Ординатура / Офтальмология / Английские материалы / Moorfields Manual of Ophthalmology_Jackson_2007

4.Pale disc.

5.Peripheral retinoschisis.

6.Albinism.

7.Cone dystrophy.

8.Autoimmune phenomena.

9.Old inflammatory lesions – acute zonal occult outer retinopathy (AZOOR).

10. History of malignancy – carcinoma-associated retinopathy (CAR), melanoma-associated retinopathy (MAR).

■Consider: previous arterial occlusion; optic nerve/visual pathway disease; amblyopia; functional vision loss; transient vision loss (disc oedema, CNS ischaemia, migraine, elevated IOP).

■For children, see page 579.

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Age-related macular degeneration

Age-related Macular

Degeneration

Age-related macular degeneration (AMD) is a degenerative disorder affecting those over the age of 50 years. Features include drusen and RPE pigmentary abnormalities in the early stage, and geographic atrophy, choroidal neovascularization (CNV), pigment epithelial detachment (PED), and fibrous macular scarring in the late stages.

Early AMD

Symptoms Usually asymptomatic, but gradual central visual loss of night vision, prolonged after-images, or slight metamorphopsia may occur.

Signs Drusen of variable size and shape and macular RPE pigmentary abnormalities (hyperpigmentation or hypopigmentation) (Fig. 10.28).

Differential diagnosis Inherited dominant drusen; basal laminar-type drusen; drusen associated with choroidal nevus; other causes of retinal flecks such as Stargardt’s dystrophy; pattern dystrophy; fundus albipunctate dystrophy; mesangiocapillary glomerulonephritis type II.

Investigations Fluorescein angiography only if CNV is suspected on clinical examination and/or Amsler grid testing. Autofluorescent imaging if available.

Treatment

■Stop smoking. Data from three epidemiologic studies showed that current smokers were at higher risk of incident AMD than both past smokers and those who never smoked.

■Diet and antioxidant vitamin supplementation. Some ophthalmologists recommend a diet rich in lutein and zeaxanthin (green leafy vegetables five or more times weekly) that has been shown to increase macular pigment density, but no robust clinical trial data exist. The age-related eye disease study group showed that an antioxidant vitamin combination (500 mg vitamin C, 400 IU vitamin E, 15 mg beta-carotene, 80 mg zinc, and 2 mg copper) has a moderate protective effect to the fellow eye of patients with vision loss

in one eye from late AMD. Beta-carotene is contraindicated in smokers: there is also some concern on theoretical grounds in geographic atrophy although not all clinicians agree. Many ophthalmologists also place patients with bilateral intermediate and large drusen with no late AMD on vitamin supplementation, although the evidence is weaker.

Follow–up Regular ophthalmic review is not required, but provide an Amsler grid and instructions to return urgently should the patient develop new macular symptoms. Advise annual optometry review.

Geographic Atrophy

Symptoms In geographic atrophy (GA) there is a gradual loss of central vision or slight metamorphopsia. Extrafoveal atrophy may be asymptomatic.

Signs Sharply demarcated area(s) of GA that is pale relative to the surrounding retina, with increased visibility of underlying choroidal vessels. Intermediate or large drusen are present in most eyes surrounding the GA, unless the atrophy is very extensive (Fig. 10.29).

Differential diagnosis Stargardt’s disease, Best’s macular dystrophy, rod–cone dystrophies, Sorsby’s dystrophy, chronic central serous retinopathy, basal laminar drusen, myopic macular degeneration, and chloroquine retinopathy.

Investigations Fluorescein angiography if exudative AMD (see below) is suspected on examination or Amsler grid testing.

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Age-related macular degeneration

Fig. 10.29: Geographic macular atrophy.

Treatment See early AMD above. Arrange low-vision aids if necessary.

Follow–up Provide an Amsler grid and instructions to return urgently should they develop new macular symptoms. GA typically expands and this may reduce vision, as may the development of exudative AMD. Advise annual optometry review.

Exudative AMD

Symptoms Typically, rapid onset of visual loss, central blind spot or distortion. Uniocular, asymptomatic AMD may be picked up on routine eye testing.

Signs May appear as a greenish-grey lesion, often with sensory retinal detachment. There may be surrounding drusen, pigment change, subretinal haemorrhage and exudates. Classification is by angiography (see below).

