This chapter covers the methods that pathology laboratories use to process tissue specimens with the final product being glass slides. These specimens include globes and ocular adnexal biopsy tissues, as well as specimens requiring evaluation of surgical margins. The main steps for processing of specimens are
communication with the pathologist regarding specimen orientation (as indicated)
fixation to preserve the tissue
gross dissection to prepare the specimen for histologic sectioning
tissue processing, typically into paraffin
slide preparation and tissue staining
The most common method used to make the tissue firm enough to be cut into thin sections is embedding in paraffin and cutting sections (permanent sections), which is discussed in this chapter. Another method used, typically for evaluation of surgical margins of resection, is frozen section, which is discussed in Chapter 3. Permanent sections are always preferred in ophthalmic pathology because this technique allows better preservation of morphological features than do frozen sections, which are prone to artifact.
Discussion between the ophthalmologist and the pathologist prior to the biopsy or surgery is important, as it enables them to determine the best way to collect a specimen and submit it to the laboratory. The following section discusses this topic.
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.