow-up, 80% of patients treated by EK continued to take topical steroids. A non-randomised comparative study of 177 eyes (129 treated by EK) reported no significant difference between the EK and PK groups in rate of graft rejection (p = 0.78) or primary graft failure (p = 0.91) (mean follow-up 15 months). |
| 2.4.4 | The non-randomised comparative study of 177 eyes reported that graft dislocation was significantly more common after EK than after PK (p = 0.0004). |
| 2.4.5 | In the comparative study of 177 eyes, there was no significant difference in percentage endothelial cell loss after EK or PK (p = 0.70) at 15-month follow-up. In a case series of 263 eyes treated by EK, a subset of 34 eyes with 2-year follow-up demonstrated cumulative endothelial cell loss (not otherwise defined) of 34% at 6 months, 36% at 12 months, and 41% at 24 months. |
| 2.4.6 | A case series of 118 eyes undergoing EK (41 of which had concomitant phacoemulsification and intraocular lens insertion for cataract) reported retinal detachment in 4% (5/118) of patients (sequelae not described; follow-up not stated). |
| 2.4.7 | The Specialist Advisers listed adverse events reported in the literature or anecdotally as graft dislocation, graft failure and rejection, interface opacification, and loss of BSCVA. |
| 2.5 | Other comments |
| 2.5.1 | The Committee noted that the techniques for this procedure are continuing to evolve |
Bruce Campbell
Chairman, Interventional Procedures Advisory Committee
December, 2008
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This page was last updated: 30 March 2010