Nasolacrimal stent with shape memory as an advanced alternative to silicone products.

Epiphora is the overflow of tears typically caused by obstruction or occlusion of the nasolacrimal duct. More attention is required to address this global health issue owing to the increase in air pollution. Implantation of a silicone stent is the preferred treatment for epiphora; however, introducing a silicone stent into a narrow duct with complex geometry is challenging as it requires guidance by a sharp metal needle. Additionally, silicone can cause adverse reactions such as biofilm formation and tear flow resistance due to its extreme hydrophobicity. To overcome these problems, in this study we developed a new type of biocompatible shape memory polymer (SMP) stent with elasticity capacity for self-expansion. First, SMPs in the form of x%poly(ε-caprolactone)-co-y%poly(glycidyl methacrylate) (x%PCL-y%PGMA) were synthesized via ring opening polymerization by varying the molar ratio of PCL (x%) and PGMA (y%). Second, the shape memory and mechanical properties were tuned by controlling the crosslinking degree and concentration of x%PCL-y%PGMA solution to produce a test type of SMP stent. Lastly, this 94%PCL-06%PGMA stent exhibited more standout critical functions in a series of in vitro and in vivo experiments such as a cell growth-supporting level of biocompatibility with nasal epithelial cells without significant inflammatory responses, better resistance to biofilm formation, and more efficient capacity to drain tear than the silicone control. Overall, 94%PCL-06%PGMA can be suggested as a superior alternative to the currently used materials for nasolacrimal stents. STATEMENT OF SIGNIFICANCE: Silicone intubation (stenting) has been widely used to treat nasolacrimal duct obstruction, however, it can cause adverse clinical effects such as bacterial infection; presents procedural challenges because of the curved nasolacrimal duct structure; and shows poor drainage efficiency stemming from the highly hydrophobic nature of silicone. In this work, we describe an innovative shape memory polymer (SMP) as a superior alternative to conventional silicone-based materials for nasolacrimal duct intubation. We demonstrate the clear advantages of the SMP over conventional silicone, including a much higher drainage capacity and superior resistance to bacterial infection.

Effects of Orbital Decompression on Lamina Cribrosa Depth in Patients with Graves' Orbitopathy.

PURPOSE: We sought to investigate the effects of Graves' orbitopathy (GO) and orbital decompression on lamina cribrosa depth (LCD) using spectral-domain optical coherence tomography. METHODS: Forty eyes that underwent orbital decompression to relieve compressive optic neuropathy or correct disfiguring exophthalmos in the context of GO were included. Subjects were imaged with spectral-domain optical coherence tomography before surgery and at 1 and 3 months after surgery, at which the examiner measured the LCD (distance from the anterior surface of the lamina cribrosa to the Bruch membrane opening line) and peripapillary retinal nerve fiber layer thickness. Subjects were divided into two groups-a muscle-dominant group composed of patients who had extraocular muscle enlargement on preoperative orbital computed tomography scan and a fat-dominant group composed of patients who did not show extraocular muscle enlargement on preoperative orbital computed tomography scan-and subgroup analysis was performed. Preoperative and postoperative intraocular pressure, exophthalmos, LCD, and retinal nerve fiber layer thickness were evaluated. RESULTS: At baseline, LCD was remarkably shallower in the muscle-dominant group than in the fat-dominant group (95% confidence interval, p = 0.007). In the muscle-dominant group, LCD showed no definite change after surgery. However, the fat-dominant group showed temporary posterior displacement of the lamina cribrosa at 1-month postoperation that was reversed to baseline at 3 months postoperation (95% confidence interval, p < 0.01). CONCLUSIONS: The lamina cribrosa was anteriorly displaced preoperatively, and its position was nearly unchanged after the surgery, especially in association with extraocular muscle enlargement. An enlarged extraocular muscle could reduce the pressure-relieving effect of orbital decompression around the scleral canal in patients with GO.

Semiautomated fabrication of a custom orbital prosthesis with 3-dimensional printing technology.

The fabrication of orbital prostheses is complex and time-consuming. A virtual orbital prosthesis and its negative mold are presented by using a 3D printer. This method avoids damage to the soft tissue or patient discomfort and reduces the time and skill required to fabricate a custom orbital prosthesis.

Treatment of Exposed Hydroxyapatite Orbital Implants Wrapped with a Synthetic Dura Substitute.

PURPOSE: To describe cases of exposed hydroxyapatite (HA) implants wrapped with the synthetic dura substitute Neuro-Patch treated via simple Neuro-Patch removal. METHODS: The medical records of seven patients who experienced exposure of their HA implant were reviewed. All patients had been enucleated and implanted with HA wrapped with Neuro-Patch. For treatment, Neuro-Patch was removed to the greatest extent possible. After applying local anesthesia with lidocaine, blunt dissection was performed to separate the conjunctiva and Neuro-Patch via the site of exposure. Pressure was applied to the remaining Neuro-Patch with forceps and removed with scissors. RESULTS: Neuro-Patch was visible at the area of exposure in all patients. No surgery beyond initial Neuro-Patch removal was necessary in six of the seven patients. In five cases, the exposed area began to heal rapidly after Neuro-patch removal without primary closure of the defect. In one case, the Neuro-Patch material and all necrotic tissue was removed aggressively due to inflammation around the orbital implant. Lastly, an infection was noted in one case, prompting complete removal of the Neuro-Patch-wrapped HA implant. CONCLUSIONS: Wrapping material may hinder implant vascularization. Exposure of HA in wrapped implants can be successfully treated by a simple removal procedure if detected and managed early.

Comparison of the Clinical Manifestations between Acute Vogt-Koyanagi-Harada Disease and Acute Bilateral Central Serous Chorioretinopathy.

PURPOSE: To compare clinical, angiographic, and optical coherence tomographic characteristics between eyes with acute Vogt-Koyanagi-Harada (VKH) disease and eyes with acute bilateral central serous chorioretinopathy (CSC), and to demonstrate distinguishing features between the two diseases in confusing cases. METHODS: The medical records of 35 patients with VKH disease and 25 patients with bilateral CSC were retrospectively reviewed. Characteristics according to slit-lamp biomicroscopy, ophthalmoscopy, fundus photography, fluorescein angiography, indocyanine green angiography, and spectral-domain optical coherence tomography were compared between the two diseases. RESULTS: Five of 35 patients (10 of 70 eyes, 14.3%) with VKH disease were initially misdiagnosed as CSC patients, and six of 25 patients (12 of 50 eyes, 24%) with bilateral CSC were initially misdiagnosed as patients with VKH disease. Pigment epithelial detachment in CSC and optic disc hyperemia in VKH disease show the highest positive predictive values of 100% for each disease. CONCLUSIONS: Optic disc hyperemia in VKH disease and pigment epithelial detachment in bilateral CSC are the most specific clinical manifestations of each disease at initial patient presentation.