= 증례보고 = 펨토초레이저를이용한백내장수술과고식적백내장수술비교 대한안과학회지 2013 년제 54 권제 8 호 J Korean Ophthalmol Soc 2013;54(8):1227-1235 pissn: 0378-6471 eissn: 2092-9374 http://dx.doi.org/10.3341/jkos.2013.54.8.1227 이우석 한상엽 이경헌 성모안과병원 목적 : 고식적백내장수술과비교한펨토초레이저를이용한백내장수술의임상결과및효율성을알아보았다. 대상과방법 : 펨토초레이저를이용하여백내장수술을시행받은군 (31 안 ) 과고식적백내장수술을시행받은군 (30 안 ) 의최대교정시력, 구면대응치, 수술유발난시도, 각막및안구난시, 고위수차, Strehl ratio, Ocular scatter index, 수정체낭원형절개의직경, 시축과수정체낭원형절개중심사이의거리, 평균절대오차, 유효초음파시간, 평균초음파세기, 수술시간등을비교하였다. 결과 : 최대교정시력, 구면대응치, 수술유발난시, 각막및안구난시, 고위수차, Strehl ratio, Ocular scatter index, 유효초음파시간, 평균초음파세기, 수술시간은두군간통계학적으로유의한차이는없었지만수정체낭원형절개, 시축과수정체낭원형절개의중심사이의거리, 인공수정체의경사도는두군간통계학적의미있는차이를보였다. 결론 : 펨토초레이저를이용한백내장수술은고식적백내장수술보다더일정하고정확한수정체낭원형절개및더나은인공수정체의위치적안정성을보였다. < 대한안과학회지 2013;54(8):1227-1235> 백내장수술은안과의사들에의해가장보편적으로시행되고있는수술중하나로절개, 수정체낭원형절개, 수력분리술과수력분층술, 렌즈분할, 수정체유화술, 인공수정체삽입술의단계로이루어진다. 접힘인공수정체의도입으로이전의넓었던절개창대신점점더작은각막절개창을통한수술이가능해져염증등의합병증감소와무봉합상태로창상치유및각막난시를최소화할수있게되었고 1 통조림따기낭절개 (can-opener capsulotomy) 에서연속적이고둥근수정체낭원형절개로진보하여수술중방사상파열 (radial tear) 에대한저항력을가지고, 인공수정체의낭내삽입이용이하게되었으며, 2,3 phaco prechopper를이용해서수정체핵을분리시키는방법이도입되어초음파유화기의첨단부 (tip) 에서발생하는열과기계적조작에의한안내조직손상, 각막내피세포의 4 손상, 후낭파열등의합병증을감소시킬수있게되었다. 이처럼환자들의보다나은시력의질향상을위해수술방 Received: 2012. 12. 15. Revised: 2013. 3. 13. Accepted: 2013. 5. 18. Address reprint requests to Sang Youp Han, MD Sungmo Eye Hospital, #409-1 Haeun-daero, Haeundae-gu, Busan 612-823, Korea Tel: 82-51-743-0775, Fax: 82-51-743-0776 E-mail: medicalhan@hanmail.net * This study was presented as a narration at the 108th Annual Meeting of the Korean Ophthalmology Society 2012. 법이계속발전하고있으며최근각막절개, 수정체낭원형절개, 렌즈분할을정확하게시행하기위해펨토초레이저가백내장수술에도입되어임상에서사용되고있다. 펨토초레이저를이용한수술은주변조직의손상없이정확한수술절개를가능하게하여안과수술에서상당한기술적진보를가져왔으며주로라식수술에서각막절편생성시에사용되고있으나최근백내장수술에접목되어투명각막절개시투명각막터널을정확하게만들수있어서수정체유화술을시행하기용이하며, 정확한직경과대칭적이고일정한모양의수정체낭원형절개를만들어인공수정체의위치적안정성을가지게되었고, 미리수정체핵을분할하여백내장수술을용이하게시행할수있게되었다. 펨토초레이저를이용한백내장수술이외국에서뿐만아니라최근국내에서도도입되어사용되고있는추세인데, 국내에서아직까지결과에대한보고가없어이에대한연구를실시하였다. 이에저자들은펨토초레이저를이용하여각막절개, 수정체낭원형절개, 렌즈분할을시행받은펨토초레이저를이용한백내장수술군과고식적백내장수술군의수술결과를비교분석하였다. 대상과방법 2012 년 6 월부터 2012 년 7 월까지본원안과에서, 한명의 www.ophthalmology.org 1227
- 대한안과학회지 2013 년제 54 권제 8 호 - 술자 (KH Lee) 에의해펨토초레이저를이용한백내장수술또는고식적백내장수술을받은환자들을대상으로의무기록을후향적으로조사하였다. 술전에나안시력및최대교정시력, 구면대응치 (spherical equivalent), 안압을측정하였고, 자동굴절검사, 세극등현미경검사, 안저검사를포함한안과적검사를시행하였다. 시력은통계분석을위하여스넬렌시력을 logarithm of the minimal angle resolution (logmar) 으로변환하여비교분석하였다. 인공수정체의도수를결정하기위해숙련된검사자를통해 IOL master (Carl Zeiss Meditec, Dublin, USA) 를이용하여안축길이및각막굴절력을측정하였고 SRK/T 공식을이용하여인공수정체도수를결정하였다. KR-1W (Topcon Corp., Tokyo, Japan) 안내수차계를사용하여술전과술후 1개월에 4 mm와 6 mm 직경의각막에서각막난시, 안구난시, 고위수차를측정하였다. Optical Quality Analysis System (OQAS) (Visiometrics SL, Terrassa, Spain) 을이용하여술전과술후 1개월에 Strehl ratio, Objective scatter index (OSI) 를측정하여두군간시력의질을평가하였다. 