Ординатура / Офтальмология / Английские материалы / Handbook of Pediatric Retinal Disease_Wright, Spiegel, Thompson_2006

FIGURE 11-1A,B. (A) Peripheral “snowbanking” is the hallmark of pars planitis. (B) Angiographic appearance of cystoid macular edema, the most common cause of visual loss in patients with pars planitis.

blurred vision and floaters but do not usually complain of pain or photophobia. Up to 80% of cases are eventually bilateral. Anterior chamber inflammation is usually mild or absent although children seem to have more anterior chamber inflammation than adults. The snowbank opacities along the pars plana are characteristic of the disease but are sometimes present

in only one eye of a patient with bilateral inflammation. The snowbanks represent fibroglial masses and are most commonly seen inferiorly. Peripheral neovascularization may occur along an area of snowbanking and vitreous hemorrhage can occur. Optic disc edema may be seen, more commonly in children, in whom it occurs in up to 50% of cases. In cases of severe vitritis, children may present with decreased red reflexes.

The course of pars planitis is variable. Inflammation is usually chronic but may not result in severe visual loss. The amount of visual loss is usually related to the presence of cystoid macular edema (CME) (Fig. 11-1B). CME is typically worse in patients having more inflammation. Cataracts, glaucoma, and retinal detachments may also cause visual loss in these patients. Vitreous hemorrhage is an important cause of visual loss in children with pars planitis. In addition, about 16% of patients with pars planitis develop optic neuritis or multiple sclerosis. There are no characteristic laboratory abnormalities. The differential diagnosis of pars planitis includes sarcoidosis, tuberculosis, syphilis, toxocariasis, and toxoplasmosis. Conversely, a pars planitis-like inflammation may also be seen in patients with multiple sclerosis.4

Treatment of pars planitis with corticosteroids is often effective. Corticosteroids can have significant ocular and systemic side effects and should be used with caution. Aggressive treatment is indicated in cases of visual loss from 20/20 or severe floaters that cause visual impairment. Periocular steriods (20– 40 mg triamcinolone diacetate per injection) are the first line of treatment, especially for unilateral cases. More than one injection may be necessary to achieve a decrease in inflammation or resolution of CME. Intraocular corticosteroids may also be considered and appear to be of significant value. Cryotherapy or laser photocoagulation to areas of snowbanking or to the retina behind the snowbanking may be effective in decreasing inflammation in some cases and can decrease peripheral neovascularization. Oral corticosteroids (1–2 mg/kg per day, tapering 5– 10 mg/wk), may be effective, although significant side effects are common with prolonged treatment, and treatment for longer than 3 weeks should be avoided. Methotrexate, cyclosporine, or chlorambucil may be effective and can decrease peripheral neovascularization, but should be reserved for severe cases.21,31a,35 These agents, particularly cyclosporine, should be used with great caution. Peripheral scatter photoaocagulation41 is also useful in treating vitreous base neovascularization. Pars plana

elevated serum ACE supports the diagnosis of sarcoidosis. Random conjunctival biopsy (when no nodules are seen) has been advocated by some and may be useful in some cases.33

The differential diagnosis of ocular sarcoidosis includes many entities. In children, one must consider juvenile rheumatoid arthritis and pars planitis. Other diseases that may have a similar presentation include sympathetic ophthalmia, Behcet’s disease, and the “white-dot” syndromes.37

Corticosteroids are effective in treating ocular (and systemic) manifestations of sarcoidosis. Acute iridocyclitis responds well to topical corticosteroids. Chronic granulomatous uveitis may require periocular, intraocular, or systemic steroids. In treating children, one must remember the severe side effects of chronic systemic corticosteroids and limit their use when possible. Choroidal lesions are associated with CNS sarcoidosis and appropriate evaluation is required.

OCULAR TOXOCARIASIS

Ocular toxocariasis is caused by invasion of the eye by larval forms of the dog roundworm, Toxocara canis or, rarely, by the cat roundworm, Toxocara cati. The first cases of ocular toxocariasis to be described were patients who had undergone enucleation for suspicion of retinoblastoma.57 Most of these patients had dense vitreous inflammation (vitreous abscess) and retinal detachment. The more common presentation is a gray to white mass in the posterior pole or retinal periphery (a focal granuloma) with variable amounts of vitreous inflammation (Fig. 11-3). The inflammation may resolve over time. Vitreoretinal traction bands may be seen extending from the mass. Pathologically, the mass lesion represents a choroidal granuloma. Peripheral inflammation similar to that seen in pars planitis has also been described, but only one eye is usually afffected.20 Ultrasound biomicroscopy may identify characteristic pseudocysts in the peripheral vitreous of affected eyes.54 In some cases, there are no overt signs of inflammation and a child may present with strabismus or poor vision on screening tests. The disease is usually unilateral and almost always occurs in children. The diagnosis is usually made clinically, but serum antibody titers determined by enzyme-linked immunosorbent assay (ELISA) may be helpful in some cases. Titers are often lower in patients with ocular toxocariasis than in those with visceral larva

following). Table 11-2 summarizes the distinguishing features of these two entities.

