Slatter's Fundamentals of Veterinary Ophthalmology (eBook)

Front cover 1
PageBurst 2
Slatter's Fundamentals of Veterinary Ophthalmology 5
Copyright page 8
Contributors 9
Dedication 10
Preface and Acknowledgments 11
Table of Contents 12
1 Basic Structure and Function of the Eye 15
Fundamentals of Vision 15
Luminance 15
Motion 17
Depth Perception 18
Texture (Visual Acuity) 19
Optical Factors in Visual Acuity 20
Retinal Factors in Visual Acuity 21
Estimates of Visual Acuity 23
Color Vision 24
Central Visual Pathways 26
2 Development and Congenital Abnormalities* 27
Development 27
Embryogenesis and Organogenesis 27
Differentiation 30
Retina 30
Optic Nerve 31
Vitreous 31
Lens 33
Primitive Vascular System 34
Ciliary Body and Iris 36
Iridocorneal Angle 36
Cornea and Anterior Chamber 36
Choroid, Sclera and Extraocular Muscles 36
Eyelids and Third Eyelid 37
Nasolacrimal System 38
Congenital Abnormalities 38
Anophthalmos and Microphthalmos 38
Cyclopia and Synophthalmia 39
Coloboma 39
3 Ocular Pharmacology and Therapeutics 41
General Principles of Ocular Pharmacology 41
Routes of Administration 41
Continuous or Intermittent Ocular Surface Lavage Systems 42
Topical Formulations 42
Solutions and Suspensions (Eye Drops) 44
Ointments 44
Subconjunctival, Subtenons, and Retrobulbar Injections 45
Systemic Drug Administration 46
Antibacterial Drugs 47
Selection and Administration of Antibiotics 47
Penicillins 48
Penicillin G 48
Sodium Methicillin 48
Sodium Oxacillin 48
Amoxicillin and Ampicillin 48
Cephalosporins 48
Chloramphenicol 50
Aminoglycosides 51
Neomycin 51
Gentamicin 51
Tobramycin 51
Amikacin 51
Cyclic Polypeptides 51
Bacitracin 51
Polymyxin B 51
Tetracyclines 51
Azithromycin 52
Sulfonamides 52
Fluoroquinolones 52
Enrofloxacin, Orbifloxacin, and Pradofloxacin 52
Ciprofloxacin, Ofloxacin, and Others 53
Antifungal Drugs 53
Natamycin 53
Azoles 53
Flucytosine 53
Amphotericin B 54
Antiviral Drugs 55
Idoxuridine 55
Trifluridine (Trifluorothymidine) 55
Vidarabine 55
Acyclovir and Valacyclovir 55
Cidofovir 55
Ganciclovir 56
Penciclovir and Famciclovir 56
Lysine 56
Corticosteroids 56
Properties of Corticosteroids 56
Ocular Penetration of Corticosteroids 57
Long-Term Therapy 58
General Indications for Corticosteroid Use 58
Nonsteroidal Antiinflammatory Drugs 58
Immunomodulating Therapy (Immunosuppressants and Immunostimulants) 59
Azathioprine 59
Cyclosporine 60
Tacrolimus and Pimecrolimus 60
Immunostimulants 60
Mast Cell Stabilizers and Antihistamines 60
Hyperosmotic Agents 61
Mannitol 61
Topical Hyperosmotic Sodium Chloride 61
Autonomic Drugs 61
Parasympatholytic (Anticholinergic) Agents 61
Atropine 61
Tropicamide 62
Miscellaneous Parasympatholytic Agents 63
Sympathomimetic (Adrenergic) Agents 64
Epinephrine (Adrenaline), Dipivefrin, and Phenylephrine 64
Parasympathomimetic (Cholinergic) Agents 64
Direct-Acting Parasympathomimetic Agents 64
Pilocarpine. 64
Indirect-Acting Parasympathomimetic Agents 65
Demecarium. 65
Carbachol. 65
Sympatholytic Agents (Adrenergic Antagonists) 65
Topical and Systemic Carbonic Anhydrase Inhibitors 65
Prostaglandin Analogues 66
Local Anesthetics 66
Ocular Analgesia 67
Topically Applied Agents 67
Opioids 67
Atropine 67
NSAIDs 67
Systemically Administered NSAIDs and Analgesic Agents 67
Retrobulbar Anesthesia 68
Enzymes and Enzyme Inhibitors 68
Hyaluronidase 68
Tissue Plasminogen Activator 68
Protease Inhibitors 68
Tear Replacement Preparations (Artificial Tears) 68
Miscellaneous Therapeutic Agents 69
Surgical Adhesives 69
Eye Washes (Collyria) 69
Germicides 69
Astringents and Cauterants 69
Vitamins 69
Medical Cataract Treatments 69
Antiparasitic Agents 71
Physical Therapy 71
Contact Lenses 71
Irradiation 71
ß-Irradiation 72
.- and X-Irradiation 72
Hyperthermia 72
Cryosurgery 72
Lasers in Veterinary Ophthalmology 73
4 General Pathology of the Eye 74
Ocular Injury 74
Causes of Ocular Injury 74
Consequences of Ocular Injury 74
Agenesis, Aplasia, Hypoplasia 74
Hypertrophy 75
Hyperplasia 75
Atrophy 75
Metaplasia 75
Dysplasia 76
Dystrophy 76
Necrosis 76
Loss of Barrier Function. 77
Loss of Electrical Activity. 78
Loss of Secretory Function. 78
Initiation of Inflammation: the First Step Toward Normalization. 78
Ocular Inflammation 78
Peculiarities of Ocular Inflammation 79
Corneal Inflammation 80
Uveitis 81
Common Sequelae of Intraocular Inflammation 81
Inflammatory Retinal Detachment 81
Cataract 82
Glaucoma 82
Alterations in the Blood-Ocular Barrier and Implications for Immune-Mediated Disease 83
Etiologic Implications of Inflammatory Exudates 83
Restoration of Homeostasis: Ocular Wound Healing 85
Germinal Cells 85
Tissue Scaffold 87
Adequate Nutrition 88
Diseases Resulting from Defective Wound Healing 88
