Refractive Surgery

✍ Scribed by Dimitri T. Azar MD

• Publisher: Elsevier
• Year: 2019
• Tongue: English
• Leaves: 523
• Edition: 3
• Category: Library

✦ Synopsis

Comprehensive and clinically focused, Refractive Surgery, 3rd Edition, brings you the knowledge and expertise of leading ophthalmology experts and refractive surgeons from around the world. Together they provide practical coverage of the latest advances in this fast-changing field, including improved optics and biomechanics, improved diagnostics, new surgical techniques, and more. Hundreds of high-quality photographs guide you from patient selection to mastery of surgical techniques.

• Offers step-by-step guidance on a wide range of common refractive procedures.
• Covers new topics such as management of LASIK complications; SMILE and management of SMILE complications; collagen cross-linking, including instrumentation and applications in keratoconus and ectasia; intracorneal lenses; and multifocal and accommodating IOLs.
• Contains a new chapter on Preoperative Evaluation of Keratoconus and Ectasia.
• Uses high-quality surgical video clips to demonstrate a variety of surgical techniques.
• Addresses initial as well as ongoing management of patients.
• Includes tables of indications, preferences, hot tips, and management of complications throughout, making guidance quick and easy to access.
• Enhanced eBook version included with purchase. Your enhanced eBook allows you to access all of the text, figures, and references from the book on a variety of devices.

✦ Table of Contents

Cover
Refractive Surgery
Copyright Page
Video Table of Contents
Foreword
Foreword to the First Edition
Preface
List of Contributors
Dedication
1 Terminology, Classification, and History of Refractive Surgery
Introduction: Why Do Patients Choose Refractive Surgery?
Emmetropia, Ametropias, and Presbyopia
Classification of Refractive Procedures
Keratorefractive Surgery
Keratorefractive Procedures: Myopia and Myopic Astigmatism
Laser Procedures
Laser Procedures for Myopia
Laser Procedures for Myopic Astigmatism
Incisional Procedures: A Historical Perspective
Incisional Procedures for Myopia
Incisional Procedures for Myopic Astigmatism
Nonlaser Lamellar Procedures for Myopia: A Historical Perspective
Corneal Implants for Myopia
Hyperopia and Hyperopic and Mixed Astigmatism
Laser Procedures
Laser Procedures for Hyperopia
Laser Procedures for Hyperopic and Mixed Astigmatism
Incisional Procedures for Hyperopia
Nonlaser Lamellar Procedures for Hyperopia
Thermal Procedures for Hyperopia
Aphakia
Presbyopia
Monovision
Conductive Keratoplasty
Multifocal Corneal Ablation and PresbyLASIK
Corneal Inlays
Hybrid
Lenticular and Scleral Refractive Surgical Procedures
Clear Lens Extraction
Phakic Intraocular Lenses
Bioptics
Aphakia
Presbyopia
Multifocal Intraocular Lenses
Accommodating and Pseudo-Accommodating Lenses
Phaco-Ersatz
Scleral Relaxation and Scleral
Summary
References
2 Corneal Wound Healing Following Keratorefractive Surgery
Introduction
Radial Keratotomy
Cellular Mechanism of Refractive Regression After Radial Keratotomy and Role of Corneal Myofibroblast
Excimer Laser Refractive Surgery
Wound-Healing Response Following Excimer Laser Photorefractive Keratectomy
Epithelium
Keratocyte Apoptosis
Stromal Repair
Myofibroblasts, Regression, and Haze After Photorefractive Keratectomy
Wound Healing After LASIK
Epithelium
Keratocyte Apoptosis
Stromal Wound Healing
References
3 Physiologic Optics for Refractive Surgery
Introduction
Geometric Optics
Prisms and Lenses
Images and Vergence
Magnification
Refractive Errors of the Human Eye
Emmetropia
Myopia
Hyperopia
Astigmatism
Correction of Refractive Errors and Visual Distortions
Oblique Astigmatism
Image Magnification
Lens Effectivity
