So Hyun Bae

A Miniaturized, Eye-Conformable, and Long-Term Reliable Retinal Prosthesis Using Monolithic Fabrication of Liquid Crystal Polymer (LCP)

A novel retinal prosthetic device was developed using biocompatible liquid crystal polymer (LCP) to address the problems associated with conventional metal- and polymer-based devices: the hermetic metal package is bulky, heavy, and labor-intensive, whereas a thin, flexible, and MEMS-compatible polymer-based system is not durable enough for chronic implantation. Exploiting the advantageous properties of LCP such as a low moisture absorption rate, thermobonding, and thermoforming, we fabricate a small, light-weight, long-term reliable retinal prosthesis that can be conformally attached on the eye-surface. A LCP fabrication process using monolithic integration and conformal deformation was established enabling miniaturization and a batch manufacturing process as well as eliminating the need for feed-through technology. The functionality of the fabricated device was tested through wireless operation in saline solution. Its efficacy and implantation stability were verified through in vivo animal tests by measuring the cortical potential and monitoring implanted dummy devices for more than a year, respectively.

Neurosyphilis initially presenting as hemorrhagic exudative optic neuropathy in an immunocompetent patient.

We describe an unusual case of hemorrhagic exudative optic neuropathy as an initial presentation of neurosyphilis in an immunocompetent patient. The clinicians have to be alert to consider a diagnosis of syphilitic optic neuropathy in cases with hemorrhagic exudative optic neuropathy.

Klebsiella Endophthalmitis as Retinal Vasculitis with Prostatic Abscess.

PurposeTo describe an unusual case of endogenous Klebsiella endophthalmitis associated with prostatic abscess in an immunocompetent patient. Case ReportA 59-year-old previously healthy man presented with rapidly progressive retinal vasculitis in the left eye. He received an empirical antibiotic and antiviral agent intravenously followed by oral prednisolone until the etiology was identified; however, intraocular inflammation in the left eye continued to worsen, followed by the development of subretinal abscess in the contralateral eye. Finally, a diagnosis of endogenous Klebsiella endophthalmitis associated with prostatic abscess was made through a culture of the vitreous acquired by diagnostic vitrectomy. However, we could not save the vision of the left eye despite the intensive treatment with intravenous and intravitreal injections of antibiotics. ConclusionsRapidly progressive retinal vasculitis could be an initial sign of endogenous Klebsiella endophthalmitis even in an immunocompetent patient.

Risk factors for retinal microvascular impairment in type 2 diabetic patients without diabetic retinopathy

Objectives To determine the risk factors for retinal microvascular impairment on optical coherence tomography angiography (OCT-A) in type 2 diabetic patients without clinical diabetic retinopathy (DR). Methods This retrospective and cross-sectional study enrolled 74 diabetic patients without clinically evident DR for the study group and 34 healthy subjects for the control group. OCT-A parameters were measured to determine vascular density (VD) and the foveal avascular zone (FAZ) size in the superficial and deep capillary plexuses (SCP/DCP) of the retina. Clinical data were collected on sex, age, diabetes duration, hemoglobin A1c (HbA1c), hypertension, dyslipidemia, low-density lipoprotein cholesterol (LDL-C), estimated glomerular filtration rate (eGFR) and smoking status. Multiple linear regression analyses were performed to represent the associated clinical variables with OCT-A parameters in diabetic patients. Results In comparison between the study and control groups, the VD in the SCP and DCP were significantly lower in diabetic patients compared to the controls (P = 0.022 and 0.003, respectively). The FAZ size in the SCP and DCP were significantly greater in diabetic patients compared to the controls (P = 0.035 and <0.001, respectively). In age- and sex-adjusted multiple regression analyses for the diabetic patients, dyslipidemia and hypertension were negatively associated with SCP-VD (β = -0.357, P = 0.002; β = -0.239, P = 0.039, respectively). Current smoking was correlated with lower DCP-VD (β = -0.255, P = 0.043). Greater SCP-FAZ size was associated with dyslipidemia and greater LDL-C (β = 0.254, P = 0.013; β = 0.232, P = 0.029, respectively), and greater DCP-FAZ size, with lower eGFR and greater LDL-C (β = -0.355, P = 0.004; β = 0.235, P = 0.037, respectively). Conclusions Diabetic patients without clinical DR showed lower VD and greater FAZ size in the SCP and DCP compared to healthy controls. In diabetic patients without clinical DR, dyslipidemia and/or high LDL-C were important risk factors for retinal microvascular impairment. Hypertension, current smoking and lower eGFR also contributed to microvascular impairment.