Integration Patterns of Cryopreserved Amniotic Membranes into the Human Cornea
Received 9 October 2005; accepted 27 March 2006.
Purpose
Because of the wide spectrum of indications and the different techniques used, amniotic membrane transplantation (AMT) may result in many variants of wound healing. Our aim was to investigate and classify the integration patterns of amniotic membrane (AM) into the human anterior cornea following AMT.
Design
Retrospective, noncomparative, nonconsecutive, interventional case series.
Participants
Twenty-four eyes of 24 patients (age, 64.9±13.6 years).
Methods
Eyes underwent penetrating keratoplasty 26.1±25.1 weeks (range, 0.3–79) after transplantation of cryopreserved human AM. Histopathologic and ultrastructural examinations were performed on the excised corneal buttons.
Main Outcome Measures
Patterns were classified according to the topographic relationship between AM and corneal epithelium. The respective thicknesses of the corneal epithelium and AM layer(s) were measured.
Results
Integrated AM was found in 18 of 24 corneas up to 79 weeks after transplantation. Amniotic epithelium was present in only 4 of 24 cases with intracellular signs of degeneration. Amniotic membrane stroma was integrated in 4 patterns: (1) intraepithelial (4 eyes); (2) subepithelial (11 eyes); (3) intrastromal, with various grades of retraction (4 eyes); and (4) superficial localization—AM present on the corneal surface (disintegration) (7 eyes). More than 1 pattern was found in 4 specimens. The thickness of corneal epithelium varied between 13.4 and 102.6 μm, and the thickness of AM between 9.0 and 162.5 μm.
Conclusions
Amniotic membrane can integrate into the host corneal tissue after AMT in intraepithelial, subepithelial, or intrastromal patterns, or may be localized on the corneal surface. The thicknesses of corneal epithelium and AM are extremely variable. The morphology of the individual pattern seems to depend on the ocular surface disorder and AMT technique. Classification of AM integration patterns may assist in selecting the most suitable transplantation technique for specific surface disorders.
11st Department of Ophthalmology, Semmelweis University, Budapest, Hungary.
2Department of Ophthalmology, Friedrich Alexander University of Erlangen-Nürnberg, Erlangen, Germany.
3Department of Gynaecology and Obstetrics, Friedrich Alexander University of Erlangen-Nürnberg, Erlangen, Germany.
Correspondence to Miklós Resch, MD, 1st Department of Ophthalmology, Semmelweis University, Tömö utca 25-29, H-1083 Budapest, Hungary.
Manuscript no. 2005-964.
The authors have no commercial or proprietary interest in the products or companies mentioned in the article.
Supported by the Hungarian Ministry of Education, Budapest, Hungary (“Eötvös” scholarship no.: 63/2004).
ABSTRACT