[Glaucoma today: detection and therapeutic progress]

Study of minimally invasive radiofrequency ablation of the ciliary body for the treatment of glaucoma in rabbits

The aim of the present study was to explore the safety and effectiveness of radiofrequency ablation (RFA) of the ciliary body for the treatment of glaucoma. A glaucoma model was established in New Zealand white rabbits, which were then treated with RFA of the ciliary body, utilizing an XL-1-type RF meter developed by the Chinese PLA General Hospital. After treatment, general ocular investigation, including ocular pressure was carried out, the anterior chamber was imaged via ultrasound biomicroscopy, and the pathological changes were observed via hematoxylin and eosin (H&E) staining. It was determined that the glaucoma model was successfully established in the New Zealand white rabbit by inducing high intraocular pressure (IOP). After RFA treatment, ablation spots were observed but no clear anterior chamber reaction was found. The ablation group showed a steady and continuous decrease of IOP, which was significantly lower than the model group at days 3 and 7 (P<0.05). A sclera pathway was observed in the ablation site 1-day post-treatment, which had mostly recovered by day 7. H&E staining demonstrated shedding of the ciliary epithelium, and an unclear boundary between muscle layer and blood vessel at day 1. This had fully recovered by day 14, with clear ciliary layers and well-arranged muscle structures observed. The present study suggested that treatment with RFA could decrease IOP without substantial side effects in the glaucoma model in the rabbit. Therefore, it could be used as a strategy to control IOP and as a treatment for glaucoma in the clinic.

Heat shock protein 72 confers protection in retinal ganglion cells and lateral geniculate nucleus neurons via blockade of the SAPK/JNK pathway in a chronic ocular-hypertensive rat model

Optic nerve transection increased the expression of heat shock protein 72 (HSP72) in the lateral geniculate body, indicating that this protein is involved in the prevention of neuronal injury. Zinc sulfate and quercetin induced and inhibited the expression of HSP72, respectively. Intraperitoneal injections of zinc sulfate, SP600125 (c-Jun N-terminal kinase inhibitor), or quercetin were performed on retinal ganglion cells in a Wistar rat model of chronic ocular hypertension. Our results showed that compared with the control group, the expression of HSP72 in retinal ganglion cells and the lateral geniculate body was increased after the injection of zinc sulfate, but was decreased after the injection of quercetin. The expression of phosphorylated c-Jun N-terminal kinases and phosphorylated c-Jun were visible 3 days after injection in the control group, and reached a peak at 7 days. Zinc sulfate and SP600125 significantly decreased the expression of p-c-Jun, whereas quercetin significantly enhanced the expression of this protein. These results suggest that HSP72 protects retinal ganglion cells and lateral geniculate body in a rat model of chronic ocular hypertension from injury by blocking the activation of the stress-activated kinase/c-Jun N-terminal kinase apoptotic pathway.