Cystoid Macular Edema (CME)

Cystoid Macular Edema (CME)
SYMPTOMS Decrease in central vision, Metamorphopsia
SIGNS Loss of a foveal reflex, Petaloid or honeycomb appearance at the macula due to accumulation of fluid in the outer plexiform layer/Henle’s layer, Cystic spaces that start in the outer plexiform layer/Henle’s layer with eventual involvement of the inner nuclear layer, Signs of associated conditions such as retinal vascular occlusions
Chronic cystoid macular edema will eventually cause Photoreceptor loss, Macular ischemia, Macular holes, and Sensory retinal detachments at the fovea
WORK-UP Full eye exam with dilated retinal exam, OCT analysis of the macula (signs of cystoid macular edema are best seen with an OCT), OCT-Angiography, Fluorescein Angiography, Indocyanine Green Angiography, Fundus Autofluorescence, Fundus photos, Infrared retinal imaging, Watzke-Allen test, Macular photostress test, Amsler grid
TREATMENT Give take home Amsler grid in order to monitor for change
Discontinue any medications that may be associated with cystoid macular edema such as topical prostaglandins or nicotinic acid
If cystoid macular edema is associated with Irvine-Gass syndrome, topical NSAIDs should be used (95% of cases resolve within 6 months)
If cystoid macular edema is associated with Retinitis Pigmentosa, topical dorzolamide or oral acetazolamide 500mg once a day should be used
Otherwise refer to a retinal specialist for treatment (treatment includes intravitreal anti-VEGF injections, intravitreal steroid injections, and intravitreal steroid implants)
FOLLOW-UP If observing or treating in-office, patient should be seen back in 2-4 weeks
If macula is stable following treatment by retinal specialist, patient should be seen back in 4-6 months
ADDITIONAL LAB | TESTS None unless if the patient presents with an associated uveitis, retina-vascular disease, or choroidal tumor
ETIOLOGY Occurs due to breakdown of the inner blood-retina barrier which leads to leakage of plasma (more so than exudates) from the perifoveal retinal capillaries specifically in the deep vascular complex
DIFFERENTIAL DX Diabetic macular edema, Central serous chorioretinopathy
NOTES Leakage typically occurs in the outer plexiform layer/Henle’s layer first as it is a watershed zone
Cystic spaces in the fovea region tend to be larger than the rest of the macula as there are fewer and weaker Muller cells in this area
Cystoid macular edema can be associated with the following: Uveitis especially if posterior, Retinitis Pigmentosa, Irvine-Gass Syndrome (CME typically occurs 6-10 weeks post-op), Retina-vascular disease such as central retinal vein occlusions, Choroidal neovascular membranes, Choroidal tumors, Epiretinal membranes, Vitreomacular traction, Macular holes, Medications such as prostaglandins and nicotonic acid
Cystoid Macular Edema (CME): Fluorescein angiography demonstrating leakage in a petaloid or honeycomb pattern