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1 대한안과학회지 2009 년제 50 권제 4 호 J Korean Ophthalmol Soc 2009;50(4): DOI : /jkos = 증례보고 = 접수번호 : 라섹수술후각막및앞방의변화 : Pentacam 분석 박진형 1 강자헌 2 진경현 1 경희대학교의과대학안과학교실 1, 경희대학교동서신의학병원 2 목적 : 술후잠재성각막확장증여부를알기위해서 Pentacam 을이용하여라섹 (LASEK) 수술전후의각막및앞방의변화를알아보고자하였다. 대상과방법 : 36 명 71 안을대상으로라섹수술을시행하였다. 수술전및수술후 1 개월째에 Pentacam (Oculus, Germany) 을이용하여각막앞, 뒷면의비구면도 (Q-value) 및전위도, 중심각막두께, 앞방깊이, 앞방부피를측정하였다. 결과 : 수술전후각막뒷면의비구면도및전위도는유의한차이를보이지않았다 (p=0.668, p=0.101). 수술후앞방깊이, 앞방각및부피는각각 mm, 0.983, 7.21 mm 3 감소하였다 (p=0.000). 수술전후중심각막두께, 각막앞면의비구면도및전위도는유의한차이를보였다 (p=0.000). 결론 : Pentacam 을이용하여라섹수술전후전방및각막의변화를비교한결과, 1 개월째각막앞면은유의한변화를보이는반면, 각막뒷면은유의한변화를보이지않았고, 앞방깊이, 앞방각및부피가감소하는변화를보였지만장기간경과관찰이필요할것으로생각된다. < 대한안과학회지 2009;50(4): > LASEK (Laser subepithelial keratomileusis: LASEK) 은 LASIK (Laser in situ keratomileusis: LASIK) 에서나타날수있는각막절편유리, 각막절삭기의불완전한통과, 각막절편의주름, 각막확장증등의합병증과 PRK 후에나타날수있는통증, 유루, 시력회복지연을줄일수있어널리사용되고있다. 1 굴절교정수술이흔하게시행되어짐에따라굴절교정수술후각막형태변화에대하여많은연구가이루어지고있다. 2 Pentacam은비침습적으로앞방각, 앞방깊이, 앞방부피를측정할수있는검사기구로앞방척도를측정하는데있어서높은신뢰도를가지며, 3 A-scan 초음파, 4 AC-Master (Carl Zeiss Meditech, Jena, Germany), 5 IOL Master (Carl Zeiss Meditech, Jena, Germany) 6 와유사한측정치를보인다. 그러나 Elbaz et al 7 은 Pentacam은앞방깊이측정에있어 A-scan 초음파와 IOL master와다른측정결과를보여호환이 불가능하다고하였다. 하지만 Shanker et al 8 은 Pentacam 은 앞방측정에있어서높은신뢰도와더불어뛰어난재현성을보인다고하였다. 접수일 : 2008 년 9 월 18 일 심사통과일 : 2008 년 12 월 3 일 통신저자 : 진경현서울시동대문구회기동 1 경희대학교병원안과 Tel: , Fax: khjinmd@khmc.or.kr * 본논문의요지는 2008 년대한안과학회제 99 회춘계학술대회에서포스터로발표되었음. Pentacam은각막뒷면측정에있어높은재현성을보여, 9 각막뒷면의상승을평가하여원추각막, 잠재성원추각막을정상각막과감별하는데유용하며, 이는 LASIK 수술후각막확장증예방에도움이된다. 10,11 또한, Emre et al 12 은 Pentacam을이용한측정결과원추각막이진행함에따라가장얇은각막두께가얇아지고, 각막부피가작아지며, 앞방척도들이작아지는변화를보인다고하였다. 굴절교정수술후각막및앞방의변화에대한이전의연구에서 LASIK 수술후각막의비구면도가증가하며, 13 Ciolino et al 14 은 Pentacam을이용하여 LASIK 수술후단기, 장기간추적결과각막뒷면의유의한전방전위는보이지않으며, 이결과는이전의 Orbscan을이용한결과와는다른양상을보인다고하였다. Hashemi and Mehravaran 15 은굴절교정수술후각막뒷면의전위정도평가에있어 Orbscan과 Pentacam의결과가다르며, Orbscan의결과가다소과장된결과를보인다고하였다. 또한, 앞방깊이측정에있어두검사결과에차이를보인다고하였다. LASEK 수술등의굴절교정수술후추적관찰시 Placidodisc 각막지형도, Orbscan, Pentacam, 고속전안부빛간섭단층촬영계등을이용하여술후각막확장증유무, 각막절삭면의위치등을관찰하게된다. 또한, 굴절교정수술후각막앞뒤면의변화및안압의변화에관해서는많은연구가있지만, 앞방의변화에관한연구는흔하지않다. 본연구에서는근시안에서가장흔하게사용되고있는 LASEK 수술을 510

