Ординатура / Офтальмология / Английские материалы / Primary Care Ophthalmology_Palay, Krachmer_2005
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Syndromes Affecting Vision |
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•Laser refractive surgery in children with a unilateral high degree of myopia has been performed and is under study but at present is not widely recommended for children younger than 18 years of age.
Inherited Retinal and Corneal Degenerations
Many retinal degenerations such as retinitis pigmentosa are hereditary. Decreased night vision often is an early symptom. Photophobia can occur during childhood in cases of inherited corneal dystrophies and some cone retinal dystrophies. Congenitally deaf children have an increased risk of retinitis pigmentosa (the combination of this disorder plus deafness constitutes Usher syndrome) and require close ophthalmologic follow-up. Any child with a family member who has significant early-onset vision problems requires a baseline examination early in life and again if symptoms occur. DNA blood tests are now available for some inherited eye disorders.
Syndromes Affecting Vision
Approximately 25% of the U.S. population is nearsighted (myopic), and although myopia begins in childhood, it usually is of low to moderate degree and increases slowly throughout adolescence. If high myopia or rapidly progressive myopia is present before 6 years of age, an underlying syndrome should be sought. Homocystinuria, Marfan syndrome, Weill-Marchesani syndrome, and sulfite oxidase deficiency are associated with lens subluxation, which causes high myopia. These disorders can be life-threatening. Stickler syndrome is a disorder of autosomal dominant inheritance that includes cleft palate, early arthritis, partial deafness, and high myopia. High hyperopia and astigmatism may be associated with albinism. Retinal dystrophies may be associated with many different metabolic and genetic syndromes with such associated findings as developmental delay, extra toes and fingers, and deafness, among others. Any child with a very high refractive error, especially myopia, or decreased vision not correctable by spectacles, should undergo a complete workup by a pediatric ophthalmologist and by a geneticist if indicated.
CHAPTER 14
Orbital Disease
TED H. WOJNO
Related Anatomy
The bony orbit is a four-sided pyramid with the apex pointed posteriorly (Fig. 14–1). The medial orbital wall is composed mainly of the ethmoid bone. The lateral wall is composed of the zygomatic bone anteriorly and the greater wing of the sphenoid bone posteriorly. The superior wall is composed of the frontal bone, whereas the inferior wall is formed by the maxillary and zygomatic bones. The optic foramen transmits the optic nerve and the ophthalmic artery. The superior orbital fissure transmits the third, the fourth, the ophthalmic division of the fifth, and the sixth cranial nerves.
The four rectus muscles are involved in horizontal and vertical movements of the globe (Fig. 14–2). The superior and inferior oblique muscles are involved in the globe’s torsional movements, and the orbital fat cushions and supports the globe. The pink lacrimal gland is located just under the superolateral orbital rim. The clinician can easily visualize this structure, which is responsible for reflex tearing, by retracting the upper lid superolaterally and having the patient look inferonasally (Fig. 14–3). The lacrimal drainage system begins with the puncta and canaliculi, which join to enter the lacrimal sac (Fig. 14–4). The sac empties into the nasolacrimal duct, which passes through the medial wall of the maxillary sinus and empties into the nose under the inferior turbinate.
Preseptal Cellulitis
For preseptal cellulitis in children, see Chapter 13.
Symptoms
•Warm, erythematous, tender swelling of the lids may extend over the nasal bridge to the opposite side.
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276 CHAPTER 14 • Orbital Disease
Orbital plate |
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Superior |
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of greater wing |
Lesser wing |
orbital |
Frontal |
of sphenoid |
of sphenoid |
fissure |
bone |
Body of sphenoid
Optic foramen
Ethmoid
Lacrimal bone
Palatine bone
Orbital plate 
of maxilla
Infraorbital groove
Inferior orbital fissure
Zygomatic bone
FIGURE 14–1 Anterior view of the orbit.
Signs
•A low-grade fever and elevated white blood cell count are usual findings.
•Vision, pupillary reflexes, and extraocular movements are normal.
•Blood culture results are negative unless the organism is Haemophilus influenzae or
Streptococcus pneumoniae.
Etiology
•An upper respiratory tract infection or sinusitis can result in the disorder. The most common causative organisms in adults are Streptococcus species, Staphylococcus aureus, and mixed flora.
•Lid trauma (blunt or perforating) can lead to preseptal cellulitis. The most common causative organisms are Streptococcus pyogenes, S. aureus, and fungus (if organic material was involved).
