Ординатура / Офтальмология / Английские материалы / Primary Care Ophthalmology_Palay, Krachmer_2005
.pdf
140 CHAPTER 9 • Uveitis
Iris + Ciliary body |
+ |
Choroid = Uveal tract |
FIGURE 9–1 The uveal tract, composed of the iris, ciliary body, and choroid.
in the posterior segment, often is difficult. Classification of a uveitis as anterior or posterior may be difficult, because both segments may be involved. A severe anterior uveitis may result in anterior vitreous changes, whereas a vitritis may manifest with signs in the anterior chamber. When both segments of the uveal tract are definitely involved, the condition is called panuveitis. The term endophthalmitis is reserved for cases in which the inflammation is predominantly centered within the vitreous—a special type of posterior uveitis remarkable for its severity, necessitating prompt diagnostic workup and treatment (see Chapter 10).
Anterior Uveitis
Symptoms
•Redness, photophobia, and pain are characteristic.
•Vision is normal or decreased.
•The onset of symptoms is acute or insidious.
•Possible nonocular symptoms (e.g., back pain, joint stiffness, dysuria) are caused by various systemic disorders associated with uveitis.
Anterior Uveitis |
141 |
|
|
Signs
•The disorder is unilateral or bilateral.
•Conjunctival injection is seen, primarily surrounding the cornea (ciliary injection) (Fig. 9–2).
•Deposits on the posterior surface of the cornea (keratic precipitates) vary in size and appearance (fine and whitish precipitates in nongranulomatous uveitis and large, grayish, “mutton-fat” precipitates in granulomatous uveitis) (Figs. 9–3 and 9–4).
•Floating inflammatory cells and protein (seen as “flare”) in the anterior chamber are detectable only with the aid of a slit lamp biomicroscope. If severe enough, these inflammatory cells can layer in the anterior chamber (hypopyon) (Fig. 9–5).
•Adhesions of the iris to the front surface of the lens (posterior synechiae) may form, which may result in a small or irregularly shaped pupil (Fig. 9–6A). A 360-degree distribution of posterior synechiae may inhibit normal aqueous flow to create iris bombé and angle-closure glaucoma (Fig. 9–6B).
•A constricted pupil is evident, even without posterior synechiae.
1
FIGURE 9–2 Marked ciliary injection (1) in addition to generalized conjunctival injection (2) in this eye of a patient with
ankylosing spondylitis.
2
FIGURE 9–3 Fine keratic precipitates (1) with a nongranulomatous anterior uveitis.
1
142 CHAPTER 9 • Uveitis
1
FIGURE 9–4 “Mutton-fat” keratic precipitates (1) are diffusely scattered on the posterior surface of the cornea.
FIGURE 9–5 Accumulation of inflammatory cells forming a hypopyon in the anterior chamber.
•Nodules of inflammatory cells are found on the iris surface. These lesions are termed Koeppe nodules if they are located at the pupillary margin and Busacca nodules if located on the remainder of the iris surface (Fig. 9–7).
Etiology
•Most cases have an idiopathic origin.
•Many local and systemic associations have been identified, as outlined in Box 9–1.
Associated Factors and Diseases
•Cataract and glaucoma are associated with anterior uveitis.
•Low intraocular pressure (hypotony) may be present.
Anterior Uveitis |
143 |
|
|
A B
FIGURE 9–6 A, Posterior synechiae causing iris pigment deposition on the anterior lens surface and an irregularly shaped pupil. B, Posterior synechiae in a 360-degree distribution inducing miosis and iris bombé, which may lead to pupillary block glaucoma.
FIGURE 9–7 Koeppe (1) and Busacca (2) nodules of sarcoid uveitis.
1
2
144 CHAPTER 9 • Uveitis
BOX 9–1 Classification of Anterior Uveitis
Autoimmune disorders
•HLA-B27 positive anterior uveitis
•Ankylosing spondylitis
•Reiter syndrome
•Inflammatory bowel disease (ulcerative colitis and Crohn’s disease)
•Psoriatic arthritis
•Juvenile rheumatoid arthritis
Infections
•Syphilis
•Tuberculosis
•Lyme disease
•Herpes simplex
•Herpes zoster
Malignancies*
•Lymphoma
•Leukemia
Other conditions
•Idiopathic disease
•Trauma
•Postoperative complication
•Sarcoidosis
•Behçet syndrome
*Noninflammatory conditions in which the clinical findings can mimic those with an anterior uveitis.