2 - 박진형외 : 라섹수술후전안부변화 - Table 1. The comparison of anterior and posterior corneal asphericity (Q-value) between preoperative and postoperative state (at 1 month after operation) Preoperative-Q * Postoperative-Q Mean±SD (range) Mean±SD (range) p-value Anterior corneal surface ± (-0.55 to 0.15) ± (0.00 to 3.00) Posterior corneal surface ± (-0.25 to 0.72) ± (-0.26 to 0.66) * Preoperative-Q=Preoperative asphericity (Q-value); Postoperative-Q=Postoperative asphericity (Q-value) (at l month after operation); SD=Standard deviation A B Preoperative ashpericity (Q-value) Preoperative ashpericity (Q-value) Figure 1. The scatterplots for corneal asphericity between preoperative and postoperative states (at 1 month after operation). (A) Anterior corneal surface. A prolate anterior corneal surface had changed into an oblate surface after operation. (B) Posterior corneal surface. An asphericity of the posterior cornea was unchanged after operation. 받은환자를대상으로하여 Pentacam으로측정한 LASEK 수술전후의각막및앞방의변화를알아보고자하였다. 대상과방법 대상 2007년 7월부터 2008년 4월까지본원안과에서 LASEK 수술을받은근시외에안과적이상이없는환자들 36명 71안을대상으로하였다. 술전검사술전에안압, 나안시력, 세극등현미경검사, 조절마비제점안후타각적굴절검사, 초음파각막두께측정계검사 (DGH 500BPL, DGH Technology, Inc., Pennsylvania, USA), Scheimpflug 영상검사 (Pentacam, Oculus Inc., Dutenhofen, Germany) 를시행하였다. 수술방법증류수로희석시킨 20% 알코올과 epithelial micro-hoe 를이용하여각막상피를부드럽게벗겨낸후엑시머레이저 (Mel 70 G-scan, Asclepion Meditec, Germany) 조사하였다. 각막기질을평형염류용액으로충분히세척하고관류용주사바늘 (irrigation needle) 을이용하여조심스럽게원위치시키고치료용콘택트렌즈를덮었다. 수술직후 0.5% moxifloxacin (Vigamox, Alcon, USA) 과, 0.01% fluorometholone ( 오큐메토론, 삼일제약 ) 을한방울씩점안하였고술후 1주일간각막상피의재생이끝날 511

3 - 대한안과학회지 2009 년제 50 권제 4 호 - Table 2. The comparison of central corneal thickness between preoperative and postoperative state (at 1 month after operation) (Pentacam parameter) Preoperative thickness Postoperative thickness Mean±SD (range) Mean±SD (range) p-value CCT * (μm) ±30.35 (485 to 618) ±41.18 (381 to 549) * CCT=central corneal thickness; SD=standard deviation. 때까지 0.5% moxifloxacin (Vigamox, Alcon, USA) 과 0.01% fluorometholone( 오큐메토론, 삼일제약 ) 을 6시간마다점안하였으며그후 2주간은 0.01% fluorometholone( 오큐메토론, 삼일제약 ) 을 12시간마다점안하였다. 이후각막혼탁정도에따라 0.01% fluorometholone 점안횟수를조절하였다. 술후검사술후 1개월에안압, 나안시력, 세극등현미경검사, 타각적굴절검사, Scheimpflug 영상검사 (Pentacam, Oculus Inc., Dutenhofen, Germany) 를시행하였다. LASEK 수술전, 술후 1개월째 Pentacam을이용하여측정한각막앞면과뒷면의비구면도 (Q-value), 중심상승 (Central elevation), 중심각막두께, 앞방깊이, 앞방각, 앞방부피를비교하였고, 수술전초음파각막두께측정치와수술전 Pentacam 각막두께측정치를비교하였다. 비구면도 (Q-value) Pentacam을이용하여측정한술전과술후 1개월째각막앞면의비구면도는통계적으로유의한차이를보였다 (p=0.000)(table 1). 