대한안과학회지 2015 년제 56 권제 11 호 J Korean Ophthalmol Soc 2015;56(11):1712-1719 ISSN 0378-6471 (Print) ISSN 2092-9374 (Online) http://dx.doi.org/10.3341/jkos.2015.56.11.1712 Original Article 경한난시를보이는환자의백내장수술후각막후면및전체난시의변화 The Change in Corneal Astigmatism after Cataract Surgery in Patients with Small Amount of Astigmatism 양희정 박율리 김현승 Hee Jung Yang, MD, Yu Li Park, MD, Hyun Seung Kim, MD, PhD 가톨릭대학교의과대학여의도성모병원안과및시과학교실 Department of Ophthalmology and Visual Science, Yeouido St. Mary s Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea Purpose: To analyze the change in posterior corneal astigmatism and total corneal astigmatism in patients with anterior corneal astigmatism less than 1.0 diopter (D). Methods: In the present study we evaluated 52 eyes with anterior corneal astigmatism less than 1.0 D. Patients were divided into 2 groups according to steep axis: Group 1 included 33 eyes with within-the-rule (WTR) astigmatism and Group 2 included 19 eyes with against-the-rule (ATR) astigmatism. Anterior, posterior and total corneal astigmatism were measured using Scheimpflug imaging (Pentacam ). Results: In Group 1, preoperative anterior astigmatism, posterior astigmatism and total astigmatism were 0.55 ± 0.44 D, 0.31 ± 0.14 D and 0.30 ± 0.72 D, respectively. At postoperative 2 months, anterior astigmatism, posterior astigmatism and total astigmatism were 0.51 ± 0.67 D, 0.31 ± 0.15 D and 0.35 ± 0.81 D, respectively. There was no statistically significant difference between preoperative and postoperative anterior, posterior and total corneal astigmatism in Group 1. In Group 2, preoperative anterior astigmatism, posterior astigmatism and total astigmatism were -0.48 ± 0.46 D, 0.26 ± 0.09 D and -0.51 ± 0.65 D, respectively. At postoperative 2 months, anterior astigmatism, posterior astigmatism and total astigmatism were -0.17 ± 0.68 D, 0.25 ± 0.13 D and -0.30 ± 0.55 D, respectively. There was no statistically significant difference between preoperative and postoperative anterior, posterior and total corneal astigmatism in the 2 groups. There was no statistical correlation between preoperative posterior corneal astigmatism and postoperative 2 months total corneal astigmatism. After vector analysis, surgically induced astigmatism (SIA) of the anterior and total astigmatism in Group 1 were 0.03 D @ 30 and 0.07 D @ 74, respectively, and in Group 2 were 0.27 D @ 100 and 0.36 D @ 86, respectively. Conclusions: In patients with preoperative total corneal astigmatism less than 1.0 D, posterior corneal astigmatism had a small effect on postoperative total corneal astigmatism. J Korean Ophthalmol Soc 2015;56(11):1712-1719 Key Words: Pentacam, Posterior corneal astigmatism, Total corneal astigmatism Received: 2015. 