Assessing the brain through the eye: New ways to explore hepatic encephalopathy

Area of Science:

• Neuroscience
• Gastroenterology
• Ophthalmology

Background:

• Minimal hepatic encephalopathy (mHE) significantly impacts daily life and mortality.
• Early diagnosis and treatment of mHE impairments remain challenging.
• Portal hypertension is a key factor driving the inflammatory processes in mHE.

Purpose of the Study:

• To describe an indirect diagnostic method for early-stage mHE.
• To investigate conjunctival vascularization and mast cell hyperplasia as indicators of portal hypertension.
• To correlate ocular histological changes in mHE with behavioral task deficits.

Main Methods:

• An animal model of mHE was created using triple portal vein ligation in rats.
• Rats were trained on stimulus-response and spatial working memory tasks.
• Ocular vascularization, mast cell expression, and astrocyte density (GFAP-IR) were analyzed.

Main Results:

• Rats with portal hypertension (HT group) exhibited deficits in stimulus-response task acquisition.
• The HT group showed decreased GFAP-IR density but increased mast cells and vascularization.
• No significant differences were observed in spatial working memory tasks between groups.

Conclusions:

• Ocular changes, including vascularization and mast cell hyperplasia, are associated with portal hypertension in an mHE model.
• These findings suggest the eye may serve as a potential diagnostic tool for mHE.
• Further research is needed to validate the eye as a diagnostic biomarker for mHE.