각막앞면의비구면도는술전평균 에서술후 1개월째평균 으로변화하여편장한 (Prolate) 면이편원의 (Oblate) 면으로변화하는양상을보였다 (Fig. 1). 술전과술후 1개월째각막뒷면의비구면도는통계적으로유의한차이가없었다 (p=0.668)(table 1). 각막뒷면의비구면도는편원의타원형태가유지되는양상을보였다 (Fig. 1). 중심각막두께 Pentacam을이용하여측정한술전과술후 1개월째중심각막두께는술전에비해중심각막두께가얇아지는양상을보였으며통계적으로유의한차이를보였다 (p=0.000)(table 2). 분류및통계방법 각막중심상승도 통계분석은 SPSS version 13.0 을각막앞면과뒷면의비구면도 (Q-value), 중심상승 (Central elevation), 중심각막두께, 앞방깊이, 앞방각, 앞방부피를 Paired sample t-test 를사용하여비교하였고, 수술전초음파각막두께측정치와수술전 Pentacam 각막두께측정치를 Paired sample t-test 를사용하여비교하였다. p<0.05 를통계적으로유의한결과로보았다. 결과 대상환자의진료기록을후향적으로분석하였다. 총 36명 71안으로남자가 7명 14안, 여자가 29명 57안이었고환자들의평균나이는 28.3세였다. 술전평균구면대응치는 -5.87±2.61 디옵터 ( 범위 -1.75~-13.00) 였고초음파각막두께측정계를이용하여측정한중심각막두께는 ±29.30 μm였다. 술전과술후의비교를위하여기준 best-fit sphere (BFS) 를술전의 BFS로고정하였다. Pentacam을이용하여측정한술전과술후 1개월째각막앞면의전위정도는통계적으로유의한차이를보였다 (p=0.000)(table 3). 각막앞면의전위정도는각막앞면이후방전위하는양상을보였다 (Fig. 2). 술전과술후 1개월째측정한각막뒷면의전위정도는통계적으로유의한차이를보이지않았다 (p= 0.240)(Table 3)(Fig. 2). 앞방척도 Pentacam을이용하여측정한술전과술후 1개월째앞방각, 앞방깊이, 앞방부피는통계적으로유의한차이를보였다 (p=0.001, p=0.000, p=0.000)(table 4). 앞방각이좁아지고, 앞방깊이가얕아지며, 앞방부피가줄어드는양상을보였다 (Fig. 3). 512

4 - 박진형외 : 라섹수술후전안부변화 - Table 3. The comparison of anterior and posterior corneal central elevation between preoperative and postoperative state (at 1 month after operation) Preoperative-CE * Postoperative-CE Mean±SD (range) Mean±SD (range) p-value A-CE (μm) 2.24±1.83 (-1 to 8) ±14.41 (-70 to 9) P-CE (μm) -0.48±2.25 (-5 to 5) -1.06±3.41 (-8 to 7) * Preoperative-CE=Preoperative central elevation; Postoperative-CE=Postoperative central elevation (at l month after operation); A-CE=anterior central elevation; P-CE=posterior central elevation; SD=standard deviation A -8 B Preoperative central elevation Preoperative central elevation Figure 2. The scatterplots for corneal central elevation between preoperative and postoperative states (at 1 month after operation). (A) Anterior corneal surface. Central elevation of anterior corneal surface was lower after operation. (B) Posterior corneal surface. Central elevation of posterior corneal surface was unchanged after operation. 고찰 각막앞면은안구전체에서굴절력을결정하는가장중요한요소로서정상인에서각막앞면은전체굴절력의 80% 를이루고있다. 각막은구형이아닌비구면의형태를띠고있으며, 이의형태를수치화하여비구면도라한다. 이중 Q-value 는대표적인비구면도를나타내는형태요소로서 Q-value 가 0이면원을의미하고, -1에서 0 사이일경우편장한 (prolate) 타원, Q-value가 -1이면포물선 (parabola), -1보다작은경우쌍곡선 (hyperbola), 0보다큰경우편원의타원을의미한다. 