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Purpose: To derive the optimized intraocular lens (IOL) constants from automated and manifest refraction after cataract surgery in Korean patients, and to evaluate whether there is a difference in optimized IOL constants according to the refraction method.Methods: This retrospective multicenter cohort study enrolled 4,103 eyes of 4,103 patients who underwent phacoemulsification and in-the-bag IOL implantation at 18 institutes. Optimized IOL constants for the SRK/T, Holladay, Hoffer Q, and Haigis formulas were calculated via autorefraction or manifest refraction of samples using the same biometry and IOL. The IOL constants derived from autorefraction and manifest refraction were compared.Results: Of the 4,103 eyes, the majority (62.9%) were measured with an IOLMaster 500 followed by an IOLMaster 700 (15.2%). A total of 33 types of IOLs were used, and the Tecnis ZCB00 was the most frequently used (53.0%). There was no statistically significant difference in IOL constants derived from autorefraction and manifest refraction when IOL constants were optimized with a large number of study subjects. On the other hand, optimized IOL constants derived from autorefraction were significantly smaller than those from manifest refraction when the number of subjects was small.Conclusions: It became possible to use the IOL constants optimized from Koreans to calculate the IOL power. However, if the IOL constant is optimized using autorefraction in a small sample group, the IOL constant tends to be small, which may lead to refractive error after surgery.

Purpose: To report the effect of removal of a central descemet membrane on the endothelial function, morphology, and clinical symptoms of eyes with Fuch’s endothelial dystrophy.Methods: From August 2019 to January 2021, patients with Fuch’s endothelial dystrophy, i.e., with confluent, central corneal guttae and cataracts that required surgery, underwent phacoemulsification, intraocular lens implantation, and central descemet membrane stripping. To evaluate the effect of descemet stripping only (DSO), visual acuity and intraocular pressure were measured, and corneal pachymetry, slit-lamp and specular microscopy, and anterior segment optical coherence tomography performed, before surgery and at 1, 7, and 30 days and 3 and 6 months after surgery.Results: Seven patients (10 eyes) were included. Visual acuity improved from 1.01 ± 0.40 logarithm of the minimum angle of resolution (logMAR) preoperatively to 0.33 ± 0.22 logMAR 6 months after surgery (p = 0.008). The mean central corneal thickness decreased from 578.50 ± 36.88 μm preoperatively to 568.50 ± 48.61 μm 6 months after surgery; the difference was not significant (p = 0.507). The endothelial cell count increased significantly from 663.80 ± 356.40/mm2 preoperatively to 1,082.00 ± 274.46/mm2 6 months after surgery (p = 0.043).Conclusions: DSO can serve as a useful alternative when corneal transplantation is not possible in patients with Fuch’s endothelial dystrophy, but treatment efficacy and safety require further evaluation.

Purpose: To analyze the change in the weekly incidence of epidemic keratoconjunctivitis (EKC) per 1,000 outpatients during the coronavirus disease 2019 (COVID-19) pandemic by comparing the mean weekly proportion of EKC of 2020 with that from 2016 to 2019.Methods: Using data from the Korea Disease Control and Prevention Agency for 2016-2020, we analyzed the weekly proportion of EKC per 1,000 outpatients. The data were also analyzed according to age, semester and vacation periods, region, and social distancing stages. For the Daegu data, we also analyzed the effects of social distancing in an area.Results: The mean weekly proportion of EKC per 1,000 outpatients in 2020 was lower than in previous years for all ages (2016-2019 19.77 ± 7.17‰, 2020 7.28 ± 2.97‰; p < 0.001). During the semester, the mean difference between 2016-2019 and 2020 was significant, particularly for preschool children. In Daegu, the weekly proportion of EKC per 1,000 outpatients during the extra 12-18 weeks of social distancing was significantly lower (2016-2019, 18.78 ± 6.61‰; 2020, 8.94 ± 2.92‰; p < 0.001).Conclusions: The public health interventions implemented during the COVID-19 outbreak not only reduced the prevalence of COVID-19 but also reduced the prevalence of EKC. Therefore, maintaining hygiene principles and standard precautions may help prevent EKC.