Preoperative Optical Considerations for Refractive Surgery
Contact Lens Wear
Vertex Distance
Anisometropia and Aniseikonia
Cycloplegic Refraction
Hyperopia
Diabetes
Pupil Size
Extraocular Motility Examination
Accommodation
Spectacle Overcorrection of Myopia
Intraoperative Optical Considerations of Refractive Surgery
Optical Axis, Nodal Points, and Visual Axis
Pupil, Optical Zones, and the Chief Ray
Line of Sight and Pupillary Axis
Angles Kappa and Lambda
Pupil Eccentricity
Foveal Eccentricity
Summary of the Role of the Visual Axis and the Optical Zone
Pupillary Dilation
Recommended Technique for Optimal Centration in Corneal Refractive Surgical Procedures
Optical Considerations After Refractive Surgery
Pupil Size
Oval Topographic Zones After Astigmatic Surgery
Topographic Maps
Astigmatic Dial
Prescribing Spectacles After Refractive Surgery
Spasm of Accommodation
Convergence Insufficiency
Presbyopia
Prescribing for Presbyopia After Refractive Surgery
Fluctuating Vision
Unequal Amplitude of Accommodation
Bifocal Type
References
4 Corneal Topography
Introduction
Curvature
Elevation Topography
Interpretation of Posterior Surface Elevation Topography
Functional Corneal Representations Derived From Shape
Refractive Power Maps
Functional Optical Zone
Anterior Corneal Wavefront Aberrations
Topographic and Tomographic Technologies
Conclusions
References
5 Wavefront Analysis
Introduction
History of Wavefront: The Debate Concerning the Phenomenon of Light
Wavefront Theory
What Is a Wavefront?
How Does a Wavefront Propagate?
What Is Diffraction?
Diffraction and Fourier Transform
Ocular Aberrations
Wavefront Measurement
Outgoing Reflective Aberrometry Using Hartmann–Shack Wavefront Analyzers
Wavefront Study With Retinal Imagery
Tscherning Analyzing System
Retinal Ray Tracing
Ingoing Adjustable Refractometry
Double-Pass Aberrometry (Slit Skiascopy/OPD Scan Device)
Accuracy and Repeatability of Wavefront Measurements
Wavefront Analysis and Map Interpretation
Principles of Wavefront Reconstruction
Use of Zernike Polynomials in Wavefront Sensing
Principles of the Wavefront Decomposition Into Zernike Polynomials
Wavefront Interpretation Based on Zernike Polynomial Decomposition
Application to the Wavefront Interpretation
Statistical Variation of Aberration in Healthy Eyes
Variation of Aberration After Refractive Surgery
Variations of Aberration With Aging
Measures of Optical Performance of the Eye
Pupil Plane Metrics: Wavefront Map Metrics
Vergence Maps
Image Plane Metrics
Point-Spread Function
Optical Transfer Function, Modulation Transfer Function, Phase Transfer Function
Relations Between Point Spread Function and Optical Transfer Function
Metrics and Polychromatic Light
Prediction of Subjective Refraction From Wavefront Aberration Maps Vision Quality Metrics
Conclusion
References
6 Optical Coherence Tomography in Refractive Surgery
Introduction
Instruments
Scanning Protocols and Measurements
Applications in Refractive Surgery
Preoperative Evaluation
Postoperative Evaluation
OCT Angiography
Further Reading
7 Excimer Lasers
Introduction
Lasers: General Physical Principles
Principles of Laser Emission
Laser–Cornea Interactions
Properties of the Excimer Laser
Laser Beam Generation
Gaseous Medium
Beam Homogenization
Beam Delivery System
Full-Beam Systems (Fig. 7.2)
Scanning Slit Delivery
Flying Spot
Computer
Work Area
Parameters of the Laser Beam
Pulse Duration
Pulse Frequency
Pulse Energy
Fluence
Rate of Ablation
Effects of the Excimer Laser on Corneal Tissue
Molecular Effects
Mutagenicity
Tissular Effects
Eye Tracker
Eye Movements During Refractive Corneal Photoablation
Eye Tracker Function
Eye Movement Recording
FDA-Approved Excimer Lasers (2006 to Present)
Topography and Wavefront-Based Treatments in Excimer Lasers
