Ophthalmology : a short textbook

1.1 Equipment . . . 1 1.2 History . . . 3 1.3 Visual Acuity . . . 4 1.4 Ocular Motility . . . 5 1.5 Binocular Alignment . . . 6 1.6 Examination of the Eyelids and Nasolacrimal Duct . . . 7 1.7 Examination of the Conjunctiva . . . 7 1.8 Examination of the Cornea . . . 10 1.9 Examination of the Anterior Chamber . . . 11 1.10 Examination of the Lens . . . 12 1.11 Ophthalmoscopy . . . 13 1.12 Confrontation Field Testing . . . 14 1.13 Measurement of Intraocular Pressure . . . 15 1.14 Eyedrops, Ointment, and Bandages . . . 15 2 The Eyelids . . . 17 (Peter Wagner, Gerhard K. Lang) 2.1 Basic Knowledge . . . 17 2.2 Examination Methods . . . 19 2.3 Developmental Anomalies . . . 20 2.3.1 Coloboma . . . 20 2.3.2 Epicanthal Folds . . . 21 2.3.3 Blepharophimosis . . . 21 2.3.4 Ankyloblepharon . . . 22 2.4 Deformities . . . 22 2.4.1 Ptosis . . . 22 2.4.2 Entropion . . . 24 2.4.3 Ectropion . . . 28 2.4.4 Trichiasis . . . 30 Lang, Ophthalmology © 2000 Thieme All rights reserved. Usage subject to terms and conditions of license. VII 2.4.5 Blepharospasm . . . 30 2.5 Disorders of the Skin and Margin of the Eyelid . . . 30 2.5.1 Contact Eczema . . . 30 2.5.2 Edema . . . 31 2.5.3 Seborrheic Blepharitis . . . 33 2.5.4 Herpes Simplex of the Eyelids . . . 34 2.5.5 Herpes Zoster Ophthalmicus . . . 35 2.5.6 Eyelid Abscess . . . 36 2.5.7 Tick Infestation of the Eyelids . . . 37 2.5.8 Louse Infestation of the Eyelids . . . 37 2.6 Disorders of the Eyelid Glands . . . 38 2.6.1 Hordeolum . . . 38 2.6.2 Chalazion . . . 39 2.7 Tumors . . . 40 2.7.1 Benign Tumors . . . 40 2.7.1.1 Ductal Cysts . . . 40 2.7.1.2 Xanthelasma . . . 40 2.7.1.3 Molluscum Contagiosum . . . 42 2.7.1.4 Cutaneous Horn . . . 42 2.7.1.5 Keratoacanthoma . . . 42 2.7.1.6 Hemangioma . . . 43 2.7.1.7 Neurofibromatosis (Recklinghausen’s Disease) . . . 44 2.7.2 Malignant Tumors . . . 45 2.7.2.1 Basal Cell Carcinoma . . . 45 2.7.2.2 Squamous Cell Carcinoma . . . 47 2.7.2.3 Adenocarcinoma . . . 47 3 Lacrimal System . . . 49 (Peter Wagner, Gerhard K. Lang) 3.1 Basic Knowledge . . . 49 3.2 Examination Methods . . . 52 3.2.1 Evaluation of Tear Formation . . . 52 3.2.2 Evaluation of Tear Drainage . . . 53 3.3 Disorders of the Lower Lacrimal System . . . 57 3.3.1 Dacryocystitis . . . 57 3.3.1.1 Acute Dacryocystitis . . . 57 3.3.1.2 Chronic Dacryocystitis . . . 60 3.3.1.3 Neonatal Dacryocystitis . . . 60 3.3.2 Canaliculitis . . . 61 3.3.3 Tumors of the Lacrimal Sac . . . 61 3.4 Lacrimal System Dysfunction . . . 62 3.4.1 Keratoconjunctivitis Sicca . . . 62 Table of Contents Lang, Ophthalmology © 2000 Thieme All rights reserved. Usage subject to terms and conditions of license. VIII 3.4.2 Illacrimation . . . 64 3.5 Disorders of the Lacrimal Gland . . . 64 3.5.1 Acute Dacryoadenitis . . . 64 3.5.2 Chronic Dacryoadenitis . . . 65 3.5.3 Tumors of the Lacrimal Gland . . . 66 4 Conjunctiva . . . 