Interventional procedures consultation document - intraocular lens insertion for correction of refractive error, with preservation of the natural lens
NATIONAL INSTITUTE FOR HEALTH AND CLINICAL EXCELLENCE
Interventional Procedure Consultation Document
Intraocular lens insertion for correction of refractive error, with preservation of the natural lens
| Short-sightedness is the inability to see clearly at a distance. Eyesight can usually be corrected by wearing spectacles or contact lenses. Insertion of a clear plastic lens in front of the existing lens is a procedure that aims to improve vision in short-sightedness. |
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The National Institute for Health and Clinical Excellence (NICE) is examining intraocular lens insertion for correction of refractive error, with preservation of the natural lens 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 intraocular lens insertion for correction of refractive error, with preservation of the natural lens. 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 our 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 We also ask consultees to highlight any ways in which draft guidance fails to promote equality or tackle discrimination and give suggestions for how it might be improved. Closing date for comments: 25 November 2008 Target date for publication of guidance: February 2009 |
| Note that this document is not the Institute's guidance on this procedure. The recommendations are provisional and may change after consultation. |
| 1 | Provisional recommendations |
| 1.1 | Current evidence on intraocular lens (IOL) insertion for correction of refractive error with preservation of the natural lens is available for large numbers of patients and raises no major safety concerns. There is good evidence of short-term efficacy. However, there is the possibility of an increased risk of retinal detachment in people with a high degree of myopia, and there are no long-term data about this. Therefore, the procedure may be used with normal arrangements for clinical governance and audit, but with special arrangements for consent. |
| 1.2 | Clinicians wishing to undertake the procedure should ensure patients understand the risks of having an artificial lens implanted for visual impairment that might otherwise be corrected using spectacles or contact lenses. They should understand the possibility of retinal detachment associated with a high degree of myopia, and the lack of evidence relating to long-term outcomes. Patients should be provided with clear written information. In addition, the use of the Institute's information for patients ('Understanding NICE Guidance') is recommended (available from www.nice.org.uk/IPGXXXpublicinfo). [[details to be completed at publication]] |
| 1.3 | Both clinicians and manufacturers are encouraged to collect long-term data on people who undergo IOL insertion, and to publish their findings. NICE may review the procedure on publication of further evidence. |
| 2 | The procedure |
| 2.1 | Indications and current treatments |
| 2.1.1 | There are several types of refractive error. Myopia occurs when light from a distant object is focused in front of the retina, so that close objects are seen clearly and more distant ones are blurred. Hypermetropia occurs when light entering the eye from distant objects is focused behind the retina so that distant objects are seen clearly but closer ones are blurred. Astigmatism occurs when light from objects is not focused sharply on the retina. Presbyopia is a condition where the crystalline lens becomes rigid and cannot change shape to focus. |
| 2.1.2 | Refractive errors are usually corrected by wearing either spectacles or contact lenses. Surgical treatments for myopia include photorefractive keratectomy (PRK), laser in situ keratomileusis (LASIK) and insertion of corneal implants. |
| 2.1.3 | The procedure may be indicated for people with a high degree of myopia, or those for whom wearing spectacles is difficult, for example because of a disability or professional requirements. |
| 2.2 | Outline of the procedure |
| 2.2.1 | The procedure is carried out with the patient under local anaesthesia. The pupil is dilated using topical medication, and a phakic IOL is inserted into either the anterior or the posterior chamber of the lens via a small corneal incision. Depending on its design, the phakic IOL is anchored to the iris, placed in the angle between the cornea and the iris, or positioned to float over the surface of the natural lens. A nylon suture is sometimes used to close the incision. |
| 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/IP706overview. | |
| 2.3 | Efficacy |
| 2.3.1 | Mean manifest refraction spherical equivalent (MRSE) in a randomised controlled trial of 50 eyes (with the fellow eye as control) was –0.95 ± 0.45 D in eyes implanted with a phakic IOL and –0.74 ± 0.67 D in eyes treated with LASIK at 1-year follow-up (p not significant). A non-randomised controlled trial of 9239 eyes reported that mean postprocedural MRSE was –1.78 ± 2.03 D in eyes implanted with a phakic IOL, 0.36 ± 1.30 D in LASIK-treated eyes and –0.18 ± 0.5 D in PRK-treated eyes (level of significance not stated). |
| 2.3.2 | A randomised controlled trial of 88 astigmatic eyes reported that mean best spectacle-corrected visual acuity (BSCVA) of 20/12.5 or better at 1 year was achieved in 71% (27/38) of eyes implanted with a toric phakic IOL and in 14% (6/44) of eyes treated with PRK (p < 0.001). In a non-randomised controlled trial of 769 eyes, correction to within 0.5 D of that intended was achieved in 69% (127/184) of phakic IOL-treated eyes and 57% (57/100) of LASIK-treated eyes at 1‑year follow-up (p = 0.05). |
| 2.3.3 | A case series of 1140 eyes treated with phakic IOL implantation reported that at baseline 0% (0/622) of eyes had uncorrected visual acuity (UCVA) of 20/20 or better; at 3-year follow-up 27% (62/231) of eyes had UCVA of 20/20 or better (level of significance not stated). |
| 2.3.4 | The Specialist Advisers stated that the key efficacy outcomes for this procedure included improvements in UCVA and BSCVA, independence from optical aids, and maintenance of quality of vision. |
| 2.4 | Safety |
| 2.4.1 | In a non-randomised controlled trial of 9239 eyes, retinal detachment was reported in 4% (12/294) of eyes implanted with a phakic IOL, < 1% (11/3009) of eyes treated with LASIK and < 1% (9/5936) of eyes treated by PRK (retinal detachments occurred after a mean of 20.5, 24.6 and 53.6 months, respectively). |
| 2.4.2 | An anterior subcapsular cataract was reported in 2% (1/43) of eyes implanted with a toric phakic IOL in a randomised controlled trial of 88 eyes at 2-year follow-up. |
| 2.4.3 | A case series of 263 eyes implanted with a phakic IOL reported halo and glare symptoms in 60% (157/263) of treated eyes at 1-year follow-up (reported as ‘significant' in 21% [54/263]). |
| 2.4.4 | The Specialist Advisers stated that key safety outcomes included glaucoma, loss of lines of BSCVA, reduced contrast sensitivity, night vision disturbances and the need for additional refractive surgery. Theoretical adverse events included endophthalmitis and bio-incompatibility of the IOL. |
| 3 | Further information |
| 3.1 | Clinicians must report any instances of lens removal because of adverse events to the Medicines and Healthcare products Regulatory Agency (MHRA). |
| 3.2 | NICE has published interventional procedures guidance on several procedures relating to refractive error and IOL insertion. For more information see www.nice.org.uk. |
Bruce Campbell
Chairman, Interventional Procedures Advisory Committee
September 2008
This page was last updated: 30 March 2010