5. 29. Revised: 2015. 7. 29. Accepted: 2015. 9. 25. Address reprint requests to Hyun Seung Kim, MD, PhD Department of Ophthalmology, Yeouido St. Mary s Hospital, #10, 63-ro, Yeongdeungpo-gu, Seoul 07345, Korea Tel: 82-2-3779-1243, Fax: 82-2-761-6869 E-mail: sara514@catholic.ac.kr 최근백내장수술의수요가증가하고수술기법의발전이이루어지며백내장수술은단순히시력개선을위한목적뿐아니라노시안의교정및굴절교정의목적으로도시행되고있다. 수술결과에대한환자의기대가높아지며난시를교정하기위한기법으로토릭인공수정체의사용및각막윤부절제술, 펨토초레이저를이용한궁상절개등의 c2015 The Korean Ophthalmological Society This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. 1712
- 양희정외 : 경한각막난시의술후후면난시변화 - 다양한방법들이수술전난시의정도에따라이용되고있으며정확한각막난시를측정하는것에대한중요성이강조되고있다. 1 각막전면난시만을고려하여백내장수술이시행되었을때, 특히토릭인공수정체를이용하여난시를교정할경우수술전예측했던것과다른결과가초래되는경우가있는데 2 각막후면난시를측정할수있는기기들이개발되면서각막전면난시만으로전체각막난시를예측하였을경우의예측오차에대한연구들이발표되었고 3-5 또한각막후면난시의정도와술후각막후면난시에서의수술후유발난시량의관련성에대한연구들이발표되며특히토릭인공수정체를이용한난시교정시각막후면난시의중요성이대두되고있다. 6 Ferrer-Blasco et al 7 의연구에서백내장이있는환자의 66% 에서 0.25-1.25D 사이의각막난시를가지고있었으며, Hoffer 8 의연구에서환자의 76.8% 에서 0.25-1.50D 사이의각막난시를가진다는연구결과를토대로하여본연구에서는 Pentacam (Oculus, Wetzlar, Germany) 을이용하여측정한전면각막난시, 1.0D 미만의경한난시를가지고있는환자를대상으로하여술후각막후면난시의변화에대하여알아보고자하였다. 또한각막후면난시의경축이 86.6% 의환자에서수직으로존재하며나이에따른경축의변화가적다는연구결과를바탕으로하여 5 환자군을직난시군과도난시군으로나누어각각의군에서의각막전면난시와후면난시사이의상관성및각막후면난시가술후전체난시에미치는영향에대하여알아보고자하였다. 대상과방법 2014년 9월부터 2014년 12월사이에백내장수술을받은환자중술전 1.0D 미만의전면각막난시를가진 52명 (52안) 을대상으로하였다. 수술전부정난시를유발할수있는각막질환이나안구내염증, 녹내장, 약시, 시신경병증그리고망막질환이있거나, Lens Opacities Classification System (LOCS) III 분류에의해핵성경화 (Nuclear sclerosis) 정도가 5 이상이거나술전전층각막이식술이나굴절교정수술, 녹내장수술, 유리체망막수술등을받은경우, 술중후낭파열, 인공수정체이탈, 중심이탈및기울임이발생한경우는연구대상에서제외하였다. 술전및술후각막난시는전면난시, 후면난시, 전체난시로나누어서 Pentacam (Oculus, Wetzlar, Germany) 을이용하여술전, 술후 1일, 술후 1개월, 술후 2개월째측정하였다. 술전안축장길이의측정에는 IOL master 를이용하였으며술전전방의깊이는 Pentacam 의 3D anterior chamber depth analysis를이용하여측정하였으며각막내피 세포는 Keeler Konan specular microscope를이용하여측정하였다. Pentacam 각막지형도의 simk 값을기준으로직난시는각막곡률의가파른축이 60-120 사이에있는군으로정의하였으며도난시는각막곡률의가파른축이 0-30, 150-180 사이에있는군으로정의하여술전각막전면난시가 1.0D 미만인환자를직난시를보이는 1군 (33안) 과도난시를보이는 2군 (19안) 으로나누었다. 두군모두투명각막절개창은각막지형도의 simk 값을기준으로하여각막곡률이가파른축에형성하였다. 모든백내장수술은 0.5% paracaine hydrochloride (Alcaine, Alcon, Fort Worth, TX, USA) 를이용하여점안마취후 Infiniti Vision System (Alcon) 을이용하여한명의술자에의하여시행되었다. 2.8 mm 투명각막절개를시행후 5.0-5.5 mm의원형전낭절개술을시행하고평형염액 (Balanced salt solution, BSS, Alcon, Fort Worth, TX, USA) 을사용하여수력분리술과수력분층술을시행한후핵의초음파유화술을시행하였다. 