67 (Gerhard K. Lang, Gabriele E. Lang) 4.1 Basic Knowledge . . . 67 4.2 Examination Methods . . . 68 4.3 Conjunctival Degeneration and Aging Changes . . . 69 4.3.1 Pinguecula . . . 69 4.3.2 Pterygium . . . 69 4.3.3 Pseudopterygium . . . 71 4.3.4 Subconjunctival Hemorrhage . . . 72 4.3.5 Calcareous Infiltration . . . 72 4.3.6 Conjunctival Xerosis . . . 72 4.4 Conjunctivitis . . . 74 4.4.1 General Notes on the Causes, Symptoms, and Diagnosis of Conjunctivitis . . . 74 4.4.2 Infectious Conjunctivitis . . . 82 4.4.2.1 Bacterial Conjunctivitis . . . 82 4.4.2.2 Chlamydial Conjunctivitis . . . 83 4.4.2.3 Viral Conjunctivitis . . . 93 4.4.2.4 Neonatal Conjunctivitis . . . 95 4.4.2.5 Parasitic and Mycotic Conjunctivitis . . . 98 4.4.3 Noninfectious Conjunctivitis . . . 98 4.5 Tumors . . . 104 4.5.1 Epibulbar Dermoid . . . 104 4.5.2 Conjunctival Hemangioma . . . 104 4.5.3 Epithelial Conjunctival Tumors . . . 105 4.5.3.1 Conjunctival Cysts . . . 105 4.5.3.2 Conjunctival Papilloma . . . 106 4.5.3.3 Conjunctival Carcinoma . . . 107 4.5.4 Melanocytic Conjunctival Tumors . . . 108 4.5.4.1 Conjunctival Nevus . . . 108 4.5.4.2 Conjunctival Melanosis . . . 108 4.5.4.3 Congenital Ocular Melanosis . . . 112 4.5.5 Conjunctival Lymphoma . . . 113 4.5.6 Kaposi’s Sarcoma . . . 113 4.6 Conjunctival Deposits . . . 114 Table of Contents Lang, Ophthalmology © 2000 Thieme All rights reserved. Usage subject to terms and conditions of license. IX 5 Cornea . . . 117 (Gerhard K. Lang) 5.1 Basic Knowledge . . . 117 5.2 Examination Methods . . . 120 5.2.1 Slit Lamp Examination . . . 120 5.2.2 Dye Examination of the Cornea . . . 120 5.2.3 Corneal Topography . . . 121 5.2.4 Determining Corneal Sensitivity . . . 121 5.2.5 Measuring the Density of the Corneal Epithelium . . . 121 5.2.6 Measuring the Diameter of the Cornea . . . 124 5.2.7 Corneal Pachymetry . . . 125 5.2.8 Confocal Corneal Microscopy . . . 125 5.3 Developmental Anomalies . . . 125 5.3.1 Protrusion Anomalies . . . 125 5.3.1.1 Keratoconus . . . 125 5.3.1.2 Keratoglobus . . . 127 5.3.2 Corneal Size Anomalies (Microcornea and Megalocornea) . . . 127 5.4 Infectious Keratitis . . . 127 5.4.1 Protective Mechanisms of the Cornea . . . 127 5.4.2 Corneal Infections: Predisposing Factors, Pathogens, and Pathogenesis . . . 128 5.4.3 General Notes on Diagnosing Infectious Forms of Keratitis . . . 130 5.4.4 Bacterial Keratitis . . . 130 5.4.5 Viral Keratitis . . . 132 5.4.5.1 Herpes Simplex Keratitis . . . 132 5.4.5.2 Herpes Zoster Keratitis . . . 134 5.4.6 Mycotic Keratitis . . . 134 5.4.7 Acanthamoeba Keratitis . . . 136 5.5 Noninfectious Keratitis and Keratopathy . . . 137 5.5.1 Superficial Punctate Keratitis . . . 138 5.5.2 Exposure Keratitis . . . 140 5.5.3 Neuroparalytic Keratitis . . . 141 5.5.4 Problems with Contact Lenses . . . 141 5.5.5 Bullous Keratopathy . . . 143 5.6 Corneal Deposits, Degenerations, and Dystrophies . . . 