Topography-Guided Laser Refractive Surgery
Wavefront-Based Laser Refractive Surgery
Topography-Guided Ablation Profiles Compared to Wavefront-Based Treatments
Conclusions
References
8 Laser and Mechanical Microkeratomes
Introduction
Mechanical Microkeratomes
Laser Microkeratomes: The Femtosecond Lasers
Physical Principles of the Femtosecond Laser
Corneal Interactions With the Femtosecond Laser
Corneal Flap Preparation With the Femtosecond Laser
Advantages and Disadvantages of the Femtosecond Laser
Comparison Between Mechanical Microkeratome and Femtosecond Laser
Conclusions
References
9 Crosslinking Instrumentation
Introduction
Crosslinking Equipment: Common Architecture and Internal Parts
UV-Light Source
Wavelength Selection
Temperature Influence on Wavelength
Temperature Influence on Power Output
The UV Light Optical Beam Delivery System
Optical Output Power Density Distribution
Optical Beam Aiming and Positioning, Auxiliary Aiming Beam
Optical Beam Spot Size
The Main Electronic Control System
Main Processor, Display, and Keyboard
Watchdog Circuit
The Power Control Block, Current Sensor, Main Photodiode Led Control Loop
Continuous and Pulsed Power Control
Auxiliary Devices
Interlock Device
Sound Emission
Aiming Beam, or Alignment Auxiliary System Control
Eye Tracker
Regulatory and Normative Requirements
A Survey of Crosslinking Platforms on the Market
Nonphotoactivated Crosslinking Agents
References
10 Ocular Diseases of Importance to the Refractive Surgeon
Introduction
Blepharitis and Meibomitis
Anterior Blepharitis
Meibomitis and Meibomian Gland Dysfunction
Bacterial Conjunctivitis and Keratitis
Chronic Bacterial Conjunctivitis and Keratitis
Viral Conjunctivitis and Keratitis
Tear Abnormalities and Exposure Keratitis
Tear Film Abnormalities
Neurotrophic Keratitis
Exposure Keratopathy
Immunologic Diseases of the Conjunctiva and Cornea
Ocular Allergic Diseases
Allergic Conjunctivitis
Atopic Keratoconjunctivitis
Giant Papillary Conjunctivitis
Ocular Mucous Membrane Pemphigoid
Connective Tissue Disease and Systemic Vasculitides
Developmental Abnormalities of the Cornea
Megalocornea
Microcornea
Oval Cornea
Sclerocornea
Posterior Keratoconus
Keratoglobus
Keratoconus
Other Noninflammatory Corneal Thinning Disorders
Epithelial Corneal Dystrophies
Map-Dot Fingerprint Dystrophy
Meesmann Dystrophy
Reis–Bückler Dystrophy
Band Keratopathy
Glaucoma
Ocular Hypertension and Primary Open-Angle Glaucoma
Pigment Dispersion Syndrome and Pigmentary Glaucoma
Steroid-Induced Glaucoma
Congenital Glaucoma
Chorioretinal Disorders
Myopic Macular Degeneration
Lattice Degeneration of the Retina
Retinal Detachment
Other Peripheral Retinal Degenerations
White Without Pressure
Cobblestone Degeneration
Peripheral Pigmentary Degeneration
Idiopathic Multifocal Choroiditis
Choroidal Hemorrhages/Effusions
Choroidal Folds
Acquired Retinoschisis
Nanophthalmos and Uveal Effusions
Inherited Retinal Degenerations
Optic Nerve Disorders
Optic Disc Drusen
Nonarteritic Anterior Ischemic Optic Neuropathy
Systemic Associations
Diabetes Mellitus
Transient Refractive Shifts
Myopic Shifts
Hyperopic Shifts
Permanent Myopia
Myopia and Diabetic Retinopathy
Acquired Immunodeficiency Syndrome
Albinism
Wagner and Stickler Syndromes
Marfan Syndrome
Weill–Marchesani Syndrome
Down Syndrome
Gyrate Atrophy
Cerebral Palsy
References
11 Patient Evaluation for Refractive Surgery
Introduction
Philosophical Issues
Guidelines for Patient Selection
Absolute Contraindications
Ocular Hypertension and Glaucoma
Connective Tissue Disease
Corneal Dystrophies
Patient Expectations
Relative Contraindications
Dry Eye
Diabetes Mellitus
Human Immunodeficiency Virus
Previous Ocular Surgery
After Retinal Detachment Surgery
After Cataract Surgery
After Penetrating Keratoplasty