Ocular Neoplasia 89
Clinical Signs Associated with Ocular Neoplasia 90
Hyphema 90
Glaucoma 90
Uveitis 90
Histologic Basis for Common Clinical Lesions 90
Corneal Edema 91
Corneal Pigmentation 91
Aqueous Flare 91
Keratic Precipitates 91
Hyphema 91
Changes in Pupil Shape 91
Changes in Iris Color 91
Lens Opacity 91
Retinal Pathologic Findings: Tapetal Hyper-reflectivity and Retinal Opacity 92
5 Diagnostic Techniques 93
Medical History 93
Examination Procedure 93
Assessment From A Distance 96
Assessment of Iris and Pupil 96
Retroillumination 96
Pupillary Light Reflexes 97
Other Commonly Performed Neuroophthalmic Tests 98
Menace Response 98
Dazzle Reflex 98
Palpebral Reflex 98
Examination of the Anterior Segment 98
Eyelids 99
Nasolacrimal Apparatus 100
Third Eyelid 100
Conjunctiva 100
Sclera 100
Clinical Differentiation of Episcleral and Conjunctival Hyperemia (or Injection) 101
Cornea 101
Anterior Chamber 101
Iris and Pupil 102
Lens 102
The Posterior Segment 102
The Normal Fundus 103
The Canine Fundus 104
The Feline Fundus 104
The Equine Fundus 105
The Fundus of Sheep, Goats, and Cattle 105
Ophthalmoscopy 106
Direct Ophthalmoscopy 106
Indirect Ophthalmoscopy 107
Monocular Indirect Ophthalmoscopy 107
Examination of the Posterior Segment 108
Vitreous 108
Retina 108
Optic Nerve 108
Additional Diagnostic Testing 109
Schirmer Tear Test and Phenol Red Thread Test 109
Tear Film Break-Up Time 109
Assessment of Aqueous Flare 110
Vital Dyes 110
Fluorescein 110
Rose Bengal 112
Tonometry 112
Indentation Tonometry 113
Applanation Tonometry 113
Rebound Tonometry 114
Normal Intraocular Pressure 114
Tonography 115
Gonioscopy 115
Ocular Surface Sampling 116
Sample Collection by Scraping, Swab, or Cytobrush 116
Microbiologic Samples 117
Cytologic Samples 117
Tests of Nasolacrimal Apparatus Patency 117
The Fluorescein Passage (or Jones) Test 117
Nasolacrimal Cannulation and Flushing 117
Dacryocystorhinography 118
Additional Neuroophthalmic Testing 118
The Swinging Flashlight Test 119
Oculocephalic Reflexes 119
Behavioral Testing of Vision 119
Electroretinography and Visual Evoked Potentials 120
Retinoscopy 120
Imaging Techniques 120
Radiography 120
Computed Tomography and Magnetic Resonance Imaging 120
Contrast Techniques 121
Ultrasonography 121
Fluorescein Angiography 122
6 Eyelids 124
Anatomy, Function, and General Pathologic Responses 124
Anatomy and Function 124
General Pathologic Responses 128
Premature or Delayed Opening of the Eyelids in Neonates 128
Eyelid Agenesis (Coloboma) 128
Prominent Nasal Skin Folds 129
Disorders of the Cilia 130
Clinical Signs of Cilia Disorders 131
Treatment of Distichiasis 131
Cryoepilation 132
Electroepilation 132
Treatment of Ectopic Cilia 132
Treatment of Trichiasis 133
Entropion 133
Clinical Signs of Entropion 134
Treatment of Entropion 134
Temporary “Tacking” Techniques 135
Injection Technique in Lambs 135
Wedge Resection 136
Hotz-Celsus Procedure 136
Combination Hotz-Celsus and Lateral Wedge Resection 136
Lateral Arrowhead Procedure and Tenotomy for Lateral Entropion 137
Medial Canthoplasty for Lower Medial Entropion and Brachycephalic Ocular Syndrome 137
Upper Eyelid Entropion 138
Ectropion 139
Treatment of Ectropion 139
Wedge Resection 139
“V-to-Y” Blepharoplasty 139
Eyelid Injuries 140
Treatment of Eyelid Injuries 140
Nonneoplastic Disorders of the Meibomian and Other Eyelid Glands 141
Chalazia 141
Hordeolum and Meibomian Adenitis 141
Neoplasia 142
Squamous Cell Carcinoma 143
Meibomian Adenoma 145
Feline Multiple Apocrine Hidrocystoma 145
Equine Sarcoid 145
Viral Papillomatosis 146
Mast Cell Tumors 146
Histiocytoma 146
Skin Diseases Affecting the Eyelids 146
7 Conjunctiva 154
Anatomy and Physiology 154
Conjunctival Wound Healing 155
Clinical Signs of Conjunctival Disease 155
Cellular Responses in Conjunctival Disease 155
Conjunctival Hyperemia 156
Chemosis (Conjunctival Edema) 156
Ocular Discharge 156
Conjunctival Swelling, Thickening, or Mass Formation 156
Conjunctival Ulceration 157
Follicle Formation 157
Pruritus 157
Conjunctivitis 157
Classification 157
Differential Diagnosis 157
Diagnostic Methods 158
Bacterial Culturing 158
Conjunctival Scrapings 159
Conjunctival Biopsy 159
General Treatment Considerations for Conjunctivitis 159
Antibiotics 160
Corticosteroids 160
Cleansing Agents 160
Topical Mast Cell Stabilizers and Antihistamines 160
Vasoactive Agents 160
Bacterial Conjunctivitis 160
Chlamydial Conjunctivitis 161
Treatment 162
Mycoplasmal Conjunctivitis 162
Treatment 162
Viral Conjunctivitis 162
Feline Viral Conjunctivitis 162
Canine Viral Conjunctivitis 163
Equine Viral Conjunctivitis 164
Bovine Viral Conjunctivitis 164
Treatment of Viral Conjunctivitis 164
Mycotic Conjunctivitis 167
