비구면 인공수정체와 구면 인공수정체의 술 후 Nd:YAG 레이저 후낭절개술 시행률 비교

전익현,서경률,김응권,김태임,Ikhyun Jun,MD,Kyoung Yul Seo,MD,PhD,Eung Kweon Kim,MD,PhD,Tae Im Kim,MD,PhD 대한안과학회 2011 대한안과학회지 Vol.52 No.4

Purpose: The purpose of the present study is to compare Nd:YAG capsulotomy rates between spherical and aspheric intraocular lenses. Methods: The present retrospective study enrolled patients who received cataract surgery by a single surgeon between March 1, 2006 and October 31, 2009. Patients included in the study were implanted with SA60AT spherical intraocular lenses (Alcon, Fort Worth, TX, USA, 66 eyes), SN60AT spherical intraocular lenses (Alcon, 48 eyes; a total of 114 eyes), or SN60WF aspheric intraocular lenses (Alcon, 187 eyes). The Nd:YAG capsulotomy rates were compared between the two groups 6 months after the operation. Ten patients who were implanted with a spherical intraocular lens in one eye and an aspheric intraocular lens in the contralateral eye were analyzed separately. Results: Nd:YAG capsulotomy was performed in 2 of 114 eyes (1.8%) in the spherical intraocular lens group and 7 of 187 eyes (3.2%) in the aspheric intraocular lens group; no significant difference was found (p = 0.359). Among the 10 patients who were implanted with 2 different intraocular lenses, Nd:YAG capsulotomy was performed in only 1 eye in the aspheric intraocular lens group; no significant difference was found (p = 0.500). Conclusions: The design of the intraocular lens, especially the shape of the posterior optic, does not influence the rate of Nd:YAG capsulotomy. J Korean Ophthalmol Soc 2011;52(4):414-419

각막이식수술 후 동적 샤임플러그 분석 장비를 이용한 각막의 생역학적 특성 변화

박서진,전익현,서경률,김응권,김태임 대한안과학회 2020 대한안과학회지 Vol.61 No.6

Purpose: To evaluate the biomechanical properties of corneas using a dynamic Scheimpflug analyzer (Corvis ST) after penetrating keratoplasty (PKP) and Descemet’s membrane stripping keratoplasty (DSEK). Methods: The medical records of 11 eyes that had undergone PKP (PKP group) and 11 eyes that had undergone DSEK (DSEK group) from March 2017 to March 2018 and the results were compared with 20 eyes of the control group. All patients’ corneal biomechanical properties, including a deformation amplitude ratio of 2.0 mm (DA ratio 2.0 mm), integrated inverse radius (IntInvRad), stiffness parameter at first applanation (SP-A1), and Ambrosio relational thickness through the horizon meridian (ARTh) were measured and compared with those of the normal control group. In addition, biomechanically corrected intraocular pressure (bIOP) measured by the Corvis ST was compared with intraocular pressure measured by a Tono-Pen Applanation Tonometer (IOP-Tono-Pen). Results: In the PKP group, the biomechanical properties using the Corvis ST showed a significantly lower DA ratio 2.0 mm, SP-A1, ARTh, and IntInvRad, compared with those of the control group. However, in the DSEK group, only ARTh was significantly lower than that of the control group. Conclusions: Corvis ST can be used to measure the change of corneal biomechanical properties after corneal transplantation. 목적: 동적 샤임플러그 분석 장비(Corvis ST)를 이용하여 각막이식수술 후 각막의 생역학적 특성 변화를 평가하였다. 대상과 방법: 2017년 3월부터 2018년 3월까지 세브란스병원에서 전층각막이식술(penetrating keratoplasty, PKP)을 시행받은 11명, 11명의 데스메막박리 각막내피층판이식술(descemet’s membrane stripping keratoplasty, DSEK) 환자군을 20명의 대조군과 비교하였다. 변형진폭비 2.0 mm (deformation amplitude [DA] ratio 2.0 mm), 역반경의 합(integrated inverse radius, IntInvRad), 첫 압평시 강성매개변수(stiffness parameter at first applanation, SP-A1) 수평자오선을 통한 Ambrosio 관계형 두께(ambrosio relational thickness through the horizon meridian, ARTh), 중심각막두께 및 생역학적 보정안압(biomechanically corrected intraocular pressure)을 비교하였다. 결과: PKP를 시행 받은 환자군은 대조군에 비해 DA ratio 2.0 mm, SP-A1, ARTh, IntInvRad 모두 유의미하게 낮게 측정되었으나, DSEK을 시행 받은 환자군에서는 ARTh만 유의미한 차이를 나타내었다. 결론: Corvis ST를 이용하여 각막이식술 후 각막의 변화에 대해 측정할 수 있다.

