The inclusion criteria were mainly based on the preserved quality of the globes. One globe was used from each species and was dissected to examine the cornea and limbus.
The tissue was fixed in 10% neutral buffered formalin at room temperature (RT) overnight. The tissue was then placed in a tissue-embedding cassette and processed. Each processed ocular globe was then embedded in paraffin wax using a mold. A microtome (Leica RM2235; Leica, Germany) was used to make 4 µm sections that were mounted on slides (Surgipath X-tra Adhesive Precleaned Microslides; Leica Biosystems, USA). Twenty slides were made from each embedded block. All slides were placed in an incubator (Leec, UK) at 37°C overnight.
The tissue was fixed in 10% neutral buffered formalin at room temperature (RT) overnight. The tissue was then placed in a tissue-embedding cassette and processed. Each processed ocular globe was then embedded in paraffin wax using a mold. A microtome (Leica RM2235; Leica, Germany) was used to make 4 µm sections that were mounted on slides (Surgipath X-tra Adhesive Precleaned Microslides; Leica Biosystems, USA). Twenty slides were made from each embedded block. All slides were placed in an incubator (Leec, UK) at 37°C overnight.