Guidelines for Preoperative Examination
Assessment of Contraindications and Appropriateness for Surgery
Assessment of Patient Needs and Expectations
Review of Risks and Benefits
Reading Materials
Questionnaire
Time Interval Between Eyes
Preoperative Examination
Discontinuance of Contact Lens Wear
Refraction
Keratometry
Computer-Assisted Videokeratography
Wavefront Aberrometry Measurement
Contrast Sensitivity and Glare Testing
Pupillary Size
Ocular Dominance
Ocular Motility Issues
Pachymetry and Specular Microscopy
Informed Consent
References
12 Preoperative Evaluation of Keratoconus and Ectasia
Introduction
Guidelines for Preoperative Examination
Corneal Cross-Linking
Definition of Progression
Corneal Cross-Linking Techniques Guideline
Clinical Evaluation
Topography Evaluation
Prognostic Factors
Intracorneal Ring Segments
Prognostic Factors
Refractive Evaluation
Corneal Tomography/Topography Evaluation
ICRS Indications
Surgical Plan and Patient Preparation
Nomogram
Penetrating Keratoplasty and Deep Anterior Lamellar Keratoplasty
Introduction
Deep Anterior Lamellar Keratoplasty
Donor Characteristics for Keratoplasty
Phakic Intraocular Lens for Corneal Ectasia
Location of Phakic Intraocular Lenses
Lens Size
Posterior Chamber Phakic Intraocular Lenses Vault
Anterior Chamber Phakic Intraocular Lenses Vault
Indications for Phakic Intraocular Lens
Implantation Criteria
Indications
Relative Indications
Contraindications
Anterior Segment Optical Coherence Tomography
References
13 LASIK, Q-Based, and Wavefront-Guided LASIK for Myopia, Hyperopia, and Astigmatism
Introduction
Pure Myopia (Video 13.1)
LASIK for Low to Moderate Myopia
LASIK in High Myopia
Reducing the Magnitude of the Treatment (Intended Undercorrection)
Reducing the Programmed Optical Zone
Use of Multizone/Multipass or Aspheric Profiles of Ablation
Reducing the Thickness of the Corneal Flap
Pure Hyperopia (Video 13.1)
Outcomes of Hyperopic LASIK
Simple, Compound, and Mixed Astigmatic Errors (Video 13.1)
Simple Astigmatism
Simple Hyperopic Astigmatism
Simple Myopic Astigmatism
Relation Between Negative and Positive Cylindrical Ablations
Compound Myopic, Hyperopic, and Mixed Astigmatism
Hyperopic and Mixed Astigmatism
Compound Myopic Astigmatism
Sequential Strategy
Elliptical Strategy
Strategy to Optimize the Clinical Outcomes of Astigmatic Treatments
Topography-Guided Ablations
Rationale for Topography-Guided Ablations With LASIK
Q-Based and Wavefront-Guided Ablations
Rationale for Q-Based and Wavefront-Guided Ablation With LASIK
Q-Based Ablations
Wavefront-Guided Ablations
Characteristics of Custom-Q Profile of Ablation
Characteristics of Wavefront-Guided Profile of Ablation
Prerequisites for Successful Q-Based and Wavefront-Guided Ablations
Q-Based Ablations
Wavefront-Guided Ablations
Quality of Wavefront Reconstruction
Quality of Ablation Profile Calculation
Quality of Ablation Profile Delivery
Quality in Minimizing Excessive Unexpected Corneal Response in Custom Q and Wavefront-Guided Corrections
Results of Q-Based and Wavefront-Guided Lasik Procedures
References
14 LASIK and TopoLink for Irregular Astigmatism
Introduction
The Technique of TopoLink
Examples of Topolink (Videos 1 to 3)
Patient 1: Irregular Astigmatism After Penetrating Keratoplasty and Astigmatic Keratotomy
Patient 2: Irregular Astigmatism
Patient 3: Decentered Ablation
Results of TopoLink in Repair Procedures
References
15 LASIK Complications and Their Management
Introduction
Intraoperative Complications
Inadequate Exposure
Suction Loss (Videos 4 to 6)
Corneal Epithelial Defect
Incomplete or Irregular Cut (Video 7)
Decentered Flaps
Free Cap (Video 1)
Buttonhole (Videos 8 and 9)
Pizza Slicing
Limbal Hemorrhage
Intraoperative Complications Specific to Femtosecond Laser LASIK