Continuous detection of raised intraocular pressure (IOP) could benefit the monitoring of patients with glaucoma. Current contact lenses with embedded sensors for measuring IOP are rigid, bulky, partially block vision or are insufficiently sensitive. Here, we report the design and testing in volunteers of a soft and transparent contact lens for the quantitative monitoring of IOP in real time using a smartphone. The contact lens incorporates a strain sensor, a wireless antenna, capacitors, resistors, stretchable metal interconnects and an integrated circuit for wireless communication. In rabbits, the lens provided measurements that match those of a commercial tonometer. In ten human participants, the lens proved to be safe, and reliably provided accurate quantitative measurements of IOP without inducing inflammation.

In corneal transplantation, 16 submillimeter-sized sutures are generated around the circular-shaped graft cornea. A major challenge in corneal transplantation is the generation of uniformly shaped sutures, where the suture shapes need to be changed depending on the patient. In this study, a corneal suturing robot that can produce sutures of the desired shape with high uniformity is described. The proposed robot manipulates the corneal tissue deformation before inserting the needle for suture shape control. A simulation using the finite element method was proposed to predict the suture shape. The suturing experiment was conducted on a porcine model, and the result was compared with the simulation. As a result, the proposed robot was able to generate sutures with a standard deviation of 108 $\mu$ m in length and 36 $\mu$ m in depth. The mean absolute error between the simulation and the experiment was 95 $\mu$ m in length and 31 $\mu$ m in depth. This is the first study to suggest a method for controlling the suture shape and quantitatively analyzing it in ophthalmic surgery.

In this study, we investigated which greenhouse gas (GHG) emission sources have contributed to worsening global warming and which GHG mitigation efforts have been effective and finally evaluated th...

Müller cells are the principal glial cells for the maintenance of structural stability and metabolic homeostasis in the human retina. Although various in vitro experiments using two-dimensional (2D) monolayer cell cultures have been performed, the results provided only limited results because of the lack of 3D structural environment and different cellular morphology. We studied a Müller cell-based 3D biomimetic model for use in experiments on the in vivo-like functions of Müller cells within the sensory retina. Isolated primary Müller cells were bioprinted and a 3D-aligned architecture was induced, which aligned Müller cell structure in retinal tissue. The stereographic and functional characteristics of the biomimetic model were investigated and compared to those of the conventional 2D cultured group. The results showed the potential to generate Müller cell-based biomimetic models with characteristic morphological features such as endfeet, soma, and microvilli. Especially, the 3D Müller cell model under hyperglycemic conditions showed similar responses as observed in the in vivo diabetic model with retinal changes, whereas the conventional 2D cultured group showed different cytokine and growth factor secretions. These results show that our study is a first step toward providing advanced tools to investigate the in vivo function of Müller cells and to develop complete 3D models of the vertebrate retina.

본 연구에서는 경력정체의 결과 경력만족과 이직의도에 미치는 영향관계와 경력정체에 따라 자원상실이 예상되며, 상실된 자원을 줄일 수 있는 개인 내부자원으로서 긍정심리자본을 제시하여 긍정심리자본이 경력정체가 이직의도에 미치는 영향에 있어 조절효과를 검증하고자 한다. 실증분석 결과 다음과 같은 결과가 도출되었다. 첫째, 경력정체에 있어 내용적 경력정체, 구조적 경력정체 순으로 높게 지각할수록 경력만족이 낮아지는 것으로 나타났다. 이에 호텔기업에서는 종사원들이 경력정체를 지각하지 않도록 노력을 해야 할 것이다. 특히 조직차원에 대한 지원도 중요하지만 가장 중요한 것은 개인적으로 경력정체를 지각하지 않도록 노력을 해야 할 것이다. 둘째, 경력정체에 있어 내용적 경력정체, 구조적 경력정체 순으로 높게 지각할수록 이직의도가 높아지는 것으로 나타났다. 이에 개인차원에서 경력계획을 세우는 것이 중요하며, 조직차원에서는 조직에서는 직무체계의 개선, 교육훈련, 평가, 보상체계의 개선 등 인사관리시스템 전반의 개선이 필요하다. 셋째, 경력만족에 대해 높게 지각할수록 이직의도가 낮아지는 것으로 나타났다. 이에 조직 내부의 직무 관련 교육훈련 프로그램뿐만 아니라, 조직 외부의 전문 기관을 통한 직무 또는 비 직무 관련 교육 기회를 제공하여 개인의 경력에 대한 만족도를 높일 수 있도록 하여야 할 것이다. 넷째, 구조적 경력정체에 대해 높게 지각하더라도 낙관주의와 희망이 높으면 이직의도가 낮아지는 것으로 나타났다. 따라서 우수한 인적자원을 관리해야 하는 기업입장에서는 종사원들의 이직의도를 낮추기 위해 종사원들의 희망과 낙관주의를 높이기 위한 노력을 해야 할 것이다. 마지막으로 경력정체와 이직의도를 낮추기 위해서는 유연근무제, 재택근무제, 원격 근무 및 안식년 등의 제도 도입을 통하여 구성원들이 학습을 위한 시간을 할애하고 궁극적으로 일과 삶의 균형을 꾀할 수 있도록 돕는 것이 중요하다. 이는 점차 개인들은 자신의 직업을 통한 흥미 및 일과 삶의 균형을 추구하고 있기 때문이다.

