Foreword 1
Foreword 2
Preface
Contents
Contributors
1: Visual Acuity: High Contrast and Low Contrast
1.1 Introduction
1.2 History
1.2.1 Visual Acuity Tools
1.2.2 Contrast Sensitivity Tools
1.3 Underlying Concept
1.3.1 Distance Visual Acuity
1.3.2 Near Visual Acuity
1.3.3 Contrast
1.3.3.1 Low-Contrast Visual Acuity
1.3.3.2 Contrast Sensitivity Function and Contrast Sensitivity
1.4 Technique
1.4.1 Measuring Acuity in Individuals with Vision Impairment
1.4.2 Measuring Visual Acuity in Children
1.4.3 Measuring Near Visual Acuity
1.4.4 Contrast Acuity and Contrast Sensitivity
1.5 Conclusion
References
2: Autorefraction: Objective Estimation of Refractive Error
2.1 Introduction
2.2 Technology
2.2.1 Measurement Principle of Autorefractors
2.2.2 Relative Advantages/Disadvantages of Different Autorefractors
2.3 Clinical Applications
2.3.1 Accuracy and Precision Considerations
2.3.2 Legitimate Representation of Sphero-Cylindrical Refraction
2.3.3 Impact of Measurement Wavelength on the Accuracy of Autorefraction
2.4 Technique
2.4.1 General Guidelines for Obtaining Measurements Using Autorefractors
2.5 Can Autorefractors Replace Retinoscopy in Clinical Practice?
2.6 Conclusions
References
3: Retinoscopy
3.1 Introduction
3.2 History
3.3 Equipment
3.3.1 Retinoscope
3.3.2 Description of a Streak Retinoscope (Fig. 3.1)
3.3.3 Trial Lens Set/Phoropter
3.4 Basic Principles
3.5 Essentials of Retinoscopy
3.5.1 Reflex
3.5.2 Endpoint of Retinoscopy
3.5.3 Astigmatism
3.5.4 Alignment
3.5.5 Controlling Accommodation
3.5.6 Ambient Light
3.5.7 Use of Brightness Controls
3.5.8 Working Distance and Spherical Errors in Retinoscopy
3.6 Estimation of Refractive Errors
3.6.1 When the Observation Is an âAgainstâ Movement of the Reflex
3.6.2 When the Observation Is a âwithâ Movement of the Reflex
3.6.3 Estimating and Confirming the Axis of Astigmatic Error
3.6.4 Finalizing the Magnitude of Astigmatism
3.7 Tips for Performing Retinoscopy (Table 3.3)
3.8 Special Techniques
3.8.1 Cycloplegic and Mohindra Retinoscopy
3.9 Additional Observations
3.10 Comparison Between Autorefraction and Retinoscopy
3.11 Conclusion
References
4: Prescribing Spectacles
4.1 Introduction
4.2 Background
4.3 Principle
4.4 Technique
4.4.1 Spherical Correction
4.4.2 Cylindrical Correction
4.4.3 Jacksonâs Cross Cylinder (JCC) Technique
4.4.4 Astigmatic Fan and Stenopic Slit
4.4.5 Duochrome Test
4.4.6 Binocular Balancing
4.5 Anisometropia
4.6 Presbyopia Correction
4.7 Conclusion
References
5: Optical Dispensing
5.1 Introduction
5.2 Tools, Devices, Machines, and Instruments in Optical Dispensing
5.3 Manual Lensometer
5.3.1 Guide to Using a Lensometer
5.3.2 Important Notes
5.4 Geneva Lens Measure
5.4.1 GLM Calibration
5.4.2 Power Determination
5.5 Thickness CaliperâMeasuring Lens Thickness
5.5.1 Calibration of the Thickness Caliper
5.5.2 Measuring Thickness
5.6 PolariscopeâDetecting Internal Stress in Transparent Materials
5.6.1 Procedure for Using the Polariscope
5.6.2 Interpreting Patterns and Colors
5.6.3 Analysis and Evaluation
5.7 Corneal Reflex PupillometerâMeasuring Pupillary Distance
5.7.1 Measuring Pupillary Distance (PD)
5.8 Conclusion
References
6: Extraocular Muscle Tests and Cover Tests
6.1 Introduction
6.2 History
6.3 Technology
