Interventional procedure consultation document

Corneal inlay implantation for correction of presbyopia

Treating presbyopia by inserting an artificial disc into the cornea

Age-related long-sightedness (presbyopia) develops as the lens in the eye becomes stiffer, making it more difficult to focus on close objects. It is usually corrected with reading glasses or contact lenses. Surgery such as lens replacement may be offered. Corneal inlay implantation is a surgical treatment in which a disc is placed inside a flap or pocket made in the cornea (the transparent layer at the front of the eye). This improves near vision by changing the way in which light passes through the eye.

The National Institute for Health and Clinical Excellence (NICE) is examining corneal inlay implantation for correction of presbyopia 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 inlay implantation for correction of presbyopia.

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 provisional recommendations
• the identification of factual inaccuracies
• additional relevant evidence, with bibliographic references where possible.

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.

• 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• The Advisory Committee will then prepare draft guidance which will be the basis for NICE’s guidance on the use of the procedure in the NHS in England, Wales, Scotland and Northern Ireland.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 NICE website (www.nice.org.uk/ipprogrammemanual).

Through its guidance NICE is committed to promoting race and disability equality, 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 interventional procedures guidance. In particular, we aim to encourage people and organisations from groups who might not normally comment on our guidance to do so.

In order to help us promote equality through our guidance, we should be grateful if you would consider the following question:

Are there any issues that require special attention in light of NICE’s duties to have due regard to the need to eliminate unlawful discrimination and promote equality and foster good relations between people with a characteristic protected by the equalities legislation and others?

Please note that NICE reserves the right to summarise and edit comments received during consultations or not to publish them at all where in the reasonable opinion of NICE, the comments are voluminous, publication would be unlawful or publication would otherwise be inappropriate.

Closing date for comments: 18 January 2013

Target date for publication of guidance: 24 April 2013

1                      Provisional recommendations

1.1                  There is a limited quantity of evidence, predominantly from case series, showing that corneal inlay implantation for correction of presbyopia is efficacious in the short-term. In addition, there are reports that adverse effects occur frequently. Therefore, this procedure should only be used with special arrangements for clinical governance, consent and audit or research.

1.2                  Clinicians wishing to undertake corneal inlay implantation for correction of presbyopia should take the following actions.

• Inform the clinical governance leads in their Trusts.
• Ensure that patients understand that this is principally a cosmetic procedure that may reduce their need to wear spectacles or contact lenses. They should be made aware of other management options for presbyopia. They should be informed about the possible adverse events associated with the procedure and encouraged to balance these carefully against the expected benefits. Patients should be provided with clear written information. In addition, the use of NICE’s information for the public is recommended. [[URL to be added at publication]]
• Audit and review clinical outcomes of all patients having corneal inlay implantation for the correction of presbyopia (see section 3.1).

1.3                  Both clinicians and manufacturers are encouraged to collect details of complications and long-term outcomes following corneal inlay implantation for correction of presbyopia, 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              Presbyopia results from age-related deterioration of the lens in the eye and usually begins to develop at around 40 years of age. This form of lens deterioration causes difficulty with accommodation (focusing on near objects).

2.1.2              Standard treatment for presbyopia is corrective spectacles or contact lenses. Surgery (conductive keratoplasty, monovision or blended-vision laser in situ keratomileusis [LASIK], or refractive lens exchange or replacement) may be considered in some patients.

2.1.3              Corneal inlay implantation is a minimally invasive surgical procedure that aims to improve near visual acuity and increase depth of focus. It may particularly benefit people who find it difficult to use spectacles or contact lenses, for instance those with limited dexterity.

2.2                  Outline of the procedure

2.2.1             The procedure is usually performed on the non-dominant eye. It is done under topical anaesthesia. The patient fixates their eye on a light source on a surgical microscope so that the surgeon can identify the target position on the centre of the visual axis. Laser or microkeratome techniques are used to create either a lamellar corneal flap or a pocket within the corneal stroma. The flap or pocket is separated with a spatula and a special tool is used to position the inlay within it, at the marked centre of the axis. The flap or pocket self-seals, holding the inlay in place. Patients are normally prescribed corticosteroids and antibiotic eye drops in the short term and artificial tears for as long as needed. The inlay can be removed or replaced if needed.

