Epiretinal Membrane
An avascular fibrocellular membrane that proliferates on the inner surface of the
retina and produces visual impairment
Causes:
Idiopathic ERMs is the most common presentation.
Secondary ERMs: retinal vascular diseases including diabetic retinopathy, retinal vein occlusion, ocular inflammatory disease, trauma, intraocular surgery, intraocular tumors, and retinal tear or detachment.
Symptoms: Gradual painless loss of vision, Metamorphopsia, Micropsia
Pathology: Fibrous proliferative membrane like structure consisting of cells interspersed with an extracellular matrix.
Thin sheen like membrane to a thick opaque membrane, associated with vascular tortuosity, straightening and dragging of vessel toward the fovea.
Associated intraretinal hemorrhage, cystic changes in macula, cotton wool spots, macular edema, macular hole or pseudohole.
Gass classification of ERM :
Grade 0 – Cellophane maculopathy
● Completely translucent membrane barely visible clinically. There is no foveal distortion and retinal traction
Grade 1 – Crippled cellophane maculopathy
● Contraction of ERM
● Membrane causes an irregular wrinkling of inner retinal surface.
● If wrinkling is severe enough, para macular vessels may be pulled towards the fovea
in a corkscrew formation (seen on FFA)
Grade 2 – Macular pucker
● Membrane is thick and opaque.
● Full thickness puckering of macula may be present along with edema, small
hemorrhages, cotton wool spots and sometimes localized RD
● Severe visual loss
Cause of vision loss in ERM:
● Contraction of ERM causes elevation of macula
● Retinal distortion and traction
● Macular edema
Investigations :
● Amsler grid
● FFA - can show retinal vascular tortuosity, straightening and leakage, as well as
CME, also helps in excluding the other retinal pathologies that may cause ERM formation
● OCT- To see CME,VMT,Localizing the edge and thickest part of ERM and to
differentiate lamellar macular hole from pseudohole
● Multifocal ERG
Management :
● ERM removal with/without ILM peeling