6.4 Technique
6.4.1 Motility and Versions
6.4.2 Ductions
6.4.3 Ocular Alignment
6.4.3.1 Tests Based on the Light Reflex
6.4.3.2 Cover Tests
6.4.4 Vergence Testing
6.4.4.1 Near Point of Convergence
6.4.4.2 Fusional Vergence Ranges
6.4.4.2.1 Horizontal Vergence
6.4.4.2.2 Vertical Ranges
6.4.4.3 Efficiency of the Vergence System
6.5 Clinical Application and Interpretation
6.6 Conclusion
References
7: The Pupil and Pupillary Reflexes
7.1 Introduction
7.2 Pupil Size Measurement
7.2.1 Clinical Examination and Interpretation of Anisocoria
7.2.2 Pharmacological Tests for Abnormal Pupils
7.2.3 Examination of Pupillary Dilation
7.3 Pupillary Light Reflex Examination
7.3.1 Interpretation of Pupillary Light Reflexes and Swinging Flashlight Test
7.4 Near Response
7.4.1 Light Near Dissociation
7.5 Slit Lamp Examination of the Pupil
7.6 Other Pupillary Phenomena
7.7 Conclusion
References
8: Clinical Measurement of Stereoacuity
8.1 Introduction
8.2 History
8.3 Types of Stereopsis Tests
8.4 Neurophysiology of Stereopsis
8.5 Advantages of Stereopsis
8.6 Clinical Usefulness of Stereoacuity Measurements
8.7 Technique
8.7.1 General Clinical Instructions for Stereoacuity Testing with Common Static Stereotests
8.7.2 Specific Aspects of Clinical Stereoacuity Testing
8.8 Advancing Technology
8.9 Summary of Clinical Application and Interpretation
8.10 Conclusion
References
9: Color Vision
9.1 Introduction
9.2 History
9.3 Principles of Color Vision and Its Testing
9.4 Types of Color Vision Deficiencies
9.5 Tests for Color Vision Deficiency
9.5.1 Pseudoisochromatic Test Design Pattern
9.5.1.1 Ishihara Plates
9.5.1.2 HRR Plates
9.5.1.3 General instructions for the usage of Pseudoisochromatic plates
9.5.1.4 Patient Instructions and Procedure
9.5.2 Color Arrangement Tests
9.5.2.1 FM 100 Hue Test
9.5.2.2 D15 Test
9.5.3 Color Matching
9.5.3.1 Anomaloscope
9.5.4 Threshold-Based Digital Color Vision Tests
9.5.4.1 CAD Test
9.5.4.2 Procedure
9.5.4.3 Rabin Cone Contrast Test
9.5.4.4 Cambridge Color Test
9.6 Acquired Color Vision Deficiency
9.7 Conclusions
References
10: Smartphone-Based Ophthalmic Imaging
10.1 Introduction
10.2 A Brief History of Smartphone-Based Ophthalmic Devices: Evolution of Technology
10.3 Fundus Imaging
10.3.1 Fundus on Phone (FOP) and Non-mydriatic Fundus on Phone (FOP NM)
10.3.2 Vistaro
10.4 Anterior Segment Imaging
10.4.1 Digitizing Analog Slit Lamps
10.4.1.1 Anterior Imaging Module (AIM)
10.4.2 Portable Slit Lamps Based on Smartphones
10.4.2.1 PSL D20
10.5 Artificial Intelligence in Smartphone-Based Ophthalmic Imaging Devices
10.6 Smartphone-Based Microscope Video Recording
10.6.1 Microscope Recording Device (MRD)
10.7 Virtual Reality (VR)-Based Visual Field Perimeter
10.8 Conclusion
References
11: Cataract Grading Systems
11.1 Introduction
11.2 History
11.3 Lens Opacification Classification System
11.3.1 Development of LOCS
11.3.2 LOCS III in Clinical Practice (Fig. 11.1)
11.3.3 Surgical Implications of LOCS III
11.3.4 Limitations of LOCS III
11.4 Other Methods of Classification
11.4.1 Slit Lamp Based
11.4.2 Using Retinal Images
11.4.3 Using Other Imaging Modalities
11.4.4 Deep Learning Artificial Intelligence in Cataract Classification
11.5 Conclusion
References
12: Biometry and Intraocular Lens Power Calculation
