Search

Biomedical engineering online 20(1), 102 (2021). doi:10.1186/s12938-021-00938-9, Published by BioMed Central, London

Canaloplasty is a well-established non-penetrating glaucoma surgery. Unsuccessful outcomes can be enhanced by micro-invasive 360° suture trabeculotomy (360°trabeculotomy), analyzed in this study.This retrospective study included twenty eyes of 19 patients, mean age 59.7±17.2 years, with primary open-angle glaucoma (POWG n = 14), pseudoexfoliation glaucoma (PEX n = 3), juvenile glaucoma (n = 2) and aphakic glaucoma (n = 1), who underwent micro-invasive 360° trabeculotomy after unsuccessful (intraocular pressure (IOP)21 mmHg under maximum glaucoma eye drop therapy (Meds)) canaloplasty. IOPs, Meds, complications and failure rates (IOP21 mmHg at two consecutive follow-ups) were evaluated. Complete success (no Meds) and qualified success (with Meds) rates for IOP levels ≤21 mmHg and ≤ 18 mmHg at the last follow-up were evaluated.IOPs and Meds were significantly reduced from before to 1 week (10.3±3.1 days) after 360° trabeculotomy (IOP, 28.3±6.0 mmHg to 15.8±4.5 mmHg; p0.001; Meds, 3.1 ± 1.2 to 1.0 ± 1.2; p0.001). IOPs (p = 0.37) and Meds (p = 0.33) did not decrease further from 1 week until the last follow-up (18.3 ± 8.2 months (IOP, 14.4±3.8 mmHg; Meds, 1.5±1.3)). Complete and qualified success was 25% (5/20) and 70% (14/20) for IOP ≤21 mmHg, as well as 25% (5/20) and 60% (12/20) for IOP ≤18 mmHg. Four eyes had postoperative hyphema, which resolved after a mean period of 4.0 ± 2.2 days. Five failures occurred after a mean of 40.6 ± 51.9 days after 360° trabeculotomy. All failures underwent trabeculectomy. Eyes that needed early (≤3 months post canaloplasty) 360° trabeculotomy showed higher IOPs before (p0.001) and lower (p = 0.03) IOPs 2 months post 360° trabeculotomy than eyes with late (3 months) 360° trabeculotomy surgery.360° trabeculotomy is a safe, micro-invasive, simple and successful method to enhance failed canaloplasty.

Graefe's archive for clinical and experimental ophthalmology 259(9), 2731-2741 (2021). doi:10.1007/s00417-021-05203-2, Published by Springer, Berlin ; Heidelberg

Journal of neural engineering 16(6), 066031 (2019). doi:10.1088/1741-2552/ab4113, Published by Institute of Physics Publishing, Bristol

BACKGROUND AND OBJECTIVE: To investigate the relationship between spatial contrast sensitivity (CS) and parafoveal cone density (PCD). PATIENTS AND METHODS: Fifteen healthy individuals (mean age: 26.1 years ± 4.5 years) and nine patients with hereditary retinal degeneration (mean age: 31.6 years ± 13.4 years) without media opacities were studied. The CS was measured by CSV-1000 (VectorVision, Greenville, OH). The cone mosaic was photographed with an adaptive optics scanning laser ophthalmoscope (AOSLO) with a 1° × 1° field of view centered on the fovea. The PCD was calculated in an annular area with radii of 0.38° and 0.43°. The CS was converted to the logarithm (logCS), and the area under the logCS function (AULCSF) was determined. RESULTS: The AULCSF was significantly and positively correlated with the PCD in the control (R 2 = 0.522; P = .003) and retinal degeneration (R 2 = 0.514; P = .03) groups. CONCLUSION: PCD can predict the spatial contrast sensitivity in normal subjects or patients with retinal degeneration without media opacities. [ Ophthalmic Surg Lasers Imaging Retina . 2017;48:106–113.]

To determine the relationship between re-reading the same line and saccadic disconjugacy in patients with convergence insufficiency-type intermittent exotropia [CI-type X(T)]. Eight patients with CI-type X(T) and ten healthy orthophoric individuals were studied. Video-oculography was used to assess the eye movements during the reading of a Japanese novel displayed on a 23-in. liquid crystal monitor placed 60 cm from the eyes. The sentences were displayed horizontally and read from left to right. The number of unintentional re-readings of the same line was counted, and the disconjugacy at the median of the saccade between the end of a line and the next line was determined. The number of re-readings of the same line in patients with CI-type X(T) was 4.9 ± 2.3 times which was significantly higher than that in the controls at 0.2 ± 0.4 times (P

To investigate the safety and efficacy of a newly-developed wide-field dual-array suprachoroidal–transretinal stimulation (STS) prosthesis in middle-sized animals. 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. 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. 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.