갑상샘눈병증에서 안와감압술 전후 외안근 부피 변화의 영상분석: Nunery 분류법 제1형과 2형 비교

황규연,조원경,백지선,양석우,Kyu Yeon Hwang,Won Kyung Cho,Ji Sun Paik,Suk Woo Yang 대한안과학회 2013 대한안과학회지 Vol.54 No.1

Purpose: To evaluate the radiographic volume change in extraocular muscles (EOM) following orbital wall decompression for Nunery type 1 and type 2 thyroid-associated orbitopathy (TAO). Methods: Medical records of 31 orbits in 20 patients undergoing postoperative orbital CT after orbital decompression for TAO were retrospectively reviewed. The patients were divided according to Nunery classifications. A type 1 classification was assigned to patients who had no diplopia and essentially normal versions. A type 2 classification was assigned to patients with restrictive motility loss and diplopia within 20 degrees of the primary position. EOM volumes were determined by the summation of each EOM’s cross-sectional areas in the coronal plane of the CT scans and multiplying the sum by the slice thickness. Main outcome measure was a comparison of EOM volume changes between types 1 and 2 TAO and a relationship between EOM volume and change in proptosis. Results: In type 2 TAO, a significant increase in the volume of the medial rectus muscle, lateral rectus, and total EOM was detected postoperatively (p = 0.044, 0.022, 0.049), whereas no significant changes were found in the EOM’s volume changes in type 1 TAO. The reduction of proptosis after orbital decompression in type 1 TAO was significantly greater than in type 2 TAO (p = 0.025). A significant positive association was observed between the preoperative EOM volumes and the reduction of proptosis following orbital wall decompression (r = 0.505). Conclusions: The postoperative EOM volumes following orbital wall decompression was significantly increased in Nunery type 2 patients who had restrictive myopathy.

백내장 수술 후 발생한 독성 전방 증후군

황규연,양지욱,이영춘,김수영,Kyu Yeon Hwang,Ji Wook Yang,Young Chun Lee,Su Young Kim 대한안과학회 2011 대한안과학회지 Vol.52 No.6

Purpose: To report clinical and laboratory findings of toxic anterior segment syndrome (TASS) in seven patients following cataract surgery with intraocular lens (IOL) implantation. Methods: The medical records of seven patients who underwent cataract surgery associated with postoperative decreased visual acuity, ocular pain, anterior chamber inflammation and corneal edema between Feb 2007 and Nov 2009 were retrospectively reviewed. Results: All patients were over 60 years of age, four patients had diabetes and four patients had cardiovascular disease. Five patients had received hydrophilic IOL, and six patients underwent surgery later in order. All seven patients presented with increased anterior segment inflammation, acute decreased visual acuity, and severe corneal edema an average of 10.4 days (range 1 to 15 days) after surgery. Treatment of the seven patients included intensive topical and oral steroids, and improvement was noted in all patients. Conclusions: The incidence of TASS after cataract surgery was 0.8%, and was significantly higher in cases of hydrophilic IOL insertion (5 of 284 cases, 1.76%) compared to cases of hydrophobic IOL insertion (2 of 581 cases, 0.34%) (p = 0.04). Five of the seven cases presented with TASS at postoperative day 14. Inflammation improved in all patients with steroid treatment. J Korean Ophthalmol Soc 2011;52(6):690-695

외사시 환자에서 사시각에 따른 단안 혹은 양안 외직근 후전술 후 사시각 변화와 편차의 비교

황규연,이세엽,이영춘,Kyu Yeon Hwang,Se Yup Lee,Young Chun Lee 대한안과학회 2011 대한안과학회지 Vol.52 No.1

Purpose: To compare the changes in strabismus angle and deviation between two groups: a bilateral lateral rectus recession (Group 1) and a unilateral lateral rectus recession in exotropia (Group 2). Methods: A retrospective survey was conducted on 198 patients who had received exotropia surgery in our ophthalmology clinic from September 2003 to April 2007. A total of 116 patients were in Group 1, and 82 patients were in Group 2. Unilateral lateral rectus recession was performed on patients under 25 PD, and bilateral lateral rectus recession was performed on patients above 25 PD. A case of less than 4 PD esodeviation and less than 10 PD exodeviaton was defined as a success and any other case as a failure at the 1-year follow-up visit. Results: The average deviations of the first postoperative month and the first postoperative year were -1.96 D ± 4.75, 2.5 D ± 7.82 for Group 1 and 0.77 D ± 2.87, 5.94 D ± 3.38 for Group 2. Revealing statistical significance between the 2 Groups: Group 1 had 30 failure cases (25.9%) and their 1 postoperative year average deviation was 5.42 D ± 13.97, while Group 2 showed 24 failure cases (29.3%) and their 1-postoperative-year average deviation was 13.0-79 ± 3.04. Group 1 had less strabismus angle and a greater standard deviation than Group 2, as Group 1 had more overcorrection. Among the 30 failure cases of Group 1, 9 were overcorrected and 21 were undercorrected, but all 24 failure cases in Group 2 were undercorrected. Conclusions: The strabismus angle after lateral rectus recession showed a wider variation and a larger difference in bilateral lateral rectus recession than in the unilateral lateral rectus recession. J Korean Ophthalmol Soc 2011;52(1):60-66