12.1 Introduction
12.2 Biometry
12.2.1 Types of Biometry
12.2.1.1 Ultrasound Biometry
12.2.1.2 Optical Biometry
12.2.1.3 Newer Technologies in Biometry
12.2.1.3.1 IOL Master 500 (Carl Zeiss Meditec AG, Jena, Germany)
12.2.1.3.2 IOL Master 700 (Carl Zeiss Meditec AG, Jena, Germany)
12.2.1.3.3 AL-Scan (Nidek, Gamagori, Japan)
12.2.1.3.4 Aladdin Ocular Biometer (Topcon, Tokyo, Japan)
12.2.1.3.5 Galilei G6 Dual Scheimpflug Analyzer (Ziemer, Port, Switzerland)
12.2.1.3.6 Eyestar 900 (Haag Streit, Koeniz, Switzerland)
12.2.1.3.7 Argos Advanced Optical Biometer (Movu, Santa Clara, CA)
12.2.1.3.8 OA-2000 (Tomey, GmbH, Nurnberg, Germany)
12.3 IOL Power Calculation Formulae
12.3.1 Classification of Different Formulae for Calculating the Power for IOLs
12.4 Newer Formulae
12.5 Special Circumstances
12.5.1 Aphakia
12.5.2 Pseudophakia
12.5.3 Keratoconus
12.5.3.1 The Kane Formula [21]
12.5.3.2 The Barrett True K Formula for Keratoconus [22]
12.5.4 Pediatric Cataracts
12.5.5 Eyes with Silicone Oil
12.5.6 Calculation of the IOL Power After Refractive Surgery
12.5.6.1 Clinical History Method
12.5.6.2 Contact Lens Over-Refraction Method
12.5.6.3 Topography-Based Post-LASIK Adjusted Keratometry
12.5.7 Piggyback IOLs
12.5.8 High Myopia
12.5.9 Toric IOL
12.6 Errors in Iol Power Calculation
12.7 Techniques Used in IOL Power Measurement
12.7.1 Ultrasound Biometry Must Be Performed by Following These Steps
12.7.2 Optical Biometry Must Be Performed by Following These Steps
12.8 Conclusion
References
13: Imaging in Cataract
13.1 Introduction
13.2 Aberrometry (iTRACE, Tracey Technologies, Houston, TX)
13.2.1 Principle of the iTrace
13.2.2 Image Acquisition Technique
13.2.3 Clinical Applications
13.2.3.1 Localization of the Origin of the Aberration
13.2.3.2 Selecting Spherical vs. Aspherical IOL [3, 9]
13.2.3.3 Preoperative Assessments for Premium IOLs [11, 12]
13.2.3.3.1 Measurement of Higher Order Aberrations (HOAs)
13.2.3.3.2 Measurement of Angle Kappa and Angle Alpha
13.2.3.3.3 Planning for Toric IOLs [13]
13.2.3.4 Dysfunctional Lens Index (DLI)
13.3 Scheimpflug Imaging (OCULUS PentacamÂŽ)
13.3.1 Principle of Scheimpflug Imaging
13.3.2 Image Acquisition
13.3.3 Clinical Applications
13.3.3.1 Preoperative Adjustment of Phacoemulsification Parameters
13.3.3.2 Traumatic Cataract
13.4 Anterior Segment Optical Coherence Tomography (AS-OCT)
13.4.1 Principle of the AS-OCT
13.4.2 Image Acquisition
13.4.3 Clinical Applications
13.4.3.1 Early Cataract
13.4.3.2 Posterior Sub-capsular Cataract (PSC)
13.4.3.3 Mature/Hypermature/White Cataracts
13.4.3.4 Posterior Polar Cataract (PPC)
13.4.3.5 Traumatic Cataracts
13.5 Ultrasound B-Scan
13.5.1 Principle
13.5.2 Image Acquisition [45]
13.5.3 Clinical Applications
13.5.3.1 Detection of Posterior Segment Pathology
13.5.3.2 Detection of Zonular Weakness and Posterior Capsule Breach
13.5.3.3 Intralenticular Foreign Bodies
13.6 Conclusion
References
14: Slit Lamp Biomicroscopy
14.1 Introduction
14.2 History
14.3 Parts of a Slit Lamp
14.3.1 The Illumination Unit
14.3.2 Observer System
14.3.3 The Mechanical System
14.4 Machine Specifications
14.5 Examination Techniques
14.5.1 Direct Illumination
14.5.2 Indirect Illumination
14.6 Stepwise Procedure of Examination
