Comparing ProKera With Amniotic Membrane Transplantation: Indications, Outcomes, and Costs.

PURPOSE: The aim of this study was to compare the outcomes of ProKera versus amniotic membrane transplantation (AMT) in managing ocular surface disease. METHODS: This study is a retrospective case series of patients who received either ProKera or sutured AMT for ocular surface disease. Patient demographics, treatment indications, retention time, percentage healed area, changes in visual acuity, and costs to the health care system were analyzed. RESULTS: Fourteen patients were identified and analyzed for each group. The main indications for using ProKera and AMT were similar, including corneal ulcer or epithelial defect due to chemical burns, neurotropic state, or herpes zoster keratitis. The average time to dissolution or removal was 24.8 days in the ProKera group, compared with 50.1 days in the AMT group. The average percentage of healed corneal area was 59% for ProKera and 73% for AMT. There was no significant difference between the initial and the final visual acuity within groups and when comparing both groups. In our expense analysis, ProKera had a total cost of 699.00 Canadian dollars (CAD), whereas the cost of suture AMT was 1561.52 CAD. ProKera priced at 11.85 CAD for each percentage healed surface area and at 21.39 CAD for AMT. CONCLUSIONS: ProKera allowed for a faster corneal healing than sutured AMT, although its total healed area was less than the latter. Moreover, ProKera is more cost-effective than AMT, thus reducing financial burden to our health care system.

Assessment of Antimicrobial Activity of Dehydrated Amniotic Membrane in Infectious Keratitis: A Small Retrospective Case Series and In Vitro Study.

PURPOSE: To describe a small case series of infectious keratitis with poor visual outcomes after amniotic membrane (AM) placement and to prospectively evaluate whether AM demonstrates antibacterial activity in vitro against pathogens commonly isolated from infectious corneal ulcers. METHODS: A retrospective case series and in vitro study of antibacterial activity of dehydrated AM using disk diffusion and measurement of inhibitory zones for bacterial assessment and inverted microscopy analysis for Acanthamoeba sp. growth. RESULTS: Three cases of known etiology infectious keratitis are described where the clinical presentation worsened after treatment with AM. In vitro analysis of dehydrated AM, with and without a soft contact lens, demonstrated no inhibition of growth against Pseudomonas aeruginosa or Streptococcus pneumoniae. There was minimal growth inhibition of Staphylococcus aureus, although these zones of inhibition were much smaller than that surrounding the positive control. For Acanthamoeba sp., solubilized, dehydrated AM did not alter cyst density. CONCLUSIONS: In an in vitro analysis, dehydrated AM did not provide evidence for a potentially clinically meaningful antibacterial effect against organisms commonly isolated from corneal ulcers.

Dehydrated human amnion and chorion allograft versus standard of care alone in treatment of Wagner 1 diabetic foot ulcers: a trial-based health economics study.

AIMS: The aim of this health economics study was to estimate the cost-utility of an aseptically processed, dehydrated human amnion and chorion allograft (dHACA) plus standard of care (SOC) (group 1) versus SOC alone (group 2) based on a published randomized controlled trial in which patients who had an eligible Wagner 1 diabetic foot ulcer wound were randomized to either of these treatments. MATERIALS AND METHODS: A Markov microsimulation was used to project trial results out to a 1-year horizon time with a third-party payer perspective. The starting health state was an unhealed non-infected ulcer with other health states of healed ulcer, infected non-healed ulcer, cellulitis, osteomyelitis, and absorbing states of dead or amputation. All patients started with unhealed non-infected ulcers at cycle 0. Costs were incurred by patients for procedures at hospital outpatient wound care provider-based departments (PBDs) and hospitals (if complications occurred) and were calculated using time-based activity costing methods. Effectiveness units were quality-adjusted life years (QALYs) computed from literature utility values. One-way and probabilistic sensitivity analysis (PSA) were also conducted. RESULTS: After 1 year, the calculated incremental cost-effectiveness ratio (ICER) for group 1 versus group 2 was -$4,373 with group 1 (dHACA) being dominant over group 2 (SOC). PSA demonstrated that group 1 had 69.2% lower cost values with increased positive incremental effectiveness for 94.9% of values. A willingness to pay (WTP) curve showed that about 92% of interventions were cost effective for group 1 when $50,000 was paid. CONCLUSIONS: The results of this study demonstrated that dHACA added to SOC compared to SOC alone was extremely cost-effective in the defined trial population.