•Elevated intraocular pressure may be associated with pupillary block glaucoma, toxoplasmosis, and infections due to herpes simplex virus and herpes zoster virus.
Differential Diagnosis
Considerations in the differential diagnosis include the following:
•Conjunctivitis (injected conjunctiva but no cells or flare in the anterior chamber)
•Sclerouveitis (uveitis secondary to an inflammation of the sclera)
•Intraocular malignancy (e.g., leukemia)
Workup
•A careful history and complete ocular examination are necessary. A history of ocular trauma incurred 2 to 3 days before presentation may facilitate the diagnosis of traumatic iritis.
Posterior Uveitis |
145 |
|
|
•The general physical examination is directed at possible systemic findings with the various conditions associated with an anterior uveitis.
•For patients with unilateral, nongranulomatous, first-episode disease and unremarkable history and physical findings, no systemic workup is needed.
•For patients with bilateral, granulomatous, recurrent disease and unremarkable history and physical findings, the followings steps are taken:
A nonspecific diagnostic workup is initiated, including complete blood count (CBC), erythrocyte sedimentation rate (ESR) (preferably using the Westergren method), antinuclear antibody (ANA) titer, rapid plasma reagin (RPR) or Venereal Disease Research Laboratory (VDRL) testing, fluorescent treponemal antibody absorption (FTA-ABS) test or microhemagglutination assay for Treponema pallidum (MHA-TP), purified protein derivative (PPD) testing with anergy panel, chest radiograph, and Lyme titer (for cases occurring in an endemic area and as indicated).
The diagnostic workup is supplemented with other tests and subspecialty consultations if the need for any of these measures is strongly indicated by symptoms, history, or physical findings (e.g., determination of angiotensin-converting enzyme level for ruling out sarcoidosis, sacroiliac spine x-ray examination for ruling out ankylosing spondylitis, consultation with a rheumatologist for ruling out psoriatic arthritis).
Treatment
•Patients should be referred to an ophthalmologist within 24 hours.
•A topical cycloplegic agent (e.g., homatropine hydrobromide 5%, atropine sulfate 1%) is administered two or three times a day to stabilize the blood-aqueous barrier, decrease pain, and prevent formation of posterior synechiae.
•A topical corticosteroid (e.g., Pred-Forte 1%, Flarex 0.1%) is administered 4 to 6 times a day. An ophthalmologist initiates this prescription.
Prognosis
•Overall, the prognosis is excellent for patients with a first-time, nongranulomatous anterior uveitis and less favorable for patients with a recurrent, granulomatous type.
Posterior Uveitis
Symptoms
•Vision is commonly decreased or blurred.
•Floaters are seen.
•Redness, pain, and photophobia are occasional symptoms.
•The onset is acute or insidious.
Signs
•The disease can be unilateral or bilateral.
•Inflammatory cells within the vitreous cause a hazy view of the fundus of the eye (Fig. 9–8).
146 CHAPTER 9 • Uveitis
FIGURE 9–8 Inflammatory vitreous cells causing a hazy view |
1 |
|
of the fundus in this case of lens-induced posterior uveitis. |
|
|
Note the large lens fragment (1). |
|
|
|
|
|
FIGURE 9–9 Sarcoid posterior uveitis showing retinal hemor- |
2 |
rhage (1) and vascular sheathing (2). |
|
|
1 |
•Optic disc swelling and edema are observed.
•Retinal and choroidal hemorrhages, exudates, infiltrates, and vascular sheathing are seen (Fig. 9–9). These abnormalities can be difficult to discern without indirect ophthalmoscopy; the view also may be lessened by a constricted pupil and interference from overlying inflammatory cells.
Etiology
•Toxoplasmosis is the most common cause of posterior uveitis (Fig. 9–10).