14.7 Slit Lamps Accessories
14.8 Recent Advances and Future Directions
14.9 Conclusion
References
15: Corneal Topography
15.1 Introduction
15.2 History
15.3 Principles and Technology
15.3.1 Reflection-Based Systems
15.3.2 Slit Scanning System
15.3.3 Scheimpflug Imaging
15.4 Color Coding Systems
15.5 Concept of Best-Fit Sphere
15.6 Topography Maps
15.6.1 Keratometry Maps
15.6.1.1 Axial Curvature Maps
15.6.1.2 Tangential Maps
15.6.2 Pachymetry Maps
15.6.3 Elevation Maps
15.7 Interpretation of Maps
15.7.1 Orbscan
15.7.1.1 Rousch Criteria [15]
15.7.2 Pentacam
15.7.2.1 Red Flag Signs of Ectasia on Pentacam Map
15.8 Applications of Corneal Topography
15.9 Conclusion
References
16: Ocular Surface Examination
16.1 Introduction
16.2 Cornea and Conjunctiva
16.2.1 Cornea
16.2.2 Limbus
16.2.3 Conjunctiva
16.3 Ocular Adnexa
16.3.1 Eyelid and Eyelid Margin
16.3.2 Eyelashes
16.3.3 Periocular Skin
16.3.4 Lacrimal Gland
16.3.5 Meibomian Gland
16.4 Tear Film Assessment
16.5 Conclusion
References
17: Intraocular Pressure
17.1 Introduction
17.2 Goldmann Applanation Tonometry (GAT)
17.3 Dynamic Contour Tonometry
17.4 Ocular Response Analyzer (ORA)
17.5 Telemetric 24-h IOP Monitoring
17.5.1 Clinical Application of Telemetric IOP Monitoring
17.6 Rebound Tonometer
17.7 Corvis ST
17.8 Tono-Pen
17.9 Schiotz Tonometry in Todayâs Practice
17.10 Bioresonator Applanation Resonance Tonometer (ART)
17.11 Conclusion
References
18: Gonioscopy
18.1 Introduction
18.2 The Optics of Gonioscopy and Lenses Used
18.3 Techniques Used in Gonioscopy
18.3.1 Indirect Lenses
18.3.2 Direct Lenses
18.4 Structures Seen on Gonioscopy
18.5 Identifying Occludability
18.6 Look Beyond What You See
18.7 Systems for Automated Goniophotography
18.8 Technological Adjuncts to Gonioscopy
18.9 Gonioscopy and Using Artificial Intelligence
18.10 Conclusion
References
19: Optic Disc Photography
19.1 Introduction
19.2 History of Ophthalmic Photography
19.3 Optic Nerve Photography
19.3.1 Monoscopic Color Fundus Photography
19.3.2 Red-Free Photography
19.3.3 Stereoscopic Images
19.4 Retinal Camera for Optic Disc Photography
19.4.1 Non-mydriatic Fundus Cameras
19.4.2 Handheld Fundus Cameras
19.5 Technology Assessment
19.6 Deep Learning-Based Enhanced Optic Disc Photography
19.6.1 AI Framework
19.7 Conclusion
References
20: OCT in Glaucoma
20.1 Introduction
20.2 Technology
20.2.1 Time-Domain OCT
20.2.2 Spectral-Domain OCT
20.2.3 Swept-Source OCT
20.3 Clinical Utility of OCT in Glaucoma
20.3.1 Glaucoma Diagnosis
20.3.2 Glaucoma Progression
20.4 New Advances in Glaucoma OCT
20.4.1 Adaptive Optics in OCT
20.4.2 Enhanced Depth Imaging and Artificial Intelligence Application in OCT Glaucoma
20.4.2.1 Principle
20.4.2.2 Clinical Applicability of EDI Imaging on OCT
20.5 Artificial Intelligence (AI) Applications in Glaucoma OCT
20.6 Conclusion
References
21: Visual Field
21.1 Introduction
21.2 History
21.3 Current Test
21.4 Technique of Humphry Visual Field (HVF) Tests
21.5 Technology
21.5.1 Visual Field Index (VFI)
21.5.1.1 Clinical Application
21.5.2 Central Field Index (CFI)
21.5.2.1 Clinical Application
21.5.3 Swedish Interactive Thresholding Algorithm (SITA) Faster
21.5.3.1 Clinical Application
21.5.4 The 24-2C SITA Faster Algorithm
21.5.5 Technology
