경도별 TPU 필라멘트의 3D 프린팅 압출 온도 조건에 따른 모폴로지 특성

정임주,신은주,이선희 한국섬유공학회 2022 한국섬유공학회지 Vol.59 No.1

Thermoplastic polyurethane (TPU) is used in various fields because of its excellentelasticity, flexibility, mechanical strength, and shock absorption. In particular, in the fuseddeposition modeling (FDM), in which layers are extruded by heating and melting thermoplasticmaterials through a nozzle, the adhesion and mechanical properties of theoutput are affected according to the nozzle temperature. In this study, six types of TPUfilaments with various hardnesses (65A, 75A, 80A, and 85A) were manufactured throughcommercial chip and synthesis (comp) and extruded under five nozzle temperature conditions(190 °C, 200 °C, 210 °C, 220 °C, and 230 °C). Then, the most suitable nozzle temperaturefor the filament was confirmed, and the re-entrant pattern was printed. Extrudedfilaments and printed re-entrant patterns were analyzed through morphology analysis. Finally, the tensile properties of the two samples of the optimal printed condition forFDM 3D printing were examined. Consequently, the optimal nozzle temperature of eachTPU filament was confirmed as 190 °C for Chip-65A, 210 °C for Chip-75A, 210 °C for Chip-80A, 200 °C for Chip-85A, 210 °C for Comp-75A, and 200 °C for Comp-85A. Through printingre-entrant patterns and morphologies, Chip-75A and Comp-75A were considered tobe the most suitable for 3D printing. The tensile properties showed that Chip-75A wasmore flexible than Comp-75A.

백내장 수술 후 발생한 음성 이상광시증의 임상 양상과 수술 만족도에 미치는 영향

김정아,하아늘,권지원,위원량,한영근,Jeong Ah Kim,MD,Ah Nul Ha,MD,Ji Won Kwon,MD,PhD,Won Ryang Wee,MD,PhD,Young Keun Han,MD,PhD 대한안과학회 2014 대한안과학회지 Vol.55 No.5

Purpose: To investigate the clinical characteristics of patients with pseudophakic negative dysphotopsia after cataract surgery and to analyze the risk factors of pseudophakic negative dysphotopsia as well as the postoperative effects on patient's satisfaction. Methods: This study included 1,020 eyes of 690 patients who underwent phacoemulsification and posterior chamber lens insertion between January 2010 and March 2012. Retrospective chart review was conducted to evaluate the prevalence of negative dysphotopsia according to the site of clear corneal incision during cataract surgery and the type of implanted intraocular lens (IOL). The clinical outcome of Neodymium:yttrium-aluminium-garnet (Nd:YAG) laser anterior capsulotomy in negative dysphotopsia patients was evaluated. Using a telephone survey, patients were asked to subjectively answer 18 questions regarding satisfaction after cataract surgery, the severity of visual symptoms and the effect of negative dysphotopsia in their daily life. Results: Negative dysphotopsia developed in patients who underwent uneventful cataract surgery and successful implantation of IOL in the bag. The patients' vision was corrected up to 20/20 (0.00 log MAR) and HVF P60-4 showed no abnormality in their visual field. There were significantly more patients with the SN60WF IOL who reported negative dysphotopsia but no other factors associated with the prevalence of negative dysphotopsia. During the telephone survey, patients complained of difficulties in their daily life related to the negative dysphotopsia symptoms and reported decreased satisfaction after cataract surgery. Conclusions: Although negative dysphotopsia can decrease the patient's satisfaction after cataract surgery, the genesis of negative dysphotopsia and an objective method to test for negative dysphotopsia is necessary. Therefore, a prospective large study should be conducted to evaluate the cause and treatment of negative dysphotopsia. J Korean Ophthalmol Soc 2014;55(5):669-678