•In patients with acquired immunodeficiency syndrome (AIDS) who have symptoms of a posterior uveitis, cytomegalovirus retinitis and syphilis should be ruled out or confirmed (see Chapter 10).
•Many local and systemic associations have been noted, as outlined in Box 9–2.
Posterior Uveitis |
147 |
|
|
FIGURE 9–10 Toxoplasmosis lesion located near the optic disc.
Associated Factors and Diseases
Associated disorders include the following:
•Chorioretinal scars
•Exudative retinal detachment
•Macular edema
•Epiretinal membrane
Differential Diagnosis
Considerations in the differential diagnosis include the following:
•Retinal detachment
•Intraocular malignancy (e.g., retinoblastoma)
•Intraocular foreign body
Workup
•A careful history and complete ocular examination are essential.
•The general physical examination is directed at possible systemic findings with the conditions associated with a posterior uveitis.
•A nonspecific diagnostic workup and other tests and subspecialty consultations may be initiated if the need for any of these measures is strongly indicated by symptoms, history, or physical findings.
Treatment
•Patients should be referred to an ophthalmologist within 24 hours.
•Topical cycloplegic and topical corticosteroid agents are administered by an ophthalmologist if anterior inflammation is present.
148 CHAPTER 9 • Uveitis
BOX 9–2 Classification of Posterior Uveitis
Autoimmune disorders
•Vogt-Koyanagi-Harada syndrome (uveoencephalitis)
•Polyarteritis nodosa
•Lens-induced posterior uveitis
Infections
•Toxoplasmosis
•Toxocariasis
•Ocular candidiasis
•Ocular histoplasmosis
•Cytomegalovirus
•Acute retinal necrosis (herpes zoster)
•Tuberculosis
•Syphilis
Malignancies*
•Retinoblastoma
•Malignant melanoma
•Lymphoma
•Leukemia
Other conditions
•Idiopathic disease
•Sarcoidosis
•Behçet’s syndrome
*Noninflammatory conditions in which the clinical findings can mimic those with a posterior uveitis.
•Decisions regarding further treatment (e.g., periocular corticosteroid injections, intravitreal antibiotic injections, systemic medications, potential intraocular surgery) need to be made by an ophthalmologist.
Prognosis
•The prognosis varies greatly depending on the etiology, severity of inflammation, and promptness of appropriate therapy.
CHAPTER 10
Retina
TIMOTHY W. OLSEN
The retina is a highly specialized, neurosensory tissue that forms from an extension of the central nervous system during embryogenesis. Retinal tissue translates focused light energy into a complex series of electrical impulses transmitted through the optic nerve, optic chiasm, and visual tracts to the occipital cortex, resulting in the perception of vision. The examining physician has a unique opportunity, owing to the transparency and clarity of the ocular tissues, to directly examine living, functional neurologic tissue and the accompanying vasculature.
The retinal vasculature may be viewed directly, photographed, or imaged with angiographic dyes such as fluorescein or indocyanine green. The vascular changes seen in the retina often are representative of the systemic vasculature. A skilled clinician will take advantage of this unique window to the human body and incorporate the knowledge gained from ophthalmoscopy into the overall assessment of a patient.
This chapter discusses retinal findings that can serve as a guide for primary care physicians in diagnosing systemic disease and common retinal disorders.
Related Anatomy
The optic nerve is a key landmark that is important for the examining physician to identify during ophthalmoscopy. The optic nerve lies just nasal to the fovea and is best visualized as the examiner approaches the patient’s eye from a slightly temporal approach. As the clinician focuses the direct ophthalmoscope on a retinal vessel, a useful trick to find the optic nerve is to follow a retinal vessel. The retinal blood vessels become larger near the optic nerve. Within the vascular branching pattern, the point of the “V” created by any bifurcation always “points” toward the optic nerve (Fig. 10–1). After visualizing the optic nerve, the clinician focuses the direct ophthalmoscope on the retinal vasculature. The optic nerve is approximately 1.5 to 1.9 mm in diameter, and a retinal vein on the surface of the nerve is approximately 125 mm in
149