DEA Approaches Applied to Lozano and Humphrey Model of Bank Efficiency

이장우,전익현 한국경영컨설팅학회 2015 경영컨설팅연구 Vol.15 No.1

We test and compare the efficiency of Korean domestic banks. There are a few economic points of view to banks efficiency that consider multiple inputs and multiple outputs. Among the theories of banks efficiency we choose Lozano and Humphrey Model of Bank Efficiency. DEA methods in the form of Super-efficiency Model and Malmquist productivity index are used for a test of ranking in efficiency and comparison of efficiency improvement. We compare the efficiency of Seoul-centered commercial banks and local banks in Korea from 2007 to 2013. Malmquist productivity index is used to analyze the trend of changes in the bank productivity. We find that Seoul-centered commercial banks are a little superior to local banks in efficiency, but the improvement of productivity along passage of time for local banks and Seoul-centered commercials are not significantly different. This result is different from that of operations approach, which shows that DEA analysis is sensitive to difference of approaches (Berg, 2010). Findings from operations approach (Shin et al., 2015) supports that local banks have more opportunities to harvest from pursuit of economy of scale. In addition, local banks are likely to have had relatively lower level of accumulated fixed costs due to shorter length of time of operation. Further, we document that bank's operating efficiency is likely to be more significantly influenced by external business environment than the bank's unique ability to utilize its internal resources.

토포라이저 바리오를 이용한 각막굴절력검사의 신뢰도 연구

설동헌,전익현,이형근,김응권,서경률,김태임 대한안과학회 2020 대한안과학회지 Vol.61 No.8

Purpose: To evaluate the clinical reliability of the Topolyzer Vario (Wavelight-Alcon, Erlangen, Germany), we compared three different corneal topographers in terms of corneal refractive power. Methods: The medical records of patients who visited Severance Hospital for corneal refractive surgery were retrospectively reviewed. Keratometric data of patients who underwent evaluations using the Pentacam HR (Oculus, Wetzlar, Germany), ORBscan II (Bausch & Lomb, Rochester, NY, USA), and Topolyzer Vario instruments on the same day were obtained. Flat keratometry (Kf), steep keratometry (Ks), mean keratometry (Km), astigmatism keratometry (Kastig), Cartesian astigmatism (J0), and oblique astigmatism (J45) values were calculated. The measurement values of the three devices were subjected to Pearson’s correlation analysis and repeated measures analysis of variance (with Bonferroni correction); a Bland-Altman plot was also created. Results: The keratometric data of 80 eyes were included in the analysis and all of the keratometric measurements obtained by the three devices showed significant correlations, i.e., good agreement. The Kf and Km measurements of the Pentacam HR were flatter than those of the ORBscan II, and the Kf, Km, Ks, and J45 measurements were flatter than those of the Topolyzer Vario. However, there was no significant difference in keratometric values between the ORBscan II and Topolyzer Vario. Furthermore, the difference in corneal refractive power between the Pentacam HR and Topolyzer Vario was not clinically significant. Conclusions: When measuring the corneal refractive power of patients without any history of corneal disorder or ocular surgery, the Topolyzer Vario is a clinically reliable device that shows similar performance to the ORBscan II and Pentacam HR. 목적: Topolyzer Vario (WaveLight, Erlangen, Germany)의 임상적 신뢰도에 대하여 평가하기 위하여 각막지형도를 검사하는 세 기기의 각막굴절력 측정값을 비교하였다. 대상과 방법: 각막굴절교정술을 위해 본원에 내원한 환자들의 의무기록을 후향적으로 분석하여, Pentacam HR (Oculus, Wetzlar, Germany), ORBscan II (Bausch & Lomb, Rochester, New York, USA), Topolyzer Vario를 동일한 날에 시행한 환자들의 각막계측치를 분석하였다. 각 기기로부터 편평각막곡률(Kf), 가파른각막곡률(Ks), 평균각막곡률(Km)과 난시값(Kastig), 카티지언 난시(J0), 경사난시(J45)를 계산하여 비교하였다. 결과: 80안의 각막계측치를 분석하였으며, 세 기기들은 모든 각막굴절력값에서 높은 상관성과 일치도를 보였다. Pentacam HR은 ORBscan II보다 Kf, Km을 유의하게 낮게 측정하였고, Topolyzer Vario보다 Kf, Km, Ks, J45를 유의하게 낮은 수준으로 측정하였으나, ORBscan II와 Topolyzer Vario 간에는 모든 측정값에서 유의한 차이가 관찰되지 않았다. Topolyzer Vario와 Pentacam HR 간 측정된 각막굴절력값의 차이는 임상적 의미가 크지 않았다. 결론: 굴절이상 외 다른 안과적 과거력이 없는 환자의 각막굴절력 측정시, Topolyzer Vario는 ORBscan II 및 Pentacam HR과 호환이 가능하므로 임상적으로 신뢰할 만한 검사기기이다.

