Ординатура / Офтальмология / Английские материалы / Practical Manual of Intraocular Inflammation_Dick, Okada, Forrester_2008

Figure 1 Binocular indirect ophthalmoscopic grading of vitreal haze (2). This composite fundus color image has been photographically enhanced to demonstrate the effects of vitritis/vitreal haze. (A) Normal view (grade 0). (B) Hazy view of posterior pole (grade 2). (C) Increasingly difficult to discern retinal vascular features (grade 3). (D) Barely visible retinal structures (grade 4).

that pars planitis should be used for that subset of intermediate uveitis (with predominant inflammation in the vitreous) where there is snowbank formation, in the absence of associated infection of systemic disease.

Symptoms Vitritis, which is the predominant site of inflammation in intermediate uveitis, may be asymptomatic. However, when in context of panuveitis or retinal vasculitis, vitritis may also present with loss of vision (see below). In general, vitritis gives rise to the following symptoms:

l Floaters

lBlurring of vision, which may change with posture or eye movements and may effect stereopsis

lReduced vision in case of significant vitreous opacity or in presence of acute posterior vitreous detachment

Clinical assessment Of course, the clarity of visualizing the posterior pole with a 20-Dioptre or 90-Dioptre Lens via indirect biomicroscopy will depend on both the clarity of the cornea and the presence of cataract. Therefore, all binocular indirect ophthalmoscopy (BIO) score assessments (2) of vitreous haze should also be made in conjunction with cataract assessment [e.g., lens opacity classification (LOCS) III (3)].

Figure 2 Fundus color photographs showing snowbanking in pars planitis. A snowbank in the inferotemporal peripheral retina (right). In extreme cases (left), snowbanking may extend and associated retinal vasculitis and leakage create exudation and subretinal fluid. The ensuing detachment may encroach to the macula and reduce vision.

Vitreous cells are best seen with slit-lamp biomicroscopy, with or without additional lens systems to view the posterior vitreous. On examination, you may note anterior vitreous cells (pertaining to those cells in retrolental space) and posterior vitreous cells in the cortical gel and in presence of posterior vitreous detachment in the retrohyaloid space. A classical sign, for example, of intermediate uveitis is snowballs, where large cellular aggregates accumulate inferiorly in the posterior vitreous gel. In extreme cases, there is a cellular and glial accumulation on the pars plana and anterior retina, termed snowbanking (Fig. 2). This is best visualized by 20D indirect ophthalmoscopy, and indentation is required to exclude its presence.

Retinal Vasculitis

There are many features of vascular changes in PSII, and not all embody the overarching term retinal vasculitis. Additionally, there is little evidence to support the term retinal vasculitis in terms of inflammation of the vessel pathologically as seen in biopsies of systemic vasculitides. Although we recognize that systemic vasculitis can present with intraocular inflammation, the retinal vasculitis we commonly observe clinically is a result of infiltrating retinal inflammatory cells creating a perivascular cuff or a result of vascular occlusion (Fig. 3). Retinal vasculitis is potentially sight-threatening and more frequently affects the retinal venules rather than arterioles. Retinal vasculitis may exist as a predominant sign in posterior uveitis, but is also seen in most other forms of PSII, including intermediate uveitis and in posterior uveitis such as chorioretinitis or in association with systemic disease (Table 4).

Figure 3 Fundus color photographs and fluorescein angiographs. (A, B) Venous sheathing or cuffing is a characteristic sign of retinal vasculitis. (C, D) Vasculitis may lead to closure of the lumen with resulting retinal swelling, hemorrhage, and cotton wool spots in the territory served by the affected vein. Fluorescein angiography may be used to demonstrate retinal ischemia (D, E, boxed regions), vessel wall staining and leakage (F, arrow), and cystoid macular edema (I, arrow). Neovascularization may also occur (G, H, arrowheads). Source: From Ref. Hughes EH, Dick AD. The pathology and pathogenesis of retinal vasculitis. Neuropathology and Applied Neurobiology (2003); 29:325–340.

Source: Adapted from Ref. Hughes EH, Dick AD. The pathology and pathogenesis of retinal vasculitis. Neuropathol Appl Neurobiol 2003; 29:325–340.

Abbreviations: HSV, Herpes simplex virus; VZV, Varicella zoster virus; CMV, cytomegalovirus; EBV, Epstein-Barr virus.

Symptoms It is often asymptomatic, unless associated with panuveitis or intermediate uveitis, where floaters and loss of vision may occur more acutely. Symptoms of retinal vasculitis occur as a result of complications of retinal vasculitis and include

lloss of vision resulting from macular ischemia or vitreous hemorrhage secondary to retinal neovascularization,

In one sample of 150 patients with PSII of predominant features of retinal vasculitis, 45% of cases have isolated ocular disease, and the remainder are associated with systemic inflammatory disorders. Of note was that two-thirds of patients were under 40 years of age, with a female preponderance. In most studies, the condition was notably bilateral in most cases, and the worse prognosis was seen in those cases with retinal ischemia as a result of retinal vascular occlusion.

In summary, active retinal vasculitis is observed with signs of

l retinal vessel engorgement and irregular dilatation,

lretinal vascular leakage—retinal edema, blurring of vascular margin, and then sheathing, and

lretinal vascular occlusion—leading to swelling, hemorrhages and exudates, and finally neovascularization.

