https://scholarworks.korea.ac.kr/kumedicine/handle/2020.sw.kumedicine/250 Sat, 04 Apr 2026 15:19:36 GMT 2026-04-04T15:19:36Z https://scholarworks.korea.ac.kr/kumedicine/handle/2021.sw.kumedicine/64253 Title: Surgical time and efficacy of illuminated chopper-assisted cataract surgery involving miosis after femtosecond laser pretreatment Authors: Hwang, Sung Ha; Eom, Youngsub; Moon, Hyun Seung; Nam, Dong Heun Abstract: Purpose: To evaluate the efficacy of the illuminated chopper-assisted cataract surgery in terms of shortening the surgical time in eyes with miosis after femtosecond laser pretreatment. Methods: As retrospective study, three hundred thirty-six eyes of 336 consecutive patients who underwent the femtosecond laser and illuminated chopper-assisted cataract surgery were included. Cases with pupil less than 6 mm after femtosecond laser pretreatment were included in the miosis group. Pupil diameter, surgical time, and improved efficacy (100/surgical timexpupil size) were compared between eyes with and without miosis. Results: Of 336 eyes, 20 were included in the miosis group (6.0%). Pupil diameter was smaller in eyes with miosis than in those without miosis (5.23 +/- 0.38 mm vs 7.35 +/- 0.64 mm, p < 0.001); however, surgical time was not different (6.86 +/- 0.73 min vs 6.60 +/- 1.27 min, p=0.071) between the two groups. Mechanical pupil dilations were not needed in any cases. As a result, improved efficacy was calculated to be higher in patients with miosis (2.83 vs 2.14, p < 0.001). Conclusion: In terms of surgical time and improved efficacy, using the illuminated chopper simplified cataract surgery involving miosis after femtosecond laser pretreatment. The use of an illuminated chopper is expected to be a good solution for femtosecond laser-assisted cataract surgeries. Fri, 01 Mar 2024 00:00:00 GMT https://scholarworks.korea.ac.kr/kumedicine/handle/2021.sw.kumedicine/64253 2024-03-01T00:00:00Z https://scholarworks.korea.ac.kr/kumedicine/handle/2021.sw.kumedicine/64073 Title: A Low-Stimulus-Scattering Pixel-Sharing Sub-Retinal Prosthesis SoC With Time-Based Photodiode Sensing and Per-Pixel Dynamic Voltage Scaling Authors: Eom, Kyeongho; Park, Minju; Lee, Han-Sol; Ku, Seung-Beom; Kim, Namju; Cha, Seongkwang; Goo, Yong Sook; Kim, Sohee; Kim, Seong-Woo; Lee, Hyung-Min Abstract: This article proposes a 505-channel pixel-sharing sub-retinal prosthesis (PSRP) system-on-chip (SoC) that aims to effectively restore patients' visual acuity using the modular active/return electrode (Mod-A/R) scheme to mitigate current scattering and time-based photodiode (T-PD) sensing to increase the dynamic range (DR) of light sensing. To improve stimulation efficiency, the PSRP SoC adopts per-pixel dynamic voltage scaling (DVS) that can adaptively select different optimal supply voltages for each pixel. The proposed PSRP SoC has a small area of 0.01 mm(2) per pixel, while the Mod-A/R scheme reduces the current scattering by up to 95.4%. By combining five pixels into a single structure, the five-pixel sharing set can accommodate the T-PD sensor and the per-pixel DVS. The proposed T-PD sensor with internal clock modulation can detect the light in the range of 0.13-19 klux with a DR of 35.8 dB, while the per-pixel DVS reduces stimulation energy consumption by up to 64%. The PSRP SoC coated with sputtered iridium oxide film (SIROF) electrode can be applied to clinical trials by adapting the light detection range and stimulus intensity with 44-bit external control. Ex vivo experiments with retinal samples of mice have verified the effectiveness of the PSRP SoC. Wed, 01 Nov 2023 00:00:00 GMT https://scholarworks.korea.ac.kr/kumedicine/handle/2021.sw.kumedicine/64073 2023-11-01T00:00:00Z https://scholarworks.korea.ac.kr/kumedicine/handle/2021.sw.kumedicine/64300 Title: Comparison of RCI001 and corticosteroid on the effects on intraocular pressure in mice Authors: Kim, Soo Hyun; Ku, Young-ah; Yoo, Chungkwon; Kim, Yong Ho; Kim, Dong Hyun Abstract: PurposeRCI001, a novel therapeutic candidate for the treatment of ocular inflammatory diseases, have demonstrated