21.5.5.1 Clinical Application
21.6 Recent Advances in Octopus Perimetry
21.7 Home-Based Portable Perimeter
21.7.1 Tablet-Based or iPad-Based Perimetry
21.7.2 Laptop-Based Perimetry
21.7.2.1 Clinical Applications
21.7.2.2 Head-Mounted or VR Technology
21.8 Artificial Intelligence (AI) in Visual Field Measurement
21.8.1 Pros and Cons of AI for Visual Field in Glaucoma
21.9 Pediatric Perimetry
21.9.1 The Future of Visual Field Testing
References
22: Retinal Nerve Fiber Layer
22.1 Introduction
22.2 History
22.3 Revisiting RNFL Anatomy and New Insights from Technology
22.3.1 Organization
22.3.2 Topographic Localization and its Relevance in Glaucoma
22.4 Techniques of RNFL Detection and Quantification
22.4.1 Fundus Slit Lamp Biomicroscopy
22.4.2 Fundus Photography
22.4.3 Optical Coherence Tomography (OCT)
22.4.4 Scanning Laser Polarimetry (SLP)
22.4.5 Confocal Scanning Laser Ophthalmoscopy (CSLO)
22.5 Artificial Intelligence-Based Early RNFL Defect Methodologies
22.5.1 Recurrent Neural Network (RNN)
22.5.2 Contrast-Limited Adaptive Histogram Equalization (CLAHE) [35]
22.5.3 Deep Convolutional Neural Network (CNN)
22.5.4 Attention-Based Convolutional Neural Network (AG-CNN) [37]
22.5.5 Conditional Adversarial Shuffle U-Shaped Network (CASU-Net) [38]
22.5.6 Alternative Methods
22.5.6.1 Position-Consistent Data Pre-processing and a Position-Guided Network [39]
22.6 Random Forest and Gray Level Co-occurrence Matrix (GLCM) [41]
22.7 Conclusion
References
23: Ultrasound Biomicroscopy
23.1 Introduction
23.2 History
23.3 Technology
23.3.1 Scanner Design
23.3.2 Transducers
23.3.3 Scan Acquisition
23.4 Technique
23.5 Clinical Applications of Ultrasound Biomicroscopy
23.5.1 Ocular Surface
23.5.2 Cornea
23.5.3 Sclera
23.5.4 Lens and Zonules
23.5.5 Glaucoma
23.5.5.1 Angle Closure Disease
23.5.5.2 Secondary Open-Angle Glaucoma
23.5.5.2.1 Quantitative Measurements
23.5.5.2.2 Glaucoma Surgery
23.6 Uveitis
23.7 Vitreo Retinal Surgery
23.8 Intraocular Tumors
23.8.1 Iris and Ciliary Body Cysts
23.8.2 Uveal Mass Lesions
23.8.3 Ciliary Body Melanoma
23.8.4 Retinoblastoma
23.9 Conclusion
References
24: Ophthalmic Ultrasound
24.1 Physics
24.2 Technique
24.2.1 Probe Positions
24.2.2 Performing the Scans
24.2.2.1 Axial Scan
24.2.2.2 Transverse Scan
24.2.2.3 Longitudinal Scans
24.2.3 Limbus to Fornix Approach
24.2.4 Special Examination Techniques
24.3 Indications
24.4 Clinical Applications
24.4.1 Anatomy of a Normal Ultrasound (Fig. 24.1)
24.4.2 Asteroid Hyalosis (Fig. 24.1)
24.4.3 Vitreous Hemorrhage (Fig. 24.1)
24.4.4 Posterior Vitreous Detachment (Fig. 24.1)
24.4.5 Retinal Detachment (Fig. 24.2)
24.4.6 Tractional RD (Fig. 24.2)
24.4.7 Exudative RD (Fig. 24.3)
24.4.8 Choroidal Detachment (CD) (Fig. 24.3)
24.4.9 Retinoschisis
24.4.10 Retinal Tear
24.4.11 Endophthalmitis/Panophthalmitis (Fig. 24.4)
24.4.12 Vogt-Koyanagi Harada Syndrome (Fig. 24.4)
24.4.13 Posterior Scleritis
24.4.14 Cysticercosis (Fig. 24.5)
24.4.15 Choroidal Coloboma (Fig. 24.5)
24.4.16 Posterior Staphyloma (Fig. 24.5)
24.4.17 Phthisis Bulbi
24.4.18 Trauma
24.4.18.1 Dislocated Crystalline Lens/Intraocular Lens (Fig. 24.6)
24.4.18.2 Intraocular Foreign Body (IOFB) (Fig. 24.6)
24.4.18.3 Optic Nerve Head Avulsion
24.4.18.4 Scleral Rupture (Fig. 24.6)
