Abstract
Purpose :
Hexagonal-shaped corneal endothelial cells (CECs) are essential in maintaining corneal transparency for clear vision. In glaucoma patients, abnormal CEC function caused by high intraocular pressure (IOP) can contribute to vision loss. We developed a multi-scale imaging workflow to determine whether we could identify morphological and structural variations at at the nanoscopic level using a mouse model of high IOP induced by anterior chamber cannulation
Methods :
We cannulated the left eyes of wild-type (WT) mice using anterior chamber puncture, and controlled the IOP to be 40 mmHg by adjusting the height of the syringe; right eyes served as controls. We first used a custom visible-light optical coherence tomography (vis-OCT) to monitor the overall corneal damage in real-time. After one hour of hypertension treatment, we sacrificed the mice, isolated their corneas, and processed one half for single-molecule localization microscopy (SMLM) and the other half for scanning electron microscopy (SEM)
Results :
The vis-OCT images of control corneas showed a typical normal stroma (Fig. 1A). Increased corneal thickness was observed (Fig. 1B) with typical edematous appearance after maintaining 40 mmHg IOP for one hour. SMLM images showed the typical hexagonal structures of CECs in controls (Fig. 1C). However, after hypertension treatment, the intercellular tight junction structures labeled by ZO-1 became distorted dramatically, showing variations including extended filaments (Fig. 1E) or discontinuous and thinner junctional structures (Fig. 1D) between CECs. Using SEM, we identified similar hexagonal structures of CECs as showed in SMLM (Fig. 1F). Meanwhile, we observed the junctional structural variations on the surface level of CECs in hypertensive corneas, validating SMLM imaging results (Fig. 1G)
Conclusions :
We imaged corneal flat-mounts to reveal nanoscopic variations in CECs in hypertension mouse models using vis-OCT, SMLM, and SEM. Such disruptions of the intercellular junctional structure of CECs in corneas may contribute to the loss of transparency and vision damage in glaucoma patients with high IOP
This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.