Differential diagnosis

■CNV: other causes include myopia; angioid streaks;

multifocal choroiditis; trauma; idiopathic; inherited dystrophies (Sorsby’s).

■PED/serous detachments: other causes include central serous retinopathy; congenital optic nerve pit; macular hole with

■AMD variants: idiopathic polypoidal choroidal vasculopathy retinal angiomatous proliferation (Stage I; intraretinal neovascularization; progressing to Stage II; subretinal neovascularization; then Stage III; choroidal neovascularization with a retinal choroidal anastamosis).

Fluorescein angiography (FFA) Required to confirm the lesion type, plan treatment, and classify disease as follows.

■Classic CNV : early well defined hyperfluorescence with late

leak that obscures the boundaries (Fig. 10.30). May be 100% classic, predominantly classic (>50% of total lesion area), or minimally classic (<50%).

■Occult CNV : hyperfluorescence is less well defined than classic lesions (Fig. 10.31). The following are 2 commonly described subtypes.

1. Fibrovascular PED : an area of irregular RPE elevation that is less discrete than classic CNV in the transit phase and shows stippled hyperfluorescence in the midframes (1–2 minutes).

2. Late leakage of undetermined origin : pooling of dye and specked hyperfluorescence that occurs in the late frames.

■Serous PED : sharply demarcated area of uniform hyperfluorescence that develops rapidly under the dome of the PED and persists late with relatively sharp borders. May be associated with classic or occult membranes

(Fig. 10.32).

■Disciform scar: late staining of fibrosis, with no leak

beyond borders unless residual active membrane exists (Fig. 10.33).

Treatment See early AMD above regarding antioxidant vitamins and smoking advice. Arrange low vision aids if necessary. If uniocular, warn patients of the risk to the fellow eye (10–15% per year). Provide an Amsler grid and instructions.

■Laser

Indications for argon laser treatment depends on the angiographic characteristics and lesion location. In general, treatment is most beneficial with classic lesions and if the patient is not hypertensive. Argon laser is most effective in treating extrafoveal lesions. The more accepted treatments are as follows, but indications change and research is rapidly

RETINA MEDICAL 10 Chapter

Age-related macular degeneration

A

B

Fig. 10.30: Classic (100%) choroidal neovascular membrane (A) and early angiogram (B).

1.Extrafoveal (>200 μm from foveal centre): laser.

2.Juxtafoveal (< 200 μm from foveal centre): laser if between 100 and 200 μm from the fovea and no occult component, otherwise treat as subfoveal.

3.Subfoveal:

Age-related macular degeneration

460

A

B

Fig. 10.32: Large pigment epithelial detachment.

limbus in aphakic or pseudophakic patients, and 4 mm in phakic patients), aiming the needle towards the optic disc to avoid the lens. Use strict aseptic conditions including povidone-iodine drops and a lid speculum.

4. Follow-up : Check IOP within 30 minutes. Review 2–7 days postinjection, then at 6 weeks to consider further

Age-related macular degeneration

2. Consent: Benefit – the MARINA phase III study of Lucentis for minimally classic/occult lesions showed 5% (treated) versus 38% (sham injection) moderate vision loss (>15 letters on ETDRS chart) at 1 year, giving an NNT of 3. The ANCHOR phase III study of predominantly classic lesions showed 4% (treated) versus 36% (PDT) moderate vision loss (NNT 3.1). Risks – similar to pegaptanib.

3. Methods : Pars plana intravitreal injection (see pegaptanib) monthly for 1 year. The PIER study compared Lucentis and sham injections, both given once per month for the first 3 months, thereafter, every 3 months. Treatment provided a 16 letter benefit compared to sham, but was less effective than monthly injections.

4. Follow-up : Check IOP within 30 minutes and review monthly. Advice is similar to that for pegaptanib.

■Anecortave acetate

Administered every 6 months, in a posterior juxtascleral location using a blunt tipped curved cannula. Retaane (15 mg anecortave acetate suspension) has been approved for the treatment of subfoveal CNV with a classic component.

■Ongoing clinical trials

Other treatment options include intravitreous steroids, several novel angiostatic agents (e.g. squalamine, bevacizumab [Avastin]) and surgical procedures such as macular translocation and autologous RPE transplantation.