24.4.19 Tumors
24.4.19.1 Retinoblastoma (Fig. 24.7)
24.4.19.2 Choroidal Melanoma (Fig. 24.7)
24.4.20 Pediatric Retinal Disease
24.4.20.1 Retinopathy of Prematurity (ROP) (Fig. 24.8)
24.4.20.2 Coats Disease
24.4.20.3 Persistence of Fetal Vasculature (PFV)
24.4.21 Silicon Oil-Filled Eye (Fig. 24.9)
24.4.22 Common Optic Nerve Lesions
24.4.22.1 Papilledema
24.4.22.2 Optic Disc Cupping
24.4.22.3 Optic Disc Drusen (Fig. 24.10)
24.5 Conclusion
References
25: Fundus Photography
25.1 Introduction
25.2 History
25.3 Technology
25.3.1 Optics of Fundus Photography
25.3.2 Advances in Image Capture
25.3.2.1 Digital Imaging
25.3.2.2 Confocal Scanning Laser Ophthalmoscope
25.3.2.3 Adaptive Optics SLO
25.3.2.4 Wide-Field and Ultra-wide Field Imaging
25.3.3 Examples of Available Fundus Cameras (Table 25.2; Fig. 25.2)
25.3.4 Artifacts in Fundus Photography and Actions to Prevent These
25.4 Types of Photography
25.4.1 Monochromatic Retinal Photography
25.4.2 Autofluorescence: Blue, Green, and Near-Infrared
25.4.3 Multi-color Imaging
25.4.4 Retro-mode Imaging
25.5 Techniques
25.5.1 Stereophotography
25.6 Clinical Application and Interpretation
25.6.1 Age-Related Macular Degeneration
25.6.2 Polypoidal Choroidal Vasculopathy (PCV)
25.6.3 Central Serous Chorioretinopathy
25.6.4 Macular Dystrophies
25.6.4.1 Stargardt Disease
25.6.4.2 Best Disease
25.6.4.3 Retinitis Pigmentosa (RP)
25.6.4.4 Fundus Albipunctatus
25.6.4.5 Choroideremia
25.6.5 White Dot Syndromes
25.6.5.1 Multiple Evanescent White Dot Syndrome (MEWDS)
25.6.5.2 Punctate Inner Choroidopathy (PIC)
25.6.6 Drug Toxicity
25.6.7 Vascular Retinopathy
25.6.7.1 Diabetic Retinopathy (DR)
25.6.7.2 Retinal Vascular Occlusion
25.6.8 Miscellaneous Retinal Lesions
25.6.8.1 Macular Hole
25.6.8.2 Macular Telangiectasia Type 2
25.6.8.3 Epiretinal Membrane
25.6.8.4 Angioid Streaks
25.6.8.5 Retinochoroidal Colobomas
25.6.8.6 Myelinated Nerve Fibers (MNF)
25.6.8.7 Choroidal Disorders
25.6.9 Optic Nerve Head Disorders
25.6.10 Pathologic Myopia
25.7 Conclusion
References
26: Dye-Based Angiography
26.1 Introduction
26.2 Fundus Fluorescein Angiography
26.2.1 History
26.2.2 Technology
26.2.2.1 Basic Principle
26.2.2.2 Sodium Fluorescein
26.2.2.3 Imaging
26.2.2.4 Stereo Photography
26.2.2.5 Camera and Ancillary Equipment
26.2.2.6 Confocal Scanning Laser Ophthalmoscope
26.2.3 Techniques
26.2.3.1 Fundus Fluorescein Angiography
26.2.3.2 Side Effects and Complications
26.2.3.3 Contraindications
26.2.4 Clinical Application and Interpretation
26.2.4.1 Basic Anatomical Considerations
26.2.4.2 Normal Fluorescein Angiography
26.2.4.3 Abnormal Fluorescence Angiography
26.3 Indocyanine Green Angiography
26.3.1 Technology
26.3.1.1 Properties of Indocyanine Green
26.3.1.2 Toxicity
26.3.1.3 Instrument
26.3.2 Techniques
26.3.2.1 Injection Technique
26.3.2.2 Normal Phases of ICGA
26.3.3 Clinical Application and Interpretation of Indocyanine Green Angiography
26.3.3.1 Age-Related Macular Degeneration (AMD)
26.3.3.2 Polypoidal Choroidal Vasculopathy (PCV) or Aneurysmal Type 1 MNV
26.3.3.3 Pachychoroid Disease Spectrum
26.3.3.4 Choroidal Tumors
26.3.3.5 Varix of the Vortex Vein Ampulla
26.3.3.6 Choroidal Inflammation
26.4 Conclusions
References
27: Paediatric Wide-Field Retinal Imaging
27.1 Introduction
