Acquired macular disorders

Age-related macular degeneration


  • Definition: degeneration affecting the macula; characterized by drusen and RPE changes, and sometimes CNV.

  • Classification: non-exudative (‘dry’)—most common, and exudative (‘wet’); the latter is associated with more rapid progression to advanced sight loss.

  • Importance: most common cause of irreversible visual loss in industrialized countries; advanced age-related macular degeneration (AMD) in one eye confers a 50% chance of advanced AMD in the fellow eye within 5 years.

  • Risk factors: (a) age, (b) race (higher in Caucasians), (c) family history (several genes implicated), (d) smoking (doubles risk), (e) dietary factors (e.g. high fat intake), and (f) others (cataract surgery, blue iris colour, sunlight).


  • Pathogenesis: extracellular deposits at the interface between the RPE and Bruch membrane, derived from immune-mediated and metabolic processes in the RPE.

  • ‘Hard’ drusen: well-defined and small (less than half a retinal vein width; Fig. 14.1 ); their presence in isolation carries little risk of visual loss.

    Fig 14.1

  • ‘Soft’ drusen: less distinct and larger than hard drusen; numerous large soft drusen ( Fig. 14.2 ) are associated with a high risk of visual loss, including progression to CNV.

    Fig 14.2

  • ‘Drusenoid RPE detachment’: caused by coalesce of soft drusen resulting in a localized elevation of the RPE, a ‘drusenoid RPE detachment’ ( Fig. 14.3 ).

    Fig 14.3

Prophylactic antioxidant supplementation in AMD

The Age-Related Eye Disease Study (AREDS) established that taking high-dose antioxidant vitamins and minerals on a regular basis can decrease the risk of AMD progression.

  • Indications: those aged older than 55 years with one or more of the following high-risk characteristics (extensive intermediate-sized drusen, at least one druse over 125 µm, geographic atrophy, advanced AMD in one eye); treatment confers a reduction in risk of up to 25% at 5 years.

  • AREDS regimen: vitamins C and E, beta-carotene, zinc, and copper; possible adverse effects include an increased risk of lung cancer in smokers.

  • Other measures: (a) macular xanthophylls (lutein and zeaxanthin) and omega-3 fatty acids, (b) adequate leafy green vegetable intake; (c) cessation of smoking and avoidance of excessive sunlight should also be considered.

Non-exudative AMD

  • Diagnosis

    • Presentation: gradual impairment of central vision over months or years in one or both eyes.

    • Signs: (a) numerous intermediate–large soft drusen, (b) focal RPE changes, and (c) areas of chorioretinal atrophy ( Fig. 14.4 ).

      Fig 14.4

    • Course: enlargement of atrophic areas to give ‘geographical atrophy’ ( Fig. 14.5 ) with disappearance of pre-existing drusen.

      Fig 14.5

    • FA: window defect if the choriocapillaris is still intact; exposed sclera may exhibit late staining.

  • Treatment: prophylactic antioxidant supplementation; experimental surgical options (e.g. intraocular telescope implantation, retinal translocation, implantable photosensitive chip).

Retinal pigment epithelial detachment

  • Pathogenesis: separation of the RPE from Bruch’s membrane caused by disruption of the physiological forces maintaining adhesion.

  • Diagnosis

    • Serous retinal pigment epithelial detaclment (PED): orange dome-shaped elevation with sharply delineated edges ( Fig. 14.6a ); subretinal blood or lipid and irregularly distributed fluid are suggestive of underlying CNV.

      Fig 14.6

    • Imaging of serous PED: (a) FA shows a well-demarcated oval area of hyperfluorescence increasing in intensity but not area—‘pooling’—in which a notch may indicate CNV ( Fig. 14.6b ), (b) ICGA shows an oval area of hypofluorescence and a faint ring of surrounding hyperfluorescence ( Fig. 14.6c ), and (c) OCT shows separation of the RPE from Bruch’s membrane by an optically empty area ( Fig. 14.6d ).

    • Course of serous PED: (a) gradually increasing atrophy and an eventual VA of 6/60 or less; (b) spontaneous resolution can occur, sometimes with visual improvement but often leaving geographic atrophy; and (c) rapid visual loss is typical of associated CNV (over 30%) or RPE tear formation (see below).

    • Fibrovascular PED: (a) a form of ‘occult’ CNV, much more irregular in outline and elevation than serous PED; (b) FA shows markedly irregular granular or ‘stippled’ hyperfluorescence, with uneven filling of the PED, leakage, and late staining; (c) OCT shows an optically denser lesion than serous PED.

    • ‘Drusenoid’ PED: (a) shallowly elevated pale area with irregular scalloped edges; (b) FA shows diffuse hyperfluorescence, and (c) OCT shows homogeneous hyperreflectivity.

    • Haemorrhagic PED: virtually all eyes have underlying CNV or polypoidal choroidal vasculopathy (see below); (a) presentation is with sudden impairment of central vision, and prognosis is poor, (b) a dark red dome-shaped lesion is seen on examination, and (c) FA shows dense masking but with overlying vessels visible.

  • Treatment

    • Serous PED: observation may be appropriate in eyes without CNV, especially in younger patients. Options for CNV are (a) intravitreal anti-VEGF agents, (b) PDT, and (c) intravitreal triamcinolone, often in combination.

    • Fibrovascular PED: as for serous PED with CNV.

    • Drusenoid PED: observation in most cases.

    • Haemorrhagic PED: see below for management of polypoidal choroidal vasculopathy (PCV) and small CNV.

Retinal pigment epithelial tear

  • Pathogenesis: tearing at the junction of attached and detached RPE, either spontaneously or after interventions such as laser or intravitreal injection.

  • Diagnosis

    • Presentation: sudden central visual loss.

    • Signs: crescent-shaped pale area of RPE dehiscence, next to a darker area corresponding to the retracted and folded flap ( Fig. 14.7a ).

      Fig 14.7

    • FA: late phase shows hypofluorescence over the flap due to the thickened folded RPE, with a linear border and adjacent hyperfluorescence where the RPE is absent ( Fig. 14.7b ).

    • OCT: hyperreflectivity adjacent to the folded RPE ( Fig. 14.7c ).

    • Prognosis: poor in subfoveal tears.

  • Treatment: unproven modalities such as RPE translocation.

Exudative AMD

Jul 11, 2019 | Posted by in OPHTHALMOLOGY | Comments Off on Acquired macular disorders
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