Cross-Sectional Imaging Analysis of Epiretinal Membrane Involvement in Unilateral Open-Angle Glaucoma Severity.

Purpose: To determine the relevance of epiretinal membranes (ERMs) in primary open-angle glaucoma (POAG) and potential risk for glaucoma severity. Methods: Sixty eyes of 30 patients with POAG who had a unilateral ERM were analyzed; 60 nonglaucomatous eyes of 30 patients with a unilateral ERM also were recruited in this institutional cross-sectional study. Patients underwent swept-source (SS) optical coherence tomography (OCT) imaging and visual field testing. Intraindividual differences in the SS-OCT retinal nerve fiber layer (RNFL) disc cupping area measurements and visual field outcomes were analyzed in the two groups. Results: In patients with POAG, the mean circumpapillary RNFL thickness in the eyes with an ERM was 75.6 ± 16.5 µm superiorly and 71.8 ± 26.0 inferiorly compared with the fellow eyes without an ERM (87.2 ± 23.6 µm, P = 0.0061 and 81.3 ± 27.7 µm, P = 0.034, respectively). The areas of disc cupping and cup-to-disc ratio seen on OCT horizontal and vertical B-scans were larger in eyes with an ERM than in the fellow eyes without ERM (P = 0.0004 and P = 0.0011, respectively). The average mean deviations were -11.6 ± 7.5 dB in the ERM group and -8.19 ± 6.4 dB in the group with no ERM (P = 0.029). Eyes with an ERM received more antiglaucoma eye drops (P = 0.018). Those differences were not seen between eyes with an ERM or fellow eyes in patients without glaucoma. Conclusions: The presence of an ERM can be a potential risk factor for unilateral severity in eyes with POAG.

Surgical feasibility and biocompatibility of wide-field dual-array suprachoroidal-transretinal stimulation prosthesis in middle-sized animals.

PURPOSE: To investigate the safety and efficacy of a newly-developed wide-field dual-array suprachoroidal-transretinal stimulation (STS) prosthesis in middle-sized animals. METHODS: The prosthesis consisted of two arrays with 50 to 74 electrodes. To test the feasibility of implanting the prosthesis and its efficacy, the prosthesis was implanted for 14 days into two rabbits. Optical coherence tomography (OCT) and ophthalmoscopy were performed 7 and 14 days after the implantation. Then the rabbits were euthanized, eyes were enucleated, and the posterior segment of the eye was examined histologically. In a second experiment, the arrays were implanted into two cats, and their ability to elicit neural responses was determined by electrically evoked potentials (EEPs) at the chiasm and by optical imaging of the retina. RESULTS: All arrays were successfully implanted, and no major complications occurred during the surgery or during the 2-week postoperative period. Neither OCT nor ophthalmoscopy showed any major complications or instability of the arrays. Histological evaluations showed only mild cellular infiltration and overall good retinal preservation. Stimulation of the retina by the arrays evoked EEPs recorded from the chiasm. Retinal imaging showed that the electrical pulses from the arrays altered the retinal images indicating an activation of retinal neurons. The thresholds were as low as 100 µA for a chiasm response and 300 µA for the retinal imaging. CONCLUSION: Implantation of a newly-developed dual-array STS prosthesis for 2 weeks in rabbits was feasible surgically, and safe. The results of retinal imaging showed that the dual-array system was able to activate retinal neurons. We conclude that the dual-array design can be implanted without complication and is able to activate retinal neurons and optic nerve axons.

Effect of pre-treatment with St John's Wort on nephrotoxicity of cisplatin in rats.

An herbal health care supplement, St John's Wort (SJW, Hypericum perforatum) has become widely used in the treatment of depression, and is known to interact with therapeutic drugs. Here we report a preventive effect of SJW on cisplatin nephrotoxicity in rats. Rats were given SJW (400 mg/kg/day, p.o.) for 10 consecutive days, and were injected with cisplatin (5 mg/kg, i.v.) on the day after the final SJW treatment. Cisplatin treatment increased the serum creatinine level, which is an index of nephrotoxicity, to 1.51+/-0.22 mg/dl (mean+/-SE) from 0.28+/-0.05 mg/dl (control) on day 5 after the cisplatin injection. This increase fell significantly to 0.86+/-0.13 mg/dl by pre-treatment with SJW. Cisplatin-induced histological abnormality of the kidney was blocked by pre-treatment with SJW. When SJW was administered for 10 days, the amounts of renal metallothionein (MT) and hepatic multidrug resistance protein 2 (Mrp2) were increased to 164.8+/-13.0% and 220.8+/-39.3% (mean+/-SE) of controls, respectively. GSH levels in the kidney and liver were not changed. Total and free cisplatin concentration in serum was not influenced by SJW treatment. In conclusion, the results suggest that pre-treatment with SJW may diminish cisplatin nephrotoxicity.