•The disorder can result from superficial lid infections such as a stye (hordeolum) or impetigo.
•Conjunctivitis can cause the disorder.
Preseptal Cellulitis |
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Superior rectus muscle (3rd nerve) Inferior oblique muscle (3rd nerve) Inferior rectus muscle (3rd nerve)
Medial rectus muscle (3rd nerve)
Levator palpebrae muscle (3rd nerve)
Superior oblique muscle (4th nerve)
Lateral rectus muscle (6th nerve)
FIGURE 14–2 The extraocular muscles.
FIGURE 14–3 The normal lacrimal gland (1).
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278 CHAPTER 14 • Orbital Disease
Upper canaliculus
Upper punctum
FIGURE 14–4 The nasolacrimal excretory system.
Lower |
Nasolacrimal sac |
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punctum |
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Lower |
Nasolacrimal duct |
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canaliculus |
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Common |
Inferior turbinate |
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canaliculus |
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Valve of Hasner |
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•Dacryocystitis can lead to the disorder.
•In rare cases, septicemia results in the disorder.
Differential Diagnosis
Considerations in the differential diagnosis include the following:
•Orbital cellulitis
•Orbital pseudotumor
•Carotid artery–cavernous sinus fistula
Workup
•A CBC is performed.
•Culture of material obtained from an open wound, purulent nasal drainage, conjunctival discharge, or any weeping vesicles is performed.
•Computed tomography (CT) scan of orbits and sinuses is performed if indicated.
•Blood cultures are performed if H. influenzae or S. pneumoniae infection is suspected.
Treatment
•In cases of mild to moderate preseptal cellulitis without localized abscess, an oral broad-spectrum antibiotic (e.g., amoxicillin/clavulanate [Augmentin] 500 to 875 mg two times a day) is administered. If the patient is allergic to penicillin, oral erythromycin (250 to 500 mg four times a day) is given.
•In cases of severe preseptal cellulitis, an intravenous broad-spectrum antibiotic (e.g., cefuroxime [Zinacef] 750 mg to 1.5 g three times a day) is administered. If the
Orbital Cellulitis and Abscess |
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patient is allergic to penicillin, intravenous clindamycin (300 mg four times a day) and intravenous gentamicin (1 mg/kg three times a day) are administered.
•Note: Antibiotic dosages should be adjusted in the presence of renal impairment. Peak and trough levels of gentamicin are used to adjust dosage. Blood urea nitrogen (BUN) and creatinine levels are followed closely.
•In cases of localized abscess formation, an oral or intravenous broad-spectrum antibiotic is administered, depending on the severity of the abscess. Incision and drainage with or without a placement of a drain may be performed, depending on the severity of the abscess.
•For lesions with extensive crusting, after incision and drainage, or in cases of penetrating injury, a topical broad-spectrum ophthalmic ointment such as polymyxin B/bacitracin (Polysporin) is used.
Follow-up
• The focus of follow-up is on preventing the development of orbital cellulitis.
Orbital Cellulitis and Abscess
For orbital cellulitis in children, see Chapter 13.
Symptoms
•The symptoms are the same as those for preseptal cellulitis. Orbital involvement can lead to vision loss and double vision.
Signs
•A low-grade fever and elevated white blood cell count are usual findings.
•Proptosis, restricted motility, sluggish pupillary reflex, and decreased vision are noted (Fig. 14–5).
FIGURE 14–5 Orbital cellulitis resulting from ethmoid sinusitis.
280 CHAPTER 14 • Orbital Disease
FIGURE 14–6 An axial computed tomography scan of the head obtained in the patient in Figure 14–5 shows diffuse infiltration of the left orbital structures.
Workup
•Workup is the same as that for cases of preseptal cellulitis.
•A funduscopic examination may reveal retinal hemorrhages, venous congestion, and disc edema.
•A CT scan displays diffuse infiltration of orbital fat that may progress to abscess formation (Fig. 14–6).
•Blood culture results usually are negative.
Etiology
•Underlying causes are the same as those for preseptal cellulitis.
•Surgical procedures that violate the orbital septum such as strabismus, retinal detachment repair, and orbital surgery can lead to the disorder.
Differential Diagnosis
•Considerations in the differential diagnosis are the same as those for preseptal cellulitis.
Treatment
•An intravenous broad-spectrum antibiotic (e.g., cefuroxime [Zinacef] 750 mg to 1.5 g three times a day) is used. If the patient is allergic to penicillin, intravenous clindamycin (300 mg four times a day) and intravenous gentamicin (1 mg/kg three times a day) are used.
