- •Preface
- •Contents
- •Acknowledgments
- •Abbreviations
- •Introduction
- •1: Diagnosis of Keratoconus
- •1.1 Clinical Findings
- •1.1.1 External Signs
- •1.1.2 Retinoscopy Signs
- •1.1.3 Slit Lamp Biomicroscopy Signs
- •1.2 Corneal Hysteresis
- •1.2.1 Principles
- •1.3 Confocal Microscopy
- •1.4 Specular Microscopy
- •1.5 Corneal Topography
- •1.5.1 Instruments Measuring Corneal Surface
- •1.5.1.1 Curvature-Based Instruments
- •1.5.1.2 Elevation Based Topographers
- •Bibliography
- •2.1 Morphological Patterns
- •2.2 Topographical Patterns
- •2.2.3.1 The Normal Cornea
- •2.2.4 Summary of Topographic Criteria of Keratoconus
- •2.4 Forme Fruste Keratoconus
- •2.5.1 Clinical Findings
- •2.5.2 Topographical Findings
- •2.5.3 Complications
- •2.5.4 Differential Diagnosis
- •Bibliography
- •3: Management of Keratoconus
- •3.1 Introduction
- •3.2 Management Modalities
- •3.2.1 Noninterventional Managements
- •3.2.1.1 Spectacle Correction
- •3.2.1.2 Contact Lenses
- •3.2.2 Interventional Procedures
- •3.2.2.1 Conductive Keratoplasty (CK)
- •3.2.2.2 Penetrating Keratoplasty
- •3.2.2.3 Lamellar Keratoplasty (DALK)
- •3.2.2.4 Intracorneal Rings (ICRs)
- •Mechanism of Actions
- •Conditions to Use ICRs
- •Guidelines
- •Factors for Poor Visual Outcome
- •Contraindications
- •Relative Contraindications
- •Considerations
- •Complications
- •Practical Notes in Using the Rings
- •3.2.2.5 Corneal Collagen Cross-Linking
- •Introduction
- •Indications
- •Conditions
- •Contraindications
- •Expected Changes After CxL
- •Typical Final Clinical Outcomes
- •Complications
- •3.2.2.6 Intraocular Refractive Lenses
- •Indications
- •Conditions
- •Contraindications
- •Considerations
- •Ophthalmic Examination
- •Basic Concepts
- •Complications
- •3.2.3 Combination Between Treatment Modalities
- •3.3 Management Parameters
- •3.3.1 Introduction
- •3.3.2 Management Parameters
- •3.3.2.3 Environment
- •3.3.2.4 Progression
- •3.3.2.5 Corneal Thickness
- •3.3.2.7 Refractive Errors and the Visual Acuity
- •3.3.2.8 Corneal Transparency and Stress Lines
- •Bibliography
- •4: Case Study
- •Introduction
- •Step 1: Analyzing Step
- •Step 2: Management Suggestion Step
- •Step 3: Discussion Step
- •4.1 Case 1
- •4.1.1 Step 1: Analyzing Step
- •4.1.2 Step 2: Management Suggestions
- •4.1.3 Step 3: Discussion
- •4.2 Case 2
- •4.2.1 Step 1: Analyzing Step
- •4.2.2 Step 2: Management Suggestions
- •4.2.3 Step 3: Discussion Step
- •4.3 Case 3
- •4.3.1 Step 1: Analyzing Step
- •4.3.2 Step 2: Management Suggestions
- •4.3.3 Step 3: Discussion Step
- •4.4 Case 4
- •4.4.1 Step 1: Analyzing Step
- •4.4.2 Step 2: Management Suggestions
- •4.4.3 Step 3: Discussion Step
- •4.5 Case 5
- •4.5.1 Step 1: Analyzing Step
- •4.5.2 Step 2: Management Suggestions
- •4.5.3 Step 3: Discussion Step
- •4.6 Case 6
- •4.6.1 Step 1: Analyzing Step
- •4.6.2 Step 2: Management Suggestions
- •4.6.3 Step 3: Discussion Step
- •4.7 Case 7
- •4.7.1 Step 1: Analyzing Step
- •4.7.2 Step 2: Management Suggestions
- •4.7.3 Step 3: Discussion Step
- •4.8 Case 8
- •4.8.1 Step 1: Analyzing Step
- •4.8.2 Step 2: Management Suggestions
- •4.8.3 Step 3: Discussion Step
- •4.9 Case 9
- •4.9.1 Step 1: Analyzing Step
- •4.9.2 Step 2: Management Suggestion
- •4.9.3 Step3: Discussion
- •Index
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4 Case Study |
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4.4.3Step 3: Discussion Step
This case is a mild posterior KC in a pregnant woman. Since pregnancy is thought to be a factor that triggers KC progression, it is crucial to monitor the cornea in close intervals (may be monthly) especially that ICRs and CXL are contraindicated during pregnancy due to social considerations. After delivery, if a decision is taken to do something for this case, it is CxL in order to stop the progression (if it happened) or to perform TG PRK since the refractive error and corneal thickness are within the
allowed limits. The most important thing here is that ICRs must not be used at all because it is a posterior KC. In posterior KC, the problem is in the posterior part of the cornea, which is out of field of action of the ICRs. CxL is a good choice because it strengthens the anterior corneal barrier against the posterior out-bulging.
It is not uncommon to see hyperopia in KC. If you look at the K-readings in the central 3 mm of the cornea, you can find that there are some low k-readings (39 dpt), which explains the hyperopic component of the patient’s refractive error (Table 4.4.1).