Clinical Outcomes of Small Incision Lenticule Extraction in Myopia: Study of Vector Parameters and Corneal Aberrations

곽지용,전익현,김응권,서경률,김태임 대한안과학회 2020 Korean Journal of Ophthalmology Vol.34 No.1

Purpose: To investigate clinical outcomes of small incision lenticule extraction (SMILE) including vector parametersand corneal aberrations in myopic patients. Methods: This retrospective, observational case series included 57 eyes (29 patients) that received treatmentfor myopia using SMILE. Visual acuity measurement, manifest refraction, slit-lamp examination, autokeratometry,corneal topography, and evaluation of corneal wavefront aberration were performed preoperatively and at1 and 3 months after surgery. We analyzed the safety, efficacy, vector parameters, and corneal aberrations at3 months after surgery. Results: Preoperatively, mean manifest refraction spherical equivalent refraction was -4.94 ± 1.94 D (range,-8.25 to 0 diopters [D]), and the cylinder was -1.14 ± 0.82 D (range, -3 to 0 D). Mean manifest refraction sphericalequivalent improved to -0.10 ± 0.23 D at 3 months postoperatively, when uncorrected distance visual acuitywas 20 / 20 or better in 55 (96%) eyes. The linear regression model of target induced astigmatism vectorversus surgically induced astigmatism vector exhibited slopes and coefficients (R2) of 0.9618 and 0.9748, respectively(y = 0.9618x + 0.0006, R2 = 0.9748). While total corneal root mean square higher order aberrations,coma and trefoil showed statistically significant increase, spherical aberration did not show statistically significantchange after SMILE. Conclusions: SMILE has proven to be effective and safe for correcting myopia and astigmatism. We showedthat SMILE did not induce spherical aberrations. A small increase in postoperative corneal higher order aberrationmay be associated with increase in coma and trefoil.

Accuracy of the Kane Formula for Intraocular Lens Power Calculation in Comparison with Existing Formulas: A Retrospective Review

류소영,전익현,김태임,김응권,서경률 연세대학교의과대학 2021 Yonsei medical journal Vol.62 No.12

Purpose: To evaluate the accuracy of the Kane formula for intraocular lens (IOL) power calculation in comparison with existing formulas by incorporating optional variables into calculation. Materials and Methods: This retrospective review consisted of 78 eyes of patients who had undergone uneventful phacoemulsification with intraocular implantation at Severance Hospital in Seoul, Korea between February 2020 and January 2021. The Kane formula was compared with six of the existing IOL formulas (SRK/T, Hoffer-Q, Haigis, Holladay1, Holladay2, Barrett Universal II) based on the mean absolute error (MAE), median absolute error (MedAE), and the percentages of eyes within prediction errors of ±0.25D, ±0.50D, and ±1.00D. Results: The Barrett Universal II formula demonstrated the lowest MAEs (0.26±0.17D), MedAEs (0.28D), and percentage of eyes within prediction errors of ±0.25D, ± 0.50D, and ±1.00D, although there was no statistically significant difference between Barrett Universal II-SRK/T (p=0.06), and Barrett Universal II-Kane formula (p<0.51). Following the Barrett Universal II formula, the Kane formula demonstrated the second most accurate formula with MAEs (0.30±0.19D) and MedAEs (0.28D). However, no statistical difference was shown between Kane-Barrett Universal II (p=0.51) and Kane-SRK/T (p=0.14). Conclusion: Although slightly better refractory outcome was noted in the Barrett Universal II formula, the performance of the Kane formula in refractive prediction was comparable in IOL power calculation, marking its superiority over many conventional IOL formulas, such as HofferQ, Haigis, Holladay1, and Holladay2.