펨토초레이저를이용한백내장수술은 LenSX (Alcon LenSX, Texas, USA) 를이용하였으며투명각막절개창 (clear corneal incision) 및보조절개창 (side-port corneal incisions), 수정체낭원형절개, 렌즈분할의단계에서사용되었다. 투명각막절개창의길이는 2.2 mm, 보조절개창의길이는 1.0 mm, 수정체낭원형절개의직경은 5.0 mm, 렌즈분할의단계에서수직, 수평길이는각각 5.2 mm로설정하였다. 고식적백내장수술에서도투명각막절개창의길이는 2.2 mm, 보조절개창의길이는 1.0 mm로하였으며, 경험많은술자에의해수정체낭원형절개는직경 5.0 mm가되도록노력하였다. 모든백내장수술은국소점안마취 (4% lidocaine and 0.5% proparacaine hydrochloride (Alcaine, Alcon, USA)) 후시행하였다. 펨토초레이저를이용한백내장수술의경우, 동일한술자가펨토초레이저에의해미리형성된투명각막절개창및보조절개창을확인후점탄물질 (viscoelastic) 을전방내에채워넣었다. 펨토초레이저에의해이미만들어진수정체낭원형절개의범위를확인한후낭집게를이용하여수정체낭의방사상파열없이전낭의절개된부분을조심스럽게제거하였다. 평형생리식염수를사용하여수력분리술및수력분층술을시행한후펨토초레이저에의해수정체핵이 4등분된것을다시한번더 Akahoshi prechopper 를이용하여분할하였다. 초음파유화기는 Infinity (Alcon, Fort Worth, USA) 를사용하여핵의수정체유화술과피질 흡입을시행하였다. 이후점탄물질로전방을다시채우고인공수정체를삽입하였다. 관류흡인으로점탄물질을제거하고적절한안압을확인한후각막봉합을시행하지않고기질수화로창상을폐쇄하였다. 고식적백내장수술의경우, 수술순서는같으나술자가직접각막절개, 수정체낭원형절개, phaco chop을시행하였다. 모든대상환자들은수술전에양안산동상태에서세극등현미경검사를시행하여 LOCS (lens opacities classification system) Ⅲ 분류에의해핵경화정도 (nuclear opalescence, NO) 에따라백내장정도를분류하였으며수술시다양한초음파세기로작동한총초음파시간을 100% 초음파세기작동시로환산한시간인유효초음파시간, 평균초음파세기, 수술시간을측정하여두군을비교하였다. 수술로인해유발된난시도 (surgically induced astigmatism: SIA) 는 Holladay-Cravy-Koch 공식 5 에수술후 1개월에측정한각막곡률값을대입하여산출하여두군을비교하였다. 술후 1개월에 Casia SS-1000 OCT (Tomey, Nagoya, Japan) 로수정체낭원형절개의직경, 시축 (visual axis) 과수정체낭원형절개중심사이의거리, 인공수정체의경사도를분석하였다. 수정체낭원형절개의직경은 Casia SS-1000 OCT로직접측정하였으며인공수정체의경사도는두전방각을이은선 (angle to angle) 과인공수정체의광학부단면이이루는각으로평가하였다. 시축과수정체낭원형절개중심사이의거리는간접적으로구하여분석하였다. Casia SS-1000 OCT 로시축에서수정체낭원형절개중심사이의상대적거리를평가할수있으며, 수평방향 (X) 거리평가는우안에서코쪽, 좌안에서귀쪽에위치하면양의값, 반대방향이면음의값으로표기되고, 수직방향 (Y) 거리평가는시축보다위쪽은양의값, 아래쪽은음의값으로표기되어수평방향 (X) 의제곱과수직방향 (Y) 의제곱의합에서제곱근을구하여시축과수정체낭원형절개의중심사이의거리를간접적으로구하여비교하였다. 수술 1개월후현성굴절검사를시행하여굴절력 (spherical equivalent (SE)) 을측정하였다. 수술전예측굴절력에서수술 1개월후측정된실제굴절력의차를실제오차 (numeric error) 로간주하고실제오차의절대값을절대오차 (absolute error) 로그평균을평균절대오차 (mean absolute error (MAE)) 로정의하여두군간의평균절대오차를비교분석하였다. 자료의분석은 SPSS v 12.0 (SPSS INC., Chicago, USA) 을이용하여시행하였다. 술전및술후두군간의측정치비교는 Mann-Whitney U test를이용하여비교하였고, 통계적유의성은 p<0.05 로하였다. 1228 www.ophthalmology.org
- 이우석외 : 펨토초레이저를이용한백내장수술 - 결과 총 61명 (61안) 을대상으로하였으며이중남자가 27명, 여자가 34명이었고, 펨토초레이저를이용한백내장수술을시행받은군은 31명 (50.8%) 으로남자 12명, 여자 19명이었으며평균나이는 67.03 ± 12.10세였다. 고식적백내장 수술을시행받은군은 30명 (49.2%) 으로남자 15명, 여자 15명이었고평균나이는 68.39 ± 9.60세였다 (Table 1). 