Tissue Formats & Preservation Methods

The clinical profile of an amniotic membrane product is significantly influenced by its processing and preservation method. Understanding these differences helps practitioners select the optimal product for each indication.

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Cryopreserved AM

Maintained at −80°C; preserves viable cells and the full complement of growth factors and cytokines. Considered the "gold standard" for biological activity. Requires frozen storage and thawing before use. Most widely studied format in clinical literature.

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Dehydrated AM (DHACM)

Lyophilized or desiccated for room-temperature storage (up to 5 years). Highly convenient for office use. Retains matrix proteins and most growth factors; viable cells are not preserved. Multiple products available in various sizes and configurations.

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Self-Retained Ring Devices

Dehydrated AM mounted on a symblepharon ring or contact lens carrier. Applied in-office under topical anesthesia. Dissolves over 5–7 days as the ring is retained on the eye. Ideal for DED, acute SJS, and mild-to-moderate surface disease.

In-Office Self-Retained Application

Self-retained amniotic membrane devices have made AM therapy accessible outside the operating room, dramatically expanding the number of patients who can benefit. The technique is straightforward and takes approximately 5–10 minutes.

1

Patient Preparation

Instill 1–2 drops of topical anesthetic (proparacaine 0.5% or tetracaine 0.5%). A lid speculum may be used for patient comfort. No IV sedation required.

2

Device Preparation

For dehydrated ring devices: hydrate per manufacturer instructions (typically 30 seconds in sterile BSS). Confirm correct orientation — membrane surface should face the ocular surface.

3

Placement

Insert the ring under the inferior fornix first, then fold and insert under the superior fornix — similar to a scleral lens insertion technique. Confirm the membrane is flat and covering the cornea and limbal zone.

4

Post-Application Instructions

Patients typically wear the device for 5–7 days. Prescribe prophylactic antibiotic drops and lubricating drops as needed. Schedule a follow-up at device dissolution or removal.

5

Follow-Up & Repeat Treatment

Evaluate corneal staining, TBUT, and symptoms at follow-up. Many DED patients require 2–3 treatment cycles for sustained benefit. Some practices schedule quarterly maintenance treatments.

Surgical OR Application

For more complex indications — corneal ulcers, chemical burns, pterygium, ocular surface tumors — amniotic membrane is applied in the operating room and secured with sutures or fibrin glue.

Suture Fixation Technique

The gold standard for surgical AM application. Cryopreserved membrane is trimmed to fit the defect and sutured with 10-0 nylon or 8-0 vicryl, with sutures placed approximately 1.5mm apart at the graft periphery.

  • Stroma-side down for epithelial regeneration
  • Epithelium-side down for anti-inflammatory/bandage effect
  • Multilayer technique for deep ulcers or severe burns

Fibrin Glue Technique

A faster alternative to suturing, fibrin glue (e.g., Tisseel) reduces OR time and eliminates suture-related inflammation. Particularly useful for large grafts or pediatric cases where suture removal under anesthesia is a concern.

  • Apply thrombin component to bed, fibrinogen to graft underside
  • Smooth graft into position, hold 60 seconds
  • Trim excess membrane at limbus or conjunctival edge

Coding note for surgeons: Amniotic membrane transplantation is typically billed under CPT 65778 (application to cornea) or 65779 (application to conjunctiva), with additional codes depending on complexity and adjunctive procedures. Confirm payer-specific coverage with your billing team.

Expected Outcomes & Evidence Summary

Indication Primary Outcome Evidence Level
Dry Eye Disease Corneal staining reduction, improved TBUT & OSDI Level I (RCTs)
Persistent Epithelial Defects Complete healing rate 75–90% Level II–III
Chemical Burns (acute) Reduced LSCD, lower symblepharon rate Level II
Pterygium (post-excision) Recurrence 5–15% vs. 40–80% bare sclera Level I (meta-analyses)
SJS Acute Phase Reduced symblepharon, improved long-term vision Level II–III
Neurotrophic Keratitis Epithelial closure in 60–90% of cases Level II–III

Source Amniotic Membrane Products Through Blue River Medical

We carry a curated portfolio of cryopreserved, dehydrated, and self-retained amniotic membrane products. Request samples, pricing, and clinical literature support.