In penetrating keratoplasty (PKP), the proper corneal suture placement is very important for successful transplantation and restoring functional vision. Generating sutures with accurate depth is difficult for the surgeon because of the tissue’s softness, lack of depth information, and hand tremors. In this paper, an automatic cornea grasping device is proposed, which detects when the device reaches the target suture depth. When the device reaches the target depth, the device rapidly grasps the cornea to prevent error induced by human hand tremors. In the paper, the performance of the proposed sensor, the actuator, and the device are experimentally verified with ex vivo experiment. The result showed that the proposed device could enhance the accuracy and precision of the corneal suture depth.

Significance Multimodal imaging based on optics and ultrasound can provide guide images and complementary structural and functional information, thus improving the accuracy of medical diagnosis and treatment monitoring. However, because conventional ultrasound transducers are opaque, in multimodal imaging with optics, the optical devices must be placed off-axis from the ultrasound transducer. This off-axis arrangement is prone to misalignment, adds complexity and bulk to the system, and can result in a low signal-to-noise-ratio. Here, we present a transparent ultrasound transducer at the heart of a quadruple fusion imaging system that seamlessly integrates ultrasound imaging, photoacoustic imaging, optical coherence tomography, and fluorescence imaging, and we demonstrate the system’s use in imaging responses to both ophthalmologic injuries and oncologic diseases., Ultrasound and optical imagers are used widely in a variety of biological and medical applications. In particular, multimodal implementations combining light and sound have been actively investigated to improve imaging quality. However, the integration of optical sensors with opaque ultrasound transducers suffers from low signal-to-noise ratios, high complexity, and bulky form factors, significantly limiting its applications. Here, we demonstrate a quadruple fusion imaging system using a spherically focused transparent ultrasound transducer that enables seamless integration of ultrasound imaging with photoacoustic imaging, optical coherence tomography, and fluorescence imaging. As a first application, we comprehensively monitored multiparametric responses to chemical and suture injuries in rats’ eyes in vivo, such as corneal neovascularization, structural changes, cataracts, and inflammation. As a second application, we successfully performed multimodal imaging of tumors in vivo, visualizing melanomas without using labels and visualizing 4T1 mammary carcinomas using PEGylated gold nanorods. We strongly believe that the seamlessly integrated multimodal system can be used not only in ophthalmology and oncology but also in other healthcare applications with broad impact and interest.