145 5.6.1 Corneal Deposits . . . 145 5.6.1.1 Arcus Senilis . . . 145 5.6.1.2 Corneal Verticillata . . . 145 5.6.1.3 Argyrosis and Chrysiasis . . . 146 5.6.1.4 Iron Lines . . . 146 5.6.1.5 Kayser-Fleischer Ring . . . 146 Table of Contents Lang, Ophthalmology © 2000 Thieme All rights reserved. Usage subject to terms and conditions of license. X 5.6.2 Corneal Degeneration . . . 146 5.6.2.1 Calcific Band Keratopathy . . . 146 5.6.2.2 Peripheral Furrow Keratitis . . . 147 5.6.3 Corneal Dystrophies . . . 148 5.7 Corneal Surgery . . . 150 5.7.1 Curative Corneal Procedures . . . 152 5.7.1.1 Penetrating Keratoplasty (Fig. 5.18a) . . . 152 5.7.1.2 Lamellar Keratoplasty (Fig. 5.18b) . . . 153 5.7.1.3 Phototherapeutic Keratectomy (Fig. 5.18c) . . . 154 5.7.2 Refractive Corneal Procedures . . . 155 5.7.2.1 Photorefractive Keratectomy (Fig. 5.18d) . . . 155 5.7.2.2 Radial Keratotomy (Fig. 5.18e) . . . 155 5.7.2.3 Photorefractive Keratectomy Correction of Astigmatism . . . 156 5.7.2.4 Holmium Laser Correction of Hyperopia . . . 156 5.7.2.5 Epikeratophakic Keratoplasty (Epikeratophakia) . . . 156 5.7.2.6 Excimer Laser In Situ Keratomileusis (LASIK) . . . 156 6 Sclera . . . 157 (Gerhard K. Lang) 6.1 Basic Knowledge . . . 157 6.2 Examination Methods . . . 157 6.3 Color Changes . . . 157 6.4 Staphyloma and Ectasia . . . 158 6.5 Trauma . . . 158 6.6 Inflammations . . . 158 6.6.1 Episcleritis . . . 159 6.6.2 Scleritis . . . 161 7 Lens . . . 165 (Gerhard K. Lang) 7.1 Basic Knowledge . . . 165 7.2 Examination Methods . . . 168 7.3 Developmental Anomalies of the Lens . . . 169 7.4 Cataract . . . 170 7.4.1 Acquired Cataract . . . 173 7.4.1.1 Senile Cataract . . . 173 7.4.2 Cataract in Systemic Disease . . . 179 7.4.3 Complicated Cataracts . . . 180 7.4.4 Cataract after Intraocular Surgery . . . 180 Table of Contents Lang, Ophthalmology © 2000 Thieme All rights reserved. Usage subject to terms and conditions of license. XI 7.4.5 Traumatic Cataract . . . 180 7.4.6 Toxic Cataract . . . 182 7.4.7 Congenital Cataract . . . 182 7.4.7.1 Hereditary Congenital Cataracts . . . 183 7.4.7.2 Cataract from Transplacental Infection in the First Trimester of Pregnancy . . . 185 7.4.8 Treatment of Cataracts . . . 185 7.4.8.1 Medical Treatment . . . 185 7.4.8.2 Surgical Treatment . . . 185 7.4.8.3 Secondary Cataract . . . 192 7.4.8.4 Special Considerations in Cataract Surgery in Children . . . 192 7.5 Lens Dislocation . . . 195 8 Uveal Tract (Vascular Pigmented Layer) . . . 199 (Gabriele E. Lang, Gerhard K. Lang) 8.1 Basic Knowledge . . . 199 8.1.1 Iris . . . 199 8.1.2 Ciliary Body . . . 201 8.1.3 Choroid . . . 201 8.2 Examination Methods . . . 201 8.3 Developmental Anomalies . . . 202 8.3.1 Aniridia . . . 202 8.3.2 Coloboma . . . 203 8.4 Pigmentation Anomalies . . . 206 8.4.1 Heterochromia . . . 206 8.4.2 Albinism . . . 206 8.5 Inflammation . . . 208 8.5.1 Acute Iritis and Iridocyclitis . . . 