마이봄선기능장애 환자에서 안검미세각질제거의 임상효과

변형주,전익현,서경률,김응권,김태임 대한안과학회 2020 대한안과학회지 Vol.61 No.6

Purpose: To assess the clinical efficacy of microblepharoexfolication using BlephEx™ (Scope Ophthalmics, London, UK) in meibomian gland dysfunction (MGD) patients. Methods: We performed a prospective study involving 48 eyes of 24 patients who were diagnosed with MGD. All patients were treated with BlephEx™ for 8-10 minutes, and the ocular surface disease index (OSDI), tear break-up time (TBUT), Schirmer’s I test, corneal staining score, lid margin abnormality, MGD score, and lipid thickness layer using the Lipiview II (TearScience, Morrisville, NC, USA) were assessed before treatment and after one month. Results: Significant changes were observed after microblepharoexfoliation using BlephEx™. The TBUT improved from 2.65 ± 1.16 to 3.77 ± 1.80 after 1 month (p < 0.001) and the OSDI improved from 38.83 ± 17.13 to 18.67 ± 15.01 after 1 month (p < 0.001). Before and after 1 month of treatment, the lid margin abnormalities were 2.98 ± 1.16 and 2.50 ± 1.01 (p < 0.001) and the MGD scores were 21.60 ± 6.95 and 18.02 ± 6.68 (p = 0.001), respectively. Conclusions: BlephEx™ improved the patients’ ocular surface symptoms, MGD score, and TBUT. Using steroid eye drops, there was a synergistic effect in improvement. Therefore, using BlephEx™ may be suggested as a treatment option for MGD patients. 목적: 마이봄선기능장애(MGD)환자에서 BlephExTM (Scope Ophthalmics, London, UK)를 이용한 안검미세각질제거 후의 임상적 효과를 객관적 수치를 통해 알아보고자 한다. 대상과 방법: 2018년 10월부터 11월까지 세브란스병원에서 MGD로 진단받은 24명의 양안에 대하여 8-10분간 BlephExTM를 시행하였으며 이들의 안구표면질환지수(OSDI), 눈물막파괴검사, 쉬르머 검사, 각막염색지수, 눈꺼풀 경계 이상, 마이봄선기능장애정도와 Lipiview II 간섭계(TearScience Inc., Morrisville, NC, USA)를 통한 눈물지질층두께를 치료 전과 치료 후 1개월째에 조사하여 비교하였다. 결과: BlephExTM 사용 시 눈물층파괴시간은 치료 전 2.65 ± 1.16초에서 치료 1달 후 3.77 ± 1.80초로 유의미하게 증가하였다(p<0.001). 눈꺼풀 경계 이상은 치료 전 2.98 ± 1.16점에서 2.50 ± 1.01점으로 감소하였으며(p<0.001), 마이봄선기능장애정도 또한 치료 전 21.60 ± 6.95점에서 18.02 ± 6.68점으로 호전 정도가 유의미하였다(p=0.001). OSDI는 치료 전 38.83 ± 17.13점에서 치료 1달 후 18.67 ± 15.01점으로 유의미하게 감소하였다(p<0.001). 결론: BlephExTM를 사용 시 MGD에 따른 환자의 증상 호전뿐만 아니라 눈꺼풀 경계 이상을 비롯한 마이봄선기능장애정도, 눈물막파괴정도가 유의미하게 호전되었고, 이는 스테로이드 안약을 사용시 호전 정도가 명확하였다. 이를 통해 MGD 환자들에게 BlephExTM를 사용하는 것을 치료의 한 가지 방안으로 제시하는 바이다.