음성/잡음 차등 주파수차감법에 의한 잡음처리 및 기존 주파수차감법과의 성능 비교

황규연(Hwang Kyu-Yeon),이경준(Lee Kyung-Jun),정제창(Jeong Je-Chang) 한국방송·미디어공학회 2016 한국방송공학회 학술발표대회 논문집 Vol.2016 No.11

본 논문에서는 기존에 쓰이던 주파수차감법과 다른 새로운 방법을 제안한다. 본 논문에서 다루는 방법은, 특정한 주파수의 대역에서 음성과 잡음의 우세도를 결정하고, 인간의 청각기와 관련된 매스킹 성질을 기반으로 하여 주파수 차감법을 이용해 제거한다. 이에 대하여 다양한 성능 평가를 하였고, 기존의 일반적인 주파수차감법과 비교하여 보다 효과적으로 잡음처리를 할 수 있음을 알 수 있다.

안구 길이와 유리체절제술이 SRK/T 공식의 굴절 오차에 미치는 영향

이민규,황규연,김만수,Min Kyu Lee,Kyu Yeon Hwang,Man Soo Kim 대한안과학회 2013 대한안과학회지 Vol.54 No.2

Purpose: To investigate the error tendency between preoperative target diopter and postoperative manifest refraction in cataract surgery cases and the effect of axial length and vitrectomy on refractive error (RE). Methods: We retrospectively studied 90 eyes of 90 patients who underwent cataract surgery. The power of intraocular lens (IOL) was calculated by SRK/T formula. Patients were devided into four groups based on axial length (AXL) and the past history of vitrectomy. Results: The mean of RE showed no significant difference between groups. But an increasing AXL was associated with increased myopic shift with normal range AXL (≤24.4 mm) (r = -0.502, p = 0.005) and increased hyperopic shift with long AXL (>24.4 mm) (r = 0.718, p < 0.001). In vitrectomized eyes, it showed no significant refractive shift with both normal range and long AXL. Conclusions: When determining IOL power using SRK/T formula in nonvitrectomized eyes, postoperative refractive shift based on axial length should be considered.

수입 각막에서 보존 기간 동안의 내피세포 감소율이 수술 후 내피세포 생존에 미치는 영향

이국,황규연,김만수.Kook Lee. MD. Kyu Yeon Hwang. MD. Man Soo Kim. MD 대한안과학회 2013 대한안과학회지 Vol.54 No.6

Purpose: To investigate the influence of preoperative endothelial cell loss on the outcome of keratoplasty for keratoconus in imported donor corneas. Methods: Eighteen imported corneas used in keratoplasty for keratoconus patients were evaluated. Corneal endothelial cell density at the moment of preservation was obtained from the medical records and was measured immediately before the keratoplasty. Correlation of the endothelial cell loss count before and after keratoplasty was analyzed and postoperative endothelial cell loss count according to the range of preoperative endothelial cell loss was evaluated. Results: Mean endothelial cell loss before and after keratoplasty was 258.94 ± 128.58 cells/mm2 and 355.44 ± 371.83 cells/mm2, respectively. There was a positive correlation between preoperative and postoperative endothelial cell loss count (r = 0.431, p = 0.074). The results showed statistically significant higher endothelial cell loss count after keratoplasty in the range above 250 cells/mm2 rather than below 250 cells/mm2 of preoperative endothelial cell loss count (p = 0.033). Conclusions: The preoperative decrease in endothelial cell density affected the endothelial cell loss after keratoplasty for keratoconus in imported donor corneas.

공여편 삽입 방법에 따른 데스메막박리 각막내피층판 이식술의 임상결과 비교

백지원,황규연,주천기,Ji Won Baek,Kyu Yeon Hwang,Choun-Ki Joo 대한안과학회 2013 대한안과학회지 Vol.54 No.11

Purpose: To compare clinical outcomes of Descemet’s stripping automated endothelial keratoplasty (DSAEK) between different graft insertion methods Methods: The clinical records of 32 eyes of 30 DSAEK patients were retrospectively analyzed. Patients were divided into 2 groups according to graft insertion method. Group A: Taco-folding, group B: Tan-endoglide. The best corrected visual acuities (BCVA), intraocular pressures, astigmatism, endothelial cell count, central corneal thickness and complications were evaluated pre and post-operatively. Results: The average follow-up period was 19 months (range 1-67). Postoperative log MAR visual acuity had significantly improved both from 1.63 (log MAR) to 0.69 and 0.53 at 12 months in each group (p = 0.035, p = 0.000). Mean endothelial cell survival of each group at 1 month postoperative were 75.8% (range 62.7-88.6) and 87.7% (range 70.2-97.9), respectively (p = 0.012). The differences of BCVA improvement and endothelial cell survival between the groups at 12 months were not significant (p = 0.393, p = 0.544). Conclusions: Both methods showed fast visual recovery. Using Tan-endoglide insertion resulted less endothelial cell loss at early post-operative period and showed less post-operative complication and graft failure. J Korean Ophthalmol Soc 2013;54(11):1655-1662