이후관류흡입기 (irrigation/aspirationdevice) 로남아있는수정체피질을제거하였으며점탄물질 (Hyal 2000, LG Life Science, Seoul, Korea) 을전방에주입한후인공수정체를낭내에삽입하였다. 이후낭내점탄물질을관류흡입기를이용하여제거하였으며술후각막봉합이난시에미칠수있는영향을방지하기위하여각막봉합은시행하지않았다. 난시의절대값과방향을함께고려한난시변화분석을위해직난시의경우에는난시의절대값에 +1을, 도난시의경우에는 -1을곱하여직난시또는도난시를고려하여비교하였다. 9 수술로인한난시변화 (Surgically induced astigmatism) 는 SIA calculator version 2.1 소프트웨어 (http://www.insighteyeclinic. in/sia_calculator.php) 와이를도식화하기위하여 AstigPLOT 프로그램을이용하였다. 또한난시의절대값을이용하여술전각막전면난시와술전각막후면난시사이의상관성및술전각막후면난시와술후각막전체난시사이의상관성을직난시군과도난시군에서각각분석하였다. 통계분석은 SPSS 19.0 (SPSS Inc., Chicago, IL, USA) 을이용하였으며 p값이 0.05 미만인경우통계학적인의의가있는것으로판단하였다. 두군의수술전후난시변화의비교에는 paired-t-test와 Wilcoxon 부호순위검정이이용되었으며두군간수술후유발된난시량의비교에는 independent-t test가이용되었다. 술전전면난시와술전후면난시의상관성및술전후면난시와술후후면난시의상관성분석에는 spearman 상관검사가이용되었다. 결과 백내장수술을시행한 52 안중술전직난시를보인 1 군 1713
- 대한안과학회지 2015 년제 56 권제 11 호 - Table 1. Preoperative clinical characteristics of each group Group 1 (n = 33) Group 2 (n = 19) p-value Total group Sex (female:male) 24:9 13:6 0.692 37:15 Age (years) 65.7 ± 12.4 69.1 ± 7.5 0.290 66.91 ± 10.93 Laterality (right eye:left eye) 14:19 7:12 0.606 * 21:31 BCVA (log MAR) 0.31 ± 0.23 0.31 ± 0.57 1.000 0.31 ± 0.38 IOP (mm Hg) 13.3 ± 2.8 14.4 ± 2.8 0.153 13.6 ± 3.1 Axial length (mm) 24.27 ± 2.06 23.70 ± 1.85 0.324 24.06 ± 1.99 ACD (mm) 2.63 ± 0.60 2.59 ± 0.43 0.822 2.62 ± 0.54 Central corneal thickness (μm) 546 ± 41 545 ± 29 0.923 545 ± 37 Corneal endothelium cell density (cells/mm 2 ) 2,706 ± 485 2,880 ± 343 0.174 2,768 ± 444 Corneal astigmatism (algebraic value, D) Anterior 0.55 ± 0.44-0.48 ± 0.46 0.000 0.18 ± 0.67 Posterior 0.31 ± 0.14 0.26 ± 0.09 0.124 0.29 ± 0.13 Total 0.30 ± 0.72-0.51 ± 0.65 0.000 0.04 ± 0.79 Values are presented as mean ± SD unless otherwise indicated. Group 1 is within-the-rule group and Group 2 is against-the-rule group. BCVA = best corrected visual acuity; IOP = intraocular pressure; ACD = anterior chamber depth. * Statistically significant differences (p-value < 0.05) in Pearson's chi-square test; Statistically significant differences (p-value < 0.05) in independent t-test; Statistically significant differences (p-value < 0.05) in Mann Whitney U-test. Table 2. Preoperative and postoperative corneal astigmatism (algebraic value) Pre-op Post-op 1 day Post-op 1 month Post-op 2 months Group 1 Anterior (D) 0.55 ± 0.44 0.23 ± 0.81 0.39 ± 0.82 0.51 ± 0.67 Posterior (D) 0.31 ± 0.14 0.41 ± 0.21 0.29 ± 0.17 0.31 ± 0.15 Total (D) 0.30 ± 0.72 0.18 ± 1.15 0.17 ± 0.96 0.35 ± 0.81 Group 2 Anterior (D) -0.48 ± 0.46-0.10 ± 0.70-0.13 ± 0.69-0.17 ± 0.68 Posterior (D) 0.26 ± 0.09 0.33 ± 0.19 0.21 ± 0.11 0.25 ± 0.13 Total (D) -0.51 ± 0.65-0.06 ± 0.80-0.51 ± 0.47-0.30 ± 0.55 Total group Anterior (D) 0.18 ± 0.67 0.11 ± 0.77 0.20 ± 0.80 0.26 ± 0.75 Posterior (D) 0.29 ± 0.13 0.38 ± 0.21 0.26 ± 0.16 0.29 ± 0.14 Total (D) -0.01 ± 0.80 0.09 ± 1.03-0.08 ± 0.87 0.11 ± 0.78 Values are presented as mean ± SD unless otherwise indicated. Group 1 is within-the-rule group and group 2 is against-the-rule group. Pre-op = preoperative; Post-op = postoperative. Table 3. Comparison of preoperative and postoperative 2 month corneal astigmatism (algebraic value) Pre-op Post-op 2 months p-value Group 1 Anterior (D) 0.55 ± 0.44 0.51 ± 0.67 0.706 * Posterior (D) 0.31 ± 0.14 0.31 ± 0.15 1.000 Total (D) 0.30 ± 0.72 0.35 ± 0.81 0.701 * Group 2 Anterior (D) -0.48 ± 0.46-0.17 ± 0.68 0.036 Posterior (D) 0.26 ± 0.09 0.25 ± 0.13 0.867 * Total (D) -0.51 ± 0.65-0.30 ± 0.55 0.216 * Total group Anterior (D) 0.18 ± 0.67 0.26 ± 0.75 0.335 * Posterior (D) 0.29 ± 0.13 0.29 ± 0.14 0.926 * Total (D) -0.01 ± 0.80 0.11 ± 0.78 0.293 * Values are presented as mean ± SD unless otherwise indicated. Group 1 is within-the-rule group and Group 2 is against-the-rule group. Pre-op = preoperative; Post-op = postoperative. * Statistically significant differences (p-value < 0.05) in paired t-test; Statistically significant differences (p-value < 0.05) in Wilcoxon signed-rank test. 이 33안이었으며술전도난시를보인 2군은 19안이었다. 환자연령, 성별, 술전최대교정시력, 안압, 안축장길이, 전방깊이, 중심각막두께, 각막내피세포는 1군과 2군사이에유의한차이가없었다. 1군에서술전전면, 후면, 전체난시는각각 0.55 ± 0.44D, 0.31 ± 0.14D, 0.30 ± 0.72D였으며 2군에서술전전면난시는 -0.48 ± 0.46D, 0.26 ± 0.09D, -0.51 ± 0.65D로술전각막전면및전체난시에통계학적으로유의한차이 1714
- 양희정외 : 경한각막난시의술후후면난시변화 - A-1 SIA-A A-2 SIA-T B-1 SIA-A B-2 SIA-T Figure 1. Double-angle plots of surgically induced astigmatism (SIA) of anterior corneal astigmatism (SIA-A) and total corneal astigmatism (SIA-T) in (A) WTR group and (B) ATR group. WTR = within-the-rule; ATR = against-the-rule. 가있었으며후면난시는두군사이에유의한차이가없었다 (p=0.00, 0.12, 0.00) (Table 1). 술후 2개월째 1군에서술후전면, 후면, 전체난시는각각 0.51 ± 0.67D, 0.31 ± 0.15D, 0.35 ± 0.81D였으며, 2군에서술후전면, 후면, 전체난시는각각 -0.17 ± 0.68D, 0.25 ± 0.13D, -0.30 ± 0.55D로술전과술후 2개월째의각막전면, 후면및전체난시를비교하였을때제1군에서각막전면, 후면, 전체난시에서모두술전과술후에유의한차이가없었으며 (p=0.706, 1.000, 0.701), 2군에서는각막후면및전체난시에서술전과술후에유의한차이가없었고전면난시의경우통계학적으로유의하게난시가감소하였다 (p=0.036, 0.867, 0.216). 