Seda ŞİMŞEK, Hasan KARA, Bilgehan MUTLU, Serhat EKER, Ayşegül BAYIR
Retina-Vitreus - 2026;35(3):265-276
Purpose: The aim of this study was to examine retinal alterations of glial fibrillary acidic protein (GFAP), SRY-box transcription factor 2 (SOX2), and thymus cell antigen 1 (THY1) in experimentally designed animal TBI models with different severity. Materials and Methods: New Zealand rabbits were randomly distributed into four groups: control group (n = 6), mild head trauma group (n = 7), moderate head trauma group (n = 7) and severe head trauma group (n = 7). Marmarou's modified impact acceleration model was used to induce TBI. We examined retinal sections using immunofluorescence labeling for GFAP, SOX2 and THY1. Results: Twenty-seven rabbits (weighing 2500-3500 g at age 1-2 years) were included in the study. GFAP levels were increased in all TBI models (mild, moderate, and severe) than in the control group (p<0.001). GFAP level was found to be significantly higher in the severe TBI group than in the mild and moderate groups. The difference in THY1 levels was statistically significant among groups (p<.001). It was found that as the severity of trauma increased, THY1 levels decreased significantly between the groups. SOX2 levels were observed higher in the moderate and severe TBI groups than in the control and mild TBI groups (p<0.001). No significant difference was found in SOX2 levels between the control and the mild TBI groups (p>0.05). Conclusion: This experimental study revealed that changes in neural biomarkers differed significantly between mild, moderate, and severe TBI groups. As trauma severity intensified, THY1 expression decreased while GFAP and SOX2 expression increased.
