Photographic-Based Optical Evaluation of Tissues and Biomaterials Used for Corneal Surface Repair: A New Easy-Applied Method

Abstract

PurposeTissues and biomaterials used for corneal surface repair require fulfilling specific optical standards prior to implantation in the patient. However, there is not a feasible evaluation method to be applied in clinical or Good Manufacturing Practice settings. In this study, we describe and assess an innovative easy-applied photographic-based method (PBM) for measuring functional optical blurring and transparency in corneal surface grafts.MethodsPlastic compressed collagen scaffolds (PCCS) and multilayered amniotic membranes (AM) samples were optically and histologically evaluated. Transparency and image blurring measures were obtained by PBM, analyzing photographic images of a standardized band pattern taken through the samples. These measures were compared and correlated to those obtained applying the Inverse Adding-Doubling (IAD) technique, which is the gold standard method.ResultsAll the samples used for optical evaluation by PBM or IAD were histological suitable. PCCS samples presented transmittance values higher than 60%, values that increased with increasing wavelength as determined by IAD. The PBM indicated that PCCS had a transparency ratio (TR) value of 80.3±2.8%, with a blurring index (BI) of 50.6±4.2%. TR and BI obtained from the PBM showed a high correlation (ρ>|0.6|) with the diffuse transmittance and the diffuse reflectance, both determined using the IAD (p<0.005). The AM optical properties showed that there was a largely linear relationship between the blurring and the number of amnion layers, with more layers producing greater blurring.ConclusionsThis innovative proposed method represents an easy-applied technique for evaluating transparency and blurriness of tissues and biomaterials used for corneal surface repair.

Electrospun polycaprolactone (PCL)-amnion nanofibrous membrane prevents adhesions and promotes nerve repair in a rat model of sciatic nerve compression

“…Amniotic membrane has been widely used in the treatment of abdominal and pelvic adhesions, ophthalmic surgery, and chronic skin ulcers, due to their low immunogenicity [ 17 , 18 ]. The amnion has no membranous structure of blood vessels, lymph, or nerves [ 19 ], and the amniotic epithelial cells can secrete glial cell-derived neurotrophic factor, epidermal growth factor, and transforming growth factor [ 20 ].…”

Experimental study of tendon sheath repair via decellularized amnion to prevent tendon adhesion

“…The main components of this membrane include a variety of collagen, glycoprotein, and proteoglycan with good histocompatibility, low antigenicity, and strong permeability and can be completely degraded in vivo. Acellular amniotic membrane has been applied in the treatment of ocular surface disease, diabetic foot, periosteal perforation, urethral tissue defect, and other skin or mucosal injuries, which has achieved satisfactory results[ 21 , 22 ].…”