Photodynamic treatment for macular degeneration

Findings by SBU Alert

Version: 1

Method and target group

Age-related macular degeneration is a disease involving macula in the retina. It is the most common cause of pronounced visual deterioration in individuals over 60 years of age. The most serious form, wet age-related macular degeneration, accounts for 10 percent to 15 percent of the cases and often leads to substantial visual loss. Photodynamic therapy (PDT) using verteporfin (Visudyne) is a new method which increases the opportunity to treat this group of patients for whom no effective treatment method was previously available. In Sweden, an estimated 700 to 1000 patients per year could potentially benefit from this type of treatment.

Patient benefits, complications, and side effects

PDT was compared with placebo in 2 identical multicenter randomized controlled trials involving approximately 600 patients. After two years, 59 percent of the patients had essentially sustained their visual acuity in the PDT eye, compared to 31 percent in the control group. On average, each eye had been treated 5,5 times during the two years. The results from these studies suggest that PDT reduces the risk for substantial visual diminution. During treatment, the individual patient may experience some discomfort due to temporary visual disturbance and hypersensitivity to light.

Economic aspects

No scientific assessments have addressed the cost effectiveness of PDT. Therefore, only a rough estimate can be ventured. The total treatment costs for a single eye are estimated to approximately 80 000 Swedish kronor (SEK). Effects are documented in only about one fourth of the cases, which means that the cost for maintaining visual acuity in one eye is approximately 285 000 SEK. These costs need to be weighed against the benefits for the individual and society. The total expenditure to Swedish health services is estimated to reach 60–80 million SEK per year.

Scientific evidence

There is moderate* scientific documentation concerning patient benefits up to 2 years after treatment. However, there is no* evidence concerning patient benefits in the long term or the cost effectiveness of treatment. Because of the substantial economic consequences, and since there are no data concerning long-term effects and no independent, confirming studies, it is important that patients in Sweden are monitored in a uniform way that allows assessment of the ongoing treatment results.

*This assessment by SBU Alert uses a 4-point scale to grade the quality and evidence of the scientific documentation. The grades indicate: (1) good, (2) moderate, (3) poor, or (4) no scientific evidence on the subject.

This summary is prepared at SBU in collaboration with Assoc. Prof. Magnus Gjötterberg, S:t Erik Hospital, Stockholm and has been reviewed by Assoc. Prof. Birgitta Bauer, Lund University Hospital, Lund.

The full report is available only in Swedish.

Alert is a joint effort by the Swedish Council on Technology Assessment in Health Care (SBU), the Medical Products Agency, the National Board of Health and Welfare, and the Federation of Swedish County Councils.

References

1. Bressler SB and the TAP study group. Photodynamic Therapy of Subfoveal Choroidal Neovascularization in Age-Related Macular Degeneration With Verteporfin: Two-Year Results of 2 Randomized Clinical Trials - TAP Report 2. Arch Ophthalmol. 2001;119:198-207
2. Macular Photocoagulation Study Group. Visual outcome after laser photocoagulation for subfoveal choroidal neovascularisation secondary to age-related macular degeneration: the influence of initial lesion size and initial visual acuity. Arch Ophthalmol. 1994;112:480-488
3. Macular Photocoagulation Study Group. Laser photocoagulation of juxtafoveal choroidal neovascularization: five-year results of randomized clinical trials. Arch Ophthalmol. 1994;112:500-509
4. Photodynamic therapy of subfoveal choroidal neovascularisation in age-related macular degeneration with verteporfin: one-year results of 2 randomized clinical trials. Treatment of age-related macular degeneration with photodynamic therapy (TAP) Study Group. Arch Ophthalmol. 1999;117:1329-1345
5. Schmidt-Erfurt U, Miller JVV, Sickenberg M, et al. Photodynamic therapy with verteporfin for choroidal neovascularisation caused by age-related macular degeneration: results of retreatments in a phase 1 and 2 study. Arch Ophthalmol. 1999;117:1177-1187
6. Visudyne European Public Assessment Report. http://www.eudra.org/humandocs/Humans/EPAR/Visudyne/VisudyneM.htm