Abstract
Purpose: :
To compare the effects of Davidson’s fixative solution in preserving the structure of eye tissues with those of 10% buffered formalin.
Methods: :
Sixteen normal rabbit eyes were used in the study. After enucleation the eyes were divided into three groups of similar proportion: A) Intact eyeballs immersed in Davidson’s solution; B) Intact eyeballs immersed in 10% buffered formalin; and C) Eyeballs immersed in 10% buffered formalin after removal of the cornea. Eyes in group A were left in Davidson’s solution for 16 to 24 hours then dehydrated in a series of graded alcohol solutions over 24 to 48 hours before gross dissection. Eyes in groups B and C were left in formalin until gross dissection. All the eyes were evaluated for any change such as retinal fold or damage. The eyes were embedded in paraffin for further processing and stained with hematoxylin and eosin for light microscopy.
Results: :
On gross dissection, the Davidson’s fixed eyes were easier to cut because they had a more robust structure compared to the formalin fixed eyes. In the Davidson’s fixed eyes there was no retinal detachment at the edge of the cuts, whereas in the formalin fixed eyes retinal detachment was noted at the edge of the cuts in 3 of 5 eyes in group B and in all eyes in group C. On light microscopy, the retinal structure was well preserved in group A. In contrast, groups B and C showed pronounced folding and separation of the neurosensory retina from retinal pigment epithelium. In addition, retinal tear and separation of nuclear layers of the retina was observed in some eyes.
Conclusions: :
In comparison to formalin, Davidson’s fixative solution provided excellent preservation of the retinal tissue. In addition, there was significant artifactual retinal detachment and retinal folding in the formalin fixed rabbit eyes. Removal of the cornea in formalin fixated eyes appeared to increase the rate of artifactual retinal detachment.
Keywords: retina • microscopy: fixation processing • retinal adhesion