208 8.5.2 Chronic Iritis and Iridocyclitis . . . 212 8.5.3 Choroiditis . . . 213 8.5.4 Sympathetic Ophthalmia . . . 214 8.6 Neovascularization in the Iris: Rubeosis Iridis . . . 215 8.7 Tumors . . . 216 8.7.1 Malignant Tumors (Uveal Melanoma) . . . 216 8.7.2 Benign Choroidal Tumors . . . 217 Table of Contents Lang, Ophthalmology © 2000 Thieme All rights reserved. Usage subject to terms and conditions of license. XII 9 Pupil . . . 219 (Oskar Gareis, Gerhard K. Lang) 9.1 Basic Knowledge . . . 219 9.2 Examination Methods . . . 221 9.2.1 Testing the Light Reflex (Table 9.1) . . . 221 9.2.2 Evaluating the Near Reflex . . . 223 9.3 Influence of Pharmacologic Agents on the Pupil (Table 9.2) . . . 224 9.4 Pupillary Motor Dysfunction . . . 226 9.4.1 Isocoria with Normal Pupil Size . . . 227 9.4.2 Anisocoria with Dilated Pupil in the Affected Eye . . . 228 9.4.3 Anisocoria with a Constricted Pupil in the Affected Eye . . . 229 9.4.4 Isocoria with Constricted Pupils . . . 230 9.3.5 Isocoria with Dilated Pupils . . . 231 10 Glaucoma . . . 233 (Gerhard K. Lang) 10.1 Basic Knowledge . . . 233 10.2 Examination Methods . . . 238 10.2.1 Oblique Illumination of the Anterior Chamber . . . 238 10.2.2 Slit-Lamp Examination . . . 238 10.2.3 Gonioscopy . . . 238 10.2.4 Measuring Intraocular Pressure . . . 240 10.2.5 Optic Disk Ophthalmoscopy . . . 244 10.2.6 Visual Field Testing . . . 246 10.2.7 Examination of the Retinal Nerve Fiber Layer . . . 250 10.3 Primary Glaucoma . . . 251 10.3.1 Primary Open Angle Glaucoma . . . 251 10.3.2 Primary Angle Closure Glaucoma . . . 265 10.4 Secondary Glaucomas . . . 270 10.4.1 Secondary Open Angle Glaucoma . . . 271 10.4.2 Secondary Angle Closure Glaucoma . . . 271 10.5 Childhood Glaucomas . . . 273 11 Vitreous Body . . . 279 (Christoph W. Spraul, Gerhard K. Lang) 11.1 Basic Knowledge . . . 279 11.2 Examination Methods . . . 281 11.3 Aging Changes . . . 282 Table of Contents Lang, Ophthalmology © 2000 Thieme All rights reserved. Usage subject to terms and conditions of license. XIII 11.3.1 Synchysis . . . 282 11.3.2 Vitreous Detachment . . . 282 11.4 Abnormal Changes in the Vitreous Body . . . 284 11.4.1 Persistent Fetal Vasculature (Developmental Anomalies) . . . 284 11.4.1.1 Mittendorf’s Dot . . . 284 11.4.1.2 Bergmeister’s Papilla . . . 285 11.4.1.3 Persistent Hyaloid Artery . . . 285 11.4.1.4 Persistent Hyperplastic Primary Vitreous (PHPV) . . . 285 11.4.2 Abnormal Opacities of the Vitreous Body . . . 287 11.4.2.1 Asteroid Hyalosis . . . 287 11.4.2.2 Synchysis Scintillans . . . 287 11.4.2.3 Vitreous Amyloidosis . . . 287 11.4.3 Vitreous Hemorrhage . . . 287 11.4.4 Vitritis and Endophthalmitis . . . 290 11.4.5 Vitreoretinal Dystrophies . . . 293 11.4.5.1 Juvenile Retinoschisis . . . 293 11.4.5.2 Wagner’s Disease . . . 293 11.5 The Role of the Vitreous Body in Various Ocular Changes and Following Cataract Surgery . . . 293 11.5.1 Retinal Detachment . . . 