유리체절제술 중 광각안저관찰렌즈에 발생하는 김서림 예방 방법의 비교

서명호,하아늘,이혜진,정진호,남기태 대한안과학회 2023 대한안과학회지 Vol.64 No.10

목적: 유리체절제술 중 광각안저관찰렌즈에 발생하는 김서림을 예방하기 위해 warm saline과 anti-fog solution을 이용한 방법의 효과를 비교하였다. 대상과 방법: 섭씨 36℃, 5 L의 물을 용기에 담고 광각안저관찰렌즈에 발생하는 김서림 영역을 현미경 영상으로 획득하였다. 렌즈를1분간 25℃의 sailne에 담근 군(control), 50℃의 sailne에 담근 군(warm saline), 25℃의 sailne에 담근 후 anti-fog solution을 도포한군(anti-fog)으로 나누었으며 각각 10초, 1분, 3분, 5분의 김서림 영역(%)과 렌즈 중심 영역 침범 유무를 확인하였다. 각 10회의 실험을반복하였다. 결과: Control군은 모든 실험 동안 100% 김서림 영역이 확인되었다. 10초, 1분, 3분, 5분의 평균 김서림 영역은 warm saline군이 4.34 ± 1.28%, 6.30 ± 1.38%, 56.00 ± 25.01%, 93.81 ± 5.88%, anti-fog군이 4.74 ± 0.57%, 7.35 ± 0.96%, 10.13 ± 1.09%, 11.74 ± 1.74%였고, 3분과 5분에서 유의한 차이를 보였다(p=0.029, p=0.012). Warm saline군은 3분과 5분 경과 후 각각 8예, 10예의 렌즈중심 영역 침범이 있었으며 anti-fog군은 관찰되지 않았다. 결론: Anti-fog solution을 광각안저관찰렌즈에 도포하는 방법은 유리체절제술 중 발생하는 김서림을 예방할 수 있다. Purpose: To compare the effectiveness of warm saline and anti-fog solution for preventing fogging of a non-contact wide-field viewing system during vitrectomy. Methods: Five liters of water at 36°C were placed in a transparent container. The fogging areas of wide-field lenses were microscopically measured. We created three groups: lenses soaked in normal saline at 25°C for 1 minute (control), lenses soaked in normal saline at 50°C for 1 minute (warm saline), and lenses that were wiped with a sponge soaked in anti-fog solution (ULTRASTOP pro med. Solution, Sigmapharm, Vienna, Austria) after prior soaking in normal saline at 25°C for 1 minute (anti-fog). Images of fogged areas were acquired at 10 seconds and 1, 3, and 5 minutes. Extent of fogged areas and central lens invasion were determined. All experiments were repeated 10 times. Results: In the control group, the entire areas were always completely fogged. The average fog coverage values were 4.34 ± 1.28, 6.30 ± 1.38, 56.00 ± 25.01, and 93.81 ± 5.88% at 10 seconds and 1, 3, and 5 minutes in the warm saline group and 4.74 ± 0.57, 7.35 ± 0.96, 10.13 ± 1.09, and 11.74 ± 1.74% in the anti-fog group, respectively. There were significant differences at 3 and 5 minutes (p = 0.029, p = 0.012). Fogging of the central lens was detected in 8 tests after 3 minutes and all 10 tests after 5 minutes in the warm saline group, but no fogging was detected in the anti-fog group. Conclusions: Application of an anti-fog solution to a wide-field viewing lens prevents lens fogging during vitrectomy.

큰 유두함몰비를 갖는 녹내장모양시신경유두와 원발개방각녹내장안 시신경유두함몰 깊이 비교

문용석(Yong Seok Mun),하아늘(Ah nul Ha,),정진욱(Jin Wook Jeoung),박기호(Ki Ho Park),김영국(Young Kook Kim) 대한안과학회 2018 대한안과학회지 Vol.59 No.6