술전최대교정시력 (logmar) 은각각 0.33 ± 0.30, 0.43 ± 0.47로차이를보이지않았고 (p=0.06), 술후최대교정시력은수술 1주후 0.09 ± 0.15, 0.08 ± 0.08, 1개월후 0.06 ± 0.12, 0.07 ± 0.08, 2개월후 0.01 ± 0.02, 0.08 Table 1. Preoperative characteristics of eyes for laser refractive cataract surgery with a femtosecond laser group and conventional phacoemulsification group Characteristic FS laser group Conventional group p-value Number of eyes (patients) 31 (31) 30 (30) 0.842 Mean age (years) 67.03 ± 12.10 68.39 ± 9.60 0.733 Gender no. (%) Male 12 (38.7%) 15 (50.0%) 0.545 Female 19 (61.3%) 15 (50.0%) 0.611 MR spherical equivalent (D) -0.74 ± 3.93-1.05 ± 3.14 0.065 Axial length (mm) 24.34 ± 1.60 23.62 ± 0.96 0.449 Endothelial cell density (mm 2 ) 2734.65 ± 333.80 2699.55 ± 364.17 0.677 Values are presented as mean ± SD. FS = femtosecond; MR = manifest refraction; D = diopter. Table 2. Preoperative and postoperative visual acuity BCVA (log MAR) FS laser group Conventional group p-value Preoperative 0.33 ± 0.3 0.43 ± 0.47 0.060 Postoperative 1 week 0.09 ± 0.15 0.08 ± 0.08 0.643 0.06 ± 0.12 0.07 ± 0.08 0.233 Postoperative 2 months 0.01 ± 0.02 0.08 ± 0.09 0.350 Values are presented as mean ± SD. BCVA = best corrected visual acuity; FS = femtosecond. A Diopter 0.6 0.234* 0.56 B Diopter 1.5 0.5 0.4 0.3 0.2 0.1 0 0.43 FS laser group Conventional group 1 0.5 0 0 10 20 30 FS laser group Patients Diopter 1.5 1 0.5 0 0 10 20 30 Conventional group Patients Figure 1. Comparison (A) and distribution (B) of surgically induced astigmatism between laser refractive cataract surgery with a femtosecond laser and conventional phacoemulsification at postoperative 1 month. * p-value = statistical significance was calculated by Mann-Whitney test. www.ophthalmology.org 1229
- 대한안과학회지 2013 년제 54 권제 8 호 - Table 3. Preoperative and postoperative ocular aberrations were measured at the 4.0 mm and 6.0 mm optical zone. Aberration parameters were included ocular astigmatism, corneal astigmatism, and total high order aberration by KR-1W aberrometer FS laser group Conventional group p-value Astigmatism (4 mm optical zone) Preoperative Ocular -1.33 ± 0.74-1.20 ± 0.74 0.432 Corneal -1.24 ± 0.92-1.08 ± 0.58 0.732 Ocular -0.82 ± 0.53-0.89 ± 0.64 0.453 Corneal -1.11 ± 0.72-0.98 ± 0.63 0.395 Astigmatism (6 mm optical zone) Preoperative Ocular -1.33 ± 0.74-1.24 ± 0.78 0.563 Corneal -0.88 ± 0.64-0.77 ± 0.44 0.782 Ocular -0.87 ± 0.59-0.76 ± 0.55 0.343 Corneal -0.77 ± 0.54-0.73 ± 0.46 0.802 Total high order aberration (4 mm optical zone) Preoperative Ocular 0.24 ± 0.11 0.27 ± 0.16 0.796 Corneal 0.18 ± 0.08 0.15 ± 0.05 0.164 Internal 0.20 ± 0.11 0.24 ± 0.18 0.957 Ocular 0.18 ± 0.09 0.20 ± 0.10 0.330 Corneal 0.19 ± 0.10 0.19 ± 0.09 0.902 Internal 0.12 ± 0.05 0.13 ± 0.06 0.914 Total high order aberration (6 mm optical zone) Preoperative Ocular 0.69 ± 0.34 0.86 ± 0.28 0.011 Corneal 0.50 ± 0.21 0.46 ± 0.10 0.574 Internal 0.58 ± 0.32 0.66 ± 0.41 0.563 Ocular 0.63 ± 0.25 0.77 ± 0.30 0.138 Corneal 0.50 ± 0.13 0.52 ± 0.18 0.865 Internal 0.43 ± 0.18 0.43 ± 0.18 0.777 Values are presented