Parasitic Conjunctivitis 167
Immune-Mediated Conjunctivitis 167
Allergic Conjunctivitis 167
Treatment of Immune-Mediated Conjunctivitis 168
Other Conjunctival Disorders 168
Drug Plaques 168
Conjunctival Lacerations 168
Ligneous Conjunctivitis 168
Lipogranulomatous Conjunctivitis 169
Conjunctival Neoplasia 169
Conjunctival Dermoid 169
Ocular Squamous Cell Carcinoma 170
Etiologic Factors 170
Clinical Signs and Pathogenesis 170
Differential Diagnosis 170
Treatment 171
Bovine Ocular Squamous Cell Carcinoma 171
Incidence 171
Treatment 171
Control 171
Canine Conjunctival Papillomatosis 171
Canine Mast Cell Tumors 171
Canine and Feline Conjunctival Vascular Tumors 171
Canine and Feline Melanocytic Tumors 172
Equine Conjunctival Angiosarcoma 172
8 Third Eyelid 173
Anatomy and Physiology 173
Examination 174
Clinical Signs of Third Eyelid Disease 174
Structural Abnormalities of the Third Eyelid 174
Amelanotic Leading Edge of the Third Eyelid 174
Scrolling or Eversion of the Third Eyelid 174
Treatment 175
Prolapse of the Gland of the Third Eyelid (Cherry Eye) 175
Treatment 175
Neoplasms Affecting the Third Eyelid 176
Trauma to the Third Eyelid 178
Inflammatory Disorders of the Third Eyelid 178
9 Lacrimal System 179
Anatomy and Physiology 179
Lacrimal and Third Eyelid Glands 179
Accessory Lacrimal Glands 179
Precorneal Tear Film 180
Mucous Threads 181
Blinking 181
Lacrimal Puncta, Canaliculi, and Nasolacrimal Duct 182
Innervation 182
Disturbances of Lacrimal Function 183
Effects of Precorneal Tear Film Dysfunction 183
Examination 183
Disorders Characterized by Epiphora 184
Dacryocystitis 184
Clinical Signs. 184
Diagnosis. 184
Treatment. 184
Nasolacrimal Catheterization. 184
Dacryocystotomy. 184
Congenital Atresia, Ectopia, and Imperforate Puncta 185
Cystic Disorders 186
Cicatricial Nasolacrimal Obstructions 186
Conjunctivorhinostomy. 187
Conjunctivobuccostomy. 187
Tear-Staining Syndrome in Dogs 187
Treatment. 188
Other Causes of Epiphora 189
Deficiency of the Precorneal Tear Film 189
Mucin Deficiency 189
Lipid Deficiency 189
Deficiency of the Aqueous Layer 190
Keratoconjunctivitis Sicca 190
Etiologic Factors. 190
Drug-Induced. 190
Surgically Induced. 190
Immune Mediated. 190
Idiopathic. 190
Orbital and Supraorbital Trauma. 190
Infectious. 190
Locoweed Poisoning. 190
Other Causes. 190
Congenital. 190
Senile Atrophy. 191
Radiation. 191
Neurogenic. 191
Pathologic Changes. 191
Breed Predisposition. 191
Clinical Signs. 191
Mucoid and Mucopurulent Discharge. 191
Blepharospasm. 191
Corneal Ulceration. 191
Corneal Vascularization and Pigmentation. 191
Dry, Lusterless Cornea. 192
Dry Ipsilateral Nostril. 192
Chronic Staphylococcal Blepharitis. 192
Diagnosis. 192
Natural Course of the Disease. 192
Treatment. 192
Medical Therapy. 192
Stimulate Natural Tear Production. 192
Replacement of the Precorneal Tear Film. 193
Reduce Ocular Surface Inflammation. 194
Control Secondary Infection. 194
Removal of Excess Mucus. 194
Initial Treatment Plan and Follow-up. 194
Surgical Therapy 195
Parotid Duct Transposition. 195
Postoperative Treatment. 195
Operative and Postoperative Complications. 195
Neoplasia 197
10 Cornea and Sclera 198
Anatomy, Physiology, and Wound Healing 198
Cornea 198
Normal Corneal Healing 200
Epithelium 200
Stroma 200
Endothelium and Descemet’s Membrane 200
Effects of Corticosteroids on Corneal Healing 201
Sclera 201
Pathologic Responses 201
Corneal Edema 202
Corneal Vascularization 203
Corneal Fibrosis 204
Corneal Melanosis 204
Stromal Infiltration with White Blood Cells 206
Deposition of Abnormal Substances (Especially Lipid or Mineral) within the Cornea 206
Stromal Malacia (or “Melting”) 207
Corneal Diseases Present at Birth and Corneal Dystrophies 207
Microcornea 207
Dermoid 207
Persistent Pupillary Membranes 208
Corneal Epithelial Dysmaturation or “Puppy Dystrophy” 208
Corneal Lipid Dystrophy 209
Corneal Endothelial Dystrophy 209
Superficial Punctate Keratitis 209
Corneal Ulcers and Erosions in All Species 209
Common Causes of Corneal Ulceration or Erosion 210
Simple versus Complicated Ulcers and Erosions 210
General Principles of Corneal Ulcer and Erosion Treatment 211
Antibiotics 211
Mydriatic Therapy 212
Analgesic and Antiinflammatory Agents 212
Prevention of Self-trauma 212
Temporary Tarsorrhaphy versus Third Eyelid Flap 212
Treatment of Uncomplicated (Simple) Corneal Ulcers and Erosions 213
Treatment of Deep (Stromal) Corneal Ulcers or Descemetoceles 213
Cyanoacrylate Adhesives (Tissue Glue) 215
Protease Inhibitors 216
Corneal Trauma and Foreign Bodies 216
Corneal Lacerations 216
Removal of Corneal Foreign Bodies 217
Epithelial Inclusion Cysts 217
Neurogenic Keratitis 218
“Florida Keratopathy” or “Florida Spots” 218