Integration of a smart contact lens and a heat patch realizes personal management of ocular surface diseases wirelessly., Wearable electronic devices that can monitor physiological signals of the human body to provide biomedical information have been drawing extensive interests for sustainable personal health management. Here, we report a human pilot trial of a soft, smart contact lens and a skin-attachable therapeutic device for wireless monitoring and therapy of chronic ocular surface inflammation (OSI). As a diagnostic device, this smart contact lens enables real-time measurement of the concentration of matrix metalloproteinase-9, a biomarker for OSI, in tears using a graphene field-effect transistor. As a therapeutic device, we also fabricated a stretchable and transparent heat patch attachable on the human eyelid conformably. Both diagnostic and therapeutic devices can be incorporated using a smartphone for their wireless communications, thereby achieving instantaneous diagnosis of OSI and automated hyperthermia treatments. Furthermore, in vivo tests using live animals and human subjects confirm their good biocompatibility and reliability as a noninvasive, mobile health care solution.

Multi-modal imaging technique has significantly spotlighted since it can provide a variety of information by combining the complementary merits of several single-modal imaging. In particular, in order to compensate for each shortcoming and improve image quality, an integrated optical and ultrasonic imaging system is being actively researched. However, the non-transparency of the ultrasound transducer made it difficult to integrate the optical and ultrasound imaging system. In previous study, we introduced the transparent ultrasound transducer (TUT) and dual-modal photoacoustic imaging (PAI)/ultrasound imaging (USI) system using the TUT. In this study, we present the multi-modal imaging system integrated with PA, US and optical coherence tomography (OCT). OCT has the advantage of acquiring anatomical information at optical resolution under subsurface and transparent media. To explore the usefulness of the multi-modal imaging system, we have successfully performed in vivo animal experiments: 1) eye imaging experiments and 2) subcutaneous melanoma imaging. In PAI, blood vessels and melanoma are clearly visualized. In OCT, the morphological information in shallow depth are observed in detail. In USI, the melanoma boundary and surrounding tissues are clearly confirmed. These results show that TUT based multi-modal imaging system can serve as a comprehensive in various applications.

Purpose To measure needle insertion force and change in intraocular pressure (IOP) in real-time during intravitreal injection (IVI). The effects of needle size, insertion speed, and injection rate to IOP change were investigated. Methods Needle insertion and fluid injection were performed on 90 porcine eyeballs using an automatic IVI device. The IVI conditions were divided according to needle sizes of 27-gauge (G), 30G, and 33G; insertion speeds of 1, 2, and 5 mm/s; and injection rates of 0.01, 0.02, and 0.05 mL/s. Insertion force and IOP were measured in real-time using a force sensor and a pressure transducer. Results The peak IOP was observed when the needle penetrated the sclera; the average IOP elevation was 96.3, 67.1, and 59.4 mmHg for 27G, 30G, and 33G needles, respectively. An increase in insertion speed caused IOP elevation at the moment of penetration, but this effect was reduced as needle size decreased: 109.8–85.9 mmHg in 27G for 5–1 mm/s (p = 0.0149) and 61.8–60.7 mmHg in 33G for 5–1 mm/s (p = 0.8979). Injection speed was also related to IOP elevation during the stage of drug injection: 16.65 and 11.78 mmHg for injection rates of 0.05 and 0.01 mL/s (p < 0.001). Conclusion The presented data offers an understanding of IOP changes during each step of IVI. Slow needle insertion can reduce IOP elevation when using a 27G needle. Further, the injection rate must be kept low to avoid IOP elevations during the injection stage.

PURPOSE We report the clinical efficacy of sequential applications of 0.3% and 0.15% unpreserved hyaluronic acid (HA) for the treatment of dry eye disease (DED). STUDY DESIGN Randomized clinical trial. METHODS Patients over 19 years of age with DED level 2 or higher, corneal fluorescein staining (CFS) score > 1, and tear break-up time (TBUT)

We present a multimodal imaging system that seamlessly integrates ultrasound imaging, photoacoustic imaging, and optical coherence tomography using a transparent ultrasonic transducer. We demonstrate the system’s use in imaging responses to mouse body in vivo.