as mean ± SD. A 1.00 FS laser group Conventional group B 10.00 FS laser group Conventional group Strehl ratio 0.80 0.60 0.40 0.20 0.17 0.287* 0.08 0.43 0.627* 0.18 Objective scatter index 8.00 6.00 4.00 2.00 4.78 0.970* 5.17 1.43 0.201* 1.7 0.00 0.00 Preoperative Preoperative Figure 2. Preoperative and postoperative parameters (Strehl ratio (A), Objective scatter index (B)) in Optical Quality Analysis System between laser refractive cataract surgery with a femtosecond laser and conventional phacoemulsification at postoperative 1 month. * p-value = statistical significance was calculated by Mann-Whitney test. ± 0.09로각각측정되었으며유의한차이를보이지않았다 (Table 2). 수술로인해유발된난시도 (SIA) 는펨토초레이저를이 용하여백내장수술을시행받은군 (0.43 ± 0.11) 과고식적백내장수술을시행받은군 (0.56 ± 0.38) 사이에통계적으로유의한차이는보이지않았으나펨토초레이저를이 1230 www.ophthalmology.org
- 이우석외 : 펨토초레이저를이용한백내장수술 - A B Figure 3. Comparison (A) and distribution (B) of curvilinear capsulorrhexis size which was measured by Casia SS-1000 OCT between laser refractive cataract surgery with a femtosecond laser and conventional phacoemulsification at postoperative 1 month (B). (A) Diameter of continuous curvilinear capsulorrhexis (mm). (B) Distribution of diameter (mm). * p-value = statistical significance was calculated by Mann-Whitney test. A B Figure 4. The distance from visual axis to the center of continuous curvilinear capsulorrhexis (A) and Intraocular lens positioning (horizontal tilt) (B) between laser refractive cataract surgery with a femtosecond laser and conventional phacoemulsification at postoperative 1 month (B). * p-value = statistical significance was calculated by Mann-Whitney test. www.ophthalmology.org 1231
- 대한안과학회지 2013 년제 54 권제 8 호 - Table 4. Effective phaco time, average phaco power, operation time were analyzed between laser refractive cataract surgery with a femtosecond laser and conventional phacoemulsification Parameters Grading FS laser Conventional p-value Effective phaco time (sec) LOCS III NO 1,2 4.52 ± 2.71 3.4 ± 1.4 0.271 LOCS III NO 3,4 7.38 ± 2.82 8.36 ± 5.34 0.983 LOCS III NO 5,6 14.49 ± 10.14 12.41 ± 4 0.563 Average phaco power (%) LOCS III NO 1,2 19.29 ± 8.16 26.16 ± 2.44 0.181 LOCS III NO 3,4 24.54 ± 5.48 25.33 ± 3.13 0.723 LOCS III NO 5,6 32.39 ± 15.80 26.88 ± 5.11 0.266 OP time (min) LOCS III NO 1,2 13.04 ± 2.45 13.63 ± 2.92 0.639 LOCS III NO 3,4 14.88 ± 2.09 13.57 ± 2.47 0.069 LOCS III NO 5,6 18.13 ± 5.25 16.38 ± 5.10 0.456 Values are presented as mean ± SD. LOCS = lens opacities classification system; NO = nuclear opacity; OP time = operation time. Mean absolute error (diopter) 0.6 0.5 0.4 0.3 0.2 0.1 0 0.29 FS laser group 0.016* 0.51 Conventional group Figure 5. Difference between predicted and achieved postoperative spherical equivalent refraction. Mean absolute error was analyzed 1 month after surgery. * p-value = statistical significance was calculated by Mann-Whitney test. 