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

Fig. 7.13a–d. A 30 year old patient with chronic, relapsing iridocyclitis for the past ten years, caused by a rheumatoid disease (Bechterew’s, or StrümpellMarie disease). The acuity in the right eye was 20/50. a Fundoscopy shows no unusual findings. Fluores-

cein angiography in the early phase b is unremarkable. In the subsequent course of the study c and in the late phase d there was a diffuse disturbance of the blood/retinal barrier with visualization of a pronounced level of macular edema.

grow ever larger. Also, choroidal neovascularization can arise at the margins of the scarred areas.

Autofluorescence

Autofluorescence is completely extinguished in the scarred areas.

Fluorescein Angiography

In the early phase new lesions block the background fluorescence. In the course of the angiogram leakage of dye appears in and around the active lesions. Frequently there are adjacent areas of scarring that appear hyperfluorescent, due to the atrophy of the retinal pigment epithelium. Since the choriocapillaris in the scarred area is also atrophic, the larger choroidal vessels are clearly visible.

Fig. 7.14a–f. A 32 year old patient with an acute bout of serpiginous choroiditis in the left eye. a Fluorescein angiography in the early and mid phase show a hypofluorescent area the size of 5 disc diameters above the superior vascular arcade. This area corresponds to that of the active inflammatory lesions, which cause blockage of the background fluorescence. In the immediately adjacent areas there are hyperfluorescent scars which are the healed vestiges of prior inflammatory activity. b In the late phase diffuse leakage of dye appears in the region of active choroiditis. c,d The same patient 2 years later: large zone of atrophy of the RPE and the choriocapillaris

at the location of the prior inflammation. The atrophic zone reaches all the way to the fovea; the acuity is 20/20. While on immunosuppressive therapy, there have been no additional bouts of inflammatory disease. e,f The right eye of the same patient shows a large area of scarring in the posterior pole, caused by prior activity of serpiginous choroiditis. Due to preservation of a small island that includes the fovea, acuity remains 20/20. The fluorescein angiographic appearance of an old, no longer active, serpiginous choroiditis is characteristic and is marked by the presence of a hyperfluorescent margin of scarring that retains its serpiginous shape.

8.1Congenital Anomalies of the Optic Disc

8.1.1Oblique Insertion of the Optic Nerve

Oblique insertion of the optic nerve is typically seen as a tilting of the optic disc in an inferior or inferonasal direction. The disc appears unusually oval and the inferonasal quadrant of the disc is relatively pale. Frequently the temporal retinal vessels move at first in a nasal direction before turning about to sweep toward the temporal half of the fundus.

Fluorescein Angiography

The fluorescein angiographic appearance of an obliquely inserted optic nerve has no significant

8feature that differentiates it from an otherwise normal optic disc. With a pronounced degree of optic disc tilting the obliquely inserted optic

Fig. 8.1a–c. Oblique insertion of the optic nerve, left eye. a The optic disc markedly tilted inferonasally and with an oval shape. The temporal branches of the central retinal artery and vein initially move in a nasal direction when crossing the border of the disc,

nerve can be associated with an ectasia of the ocular wall, i.e. the ocular wall is thinned and drawn out in an inferonasal direction. This usually is found in company with a marked refractive error that makes parts of the fundus out of focus during the angiogram.

8.1.2 Myelinated Nerve Fibers

Myelinated nerve fibers are axons of the retinal ganglion cells which have acquired a myelin sheath, due to a developmental anomaly of myelin formation during the first months of life.

Fundus

A white, opaque coloring of the nerve fiber layer. Variation of the myelin formation along the individual nerve fibers causes the edges of the myelinated area to appear feathered or indistinct.

but then turn back to supply the temporal half of the fundus. There is an ocular wall ectasias inferonasal to the optic disc. b,c During confocal fluorescein angiography either the nasal b or the temporal c region of the fundus can be in focus, but not both.

Fig. 8.2a,b. a Myelinated nerve fibers at the superonasal margin of the optic disc. b The myelinated

fibers block the fluorescence during fluorescein angiography.

The myelinated nerve fibers block both the autofluorescence and the background fluorescence phenomenon during angiography.

8.1.3 Drusen of the Optic Disc

Drusen of the optic disc are deposits of mucopolysaccharides, nucleic acids and calcium in the disc tissues ( Fig. 8.3). The scleral canal is normally narrow and the optic disc area is relatively small. Even though the papillary drusen usually remain asymptomatic throughout one’s life span, some authors think they may be a cause of slowly progressive degeneration of the optic nerves. In children the drusen lie deep beneath the surface

8of the disc and are hard to find. During the second decade of life the drusen become visible as tiny, pearl-like, and elevated groups of spheres clustered together. Rarely, a parapapillary choroidal neovascular membrane is associated with drusen of the optic disc ( Fig. 8.4).

Optic disc drusen are usually asymptomatic. Occasionally, nerve fiber bundle defects appear in the visual field, corresponding to the course of the fibers damaged by the drusen. Such visual field defects usually do not reach the center of the field and are often not noticed.

Autofluorescence

The material deposited in the drusen is clearly autofluorescent. The autofluorescence of drusen is visible, only if they are prelaminar in location (anterior to the lamina cribrosa). Drusen in deeper tissues, as they some times develop in children, are not ordinarily visible by autofluorescence.

Fluorescein Angiography

Fluorescein angiography offers no additional advantage and is indicated only when there is suspicion of, for example, the presence of a choroidal neovascular membrane.

Fig. 8.4a–f. Parapapillary choroidal neovavascularization in association with drusen of the optic disc. A 13 year old patient with a history of several months duration of symptomatic blurring of vision in the right eye. a,f Fundoscopy finds bilateral disc elevation with drusen. To exclude papilledema and a possibly elevated level of intracranial pressure, a cerebral MRI was done and the CSF pressure was measured. No signs of pathology were found. The right eye a has a lightly pigmented lesion located temporal to the optic disc with an appearance consistent with a long-standing, scarred focus of parapapil-

lary choroidal neovascularization. Lipid exudation is seen particularly in the superior sector of the lesion. Temporal to the lesion is a disturbance with some atrophy of the RPE (arrow). Secondary RPE changes of this sort typically appear and are caused by chronic leakage of plasma into the subretinal space. b Autofluorescence imaging demonstrates several foci of elevated signal level in the region of the optic disc. c–e Fluorescein angiography reveals choroidal neovascularization with fluid leakage e temporal to the optic disc. The area of RPE atrophy is clearly marked as a zone of hyperfluorescence.