Overview
Amniotic membrane (AM) has become an established adjunctive therapy in the management of ocular surface disease and corneal injury. For optometrists and ophthalmologists, its value lies not only in its role as a biologic bandage, but also in its ability to influence the wound-healing environment at the ocular surface. Rather than acting through a single pathway, AM supports healing through a combination of anti-inflammatory, anti-scarring, epithelial-supportive, and protective effects.
Understanding these mechanisms can help clinicians determine when AM may be appropriate, how it complements other therapies, and what outcomes to monitor during follow-up.
What is ocular amniotic membrane?
Amniotic membrane is derived from the innermost layer of the placenta. When prepared for ophthalmic use, it is processed for clinical application while retaining structural and biologically active components that may support tissue repair. Available forms include cryopreserved and dehydrated preparations, as well as sutured and self-retained devices.
From a biologic standpoint, AM consists of a basement membrane and an avascular stromal matrix. These layers contain extracellular matrix proteins, growth factors, and regulatory molecules that help create a favorable microenvironment for ocular surface healing. Although processing methods differ among products, the therapeutic concept is similar: AM serves as a temporary matrix and protective covering that can modulate the ocular surface response to injury.
Promotion of epithelial healing
One of the best-recognized actions of AM is support of corneal and conjunctival epithelialization. The basement membrane of AM resembles native ocular surface basement membrane in ways that can facilitate epithelial cell migration, adhesion, and differentiation. This makes it useful in clinical scenarios where epithelial recovery is delayed or unstable.
In practical terms, AM may help:
provide a scaffold for epithelial cell migration
support epithelial adhesion to the healing surface
reduce friction from blinking during re-epithelialization
protect exposed nerve endings and sensitive tissue while the surface repairs
These effects are relevant in persistent epithelial defects, neurotrophic keratopathy, postsurgical surface compromise, chemical injury, and severe dry eye-associated epitheliopathy. By stabilizing the local environment, AM can help move the ocular surface from a chronic injury state toward more orderly repair.
Anti-inflammatory effects
Inflammation is a central driver of many ocular surface disorders, including dry eye disease, keratitis, postoperative surface disease, and toxic or mechanical epithelial injury. AM is thought to help by reducing excessive inflammation at the site of damage.
Its stromal matrix contains molecules that can modulate inflammatory signaling and reduce infiltration or persistence of inflammatory cells. AM has also been associated with downregulation of pro-inflammatory cytokine activity in the healing environment. Clinically, this matters because persistent inflammation can disrupt epithelial integrity, worsen patient discomfort, and perpetuate a cycle of surface breakdown.
The anti-inflammatory effect of AM should be viewed as complementary to, not necessarily a replacement for, other anti-inflammatory strategies such as preservative minimization, topical corticosteroids when appropriate, immunomodulatory therapy, lid disease management, or treatment of exposure and lagophthalmos. In many patients, AM is most effective when used as part of a broader ocular surface treatment plan.
Anti-scarring and anti-fibrotic activity
A major goal in ocular surface healing is restoration of a functional, transparent surface with minimal fibrosis. AM has been shown to influence pathways involved in fibroblast activation and scarring. By modulating transforming growth factor-beta-related signaling and related wound-healing cascades, AM may reduce myofibroblast differentiation and excessive extracellular matrix deposition.
This anti-fibrotic effect is clinically relevant because uncontrolled scarring can contribute to irregularity, symblepharon formation, reduced mobility of the ocular surface, and visual compromise. In the cornea, limiting stromal haze and fibrosis may help preserve optical quality, although final outcomes depend heavily on the underlying disease severity and depth of injury.
For this reason, AM may be considered in conditions where inflammation and surface damage create a high risk of cicatricial healing, including chemical burns, postinfectious surface injury after the active infection has been addressed, and selected postoperative complications.
Protection of the ocular surface microenvironment
In addition to its biochemical effects, AM provides mechanical protection. It can function as a biologic dressing that covers damaged epithelium, reduces eyelid friction, and helps maintain a more stable surface environment. This barrier function can be especially beneficial in painful surface disorders or when repeated blinking disrupts epithelial recovery.
AM may also contribute to hydration retention at the ocular surface and help shield the cornea from ongoing external insult. In this sense, it works somewhat differently from a standard bandage contact lens. While both may protect the surface, AM offers a biologically active matrix rather than only passive coverage.
For clinicians, this distinction is important when managing patients whose healing has stalled despite lubrication, punctal occlusion, medication adjustment, or contact lens bandaging.
Effects on pain and corneal nerves
Pain relief after AM placement is commonly observed in clinical practice, especially in eyes with epithelial defects or severe surface inflammation. This likely results from several overlapping mechanisms: coverage of exposed nociceptors, reduction in friction, and dampening of inflammatory activity.
There is also interest in the relationship between AM and corneal nerve recovery, particularly in neurotrophic disease and postprocedural surface damage. While AM may help create conditions favorable for nerve-related surface recovery, clinicians should avoid oversimplifying this effect. Nerve regeneration and restoration of corneal sensation depend on the underlying cause, severity, and concomitant management.
Clinical use considerations
AM is typically considered when the ocular surface is not healing adequately with conventional therapy or when the severity of disease warrants a more active biologic approach. Common indications include persistent epithelial defects, neurotrophic keratopathy, severe keratitis, chemical or thermal injury, recurrent corneal erosion, and significant postoperative or exposure-related surface compromise.
Successful use depends on addressing the drivers of disease at the same time. Clinicians should evaluate for factors such as limbal stem cell deficiency, exposure, incomplete blink, medication toxicity, eyelid abnormalities, infection, autoimmune disease, and inadequate tear support. AM can assist healing, but it does not eliminate the need to correct ongoing insult.
Follow-up should assess membrane position or dissolution, epithelial closure, symptom response, stromal haze, inflammation, and signs of infection or progression. Patient counseling is also important, particularly regarding temporary blur, foreign body sensation, and the need for concurrent therapy.
Conclusion
Amniotic membrane therapy supports ocular surface healing through multiple mechanisms: it promotes epithelialization, modulates inflammation, reduces fibrotic healing, and protects the damaged surface during recovery. For eye-care clinicians, its greatest utility is often in difficult or nonhealing cases where the ocular surface needs both biologic support and mechanical protection.
Used thoughtfully, AM can be a valuable part of a comprehensive ocular surface strategy. Patient selection, timing of intervention, and treatment of underlying disease remain central to achieving the best clinical outcome.
Educational disclaimer: This article is for clinician education only and is not a substitute for independent clinical judgment, product labeling, or individualized patient care decisions.