용한백내장수술을시행받은군에서고식적백내장수술을시행받은군에비해일관된분포양상을보였다 (Fig. 1). 술전후 KR-1W 안구수차계를이용하여 4 mm 및 6 mm 동공크기에서측정된각막난시, 안구난시및고위수차는두군간유의한차이를보이지않았다 (Table 3). 술전측정한 Strehl ratio 는펨토초레이저를이용하여백내장수술을시행받은군 (0.17 ± 0.14) 과고식적백내장수술을시행받은군 (0.08 ± 0.05) 사이에유의한차이가없었으며술후 1개월에각각 0.43 ± 0.33, 0.18 ± 0.11로두군간통계학적유의한차이를보이지않았다. Objective scatter index는술전각각 4.78 ± 3.05, 5.17 ± 4.11, 술후 1개월에각각 1.43 ± 1.12, 1.70 ± 1.43로두군간유의한차이를보이지않았다 (Fig. 2). 술후 1개월에측정한수정체낭원형절개의직경은펨토초레이저를이용하여백내장수술을받은군 (5.21 ± 0.61) 과고식적백내장수술을시행받은군 (5.89 ± 1.48) 사이에통계적으로유의한차이를보였으며 (p=0.031), 펨토초 레이저를이용하여백내장수술을시행받은군에서보다일관된분포양상을보였다 (Fig. 3). 시축과수정체낭원형절개의중심사이의거리는각각 0.16 ± 0.04, 0.76 ± 0.48 로두군간유의한차이를보였으며 (p=0.010), 인공수정체의경사도는각각 1.23 ± 0.55 o, 2.56 ± 0.1.73 o 로두군간통계학적으로유의한차이를보였다 (p-value=0.037) (Fig. 4). 술전, 술후 1주, 1개월, 2개월경과관찰시구면렌즈대응치는펨토초레이저를이용한백내장수술을받은군에서각각 -0.82 ± 4.14, -0.63 ± 0.96, -0.73 ± 1.09, -0.71 ± 0.97 로측정되었으며고식적백내장수술을시행받은군에서각각 -0.81 ± 2.93, -0.73 ± 0.96, -0.75 ± 0.95, -0.70 ± 0.99 로측정되어두군간유의한차이를보이지않았다 (p=0.571, p=0.358, p=0.544, p=0.607). 평균절대오차는펨토초레이저를이용한백내장수술을받은군에서 0.29 ± 0.12, 고식적백내장수술을시행받은군에서 0.51 ± 0.36로두군간통계학적으로유의한차이를보였다 (p=0.016) (Fig. 5). 수술시기록된유효초음파시간 (effective phaco time), 평균초음파세기 (average phaco power), 수술시간은두군간유의한차이를보이지않았다 (Table 4). 고찰 노령인구가증가함에따라백내장수술은매년증가하고있으며, 환자들에게보다나은시력의질향상을위해여러가지수술방법, 인공수정체, 임상적진단장비, 수술장비에대한연구가계속발전하고있다. 라식수술의각막절편형성, 난시교정을위한주변각막이완절개 (peripheral corneal relaxing incisions), 각막이식에사용되었던펨토초레이저가최근백내장수술에접목되어해외뿐만아니라국내에서도사용되고있다. 펨토초레이저를이용하여각막절개, 수정체낭원형절개, 렌즈분할을 1232 www.ophthalmology.org
- 이우석외 : 펨토초레이저를이용한백내장수술 - 시행할수있으며고식적백내장수술에비해여러가지장점을가진다고알려졌다. 6-10 본연구에서각막및안구전체의수차, 고위수차분석을통하여펨토초레이저를이용하여백내장수술을시행받은군과고식적백내장수술을시행받은군을비교하였으나두군간유의한차이를보이지않았다. 이는두군모두투명각막절개창의크기와보조절개창의길이가같고, 수술로인한난시유발 (SIA) 이작은이측투명각막절개를시행하였기때문으로추측된다. OQAS는 double-pass 방식을사용하여 modulation transfer function (MTF), Strehl ratio, OSI 등을측정하게되며, 11 Strehl ratio는완전한 zero-aberration 상태에서최고값 1을가지며수차 (aberration) 증가시 Strehl ratio는감소하게되며, OSI는안내빛분산 (intraocular scattered light) 을평가하는수치로분산정도가커지면 OSI는증가하게된다. 12 본연구에서는백내장수술후시력의질을평가하기위해 Strehl ratio와 OSI로두군을비교하였으며, 두군간통계학적차이를보이지않았다. 이는두군간난시차이가없었고, 시력에질에영향을줄수있는인공수정체의위치이탈과경사도가두군간통계학적으로차이가있었지만 Holladay et at 13 은경사도가 5 o 이상, Piers et al 14 은위치이탈이 0.8 mm, 경사도는 10 o 이상차이를보여야시력의질에영향을미친다고하였으며, 본연구에서는위치이탈은평균 0.60 mm, 경사도는평균 1.33 o 차이를보여두군간시력의질에차이가없었던것으로생각한다. 수정체낭원형절개의크기가너무크면수정체낭원형절개술시행도중 anterior zonules의종지부위에손상을줄수있고, 수력분리술또는초음파유화술을시행할때수정체핵이전방으로잘탈출되어수술이어려워지거나각막내피세포에손상을줄수있으며, 인공수정체의광학부가수정체낭내에고정되지못하고상대적으로큰수정체낭원형절개부위밖으로쉽게이탈됨으로써홍채후유착이나인공수정체의동공물림및중심이탈현상등의문제점이발생할수있다. 