Epiretinal Membrane- An Overview

What Is Epiretinal Membrane?

An epiretinal membrane, also known as an ERM, is a condition that occurs when a covering of fibrous cellular tissue that is completely clear, transparent, and extremely thin forms on the outermost layer of the retina. Vision might become hazy or distorted due to this disorder, caused by damage to the macula (the ocular region responsible for processing visual information immediately in front of the individual (central vision).

What Are the Causes of the Condition?

In many instances, the etiology of epiretinal membranes is unknown. This disorder is referred to as idiopathic ERM. Epiretinal membranes are linked with other retinal conditions less frequently. Examples of such conditions include:

• Retinopathy (retinal damage from diabetes).

• Inflammation of the eye.

• Trauma.

• Ophthalmic surgery or eye surgery.

• Eye tumors.

• Reticular fissures (small openings that typically result from some breaking or splitting).

• Retinal detachment or separation.

Glial cells (cells of the central nervous system that are not neurons) may migrate to non-native sites in several instances when the outermost layer of the retina is compromised or ruptures. They initiate proliferation and develop into a layer that spans the retina's external layer.

What Are the Symptoms?

As it forms, the membrane may assume various forms and appearances. These variations can result in a wide variety of symptoms. Fortunately, a large number of individuals do not exhibit any symptoms. In other situations, the membrane may become more rigid. This tightening can cause the retina to stretch and distort vision. These visual difficulties may deteriorate over time.

• Metamorphopsia is the most typical distortion. This occurs when straight-looking objects appear to be curved or undulating. This is easier to notice if one covers the healthy eye and only gazes through the affected eye.

Other symptoms consist of:

• Double vision.

• Sensitivity to light.

• Optical illusions are when objects appear a certain size than they are.

What Are the Types?

• Grade 0: Cellophane maculopathy, also known as maculopathy (a retinal illness), is distinguished by translucent membranes and the absence of any retinal deformation or obscuration of the underlying arteries. There may be an irregular reflex, a slight shine, or a sparkle, but there will not be a clear edge.

• Grade 1: Crinkled cellophane maculopathy is a condition that causes an irregular wrinkling of the inner retina; nonetheless, the underlying arteries are still visible. They result in enhanced vascular fragility, observed as a pulling inward of peripapillary vessels towards an epicenter (focal point).

• Grade 2: Macular pucker (scar tissue has grown on the eye's macula, which is located in the center of the retina, the light-sensitive tissue of the eyes) with opaque membranes covering underlying vessels, noticeable retinal deformation, and circumferential vessels are closer together, frequently resulting in foveal ectopia (an improper anatomic location is a small, central depression formed of closely packed cones positioned in the retina's macula.), heterotopia (abnormal movement of a body part or organ), and shallow detachment of the retina.

Additional findings that could be present include cotton-wool patches, tiny intraretinal hemorrhages, and macular edema (when blood vessels burst into the macula, a portion of the retina, macular edema results). The thicker membranes, which may also be pigmented at times, are frequently observed in patients who have undergone surgery for retinal detachment, as well as those who have suffered significant trauma or disorders that cause extreme inflammation.

What Is the Treatment Method?

Medical Treatment

• Before treating the condition, the cause should be identified. Examine the patient carefully to rule out various pathologic/tissue disorders that may resemble a membrane, as surgery for the epiretinal membrane is rarely urgent.

• In primary care optometry and ophthalmology, OCT-detected asymptomatic epiretinal membranes are often recommended for investigation. Thus, preoperative patient screening and counseling are essential to identify surgical candidates and set postoperative expectations.

• For asymptomatic patients, surgery is a difficult choice. An earlier intervention improved recovery and visual acuity. Therefore, surgery postponements are safe clinically. They also advised monitoring non-tractional/movement of epiretinal membranes if the patient is not a surgical candidate.

Vitrectomy: Vitrectomy, an eye surgery procedure used to address numerous issues, is for its effectiveness in cases during epiretinal membrane peeling.

• A vitrectomy treatment helps keep the eye from contracting and pulling on the macula. Removing the sclera is also thought to make removing the membrane safer.

• Vitectomy's main drawbacks are cataracts (a region of opacity within the eye's lens) and iatrogenic (a medical examination or treatment-induced sickness.) retinal fractures. Vitrectomy patients have a 3-fold higher rate of serious cataract development at six months.

• In some circumstances, surgeons have avoided vitrectomy and performed no-infusion/no-vitrectomy membrane peelings since cataract formation reduces membrane peeling efficiency.

• Intravitreal steroids like Triamcinolone or Dexamethasone are used to speed visual recovery and improve surgical outcomes.

Peeling Epiretinal Membrane

• The membrane's outside edge is identified, and with fine forceps, they gently pull the membrane off the retinal surface once the membrane's edge is seen.

• By raising the membrane longitudinally, tears and retinal strain are prevented. This is an easy technique to perform if the membrane edge is visible.

ILM Peeling

• Using essential dyes and peeling the ILM with vital stains like ICG and Trypan blue dye helps peel ILM and epiretinal membranes. The intravitreal revealing chemical selectively stains the ILM. Dyes that stain the ILM may minimize recurrence and symptoms by highlighting epiretinal membrane foci.

• The vision will be unaffected. Non-ILM peeling individuals had faster healing and fewer absolute microscotomas in the center.

Treating Retinal Breaks

• The surgeon must inspect the retina for cracks after removing the membrane.

• Missed breaks can cause the retina to detach, rendering all membrane removal maneuvers useless.

• Indirect ophthalmoscopy and scleral depression in the front retina should detect peripheral breaks.

• Laser and cryo-retinopexy (the retina can be sealed to the eye wall using freezing temperatures) can fix breaks without subretinal fluid (fluid located beneath the retina).

• Subretinal fluid (fluid located beneath the retina) requires air drainage, and retinopexy is the correction of uncomplicated retinal detachments, including gas tamponade (the area formed after the gel that covers the vitreous is filled with specific gasses).

Conclusion

Especially in the elderly, epiretinal membranes are prevalent. ERM patients with impaired vision or metamorphopsia could benefit from vitrectomy following ERM peeling. Usually, vitrectomy with membrane peeling relieves symptoms; however, it can cause cataracts, retinal breaks/detachments, and ERM recurrence, including macular holes. Selecting surgical candidates based on prognostic criteria reduces complications and improves results. Clinical factors associated with improved postoperative VA include early age, baseline pseudophakia, and shorter symptom duration. To aid decision-making, physicians should use imaging tests, including OCT, IVFA, and FA. Through proper optimization and patient selection, epiretinal membrane removal is the most effective treatment for this severe condition.

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