전체 52안에서는술전과술후각막전면, 후면및전체난시사이에유의한차이가없었다 (p=0.335, 0.926, 0.293) (Table 2, 3). 술후 2개월에시행한각막지형도검사를바탕으로하여 SIA calculator를이용하여계산한후 vector analysis를시행하였을때수술후난시유발량은 1군의경우전면난시의 SIA는 0.03D @ 30, 전체난시의 SIA가 0.07D @ 74 였으며 2군의경우전면난시의 SIA는 0.27D @ 100, 전체난시의 SIA가 0.36D @ 86 로측정되었다. Fig. 1은직난시군과도난시군, 전체군에서의전면난시와전체난시의 SIA를 AstigPLOT을이용하여도식화한것이다. 술전전면난시와후면난시의상관분석을시행한결과전체군에서는술전전면난시와후면난시사이에상관관계가없었으며 (r=0.015, p=0.92), 직난시군에서는술전전면난시와후면난시사이에통계학적으로유의한양의상관관계를보였다 (r=0.379, p=0.04). 직난시군및도난시군에서각각수술전각막후면난시와술후 2개월의각막전체난 1715
- 대한안과학회지 2015 년제 56 권제 11 호 - A R 2 linear = 0.008, p = 0.920 R 2 linear = 0.142, p = 0.04 B Preoperative anterior astigmatism (D) Preoperative anterior astigmatism (D) C R 2 linear = 0.179, p = 0.014 Preoperative anterior astigmatism (D) Figure 2. Correlation analysis between preoperative anterior astigmatism and posterior astigmatism in (A) total group, (B) WTR group and (C) ATR group. WTR = within-the-rule; ATR = against-the-rule. 시의상관분석을시행한결과직난시군과도난시군에서모두술전각막후면난시와술후각막전체난시사이에유의한상관관계를보이지않았다 (r=-0.144, p=0.50; r=0.048, p=0.813) (Fig. 2, 3). 또한전체 52안을수술전후난시축의변화양상에따라나누어분석한결과술전직난시에서도난시로혹은도난시에서직난시로난시의경축이바뀐군의경우총 13안으로술전각막전면난시는 0.23 ± 0.46D, 후면난시는 0.32 ± 0.17D, 전체난시는 -0.22 ± 0.61D였으며술전직난시가 9안, 도난시가 4안이었다. 난시의경축이바뀌지않은총 39안의경우술전각막전면난시는 0.16 ± 0.73D, 후면난시는 0.28 ± 0.11D, 전체난시는 0.06 ± 0.85D였으며술전직난시가 24안, 도난시가 15안이었다. 난시의경축이바뀐 군과그렇지않은군에서술전경축의방향빈도및술전각막전면, 후면및전체난시사이에는통계학적으로유의한차이가없었다 (p=0.51, 0.684, 0.357, 0.195) (Table 4). 고찰 백내장수술을시행할때각막난시를줄여주는다양한방법들이존재하며술자는술전각막난시의양을고려하여수술방법을선택하게된다. 각막후면난시를측정할수있는기법들이발전하며 OrbScan (Bausch and Lomb, Rochester, NY, USA), Pentacam (Oculus, Wetzlar, Germany), Sirius (CostruzioneStrumentiOftalmici, Florence, Italy), Galilei dual Scheimpflug analyzer (Zeimer Group, Port, Switzerland) 와 1716
- 양희정외 : 경한각막난시의술후후면난시변화 - A R 2 linear = 0.042, p = 0.501 R 2 linear = 0.019, p = 0.813 B Preoperative posterior astigmatism (D) Preoperative posterior astigmatism (D) Figure 3. Correlation analysis between preoperative posterior astigmatism and postoperative total astigmatism in (A) WTR group and (B) ATR group. WTR = within-the-rule; ATR = against-the-rule. Table 4. Comparison of preoperative corneal astigmatism between two groups according to changes in the steep axis Changed group Unchanged group p-value No. of eyes 13 39 WTR/ATR 9/4 24/15 0.51 * Corneal Astigmatism (algebraic value) Anterior 0.23 ± 0.46 0.16 ± 0.73 0.684 Posterior 0.32 ± 0.17 0.28 ± 0.11 0.357 Total -0.22 ± 0.61 0.06 ± 0.85 0.195 Values are presented as mean ± SD unless otherwise indicated. WTR = within-the-rule; ATR = against-the-rule. * Statistically significant differences (p-value < 0.05) in Pearson's chi-square test; Statistically significant differences (p-value < 0.05) in independent t-test; Statistically significant differences (p-value < 0.05) in Mann Whitney U-test. 