Comparative analysis of optical properties in amniotic membrane products

Area of Science:

• Ophthalmology
• Biomaterials Science
• Medical Imaging

Background:

• Amniotic membranes (AMs) are used in treating various ocular surface diseases.
• Assessing the optical properties of AMs is crucial for understanding their impact on patient vision.
• Current methods for evaluating AM optical quality can be complex or costly.

Purpose of the Study:

• To compare the optical properties of different amniotic membrane (AM) products.
• To introduce and validate a modified photographic-based method for quantifying AM optical characteristics.
• To correlate optical measures with physical properties like thickness.

Main Methods:

• A photographic technique was employed to analyze standardized band patterns viewed through various AMs (Prokera® Plus, Prokera® Slim, Amniograft®, Ambio2®, Ambio5®) and a Collagen Shield.
• Blur Index (BI) was calculated based on the standard deviation of gray values, indicating image blurring.
• Transparency Ratio (TR) was determined by comparing the mean peak gray values of white bars, signifying brightness.

Main Results:

• Blur Indices (BIs) varied significantly across samples, from 0.97% (Ambio2®) to 22.58% (Ambio5®).
• Transparency Ratios (TRs) ranged from 0.906 to 1.018, with higher values indicating greater brightness.
• A strong inverse correlation was observed between BI and TR (r = -0.954), and thicker AMs generally exhibited higher BIs.

Conclusions:

• Optical transparency (TR) is inversely related to image blurring (BI) in amniotic membranes.
• Thicker AMs tend to have higher blur indices, potentially affecting visual acuity.
• The described photographic method provides a rapid, cost-effective means to evaluate AM optical quality and inform clinical application.