The National Institute for Clinical Excellence is examining transpupillary thermotherapy for age-related macular degeneration and will publish guidance on its safety and efficacy to the NHS in England and Wales. The Institute's Interventional Procedures Advisory Committee has considered the available evidence and the views of Specialist Advisors, who are consultants with knowledge of the procedure. The Advisory Committee has made provisional recommendations about transpupillary thermotherapy for age-related macular degeneration.

This document has been prepared for public consultation. It summarises the procedure and sets out the provisional recommendations made by the Advisory Committee.

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 the Final Interventional Procedure Document (FIPD) and submit it to the Institute.
• The FIPD may be used as the basis for the Institute's guidance on the use of the procedure in the NHS in England and Wales.

For further details, see the Interim Guide to the Interventional Procedures Programme, which is available from the Institute's website (www.nice.org.uk/ip).

Closing date for comments: 27 January 2004

Target date for publication of guidance: April 2004

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

Current evidence on the safety and efficacy of transpupillary thermotherapy for age-related macular degeneration does not appear adequate for this procedure to be used without special arrangements for consent and for audit or research.

Clinicians wishing to undertake transpupillary thermotherapy for age-related macular degeneration should:

• inform the clinical governance leads in their Trusts.
• ensure that patients understand the uncertainty about the procedure's safety and efficacy and should provide them with clear written information. Use of the Institute's Information for the Public is recommended
• audit and review clinical outcomes of all patients having transpupillary thermotherapy for age-related macular degeneration. Publication of safety and efficacy outcomes will be useful in reducing the currenty uncertainty. The Institute may review the procedure upon publication of further evidence.

Macular degeneration comprises a group of conditions that affect central vision, and can lead to irreversible blindness. The prevalence of macular degeneration increases with age.

Ninety percent of people with age-related macular degeneration (AMD) have dry (atrophic) macular degeneration, characterised by thinning of the macular retina. The other 10% have wet (exudative or neovascular) macular degeneration, characterised by the growth of abnormal new blood vessels in the choroid layer underneath the retina. These new vessels can leak fluid and cause scarring, which can threaten vision. They can be classified using fluoroscein angiography into 'classic' if they can be seen clearly and 'occult' if they cannot. Wet macular degeneration usually occurs in people who already have dry macular degeneration. Of these two conditions, wet macular degeneration progresses more quickly and vision loss is more severe.

Laser therapy is used to coagulate new vessels in wet macular degeneration. However, the procedure itself may permanently impair vision, especially if the vessels are very close to the fovea (subfoveal vessels). Recurrence is common. Laser therapy appears to work only in people with classic neovascular macular degeneration.

Other new treatments for macular degeneration include surgery to remove new vessels, radiotherapy, photodynamic therapy, and new drugs that suppress new vessel formation (antiangiogenic drugs).

Transpupillary thermotherapy uses laser energy to coagulate vessels in wet macular degeneration and is intended to alter the disease process[A1] and preserve vision. This procedure uses a lower power, more diffuse beam than standard laser treatment. It may be used to treat patients with occult new vessels.

All studies identified were uncontrolled and relatively small with a mean follow-up of no greater than 10 months. The majority of patients in the studies had occult or predominantly occult subfoveal new vessels. Visual acuity improved in 0-32% of cases and deteriorated in 9-43% of cases among the studies identified. For more details, refer to the sources of evidence (see Appendix).

A Specialist Advisor considered that optimal treatment protocols have yet to be established.

The main safety findings reported in the studies reviewed were: large submacular haemorrhage in the first 2 months, 3/49 patients (6%); postoperative haemorrhage, 3/66 patients (5%); and macular infarction, 1/77 patients (1%). For more details, refer to the sources of evidence (see Appendix).

The Specialist Advisors considered there to be a risk of unwanted thermal damage to the retina and pigment epithelium.

The Committee will wait for the results of the current randomised controlled trial (TTT4CNV, co-ordinated at the New England Eye Centre, Tufts University School of Medicine, USA) and reconsider the procedure then.

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

• Interventional Procedure Overview of transpupillary thermotherapy for age-related macular degeneration, December 2002

Available from: www.nice.org.uk/ip061overview