Verteporfin photodynamic therapy for neovascular age-related ...

DOI: 10.3310/hta16060Health Technology Assessment 2012; Vol. 16: No. 67Chapter 3MethodsStudy designThe VPDT cohort study was designed as a longitudinal treatment register (case series) of allpatients treated with VPDT in the UK. The study received research ethics committee approval(reference MREC/03/11/103).The manual of operations, describing the study design and methods, including standardprotocols for all measurements, was prepared before recruitment started and was updatedperiodically. The final version of this manual (version 2.1, December 2005) is included asAppendix 1.SettingWhen the VPDT cohort study was conceived, VPDT was not widely used in the NHS. LocalSpecialised Commissioning Groups (SCGs) recommended that VPDT should be providedonly in designated ophthalmology departments in NHS hospitals. The Royal College ofOphthalmologists and clinicians involved with the VPDT cohort study took responsibility forproviding a training programme for ophthalmologists and other health-care staff in hospitalsthat were newly implementing the provision of VPDT. Thus, the setting for the study was alldesignated hospitals (DHs) providing VPDT in the NHS.After the majority of DHs had been identified and their personnel had been trained, the studyteam organised meetings of investigators. These meetings described progress with the study,discussed aspects of compliance with the study protocol, data submission and quality, andprovided additional training. This training covered:■■■■■■for participating ophthalmologists, retreatment decision-making and interpretationof angiogramsfor independent grading for ophthalmic photographers and technicians, acquisition ofangiograms and their subsequent submission to the Network of Ophthalmic Reading Centresin the UK (NetwORC UK, see Network of Ophthalmic Reading Centres in the UK)for nurses, optometrists and site co-ordinators, assessment of visual and otherstudy procedures.ParticipantsThe manual of operations described the criteria for eligibility for treatment according to theNICE guidance:■■Best corrected visual acuity in the eye being considered for treatment must be equal to orbetter than Snellen 6/60, approximately equivalent to seeing one or more letters on the linecorresponding to a logarithm of the minimum angle or resolution (logMAR) of 1.0, or > 30© Queen’s Printer and Controller of HMSO 2012. This work was produced by Reeves et al. under the terms of a commissioning contract issued by theSecretary of State for Health.