27.2 History and Stages of ROP
27.3 Wide-Angle Imaging Technology
27.3.1 Currently Available Wide-Angle Cameras
27.4 Technology
27.4.1 Optical Design of Imaging System
27.4.2 Understanding of Field of View
27.4.3 Illumination System of Wide-Angle Cameras
27.4.3.1 Trans-pupillary Illumination System
27.4.3.2 Trans-scleral Illumination
27.4.4 Fluorescein Angiography
27.4.5 Image Sensors
27.5 Imaging Technique
27.6 Clinical Application
27.7 Conclusion
References
28: Optical Coherence Tomography and Optical Coherence Tomography-Angiography
28.1 Introduction
28.1.1 Principles of Optical Coherence Tomography (OCT)
28.1.2 OCT Systems (Table 28.1)
28.1.2.1 SD-OCT
28.1.2.2 SS-OCT
28.1.3 Scanning Protocols and Quantitative Measures: (Tables 28.2 and 28.3)
28.1.4 OCT Artifacts
28.1.5 Principles of OCTA
28.1.5.1 OCTA Algorithms (Table 28.4)
28.1.5.2 Scanning Protocols and Quantitative Measures: (Tables 28.5 and 28.6)
28.1.5.3 OCTA Artifacts
28.2 Applications of OCT and OCTA in Retinal Conditions
28.2.1 Diabetic Retinopathy
28.2.1.1 Non-proliferative Diabetic Retinopathy (NPDR)
28.2.1.2 Proliferative Diabetic Retinopathy (PDR)
28.2.1.3 Diabetic Maculopathy and Diabetic Macular Edema
28.2.2 Age-Related Macular Degeneration (AMD)
28.2.2.1 Early and Intermediate AMD
28.2.2.2 Neovascular AMD
28.2.2.3 Geographic Atrophy
28.2.2.4 The Choroid in AMD
28.3 Retinal Vascular Diseases
28.3.1 Retinal Arteriolar Occlusion or Ischemia
28.3.2 Retinal Vein Occlusion
28.3.3 Macular Telangiectasia Type 2 (Mac Tel Type 2)
28.4 Vitreomacular Interface Disorders
28.4.1 Epiretinal Membrane
28.4.2 Lamellar Macular Hole
28.4.3 Full-Thickness Macular Hole
28.5 Myopia-Related Retinal Diseases
28.5.1 Myopic Macular Degeneration
28.5.2 Myopic Choroidal Neovascularization
28.5.3 Myopic Traction Maculopathy
28.5.3.1 Technical Concerns
28.6 Uveitis
28.6.1 White Dot Syndromes
28.6.2 Sympathetic Ophthalmia and Vogt-Koyanagi-Harada Disease
28.6.3 Non-infectious Retinitis
28.6.4 Infectious Uveitis
28.6.4.1 Toxoplasmosis
28.6.4.2 Tuberculosis
28.7 Retinal and Choroidal Tumors
28.7.1 Choroidal Nevus
28.7.2 Choroidal Melanoma
28.7.3 Choroidal Hemangioma
28.7.4 Choroidal Osteoma
28.7.5 Hamartoma
28.7.5.1 Retinal Astrocytic Hamartoma
28.7.5.2 Combined Hamartoma of the Retina and Retinal Pigment Epithelium
28.8 Conclusion
References
29: Microperimetry
29.1 Introduction
29.2 Brief History of Microperimetry
29.3 Technology
29.3.1 Analysis of Retinal Sensitivity
29.3.2 Decibel Scale, Weberâs Law, Fechnerâs Law
29.4 Technique
29.4.1 Adaptation of the Retina and Pupil Dilation
29.4.2 Evaluation, Instruction, and Duration of Testing
29.4.3 Fixation Testing
29.4.4 Photopic, Scotopic, and Mesopic Conditions
29.4.5 Follow-Up
29.5 Clinical Application and Interpretation
29.5.1 Age-Related Macular Degeneration
29.5.1.1 Neovascular Age-Related Macular Degeneration
29.5.1.2 Non-Neovascular Age-Related Macular Degeneration and Geographic Atrophy
29.5.2 Diabetic Retinopathy and Diabetic Macular Edema
29.5.3 Stargardtâs Disease
29.5.4 Retinitis Pigmentosa
29.5.5 Other Clinical Applications of Microperimetry
29.6 Conclusion
References
30: Adaptive Optics
30.1 Introduction
30.2 Brief History of Adaptive Optics
30.3 Technology