반면수정체낭원형절개의크기가너무작으면수정체핵을다루기가어렵고수술기구가출입하는절개창근처의수정체피질을제가하기가어려우며, 수술후절개창의수축으로인한유효광학면적의감소와수정체낭폐쇄증후군 (capsular block syndrome) 이발생하는요인이된다. 따라서수정체낭원형절개는삽입할인공수정체의광학부직경보다 0.5-1.0 mm 정도작게하는것이일반적이며대개직경 5.0-5.5 mm 정도로시행하게된다. 본연구에서도수정체낭원형절개의직경을 5.0 mm로시행하였다. 하지만수정체낭원형절개의직경이적당하더라도, 직접술자에의해시행된수정체낭원형절개 (manual capsulorrhexis) 는대략 1% 정도에서수정체낭의방사상파열이발생할수있으며, 15 수정체낭원형절개의직경및모양이다양하게나타날수있다. 수정체낭원형절개의모양이대칭적이지않으면수술후전낭의비대칭적수축 (asymmetric capsular shrinkage) 으로인공수정체의위치변화를야기할수있으며 16 인공수정체의중심이시축과일치하지않고다양한위치에있을경우굴절력의변화및시력의질이감소할수있다. 17-21 그러므로일정한크기의직경과대칭적모양은수정체낭원형절개에있어서상당히중요한요소이다. Kinga et al 6 은 20명 20안에대해펨토초레이저를이용한백내장수술이고식적백내장수술보다더정확한수정체낭원형절개의직경과일정한크기및모양을보였다고보고하였으며또다른연구에서도펨토초레이저를이용한백내장수술이고식적백내장수술보다수정체낭원형절개가보다정확하고경계가균일하다고하였다고보고하였다. 7 본연구에서도펨토초레이저를이용한백내장수술군에서더정확한수정체낭원형절개의직경과일정한크기를보였지만펨토초레이저를이용한백내장수술시수정체낭원형절개의직경을 5.0 mm로설정하였으나수술후 1개월에측정한수정체낭원형절개의직경은 5.21 ± 0.61 mm로예측된값과다소차이가있었다. 이오차는술전수정체모양이볼록하지만수정체핵제거와인공수정체의삽입으로수정체낭이편평해져직경이증가했거나수정체낭원형절개의직경을측정한 Casia SS-1000 OCT 의측정오차로생각한다. Miháltz et al 8 은펨토초레이저를이용하여백내장수술을받은 48안과고식적백내장수술을받은대조군에대한연구에서펨토초레이저를이용하여백내장수술을받은군에서인공수정체의경사도가낮았다고보고하였고, Akahoshi, et al 22 도펨토초레이저를이용하여백내장수술을받은군이고식적백내장수술을받은군에비해인공수정체의경사도및중심이탈 (decentration) 이낮았으며이는수정체낭원형절개의직경과일정한크기가인공수정체의위치적안정성에기여한다고보고하였다. 본연구에서도인공수정체의경사도및중심이탈이펨토초레이저를이용한백내장군에서낮게측정되어인공수정체의위치가더안정적이었다. 펨토초레이저를이용한백내장수술시대칭적인수정체낭원형절개가가능하여인공수정체의위치변화를감소시킬수있으며 6,9 인공수정체의위치적안정성은술전예측굴절력과술후측정된굴절력사이의오차를줄일수있다. Filkorn et al 10 은펨토초레이저를이용하여백내장수술을시행받은 77명 77안과고식적백내장수술을시행받은 55명 57안을대상으로평균절대오차 (MAE) 를비교하였으 www.ophthalmology.org 1233
- 대한안과학회지 2013 년제 54 권제 8 호 - 며, 펨토초레이저를이용한백내장수술군 (0.38 ± 0.28) 이고식적백내장수술군 (0.50 ± 0.38) 보다유의하게작았으며 (p=0.040), 본연구에서도같은결과를보였다. LOCS Ⅲ 분류에의해핵경화정도에따라백내장정도를분류하여수술시기록된유효초음파시간, 평균초음파세기를비교하였다. 핵경화정도가심할수록유효초음파시간과평균초음파세기는증가하며, 23 돼지눈을대상으로한실험에서펨토초레이저를이용한백내장수술이고식적수술보다유효초음파시간은 51%, 평균초음파세기는 43% 감소시켰다는연구결과가있다. 7 본연구에서핵경화정도가심할수록유효초음파시간과평균초음파세기는증가하였지만핵경화정도가비슷할경우, 펨토초레이저를이용한백내장수술과고식적인백내장수술에서두군간차이를보이지않았으며이는사람에대한결과로동물실험과는다른결과를보였다. 또한펨토초레이저를이용한백내장수술의경우펨토초레이저를이용하여수정체핵을미리 4 등분하였지만렌즈가완전히분할되지않아다시한번더 Akahoshi prechopper를이용하여분할했기때문에, 고식적백내장수술군과비교에서두군간수술시간의통계학적차이는없었다. 펨토초레이저후백내장수술을위해수술실로이동하는과정에서이동시간이발생하며그사이에감염의위험성이증가하는단점이있다. 수정체낭원형절개는백내장수술에서가장중요한단계중하나로이과정을펨토초레이저를이용하여직경과모양이일정한수정체낭원형절개를만들수있다. 이는시축과수정체낭원형절개의중심사이의거리및인공수정체의경사도를감소시켜인공수정체의위치적안정성을가져다줄수있어, 점점더시력의질적향상을원하는요즘더안정적이고예측가능한수술방법으로생각한다. REFERENCES 1) Fine IH. Architecture and construction of a self-sealing incision for cataract surgery. J Cataract Refract Surg 1991;17 Suppl:672-6. 2) Gimbel HV, Neuhann T. Development, advantages, and methods of the continuous circular capsulorhexis technique. J Cataract Refract Surg 1990;16:31-7. 3) Colvard DM, Dunn SA. Intraocular lens centration with continuous tear capsulotomy. J Cataract Refract Surg 1990;16:312-4. 