JUVENILE RHEUMATOID ARTHRITIS

Juvenile rheumatoid arthritis (JRA) is a group of disorders characterized by persistent arthritis with an onset before 16 years of age. Certain types of JRA are associated with a high incidence of uveitis. The predominant ocular manifestation of the disorder is chronic iridocyclitis. A few patients may have significant vitritis, but the posterior vitreous is usually clear. The uveitis may initially be asymptomatic but can cause severe visual disability in some patients. Glaucoma, band keratopathy, anterior and posterior synechiae, cataracts, and cystoid macular edema may occur (Fig. 11-4). The uveitis is most commonly seen in young girls under age 5 with pauciarticular arthritis (four or fewer joints involved at onset of disease) and positive antinuclear antibodies (ANA).7

Treatment of chronic uveitis in patients with JRA is often difficult. Topical, periocular, or possibly intraocular corticosteroids are the treatment of choice. Oral corticosteroids should be avoided if possible because of the chronic course of the

FIGURE 11-4. Patient with juvenile rheumatoid arthritis, showing the sequelae of chronic anterior uveitis that include posterior synechiae and cataract formation. Band keratopathy is also seen in many of these patients.

disease and many side effects of the treatment, but aggressive treatment is required. It may not be possible to clear the anterior chamber of cells, and the flare often persists after adequate treatment, but aggressive treatment is required.34 Many children will be on systemic methotrexate, which may have a steroidsparing effect. Systemic cyclosporin A is effective in many refractory cases.21 Etanercept, which neutralizes tumor necrosis factor- , may also be effective in certain cases of treatmentresistant cases; however, further research is needed regarding its effectiveness in ocular disease.46

OCULAR TOXOPLASMOSIS

Ocular toxoplasmosis results from infection with the protozoan parasite Toxoplasma gondii. Congenital toxoplasmosis is classically described as a triad of convulsions, cerebral calcifications, and retinochoroiditis. If the fetus is infected in the first trimester, the resulting illness may be severe, with microcephaly, seizures, intracranial calcification, hydocephalus, jaundice, and organomegaly. Retinochoroiditis is present in 75% to 80% of cases.8,48 Microphthalmos, optic atrophy, anterior and

posterior uveitis, strabismus, and nystagmus may also be seen. Histopathologic features include retinitis, retinal necrosis, RPE disruption, choroidal inflammation and congestion, and optic neuritis.47 Infections acquired later in gestation are typically less severe and may initially be asymptomatic. Some patients present with strabismus or poor vision on screening examinations due to macular scarring. Some cases of “acquired” toxoplasma retinochoroiditis are probably the result of reactivation of congenitally acquired infection.42

Older patients with active ocular toxoplasmosis often present with complaints of decreased vision and floaters. A focal area of retinitis is often seen adjacent to an old scar (Fig. 11-5A). The active area is fluffy and white and has an overlying vitritis. When vitreous inflammation is intense, the classic “headlight- in-a-fog” presentation is seen, representing an area of retinitis seen through vitreous haze (Fig. 11-5B). A typical attack may last a week to several months despite treatment. The visual prognosis depends mainly on the presence or absence of macular involvement. Papillitis is rarely seen but is a cause of permanent visual loss in some patients. Punctate retinal lesions have also been described.14 One study found a 6% incidence of retinal detachment and an additional 5% incidence of retinal breaks in 150 patients with ocular toxoplasmosis.6 Patients with severe inflammation and myopia were at greatest risk. The diagnosis is made when a typical fundus lesion is found in a patient with positive serological testing. The presence of IgG or IgM antibodies in serum can be detected by indirect immunofluorescence or ELISA. Neonates with congenital infections may demonstrate IgM antibodies in the cerebrospinal fluid (CSF). Because many patients without active toxoplasmosis may have positive antibody titers, the diagnosis is mainly a clinical one, with serology playing a supportive role. More recent work has shown that polymerase chain reaction of blood, aqueous, and vitreous can identify T. gondii DNA.18,32

Congenital infections should be treated agressively for a duration of 1 year. Triple drug therapy with pyramethamine, sulfadiazine, and leukovorin (folinic acid) is clearly superior to treatment for 1 month or no treatment.29,30,48 Prednisone is added for elevation of CSF protein and for vision-threatening chorioretinitis. Prolonged triple-agent treatment has been shown to lead to quite favorable neurological and ophthalmologic outcomes, despite severe disease at presentation.29,30,48 Therefore, early, accurate diagnosis and prompt referral are imperative.

FIGURE 11-5A,B. (A) Active inflammation at the edge of an old chorioretinal scar in a patient with toxoplasmosis. (B) Classic “headlight-in- the-fog” appearance of active toxoplasmosis represents a posterior pole inflammatory mass seen through the haze caused by posterior uveitis.

In older patients, treatment should be considered if the macula or optic nerve is threatened or if the patient is immunodeficient. Triple-drug therapy also is commonly used in older patients [pyrimethamine (50 mg loading dose, then 25 mg orally twice a day), sulfadiazine (1g orally four times a day), and pred-