Histological investigation of the eye tissue using different fixatives and different tissue preparation methods

Objective: Fixation is the basic step in the investigation of the tissues by light microscopy and affects the following steps. There are different fixation methods and different fixatives are used for this purpose. In this study, it was planned to examine which fixative gives the best result in the examination of the eye tissue. In terms of preserving tissue integrity, the study aimed to examine the effects of six different tissue preparation methods on eye structure. Methods: Six different tissue processings methods, different dehydrating agent (alcohol and acetone) and different fixatives (10% formaline, Bouin and 4% paraformaldehyde) were applied to 24 eye tissues taken from 12 female Wistar Albino rats. Sections taken from the obtained blocks were stained with hematoxylin and eosin dye and evaluated histomorphologically under the light microscope. The suitability of the different fixatives and dehydration agents applied to eye tissues and the differences that occur in the tissues are indicated. Results: The histological structure of rat eye samples was investigated in terms of the cornea, sclera, choroid, retina, iris and ciliary body. There was not any important difference among the groups. Accordingly, it was observed that all evaluated parameters generally gave similar results in terms of morphology when tissue integrity and all structures were considered in group I, group II, group III, group IV, group V, and goup VI. However, when the integrity of the eye tissues was evaluated, it was observed that the integrity of the histological layers in the eyeball was best preserved in the group IV Bouin fixative and acetone group. When the layers were examined individually between the groups, it was determined that the cornea, sclera, choroid and retina structures did not differ significantly. Conclusion: For optimal histomorphological examinations, the tissue preparation process is important to follow. The more successful this process is, the better the level of detail in the microscope will be and it will provide a suitable basis for basic histomorphological examinations. According to the findings of our study, we can recommend using Bouin as a fixative and acetone as a dehydrating agent in the eye tissue preparation process. Further studies are needed to generalize and improve the results of this study.