같은다양한기기들이개발되고있으며 3-5 이중본연구에서사용된 Pentacam 은 360도로카메라가회전하는샤임플러그사진기원리를이용하여 2초가량의스캔을통해얻은화상으로각막전면및후면의모양과굴절력, 각막두께, 전방깊이를측정할수있는기기로써펜타캠을이용하여측정한전체각막난시는각막후면에서의난시와각막전면난시에의해유발되는난시의벡터의합을이용하여얻어진다. 10-12 각막후면난시를측정할수있는기기들이개발되며백내장수술을시행함에있어술전난시를교정할때후면난시에대한임상적관심도가증가하였고, 이에대한많은논문들이발표되고있다. 나이에따른각막전 후면난시의경향에대한연구에의하면나이가들수록각막전면난시는직난시에서도난시로바뀌는경향을보이며후면난시의경우나이에의한영향을적게받는다. 5,13,14 또한각막후면 난시는 86.6% 에서수직인경축을가진다고보고된바있으며이것은결국전체각막에대하여 net ATR astigmatism 을유발하게된다. net ATR astigmatism을유발하는후면난시를고려하였을때각막전면난시만을고려하여토릭인공수정체를삽입하게될경우도난시를가진사람은술후부족교정이되며, 직난시를가진사람의경우술후과교정된결과를보이게된다. 2,6,15 다양한기기를이용한각막후면난시의평균값은 0.26-0.78D로보고되고있다. 16-18 각막후면난시를배제하였을때전체각막난시의축과크기가부정확하게측정되며수술후유발난시량역시예측도가떨어진다는연구들이있고술전각막후면난시의크기가커질수록후면에좀더많은수술유발난시량이유도되며이로인하여각막후면난시와각막후면의수술유발난시량이백내장수술후잔여각막난시를예측하고줄이는계획을세우는데에중요한요소가될수있음이강조되 1717
- 대한안과학회지 2015 년제 56 권제 11 호 - 고있다. 6 본연구에서술전후면난시의평균값은 0.29D였으며전면난시의경축에관계없이 52안모두경축이수직으로존재하였다. 술전각막전면난시와후면난시사이의상관성을분석하였을때직난시군에서는양의상관관계가있었다. Nemeth et al 6 이발표한기존의연구결과에의하면직난시군에서는각막전면난시와후면난시는양의상관관계를보였으며도난시군에서는전면난시와후면난시사이에유의한상관관계를보이지않아본연구의결과와일치하였으나, 추후환자군을늘려연구하였을때더욱의미있는결과를얻을수있으리라생각된다. 술전각막후면난시와술후각막전체난시사이의상관관계분석에서직난시군과도난시군에서모두유의한상관관계가없었으며전체환자에서술전각막후면난시는 0.29D, 각막전체난시는 -0.01D였으며술후각막후면난시는 0.29D, 전체난시는 -0.08D로술전과술후후면및전체난시사이에유의한차이를보이지않았다. 직난시군과도난시군으로나누어보았을때직난시군의경우술전각막후면난시는 0.32D, 술후각막후면난시는 0.31D였으며도난시군의경우술전각막후면난시는 0.26D, 술후각막후면난시는 0.25D로직난시군과도난시군에서모두술전과술후각막후면난시사이에유의한차이를보이지않았다. Fig. 1은직난시군과도난시군에서수술 2개월째의전면난시와전체난시의 SIA를 vector analysis하여 double angle plot에도식화한것으로직난시군의경우전면난시의 SIA는 0.03D @ 30, 전체난시의 SIA가 0.07D @ 74 였으며도난시군의경우전면난시의 SIA는 0.27D @ 100, 전체난시의 SIA가 0.36D @ 86 였다. 전면난시만을고려하여 SIA를측정하였을때 SIA 예측에편차가생길수있다는이전의연구들중 Ho et al 4 의연구에서 0.12D, Cheng et al 3 의연구에서 0.14D로전면난시의 SIA와전체난시의 SIA 사이에차이가있던것과비교하였을때, 전면난시가 1D 미만인환자를대상으로한본연구에서는직난시군에서 0.04D, 도난시군에서 0.09D로, 기존의연구들에비하여작은차이를보여경한난시를가진사람에서수술후유발난시량과술후전체난시의예측에후면난시가미치는영향이적다는것을유추할수있다. 한편현재까지의난시교정인공수정체삽입에있어후면난시의영향을고려한연구들에의하면직난시를가진환자의경우후면난시를무시하였을때과교정이되는결과를초래할수있고특히젊은사람의경우나이가들수록도난시로변하는경향을고려하여직난시가약간남아있도록교정해야하므로젊은사람에서난시교정인공수정체를삽입해야할때후면난시를고려하여과교정이되지않도 록주의를기울여야한다고보고되고있다. 5,13,14 최근 0.68D 의경한난시를보이는환자에서토릭인공수정 체를이용하여좋은결과를얻었다는연구가있었는데 19,20 본연구에서전면각막난시 1.0D 미만의환자에서각막후 면난시와술후각막전체난시사이에유의한상관성이없 었으며경미한정도의난시를가진환자에서백내장수술 을시행할때각막후면난시가수술후유발난시량을예측 하는데에미치는영향이적다는결과가나왔다. 