Assessment of Corneal Haze After PRK and the Effect of Sutureless Amniotic Membrane Graft by Corneal Densitometry.

PURPOSE: To assess whether densitometry analysis appropriately monitors the development of haze in myopic patients after photorefractive keratectomy (PRK) when compared to subjective slit-lamp haze grade examinations, and whether sutureless cryo-preserved amniotic membrane reduced postoperative haze development when compared to the standard bandage contact lens. METHODS: In this retrospective cohort at the Center for Refractive Surgery, Walter Reed National Military Medical Center, a secondary analysis of prospectively collected data was performed. In the prospective study, participants underwent PRK for myopia. Postoperatively, a standard bandage contact lens was applied to the dominant eye and a sutureless cryo-preserved amniotic membrane graft to the nondominant eye. Participants were evaluated at 1, 3, and 6 months postoperatively for haze formation and corneal densitometry using slit-lamp biomicroscopy and Scheimpflug imaging, respectively. RESULTS: Densitometry measurements at 6 months postoperatively were positively and significantly associated with the presence or absence of haze as assessed by slit-lamp examination in 39 patients (78 eyes; age range: 21 to 44 years). Eyes with increased densitometry measurements had 2.3 to 3.4 times the odds (P ⩽ .014) of having clinical haze on slit-lamp examination. Eyes with the amniotic membrane graft showed a positive correlation with increased corneal densitometry throughout most layers of the cornea. CONCLUSIONS: Densitometry analysis appears to be a useful tool to supplement slit-lamp examination in monitoring haze development after PRK. The amniotic membrane failed to show a reduction in corneal densitometry in myopic eyes after PRK. [J Refract Surg. 2020;36(5):293-299.].

Synthetic biodegradable alternatives to the use of the amniotic membrane for corneal regeneration: assessment of local and systemic toxicity in rabbits.

AIM: The aim of this study was to assess the local and systemic response to poly-lactic co-glycolic acid (PLGA) 50:50 membranes, developed as synthetic biodegradable alternatives to the use of human donor amniotic membrane in the treatment of limbal stem cell deficiency. METHODS: PLGA membranes of 2 cm diameter and 50 µm thickness were placed on one eye of rabbits and secured in place using fibrin glue and a bandage contact lens, suturing the eye close with a single stitch. Control animals were treated identically, with the absence of the membranes. Plain and microfabricated electrospun membranes (containing micropockets which roughly emulate the native limbal niche) were examined over 29 days. All animals were subjected to a detailed gross and histopathological observation as well as a detailed examination of the eye. RESULTS: Application of the membranes both with and without microfabricated pockets did not adversely affect animal welfare. There was complete degradation of the membranes by day 29. The membranes did not induce any significant local or systemic toxicity. Conjunctival congestion and corneal vascularisation were noted in a few control and PLGA-treated animals. Intraocular pressure was normal and the retinal status was unaltered. The ocular surface was clear and intact in all animals by the end of 29 days. CONCLUSION: Membranes of 50:50 PLGA can be safely applied to rabbit corneas without inducing any local or systemic toxicity and these break down completely within 29 days.

In vitro assessment of a novel, hypothermically stored amniotic membrane for use in a chronic wound environment.

Chronic wounds require extensive healing time and place patients at risk of infection and amputation. Recently, a fresh hypothermically stored amniotic membrane (HSAM) was developed and has subsequently shown promise in its ability to effectively heal chronic wounds. The purpose of this study is to investigate the mechanisms of action that contribute to wound-healing responses observed with HSAM. A proteomic analysis was conducted on HSAM, measuring 25 growth factors specific to wound healing within the grafts. The rate of release of these cytokines from HSAMs was also measured. To model the effect of these cytokines and their role in wound healing, proliferation and migration assays with human fibroblasts and keratinocytes were conducted, along with tube formation assays measuring angiogenesis using media conditioned from HSAM. Additionally, the cell-matrix interactions between fibroblasts and HSAM were investigated. Conditioned media from HSAM significantly increased both fibroblast and keratinocyte proliferation and migration and induced more robust tube formation in angiogenesis assays. Fibroblasts cultured on HSAMs were found to migrate into and deposit matrix molecules within the HSAM graft. These collective results suggest that HSAM positively affects various critical pathways in chronic wound healing, lending further support to promising qualitative results seen clinically and providing further validation for ongoing clinical trials.

Volumetric Assessment of Regenerative Efficacy of Demineralized Freeze-Dried Bone Allograft With or Without Amnion Membrane in Grade II Furcation Defects: A Cone Beam Computed Tomography Study.

