A systematic review of the safety and efficacy of elective photorefractive surgery for the correction of refractive error Alison Murray, Lisa Jones, Anne Milne, Cynthia Fraser, Tania Lourenço, Jennifer Burr April 2005 INTERVENTIONAL PROCEDURES PROGRAMME NATIONAL INSTITUTE FOR HEALTH AND CLINICAL EXCELLENCE REVIEW BODY REPORT Title A systematic review of the safety and efficacy of elective photorefractive surgery for the correction of refractive error. Produced by Health Services Research Unit University of Aberdeen Polwarth Building Foresterhill Aberdeen AB25 2ZD In collaboration with Department of Health Services Research School of Health and Related Research University of Sheffield Regent Court Sheffield S1 4DA The Review Team Alison Murray, Lisa Jones, Anne Milne, Cynthia Fraser, Tania Lourenco, Jennifer Burr Correspondence to Jennifer Burr Clinical Research Fellow Health Services Research Unit University of Aberdeen Polwarth Building Foresterhill Aberdeen AB25 2ZD Tel: (01224) 559715 Fax: (01224) 554580; Email: [email protected] Date completed April 2005 ii ‘ Home units’ details The Health Services Research Unit (HSRU) is a multidisciplinary research group of about 50 people based in the University of Aberdeen. The Unit is core-funded by the Chief Scientist Office of the Scottish Executive Health Department, and has responsibility for the following general remit: 1. To study or evaluate clinical activities with a view to improving effectiveness and efficiency in health care; 2. To work for the implementation of proven changes in clinical activities; 3. To encourage and support similar work thoughout Scotland; 4. To train NHS staff in Scotland, and others, in the principles and practice of health services research in general, and health care evaluation in particular. The Unit has an established portfolio of health services research focusing on two main programmes – health care assessment and delivery of care. The Unit is one of the three research groups that make up the ‘Review Body’ for the National Institute for Clinical Excellence Interventional Procedures Programme. The other is based at the University of Sheffield in the School of Health and Related Research (ScHARR). ScHARR brings together a wide range of health related skills including: health economics, operational research, management sciences, epidemiology, medical statistics, and information science. There are also clinical skills in general practice and primary care, psychiatry, rehabilitation and public health. ScHARR employs about 200 multidisciplinary staff and attracts in excess of £4 million per year in external support. ScHARR is organised into seven sections, including the Health Services Research Section, which consists of four academic groups covering research into acute and critical care, complementary medicine, primary care, long-term conditions, emergency and immediate care, and social sciences and health. Contributions of authors Alison Murray commented on the scope, screened the LASIK search results, assessed full text LASIK papers for inclusion, undertook data abstraction and quality assessment of LASIK studies, drafted the methods and LASIK sections of the review, and contributed to the writing of the rest of the review. Lisa Jones screened the PRK search results, assessed full text PRK papers for inclusion, undertook data abstraction and quality iii assessment of PRK studies, drafted the PRK section of the review, and contributed to the writing of the rest of the review. Anne Milne screened LASEK search results, assessed full text LASEK papers for inclusion, undertook data abstraction and quality assessment of the LASEK studies, drafted the LASEK sections of the review, and contributed to the writing of the rest of the review. Cynthia Fraser developed and ran the literature search strategies, obtained papers and formatted the references. Tania Lourenco contributed to writing the background, unpublished data, quality assessment and appendices. Jennifer Burr wrote the scope for the review and the conclusions, contributed to writing the background, discussion, unpublished data and executive summary, commented on the rest of the review and provided a clinical oversight. Conflict of interest None Acknowledgements We thank Bruce Allan (Consultant Ophthalmic Surgeon, Moorfields Eye Hospital), Paul Rosen (Consultant Ophthalmic Surgeon, Oxford Eye Hospital and President Elect of the UK and Ireland Society of Cataract and Refractive Surgeons) and Catharine Chisholm (Research Fellow, Applied Vision Research Centre, City University London and Vice President of the British Society for Refractive Surgery) for providing specialist advice and commenting on the draft of the report, Adrian Grant (Director, HSRU) and Brian Ferguson (Univerisity of