Implantation of multifocal (non-accommodative) intraocular lenses during cataract surgery (interventional procedures consultation)

NATIONAL INSTITUTE FOR HEALTH AND CLINICAL EXCELLENCE

Interventional Procedure Consultation Document

Implantation of multifocal (non-accommodative) intraocular lenses during cataract surgery

A cataract is an eye condition in which the lens becomes cloudy over time, thereby affecting eyesight. During cataract surgery, the clouded lens is removed and replaced with an artificial lens, which provides clearer vision. Unlike standard intraocular lenses (IOLs), multifocal (non-accommodative) IOLs have areas with different focusing power with the aim of allowing near and distant objects to be seen without the need for spectacles.

The National Institute for Health and Clinical Excellence is examining implantation of multifocal (non-accommodative) intraocular lenses during cataract surgery and will publish guidance on its safety and efficacy to the NHS in England, Wales, Scotland and Northern Ireland. The Institute'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 implantation of multifocal (non-accommodative) intraocular lenses during cataract surgery.

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:

comments on the preliminary recommendations
the identification of factual inaccuracies
additional relevant evidence.

Note that this document is not the Institute's formal guidance on this procedure. The recommendations are provisional and may change after consultation.

The process that the Institute will follow after the consultation period ends is as follows.

The Advisory Committee will meet again to consider the original evidence and its provisional recommendations in the light of the comments received during consultation.
The Advisory Committee will then prepare draft guidance which will be the basis for the Institute's guidance on the use of the procedure in the NHS in England, Wales, Scotland and Northern Ireland.

For further details, see the Interventional Procedures Programme manual, which is available from the Institute's 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 how it might be improved.

Closing date for comments: 26 February 2008
Target date for publication of guidance: May 2008

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	The evidence on the implantation of multifocal (non-accommodative) intraocular lenses (IOLs) during cataract surgery raises no major safety concerns. Current evidence on the procedure's efficacy shows that it can provide good near and distance vision without the need for spectacles, but this is at the expense of a variety of potential visual disturbances. Clinicians wishing to use multifocal (non-accommodative) IOL implants during cataract surgery should therefore do so with normal arrangements for clinical governance and audit, but with special arrangements for consent.
1.2	Clinicians wishing to undertake implantation of multifocal (non-accommodative) IOLs during cataract surgery should ensure that patients understand the risks of the procedure, including the possibilities of halo and glare, and reduced contrast sensitivity. Patients should also be made aware that the lenses may be difficult to remove or replace. They 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	Patient selection should take into account factors that may prevent patients from wearing spectacles, such as disabilities that interfere with spectacle use, because these may be additional indications for the use of multifocal lenses.

The procedure

2.1

Indications and current treatments

2.1.1

A cataract is the opacification of the eye's natural lens. It usually causes gradual deterioration in eyesight, and may eventually lead to blindness.

2.1.2

Surgical treatment involves replacing the opacified lens with an artificial lens, usually of fixed power (monofocal), which therefore requires the use of reading spectacles for adequate near vision. More recently, IOLs have been developed which aim to give both near and distance uncorrected (without spectacles) vision, either by virtue of their design (multifocal lenses) or by their capacity to change shape within the eye in a similar manner to the native lens (see section 3.1).

2.2

Outline of the procedure

2.2.1

The procedure is identical to that of a standard cataract operation, but involves implanting a multifocal IOL. Multifocal IOLs have concentric areas of different refractive powers, allowing both near and distant objects to be focused on the retina simultaneously, with the brain selecting out the required image for attention. Various devices can be used for this procedure. Cataract surgery is usually performed under a local anaesthetic.

Sections 2.3 and 2.4 describe efficacy and safety outcomes which were available in the published literature and which the Committee considered as part of the evidence about this procedure. For more details, refer to the sources of evidence (see appendix).

2.3

Efficacy

2.3.1

In a systematic review of 10 randomised controlled trials (RCTs) which compared multifocal IOLs with monofocal lenses, spectacle dependence was reported to be 68% (316/467) in the multifocal IOLs group and 95% (383/404) in the monofocal IOLs group (odds ratio [OR] 0.17, 95% confidence interval [CI] 0.12 to 0.24). A non-randomised controlled trial of 280 patients reported that 92% of patients with multifocal IOLs and 80% of patients with monofocal IOLs were able to function without spectacles in the intermediate range (p = 0.004) (absolute numbers not reported).