293 11.5.2 Retinal Vascular Proliferation . . . 293 11.5.3 Cataract Surgery . . . 294 11.6 Surgical Treatment: Vitrectomy . . . 294 12 Retina . . . 299 (Gabriele E. Lang, Gerhard K. Lang) 12.1 Basic Knowledge . . . 299 12.2 Examination Methods . . . 304 12.2.1 Examination of the Fundus . . . 304 12.2.2 Normal and Abnormal Fundus Findings in General . . . 308 12.2.3 Color Vision . . . 311 12.2.4 Electrophysiologic Examination Methods (electroretinogram, electrooculogram, and visual evoked potentials; see Fig. 12.2a) . . . 312 12.3 Vascular Disorders . . . 314 12.3.1 Diabetic Retinopathy . . . 314 12.3.2 Retinal Vein Occlusion . . . 318 12.3.3 Retinal Arterial Occlusion . . . 320 12.3.4 Hypertensive Retinopathy and Sclerotic Changes . . . 323 12.3.5 Coats’ Disease . . . 325 12.3.6 Retinopathy of Prematurity . . . 326 Table of Contents Lang, Ophthalmology © 2000 Thieme All rights reserved. Usage subject to terms and conditions of license. XIV 12.4 Degenerative Retinal Disorders . . . 328 12.4.1 Retinal Detachment . . . 328 12.4.2 Degenerative Retinoschisis . . . 333 12.4.3 Peripheral Retinal Degenerations . . . 334 12.4.4 Central Serous Chorioretinopathy . . . 335 12.4.5 Age-Related Macular Degeneration . . . 337 12.4.6 Degenerative Myopia . . . 339 12.5 Retinal Dystrophies . . . 340 12.5.1 Macular Dystrophies . . . 340 12.5.1.1 Stargardt’s Disease . . . 340 12.5.1.2 Best’s Vitelliform Dystrophy . . . 341 12.5.2 Retinitis Pigmentosa . . . 343 12.6 Toxic Retinopathy . . . 345 12.7 Retinal Inflammatory Disease . . . 346 12.7.1 Retinal Vasculitis . . . 346 12.7.2 Posterior Uveitis Due to Toxoplasmosis . . . 348 12.7.3 AIDS-Related Retinal Disorders . . . 349 12.7.4 Viral Retinitis . . . 351 12.7.5 Retinitis in Lyme Disease . . . 351 12.7.6 Parasitic Retinal Disorders . . . 352 12.8 Retinal Tumors and Hamartomas . . . 353 12.8.1 Retinoblastoma . . . 353 12.8.2 Astrocytoma . . . 355 12.8.3 Hemangiomas . . . 356 13 Optic Nerve . . . 359 (Oskar Gareis, Gerhard K. Lang) 13.1 Basic Knowledge . . . 359 13.1.1 Intraocular Portion of the Optic Nerve . . . 360 13.1.2 The Intraorbital and Intracranial Portion of the Optic Nerve . . . 361 13.2 Examination Methods . . . 362 13.3 Disorders that Obscure the Margin of the Optic Disc . . . 363 13.3.1 Congenital Disorders that Obscure the Margin of the Optic Disc . . . 363 13.3.1.1 Oblique Entry of the Optic Nerve . . . 363 13.3.1.2 Tilted Disc . . . 364 13.3.1.3 Pseudopapilledema . . . 364 13.3.1.4 Myelinated Nerve Fibers . . . 365 13.3.1.5 Bergmeister’s Papilla . . . 366 13.3.1.6 Optic Disc Drusen . . . 366 13.3.2 Acquired Disorders that Obscure the Margin of the Optic Disc . . . 367 Table of Contents Lang, Ophthalmology © 2000 Thieme All rights reserved. Usage subject to terms and conditions of license. XV 13.3.2.1 Papilledema . . . 368 13.3.2.2 Optic Neuritis . . . 370 13.3.2.3 Anterior Ischemic Optic Neuropathy (AION) . . . 