Verteporfin photodynamic therapy for neovascular age-related ...

96 Appendix 1more patients in the verteporfin treatment arm than the placebo arm had lost fewerthan 15 letters on the letter chart 24 months after treatment (53% vs 38%; p < 0.001).In a pre-specified subgroup analysis, the TAP trial demonstrated that eyes withcertain subtypes of CNV experienced a greater benefit. Specifically, lesions withclassic and no occult CNV (all of the lesion is classic CNV) or predominantly classicCNV (>50% of the lesion is classic CNV) had a better outcome relative to placebo(59% vs 31% losing fewer than 15 letters; p0.05). However, the differenceincreased by 24 months and was just statistically significant (55% vs 68%respectively ; p=0.03). NICE reviewed the sub-group comparisons andrecommended (a) that patients with lesions with classic and no occult CNV should beoffered PDT treatment in the NHS and (b) that patients with predominantly classiclesions should be treated as part of new clinical studies, such as the VPDT study.After consideration of the evidence, the NICE appraisal team also decided thatalthough the existing trials were supportive of clinical effectiveness in subgroups ofpatients with CNV, benefit in terms of patient-centred outcomes or cost-effectivenesswas lacking. Therefore guidance from NICE has limited the use of PDT to beundertaken within the NHS under specific and defined conditions while additionalevidence on its role and value in the treatment of CNV are acquired [2].The guidance from the 2 nd Final Appraisal Determination (FAD) dated September2003 has been posted on the NICE website and is reproduced in Box 1 below.2.3 Impact of NICE guidance on clinical practiceThe guidance from NICE proposes selection of patients for PDT treatment usingacuity criteria, thus demanding that the clinical assessments are undertaken tospecified standards. It is accepted that routine NHS clinics do not operate to thesestandards and visual function tests that are routinely performed may be unreliable.