Volumetric changes were evaluated to assess the regenerative efficacy of demineralized freeze-dried bone allograft (DFDBA) with and without amnion membrane (AM) in Grade II furcation defects both clinically and radiographically using cone beam computed tomography (CBCT). Sites were randomly assigned to Group I (DFDBA) and Group II (DFDBA + AM). Clinical parameters such as probing pocket depth, clinical attachment level, gingival recession, and horizontal probing depth were assessed at baseline, 3 months, and 6 months. Radiographic dimensions of the defect height, width, depth, and volume were assessed at baseline and 6 months postoperatively. DFDBA used with AM resulted in significant improvement in clinical and radiographic parameters when compared with DFDBA alone. The mean reductions in radiographic volume of the defect were 11.15 ± 6.39 mL for Group I and 17.02 ± 10.86 mL for Group II. Greater reduction in volume indicated a greater amount of healed regenerated tissue in Group II patients.

Pilot assessment of a human extracellular matrix-based vascular graft in a rabbit model.

BACKGROUND: Herein we describe a small-diameter vascular graft constructed from rolled human amniotic membrane (hAM), with in vitro evaluation and subsequent in vivo assessment of its mechanical and initial biologic viability in the early postimplantation period. This approach for graft construction allows customization of graft dimensions, with wide-ranging potential clinical applicability as a nonautologous, allogeneic, cell-free graft material. METHODS: Acellular hAMs were rolled into layered conduits (3.2-mm diameter) that were bound with fibrin and lyophilized. Constructs were seeded with human smooth muscle cells and cultured under controlled arterial hemodynamic conditions in vitro. Additionally, the acellular hAM conduits were surgically implanted as arterial interposition grafts into the carotid arteries of immunocompetent rabbits. RESULTS: On in vitro analysis, smooth muscle cells were shown to adhere to, proliferate within, and remodel the scaffold during a 4-week culture period. At the end of the culture period, there was histologic and biomechanical evidence of graft wall layer coalescence. In vivo analysis demonstrated graft patency after 4 weeks (n = 3), with no hyperacute rejection or thrombotic occlusion. Explants displayed histologic evidence of active cellular remodeling, with endogenous cell repopulation of the graft wall concurrent with degradation of initial graft material. Cells were shown to align circumferentially to resemble a vascular medial layer. CONCLUSIONS: The vascular grafts were shown to provide a supportive scaffold allowing cellular infiltration and remodeling by host cell populations in vivo. By use of this approach, "off-the-shelf" vascular grafts can be created with specified diameters and wall thicknesses to satisfy specific anatomic requirements in diverse populations of patients.

Treatment of chronic diabetic lower extremity ulcers with advanced therapies: a prospective, randomised, controlled, multi-centre comparative study examining clinical efficacy and cost.

Advanced therapies such as bioengineered skin substitutes (BSS) and dehydrated human amnion/chorion membrane (dHACM) have been shown to promote healing of chronic diabetic ulcers. An interim analysis of data from 60 patients enrolled in a prospective, randomised, controlled, parallel group, multi-centre clinical trial showed that dHACM (EpiFix, MiMedx Group Inc., Marietta, GA) is superior to standard wound care (SWC) and BSS (Apligraf, Organogenesis, Inc., Canton, MA) in achieving complete wound closure within 4-6 weeks. Rates and time to closure at a longer time interval and factors influencing outcomes remained unassessed; therefore, the study was continued in order to achieve at least 100 patients. With the larger cohort, we compare clinical outcomes at 12 weeks in 100 patients with chronic lower extremity diabetic ulcers treated with weekly applications of Apligraf (n = 33), EpiFix (n = 32) or SWC (n = 35) with collagen-alginate dressing as controls. A Cox regression was performed to analyse the time to heal within 12 weeks, adjusting for all significant covariates. A Kaplan-Meier analysis was conducted to compare time-to-heal within 12 weeks for the three treatment groups. Clinical characteristics were well matched across study groups. The proportion of wounds achieving complete closure within the 12-week study period were 73% (24/33), 97% (31/32), and 51% (18/35) for Apligraf, EpiFix and SWC, respectively (adjusted P = 0·00019). Subjects treated with EpiFix had a very significant higher probability of their wounds healing [hazard ratio (HR: 5·66; adjusted P: 1·3 x 10(-7) ] compared to SWC alone. No difference in probability of healing was observed for the Apligraf and SWC groups. Patients treated with Apligraf were less likely to heal than those treated with EpiFix [HR: 0·30; 95% confidence interval (CI): 0·17-0·54; unadjusted P: 5·8 x 10(-5) ]. Increased wound size and presence of hypertension were significant factors that influenced healing. Mean time-to-heal within 12 weeks was 47·9 days (95% CI: 38·2-57·7) with Apligraf, 23·6 days (95% CI: 17·0-30·2) with EpiFix group and 57·4 days (95%CI: 48·2-66·6) with the SWC alone group (adjusted P = 3·2 x 10(-7) ). Median number of grafts used per healed wound were six (range 1-13) and 2·5 (range 1-12) for the Apligraf and EpiFix groups, respectively. Median graft cost was $8918 (range $1,486-19,323) per healed wound for the Apligraf group and $1,517 (range $434-25,710) per healed wound in the EpiFix group (P < 0·0001). These results provide further evidence of the clinical and resource utilisation superiority of EpiFix compared to Apligraf for the treatment of lower extremity diabetic wounds.

