Ординатура / Офтальмология / Английские материалы / Optical Coherence Tomography in Age-Related Macular Degeneration_Coscas_2009

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RPE Effraction

This patient was followed for a period of 3 months during which she received 2 intravitreous injections of antiVEGF (Lucentis*) with routine monthly observation by visual acuity, OCT, fluorescein angiography, and ICG angiography.

During these 3 months of follow-up, the various imaging modalities demonstrated satisfactory regression of morphological lesions, which, although already longstanding, showed a remarkable response to treatment. This was demonstrated by retinal thickness measurements with

9 automated comparison to initial measurements on successive graphs (Figure 14).

However, visual function was barely improved, as only subjective symptoms regressed but visual acuity remained relatively low at 20/125 on the last examination.

Spectralis* OCT

▬ By the first follow-up examination, all of the retinal architecture had almost returned to normal.

On the horizontal cross-section, the foveal depression regained a normal structure. The inner retinal layers were well-organized and the outer nuclear layer had a normal appearance.

At this Stage

In this case of advanced CRA, the first 2 injections clearly induced an improvement, at least morphological, with control of exudation and resorption of sub-

retinal and intraretinal fluid (Figure 14).

In view of the good visual acuity in the other eye, the patient considered the result to be fairly satisfactory. Functional and imaging observation was maintained, and the patient was warned about the risk of recurrence over the months to come.

Only multiple localized elevations of the RPE were observed, corresponding to multiple soft drusen.

The external limiting membrane and IS/OS interface were almost intact, except in the juxtafoveal and inferior temporal region, where the RPE was slightly raised (Figure 13a).

On the vertical cross-section, the RPE also had numerous elevations corresponding to drusen with minimal alterations of the outer layers over the dome of the drusen.

In the inferior part of the scan, the neurosensory retina was still abnormally thickened with several cysts. The foveal depression had a normal profile (Figure 13b).

▬At the third examination and after 2 intravitreous injections, the normal appearance of the horizontal cross-section was confirmed with a normal foveal depression and well-organized retinal layers.

Only a small juxtafoveal and temporal PED persisted with adjacent alterations of the external limiting membrane and especially the outer nuclear layer, as well as several bright hyper-reflective spots (Figure 13c).

Due to a moderate adverse drug reaction limited to a rash and at the patient’s request, follow-up angiography was not performed.

In contrast with the cases described above, present-

ing the earliest possible lesions, functional improvement appeared to be more difficult to achieve in this case treated after several months of progression to

these more advanced lesions.

Rigorous long-term observation is essential to guide subsequent treatment.

An 87-year-old woman with bilateral lesions progressing over many years and monocular blindness presented with recent, moderate loss of visual acuity in the left eye.

VA RE: LP - VA LE: 20/32.

tion of an inferior retinal vein with fluorescein leakages partially masked by hemorrhage (Figure 15c, d, and e – enlarged images).

Biomicroscopic Examination

Fairly numerous, non-confluent perifoveal soft drusen and a highly suggestive juxtafoveal hemorrhage, 1/3 DD in diameter, at 5 o’clock (Figure 15a).

Autofluorescence

No changes of the central zone, but presence of granular, perimacular hyper-fluorescence mainly in the inferior

92/3 of the macular region (Figure 15b).

Fluorescein Angiography

A localized zone (measuring about 300 μm) of early, progressive hyper-fluorescence adjacent to the termina-

SLO-ICG Angiography

Barely visible, small, juxtafoveal hyper-fluorescent lesion (Figure 15f and g).

Enlarged image: end-to-end retino-retinal anastomosis between a retinal arteriole and a retinal venule with communication between retinal vessels and the deeper choroidal neovascularization (Figure 15h).

Suggested Diagnosis:

Juxtafoveal retinal hemorrhage, suggesting on early cho-

rioretinal anastomosis with active fluorescein leakage.

Horizontal cross-section

The OCT features were characteristic and diagnostic: discontinuity of the RPE, disruption of the external limiting membrane, alteration of the IS/OS interface, presence of a pre-RPE dense zone, numerous bright hyper-reflective spots, abundant intraretinal fluid, and numerous small cysts.

The juxtafoveal hyper-reflective zone in the inner retinal layers, corresponding to the retinal hemorrhage, showed characteristic posterior shadowing as far as the choroid (Figure 16a).

Vertical cross-section

The cross-section centered on the hyper-fluorescent zone showed the same characteristic signs: discontinuity of the RPE; clearly visible protrusion of the CNV into the retina that appeared to be derived from the choroids, and bulging anterior to the RPE, indicating a chorioretinal anastomosis (Figure 16b).

Anterior to the RPE, increased retinal thickness with subretinal and intraretinal fluid and numerous cysts. The outer retinal layers were altered over the zone of protruding CNV. These signs were associated with numerous bright hyper-reflective spots.

A 91-year-old man with bilateral lesions progressing over many years presented with marked loss of visual acuity in both eyes. VA RE: 20/400.-VA LE: 20/160.

Biomicroscopic Examination

Moderate macular elevation accompanied with several juxtafoveal hemorrhages and a fine crown of lipid exudates. A juxtapapillary lesion surrounded by exudates was also observed (Figure 17a and b).