Corneal Disease of Dogs 218
Pigmentary Keratitis 218
“Pannus” or Chronic Immune-Mediated Superficial Keratoconjunctivitis 219
Indolent Corneal Ulcers and Erosions 220
Canine Herpesvirus 222
Infectious Canine Hepatitis 222
Corneal Disease of Cats 222
Feline Herpetic Keratitis 223
Feline Eosinophilic Keratoconjunctivitis 223
Feline Corneal Sequestration 224
Acute Bullous Keratopathy 224
Ulcerative Mycoplasmal Keratitis 225
Mycobacterial Keratitis 225
Corneal Disease of Horses 225
Equine Fungal Keratitis 225
Stromal Abscesses 227
Equine Eosinophilic Keratoconjunctivitis 228
Chronic Superficial Corneal Ulcers and Erosions in Horses 228
Corneal Disease of Ruminants 228
Infectious Bovine Keratoconjunctivitis 229
Infectious Bovine Rhinotracheitis 230
Malignant Catarrhal Fever 230
Scleral and Limbal Disorders 230
Colobomatous Defects 230
Scleritis and Episcleritis 231
Scleral Trauma 232
Limbal Neoplasia 232
11 Uvea 234
Anatomy and Physiology 234
Iris 234
Ciliary Body 235
Choroid 236
Blood-Ocular Barrier 239
Pathologic Reactions 240
Definitions 240
Immune Mechanisms 240
Congenital Uveal Abnormalities 241
Abnormalities of the Pupil 241
Persistent Pupillary Membrane 241
Coloboma 241
Anterior Segment Dysgenesis 241
Disorders of Pigmentation 242
Heterochromia 242
Iris Nevus 243
Waardenburg Syndrome 243
Uveitis 243
Clinical Signs 243
Sequelae of Uveitis 243
Posterior Synechiae 243
Peripheral Anterior Synechiae 244
Cataract 244
Glaucoma 244
Retinal Detachment 244
Atrophy 244
Preiridal Fibrovascular Membranes 244
Cyclitic Membranes 244
Diagnosis of Uveitis 244
General Therapeutic Principles 245
1. Make an Etiologic Diagnosis 245
2. Control Inflammation 245
Corticosteroids. 245
Nonsteroidal Antiinflammatory Drugs. 247
Immunosuppressive Agents. 247
3. Prevent Undesirable Sequelae 247
Mydriatics and Cycloplegics. 247
Antiglaucoma Drugs. 247
4. Relieve Pain 247
Specific Forms of Uveitis 247
Infectious Uveitis 247
Immune-Mediated Uveitis 248
Uveodermatologic Syndrome. 248
Lens-Induced Uveitis. 248
Leakage through the Intact Lens Capsule. 248
Penetrating Lens Injuries. 248
Uveitis Associated with Dental Disease. 249
Golden Retriever Uveitis. 249
Feline Uveitis. 249
Equine Recurrent Uveitis. 249
History and Geographic Distribution. 250
Etiologic Factors. 250
Leptospira-Associated Uveitis. 250
Clinical Signs of ERU. 251
Active Phase. 251
Quiescent Phase. 251
Treatment. 251
Onchocerca Uveitis. 254
Treatment. 254
Phacoclastic Uveitis in Rabbits. 254
Toxic Uveitis. 255
Trauma 255
Traumatic Uveitis 255
Iris Prolapse 255
Signs 255
Treatment 255
Visual Outcome and Ocular Survival after Iris Prolapse in Horses 255
Hyphema 256
Etiologic Factors 256
Treatment 256
Additional Therapy for Mild Hyphema 256
Additional Therapy for Severe Hyphema 256
Recurrent Hyphema 256
Uveal Cysts and Neoplasms 256
Uveal Cysts 257
Cystic Corpora Nigra in Horses 257
Primary Tumors 257
Adenocarcinoma and Adenoma 257
Melanocytoma and Melanoma 258
Clinical Signs. 258
Treatment. 258
Ocular Melanosis of Cairn Terriers 258
Feline Diffuse Iris Melanoma 259
Primary Feline Ocular Sarcomas 259
Secondary Tumors 259
Lymphosarcoma 259
Miscellaneous Disorders 260
Iris Hypoplasia 260
Iris Atrophy 260
Primary Iris Atrophy 260
Secondary Iris Atrophy 260
Senile Iris Atrophy 260
12 The Glaucomas 261
Aqueous Production and Drainage 261
Balancing Aqueous Production and Outflow 262
Causes of Variations in Intraocular Pressure 262
Diurnal Variation 262
Age 262
Blood Flow 263
Drugs 263
Ocular Inflammation 263
Diagnostic Methods 263
Tonometry 263
Ophthalmoscopy 263
Gonioscopy 263
Clinical Signs 265
Increased Intraocular Pressure 265
Pain, Blepharospasm, and Altered Behavior 265
Engorged Episcleral Vessels 265
Corneal and Scleral Changes 266
Edema 266
Buphthalmos and Descemet’s Streaks 266
Changes in Anterior Chamber Depth 266
Fixed Dilated Pupil 266
Lens Changes 267
Fundus Changes 268
Impaired Vision 268
Optic Disc Cupping 268
Retinal Degeneration 269
Classification 271
Pathogenesis 274
Primary Open-Angle Glaucoma 274
Primary Angle-Closure Glaucoma 274
Secondary Glaucomas 276
Obstruction of the Iridocorneal Angle 276
Pupillary Block 276
Ciliary Body–Vitreous–Lens Block 276
Combined-Mechanism Glaucoma 278
Treatment 278
Emergency Treatment of Acute Glaucoma 279
Long-Term Management of Glaucoma 279
Surgical Therapy for Glaucoma 280
Surgery to Increase Aqueous Humor Outflow 280
Surgery to Reduce Aqueous Humor Production 281
Cyclocryotherapy 281
Laser Cyclophotocoagulation 282
Combined Procedures 282
Lens Luxation 282
Glaucoma Secondary to Uveitis 283
Glaucoma Secondary to Intraocular Neoplasia 283
Absolute Glaucoma 283
Evisceration with Intrascleral Prosthesis 283
Enucleation 284
Feline Glaucoma 284