Figure 4 Composite fundus color photograph of patients with retinal vasculitis. (A) Posterior vasculitis presenting as venous stasis, showing tortuous vessels with irregular margins (arrows) and associated hemorrhages. (B) Peripheral vasculitis showing sheathed vessel. (C) Central vasculitis demonstrating blurred margins of optic nerve head (arrowhead ) with capillary dilatation and central macular vasculitis with exudates.

Clinically, we can further define retinal vasculitis with respect to the fundal topography of retinal vascular involvement (Fig. 4).

lPeripheral retinal vasculitis—often low-grade and associated with blurring of vascular margins or sheathing of vessels with or without perivascular hemorrhage. Clinical assessment to distinguish between active and inactive vasculitis can be difficult. However, often when

inactive, the sheathing is well-defined.

lPosterior retinal vasculitis—often presenting with occlusive disease with branch venous occlusion or venous stasis, with blurring of vessel margins, tortuous vessels, perivascular hemorrhages, and retinal swelling.

Often results in chronic blood-ocular barrier breakdown and persistent cystoid macular edema.

lCentral retinal vasculitis—where retinal vasculitis affects the optic nerve head or macular branches, resulting in disk swelling, venous and optic

of some of the posterior uveitides. Characteristically, this may not be identified unless there are associated pigment epithelial changes, without angiography (see below). Occlusive choriocapillaris disease is observed as a primary event in Systemic lupus erythematosus (SLE) and related anti-phospholipid syndromes and lymphoproliferative disease but also forms part of inflammation in white dot syndromes and acute posterior multifocal placoid pigment epitheliopathy (APMPPE), and awareness about other posterior uveitides is increasing.

In summary, retinal vasculitis is a descriptive term in which there is evidence of intraocular inflammation in the presence of predominant retinal vascular changes. As such we will not be discussing occlusive vasculopathies in the absence of any signs of inflammation such as anti-phospholipid syndromes.

When clinically assessing a patient for retinal vasculitis, the following are of particular note:

lPresence of hemorrhages and exudates (often signs of severe disease and/ or occlusive disease)

Chorioretinitis

Chorioretinitis represents cellular infiltrates within the choroid and outer retina and can occur as single, multifocal, discrete small to large confluent lesions in many forms of posterior uveitis (chap. 3). More particularly, chorioretinitis is found associated with predominant vitritis in intermediate uveitis and also in panuveitis as well as milder, more chronic inflammatory conditions in which there is largely an absence of vitritis, the white dot syndromes. Their presence can be characteristic of both certain infectious and noninfectious conditions, but beware, there is considerable overlap.

Symptoms Classically their presence is associated with scintillation and, more rarely, photopsia. However, again, as we have discussed in relation to retinal vasculitis, symptoms may vary as to whether the chorioretinitis occurs as part of a more profound intraocular inflammation such as panuveitis.

In summary,

lwhen the choroiditis is either peripapillary or at the macula, then reduced vision may occur acutely,

lif insidious, at the onset of chorioretinitis, there may be symptoms relating to positive scotomata,

lmetamorphopsia and blurring of central vision occur either because the choroiditis is at the macula or secondary to adjacent retinal edema,

inflammation-induced choroidal neovascularization,

lin milder forms of chorioretinitis (white dot syndromes), there may be associated visual loss, which improves over several weeks, or signs of metamorphopsia/micropsia, which again resolve, and

lscotoma may occur as a result of associated enlarged blind spot in association with white dot syndromes.

Signs Chorioretinal lesions are very varied in their presentation. As you will see in chapter 3, some chorioretinal features and phenotype permit almost “specific” diagnoses to be recognized. However, chorioretinal lesions are obviously best visualized with indirect ophthalmoscopy, but remember

i.their features may vary throughout the course of disease

ii.there is considerable overlap and chorioretinal lesions are not always readily diagnostic (multifocal choroiditis, punctuate inner choroidopathy, ocular histoplasmosis).

iii.It is necessary to define activity to best appropriate immunosuppressive therapy where and when required.

Clinically, activity is defined by (Fig. 5)

lill-defined margin of lesion (as opposed to discrete margins of inactive lesions),

Retinitis, even without vitritis or anterior segment inflammation, may be the only feature of overlying vasculitis. Retinitis is observed frequently in patients with infection, who are systemically immunocompromised (see below, Fig. 6, and chap. 3).

As part of the signs of PSII, chorioretinitis may of course coexist in patients with posterior uveitis, where both vitritis and retinal vasculitis are present (Fig. 7). Activity therefore can be noted and demonstrated by the appearance of chorioretinal lesion, retinal vasculitis, and the BIO vitreal haze score.

Figure 5 Composite fundus color photographs displaying spectrum of chorioretinitis. (A) Multifocal choroiditis. Active lesions, which are creamy and have indistinct margins (arrows). (B) Discrete unifocal lesion, which is again creamy and has indistinct margins (arrowhead ) with associated hemorrhage (arrow), characteristic of a patient with Toxoplasma chorioretinitis. (C) Ill-defined edges of creamy confluent peripapillary lesions of serpiginous choroidopathy (arrow) (D) Small outer retinal/ choroidal lesions (arrows) of a patient presenting with scintillation and metamorphopsia due to multiple evanescent white dot syndrome (MEWDS).