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

Clinical signs

A 75-year-old man presented for the first time with a slowly progressive decline of vision in his right eye without complaints of metamorphopsias. He did not notice the symptoms initially because of good vision in his fellow eye.

VA RE: 20/32 - VA LE: 20/25.

Biomicroscopic examination: demonstrated an ovalshaped, relatively flat macular elevation with several poorly visible juxtafoveal hemorrhages (Figure 25) and numerous, non-confluent soft drusen. They were espe-

8cially noticeable in the temporal macular zone and there were no associated lipid exudates.

Autofluorescence showed a very extensive, clearly demarcated, intensely hyper-fluorescent oval-shaped lesion with little alteration of xanthophyll pigment. This autofluorescent zone extended inferiorly, suggesting an alteration of the RPE and the presence of SRF.

Fluorescein Angiography

Relatively early, heterogeneous hyper-fluorescence with several areas of pinpoint leakage in the macular region.

This zone, slightly over 3 DD, gradually stained with late and moderate leakage (Figure 24).

SLO-ICG Angiography

(a)Early phase: vast, rounded, well-delineated, subfoveal hypo-fluorescent lesion, indicating a pigment epithelium detachment. A choroidal neovascular membrane was clearly visible against this dark background, which occupied almost the entire surface of the lesion (Figure 24).

(b)Late phase: this neovascular membrane became clearly visible on ICG angiography and was drained by several inferior vessels encroaching in the center.

Suggested Diagnosis:

Large, isolated subfoveal occult choroidal neovascular-

ization.

Horizontal section

In the RPE, presence of moderate but fairly wide elevation with thickening. This PED was irregular, bi-lobed, with a central hyper-reflective area.

The PED cavity was hypo-reflective but not optically empty with several more reflective irregularities posterior to the RPE and in the center, at the site of neovascularization. Bruch’s membrane was poorly visualized. There was moderate posterior shadowing (Figure 25a).

Anterior to the RPE, the neurosensory retina was slightly thickened with partial disorganization of retinal layers that were poorly distinguished.

Slight intraretinal fluid caused partial loss of the foveal depression. A hypo-reflective SRF was visible at the edge of the lesion with no cysts and no intraretinal hyperreflective structures.

Vertical and oblique sections

The appearance was almost identical, suggesting that the PED and neovascularization occupied a regular, rounded zone (Figure 25b and c).

The hyper-reflectivity, more intense in the center, was probably related to neovascularization and associated fibrosis.

The response to treatment of monthly intravitreal injections of anti-VEGF (Lucentis*) was monitored with visual acuity, OCT, fluorescein angiography, and ICG angiography.

During the first year, the patient was followed by conventional imaging and Stratus* TD-OCT (Figure 26).

During the second year, follow-up imaging was performed with simultaneous angiography and SD-OCT

8(Spectralis*) (Figure 27).

Follow-Up during the First Year

Visual acuity initially declined and then improved after the second injection, before stabilizing at 20/25 throughout this initial period.

TD-OCT

On the first follow-up examination

Retinal thickness gradually decreased and intraretinal fluid resolved. The foveal depression became more clearly visible and retinal layers became more distinct (Figure 26a).

After the second injection

A layer of subretinal fluid was observed that persisted and increased despite improvement of visual acuity (Figure 26b-e).

At this Stage

The lesion appeared to be stabilized with good VA. This improvement justified suspension of IVT injec-

tions (Figure 26e).

Subjective and objective improvement was obtained rapidly after the second injection, with restoration of visual acuity to 20/25 that remained stable on several successive examinations. Suspension of treatment is temporary and can only be considered to be definitive after long-term follow-up.

The pigment epithelium detachment became flatter, more irregular, and wavy, with a moderately reflective cavity (false green color) suggesting progressive organization with no intraretinal fluid.

After the fourth injection

The imaging signs remained stable and visual acuity remained normal (Figure 26c and d).

IVT injections were therefore stopped, while maintaining follow-up imaging every two months for the first year.

Fluorescein Angiography

The irregularly hyper-fluorescent lesion remained almost stable with the appearance of a few hypo-fluorescent defects.

However, the lesion did not increase in size and did not present any signs of new hemorrhage (Figure 26c, d, and e).

ICG Angiography

The neovascular membrane remained visible, and large vessels were well perfused at each examination.

However, the membrane appeared to be thinner and limited to the two inferior draining vessels (Figure 26c, d, and e).

This functional improvement contrasted with the

persistent SRF visualized by OCT, which may correspond to transient intraretinal fluid before complete

resorption.

This contrast between clinical and OCT signs required a very cautious attitude during the second year. Follow-up was maintained and subsequently used SD-OCT.

Chapter 8 · Clinical Features and Natural History of AMD on OCT

CLINICAL CASE No. 07: LARGE OCCULT CNV

Follow-up after treatment

a1st month

…………………..V-PED…………….........

b2nd month

SRD

………V-PED……………

Green

After-IVT-1----20/50

Green

After-IVT-2----20/40

ICG

After-IVT-3----20/32

FA

d

5th month

After- IVT--4---20/25

e

1st year

EXAM--6---20/25

Due to the discordant course of morphological changes and symptoms, treatment was guided by detailed analysis and comparison of the various signs.

The clinical course and response to treatment can be followed in terms of the usual criteria of intraretinal fluid but also alterations of the neurosensory retina and other reactive signs (bright hyper-reflective spots and intraretinal dense zones). These various features are more clearly visible on enlarged views.

8Spectralis* SD-OCT allowed long-term follow-up of the effects of neovascularization on the outer retinal layers

(Figure 27a-d).

Due to the persistence of limited changes on OCT (small amount of SRF, predominantly shifting) with almost normal visual acuity and no metamorphopsias, close monitoring was performed without injections.