Equine Glaucoma 285
13 Lens 286
Anatomy and Physiology 286
Lens Components 286
Capsule 286
Lens Epithelium 287
Lens Fibers 287
Metabolism and Composition 287
Nuclear Sclerosis 289
Congenital Anomalies 289
Cataract 290
Molecular and Cellular Pathogenesis of Cataracts 290
Classification 291
Degree of Opacity and Maturation 291
Causes of Cataracts 293
Hereditary Cataracts 293
Congenital Cataracts 293
Diabetic Cataracts 294
Acquired Cataracts 295
Senile Cataracts 296
Diagnosis 296
History 296
Clinical Signs 296
Lens-Induced Uveitis 297
Treatment of Cataract 297
Medical Therapy 297
Surgical Case Selection 298
Surgical Correction 298
Discission and Aspiration. 298
Intracapsular Extraction. 298
Extracapsular Extraction. 299
Phacoemulsification. 299
Postoperative Vision and IOL Implantation 299
Complications, Postoperative Care, and Prognosis 300
Cataracts in Horses 301
Lens Luxation 301
Etiology 301
Clinical Signs and Diagnosis 302
Treatment 304
14 Vitreous 305
Anatomy and Physiology 305
Anatomy 305
Composition 306
Function 306
Pathologic Reactions 306
Congenital and Developmental Abnormalities 307
Persistent Hyaloid Artery 307
Persistent Tunica Vasculosa Lentis 307
Persistent Hyperplastic Tunica Vasculosa Lentis/Persistent Hyperplastic Primary Vitreous 307
Acquired Disorders 308
Vitreous Degeneration 308
Vitreous Hemorrhage 308
Infection and Inflammation 309
Vitreous Opacities (Floaters) 309
Asteroid Hyalosis and Synchysis Scintillans 309
Vitreous Mass 310
Role of the Vitreous in the Pathogenesis of Ocular Diseases 310
Vitreous and Lens Luxation 310
Aqueous Humor Misdirection Syndrome 310
Retinal Detachment 310
Surgical and Diagnostic Procedures 311
Hyalocentesis 311
Vitrectomy 311
Advanced Vitreoretinal Surgical Techniques 311
15 Retina 313
Cellular Anatomy 313
Blood Supply 316
Physiology and Biochemistry 317
Rods and Cones 317
Visual Photopigments 319
Photochemistry 321
Dark Adaptation 321
Electroretinography 321
Applied Anatomy (Ophthalmoscopic Variations) 324
Tapetum 324
Nontapetum 324
Optic Disc 325
Blood Vessels 326
Myelination of Nerve Fiber Layer 327
Pathologic Mechanisms 327
Ischemia 327
Retina-Optic Nerve Interaction 328
Interactions with Choroid 328
Primary Photoreceptor Disease 328
Reactions of Pigment Epithelium 328
Perivascular Cuffing 330
Retinal Hemorrhages 330
Gliosis 330
Congenital Retinal Disorders 331
Retinal Dysplasia 331
Collie Eye Anomaly 332
Coloboma 334
Retinopathy 334
Inherited Retinopathies 334
Classification of Inherited Retinopathies 335
Age of Onset. 335
Affected Cells. 335
Mode of Inheritance. 335
Genetic and Molecular Pathogenesis. 335
Clinical Signs 335
Progressive Loss of Vision. 335
Tapetal Hyperreflectivity. 337
Retinal Blood Vessels. 337
Optic Disc. 337
Nontapetal Fundus. 337
Pupils. 337
Cataracts. 337
Additional Diagnostic Testing 337
Treatment 338
Specific Forms of Inherited Retinopathy 339
Hemeralopia. (Achromatopsia). 339
Retinal Pigment Epithelium Dystrophy. 339
Congenital Stationary Night Blindness. 339
Canine Multifocal Retinopathy. 340
Retinal Dystrophy in Briards. 340
Inherited Retinal Degenerations in Cats. 340
Acquired Retinopathies 340
Retinopathy Secondary to Cardiovascular Diseases 340
Retinopathy Secondary to Infectious and Inflammatory Diseases 341
Active Chorioretinitis. 341
Inactive Chorioretinitis. 343
Specific Retinopathies 343
Glaucomatous Retinopathy 343
Uveodermatologic Syndrome 343
Sudden Acquired Retinal Degeneration 343
Miscellaneous Causes of Retinopathy 343
Nutritional Causes 343
Feline Central Retinal Degeneration. 343
Hypovitaminosis A. 344
Storage Diseases 344
Drug and Plant Toxicities 344
Ivermectin Toxicity. 344
Enrofloxacin Toxicity in Cats. 345
Plant Poisonings in Food Animals. 345
Oxygen Toxicity in Cats and Dogs. 345
Retinal Detachment 345
Etiologic Factors 345
Signs 346
Therapy 346
16 Neuroophthalmology 348
Nerve Supply of the Eye and Adnexa 348
Optic Nerve (Cranial Nerve II) 348
Oculomotor Nerve (Cranial Nerve III) 348
Trochlear Nerve (Cranial Nerve IV) 349
Trigeminal Nerve (Cranial Nerve V) 349
Abducent Nerve (Cranial Nerve VI) 350
Facial Nerve (Cranial Nerve VII) 350
Assessing Vision and Pupillary Light Reflexes 350
Vision and the Menace Response 350
Tracking Moving Objects 353
Maze Test 353
Visual Placing Response 353
Pupillary Light Reflex 353
The Anatomic Basis of the Pupillary Light Reflex 353
Testing the Pupillary Light Reflex 354
Swinging Flashlight Test 355
Dazzle Reflex 355
Electrophysiology 356
Lesions in Patients with Visual and Pupillary Light Reflex Deficits 356
Lesions in Blind Patients with Normal Pupillary Light Reflexes 356
Lesions in Blind Patients with Abnormal Pupillary Light Reflexes 356
Pupils in Patients with Intracranial Injury 360
