Primary Angle-Closure and Angle-Closure Glaucoma

Preface The objective of this book is to offer the general ophthalmologists a clinical comprehensive and practical guidance manual for primary angle-closure and primary angle-closure glaucoma to be used in the daily clinical work. Already in the nineteen seventies our Danish colleague, Poul Helge Alsbirk documented the exceptional high prevalence of angle-closure glaucoma among the Eskimo or Inuit population in Greenland, a North-Atlantic part of Denmark. As Danish ophthalmologists ever since have been responsible for the diagnostics and therapy of primary angle-closure (PAC) and primary angle closure glaucoma (PACG) among these patients, this has led to a profound clinical experience and a growing knowledge of the complicated nature of this entity. We have experienced that the sub-clinical asymptomatic, “creeping” angle closure is a common type and early detection and prevention therefore necessary, just as in open-angle glaucoma. Further that different mechanisms and stages of PAC need different treatments and that a new, more differentiated and objectively based classification and terminology consequently has to be developed. To practice these recommendations we have learnt to use a number of standardised, clinical diagnostic methods. To support the Danish ophthalmologists a guidance manual for primary angle-closure in Danish was published 2003 based on our long clinical experience, the present evidence based literature and conferences on glaucoma. As the guidelines in Danish were very well received we were encouraged to produce an updated English edition. The new evidence about the high prevalence of angle-closure in Asians further supports an English edition. The point that early angle-closure may be cured and the fact that the world-wide visual disability from this disease is almost equivalent to open-angle glaucoma emphasizes the “urgent need” of improving the angle-closure management. The word “glaucoma” is now only used in the presence of structural defects of the optic nerve head or when visual field defects are found. Acknowledgment should be given to our Danish colleagues Poul Helge Alsbirk, Erik Krogh and Lisbeth Serup for their advice and guidance of crucial importance. A special thank goes to Pfizer Denmark, who published the first edition in Danish and sponsored the translation from Danish into English with an unrestricted educational grant. Copenhagen May 2007 Svend Vedel Kessing and John Thygesen Preface By Svend Vedel Kessing and John Thygesen Introduction Aims And Methods Detection of Primary Angle-closure (PAC) Limbal Chamber Depth Measurement (LCD) Methodology Sources of Error Diagnostic Methods in PAC Axial Chamber Depth Measurement (ACD) Methodology Optical Pachymetry Ultrasonic or Laser Based Chamber Depth Measurement Laser Scanning Pachymetry (Visante Oct System) Sources of Error Gonioscopy Introduction Goniolenses and Their Uses Posner’s 4-mirror Indentation Lens Goldmann’s Gonioscopy Lens Gonioscopy Methods with PAC Chamber Angle: Classification and Definitions Standardised PAC Gonioscopy Methodology Start the Examination with the Posner Lens 4-mirror Lens Continuation with Goldmann’s Gonioscopy Lens Gonioscopy Findings Normal Anatomy of the Chamber Angle Glaucoma Pathology in the Chamber Angle Provocation Test Dark-room Test – Prone Position Ultrasound Biomicroscopy (UBM) Main Classification of PAC Introduction Main Classification and Methods of Classification Main Groups and Subclassification of PAC Group I: PAC with Pupil Block Pathophysiology and Pathogenesis Detection and Diagnosis Subclassification with Specific Treatment and Case Histories YAG-laser Iridotomy: Evaluation YAG-laser Iridotomy in General Group II: PAC with Plateau Iris Pathophysiology and Pathogenesis Detection and Diagnosis Subclassification with Specific Treatment and Case Histories Argon-laser Iridoplasty: Evaluation Argon-laser Iridoplasty in General Group III: PAC Mixed Group (I+II) Pathophysiolology and Pathogenesis Detection and Diagnosis Subclassification with Specific Treatment and Case Reports YAG-laser Iridotomy/argon-laser Iridoplasty: Evaluation YAG-laser Iridotomy/argon-laser Iridoplasty In General Treatment Procedures with PAC Principles of Treatment with Acute PAC I, II and III Treatment of Acute PAC I, II and III (Previously “Acute Glaucoma”) YAG-laser Iridotomy Indications Contraindications Technique Argon-laser Iridoplasty Indications Relative Iridoplasty Indications Contraindications Technique Fistulating Operation Indication Complications Prevention of Post-operative Hyperfistulation Post-operative Treatment References Rights of illustrations Index