짧은 안축장에서 백내장수술 후 굴절오차 분석과 각막굴절력 및 전방깊이에 따른 정확성 분석

신정아,황규연,김만수,Jeong Ah Shin,Kyu Yeon Hwang,Man Soo Kim 대한안과학회 2013 대한안과학회지 Vol.54 No.1

Purpose: To evaluate the accuracy of the chosen formula in short eyes and the effect of the anterior chamber depth (ACD) and corneal refractive power on the accuracy. Methods: A total of 251 eyes out of 185 patients (axial length below 22.0 mm) who underwent cataract surgery in our hospital were retrospectively studied. Introcular lens (IOL) power was calculated with the Hoffer Q, SRK II, SRK-T and Holladay 1 formulas and refractive outcome was measured. Patients were divided into 2 groups based on ACD. The accuracy of the 4 formulas was compared and the errors according to the ACD were also evaluated. Results: In eyes with short axial lengths, all formulas showed a tendency for hyperopic shifts. The Hoffer Q formula showed significantly high predictive accuracy. This tendency for hyperopic shifts was similar in the eyes with extremely short axial length, but a large refractive error deviation was observed. The 2 groups based on ACD showed no significant difference in the refractive error, but the group with deep ACD had a tendency for hyperopic shifts. The difference of the calculated IOL power between the 4 formulas was more pronounced in eyes with lower corneal refractive power. Conclusions: In eyes with short axial lengths, preoperative ACD and corneal refractive power had an influence on the accuracies of predicted IOL power. Therefore, these factors should be considered in IOL power determination.

전층각막이식술을 받은 반점각막이상증 환자의 장기 임상성적

이지명,황규연,황호식,김만수,Ji Myung Lee,Kyu Yeon Hwang,Ho Sik Hwang,MS,Man Soo Kim 대한안과학회 2012 대한안과학회지 Vol.53 No.10

Purpose: To report the long term clinical results of penetrating keratoplasty as a treatment for corneal macular dystrophy. Methods: Retrospective review of the medical record of 46 eyes (31 indivisuals) who underwent primary PK for corneal macular dystrophy at the Seoul St. Mary’s Hospital between November, 1986 and December, 2011. Data extracted preoperative and postoperative best-corrected visual acuity (BCVA), postoperative complications (including graft rejection episodes, and recurrent dystrophy), change of endothelial cell density at 1, 6, 12, 24, 36 months and yearly thereafter. Results: After a mean follow-up period of 91.59 ± 3.2 months, the mean BCVA was significantly improved after penetrating keratoplasty. Endothelial cell loss rate was marked during the 1st year after penetrating keratoplasty. Graft survival was 40 graft (89.7%) at 8yrs. There was a statistically significant increased likelihood of graft failure if the patient was older than 40 years at the time of surgery (p = 0.03). Glaucoma as postoperative complication was 17.4%. Clinically significant recurrence was 2%. Conclusions: Penetrating keratoplasty is associated with a good visual outcome and prognosis for graft survival of long-term efficacy with a low complication rate in eyes with macular corneal dystrophy. J Korean Ophthalmol Soc 2012;53(10):1425-1431

개방형고리를 이용한 수정체전낭 원형절개술의 유용성

김수아,이용은,황규연,주천기,Su Ah Kim,MD,Yong Eun Lee,MD,Kyu Yeon Hwang,MD,Choun-Ki Joo,MD,PhD 대한안과학회 2013 대한안과학회지 Vol.54 No.10

Purpose: To compare the size, circularity and repeatability between the conventional manual technique and the open-ring guided continuous curvilinear capsulorrhexis (CCC) technique in cataract surgery. Methods: The present study comprised 120 eyes divided into two equal groups. In the first group (group A), CCC was performed using a 5.3-mm open ring-shaped caliper and in the second group (group B), CCC was performed using the conventional manual technique. Photographs were taken after each surgical step (CCC, phacoemulsification, Intraocular lens insertion and corneal stromal hydration). The diameter, area and circularity of the anterior capsule were compared between the two groups. Results: The anterior capsule diameter was 5.32 ± 0.26 mm for group A (coefficient of variation 0.049) and 5.14 ± 0.64 mm for group B (coefficient of variation 0.125); the area was 22.9 ± 0.71 mm2 for group A (coefficient of variation 0.031) and 21.40 ± 1.37 mm2 for group B (coefficient of variation 0.064). Circularity was 0.93 ± 0.24 for group A (coefficient of variation 0.258) and 0.86 ± 0.78 for group B (coefficient of variation 0.907). Conclusions: The open ring-guided CCC technique resulted in an increase of diameter and capsulorrhexis area. This method showed superior circularity and repeatability compared to conventional manual technique and can be useful in cataract surgery.