Lesions Causing Pupillary Light Reflex Abnormalities in Visual Patients 362
Additional Causes of Pupillary Light Reflex Abnormalities 363
Extraocular Muscles and Lesions Causing Strabismus 363
Function of the Extraocular Muscles 363
Lesions Causing Strabismus 364
Strabismus Caused by Disorders of the Vestibular System 364
Strabismus Caused by Lesions in Innervation of the Extraocular Muscles 364
Oculomotor Paralysis. 364
Abducens Paralysis. 365
Trochlear Paralysis. 365
Lesions of Additional Cranial Nerves 365
Facial Nerve Paralysis 365
Causes of Facial Nerve Paralysis and Other Associated Signs 366
Trigeminal Nerve Dysfunction 367
Lesions Causing Eyelid Abnormalities 367
Third Eyelid Abnormalities 367
Protrusion of the Third Eyelid 367
Horner’s Syndrome. 367
Tetanus. 367
Facial Nerve Paralysis. 368
Haws Syndrome. 368
Dysautonomia. 368
Congenital Myotonia. 368
Nonneurogenic Causes. 368
Lesions Causing Abnormalities of the Palpebral Fissure 368
Innervation of the Upper Eyelid 368
Lesions Increasing the Size of the Palpebral Opening 368
Lesions Decreasing the Size of the Palpebral Opening 369
Autonomic Innervation and Abnormalities 369
Parasympathetic Lower Motor Neuron Innervation 370
Sympathetic Lower Motor Neuron Innervation 370
Diseases of the Sympathetic System 370
Horner’s Syndrome 370
Clinical Signs. 370
Etiologic Factors. 371
Diagnosis. 372
Treatment. 373
Dysautonomia (Key-Gaskell Syndrome). 373
Clinical Signs. 373
Diagnosis. 373
Demonstration of Parasympathetic Denervation. 373
Demonstration of Sympathetic Denervation. 374
Treatment. 374
Vestibular System and Nystagmus 374
Nystagmus 374
Normal Vestibular Nystagmus 374
Disorders of the Vestibular System 375
Eye Position in Vestibular Disease 375
Loss of Normal Nystagmus 375
Pathologic Nystagmus 375
Diseases Causing Pathologic Nystagmus 375
Otitis Media and Otitis Interna. 375
Idiopathic Vestibular Disease (Feline Vestibular Syndrome, Idiopathic Benign Vestibular Disease, Old Dog Vestibular Disease). 375
Central Disorders. 376
Congenital Nystagmus. 376
Diseases of the Central Visual Pathways 376
Diseases of the Optic Nerve 376
Congenital Anomalies 376
Aplasia and Hypoplasia. 376
Colobomas. 377
Inflammatory Disorders 377
Optic Neuritis. 377
Etiologic Factors. 377
Clinical Signs. 377
Differential Diagnosis. 378
Treatment. 378
Exudative Optic Neuritis and Optic Neuropathy in Horses. 378
Neoplasms 379
Clinical Signs. 380
Diagnosis and Treatment. 380
Optic Neuropathy 380
Etiologic Factors. 380
Clinical Signs. 381
Treatment. 381
Papilledema 381
Clinical Signs. 381
Diseases of the Optic Chiasm 381
Diseases of the Optic Tracts 382
Bilateral Disease 382
Unilateral Disease 382
Diseases of the Lateral Geniculate Nucleus 382
Diseases of the Optic Radiations and Visual Cortex 382
Unilateral Disease 382
Neoplastic Lesions. 382
Traumatic Lesions. 382
Feline Ischemic Encephalopathy. 382
Unilateral Cerebral Abscess. 383
Encephalitis. 383
Bilateral Disease 383
Congenital Causes 383
Hypoplasia of the Prosencephalon in Calves. 383
Hydranencephaly. 383
Obstructive Hydrocephalus. 383
Acquired Causes 383
Canine Distemper. 383
Thromboembolic Meningoencephalitis. 383
Metabolic Diseases. 383
Ischemic Necrosis of Cerebrum. 383
Poisonings in Cattle and Sheep. 383
Additional Neuroophthalmic Diseases 384
Granulomatous Meningoencephalitis 384
Vitamin A Deficiency 384
Storage Diseases 384
Cerebellar Disease 385
17 Orbit 386
Anatomy 386
Extraocular Muscles 390
Pathologic Mechanisms 390
Diagnostic Methods 392
Localization of Foreign Bodies 392
Orbital Diseases 393
Orbital Cellulitis and Orbital Abscess 393
Clinical Signs. 394
Treatment. 394
Cystic Orbital and Periocular Lesions 396
Frontal Sinus Mucocele 396
Zygomatic Mucocele 396
Clinical Signs. 397
Treatment. 397
Neoplasms and Space-Occupying Lesions 397
Clinical Signs. 397
Treatment. 398
Multilobular Osteoma 398
Periorbital Fractures 398
Masticatory Muscle Myositis 399
Extraocular Muscle Myositis 399
Orbital Emphysema 399
Proptosis of the Globe 399
Ophthalmic Manifestations of Dental Disease 399
Surgical Procedures 399
Enucleation 400
Indications. 400
Lateral Subconjunctival Enucleation Technique 401
Insertion of an Intraorbital Prosthesis 403
Transpalpebral Enucleation-Exenteration Technique 403
Enucleation in Birds 404
Exenteration 404
Ocular Prostheses 404
Intrascleral Prosthesis 404
Extrascleral (Shell) Prosthesis 405
Orbitotomy and Orbitectomy 407
18 Ocular Manifestations of Systemic Diseases 408
Ocular Manifestations of Systemic Diseases in Dogs and Cats (Tables 18-1 to 18-16) 408
Infectious Diseases 408
Canine Viral Diseases 408
Canine Distemper. 408
Infectious Canine Hepatitis. 409
Canine Herpes Virus. 410