2.3.2

The systematic review reported no significant difference in the proportion of patients achieving uncorrected distance visual acuity of 6/6 between those given multifocal or monofocal lenses (OR 1.05, 95% CI 0.67 to 1.63).

2.3.3

A non-randomised controlled trial of 102 patients reported uncorrected distance acuity of 20/40 or better and near acuity of Jaeger line 3 text ('J3'; the Jaeger system is a test of near visual acuity) or better in 77% (78/101) of patients with multifocal IOLs and 46% (46/101) of patients with monofocal IOLs (p < 0.0001). A case series of 671 patients reported distance acuity of 20/40 or better and near acuity of J3 or better in 50% of 'best case' (that is, without other preoperative pathology and no postoperative macular degeneration) multifocal IOL patients (absolute figures not reported).

2.3.4

Two of the RCTs included in the systematic review reported a statistically significant increase in patient satisfaction with overall vision with the multifocal IOL compared with the monofocal IOL, while two other RCTs reported no difference.

2.3.5

The Specialist Advisers considered key efficacy outcomes to include near and distance vision without the use of spectacles, postoperative refractive error, contrast sensitivity and quality of life.

2.4

Safety

2.4.1

The systematic review of 10 RCTs reported lower contrast sensitivity with the multifocal IOL compared with the monofocal IOL. (Data from the 10 RCTs were not pooled because different outcome measures were used in each RCT.)

2.4.2

Pooled data from four RCTs included in the systematic review on the subjective assessment of halos and glare indicate that these symptoms occurred significantly less frequently in patients with monofocal IOLs than in those with multifocal IOLs (OR 3.55, 95%CI 2.11 to 5.96). The non-randomised controlled trial of 102 patients reported that 11% of the multifocal IOL group and 1% of the monofocal IOL group reported glare as a severe symptom (absolute numbers not reported). In the systematic review, two RCTs reported decentration of multifocal IOLs in 8% (3/39) and 12% (3/25) of patients, respectively.

2.4.3

The non-randomised controlled trial of 40 patients reported the need for laser capsulotomy for posterior capsule opacification in 29% (7/24) of patients with bifocal IOLs, 25% (8/32) with multifocal IOLs and 13% (3/24) with accommodating IOLs at 1-year follow-up (level of significance not stated). In the case series of 72 patients (97 eyes) undergoing multifocal IOL implantation, laser capsulotomy for posterior capsule opacification was required in 56% (54/97) of eyes, at a mean follow-up of 34 months after IOL implantation. One patient in this case series had retinal detachment following laser treatment.

2.4.4

In the case series of 72 patients (97 eyes) undergoing multifocal IOL implantation, 1 patient (<1%) required iris fixation at 2-year follow-up. A report of 2 patients described opacification of the multifocal IOL in each patient at 6?8-week follow-up. Another case report described a patient with a paracentral scotoma with significantly reduced acuity at 2-day follow-up.

2.4.5

The Specialist Advisers considered key safety outcomes to include dysphotopsia and the need for replacement of multifocal IOLs with monofocal IOLs. They listed adverse events to include problems with intermediate vision, reduced contrast sensitivity, halos, glare, ?waxy vision? and reduced tolerance to astigmatism.

3	*Further information*
3.1	The Institute has produced guidance on implantation of accommodating IOLs during cataract surgery (www.nice.org.uk/IPG209).

Bruce Campbell
Chairman, Interventional Procedures Advisory Committee
January 2008

Appendix:

Sources of evidence

The following document, which summarises the evidence, was considered by the Interventional Procedures Advisory Committee when making its provisional recommendations.

'Interventional procedure overview of implantation of multi-focal (non-accommodative) intraocular lenses during cataract surgery', November 2007.

Available from: http://www.nice.org.uk/guidance/index.jsp?action=download&o=39048.

This page was last updated: 30 March 2010