Autofluorescence

Several perifoveal changes, especially in the peripapillary

9region (Figure 17c).

Fluorescein Angiography

Juxtafoveal and subfoveal zone of hyper-fluorescence predominantly inferior nasal with intense fluorescein leakage, partially masked by hemorrhage (Figure 17d).

SLO-ICG Angiography

Vast oval-shaped, inferior nasal neovascular membrane with a clearly visible peripheral arcade surrounded by hemorrhage.

An inferior nasal retinal vein changed direction at its termination and descended towards the center of the deep choroidal neovascular membrane.

The neovascular membrane was visible against the dark PED which was almost entirely invaded by CNV (Figure 17e).

Suggested Diagnosis:

Vascularized PED with advanced chorioretinal anas-

tomosis communicating with a vast deep neovascular

membrane.

Horizontal cross-section

OCT demonstrated a large subfoveal and juxtafoveal fibrovascular lesion with large cysts and features suggestive of CRA: localized discontinuity of the RPE, disruption of the external limiting membrane and IS/OS interface, pre-RPE dense zone with numerous bright hyper-reflective spots, marked intraretinal fluid, and numerous cysts.

A juxtafoveal hyper-reflective zone in the inner layers corresponded to the retinal hemorrhage with characteristic shadowing (Figure 18a).

Vertical cross-section

The cross-section centered on the hyper-fluorescent zone demonstrated the same characteristic signs: disruption of the RPE and a hyper-reflective lesion anterior to the RPE with a zone of hyper-reflectivity related to deep hemorrhage at its upper limit (Figure 18b).

Anterior to the RPE, increased retinal thickness with intraretinal fluid. The outer layers were altered with a dense area over the zone of protruding CNV with several bright hyper-reflective spots.

The early stages of typical chorioretinal anastomosis have a characteristic appearance: juxtafoveal retinal hemorrhage, angiographic hyper-fluorescence at the macular termination of retinal vessels, and retino-retinal anastomosis communicating with a small choroidal neovascularization.

The SD-OCT image (Spectralis*) is characteristic with disruption of the RPE, protrusion of the neovascularization, an intense exudative reaction, and bright hyperreflective spots.

At this early stage, treatment provides rapid and dramatic improvement (despite persistence of localized alterations of the outer layers and discontinuity of the RPE). However, the effect of treatment appears to be limited, as it usually lasts barely more than 2 months after each injection.

Combination therapy does not appear to be initially indicated at the present time, but long-term follow-up is essential.

Polypoidal choroidal vasculopathy does not constitute part of the classical definition of AMD, but these two entities have a number of features in common.

This entity was initially described as “multiple, recurrent serosanguinous pigment epithelium detachments,” but the most widely accepted term is now idiopathic polypoidal choroidal vasculopathy (PCV) ( Yannuzzi 1997).

SLO-ICG angiography identify and localize these abnormalities in the peripapillary region and also more peripherally. When located in the macular region, they can cause more serious functional impairment.

Clinical Features

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Polypoidal Formations

The name of this disease refers to the presence of choroidal vascular branches with dilated, aneurismal, or polypoidal terminations often grouped like bunches of grapes.

These polypoidal formations can cause leakage and/ or hemorrhage, accounting for the associated multiple, serous, and/or hemorrhagic pigment epithelium detachments.

Polypoidal lesions show delayed filling on angiography with pooling of dye and they remain very hyper-fluores- cent in the late phases.

These polyps are polymorphous, ranging from small and/or solitary to multiple and grouped in various formations.

During the course of the disease, with successive acute exudative or hemorrhagic episodes, the polyps may be relatively difficult to detect in the context of multiple elevations of the retina and retinal pigment epithelium.

Abnormal Choroidal Vessels

The polyps are associated with abnormal choroidal vessels, usually grouped in localized areas, presenting with dilatations and circulatory abnormalities.

These choroidal vascular abnormalities are most clearly visualized on early and intermediate phases of SLO-ICG angiography, which remains the best diagnostic imaging modality.

Two types of abnormal choroidal vessels can be distinguished:

▬A branching network with terminal polyps, or

▬Disseminated polypoidal dilatations on capillaries or relatively fine vessel branches.

The abnormal choroidal vascular network is visible on early and intermediate phases of SLO-ICG. It is usually peripapillary (Figure 1), but can also be observed in the posterior pole and in the macula

Some polypoidal dilatations appear to be attenuated at the end of the angiographic sequence, while others become increasingly hyper-fluorescent with fluorescein leakage. These latter forms appear to be more frequently complicated by hemorrhage.

Hyper-Fluorescent Plaque

A polypoidal hyper-fluorescent plaque is frequently observed in the late phases of the SLO-ICG angiography sequence. This plaque, often extensive, is not always correlated with the normal choroidal vasculature. Intensely hyper-fluorescent zones corresponding to ectasias can be observed in this plaque.

Choroidal Neovascularization

During the long course of this disease, polypoidal choroidal vasculopathy can be accompanied by true choroidal neovascularization, making its diagnosis even more challenging.

Polypoidal choroidal vasculopathy is observed at a relatively young age, usually without drusen. Lesions are not confined to the macula and choroidal neovascularization remains a relatively rare complication.

These features clearly distinguish PCV from the usual form of AMD.