2020–2021 BCSC Basic and Clinical Science Course™
4 Ophthalmic Pathology and Intraocular Tumors
Part I: Ophthalmic Pathology
Chapter 2: Specimen Handling
Processing and Staining
Tissue Processing
Tissue processing involves dehydration of the specimen to allow infiltration of the tissue with paraffin. The tissue is then embedded in a paraffin block, which mechanically stabilizes the tissue, enabling it to be cut into very thin sections.
The organic solvents used in tissue processing—for example, ethanol and xylene—dissolve lipids and may dissolve some synthetic materials. Routine processing usually dissolves intraocular lenses made of acrylic or silicone but does not dissolve sutures made of silk, nylon, or other synthetic materials.
The processing of a routine specimen usually takes a day. Techniques for the rapid processing of special surgical pathology material are generally reserved for small biopsy specimens that require urgent handling. Rapid processing usually results in inferior tissue preparations and therefore should not be requested routinely. Surgeons should communicate directly with their pathologists about the availability and shortcomings of these techniques.
Excerpted from BCSC 2020-2021 series: Section 4 - Ophthalmic Pathology and Intraocular Tumors. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.