16 본연구에서술전의각막앞면의 Q-value 가평균 , 각막뒷면의 Q- value가평균 로앞면은편장한타원의형태, 뒷면은편원의타원의형태를보이고있다. p-factor는비구면도를나타내는형태요소로서 p-factor 는 Q-value 에 1을더한값을가진다. 16 Anera et al 13 은 LASIK 수술후각막의비구면도변화를 p-factor 를이용하여측정하였다. 술전평균 p-factor 는 0.88, 술후 1개월째평균 p-factor 는 1.65였다고보고하였다. 본연구에서각막앞면의 Q-value 는평균 에서 로변화하여편장한타원이편원의타원형태로변하여 Anera et al 과상응하는결과를보였다. 또한, 본연구에서각막뒷면의 Q-value 를측정한결과, 각막뒷면의 Q-value 는평균 에서 로변화하여편원의타원의형태가유지되는결과를보였다. 굴절교정수술후각막확장증에서각막뒷면이앞쪽으로전위되는데, 이전의 Orbscan을이용한연구에서 LASIK 수술후각막뒷면이앞쪽으로전위되는양상을보이며, 이는 LASIK 후잠재성각막확장증을나타낸다고하였으나, 최근 Pentacam을이용한연구에서굴절교정수술후각막뒷면의유의한앞쪽전위는나타나지않는다고하였다. 14,15 Ciolino et al 14 은 LASIK 수술후각막뒷면이 1개월째평 513

5 - 대한안과학회지 2009 년제 50 권제 4 호 - Table 4. The comparison of anterior chamber parameter between preoperative and postoperative state (at 1 month after operation) Preoperative value Postoperative value parameter Mean±SD (range) Mean±SD (range) p-value ACD * (mm) 3.286±0.198 (2.80 to 3.80) 3.198±0.200 (2.72 to 3.75) ACA ( ) ±4.856 (32.9 to 53.9) ±4.816 (31.0 to 52.5) ACV (mm 3 ) ±22.37 (134 to 251) ±23.90 (124 to 242) * ACD=anterior chamber depth; ACA=anterior chamber angle; ACV=anterior chamber volume; SD=standard deviation A 30.0 B Preoperative anterior chamber depth Preoperative anterior chamber angle C Preoperative anterior chamber volume Figure 3. The scatterplots for anterior chamber parameters between preoperative and postoperative states (at 1 month after operation). (A) Anterior chamber depth. Anterior chamber depth had become shallow after operation. (B) Anterior chamber angle. Anterior chamber angle had become narrow after operation. (C) Anterior chamber volume. Anterior chamber volume had shrunk after operation. 균 μm, 14개월째 μm 앞쪽으로전위한다고하였다. 본연구에서각막뒷면은술전 μm에서술후 1개월째 μm로전위하여통계적으로유의한차이를보이지않지만 Ciolino et al 14 의연구와달리 LASEK 수술 후각막뒷면이미세하게뒤쪽으로전위하였다. 본연구의결과에서도 LASEK 수술후잠재성각막확장증의양상은보이지않았다. Beijing eye study에서중심각막이두꺼우면앞방깊이가 514

- 박진형외 : 라섹수술후전안부변화 - A B C D Figure 4. The schematic figures of change of the cornea after LASEK surgery. (A) Section of cornea during LASEK surgery.

Net force of free body diagram was directed posterior to anterior through axial plane. (D) Change of cornea and anterior chamber after LASEK surgery.

Because of tensile strength, the iris was displaced anteriorly resulting in the anterior chamber angle, volume, and depth was decreased. 얕고, 앞방각이좁다고하였다.