Vertical Gas Breakthrough
Anterior Chamber Bubbles (Video 3)
Opaque Bubble Layer
Early or Hard Opaque Bubble Layer
Late or Soft Opaque Bubble Layer
General Photoablation-Related Complications
Decentration
Overcorrection and Undercorrection
Early Postoperative Complications
Interface Debris
Flap Displacement and Flap Folds (Video 2)
Flap Striae and Folds (Video 13)
Loss of the Flap/Cap
Diffuse Lamellar Keratitis
Pressure-Induced Stromal Keratopathy
Infectious Keratitis
Epithelial Ingrowth (Videos 10 to 12)
Central Toxic Keratopathy
Late Postoperative Complications
Induced or Iatrogenic Keratectasia
Night Vision Problems and Glare
Transient Light Sensitivity Syndrome
Rainbow Glare
LASIK-Associated Dry Eye and Neurotrophic Epitheliopathy
References
16 Small-Incision Lenticule Extraction (SMILE)
Introduction
Principles Behind SMILE
Surgical Techniques for SMILE (Video 16.1)
Preoperative Considerations
Patient Selection
Centration
Incision Technique
Appropriate Laser Pulse
Shape of the Incision
Centering Accuracy of the Incision
Other Important Considerations
Thickness of Lenticule Cap
Corneal Wound Healing After SMILE
Corneal Biomechanics
Literature Review
Inclusion Criteria
Results
Predictability, Safety, and Efficacy
Intraoperative Complications
Postoperative Complications
Explanation of the Graphs (Dry Eye)
Corneal Biomechanics
Further Areas of SMILE Applicability
References
17 Small-Incision Lenticule Extraction (SMILE) Complications and Their Management
Introduction
Theoretical Advantages and Limitations of SMILE
Advantages
Limitations
How to Avoid Complications
Difficulties in Obtaining Suction
Preparation for Lenticule Extraction
Lenticule Dissection and Extraction
Flushing the Interface
Management of Intraoperative Complications
Decentration
Suction Loss
Difficult Dissection of the Lenticule
Black Spots
Lenticule Tears and Retained Lenticular Fragments
Cap Tear
Epithelial Abrasions
Management of Postoperative Complications
Diffuse Lamellar Keratitis
Infection
Epithelium and Other Foreign Bodies in the Interface
Interface Fluid Collection
Ectasia
Dry-Eye Syndrome
Undercorrection and Overcorrection and Retreatment Options
References
18 Photorefractive Keratectomy
Introduction
Excimer Laser Physics and Beam Tissue Interaction
Postoperative Care
PRK Complications to Consider
References
19 LASEK and Epi-LASIK
Introduction
Definition and Terminology
Theoretical Advantages of LASEK
Alcohol-Assisted Epithelial Removal
Effect of Alcohol on Epithelial Cell Survival In Vitro
Transmission Electron Microscopy of Corneal Epithelium Specimen
Use of Mitomycin C to Avoid Haze
Surgical Techniques
Azar Flap Technique
Camellin Technique
Vinciguerra Butterfly Technique
Alternatives to Alcohol-Assisted Epithelial Removal
Epi-LASIK
Introduction
The Original Surgical Procedure
Postoperative Care
Epi-LASIK Clinical Results
Gel-Assisted Epithelial Removal (McDonald Technique)
Trans-epithelial Photorefractive Keratectomy
Epi-Bowman Keratectomy
Clinical Outcomes of LASEK
Retreatments
Complications
LASEK vs Photorefractive Keratectomy and Epi-LASIK
LASEK vs LASIK
Summary of Clinical Reports
Summary and Future Applications/Corneal Cross-Linking
References
20 Phototherapeutic Keratectomy (PTK) and Intralamellar PTK
Introduction
Excimer Laser Advantages and Safety
Phototherapeutic Keratectomy and Intralamellar PTK Indications
Surgical Planning and Technique
Preoperative Evaluation
Preoperative Preparation
Laser Treatment and General Surgical Techniques
IL-PTK: Surgical Technique (Fig. 20.5)
Elevated Central Corneal Nodules (Video 20.4)
Multiple Surface Irregularities
Corneal Dystrophies (Videos 20.1 and 20.6)
Recurrent Corneal Erosions (Videos 20.2 and 20.3)
Corneal Scars
Infectious Keratitis
Refractive Surgery Complications