374 13.3.2.4 Infiltrative Optic Disc Edema . . . 379 13.4 Disorders in which the Margin of the Optic Disc isWell Defined . . . 380 13.4.1 Atrophy of the Optic Nerve . . . 380 13.4.2 Optic Nerve Pits . . . 383 13.4.3 Optic Disc Coloboma (Morning Glory Disc) . . . 385 13.5 Tumors . . . 385 13.5.1 Intraocular Optic Nerve Tumors . . . 385 13.5.2 Retrobulbar Optic Nerve Tumors . . . 387 14 Visual Pathway . . . 389 (Oskar Gareis, Gerhard K. Lang) 14.1 Basic Knowledge . . . 389 14.2 Examination Methods . . . 391 14.3 Disorders of the Visual Pathway . . . 394 14.3.1 Prechiasmal Lesions . . . 394 14.3.2 Chiasmal Lesions . . . 396 14.3.3 Retrochiasmal Lesions . . . 400 15 Orbital Cavity . . . 403 (Christoph W. Spraul, Gerhard K. Lang) 15.1 Basic Knowledge . . . 403 15.2 Examination Methods . . . 405 15.3 Developmental Anomalies . . . 409 15.3.1 Craniofacial Dysplasia . . . 409 15.3.1.1 Craniostenosis . . . 409 15.3.2 Mandibulofacial Dysplasia . . . 410 15.3.2.1 Oculoauriculovertebral Dysplasia . . . 410 15.3.2.2 Mandibulofacial Dysostosis . . . 410 15.3.2.3 Oculomandibular Dysostosis . . . 410 15.3.2.4 Rubinstein–Taybi Syndrome . . . 410 15.3.3 Meningoencephalocele . . . 410 15.3.4 Osteopathies . . . 411 15.4 Orbital Involvement in Autoimmune Disorders: Graves’ Disease . . . 411 15.5 Orbital Inflammation . . . 413 15.5.1 Orbital Cellulitis . . . 414 Table of Contents Lang, Ophthalmology © 2000 Thieme All rights reserved. Usage subject to terms and conditions of license. XVI 15.5.2 Cavernous Sinus Thrombosis . . . 415 15.5.3 Orbital Pseudotumor . . . 416 15.5.4 Myositis . . . 416 15.5.5 Orbital Periostitis . . . 417 15.5.6 Mucocele . . . 417 15.5.7 Mycoses (Mucormycosis and Aspergillomycosis) . . . 417 15.6 Vascular Disorders . . . 418 15.6.1 Pulsating Exophthalmos . . . 418 15.6.2 Intermittent Exophthalmos . . . 419 15.6.3 Orbital Hematoma . . . 419 15.7 Tumors . . . 420 15.7.1 Orbital Tumors . . . 420 15.7.1.1 Hemangioma . . . 420 15.7.1.2 Dermoid and Epidermoid Cyst . . . 420 15.7.1.3 Neurinoma and Neurofibroma . . . 420 15.7.1.4 Meningioma . . . 420 15.7.1.5 Histiocytosis X . . . 421 15.7.1.6 Leukemic Infiltrations . . . 421 15.7.1.7 Lymphoma . . . 421 15.7.1.8 Rhabdomyosarcoma . . . 421 15.7.2 Metastases . . . 421 15.7.3 Optic Nerve Glioma . . . 422 15.8 Orbital Surgery . . . 422 16 Optics and Refractive Errors . . . 423 (Christoph W. Spraul, Gerhard K. Lang) 16.1 Basic Knowledge . . . 423 16.1.1 Uncorrected and Corrected Visual Acuity . . . 423 16.1.2 Refraction: Emmetropia and Ametropia . . . 423 16.1.3 Accommodation . . . 425 16.1.4 Adaptation to Differences in Light Intensity . . . 428 16.2 Examination Methods . . . 429 16.2.1 Refraction Testing . . . 429 16.2.2. Testing the Potential Resolving Power of the Retina in the Presence of Opacified Optic Media . . . 431 16.3 Refractive Anomalies (Table 16.2) . . . 432 16.3.1 Myopia (Shortsightedness) . . . 