18 Tamburrelli et al 18 은굴절교정수술후콜라겐섬유소원배열이변하여조직의기계적세기가달라지고이는안구전체의강도와무관하게각막의강도와탄성에영향을주어안압이낮게측정될수있다고하였다.

6 - 박진형외 : 라섹수술후전안부변화 - A B C D Figure 4. The schematic figures of change of the cornea after LASEK surgery. (A) Section of cornea during LASEK surgery. (B) Magnification of section plane and free body diagram. (C) Magnification of section plane and net force of free body diagram. Net force of free body diagram was directed posterior to anterior through axial plane. (D) Change of cornea and anterior chamber after LASEK surgery. Posterior cornea was not displaced and the anterior cornea was displaced posteriorly. Because of tensile strength, the iris was displaced anteriorly resulting in the anterior chamber angle, volume, and depth was decreased. 얕고, 앞방각이좁다고하였다. 17 본연구에서 LASEK 수술후중심각막두께가얇아지며모든앞방척도들이감소하였는데, 이는정상안과굴절교정수술후상태는다른요인이관여하기때문일것으로보인다. 굴절교정수술후안압을골드만안압계로측정시실제보다낮게측정되며이는얇아진중심각막두께와관련이깊다고알려져있다. 18,19 각막기질의세포외기질이각막의물리학적특성을대부분결정하고이는각막콜라겐섬유소원의배열에따라달라진다. 18 Tamburrelli et al 18 은굴절교정수술후콜라겐섬유소원배열이변하여조직의기계적세기가달라지고이는안구전체의강도와무관하게각막의강도와탄성에영향을주어안압이낮게측정될수있다고하였다. Svedberg et al 19 은보우만층의결여와얇은각막두께가안압이낮게측정되는원인이며안압측정하강의정도는절제정도보다수술방법의차이가더욱큰영향을주어, PRK 나 LASEK보다 LASIK 수술에서안압이더욱낮게측정된다고하였다. 이는 LASIK 수술은 PRK나 LASEK과달리각막상피-보우만층복합체가유지되어각막창상치유과정에변화를주고각막의특성에영향을주기때문이라고하였다. Tsukiyama et al 20 은 orthokreatology 렌즈착용후각막의형태는변하지만앞방깊이는유의한변화를보이지않는다고하였다. Emre et al 21 은 Pentacam을이용한연구에서외안근절제와후전동시수술후중심각막두께는변화가없지만, 앞방깊이가얕아지고앞방부피가감소하는경향 이있다고하였다. 즉, 안구전체의강도및장력의변화는앞방깊이에영향을줄수있다고보여진다. 본연구에서술후각막후면은전위도는변화하지않고앞방깊이가얕아지고앞방각이좁아지며앞방부피가감소하는통계적으로유의한변화를보였는데, 이는 LASEK 수술후중심각막두께가얇아지게되면자유물체도에따라각막중심부에응력집중이발생하며안구자체의일정한압력에의해각막중심부에는바깥쪽방향의힘이증가하면서안구전체의축에따른장력이증가하게되지만각막자체의위치는이동하지않고홍채가앞쪽으로당겨지며앞방척도가변화하는것으로보여진다 (Fig. 4). Wong et al 22 은근시는녹내장의선행요인이라하였으며, LASEK 수술은굴절교정수술의발전과함께젊은연령에서흔하게시행되고있다. 본연구에서 LASEK 수술후앞방깊이가얕아지고앞방각이좁아지며앞방부피가감소하였는데, 근시환자가 LASEK 수술을시행받고, 추후녹내장검사를시행하게될경우앞방척도의변화도녹내장검사의고려사항이되어야할것이다. 결론적으로장기적인관찰이필요하겠지만 Pentacam을이용하여 LASEK 수술후 1개월째각막과앞방의변화를알아본결과, 각막앞면의비구면도와전위도가변하는반면, 각막뒷면의비구면도와전위도는변화하지않았다. 앞방척도는앞방깊이가얕아지고앞방각이좁아지며앞방부피가감소하였다. Pentacam은각막앞뒤면과함께앞방척도를비침습적으로손쉽게측정할수있는굴절교정수술 515

7 - 대한안과학회지 2009 년제 50 권제 4 호 - 전흔하게시행되는검사이므로, LASEK 수술과같은굴절교정수술전 Pentacam을이용하여측정한결과앞방각이좁고, 앞방깊이가얕은환자는앞방척도또한술전에고려하여야할것으로생각된다. 참고문헌 1) Kim ES, Jin KH. Evaluation of prophylactic use of mitomycin to inhibit haze formation after LASEK. J Korean Ophthalmol Soc 2007;48: ) Swartz T, Marten L, Wang M. Measuring the cornea: the latest developments in corneal topography. Curr Opin Ophthalmol 2007;18: ) Rabsiber TM, Khoramnia R, Auffarth GU. Anterior chamber measurement using Pentacam rotating Scheimpflug camera. J Cataract Refract Surg 2006;32: ) Nemeth G, Vajas A, Kolozsvari B, et al. Anterior chamber depth measurements in phakic and pseudophakic eyes: Pentacam versus ultrasound device. J Cataract Refract Surg 2006;32: ) Buehl W, Stojanac D, Sacu S, et al. Comparison of three methods of measuring corneal thickness and anterior chamber depth. Am J Ophthalmol 