Prismatic Photokeratectomy
Postoperative Management
Corneal Wound Healing
Complications From PTK and Intralamellar PTK
Refractive Complications
Early Postoperative Complications
Late Postoperative Complications
Outcomes of PTK: Major Studies and Specific Diseases
Corneal Dystrophies
Recurrent Corneal Erosions
Corneal Scars (Video 20.5)
Refractive Surgery
Visual Acuity Outcomes in Lamellar Keratoplasty
Excimer Laser and Lamellar Keratoplasties
References
21 Principles of Corneal Cross-Linking
Introduction
Basic Principles
Cross-Linking for Keratoconus
Cross-Linking Beyond Keratoconus
References
22 Epithelium Off and Transepithelial Cross-Linking
Introduction
Basic Principles of Corneal Cross-Linking
Basic Research Results
Standard Cross-Linking Procedure: Epi-Off Cross-Linking (Video 22.1)
Rapid Accelerated Technique
Transepithelial Cross-Linking
Cross-Linking Results
Alternative Uses of Corneal Cross-Linking
Infections
Pseudophakic Bullous Keratopathy
References
23 Orthokeratology
Introduction
Changes in Refraction and Visual Acuity
Topographic Corneal Curvature Changes
Anterior Segment Changes
Orthokeratology for Myopia Control
Other Corneal Changes
Corneal Pigmented Arc
Fibrillary Lines
Corneal Staining
Lens Binding
Microbial Keratitis in Orthokeratology
Patient Acceptance
References
24 Radial and Astigmatic Keratotomy
Introduction
Success and Failure of Radial Keratotomy
Astigmatic Keratotomy
Limbal Relaxing Incisions
Mechanism of Action
Patient Selection
Astigmatic Power
Steeper Corneal Meridian
Front-Cutting Blade
Mechanized Arcuate Keratomes and Femtosecond Lasers
Surgical Technique
AK-LASIK
Complications
Infection
Perforation
Undercorrection
Overcorrection
Rotation of Axis With Residual Astigmatism
Irregular Astigmatism
Recurrent Erosions and Superficial Punctate Keratitis
References
25 Conductive Keratoplasty and Laser Thermokeratoplasty
Introduction
Historical Background
Response of Corneal Collagen to High Temperature
Laser Thermokeratoplasty
Holmium:YAG Lasers
Contact Holmium:YAG
Noncontact Holmium:YAG
Clinical Outcomes of LTK
Conductive Keratoplasty
Conductive Keratoplasty Procedure (Video 25.1)
Visual Outcomes
Visual Acuity
Safety
Stability
Patient Satisfaction
References
26 The Intrastromal Corneal Ring Segments
Introduction
Results of Clinical Trials With the Intrastromal Corneal Ring
Nonfunctional Eye Study
Sighted Eye Studies
Removal and Exchanges (Video 26.5)
Prognosis Factors
Surgical Technique (Videos 26.1 to 26.3)
Therapeutic Applications (Video 26.4)
References
27 Intraocular Lens Calculations After Keratorefractive Surgery
Introduction
Source of Error in K-Reading Following Corneal Refractive Surgery
Present Methods for K-Reading After Corneal Refractive Surgery
Clinical History Method
Example
Hard Contact Lens Method
Example
Calculation of the Corneal Dioptric Power by Measuring the Anterior Corneal Curvature
Example
Direct Measurement of the Total Corneal Power Using Modified Effective Index of Refraction
Example
Posterior Corneal Curvature Method
Discussion
References
28 Phakic Intraocular Lens Power Calculations
Introduction
Van der Heijde’s Equation and Holladay’s Equation
Azar/Wong Simplified Phakic IOL Formula
Effective Lens Position
Anterior Chamber Depth
Keratometry and Refractive Index
White-to-White Distance
Mathematical Analysis of the Predictability of Different Types of PIOL
Preoperative Refraction
Vertex Distance
Effective Lens Position and Anterior Chamber Depth
Keratometry and Refractive Index
Bioptics and Piggyback IOL
Bioptics
Piggyback IOL
IOL Calculations After PIOL Implantation
Summary
References
29 Refractive Lens Exchange
Introduction
Pearls in Surgical Technique
IOL Power Calculation
Main Indications and Outcome
Conclusions
References