Scanning electron microscopic assessment on surface morphology of preserved human amniotic membrane after gamma sterilisation.

Human amniotic membrane that has been processed and sterilised by gamma irradiation is widely used as a biological dressing in surgical applications. The morphological structure of human amniotic membrane was studied under scanning electron microscopy (SEM) to assess effects of gamma radiation on human amniotic membrane following different preservation methods. The amniotic membrane was preserved by either air drying or submerged in glycerol before gamma irradiated at 15, 25 and 35 kGy. Fresh human amniotic membrane, neither preserved nor irradiated was used as the control. The surface morphology of glycerol preserved amnion was found comparable to the fresh amniotic membrane. The cells of the glycerol preserved was beautifully arranged, homogonous in size and tended to round up. The cell structure in the air dried preserved amnion seemed to be flattened and dehydrated. The effects of dehydration on intercellular channels and the microvilli on the cell surface were clearly seen at higher magnifications (10,000×). SEM revealed that the changes of the cell morphology of the glycerol preserved amnion were visible at 35 kGy while the air dried already changed at 25 kGy. Glycerol preservation method is recommended for human amniotic membrane as the cell morphological structure is maintained and radiation doses lower than 25 kGy for sterilization did not affect the appearance of the preserved amnion.

[Heterogeneity of costs and performance for penetrating eye injuries and suturing amniotic membranes under DRG conditions : Analysis of case constellations of the G-DRG C01B of the Regensburg University eye clinic]. / Kosten- und Leistungsheterogenität bei penetrierenden Augenverletzungen und Amnionmembranaufnähungen unter DRG-Bedingungen : Analyse von Fallkonstellationen der G-DRG C01B der Universitätsaugenklinik Regensburg.

BACKGROUND: Patients with penetrating eye injuries are a very heterogeneous group both medically and economically. Since 2009, treatment involving sutures for open eye injuries and cases requiring amniotic membrane transplantation (AMT) were allocated to DRG C01B of the German diagnosis-related group system. However, given the significant clinical differences between these treatments, an inhomogeneity of costs to performance is postulated. This analysis describes case allocation problems within the G-DRG C01B category and presents solutions. METHODS: A retrospective analysis was conducted from the standardized G-DRG data of 277 patients with open eye injuries and AMT between 2007 and 2008, grouped under the 2008 G-DRG system version to the G-DRG C01Z category. This data was provided by the Department of Ophthalmology at the University Hospital Regensburg. Additionally case-based data of the following were supplemented: length of surgery, time of anesthesia and intensity of patient care. Fixed and variable costs were determined for surgery and other inpatient treatment. Finally, an analysis of the heterogeneity of costs within the G-DRG C01B of the G-DRG system 2009 was implemented. RESULTS: Inhomogeneity was evident within the G-DRG C01B of the G-DRG system 2009 for the two groups suture of open eye injuries and AMT concerning the parameters length of stay, proportion of high outliers and cost per case. Multiple surgeries during an inpatient stay lead to an extended length of stay and increasing costs, especially within the AMT group. Intensity of patient care and the consideration of patient comorbidity did not yield relevant differences. CONCLUSION: The quality of the G-DRG system is measured by its ability to obtain adequate funding for highly complex and heterogeneous cases. Specific modifications of the G-DRG structures could increase the appropriateness of case allocation for patients with open eye injuries within the G-DRG C01B of the German DRG system 2009. As a result of the present study, cases with amniotic membrane transplantation should not be allocated to the G-DRG C01B. A petition has been presented by the German Association of Ophthalmology (DOG) to the German DRG Institute to restructure the G-DRG C01B. Data-based analysis is an essential prerequisite for a constructive development of the G-DRG system and a necessary tool for the active participation of medical societies in this process.