이를통해 1.0D 미만의난시를가진환자에서토릭인공수정체삽입 을고려할경우각막후면난시가술후난시에미치는영향 이적다는결론을내릴수있다. 이전의각막후면난시의변화에대한여러연구에서백 내장수술은각막곡률의가파른축에투명각막절개를통하 여이루어졌으며 3,6 본연구에서역시환자를직난시군과도 난시군으로나누어각막곡률의가파른축에절개를가하였 다. Magdum et al 21 의연구에서상측투명각막절개가하측 투명각막절개에비하여수술후유발난시량이더큰결과 를보여주었는데이전의각막후면난시에대한연구중상 측투명각막절개와하측투명각막절개가각각각막후면난 시에미치는영향에대한연구는없었다는점, 각막후면난 시가전체각막난시에서도난시방향에기여한다는점을 고려하였을때 6 절개창의방향에따라후면난시의변화가 기존의연구결과와다르게나타날수있으므로추후직난 시군과도난시군에서각각상측절개와이측절개를시행하 여후면난시의변화를비교하는연구가필요하다. 또한본연구에서난시의경축이바뀌는요인에대한파 악을위하여경축의방향이바뀌는군과그렇지않은군사 이의술전요소에대하여비교를시행하였으나통계학적 으로의미있는요소를발견하지못하였는데이는난시의 경축이바뀐군의빈도가그렇지않은군에비하여그빈도 가적기때문일것으로생각되며추후환자군을늘려서연 구를진행할필요가있다. 결론적으로, 본연구에서는술전 1.0D 미만의경도의난시를가진환자에서는각막후면난시가수술후난시유발량의예측에미치는영향이적음을알수있다. 참고문헌 1) Rubenstein JB, Raciti M. Approaches to corneal astigmatism in cataract surgery. Curr Opin Ophthalmol 2013;24:30-4. 2) Koch DD, Jenkins RB, Weikert MP, et al. Correcting astigmatism with toric intraocular lenses: effect of posterior corneal astigmatism. J Cataract Refract Surg 2013;39:1803-9. 3) Cheng LS, Tsai CY, Tsai RJ, et al. Estimation accuracy of surgically induced astigmatism on the cornea when neglecting the posterior corneal surface measurement. Acta Ophthalmol 2011;89:417-22. 1718
- 양희정외 : 경한각막난시의술후후면난시변화 - 4) Ho JD, Tsai CY, Liou SW. Accuracy of corneal astigmatism estimation by neglecting the posterior corneal surface measurement. Am J Ophthalmol 2009;147:788-95, 795.e1-2. 5) Koch DD, Ali SF, Weikert MP, et al. Contribution of posterior corneal astigmatism to total corneal astigmatism. J Cataract Refract Surg 2012;38:2080-7. 6) Nemeth G, Berta A, Szalai E, et al. Analysis of surgically induced astigmatism on the posterior surface of the cornea. J Refract Surg 2014;30:604-8. 7) Ferrer-Blasco T, Montés-Micó R, Peixoto-de-Matos SC, et al. Prevalence of corneal astigmatism before cataract surgery. J Cataract Refract Surg 2009;35:70-5. 8) Hoffer KJ. Biometry of 7,500 cataractous eyes. Am J Ophthalmol 1980;90:360-8. 9) Olsen T, Dam-Johansen M. Evaluating surgically induced astigmatism. J Cataract Refract Surg 1994;20:517-22. 10) Amesbury EC, Miller KM. Correction of astigmatism at the time of cataract surgery. Curr Opin Ophthalmol 2009;20:19-24. 11) Yong Park C, Do JR, Chuck RS. Predicting postoperative astigmatism using Scheimpflug keratometry (Pentacam) and automated keratometry (IOLMaster). Curr Eye Res 2012;37:1091-8. 12) Montalbán R, Piñero DP, Javaloy J, Alió JL. Scheimpflug photography-based clinical characterization of the correlation of the corneal shape between the anterior and posterior corneal surfaces in the normal human eye. J Cataract Refract Surg 2012;38:1925-33. 