30 Iris-Fixated Phakic Intraocular Lenses
Introduction
Lens Designs
Indications and Contraindications
Surgical Procedure
Preparation
IOL Power Calculation
Preoperative Miosis
Operative Technique (Videos 30.1 and 30.3)
Incision Techniques
Incision Size
Paracenteses
Viscoelastic Material
Introduction of the Phakic IOL Into the Anterior Chamber
Guaranteeing Pupillary Miosis
Centration and Fixation of the IOL
Iridectomy/Iridotomy
Wound Closure
Particularities of the Toric and Foldable Models
The Toric Lens
The Artiflex Lens (Video 30.2)
Removal of the Viscoelastic Material
Postoperative Management
Outcome and Complications
Functional Outcome
Results for Myopia
Results for Hyperopia
Results for Astigmatism
Optical Quality After Artisan Implantation
Complications
Anterior Chamber Inflammation
Glaucoma
Impact on the Crystalline Lens
Endothelium Tolerance
Iris Changes
Miscellaneous
Conclusions
References
31 Posterior Chamber Phakic Intraocular Lens
Introduction
Lens Design
Preoperative Evaluation
Surgical Technique (Video 31.1)
Preparation and Anesthesia
Surgical Procedure
Inserting the Implant With an Injector (Fig. 31.1)
Inserting the Implant With Forceps (Fig. 31.2)
Functional Results
Predictability
Visual Acuity
Stability
Quality of Vision
Halos
Anatomic Outcome
Early Postoperative Complications
Decentration of the Implant
Early Postoperative Intraocular Pressure Rise
Long-Term Postoperative Outcome
Endothelial Cell Damage
Subclinical Inflammation
Pigmentary Dispersion
Elevated Intraocular Pressure
Cataractogenesis
Advantages and Disadvantages
References
32 Complications of Phakic Intraocular Lenses
Introduction
Anterior Chamber IOLs
Historic Angle-Supported Models
Baikoff‘s Lens Models
ZSAL Models
Phakic 6 IOL
Foldable Lenses
Duet Kelman Lens
Acrysof Phakic Implant (Cachet, Alcon)
GBR Vivarte Lens
Current Anterior Chamber IOLs: Iris-Fixated Models
Posterior Chamber IOLs
Sulcus-Supported Models
Zonular-Supported Models
Conclusions
References
33 Phakic Intraocular Lens Explantation (PIOL)
Introduction
Cataract Formation
Endothelial Cell Loss
Decentration/Dislocation of PIOL
Pupillary Ovalization
Pupillary Block Glaucoma
Pigment Dispersion
Retinal Detachment
Endophthalmitis
Preoperative Assessment
Phakic Intraocular Lens Exchange
Simple PIOL Removal
Bilensectomy
IOL Calculation in Bilensectomy
Surgical Technique (Videos 33.1 to 33.3)
Angle-Supported PIOL
Iris-Fixated PIOL
Posterior Chamber PIOL
Bilensectomy Results
References
34 Physiology of Accommodation and Presbyopia
Introduction
Accommodation
Historical Background
Current Understanding of Accommodation
Presbyopia
Lenticular Causes of Presbyopia
Extralenticular Causes of Presbyopia
Limitations to the Understanding of Accommodation and Presbyopia
Conclusion
References
35 Monovision
Introduction
Achieving Monovision
Ideal Monovision Result
Visual Performance in Monovision
Binocular Visual Acuity
Interocular Blur Suppression
Stereoacuity
Contrast Sensitivity
Peripheral Vision and Visual Fields
Binocular Depth of Focus
Phorias
Task Performance
Factors Influencing Monovision Success
Preoperative Patient Evaluation
Monovision Trial
Determining the Eye for Distance
Determining the Degree of Add
Crossed Monovision
References
36 Scleral Surgery for Presbyopia
Introduction
Scleral Expansion Segments— Manual Approach
Scleral Expansion Segments—Automated Approach: VisAbility Micro-Insert
Complications of Manual Surgery
Clinical Outcomes of Manual Surgery
Clinical Outcomes of Automated Approach
Other Scleral Expansion Procedures
Anterior Ciliary Sclerotomy
Laser Scleral Expansion
LaserACE Approach
Scleral Expansion and Glaucoma
References
37 Multifocal Corneal Surgery for Presbyopia
Introduction
Theoretical Considerations
Depth of Focus and Optical Aberrations
What Is Multifocality?