4) Kránitz K, Miháltz K, Sándor GL, et al. Intraocular lens tilt and decentration measured by scheimpflug camera following manual or femtosecond laser-created continuous circular capsulotomy. J Refract Surg 2012;28:259-63. 5) Holladay JT, Cravy TV, Koch DD. Calculating the surgically induced refractive change following ocular surgery. J Cataract Refract Surg 1992;18:429-43. 6) Kránitz K, Takacs A, Miháltz K, et al. Femtosecond laser capsulotomy and manual continuous curvilinear capsulorrhexis parameters and their effects on intraocular lens centration. J Refract Surg 2011;27:558-63. 7) Nagy Z, Takacs A, Filkorn T, Sarayba M. Initial clinical evaluation of an intraocular femtosecond laser in cataract surgery. J Refract Surg 2009;25:1053-60. 8) Miháltz K, Knorz MC, Alió JL, et al. Internal aberrations and optical quality after femtosecond laser anterior capsulotomy in cataract surgery. J Refract Surg 2011;27:711-6. 9) Nagy ZZ, Kránitz K, Takacs AI, et al. Comparison of intraocular lens decentration parameters after femtosecond and manual capsulotomies. J Refract Surg 2011;27:564-9. 10) Filkorn T, Kovács I, Takács A, et al. Comparison of IOL power calculation and refractive outcome after laser refractive cataract surgery with a femtosecond laser versus conventional phacoemulsification. J Refract Surg 2012;28:540-4. 11) Martínez-Roda JA, Vilaseca M, Ondategui JC, et al. Optical quality and intraocular scattering in a healthy young population. Clin Exp Optom 2011;94:223-9. 12) Nochez Y, Majzoub S, Pisella PJ. Effect of residual ocular spherical aberration on objective and subjective quality of vision in pseudophakic eyes. J Cataract Refract Surg 2011;37:1076-81. 13) Holladay JT, Piers PA, Koranyi G, et al. A new intraocular lens design to reduce spherical aberration of pseudophakic eyes. J Refract Surg 2002;18:683-91. 14) Piers PA, Weeber HA, Artal P, Norrby S. Theoretical comparison of aberration-correcting customized and aspheric intraocular lenses. J Refract Surg 2007;23:374-84. 15) Marques FF, Marques DM, Osher RH, Osher JM. Fate of anterior capsule tears during cataract surgery. J Cataract Refract Surg 2006;32:1638-42. 16) Ohmi S. Decentration associated with asymmetric capsular shrinkage and intraocular lens size. J Cataract Refract Surg 1993;19:640-3. 17) Lakshminarayanan V, Enoch JM, Raasch T, et al. Refractive changes induced by intraocular lens tilt and longitudinal displacement. Arch Ophthalmol 1986;104:90-2. 18) Atchison DA. Refractive errors induced by displacement of intraocular lenses within the pseudophakic eye. Optom Vis Sci 1989; 66:146-52. 19) Erickson P. Effects of intraocular lens position errors on postoperative refractive error. J Cataract Refract Surg 1990;16:305-11. 