30.3.1 Quantitative Measurement of Ocular Aberrations
30.4 Technique
30.4.1 Retinal Imaging
30.4.2 Types of AO Imaging Systems
30.4.2.1 Adaptive Optics and Flood-Illumination Ophthalmoscopy (AO-FIO)
30.4.2.2 Adaptive Optics and Scanning Laser Ophthalmoscopy (AO-SLO)
30.4.2.3 Adaptive Optics and Optical Coherence Tomography (AO-OCT)
30.4.2.4 Wavefront Sensorless Adaptive Optics (SAO)
30.5 Clinical Application and Interpretation
30.5.1 Healthy Eyes
30.5.2 Age-Related Macular Degeneration (AMD)
30.5.3 Diabetic Retinopathy
30.5.4 Glaucoma
30.5.5 Retinal Structures Imaged Using Adaptive Optics
30.6 Limitations
30.7 Future of Adaptive Optics and Conclusion
References
31: Electroretinography
31.1 Introduction
31.2 Electroretinogram (ERG)
31.2.1 Technology
31.2.1.1 Electroretinogram Types
31.2.1.2 Basic Equipment and Techniques
31.2.1.2.1 Stimulation
31.2.1.2.2 Recording
31.2.1.2.3 Active/Recording Electrodes
31.2.1.2.4 Reference Electrode
31.2.1.2.5 Ground Electrode
31.2.1.3 Other Technical Considerations
31.2.2 Waveform Origins and Characteristics in Full-Field ERG
31.2.2.1 Measurement of the ERG Concentrates on Peak Time and Amplitude
31.2.3 Clinical Considerations
31.2.3.1 Photoreceptor Disease
31.2.3.2 Inner Retinal Disease
31.2.4 Factors Affecting ERG [Table 31.3]
31.3 The Multifocal ERG
31.3.1 Technology
31.3.2 The Technique
31.3.2.1 Patient Preparation Tips
31.3.2.2 Recording Procedure
31.3.2.3 Response Analysis
31.3.2.4 Artefacts
31.3.2.5 Interpretation of Data
31.3.2.6 Clinical Applications of Multifocal ERG [Table 31.4]
31.4 The Pattern ERG
31.4.1 Clinical Applications
31.5 Other Tests
31.6 Conclusion
References
32: The Visual Evoked Potential
32.1 Introduction
32.2 Technology
32.2.1 Recording Equipment
32.2.1.1 Electrodes
32.2.1.2 Signal Acquisition
32.2.1.3 Display and Software Requirements
32.2.2 Stimuli
32.3 Technique
32.4 Clinical Application and Interpretation
32.4.1 Peak-Time
32.4.2 Amplitude
32.4.3 Shape
32.4.4 Transoccipital Asymmetry
32.5 Pitfalls and Pearls in Recording VEPs
32.6 Summary
References
33: The Clinical Electro-Oculogram
33.1 Introduction
33.2 History
33.3 Technology, Physics, and Mechanics of Electro-Oculogram
33.4 Technique
33.4.1 Clinical Applications
33.5 Clinical Interpretation
References
34: Computed Tomography: Dacryocystography
34.1 Introduction
34.2 Indications of Dacryocystography
34.3 Dyes Used in Dacryocystography
34.4 CT-DCG Scan Requisition
34.5 Methods
34.5.1 Patient Stories
34.6 Conclusion
References
35: Home Care and Teleophthalmology
35.1 Introduction
35.2 Visual Acuity
35.2.1 PEEK is one of the popular VA measurement devices. (Fig. 35.1)
35.3 Refraction
35.3.1 Folding Phoropter (FoFo) (Fig. 35.2)
35.3.2 QuickSee (e-See)
35.3.3 InstaRef
35.4 Intraocular Pressure
35.4.1 Rebound Tonometer
35.5 External Eye Examination
35.6 Visual Field
35.6.1 Order of Magnitude
35.7 Examination of the Anterior Segment
35.7.1 HOLDEN ⢠(Modular Slit Lamp with Applanation is a Handheld Slit Lamp)
35.7.2 Grabi ⢠is a Device to Image the Anterior Segment of the Eye
35.7.3 Pupil
35.7.3.1 Pupil-Lite (Device for Assessing the Pupil)
35.8 Fundus
35.8.1 Direct Ophthalmoscope
35.8.2 Indirect Ophthalmoscope
35.8.3 Integrating Teleophthalmology with Home Eye Care
35.9 Conclusion
References
Index