- Published on
Ophthalmology – Epiretinal Membranes (ERM)
Epiretinal membranes (ERM), also known as macular pucker, cellophane maculopathy, or surface wrinkling retinopathy, are thin fibrocellular layers that form on the inner surface of the retina, particularly over the macula. While many cases are mild and asymptomatic, ERMs can distort the retinal architecture, leading to blurred vision and metamorphopsia (distorted vision). They are commonly associated with posterior vitreous detachment (PVD) and may coexist with vitreomacular traction.
ERM is primarily a disease of the elderly population, with prevalence increasing significantly with age. It is found in about 2% of individuals at age 50, rising to 20% by age 75. Although bilateral in 20–30% of cases, it is often asymmetric. Risk factors include female gender, aging, prior ocular surgery or trauma, diabetes, retinal vascular disease, intraocular inflammation, and vitreous hemorrhage. Pediatric cases are rare and usually secondary to other ocular abnormalities.
The pathophysiology involves abnormal proliferation of glial cells (including Müller cells, astrocytes, fibrocytes, and myofibroblasts) on the retinal surface. These cells often migrate after a posterior vitreous detachment, although they may appear earlier. Over time, these cells can acquire contractile properties, exerting traction on the retina and leading to wrinkling, distortion, and reduced visual acuity.
ERM can be classified as idiopathic (primary) or secondary. Idiopathic ERMs occur without an identifiable cause, while secondary ERMs develop in association with retinal vascular diseases, inflammation, trauma, or prior surgery.
Clinically, many patients are asymptomatic, especially in early stages. Symptomatic patients may report gradual vision loss, distortion of straight lines (metamorphopsia), difficulty reading, or central blurring. Occasionally, patients may experience diplopia or photopsias.
On examination, subtle ERMs may appear as a shiny, glistening reflex on the macula, while more advanced cases show retinal folds (striae), vessel tortuosity, and macular thickening. In some cases, cystoid macular edema (CME) or small hemorrhages may be present due to traction.
Diagnosis is primarily clinical but is best confirmed with imaging. Optical coherence tomography (OCT) is the gold standard and demonstrates retinal surface wrinkling, thickening, and possible cystoid changes. OCT also helps assess prognosis, as disruption of photoreceptor layers or significant edema correlates with poorer outcomes. Fluorescein angiography (FA) may be used to evaluate for underlying vascular disease or macular leakage. Amsler grid testing is useful for monitoring visual distortion.
The differential diagnosis includes proliferative diabetic retinopathy, retinal vein occlusion-related fibrosis, and incomplete posterior vitreous detachment with adherent posterior hyaloid.
Management depends on symptom severity. Asymptomatic patients require no treatment and can be observed with periodic follow-up. For patients with mild edema, topical NSAIDs or steroids may be used. However, medical therapy is generally limited in effectiveness for ERM itself.
Definitive treatment is surgical, indicated in patients with significant visual symptoms or visual acuity worse than ~20/40. The procedure involves pars plana vitrectomy with membrane peeling, often including removal of the internal limiting membrane (ILM) to reduce recurrence risk. Advances in minimally invasive vitrectomy have improved recovery times and outcomes.
Follow-up includes routine monitoring and Amsler grid use, with prompt reassessment if symptoms worsen. Many ERMs remain stable for years, but progression can occur, especially after acute PVD or ocular surgery.
The prognosis is generally favorable. Asymptomatic patients maintain good vision, while 80–90% of surgical patients experience improvement of at least two Snellen lines. However, complete restoration to normal vision (20/20) is uncommon, and outcomes depend largely on preoperative visual acuity and retinal integrity.
Complications include cataract formation (most common), retinal tears or detachment, recurrent ERM, retinal phototoxicity, and rarely endophthalmitis.
Epiretinal membranes (ERM), also known as macular pucker, cellophane maculopathy, or surface wrinkling retinopathy, are thin fibrocellular layers that form on the inner surface of the retina, particularly over the macula. While many cases are mild and asymptomatic, ERMs can distort the retinal architecture, leading to blurred vision and metamorphopsia (distorted vision). They are commonly associated with posterior vitreous detachment (PVD) and may coexist with vitreomacular traction.
ERM is primarily a disease of the elderly population, with prevalence increasing significantly with age. It is found in about 2% of individuals at age 50, rising to 20% by age 75. Although bilateral in 20–30% of cases, it is often asymmetric. Risk factors include female gender, aging, prior ocular surgery or trauma, diabetes, retinal vascular disease, intraocular inflammation, and vitreous hemorrhage. Pediatric cases are rare and usually secondary to other ocular abnormalities.
The pathophysiology involves abnormal proliferation of glial cells (including Müller cells, astrocytes, fibrocytes, and myofibroblasts) on the retinal surface. These cells often migrate after a posterior vitreous detachment, although they may appear earlier. Over time, these cells can acquire contractile properties, exerting traction on the retina and leading to wrinkling, distortion, and reduced visual acuity.
ERM can be classified as idiopathic (primary) or secondary. Idiopathic ERMs occur without an identifiable cause, while secondary ERMs develop in association with retinal vascular diseases, inflammation, trauma, or prior surgery.
Clinically, many patients are asymptomatic, especially in early stages. Symptomatic patients may report gradual vision loss, distortion of straight lines (metamorphopsia), difficulty reading, or central blurring. Occasionally, patients may experience diplopia or photopsias.
On examination, subtle ERMs may appear as a shiny, glistening reflex on the macula, while more advanced cases show retinal folds (striae), vessel tortuosity, and macular thickening. In some cases, cystoid macular edema (CME) or small hemorrhages may be present due to traction.
Diagnosis is primarily clinical but is best confirmed with imaging. Optical coherence tomography (OCT) is the gold standard and demonstrates retinal surface wrinkling, thickening, and possible cystoid changes. OCT also helps assess prognosis, as disruption of photoreceptor layers or significant edema correlates with poorer outcomes. Fluorescein angiography (FA) may be used to evaluate for underlying vascular disease or macular leakage. Amsler grid testing is useful for monitoring visual distortion.
The differential diagnosis includes proliferative diabetic retinopathy, retinal vein occlusion-related fibrosis, and incomplete posterior vitreous detachment with adherent posterior hyaloid.
Management depends on symptom severity. Asymptomatic patients require no treatment and can be observed with periodic follow-up. For patients with mild edema, topical NSAIDs or steroids may be used. However, medical therapy is generally limited in effectiveness for ERM itself.
Definitive treatment is surgical, indicated in patients with significant visual symptoms or visual acuity worse than ~20/40. The procedure involves pars plana vitrectomy with membrane peeling, often including removal of the internal limiting membrane (ILM) to reduce recurrence risk. Advances in minimally invasive vitrectomy have improved recovery times and outcomes.
Follow-up includes routine monitoring and Amsler grid use, with prompt reassessment if symptoms worsen. Many ERMs remain stable for years, but progression can occur, especially after acute PVD or ocular surgery.
The prognosis is generally favorable. Asymptomatic patients maintain good vision, while 80–90% of surgical patients experience improvement of at least two Snellen lines. However, complete restoration to normal vision (20/20) is uncommon, and outcomes depend largely on preoperative visual acuity and retinal integrity.
Complications include cataract formation (most common), retinal tears or detachment, recurrent ERM, retinal phototoxicity, and rarely endophthalmitis.
0 Comments