Multifocality Versus Monovision
Pseudoaccommodation: The Importance of Corneal Multifocality and Optical Aberrations
Asphericity Modulation
Practical Consequences
General Considerations
Corneal Multifocal Profile of Ablation
Early Techniques
Spherical Aberration and Multifocality in Practice
Changing the Ocular Spherical Aberration With Laser Corneal Ablation
Current Proposed Methods
Peripheral Near Addition Zone
Central and Paracentral Near Addition
Clinical Recommendations for Successful Multifocal Cornea
Limitations of Current Treatments and Future Orientations
References
38 Corneal Implants and Inlays
Introduction
Principles of Corneal Inlays
FDA-Approved Corneal Inlays in Use
KAMRA Inlay (Video 38.1)
Indications and Contraindications for KAMRA Inlay Implantation
KAMRA Inlay Safety and Efficacy
Postoperative Complications for KAMRA Inlay
Raindrop Inlay
Indications and Contraindications for Raindrop Inlay Implantation
Raindrop Inlay Safety and Efficacy
Postoperative Complications for Raindrop Inlay
Presbia Flexivue Microlens Inlay
Flexivue Microlens Inlay Safety and Efficacy
References
39 Multifocal Intraocular Lenses
Introduction
Optics of Multifocality (Videos 39.1 and 39.2)
In vitro Optical Quality
Visual Acuity
Depth of Field
Contrast Sensitivity
Photic Phenomena (Glare and Halos)
Spectacle Use
Posterior Capsular Opacification
Patient Satisfaction and Quality of Life
Final Considerations
References
40 Refractive Surgical Procedures to Restore Accommodation
Introduction
Accommodation: The Helmholtz Theory
Presbyopia: The Loss of Accommodation With Age
Presbyopia Correction: an Overview
Traditional Techniques
Pseudo-Accommodating IOLs
Restoration of Accommodation
Lens Refilling
The Development of Lens Refilling
The Challenges of Lens Refilling
Surgical Technique
Material
Optics
Secondary Cataract
The Status of Lens Refilling: Where Are We Today?
The Accommodation Club
References
41 Smart Intraocular Lenses, Accommodating and Pseudoaccommodating Intraocular Lenses for Presbyopia
Introduction
Smart Intraocular Lenses
Single-Optic, Flexible Haptic Support
Crystalens Surgical Technique
Other Single-Optic Systems
Dual-Optic System, Telescoping Intraocular Lens
Dynamic Optic (Lens Refilling)
Magnetic Lens System
Other Concepts
Light Adjustable Lens
Accommodating Optical Shift Concepts
Conclusion
References
42 Postkeratoplasty Astigmatism
Introduction
Pathogenesis of Postkeratoplasty Astigmatism
Preoperative Factors
Operative Factors
Suturing Technique
Management of Significant Postkeratoplasty Astigmatism
Management of Astigmatism While Sutures Are In: Suture Manipulation
Selective Suture Removal
Suture Adjustment
Management of Astigmatism After Suture Removal
Relaxing Incisions (Video 42.2)
Operative Technique
Femtosecond Laser-Assisted Arcuate Keratotomy (Video 42.1)
Wedge Resections
Operative Technique
Femtosecond Laser-Assisted Wedge Resection (Video 42.3)
Excimer Laser
Toric Intraocular Lenses
References