remarkable anti-inflammatory and antioxidant effects in various ocular experimental models. This study was to evaluate the effects of RCI001 on intraocular pressure (IOP) and compare them with those of corticosteroids in experimental mouse models.MethodsExperimental mice were randomly divided into naive, phosphate-buffered saline (PBS), 0.1% dexamethasone (DEX-1), and 1% RCI001 (RCI) groups, and each reagent was pipetted into the right eye of the mouse at 10 mu L thrice daily for 5 weeks. In addition, 20 mu L of 0.1% dexamethasone was injected subconjunctivally into the right eye once weekly for 5 weeks in the DEX-2 group. The IOP was measured under anesthesia at baseline and twice weekly for 5 weeks. The oIOP (%) was defined as the change in IOP from baseline [oIOP (%) = (IOPweek5-IOPbaseline)/IOPbaseline x 100%]. The anterior segments were clinically and histologically examined.ResultsThere was no significant increase in IOP and oIOP (%) [values by week 3 (day 21) in any of the groups]. However, IOP and oIOP (%) in the DEX-2 group tended to increase slightly after day 10 compared with baseline. Compared with baseline IOP values, the DEX-1 group showed a statistically significant increase in IOP at weeks 4 and 5, and the DEX-2 group at week 5. The oIOP (%) of the DEX-1 and DEX-2 groups (%) at week 5 were 38.2% +/- 5.8% and 38.4 +/- 4.6%, respectively. However, the IOP in the RCI group did not increase significantly until week 5. The RCI group did not show notable corneal changes, such as epithelial defects or stromal opacities, at week 5. In addition, hematoxylin and eosin (H&E) staining of corneas in the RCI group revealed healthy corneal epithelial, stromal, and endothelial integrity.ConclusionLong-term use of RCI001 did not induce significant IOP elevation or ocular surface changes, whereas topical corticosteroids significantly increased the IOP. Therefore, RCI001 may be an effective anti-inflammatory agent with a low risk of drug-induced IOP elevation. Sun, 01 Oct 2023 00:00:00 GMT https://scholarworks.korea.ac.kr/kumedicine/handle/2021.sw.kumedicine/64300 2023-10-01T00:00:00Z https://scholarworks.korea.ac.kr/kumedicine/handle/2021.sw.kumedicine/64404 Title: The Variation of Electrical Pulse Duration Elicits Reliable Network-Mediated Responses of Retinal Ganglion Cells in Normal, Not in Degenerate Primate Retinas Authors: Cha, Seongkwang; Ahn, Jungryul; Kim, Seong-Woo; Choi, Kwang-Eon; Yoo, Yongseok; Eom, Heejong; Shin, Donggwan; Goo, Yong Sook Abstract: This study aims to investigate the efficacy of electrical stimulation by comparing network-mediated RGC responses in normal and degenerate retinas using a N-methyl-N-nitrosourea (MNU)-induced non-human primate (NHPs) retinitis pigmentosa (RP) model. Adult cynomolgus monkeys were used for normal and outer retinal degeneration (RD) induced by MNU. The network-mediated RGC responses were recorded from the peripheral retina mounted on an 8 x 8 multielectrode array (MEA). The amplitude and duration of biphasic current pulses were modulated from 1 to 50 mu A and 500 to 4000 mu s, respectively. The threshold charge density for eliciting a network-mediated RGC response was higher in the RD monkeys than in the normal monkeys (1.47 +/- 0.13 mC/cm(2) vs. 1.06 +/- 0.09 mC/cm(2), p < 0.05) at a 500 mu s pulse duration. The monkeys required a higher charge density than rodents among the RD models (monkeys; 1.47 +/- 0.13 mC/cm(2), mouse; 1.04 +/- 0.09 mC/cm(2), and rat; 1.16 +/- 0.16 mC/cm(2), p < 0.01). Increasing the pulse amplitude and pulse duration elicited more RGC spikes in the normal primate retinas. However, only pulse amplitude variation elicited more RGC spikes in degenerate primate retinas. Therefore, the pulse strategy for primate RD retinas should be optimized, eventually contributing to retinal prosthetics. Given that RD NHP RGCs are not sensitive to pulse duration, using shorter pulses may potentially be a more charge-effective approach for retinal prosthetics. Sun, 01 Oct 2023 00:00:00 GMT https://scholarworks.korea.ac.kr/kumedicine/handle/2021.sw.kumedicine/64404 2023-10-01T00:00:00Z