목적: 녹내장에서 시신경유두 표면의 함몰이 관찰된다는 것은 선행연구를 통해 알려져 있다. 큰 유두함몰비를 가진 녹내장모양시신경 유두와 원발개방각녹내장안의 시신경유두 사이에서 평균 시신경유두함몰 깊이를 정량적으로 비교하고자 하였다. 대상과 방법: 본원 녹내장 외래에 내원한 환자 중 스펙트럼영역 빛간섭단층촬영(spectral domain optical coherence tomography)인 CirrusTM HD-OCT (Carl Zeiss Meditec, Inc., Dublin, CA, USA)를 사용하여 평균 유두함몰비, 유두영역, 시신경유두함몰부피를 측정한 환자들 중, 평균 유두함몰비가 0.7 이상 0.8 이하의 녹내장모양시신경유두 환자 40명 40안과 동일 조건의 유두함몰비를 보이는 원발개방각녹내장 환자 40명 40안을 대상으로 하였다. 다음 공식을 사용하여 각 군의 평균 시신경유두함몰 깊이를 계산하였다: (시신경유두함몰부피/[유두영역×평균유두함몰비2])–200 μm. 결과: 녹내장모양시신경유두 집단의 평균 나이는 61.18 ± 11.83세, 원발개방각녹내장 집단의 평균 나이는 59.65 ± 11.69세였으며, 평균 유두함몰비는 녹내장모양시신경유두 집단 0.74 ± 0.03, 원발개방각녹내장 집단 0.75 ± 0.03으로 두 군 간 차이가 없었다 (p=0.333, t-test). 그러나 평균 시신경유두함몰 깊이는 각각 144.74 ± 82.78 μm와 199.53 ± 90.26 μm로 원발개방각녹내장군에서 유의하게 컸다(p=0.006, t-test). 결론: 녹내장모양시신경유두는 비슷한 유두함몰비를 가지는 원발개방각녹내장 환자의 시신경유두와 비교하였을 때 유의하게 얕은 평균 시신경유두함몰 깊이를 보였다. 스펙트럼영역 빛간섭단층촬영 결과지를 바탕으로 평균 시신경유두함몰 깊이를 확인하는 것은 녹내장모양시신경유두를 녹내장성 시신경유두로부터 감별하는 데 추가적인 정보를 제공할 수 있을 것으로 기대된다. Purpose: Optic nerve head surface depression in patients with glaucoma has been previously reported. We quantitatively compared the mean optic disc cup surface depth between glaucoma-like disc (GLD) patients with large cup-to-disc ratios and primary open-angle glaucoma (POAG) patients. Methods: A total of 40 eyes of 40 patients with GLD and 40 eyes of 40 patients with POAG were included in this study. All patients had an average cup-to-disc ratio of 0.7–0.8. The optic disc area, mean cup-to-disc ratio, and mean optic disc cup volume were measured using spectral domain optical coherence tomography (Cirrus™ HD-OCT; Carl Zeiss Meditec, Inc., Dublin, CA, USA). The mean optic disc cup surface depth was calculated using the formula: (mean optic disc cup volume/[optic disc area × mean cup-to-disc ratio2]) – 200 μm. Results: The mean ages of patients were 61.18 ± 11.83 and 59.65 ± 11.69 years for the GLD and POAG groups, respectively. The average cup-to-disc ratios were 0.74 ± 0.03 and 0.75 ± 0.03 for the GLD and POAG groups, respectively, but no significant difference was observed between the two groups. The mean optic disc cup surface depths were 144.74 ± 82.78 μm and 199.53 ± 90.26 μm for the GLD and POAG groups, respectively, and the difference between the two groups was statistically significant (p = 0.006, t-test). Conclusions: POAG patients showed a significantly greater mean optic disc cup surface depth compared to GLD patients with a similar mean cup-to-disc ratio. Based on the results of spectral domain optical coherence tomography, confirming the mean optic disc cup surface depth is expected to provide additional information to distinguish GLD from POAG patients.