York) for commenting on the draft of the report, Bronwyn Davidson (Reviews Secretary, HSRU) and Kathleen McIntosh (Senior Secretary, HSRU) for helping to format the manuscript and Jonathan Cook for assistance with statistical analysis. The Health Services Research Unit receives a core grant from the Scottish Executive Health Department. The views expressed are those of the authors and not necessarily those of the funding bodies. Special thanks also go to Bruce Allan, Dr H Hashemi, Dr M Camellin and Dr P Condon for providing additional information for published studies and Dan Reinstein (London Vision Clinic) for providing unpublished data. iv TABLE OF CONTENTS Executive summary xv List of abbreviations xx Glossary xxi 1 OBJECTIVE OF THE REVIEW 1 2 BACKGROUND 2 2.1 Description of the underlying condition 2 2.1.1 Refractive errors 2 2.1.2 Current management and alternative procedures 3 2.2 The interventional procedures under review 5 2.2.1 Candidate assessment 5 2.2.2 The Laser 6 2.2.3 Photorefractive keratectomy (PRK) 7 2.2.4 Laser Epithelial Keratomileusis (LASEK) 8 2.2.5 Laser-in-situ Keratomileusis (LASIK) 9 2.3 Personnel involved (eg. surgeons, anaesthetists, nurses) and 11 skill/experience required 2.4 Current use in the UK (including existing guidance) 11 3 METHODS FOR REVIEWING EVIDENCE ON EFFICACY AND 13 SAFETY 3.1 Search strategy 13 3.2 Inclusion and exclusion criteria 14 3.2.1 Types of studies 14 v 3.2.2 Types of participants 15 3.2.3 Types of intervention 15 3.2.4 Types of outcomes 16 3.3 Quality assessment strategy 16 3.4 Data extraction strategy 17 3.5 Data analysis 17 3.6 Unpublished data 18 3.7 Included studies 18 4 PRK RESULTS 19 4.1 Type and quantity of available evidence 19 4.2 Number and type of included studies 19 4.2.1 Myopia 19 4.2.2 Hyperopia 20 4.2.3 Astigmatism 21 4.3 Number and type of excluded studies 22 4.4 Quality of available evidence 22 4.5 Overview of safety findings 26 4.5.1 Myopia 26 4.5.2 Hyperopia 32 4.5.3 Astigmatism 35 4.6 Overview of efficacy findings 37 4.6.1 Myopia 37 4.6.2 Hyperopia 41 4.6.3 Astigmatism 44 vi 5 LASEK RESULTS 47 5.1 Type and quantity of available evidence 47 5.2 Number and type of included studies 47 5.3 Number and type of excluded studies 51 5.4 Quality of available evidence 51 5.5 Overview of safety findings 52 5.5.1 Potentially serious complications 52 5.5.2 Undesired consequences 53 5.6 Overview of efficacy findings 57 5.6.1 Accuracy 57 5.6.2 Uncorrected visual acuity (UCVA) 59 6 LASIK RESULTS 62 6.1 Type and quantity of available evidence 62 6.2 Number and type of included studies 62 6.3 Number and type of excluded studies 67 6.4 Quality of available evidence 67 6.5 Overview of safety findings 69 6.5.1 Keratomileusis-related complications 69 6.5.2 Potentially serious complications 75 6.5.3 Undesired consequences 78 6.6 Overview of efficacy findings 84 6.6.1 Myopia and myopic astigmatism 84 6.6.2 Hyperopia, hyperopic astigmatism and mixed astigmatism 87 6.6.3 Astigmatism 89 6.6.4 Retreatments 90 vii 6.7 Unpublished data 92 6.7.1 Safety 92 6.7.2 Efficacy 94 7 EVIDENCE FROM RCTS COMPARING PRK, LASEK AND LASIK 97 7.1 Type and quantity of available evidence 97 7.2 Number and type of included studies 97 7.3 Number and type of excluded studies; reasons for exclusion 99 7.4 Quality of available evidence 99 7.5 Overview of safety findings 101 7.5.1 LASEK versus PRK safety findings 101 7.5.2 LASEK versus LASIK safety findings 103 7.5.3 LASIK versus PRK safety findings 105 7.6 Overview of efficacy findings 107 7.6.1 LASEK versus PRK efficacy findings 107 7.6.2 LASEK versus LASIK efficacy findings 108 7.6.3 LASIK verus PRK efficacy findings 109 8 DISCUSSION 110 8.1 Assumptions, limitations and uncertainties 110 8.2 Safety 113 8.2.1 Ectasia 113 8.2.2 Loss of Best Spectacle Corrected Visual Acuity (BSCVA) 114 8.2.3 Inflammation 115 8.2.4 Flap complications 116 8.2.5 Epithelial complications 117 viii 8.2.6 Post-operative quality of vision 118 8.2.7 Vitreo-retinal complications 120 8.2.8 Risk of developing glaucoma after photorefractive surgery 121 8.2.9 Other safety considerations 121 8.3 Efficacy 123 8.3.1 Accuracy 123 8.3.2 Post-operative uncorrected visual acuity (UCVA) 125 9 CONCLUSIONS 127 9.1 Safety 127 9.2 Efficacy 128 9.3 Patient selection 129 10 NEED FOR FURTHER AUDIT OR RESEARCH 130 11 REFERENCE LIST 132 ix LIST OF APPENDICES Appendix 1 Search strategy 150 Appendix 2 Checklist of quality assessment of non-randomised studies 159 evaluating interventional procedures Appendix 3 Checklist of quality assessment of randomised controlled trials of 160 an interventional procedure Appendix 4 Included Studies 161 Appendix 5 Characteristics of included studies: PRK case series 174 Appendix 6 Detailed quality assessment results for included PRK case series 229 Appendix