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/guidance/IP/1004/overview

2.3                  Efficacy

2.3.1              A case series of 32 patients reported that mean uncorrected near visual acuity (UNVA) in the treated eye improved from J7/8 preoperatively to J1 at 3 years and the binocular UNVA improved from J6 to J1 (p<0.00001). Mean uncorrected intermediate visual acuity (UIVA) in the treated eye improved from 20/40 to 20/25 at 3 years (p<0.00001); binocular UIVA also improved from 20/32 to 20/20 (p<0.001). Mean uncorrected distance visual acuity (UDVA) in the treated eye decreased slightly from 20/16 to 20/20 at 3 years (p<0.001). The change in binocular UDVA was not statistically significant (p=0.77).

2.3.2               A case series of 39 patients reported an improvement in mean UNVA in the treated eye from 20/50 preoperatively to 20/20 in 22 patients followed up for 4 years (p<0.001). Mean UDVA in the treated eye changed from 20/20 to 20/25 after 4 years (p=0.107).

2.3.3              The case series of 32 patients reported an increase in mean reading speed per minute from 142 words before treatment to 149 words after a mean follow‑up of 2 years (p=0.029). Mean reading distance decreased from 48.1 cm to 38.9 cm (p<0.0001).

2.3.4              The case series of 32 patients reported that the percentage of patients using glasses all or most of the time decreased from 88% to 6% at 3 years (absolute numbers not given).

2.3.5              A case series of 24 patients reported a mean satisfaction with the procedure of 4.9 (on a scale of 1–7 where higher scores show more satisfaction) at 1 year after treatment. Mean satisfaction with reduction in reading glasses was 5.0 in bright light and 3.1 in dim light, using the same scale. It was reported that 75% (18/24) of patients said that they would have the procedure again and 25% (6/24) were undecided (exact question not reported).

2.3.6              The Specialist Advisers listed key efficacy outcomes as improved unaided near or reading vision with maintained distance vision and contrast sensitivity.

2.4                  Safety

2.4.1              Removal of the inlay was reported in 4 patients in the case series of 39 patients because of a buttonhole flap (in 1 patient at 6 weeks), refractive shifts and reported glare and halos (in 2 patients after 3 months) and a thin corneal flap causing symptoms (in 1 patient after 17 months). Following removal of the inlay, visual acuity returned to pretreatment values in all 4 patients.

2.4.2              Inlays were recentred after 6 months because of initial misplacement in 2 patients in the case series of 32 patients. Both patients’ visual acuity for near, intermediate and distance improved after recentration (reported graphically).

2.4.3              Cataracts affecting visual function and needing surgical treatment developed in 5 treated eyes after 3–4 years in the case series of 39 patients.

2.4.4              Loss of visual acuity at 3 years was reported in 14 patients in the case series of 32 patients (2 lines of UDVA were lost by 4 patients, 1 line of CDVA was lost by 9 patients, and 3.8 lines of CDVA were lost by 1 patient).

2.4.5              Flap striae developed in 1 patient after 1 month in the case series of 32 patients, resulting in epithelial ingrowth that needed repeated flap lift and debridement and was resolved by suturing after 2 months.

2.4.6              Hyperopic shifts greater than +0.5 D were measured in 4 patients in the case series of 32 patients at 3 years follow-up. Myopic refractive shifts were also noted in 4 patients.

2.4.7              Severe, moderate and mild halo was reported by 1, 8 and 11 patients respectively in the case series of 32 patients at 3 years. Mild or moderate halo had been reported by 3 patients before treatment. Five patients in the same study reported severe problems with night vision.

2.4.8              A significant decrease in photopic (p<0.001) and mesopic (p<0.0001) contrast sensitivity at all spatial frequencies was reported in the case series of 508 patients at 1 year after treatment.

2.4.9              The Specialist Advisers listed additional theoretical adverse events as infectious keratitis, corneal scarring or opacification, corneal thinning and melting, difficulty measuring intraocular pressure, failure to adapt to near monovision, reduction in unaided distance vision and reduction in best spectacle-corrected distance visual acuity.

2.5                  Other comments

2.5.1              The Committee recognised that although this procedure is usually undertaken for cosmetic reasons, some patients with presbyopia might be unable to use spectacles or contact lenses.

2.5.2              The Committee noted that particular care is needed when obtaining consent from patients with learning disabilities who are considering this procedure.

2.5.3              The Committee recognised that presbyopia is a progressive condition and therefore long-term data on efficacy and safety are important.

2.5.4              The Committee recognised that a number of inlays are available and they may differ in their efficacy and safety.

3                      Further information

3.1                  This guidance requires that clinicians undertaking the procedure make special arrangements for audit. NICE has identified relevant audit criteria and is developing an audit tool (which is for use at local discretion), which will be available when the guidance is published.

3.2                  For related NICE guidance see www.nice.org.uk

Bruce Campbell

Chairman, Interventional Procedures Advisory Committee

December 2012