Comparison of Two Combinations of Maximum Medical Therapy for Lowering Intraocular Pressure in Primary Open-angle Glaucoma

위서영,김영국,정진욱,박기호,하아늘 대한안과학회 2020 Korean Journal of Ophthalmology Vol.34 No.1

Purpose: We sought to compare the efficacy as well as the safety of two maximum medical therapy combinationsapplied to lower the intraocular pressure (IOP) in different primary open-angle glaucoma (POAG) agegroups. Methods: This was a retrospective, consecutive case series study that included 60 eyes of 60 subjects withPOAG, specifically 20 subjects aged 40 to 54 years, 21 aged 55 to 69 years, and 19 aged 70 years or older. All had been treated for at least 12 months with triple maximum medical therapy (TMT; dorzolamide/timolol,brimonidine, and latanoprost) to lower their IOP, which subsequently was changed to double maximum medicaltherapy (DMT, fixed drug combinations of tafluprost/timolol and brinzolamide/brimonidine). The rate of IOPchange and adverse drug reactions were compared amongst the three age groups. Results: The mean IOP change at three months after converting from TMT to DMT was -0.65 ± 1.42 mmHg(-3.84% ± 9.31%) among the overall study group, but this finding was not statistically significant (p = 0.108). Inthe 40 to 54 years and 55 to 69 years groups, the mean IOP change rates were +0.29 ± 0.96 mmHg (+2.40%± 6.85%, p = 0.087) and -0.50 ± 0.99 mmHg (-3.05% ± 6.40%, p = 0.084) respectively. In the 70 years or oldergroup, the mean IOP change, interestingly, was -1.80 ± 1.46 mmHg (-11.29% ± 9.31%, p < 0.001) and nine (47.4%)of the 19 subjects showed additional IOP reductions of 10% or more after converting from TMT to DMT. In allthree age groups, the incidence rate of dry eye was significantly lower for DMT than for TMT (p = 0.031). Conclusions: In POAG patients, DMT was proven to be both effective and safe for lowering the IOP, especiallyin those 70 years or older group, when compared with the TMT protocol.

수기 수정체낭 원형절개술과 정밀 펄스에너지를 이용한 수정체낭 원형절개술의 임상 결과 비교 연구

지 만,이혜진,하아늘,남기태,정진호 대한안과학회 2023 대한안과학회지 Vol.64 No.11

목적: 일반적인 양안 백내장수술 환자에서 단안은 수기로 반대안은 정밀 펄스에너지를 이용한 수정체낭 원형절개를 시행하였을 때안전성 및 일관성을 비교하며 수술 후 임상 결과에 차이를 확인해보고자 하였다. 대상과 방법: 양안 백내장으로 진단받은 환자 101명을 대상으로 동일한 환자에서 양안 백내장수술 진행 시 단안은 정밀 펄스에너지를이용한 수정체낭 원형절개술을 시행하였고 반대안은 수기로 수정체낭 원형절개를 진행하였다. 전낭절개의 소요 시간, 크기 및 원형도를 측정하였고 수술 중 방사상 파열 등의 합병증 여부, 초음파 에너지, 수술 후 시력, 각막내피세포 수를 측정하여 두 군 간 독립표본t검정을 통해 비교하였다. 결과: 펄스에너지군과 수기군에서 전낭절개에 소요된 시간은 통계학적으로 유의한 차이가 없었다. 전낭절개의 크기는 펄스에너지군에서 통계적으로 유의하게 작았고 전낭절개의 원형도는 펄스에너지군에서 통계적으로 유의하게 높았다. 전낭절개 도중 합병증 발생은수기군에서 2건, 펄스에너지군에서는 없었으며 술 후 나안시력, 최대교정시력, 각막내피세포 수에는 두 군 사이에 유의한 차이가 없었다. 결론: 백내장수술 시 동일한 환자에서 양안을 수기 및 정밀 펄스에너지를 이용한 수정체낭 원형절개를 시행하였을 때 정밀 펄스에너지를 이용한 수정체낭 원형절개가 높은 원형도와 작은 수정체낭 원형절개 크기를 보였으며 수술 중 낮은 합병증 발생률을 보였다. 수술 후 임상 결과에서는 두 군 간 유의한 차이를 나타내지 않았다. Purpose: To compare the safety and consistency of manual capsulorhexis and precision pulse capsulotomy performed using pulsed energy during bilateral cataract surgery and to explore the differences in clinical outcomes. Methods: A total of 101 patients with bilateral cataracts were selected. Precision pulse capsulotomy was performed on one eye and manual continuous curvilinear capsulorhexis on the other. The independent-samples t-test was used to compare the duration of continuous curvilinear capsulorhexis, incisional size and roundness, complications such as radial tears, the cumulative dissipated energy, the visual acuity after surgery, and the corneal epithelial cell count. Results: There was no significant difference in the capsulorhexis time between the pulse energy and manual groups. The extent of capsulorhexis was significantly smaller and the circularity of capsulorhexis was higher in the former group. Complications occurred in two manual capsulorhexis patients but in no pulse energy capsulotomy patient. There was no significant between- group difference in any of postoperative visual acuity, best-corrected visual acuity, or the corneal endothelial cell count. Conclusions: During bilateral cataract surgery on the same patients, precision capsulotomy using pulse energy afforded smaller and more circular capsulorhexis and fewer complications than did manual capsulorhexis. However, there was no significant between- group difference in the postoperative clinical outcomes.