To compare the efficacy of nonsteroidal anti-inflammatory drugs (NSAIDs) and steroidal eyedrops for inflammation management after cataract surgery using slitlamp indicators.11 eye centers in South Korea.Randomized prospective multicenter study with a blinded evaluator.In 125 (250 eyes) patients who underwent cataract surgery, bromfenac sodium hydrate 0.1% (NSAID group) was applied twice a day in 1 eye, whereas the other eye was treated with fluorometholone 0.1% (steroid group), 4 times a day for 4 weeks postoperatively. The primary efficacy outcome was the presence of anterior chamber cells and flare at 1 week postoperatively. Anterior chamber cells and flare at 4 to 8 weeks, corrected distance visual acuity, central corneal thickness, conjunctival hyperemia, dry eye parameters, foveal thickness, and ocular and visual discomfort were evaluated as secondary outcomes.At week 1, residual anterior chamber inflammation was not statistically significantly different between the groups (-1.03 ± 1.27 vs -0.95 ± 1.24, P = .4850). However, the NSAID group recovered from conjunctival hyperemia more rapidly than the steroid group (0.30 ± 0.52 vs 0.44 ± 0.81, P = .0144 at week 1). The increase in central corneal thickness in the NSAID group was less than that in the steroid group 1 week postoperatively (7.87 ± 22.46 vs 29.47 ± 46.60 μm, P.0001). The change in foveal thickness in the NSAID group was significantly less than that in the steroid group (18.11 ± 68.19 vs 22.25 ± 42.37 μm, P = .0002). Lower levels of postoperative ocular and visual discomfort were reported in the NSAID group than in the steroid group under treatment.Preservative-free bromfenac was as effective as preservative-free fluorometholone eyedrops in anterior chamber inflammation control and showed better signs and symptoms after cataract surgery.

Purpose To analyze the pathophysiological differences between patients with dry eye disease (DED) having different tear film break-up patterns (TBUPs). Methods This investigative analysis involved 91 eyes of 91 patients with DED who were divided into two groups: those with "dot" break-up pattern (group I) and those with "random" break-up pattern (group II). Clinical severity was evaluated using the Ocular Surface Disease Index (OSDI), Oxford stain score system (OSS) score, and tear film break-up time (TF-BUT). Eighteen patients in group I and 17 patients in group II were selected for sampling of tears and the conjunctiva, and the concentrations of inflammatory cytokines and mucin in the tears and conjunctival tissue were measured. Results Thirty-seven patients were classified as group I and 54 patients as group II. Patients in group I had a statistically lower TF-BUT and a higher OSS score than those in group II, whereas the OSDI was not statistically different between the groups. The concentrations of interleukin (IL)-6 and IL-8 were statistically higher in group I than those in group II. Impression cytology showed that the expression of IL-1β and IL-8 was higher in group I, whereas that of other genes was not statistically different. Conclusions We were able to clearly classify patients with DED with different TBUPs into two groups, and each group had different clinical and pathophysiological characteristics. In patients with the dot break-up pattern, the disease was strongly associated with ocular surface inflammation, as opposed to that in patients without this pattern.

Skin grafts are required in numerous clinical procedures, such as reconstruction after skin removal and correction of contracture or scarring after severe skin loss caused by burns, accidents, and trauma. The current standard for skin defect replacement procedures is the use of autologous skin grafts. However, donor-site tissue availability remains a major obstacle for the successful replacement of skin defects and often limits this option. The aim of this study is to effectively expand full thickness skin to clinically useful size using an automated skin reactor and evaluate auto grafting efficiency of the expanded skin using Yucatan female pigs. We developed an automated bioreactor system with the functions of real-time monitoring and remote-control, optimization of grip, and induction of skin porosity for effective tissue expansion. We evaluated the morphological, ultra-structural, and mechanical properties of the expanded skin before and after expansion using histology, immunohistochemistry, and tensile testing. We further carried out in vivo grafting study using Yucatan pigs to investigate the feasibility of this method in clinical application. The results showed an average expansion rate of 180%. The histological findings indicated that external expansion stimulated cellular activity in the isolated skin and resulted in successful grafting to the transplanted site. Specifically, hyperplasia did not appear at the auto-grafted site, and grafted skin appeared similar to normal skin. Furthermore, mechanical stimuli resulted in an increase in COL1A2 expression in a suitable environment. These findings provided insight on the potential of this expansion system in promoting dermal extracellular matrix synthesis in vitro. Conclusively, this newly developed smart skin bioreactor enabled effective skin expansion ex vivo and successful grafting in vivo in a pig model.