Feline Viral Diseases 410
Feline Herpesvirus Infection. 410
Feline Calicivirus Infection. 413
Feline Leukemia Virus Infection. 414
Feline Immunodeficiency Virus Infection. 415
Feline Infectious Peritonitis. 416
Canine Bacterial Diseases 417
Brucellosis. 417
Borreliosis (Canine Lyme Disease). 418
Rickettsiosis (Rocky Mountain Spotted Fever and Ehrlichiosis). 419
Rocky Mountain Spotted Fever. 419
Canine Monocytic Ehrlichiosis. 419
Bacterial Diseases of Dogs and Cats 420
Bartonellosis. 420
Feline Bacterial Diseases 421
Chlamydiosis (Chlamydophilosis). 421
Mycoplasmosis. 421
Mycotic Diseases of Dogs and Cats 422
Blastomycosis. 422
Coccidioidomycosis. 426
Cryptococcosis. 426
Histoplasmosis. 427
Parasitic Diseases of Dogs and Cats 427
Toxoplasmosis. 427
Canine Parasitic Diseases 428
Neosporosis. 428
Visceral Leishmaniasis. 428
Endocrine Diseases 429
Endocrine Diseases of Dogs and Cats 429
Diabetes Mellitus. 429
Canine Endocrine Diseases 430
Hyperadrenocorticism. 430
Hypothyroidism. 430
Metabolic Diseases of Dogs and Cats 431
Hyperlipidemia. 431
Cardiovascular Diseases of Dogs and Cats 431
Thrombocytopenia and Thrombopathy (Thrombasthenia). 431
Systemic Hypertension. 432
Polycythemia. 433
Hyperviscosity Syndrome. 433
Immune-Mediated Diseases in Dogs 435
Uveodermatologic Syndrome (Vogt-Koyanagi-Harada–like Syndrome). 435
Idiopathic Diseases in Dogs 435
Sudden Aquired Retinal Degeneration. 435
Ocular Manifestations of Systemic Diseases in Horses (Tables 18-21 to 18-32) 436
Infectious Diseases 436
Viral Respiratory Diseases 436
Equine Herpesvirus (Rhinotracheitis or Rhinopneumonitis). 436
Equine Viral Arteritis. 436
Equine Influenza. 436
Other Viral Diseases. 437
Bacterial Diseases 437
Leptospirosis. 437
Strangles. 438
Salmonellosis. 439
Lyme Disease. 439
Protozoal Diseases 439
Babesiosis (Piroplasmosis). 439
Potomac Horse Fever. 439
Parasitic Diseases 440
Habronemiasis. 440
Cutaneous Onchocerciasis. 441
Adult Nematode Infections of the Eye. 442
Neurologic Diseases 442
Equine Protozoal Myeloencephalitis. 442
Viral Encephalitis. 442
Meningitis. 443
Photic Head Shaking in Horses. 443
Neuromuscular Diseases 443
Tetanus. 443
Botulism (Shaker Foal or Forage Poisoning). 443
Equine Motor Neuron Disease. 443
Miscellaneous Diseases 444
Lymphoma (Lymphosarcoma). 444
Severe Blood Loss. 444
Lightning Strike 444
Grass Sickness (Equine Dysautonomia). 444
Neonatal Diseases 444
Acquired Entropion. 444
Prematurity. 445
Sepsis and Failure of Passive Transfer. 445
Hypoxic Ischemic Encephalopathy. 445
Neonatal Isoerythrolysis. 446
Rhodococcus Equi Infection. 446
Ocular Manifestations of Systemic Diseases in Ruminants (See Tables 18-21 to 18-32) 446
Infectious Diseases 446
Bacterial Diseases 446
Listeriosis. 446
Ovine Chlamydial Polyarthritis and Conjunctivitis. 446
Mycoplasmal Keratoconjunctivitis in Goats and Sheep. 447
Thromboembolic Meningoencephalitis. 447
Mannheimia (Pasteurella) Pneumonia. 447
Tuberculosis. 447
Septicemia. 447
Viral Diseases 448
Arthrogryposis-Hydrencephaly. 448
Bluetongue. 448
Infectious Bovine Rhinotracheitis. 448
Malignant Catarrhal Fever. 449
Bovine Viral Diarrhea. 449
Maedi-Visna. 449
Protozoal Diseases 449
Babesiosis and Trypanosomiasis. 449
Toxoplasma Gondii Infection. 449
Other Infectious Diseases 449
Scrapie. 449
Coenurosis. 450
Miscellaneous Diseases 450
Lymphosarcoma. 450
Polioencephalomalacia. 450
Toxic Plants. 450
Vetch Toxicity. 450
19 Ocular Emergencies 451
Basic Materials Required to Address Ocular Emergencies 451
Basic Diagnostic Instruments and Supplies 451
Surgical Instruments 451
Medications 451
Proptosis of the Globe 451
Prognosis 452
Avulsion of Extraocular Muscles 452
Hyphema 453
Pupils 453
Skull Conformation 453
Postoperative Therapy 453
Severe Ocular and Adnexal Contusions and Concussion 453
Common Clinical Signs Associated with Ocular Trauma 454
Penetrating Injuries of the Globe 455
Lid Lacerations 455
Treatment 455
Important Facts 456
Corneal Lacerations 456
Severe Corneal Ulceration 456
Glaucoma 457
Interim Therapy 457
Hyphema 457
Acute Anterior Uveitis 457
Acute Anterior Lens Luxation 458
Sudden Blindness 458
20 Ophthalmology of Exotic Pets 459
Ophthalmic Examination and Diagnostic Testing 459
Rabbits 460
Ophthalmic Anatomy 460
Orbital Disease 460
Adnexal Disease 461
Conjunctival Disease 461
Nasolacrimal Disease 462
Corneal Disease 462
Cataract 463
Glaucoma 464
Ferrets 464
Ophthalmic Anatomy 464
Orbital Disease 464
Conjunctival Disease 464
Cataract 465
Mice and Rats 465
Ophthalmic Anatomy 465
Nasolacrimal Disease 465
Corneal Disease 466
Cataract 466
Retinal Disease 466
Chinchillas 466
Ophthalmic Anatomy 466
Ophthalmic Disease 467
Guinea Pigs 467
Ophthalmic Anatomy 467
Adnexal Disease 467