•Note: Antibiotic dosages should be adjusted in the presence of renal impairment. Peak and trough levels of gentamicin are used to adjust dosage. Blood urea nitrogen (BUN) and creatinine levels are followed closely.
•Surgical drainage is needed for a large abscess or small abscess that does not resolve after 2 or 3 days of intravenous antibiotic therapy.
•Sinus drainage is performed if appropriate.
Dacryocystitis 281
Follow-up
•The focus of follow-up is on preventing development of cavernous sinus thrombosis.
Nasolacrimal Duct Obstruction
Symptoms and Signs
• Tearing occurs.
Etiology and Associated Factors and Diseases
•Previous nasal or sinus disease, surgery, or trauma can lead to stenosis of the nasolacrimal duct.
•The disorder can have an idiopathic origin.
•In rare cases, a tumor also may be present.
Differential Diagnosis
• Tearing secondary to ocular irritation should be ruled out or confirmed.
Workup
•Probing and irrigation of the nasolacrimal system are performed to confirm the presence of an obstruction.
Treatment
•If the patient and the physician feel that the symptoms warrant intervention, a surgical fistula is created by connecting the lacrimal sac to the nasal mucosa, thus bypassing the obstructed nasolacrimal duct (dacryocystorhinostomy).
Dacryocystitis
Symptoms
•Tearing, pain, and mucopurulent drainage occur in dacryocystitis (infection of the lacrimal sac).
Signs
•Tearing, swollen lacrimal sac, and mucopurulent drainage are evident (Fig. 14–7).
•In rare cases, preseptal cellulitis occurs.
Etiology
• Nasolacrimal duct obstruction can lead to infection of the lacrimal sac.
282 CHAPTER 14 • Orbital Disease
FIGURE 14–7 Acute dacryocystitis. This acute infection involves erythema and enlargement lateral to the nasal bridge. Mucopurulent conjunctivitis is also present.
Differential Diagnosis
• An ethmoid mucocele should be ruled out or confirmed.
Workup
•Digital pressure over the lacrimal sac may cause reflux of the mucopurulent material.
Treatment
•In cases of acute dacryocystitis, an oral, broad-spectrum antibiotic (e.g., amoxicillin/clavulanate [Augmentin] 500 to 875 mg two times a day) is administered. If the patient is allergic to penicillin, oral erythromycin (250 to 500 mg 4 times a day) is used.
•Incision and drainage are appropriate interventions if a large abscess has formed.
•Dacryocystorhinostomy or dacryocystectomy is performed when the infection is quiescent.
•In cases of chronic dacryocystitis, dacryocystorhinostomy or dacryocystectomy is performed.
Dacryoadenitis
Symptoms
•Lateral lid swelling, pain, and tearing are features of dacryoadenitis (inflammation of the lacrimal gland).
Signs
•The lacrimal gland is swollen, tender, and erythematous (Fig. 14–8).
•Inferonasal globe displacement occurs.
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FIGURE 14–8 Acute viral dacryoadenitis. The superior temporal lid is erythematous, and the lid margin is S-shaped as a result of the underlying enlargement of the lacrimal gland.
Etiology
•Commonly, the inflammation is idiopathic.
•Less common inflammations include sarcoidosis, vasculitis, and Sjögren syndrome.
•Uncommonly, bacterial and viral infections (e.g., mononucleosis, mumps, herpes zoster) can lead to the disorder.
Differential Diagnosis
• Tumor of lacrimal gland should be ruled out or confirmed.
Workup
•Signs of bacterial or viral infection are sought.
•Signs of other inflammatory disorders are sought.
•A CT scan or an MRI study of the orbits is performed.
•A biopsy of the lacrimal gland is undertaken if indicated.
Treatment
•In cases of idiopathic inflammation, oral corticosteroids are administered.
•In cases of a specific inflammation the underlying disorder is treated.
•In cases of infectious agents the following apply:
Oral, broad-spectrum antibiotics (e.g., amoxicillin/clavulanate [Augmentin] 500 to 875 mg two times a day) is used for bacterial infection. If the patient is allergic to penicillin, oral erythromycin (250 to 500 mg 4 times a day) is administered.
In cases of viral infection, the underlying disorder is treated.
Follow-up
•A biopsy of the lacrimal gland is performed if the condition fails to resolve with appropriate therapy.