432 16.3.2 Hyperopia (Farsightedness) . . . 436 16.3.3 Astigmatism . . . 440 16.3.4 Anisometropia . . . 444 16.4 Impaired Accommodation . . . 445 16.4.1 Accommodation Spasm . . . 445 Table of Contents Lang, Ophthalmology © 2000 Thieme All rights reserved. Usage subject to terms and conditions of license. XVII 16.4.2 Accommodation Palsy . . . 446 16.5 Correction of Refractive Errors . . . 447 16.5.1 Eyeglass Lenses . . . 447 16.5.2 Contact Lenses . . . 451 16.5.2.1 Advantages and Characteristics of Contact Lenses . . . 451 16.5.3 Prisms . . . 455 16.5.4 Magnifying Vision Aids . . . 455 16.5.5 Aberrations of Lenses and Eyeglasses . . . 456 17 Ocular Motility and Strabismus . . . 459 (Doris Recker, Josef Amann, Gerhard K. Lang) 17.1 Basic Knowledge . . . 459 17.2 Concomitant Strabismus . . . 465 17.2.1 Forms of Concomitant Strabismus . . . 467 17.2.1.1 Esotropia . . . 467 17.2.1.2 Abnormal Accommodative Convergence/Accommodation Ratio . . . 470 17.2.1.3 Exotropia . . . 471 17.2.1.4 Vertical Deviations (Hypertropia and Hypotropia) . . . 471 17.2.2 Diagnosis of Concomitant Strabismus . . . 471 17.2.2.1 Evaluating Ocular Alignment with a Focused Light . . . 471 17.2.2.2 Diagnosis of Infantile Strabismic Amblyopia (Preferential Looking Test) . . . 472 17.2.2.3 Diagnosis of Unilateral and Alternating Strabismus (Unilateral Cover Test) . . . 473 17.2.2.4 Measuring the Angle of Deviation . . . 474 17.2.2.5 Determining the Type of Fixation . . . 476 17.2.2.6 Testing Binocular Vision . . . 476 17.2.3 Therapy of Concomitant Strabismus . . . 477 17.2.3.1 Eyeglass Prescription . . . 477 17.2.3.2 Treatment and Avoidance of Strabismic Amblyopia . . . 477 17.2.3.3 Surgery . . . 479 17.3 Heterophoria . . . 480 17.4 Pseudostrabismus . . . 481 17.5 Ophthalmoplegia and Paralytic Strabismus . . . 481 17.6 Nystagmus . . . 494 Table of Contents Lang, Ophthalmology © 2000 Thieme All rights reserved. Usage subject to terms and conditions of license. XVIII 18 Ocular Trauma . . . 497 (Gerhard K. Lang) 18.1 Examination Methods . . . 497 18.2 Classification of Ocular Injuries by Mechanism of Injury . . . 498 18.3 Mechanical Injuries . . . 498 18.3.1 Eyelid Injury . . . 498 18.3.2 Injuries to the Lacrimal System . . . 499 18.3.3 Conjunctival Laceration . . . 499 18.3.4 Corneal and Conjunctival Foreign Bodies . . . 503 18.3.5 Corneal Erosion . . . 505 18.3.6 Blunt Ocular Trauma (Ocular Contusion) . . . 506 18.3.7 Blowout Fracture . . . 507 18.3.8 Open-Globe Injuries . . . 514 18.3.9 Impalement Injuries of the Orbit . . . 515 18.4 Chemical Injuries . . . 517 18.5 Injuries Due to Physical Agents . . . 523 18.5.1 Ultraviolet Keratoconjunctivitis . . . 523 18.5.2 Burns . . . 523 18.5.3 Radiation Injuries (Ionizing Radiation) . . . 524 18.6 Indirect Ocular Trauma: Purtscher’s Retinopathy . . . 525 19 Cardinal Symptoms . . . 527 (Gerhard K. Lang) Index . . . 563 Table of Contents Lang,