Surface Ocular Disease 468
Corneal Disease 468
Conjunctival Disease 468
Intraocular Disease 468
Cataract 468
Heterotopic Bone 468
Raptors and Pet Birds 469
Ophthalmic Anatomy 469
Ophthalmic Disease 469
Trauma 469
Conjunctival Disease 470
Lizards, Turtles, Tortoises, and Crocodilians 471
Ophthalmic Anatomy 471
Ophthalmic Disease 471
Snakes 472
Ophthalmic Anatomy 472
Diseases of the Spectacle 473
Amphibians 474
Ophthalmic Anatomy 474
Ophthalmic Disease 474
Appendix Breed Predisposition to Eye Disorders* 477
Dogs 477
Afghan Hound 477
Airedale 477
Akbash 477
Akita 477
Alaskan Malamute 477
American Cocker Spaniel 477
American Eskimo Dog 478
American Pit Bull Terrier 478
American Staffordshire Terrier 478
American Water Spaniel 478
Australian Cattle Dog (Queensland Heeler or Blue Heeler) 478
Australian Shepherd 478
Australian Terrier 478
Basenji 478
Basset Hound 478
Beagle 478
Bearded Collie 478
Bedlington Terrier 478
Belgian Malinois 479
Belgian Sheepdog (Belgian Shepherd—Groenendael) 479
Belgian Tervuren 479
Bernese Mountain Dog 479
Bichon Frise 479
Black and Tan Coonhound 479
Bloodhound 479
Border Collie 479
Border Terrier 479
Borzoi 479
Boston Terrier 479
Bouvier des Flandres 480
Boxer 480
Boykin Spaniel 480
Briard 480
Brittany Spaniel 480
Brussels Griffon 480
Bull Mastiff 480
Bull Terrier 480
Cairn Terrier 480
Cardigan Welsh Corgi 480
Cavalier King Charles Spaniel 481
Chesapeake Bay Retriever 481
Chihuahua 481
Chinese Crested 481
Chow Chow 481
Clumber Spaniel 481
Collie (Rough and Smooth) 481
Coonhound 481
Corgi 481
Coton de Tulear 481
Curly Coated Retriever 482
Dachshund (All Varieties) 482
Dalmatian 482
Dandie Dinmont Terrier 482
Doberman Pinscher 482
English Bulldog 482
English Cocker Spaniel 482
English Setter 482
English Springer Spaniel 482
English Toy Spaniel (King Charles, Prince Charles, Ruby, Blenheim) 483
Entlebucher 483
Field Spaniel 483
Flat Coated Retriever 483
Fox Terrier (Smooth) 483
Fox Terrier (Wirehaired) 483
French Bulldog 483
German Shepherd 483
German Shorthaired Pointer 483
German Wirehaired Pointer 483
Giant Schnauzer 484
Golden Retriever 484
Gordon Setter 484
Great Dane 484
Great Pyrenees 484
Greater Swiss Mountain Dog 484
Greyhound 484
Havanese 484
Irish Setter 484
Irish Water Spaniel 484
Irish Wolfhound 485
Italian Greyhound 485
Jack Russell Terrier 485
Japanese Chin 485
Keeshond 485
Kerry Blue Terrier 485
Komondor 485
Kuvasz 485
Labrador Retriever 485
Lakeland Terrier 485
Leonberger 485
Lhasa Apso 486
Löwchen 486
Maltese Terrier 486
Manchester Terrier 486
Mastiff 486
Miniature Australian Shepherd 486
Miniature Bull Terrier 486
Miniature Pinscher 486
Miniature Schnauzer 486
Newfoundland 486
Norfolk Terrier 487
Norwegian Buhund 487
Norwegian Elkhound 487
Norwich Terrier 487
Nova Scotia Duck Tolling Retriever 487
Old English Sheepdog 487
Papillon 487
Parson Russell Terrier 487
Pekingese 487
Pembroke Welsh Corgi 487
Petit Basset Griffon Vendéen 487
Pointer 488
Polish Lowland Sheepdog 488
Pomeranian 488
Poodle (All Varieties) 488
Portuguese Water Dog 488
Pug 488
Puli 488
Queensland Blue Heeler 488
Rat Terrier 488
Redbone Coonhound 488
Rhodesian Ridgeback 488
Rottweiler 488
Saint Bernard 489
Saluki 489
Samoyed 489
Schipperke 489
Scottish Terrier 489
Sealyham Terrier 489
Shar-Pei 489
Shetland Sheepdog (Sheltie) 489
Shiba Inu 489
Shih Tzu 489
Siberian Husky 490
Silky Terrier 490
Skye Terrier 490
Smooth Fox Terrier 490
Soft-Coated Wheaten Terrier 490
Spinone Italiano 490
Spitz 490
Staffordshire Bull Terrier 490
Standard Schnauzer 490
Sussex Spaniel 490
Swedish Vallhund 490
Tibetan Spaniel 490
Tibetan Terrier 491
Toy Havanese 491
Toy Terrier 491
Vizsla 491
Weimaraner 491
Welsh Springer Spaniel 491
Welsh Terrier 491
West Highland White Terrier 491
Whippet 491
Wire Fox Terrier 491
Yorkshire Terrier 491
Cats 491
Abyssinian 491
Albinotic Felidae 491
Birman 491
Burmese 491
Domestic Shorthair 492
Himalayan 492
Korat 492
Manx 492
Persian 492
Siamese 492
Cattle 492
Aberdeen Angus 492
Ayrshire 492
Beef Master 492
Brahman 492
Brown Swiss 492
Charolais 492
Devon 492
Friesian (Holstein) 492
German Spotted 492
Guernsey 492
Hereford 492
Jersey 492
Shorthorn 493
Simmental 493
Sheep 493
Corriedale 493
Hampshire Downs 493
New Zealand Romney 493
Piebald 493
Shropshire 493
Southdown 493
South Hampshire 493
Suffolk 493
Horses 493
Appaloosa 493
Arabian 493
Belgian 493
Clydesdale 493
Lipizzaner 493
Morgan 493
Quarter Horse 493
Rocky Mountain Horse 493
Shire 493
Thoroughbred 493
Goat 493
Angora 493
Pigs 493
Miniature Swine 493
Pot-Bellied 493
Yorkshire 493
Glossary 495
Index 505
A 505
B 505
C 506
D 508
E 509
F 510
G 511
H 511
I 512
J 512
K 512
L 513
M 513
N 514
O 515
P 515
R 516
S 517
T 518
U 519
V 519
W 520
X 520
Y 520
Z 520