혼탁한 각막 후부에 숨겨져 있던 나무 가시에 의한 각막염 치료 사례

김성미(Seongmi Kim),이혜진(Hye Jin Lee),하아늘(Ahnul Ha),이종영(Jong Young Lee),정진호(Jinho Jeong) 대한안과학회 2021 대한안과학회지 Vol.62 No.12

목적: 전안부빛간섭단층촬영과 전방각경검사를 통해 혼탁한 각막 후부에서 발견된 나무 가시를 제거하고 각막염이 호전된 증례를 보고하고자 한다. 증례요약: 79세 여성이 농사 중 좌안을 가시에 찔린 후 발생한 각막염으로 한 달간 항생제 치료에도 호전이 없어 의뢰되었다. 좌안 시력은 안전수동이었고, 중심부에 각막혼탁과 함께 전방축농이 동반되었으며, 강화 항생제 점안치료에도 전방축농은 호전과 악화를 반복하였다. 각막병변부에 전안부빛간섭단층촬영 및 전방각경검사를 통해 후부 각막 및 전방 내로 돌출된 미세 이물을 확인하였으며, 수술적으로 제거하였다. 이물 제거 후 좌안 전방축농은 소실되었고, 각막혼탁과 상피결손이 호전되었다. 결론: 통상적인 치료로 호전되지 않는 감염각막염에서 외상의 병력이 있고 혼탁으로 인해 각막 후면이 관찰되지 않을 때, 각막내 이물의 잔존 가능성을 의심하여야 하며, 전안부빛간섭단층촬영 및 전방각경검사가 유용한 진단 도구로 활용될 수 있다. Purpose: We report a case of keratitis that improved after removal of a causative plant foreign body from below the posterior surface of an opaque cornea. The foreign body was revealed by anterior segment optical coherence tomography (AS-OCT) and gonioscopy. Case summary: A 79-year-old woman was referred with an impression of left-eye keratitis; the eye had been injured by a branch of a tangerine tree 1 month prior. She had been given the usual topical antibiotics by a local clinic, but they were ineffective. At her initial visit, her visual acuity was only hand motion in the left eye; slit-lamp examination revealed a 3 × 3-mm corneal infiltration with a hypopyon in the anterior chamber. Despite administration of strong topical antibiotics on an hourly basis, the corneal lesion worsened. AS-OCT and gonioscopy revealed a small foreign body below the posterior surface of the cornea; this was surgically removed. The corneal opacity and corneal epithelial defects dramatically improved, and the hypopyon disappeared. Conclusions: The possibility of a residual foreign body should be considered if trauma precedes infectious keratitis that does not improve with conventional treatment and the posterior surface of the cornea is not visible because of corneal opacity. In such a case, AS-OCT and gonioscopy can be useful.