There are three types of corneal dystrophies: anterior, posterior and stromal. Lattice corneal dystrophies (LCD) are a part of stromal dystrophies and characterized by an accumulation of amyloid deposition with in the stroma. LCD is diognosed with biomicroscopic examination and the diognosis confirmed by histological examination after keratoplasty. Genetic analysis may be required for specific cases.
In our study, the corneal buttons of four patients, three of them belonging to the same family, who applied to the Ophthalmology Clinic of Cerrahpasa Medical Faculty with lattice corneal dystrophy, histologically examined with light and electron microscopies.
For light microscopic examination, a portion of corneal buttons were embedded into the parafine blocks after fixation and dehidration steps. Parafine blocks were cut as 5 µ sections and stained with hematoxylen & eosin and periodic acid & Schiff (PAS). For electron microscopic examination, the other pieces of corneal buttons were fixed glutaraldehyde and osmium tetroxide (OsO4). After the dehidration, corneal buttons embedded into araldite and the blocks were sectioned 500-700Å. The sections taken on copper grids were analyzed and photographed.
In the light microscopic examination of hematoxylin & eosin stained corneal buttons; the local deposits seen in a circular arrangment, was observed and it was suggested that these were amyloid deposits. In only one of the four patients’ corneal buttons, these deposits were seen in the stroma, but in the other three patients’, belonging to the same family, deposits increased epithelial level and led to significant damage to the epithelium. When the samples were stained with periodic acid- Schiff reagent, positive reaction was observed in these deposits. Electron microscopic examination revealed that typical amyloid fibrils also occurred in deposits.
Despite local areas were damaged due to these amyloid deposits, no inflammation was observed.
As in other corneal dystrophies, a systematic approach and histopathological evaluation, including special staining and ultrastructural studies, are critical to a correct diagnosis, also in LCD. Therefore, it is important to make a histopathologic examination for all grafts clinically diagnosed or undiagnosed.
To cite this abstract:Ismail SECKIN, Mustafa Erdogan CICIK, Osman Sevki ARSLAN, Basak ISILDAR, Cezmi DOĞAN, Ozan BURGAZDERE, Samira HAGVERDİYEVA; Light and electron microscopic evaluation of lattice corneal dystrophy (LCD). The 16th European Microscopy Congress, Lyon, France. https://emc-proceedings.com/abstract/light-and-electron-microscopic-evaluation-of-lattice-corneal-dystrophy-lcd/. Accessed: October 29, 2020
EMC Abstracts - https://emc-proceedings.com/abstract/light-and-electron-microscopic-evaluation-of-lattice-corneal-dystrophy-lcd/