13) Ueno Y, Hiraoka T, Beheregaray S, et al. Age-related changes in anterior, posterior, and total corneal astigmatism. J Refract Surg 2014;30:192-7. 14) Kim CS, Ryu JW, Kim HS, Lee YC. Distribution and change of total astigmatism, corneal astigmatism and residual astigmatism with age in patient with emmetropia. J Korean Ophthalmol Soc 2005; 46:485-93. 15) Zhang L, Sy ME, Mai H, et al. Effect of posterior corneal astigmatism on refractive outcomes after toric intraocular lens implantation. J Cataract Refract Surg 2015;41:84-9. 16) Royston JM, Dunne MC, Barnes DA. Measurement of posterior corneal surface toricity. Optom Vis Sci 1990;67:757-63. 17) Royston JM, Dunne MC, Barnes DA. Measurement of the posterior corneal radius using slit lamp and Purkinje image techniques. Ophthalmic Physiol Opt 1990;10:385-8. 18) Dunne MC, Royston JM, Barnes DA. Posterior corneal surface toricity and total corneal astigmatism. Optom Vis Sci 1991;68:708-10. 19) Aujla JS, Vincent SJ, White S, Panchapakesan J. Cataract surgery in eyes with low corneal astigmatism: implantation of the Acrysof IQ toric SN6AT2 intraocular lens. J Ophthalmic Vis Res 2014; 9:324-8. 20) Ernest P, Potvin R. Effects of preoperative corneal astigmatism orientation on results with a low-cylinder-power toric intraocular lens. J Cataract Refract Surg 2011;37:727-32. 21) Magdum RM, Gahlot A, Maheshgauri RD, Patel K. A comparative study of surgically induced astigmatism in superior and temporal scleral incision in manual small incision cataract surgery. Natl J Med Res 2012;2:497-500. = 국문초록 = 경한난시를보이는환자의백내장수술후각막후면및전체난시의변화 목적 : 각막전면난시가 1.0D 미만인환자에서백내장수술후각막후면난시및전체난시의변화를비교분석하였다. 대상과방법 : 각막곡률이가파른축에백내장수술을시행받은 1.0D 미만의각막전면난시를가진환자 52 안을직난시를보이는 33 안 (1 군 ) 과도난시를보이는 19 안 (2 군 ) 으로분류하여 Pentacam 으로측정한각막전면, 후면, 전체난시를비교하였다. 결과 : 직난시군에서술전전면, 후면, 전체난시는 0.55 ± 0.44D, 0.31 ± 0.14D, 0.30 ± 0.72D 였으며술후 2 개월전면, 후면, 전체난시는 0.51 ± 0.67D, 0.31 ± 0.15D, 0.35 ± 0.81D 였다. 도난시군에서는술전전면, 후면, 전체난시는 -0.48 ± 0.46D, 0.26 ± 0.09D, -0.51 ± 0.65D 였으며술후 2 개월전면, 후면, 전체난시는 -0.17 ± 0.68D, 0.25 ± 0.13D, -0.30 ± 0.55D 였다. 두군에서수술전후전면, 후면, 전체난시에유의한차이가없었다. 수술 2 개월후수술후유발난시량의 vector analysis 시행시직난시군의경우전면난시의 surgically induced astigmatism (SIA) 은 0.03D @ 30 o, 전체난시의 SIA 가 0.07D @ 74 o 였으며도난시군의경우전면난시의 SIA 는 0.27D @ 100 o, 전체난시의 SIA 가 0.36D @ 86 o 로측정되었다. 결론 : 술전전체각막난시가 1.0D 미만일경우후면난시가수술후유발난시량의예측및술후전체난시에미치는영향은적을것으로생각된다. < 대한안과학회지 2015;56(11):1712-1719> 1719