Persistent Epithelial Defects (PEDs)

Common diagnoses resulting in or associated with corneal defects include:

PEDs

Superficial Punctate Keratitis

Neurotrophic  Keratitis

Anterior Basement Membrane Dystrophy

Pterygium

PEDs are corneal epithelial defects that fail to heal within 2 weeks and arise from diverse etiologies¹

Category	Etiologies of PEDs
Surgical	Incisional or laser-based ocular surgeries Cataract surgery Pterygium removal surgery Laser-assisted in situ keratomileusis (LASIK) Penetrating or lamellar keratoplasty Neurosurgeries causing damage to the trigeminal ganglion
Injury	Exogenous injury Chemical or thermal burns Ultraviolet light injury Exposure keratopathy Prolonged overuse of contact lenses External agents Viral infection (eg, herpetic keratitis) Drugs (eg, Stevens- Johnson syndrome)
Autoimmune	Sjögren syndrome Ocular cicatricial pemphigoid Ectodermal dysplasia
Allergic	Vernal keratoconjunctivitis Atopic keratoconjunctivitis
Other	Vitamin A deficiency Severe dry eye disease Corneal dystrophies

PEDs share common pathophysiological drivers¹:

1. Tear disorder (dry eye) 

Inadequate tear film leads to reduced lubrication and excessive friction between the eyelid and the cornea, causing mechanical and inflammatory damage

2. Limbal stem cell deficiency

Disruption of the limbal stem cell niche reduces the regenerative capacity of epithelial cells

3. Inflammation 

Elevated proinflammatory mediators  (eg, IL-1β, TNF, IL-6, IL-8, matrix metalloproteinases) contribute to extracellular matrix (ECM) degradation and epithelial cell loss

4. Neurotrophic keratopathy

Alterations in corneal nerves lead to impaired sensory and trophic function, resulting in breakdown of the corneal epithelium

IL-1β, interleukin-1β; IL-6, interleukin-6; IL-8, interleukin-8; TNF, tumor necrosis factor.

Serious wounds require intervention beyond ocular surface lubrication and discontinuation of preservative-containing medications¹

Human AMT-derived allografts

The gold-standard physical barrier for ocular wound repair^1,2

How AMT helps heal ophthalmic wounds

Acts as a physical barrier, protecting the eye against mechanical trauma from lid closure and preventing surface desiccation by maintaining a hydrated microenvironment¹

Enriched with growth factors and structural proteins that promote corneal healing²

Serves as a substrate for adhesion, migration, and proliferation of corneal epithelial cells and limbal stem cells when used as a graft to treat corneal pathologies¹

Only DBM offers all the benefits of AMTs, without donor cell debris, while preserving ECM functionality and triggering an efficient host cell–mediated response^3,4

AMT, amniotic membrane tissue.

DBM represents an advance over cryopreserved and conventional dehydrated AMTs. The decellularization process:

Removes donor cell debris and proinflammatory chorion to minimize immune responses⁴

Preserves the matrix scaffold and ECM protein production⁴

Adheres efficiently to reduce slippage and allow for glueless, sutureless surgery^5,6

References: 1. Thia ZZ, Ho YT, Shih KC, Tong L. New developments in the management of persistent corneal epithelial defects. Surv Ophthalmol. 2023;68(6):1093-1114. 2. Tehrani FD, Firouzeh A, Shabani I, Shabani A. A review on modifications of amniotic membrane for biomedical applications. Front Bioeng Biotechnol. 2021;8:1-25. 3. BIOVANCE 3L Ocular. Package insert. 4. Mao Y, Protzman NM, John N, et al. An in vitro comparison of human corneal epithelial cell activity and inflammatory response on differently designed ocular amniotic membranes and a clinical case study. J Biomed Mater Res B Appl Biomater. 2023;111(3):684-700. 5. Linsey K. Use of an eyelid pressure patch concomitantly with a decellularized dehydrated amniotic membrane for ocular surface disease management. Ophthalmol Ther. 2025;14(3):573-584. 6. Rivera-Morales P, Barnard L, Linderman W, Gill M, Diaz V. Surgical time and postoperative symptoms study in pterygium excision and amniotic membrane graft using Celularity triple layer dehydrated amniotic membrane. Clin Ophthalmol. 2023;17:1967-1974.