20) Kozaki J, Tanihara H, Yasuda A, Nagata M. Tilt and decentration of the implanted posterior chamber intraocular lens. J Cataract Refract Surg 1991;17:592-5. 21) Korynta J, Bok J, Cendelin J. Changes in refraction induced by change in intraocular lens position. J Refract Corneal Surg 1994; 10:556-64. 22) Akahoshi T. Phaco prechop: manual nucleofracture prior to phacoemulsification. Op Tech Cataract Ref Surg 1998;1:69-91. 23) Bencić G, Zorić-Geber M, Sarić D, et al. Clinical importance of the lens opacities classification system III (LOCS III) in phacoemulsification. Coll Antropol 2005;29 Suppl 1:91-4. 1234 www.ophthalmology.org
- 이우석외 : 펨토초레이저를이용한백내장수술 - =ABSTRACT= Comparison of Laser Refractive Cataract Surgery with a Femtosecond Laser Versus Conventional Phacoemulsification Woo Seok Lee, MD, Sang Youp Han, MD, Kyung Hun Lee, MD Sungmo Eye Hospital, Busan, Korea Purpose: To evaluate the surgical results and efficacy of laser refractive cataract surgery with a femtosecond laser compared with conventional phacoemulsification. Methods: Thirty-one eyes from 31 patients underwent laser refractive cataract surgery (femtosecond laser group), and conventional cataract surgery with phacoemulsification was performed in 30 eyes from 30 patients (conventional group). Best corrected visual acuity, spherical equivalent, surgical induced astigmatism, corneal and ocular astigmatism, total high order aberration, Strehl ratio, objective scatter index, diameter of continuous curvilinear capsulorrhexis (CCC), distance from visual axis to the center of CCC, intraocular lens (IOL) tilt, mean absolute error, effective phaco time, average phaco power and operation time were measured to compare the 2 groups. Results: No significant differences were found between best corrected visual acuity, spherical equivalent, surgical induced astigmatism, corneal and ocular astigmatism, total high order aberration, Strehl ratio, objective scatter index, mean absolute error, effective phaco time, average phaco power or operation time. Significant differences were found in the diameter of CCC, distance from visual axis to the center of CCC, and IOL tilt. Conclusions: Results of laser refractive cataract surgery with a femtosecond laser showed more precise CCC, and more stable IOL position than conventional cataract surgery. J Korean Ophthalmol Soc 2013;54(8):1227-1235 Key Words: Cataract, Femtosecond laser, LenSx Address reprint requests to Sang Youp Han, MD Sungmo Eye Hospital #409-1 Haeun-daero, Haeundae-gu, Busan 612-823, Korea Tel: 82-51-743-0775, Fax: 82-51-743-0776, E-mail: medicalhan@hanmail.net www.ophthalmology.org 1235