2P-245 Langmuir-Blodgett Trough를 이용한 meibum 특성에 관한 연구

김세희,이승재,이태규,지용우,전익현,서경률 한국공업화학회 2017 한국공업화학회 연구논문 초록집 Vol.2017 No.0

Causes of Punctal Plug Loss in Sjögren’s Syndrome

서경률,김나은,안현민,전익현,김태임 연세대학교의과대학 2023 Yonsei medical journal Vol.64 No.8

Purpose: To evaluate the long-term maintenance rate and associated factors of silicone punctal plugs in patients with Sjögren’s syndrome (SS). Materials and Methods: We retrospectively reviewed the medical records of 163 patients with SS who underwent silicone punctal plug insertion between December 2013 and July 2021 at Severance Hospital. The status of punctal plug insertions was classified into the following three categories by the clinician: maintenance, spontaneous loss, and intended removal. Cox proportional haz ards model was used to evaluate the risk factors for spontaneous loss. Results: The mean maintenance period was 12.8±15.3 (median 7.07) months. The rate of spontaneous loss was 58%, and the rate of punctal plug removal by the clinician was 14%. The number of prior plug insertions was a risk factor for spontaneous loss [hazard ratio (HR) 1.055, p=0.035]. The upper eyelid punctum was at a higher risk than the lower one (p=0.042). Small-sized plugs showed a significantly higher risk for spontaneous loss than large-sized ones (HR 1.287, p=0.035). Flow-controller type plugs were more vul nerable to spontaneous loss than complete occluders [Micro FlowTM vs. EagleFlex® (HR 2.707, p=0.008) and Micro FlowTM vs. Ul traplugTM (HR 3.402, p=0.005)]. The most common reason for removal was tear overflow (5.6%). Conclusion: In repeated insertion, characteristics of the punctal plug, including the type and size, and location of plug insertion, influenced the spontaneous loss of plugs. The management of punctal plugs, including insertion, maintenance, and removal, re quires personalized strategies for versatile situations.

제2형 과립각막이상증 이형접합자에서 다초점인공수정체 삽입 후의 시기능 고찰 1예

서지형,김태환,최진석,전익현,조상일,김응권 대한안과학회 2023 대한안과학회지 Vol.64 No.6

Purpose: A patient with heterozygous granular corneal dystrophy type 2 (GCD2) underwent phacoemulsification with multifocal intraocular lens insertion, and complained of visual discomfort. We investigated the cause of the discomfort and visual function in this case. Case summary: A 59-year-old woman with granular opacity had slit lamp photographs taken 5 years earlier. Two years later, she underwent phacoemulsification with multifocal intraocular lens (Trifocal AT Lisa tri toric 839MP ® , Carl Zeiss Meditec AG, Inc., Jena, Germany) insertion in both eyes at a local clinic. She felt very uncomfortable after the surgery, but the granular and lattice opacities due to GCD2 of her corneas remained stationary for 5 years. Her visual acuity decreased from preoperatively (preoperative: right 0.5, left 0.6; last visit: right 0.3, left 0.4). Her contrast sensitivity was also decreased and the total higher order aberration was increased (right 1.590 μm, left 1.194 μm), compared to normal range. Conclusions: Multifocal intraocular lens insertion in cataract surgery can lead to severe declines in contrast sensitivity and visual acuity and increased higher-order aberration in a GCD2 patient. It may not be advisable to use multifocal intraocular lenses in a GCD2 patient. 목적: 다초점인공수정체를 삽입한 제2형 과립각막이상증(granular corneal dystrophy type 2, GCD2) 환자가 백내장수술 후 심한 불편감을 호소하여, 그 원인을 시기능적인 면에서 조사하였다. 증례요약: GCD2 각막혼탁을 지닌 59세 여자 환자로 5년 전 세극등현미경으로 각막을 촬영하고, 3년 전 양안 다초점인공수정체 삽입백내장수술(AT Lisa tri toric 839MP®, Carl Zeiss Meditec AG, Inc., Jena, Germany)을 시행받았으나, 수술 후 시력저하를 호소하며본원에 내원하였다. 세극등 사진 비교 시 5년 전에 비하여 각막혼탁의 정도는 변화가 거의 없었다. 하지만 백내장수술 직전 교정시력(우안 0.5, 좌안 0.6)에 비해 수술 후 교정시력(우안 0.3, 좌안 0.4)이 저하되었으며, 대비감도가 저하되었고 총 고위수차는 증가(우안1.590 μm, 좌안 1.194 μm)되어 있었다. 결론: 각막혼탁이 심한 GCD2 환자에서 다초점인공수정체를 삽입한 후, 대비감도의 저하와 시력 감소, 고위수차의 증가가 관찰되었다. 각막혼탁이 심한 GCD2에서 다초점인공수정체 사용은 지양되어야 할 것으로 판단된다.