[Elevated Intraocular Pressure Induces Cellular Responses in the Retinal Capillaries]

Area of Science:

• Ophthalmology
• Cell Biology
• Vascular Biology

Background:

• Peripapillary bleedings are key indicators in early glaucoma diagnosis, suggesting capillary damage.
• Intraocular pressure (IOP) elevation and associated perfusion imbalances are critical factors in glaucoma.
• Optic nerve head biomechanics and astrocyte responses may also contribute to glaucoma pathogenesis.

Purpose of the Study:

• To investigate cellular and molecular mechanisms underlying capillary changes induced by elevated IOP.
• To develop in vivo and ex vivo models for high-resolution examination of IOP effects on capillaries.

Main Methods:

• Created an in vivo rat model with cauterized veins to elevate IOP and induce outflow resistance.
• Analyzed rat retinas for cellular and molecular changes post-IOP elevation.
• Cultivated brain microvascular endothelial cells (BMECs) and retinal microvascular endothelial cells (RMECs) in vitro under elevated IOP.

Main Results:

• In vivo studies revealed abnormal beta-III-tubulin expression in retinal capillary endothelial cells and pericytes.
• In vitro cultivation of BMECs and RMECs under elevated IOP confirmed the in vivo findings.
• Abnormal protein expression in capillaries represents an early cellular response to IOP elevation.

Conclusions:

• Elevated IOP triggers an unexpected capillary response, characterized by abnormal protein expression.
• This cellular response may serve as an early indicator of glaucoma-induced opticopathy.
• Findings may explain clinical signs like peripapillary bleedings and microinfarctions in glaucoma.