Equine pericardium for tectonic globe repair

Management of scleral melt

Scleral melting, while rare, can lead to significant ocular morbidity. Several possible risk factors for scleral melt have been identified, such as infection, autoimmune disease, trauma, and post-surgical state, and these may act in combination with each other. Treatment should be tailored according to the etiology and severity of the scleral melt. Medical management may be indicated, especially in cases of autoimmune-related melt; however, surgical procedures are often necessary due to compromised ocular integrity and limited penetration of medications into the avascular sclera. An understanding of the surgical options available and their operative outcomes is particularly important when choosing the appropriate treatment protocol for each patient.

Structural and Biochemical Changes in Pericardium upon Genipin Cross-Linking Investigated Using Nondestructive and Label-Free Imaging Techniques

Tissue cross-linking represents an important and often used technique to enhance the mechanical properties of biomaterials. For the first time, we investigated biochemical and structural properties of genipin (GE) cross-linked equine pericardium (EP) using optical imaging techniques in tandem with quantitative atomic force microscopy (AFM). EP was cross-linked with GE at 37 °C, and its biochemical and biomechanical properties were observed at various time points up to 24 h. GE cross-linked EP was monitored by the normalized ratio between its second-harmonic generation (SHG) and two-photon autofluorescence emissions and remained unchanged for untreated EP; however, a decreasing ratio due to depleted SHG and elevated autofluorescence and a fluorescence band at 625 nm were found for GE cross-linked EP. The mean autofluorescence lifetime of GE cross-linked EP also decreased. The biochemical signature of GE cross-linker and shift in collagen bands were detected and quantified using shifted excitation Raman difference spectroscopy as an innovative approach for tackling artifacts with high fluorescence backgrounds. AFM images indicated a higher and increasing Young's modulus correlated with cross-linking, as well as collagen structural changes in GE cross-linked EP, qualitatively explaining the observed decrease in the second-harmonic signal. In conclusion, we obtained detailed information about the biochemical, structural, and biomechanical effects of GE cross-linked EP using a unique combination of optical and force microscopy techniques in a nondestructive and label-free manner.

Pericardium Patch Graft for Severe Corneal Wound Burn

Purpose:

To report a novel management technique using pericardial patch graft for severe corneal wound burn following phacoemulsification of dense cataract with shallow anterior chamber (AC) and overfilled AC with viscoelastic.

Methods:

Case report.

Results:

A 46-year-old patient with a shallow AC and dense cataract, who underwent phacoemulsification using “soft shell” technique had severe wound burn which was refractory to conventional management with corneal suturing and placing bandage contact lens. He underwent Tutoplast^® (Innovative Ophthalmic Products, Inc., Costa Mesa, CA, USA) pericardium patch graft, which fully resorbed and resolved the wound leak over 6 weeks, leaving a well-healed corneal wound.

Conclusion:

Pericardium patch graft is a safe and effective technique to manage extensive phaco wound burn which is refractory to conventional management options.

Treatment of Progressive Scleromalacia Perforans by Tectonic Enhancement With Lyophilized Equine Pericardium

PURPOSE

To describe the off-label use of lyophilized equine pericardium for tectonic enhancement of the sclera in a case of progressive scleromalacia perforans.

METHODS

An 82-year-old woman with a history of varicella zoster virus sclerokeratitis presented with a progressively expanding scleral thinning at the superonasal quadrant of the anterior sclera of her left eye. The eye was blind because of intractable glaucoma. To avoid perforation of the exposed choroid, a single layer of lyophilized equine pericardium was sutured over the scleral perforation. After performing a conjunctival peritomy in the involved superonasal area, the pericardium was trimmed, fixated on the anterior sclera with 4 Nylon 9 to 0 interrupted sutures, and tucked underneath the conjunctival pocket. The conjunctiva was adapted with 6 Vicryl 8 to 0 interrupted sutures.

RESULTS

The postoperative course was uneventful. At 12 months after surgery, slit-lamp biomicroscopy showed a stable subconjunctival sheet covering the staphyloma, whereas anterior segment optical coherence tomography demonstrated thickening of the ocular wall, suggesting successful integration of the pericardium.

CONCLUSIONS

Suturing of equine pericardium over a scleral defect was feasible allowing successful reinforcement of the staphyloma in a case of severe scleromalacia perforans.

Mammalian Pericardium-Based Bioprosthetic Materials in Xenotransplantation and Tissue Engineering

Bioprosthetic materials based on mammalian pericardium tissue are the gold standard in reconstructive surgery. Their application range covers repair of rectovaginal septum defects, abdominoplastics, urethroplasty, duraplastics, maxillofacial, ophthalmic, thoracic and cardiovascular reconstruction, etc. However, a number of factors contribute to the success of their integration into the host tissue including structural organization, mechanical strength, biocompatibility, immunogenicity, surface chemistry, and biodegradability. In order to improve the material's properties, various strategies are developed, such as decellularization, crosslinking, and detoxification. In this review, the existing issues and long-term achievements in the development of bioprosthetic materials based on the mammalian pericardium tissue, aimed at a wide-spectrum application in reconstructive surgery are analyzed. The basic technical approaches to preparation of biocompatible forms providing continuous functioning, optimization of biomechanical and functional properties, and clinical applicability are described.

Amniotic membrane, clinical applications and tissue engineering. Review of its ophthalmic use

The use of amniotic membrane in ophthalmology has been increasing in recent years due to its multiple biological and tectonic properties, improvement in the process of obtaining, ease of use, and advancement in tissue engineering. The amniotic membrane has become one of the main adjuvant treatments, in ophthalmic surgery as well as in other medical-surgical specialties. The development of tissue engineering has allowed it to be used, not only in its classic form, but also by the use of drops and other presentations. The different steps prior to its use (preparation and conservation), the different surgical techniques, and their main clinical applications are described throughout the article.