[Biomechanic and biological activity assessment of concavity-convex amniotic membrane].

This paper conducted research on biomechanical characteristics and biological activity of concavity-convex amniotic membrane (CCAM) and discussed its superiority as ocular surface repair material. Folding and compression with vacuum of fresh amniotic membrane were used to prepare CCAM. After cutting the striga of CCAM, sixteen CCAM tissue section were chosen at random to test their tensile strength using electronic universal testing machine. The bilayer amniotic membrane (BAM), the double-deck amniotic membrane (DAM) and the monolayer amniotic membrane (MAM) were as controls. The test parameters included yield strength, tensile strength, elongation at break, elastic modulus and so on. The cytokines of fresh amniotic membrane (FAM), MAM and CCAM were analyzed by radioimmunoassay method. The CCAM was obviously thicker than MAM and DAM. After 15 min in PBS, the CCAM tissue can recover the normal shape. The tensile strength and the elongation at break of CCAM were higher than those of the MAM and the DAM (P < 0.05). The elastic modulus of the CCAM was smaller than that of the MAM and the DAM (P < 0.05). The content of 10 cytokines [epidermal growth factor (EGF), fibroblast growth factor (FGF), b-fibroblast growth factor b-FGF, hepatocyte growth factor (HGF), transforming growth factor-beta (TGF-beta), insulin-like growth factor (IGF), platelet-derived growth factor (PDGF), vascular endothelial growth factor (VEGF), nerve growth factor (NGF), brain-derived nellrotrophic factor (BDNF), ciliary neurotrophic factor (CNTF)] of CCAM decreased significantly compared with the FAM and increased significantly compared with MAM and DAM in 6 cytokines (EGF, FGF, HGF, TGF-betap, PDGF, NGF; P < 0.05). The CCAM composites is thinner and has higher cytokine content than MAM, and better biomechanical properties than the MAM and the DAM, showing the superiority as ocular surface repair material.

Cautery fixation for amniotic membrane transplant in pterygium surgery.

PURPOSE: To report a technique using cautery fixation of the amniotic membrane transplant in pterygium excision. METHODS: The amniotic membrane transplant is oversized 3-4 mm in both dimensions (1.5-2 mm on each side). The transplant is placed in position, and the excess is tucked subconjunctivally 270 degrees. Limbal fixation sutures using 9-0 Vicryl in a buried fashion are placed, and then, amniotic membrane transplant (AMT) overlying the cornea is excised. Cautery fixation of the AMT in a grid pattern using the eraser tip is performed. The cautery power is started low and titrated up until the appropriate reaction of the graft is noted upon application. Forceps are used for countertraction to prevent the eraser tip from lifting the AMT graft after fixating it to the underlying episclera. RESULTS: This technique was used on 17 consecutive patients with pterygia (12 primary and 5 recurrent). Average surgical time was 22.65 ± 2.57 minutes. No AMT malposition, dislocation, or loss and no granuloma formation were experienced. Although follow-up up to this point is short (average: 7.12 months, range: 2-18 months), no recurrences have occurred. CONCLUSIONS: This technique provides a quick, inexpensive, and effective method of AMT fixation for use in pterygium surgery.

Assessment of the use of cryopreserved x freeze-dried amniotic membrane (AM) for reconstruction of ocular surface in rabbit model.