After one year of follow-up

▬Symptoms remained minimal with normal visual acuity.

▬However, detachment of the RPE from Bruch’s membrane remained clearly visible with a wavy appearance composed of several fluid pockets, but it remained relatively flat with only a small amount of intraretinal fluid. Several signs of fibrosis and early organization, as well as multiple irregularities of the RPE, were observed (Figure 27).

In this Patient

The course initially appeared to be stabilized for more than a year, and any further treatment was not justified, apart from a “maintenance” injection. However, persistence of SRF and alterations of the outer retinal layers required long-term

follow-up. The patient experienced a recurrence

at the end of the second year, with loss of VA and

metamorphopsias without obvious angiographic changes.

▬The outer nuclear layer was constantly visible, but thinned, as if displaced by the dome of the PED, with localized areas of increased density (Figure 27a), (circle).

▬The external limiting membrane was clearly visible in the central zone.

▬The IS/OS interface between outer segments and inner segments was markedly altered in the zone of the SRF, with the presence of several bright hyper-reflec- tive spots and irregularities of the outer segments (Figure 27a) (arrow).

Four months later

The situation appeared to be stable with no new symptoms and very little alteration of the angiographic or SDOCT signs (Figure 27b). However, another intravitreous injection of anti-VEGF was administered due to persistence of a marked shifting SRF and the presence of active lesions in the fellow eye.

Subsequent examinations showed a satisfactory appearance that remained stable for the following three months (no symptoms, stability of fundus, and OCT images) (Figure 27c).

At the end of the second year

The patient experienced a symptomatic recurrence over several days with loss of visual acuity and changes of the outer retinal layers and RPE (Figure 27d). This recurrence was treated by another IVT injection that was immediately effective, providing functional recovery.

However, at the time of the recurrence, detailed analysis of OCT showed almost complete loss of the outer nuclear layer in the central zone with the appearance of hyper-reflective material anterior to the RPE and an increased number of bright hyper-reflective spots. The PED cavity was invaded by hyper-reflective material,

suggestive of progressive fibrosis (Figure 27d).

Immediate treatment led to rapid resolution of all of these signs, and this recurrence justified observation for at least another year.

b

1 year and 4 months

Outer Nuclear layer

SRD

PED

c

1 st year and half

Altered outer segments

SRD

PED

d

Clinical Signs

A 79-year-old man presented for the first time with moderate, progressive, unilateral vision loss in his right eye, which was associated with metamorphopsias.

VA RE: 20/50 - VA LE: 20/25.

Biomicroscopic examination showed an oval-shaped, relatively flat, macular and temporal elevation with a grayish rim and two small poorly visible juxtafoveal hemorrhages. Several soft drusen were seen at the edge of the lesion with no lipid exudates.

Autofluorescence showed poorly-demarcated slight hy-

8per-fluorescence in the temporal part of the macula, sparing the central zone and xanthophyll pigment.

Fluorescein Angiography

▬In the superior half of the lesion, a juxtafoveal and subfoveal zone of early, intense, and well-delineated hyper-fluorescence suggested classic CNV with in-

tense and rapid fluorescein leakage and very large cysts at the late phase.

▬In the inferior half of the lesion, an area of slightly heterogeneous, gradually staining hyper-fluorescence with several pinpoint leaks and late and moderate fluorescein leakage (Figure 31).

SLO-ICG Angiography

a)Early phase: narrow juxtafoveal and superior temporal vessels with rapid circulation. This neovascular membrane was drained by a larger vessel which coursed towards the inferior macular sector.

b)Late phase: extensive, oval-shaped, well-demarcated, hyper-fluorescent lesion. The inferior and superior parts presented different structures (Figure 31).

Suggested Diagnosis:

Mixed juxtafoveal and subfoveal classic and occult CNV.

On the horizontal section in the center the fovea

Stratus* TD-OCT showed irregular thinning without elevation of the RPE in the juxtafoveal and temporal zones.

Anterior to the RPE

▬Zone of hyper-reflectivity extending as far as the fovea (arrows) with slight shadowing.

▬Beyond, intraretinal cysts with markedly increased retinal thickness (Figure 31).

Spectralis* SD-OCT

▬The same signs were clearly visible, with intraretinal fluid, cysts, and numerous bright hyper-reflective spots. The limits of the juxtafoveal and subfoveal lesion were more clearly defined.

▬The external limiting membrane and IS/OS interface were altered over the zone of hyper-reflective CNV.

▬The outer nuclear layer was thinned and invaded by a hyper-reflective zone (Figure 31).

On the vertical section through the inferior lesion

Stratus* TD-OCT

▬The moderately reflective vascularized PED was well demonstrated from below to upwards, and

▬Hyper-reflectivity anterior to the RPE and cysts corresponding to classic CNV (Figure 32).

Spectralis* SD-OCT

▬The appearance on SD-OCT was identical, but SDOCT provided good visibility of the vascularized PED and subfoveal classic CNV.

▬A small SRF accumulation was demonstrated all around the lesion with numerous bright hyper-reflec- tive spots, as well as alteration of the outer segments

and outer nuclear layer (Figure 32).

Note the persistence of foveal vitreoretinal adhesions.

Diagnosis

OCT confirmed the presence of a mixed lesion with:

▬An extensive subfoveal vascularized PED with a moderately reflective cavity, and

▬An area of active classic CNV with alteration of outer layers, intraretinal fluid, and temporal, subfoveal, and juxtafoveal cysts.

These findings confirmed and refined the diagnosis suggested by fluorescein angiography (classic CNV) and ICG angiography (vascularized PED and draining vessels), justifying immediate anti-VEGF therapy.

Classic CNV