Ординатура / Офтальмология / Английские материалы / Fluorescence Angiography in Ophthalmlogy_Dithmar, Holz_2008

Fig. 7.8a–d. A 65 year old HLA-A29 positive patient with birdshot chorioretinopathy. a Fundoscopy (left eye) shows depigmentation located nasal to the temporal large vessels with a well demarcated, pale yellow, striated appearance which is typical for this disease. The structures along the inferotemporal vascular arcade appear faded. b The autofluorescence image shows an irregular distribution of fluorescent intensity. c,d Simultaneous

nent in the nasal fundus. In addition, there can be vasculitis, vitreous cells and cystoid macular edema.

Autofluorescence

The autofluorescence levels change irregularly, and as a rule are they not diagnostically helpful.

Fluorescein Angiography

The characteristically striate lesions are only poorly visible on fluorescein angiograms. Corresponding to the extent of their associated vasculitis, there can frequently be both hyperfluorescence and leakage of dye in the vicinity of the large vascular arcades during the course of the study.

ICG Angiography

The ICG angiographic findings can include an irregular choroidal filling pattern. Compared to the extent of funduscopically visible lesions, however, the change in choroidal filling is low-grade. Clearly visible areas of hypofluorescence, as seen other »white dot syndromes«, are not found.

fluorescein angiography (left half images) and ICG angiography (right half images). The fluorescein angiogram shows hyperfluorescence, especially along the vascular arcades with increasing leakage of dye in the course of the study, while the ICG angiogram d is relatively unremarkable and shows no filling defects in the vicinity of the funduscopically visible changes.

(For findings of the contralateral eye see e,f below).

7.7 · Perivasculitis

7.7Perivasculitis

Perivasculitis retinae refers to an inflammation of the retinal vessels with vascular sheathing. The retinal veins are more frequently involved than are the arteries. Perivasculitis can be caused by any number of diseases. Among the group are sarcoidosis, collagenosis retinopathy, multiple sclerosis, and infections, such as tuberculosis, syphilis, and toxoplasmosis. In some patients the etiology remains unknown, often despite extensive diagnostic testing. It is assumed that these cases represent a form of autoimmune disease.

Fundus

Ophthalmoscopy shows off-white sheathing of the vessels, that as a rule appears only in portions of the arteries or veins, i.e. a segmental pattern.

Autofluorescence

In the area of sheathing there is an irregular blockage of autofluorescence, so that the affected vessel segments have indistinct margins.

Fluorescein Angiography

In the regions of the affected vascular segments there is an elevated permeability with leakage of fluorescein. This causes an increasing accumulation of dye that grows throughout the course of the angiogram.

ICG Angiography

Unlike the smaller molecules of fluorescein, the ICG molecules show no signs of leakage. The inflammatory changes in the affected vessel segments block the fluorescence somewhat, which is why the ICG fluorescence in these areas appears to remain confined to the intravascular blood columns.

7.7.1 Occlusive Retinal Vasculitis

Occlusive retinal vasculitis is a particular form of vascular wall inflammation which presents with vascular occlusions that lead to corresponding areas of retinal ischemia. Certain disorders, such as Behçet’s disease ( Fig. 7.10) present with this type of vasculitis.

Fig. 7.9a,b. A 45 year old patient with uveitis intermedia and multifocal periphlebitis. a Fluorescein angiography detects numerous retinal venous vascular segments with definite leakage of dye as a sign of segmental inflammatory damage to vascular wall perme-

ability. b In the corresponding ICG angiogram there is no leakage. The zones of periphlebitis can cause blockage of the ICG fluorescence, and vascular wall edema can narrow the blood column to produce an hour-glass shaped restriction to blood flow (arrow).

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b

Fig. 7.10a,b. A 53 year old patient with the perivasculitis of Behçet’s disease. a Long segments of sheathing of the peripapillary retinal arterial vessels. b Simultaneous fluorescein angiography (left image) and ICG angiography (right image): In the fluorescein

angiogram there is in addition to a diffuse peripapillary leakage, a leakage of the superotemporal retinal artery superior to the optic disc, where this vessel is thickened, while the ICG study shows no leakage in this location.

Fig. 7.11a,b. A 40 year old patient with occlusive retinal vasculitis of uncertain origin. The visual acuity of the left eye is 20/100. a,b Simultaneous fluores- cein-ICG-angiography of the left eye. a Fluorescein angiography shows definite macular edema. Nasal to the optic disc is a circa 9 disc diameters wide area

of retinal ischemia. There are abrupt retinal vascular terminations. b ICG angiography shows no damage to the choroidal circulation. The area of retinal ischemia is barely noticeable, due to the good visualization of the choroidal circulation. There is no leakage of ICG in the macula.

Fig. 7.12a–f. A 52 year old patient with bilateral occlusive vasculitis of uncertain cause. a Fundoscopy shows sheathing of the inferotemporal artery. b–d Fluorescein angiography shows a complete occlusion of the inferotemporal artery. The area supplied by this vessel is ischemic, the capillaries bordering

on the area of ischemia are telangiectatic, and there is leakage of dye in the late phase d. e,f The right eye has paracentral retinal hemorrhages and cotton wool spots along the course of the superotemporal artery. Fluorescein angiography shows the broad area of ischemia.

7.8Inflammatory Macular Edema

Intraocular inflammation can lead to a generalized disturbance of the blood-retinal barrier in the regions fed by the retinal vessels and also in the outer retinal layers. This in turn can cause diffuse, cystoid macular edema.

Fluorescein Angiography

While the early phase of the study can be unremarkable, the middle phase shows a diffuse leakage of dye. In the late phase the extent of the macular edema is clearly recognizable. The angiographic findings often show the macular edema more impressively than the funduscopic findings might suggest.