Cystoid macular oedema (CMO)

Definition: Thickening of macula from breakdown of blood retinal barrier leading to accumulation of intraretinal fluid at the junction of inner nuclear layer and outer plexiform layer.

Causes:

1. Metabolic – DR, radiation

2. Ischaemic – RVO, DR, HTN, vasculitis, collagen dis

3. Mechanical – VMT, ERM

4. Inflammation – uveitis, post-op

5. Hydrostatic – hypotony, venous occlusion

6. Miscellaneous – macroaneurysm, telangiectasia, CNV, choroidal haemangioma, drugs (epinephrine, betaxolol, latanoprost), RP

7. CMO like condition – XLR, nicotinic acid, OD pit, Goldmann Favre

Symptoms: loss of vision with metamorphopsia.

Investigations: OCT macula; FFA

Treatment:

1. Observe – most cases resolve especially uncomplicated cataract surgery within 6 mths.

2. Diamox – for RP

3. Topical NSAIDs – for inflammatory causes. (also to consider as prophylaxis pre op for high risk cases)

4. Topical, periocular, intravitreal or oral/IV corticosteroids – for inflammatory causes.

5. IVT anti-VEGF – for ischaemic causes.

6. Immunosuppressive drugs – for inflammatory causes.

7. Grid Laser – for ischaemic causes.

8. PPV – for mechanical causes.