PURPOSE: To determine the efficacy of freeze-dried amniotic membrane (AM) for reconstruction of the ocular surface in rabbit eyes. METHODS: The sterilized, freeze-dried amniotic membrane (lyophilized or FD-AM) is a preservative method that uses the drying by freezing process to maintain the AM well preserved for a long time even at room temperature. This paper is an experimental animal interventional study. One eye of each of 15 male New Zealand rabbits (1.5 - 3.0 kg) had the central cornea marked with a 6.0 mm trephine. The marked area was deepithelialized with a No.15 blade. The denuded corneal surface was covered as follows: Group 1: cryopreserved AM (n=6); Group 2: freeze-dried AM (n=6); and Group 3: not covered (control group, n=3). The AM in group 1 and 2 and the periphery of the denuded area in group 3 were secured with continuous 10-0 nylon sutures. The clinical evaluation was made by a blinded observer and graded on a four-point scale (1= minimal, 4= marked) for conjunctival and ciliary hyperemia, eyelid edema, corneal neovascularization, corneal opacity and reepithelialization on postoperative (PO) days 1, 7 and 30 . After PO day 30, the rabbits were euthanized and their corneas were sent for histopathological and ultrastructural analysis to evaluate tissue inflammation, reepithelialization, and basement membrane integrity. RESULTS: Two eyes in group 2 had a corneal infection and were excluded from the analysis. No statistically significant differences among the three groups were found (p>0.05) regarding the clinical evaluation on 1st, 7th and 30th PO days. On transmission electron microscopy, the basement membrane in lyophilized and control groups was more continuous and homogeneous than in the glycerol group. CONCLUSIONS: The freeze-drying method seems to be a good option to preserve human amniotic membrane to be used in ocular surface reconstruction. This preservative method reduces the preservation costs and may enhance the use of AM, facilitating its storage and transport.

Assessment of the use of cryopreserved x freeze-dried amniotic membrane (AM) for reconstruction of ocular surface in rabbit model / Avaliação do uso da membrana amniótica (MA) criopreservada x liofilizada na reconstrução da superfície ocular em coelhos

PURPOSE: To determine the efficacy of freeze-dried amniotic membrane (AM) for reconstruction of the ocular surface in rabbit eyes. METHODS: The sterilized, freeze-dried amniotic membrane (lyophilized or FD-AM) is a preservative method that uses the drying by freezing process to maintain the AM well preserved for a long time even at room temperature. This paper is an experimental animal interventional study. One eye of each of 15 male New Zealand rabbits (1.5 - 3.0 kg) had the central cornea marked with a 6.0 mm trephine. The marked area was deepithelialized with a No.15 blade. The denuded corneal surface was covered as follows: Group 1: cryopreserved AM (n=6); Group 2: freeze-dried AM (n=6); and Group 3: not covered (control group, n=3). The AM in group 1 and 2 and the periphery of the denuded area in group 3 were secured with continuous 10-0 nylon sutures. The clinical evaluation was made by a blinded observer and graded on a four-point scale (1= minimal, 4= marked) for conjunctival and ciliary hyperemia, eyelid edema, corneal neovascularization, corneal opacity and reepithelialization on postoperative (PO) days 1, 7 and 30 . After PO day 30, the rabbits were euthanized and their corneas were sent for histopathological and ultrastructural analysis to evaluate tissue inflammation, reepithelialization, and basement membrane integrity. RESULTS: Two eyes in group 2 had a corneal infection and were excluded from the analysis. No statistically significant differences among the three groups were found (p>0.05) regarding the clinical evaluation on 1st, 7th and 30th PO days. On transmission electron microscopy, the basement membrane in lyophilized and control groups was more continuous and homogeneous than in the glycerol group. CONCLUSIONS: The freeze-drying method seems to be a good option to preserve human amniotic membrane to be used in ocular surface reconstruction. This preservative method reduces the preservation costs and may enhance...

OBJETIVO: Avaliar a eficácia da liofilização da membrana amniótica (MA) para a reconstrução da superfície ocular em coelhos. MÉTODOS: A liofilização é processo de preservação que mantém a MA estável durante longo tempo mesmo em temperatura ambiente. A córnea de um olho de cada coelho macho da raça Nova Zelândia foi marcada e desepitelizada. Essa área desepitelizada foi coberta com: Grupo 1: MA criopreservada (n=6); Grupo 2: MA liofilizada (n=6) e Grupo 3: Não coberta (n=3). A MA nos grupos 1 e 2 e a periferia da córnea no grupo 3 foram suturadas com nylon 10-0. A avaliação clínica foi realizada por um observador cego em relação à hiperemia, neovascularização e edema de córnea e reepitelização nos dia 1, 7 e 30 pós-operatórios. Após o dia 30 os ratos foram eutanizados e suas córneas enviadas para análise histopatológica e ultra-estrutural. RESULTADOS: Dois olhos no grupo 2 foram excluídos da análise devido à infecção. Não foi encontrada diferença estatisticamente significante entre os grupos em relação à avaliação clínica. Na microscopia eletrônica de transmissão, a membrana basal nos grupos de MA liofilizada e controle foi mais contínua e homogênea em relação ao grupo da MA criopreservada. CONCLUSÕES: O processo de liofilização parece ser boa opção para a preservação da membrana amniótica humana para utilização na reconstrução da superfície ocular.