2006;141: ) Reuland MS, Reuland AJ, Nishi Y, Auffarth GU. Corneal radii and anterior chamber depth measurments using the IOLmaster versus the Pentacam. J Refract Surg 2007;23: ) Elbaz U, Barkana Y, Gerber Y, et al. Comparison of different techniques of anterior chamber depth and keratometric measurements. Am J Ophthalmol 2007;143: ) Shanker H, Taranath D, Santhirathelagan CT, Pesudovs K. Anterior segment biometry with the Pentacam: Comprehensive assessment of repeatability of automated measurements. J Cataract Refract Surg 2008;34: ) Chen D, Lam AK. Intrasession and intersession repeatability of the Pentacam system on posterior corneal assessement in the normal human eye. J Cataract Refract Surg 2007;33: ) Sanctis UD, Loiacono C, Richiardi L, et al. Sensitivity and specificity of posterior corneal elevation measured by Pentacam in discriminating keratoconus/subclinical keratoconus. Ophthalmology 2008;9: ) Ho JD, Tsai CY, Tsai RJ, et al. Validity of keratometric index: evaluation by the Pentacam rotating Scheimpflug camera. J Cataract Refract Surg 2008;34: ) Emre S, Doganay S, Yologlu S. Evaluation of anterior segment parameters in keratoconic eyes measured with the Pentacam system. J Cataract Refract Surg 2007;33: ) Anera RG, Jiménez JR, del Barci LJ, et al. Changes in corneal asphericity after laser in situe keratomileusis. J Cataract Refract Surg 2003;29: ) Ciolino JB, Khachikian SS, Cortese MJ, Belin MW. Long-term stability of the posterior cornea after laser in situ keratomileusis. J Cataract Refract Surg 2007;33: ) Hashemi H, Mehravaran S. Corneal changes after laser refractive surgery for myopia: comparison of Orbscan II and Pentacam findings. J Cataract Refract Surg 2007;33: ) Calossi A. Corneal asphericity and spherical aberration. J Refract Surg 2007;23: ) Xu L, Cao WF, Wang YX, et al. Anterior chamber depth and chamber angle and their associations with ocular and general parameters: the Beijing eye study. Am J Ophthalmol 2008;145: ) Tamburrelli C, Giudiceandrea A, Vaiano AS, et al. Underestimate of tonometric reading after photorefractive keratectomy increases at higher intraocular pressure levels. Invest Ophthalmol Vis Sci 2005;46: ) Svedberg H, Chen E, Hamberg-Nyström H. Changes in corneal thickness and curvature after different excimer laser photorefractive procedure and their impact on intraocular pressure measurements. Graefes Arch Clin Exp Ophthalmol 2005;243: ) Tsukiyama J, Miyamoto Y, Higaki S, et al. Changes in the anterior and posterior radii of the corneal curvature and anterior chamber depth by orthokeratology. Eye Contact Lens 2008;34: ) Emre S, Çankaya C, Demirel S, Doganay S. Comparison of preoperative and postoperative anterior segment measurements with Pentacam in horizontal muscle surgery. Eur J Ophthalmol 2008;18: ) Wong TY, Klein BE, Klein R, et al. Refractive errors, intraocular pressure, and glaucoma in a white population. Ophthalmology 2003;110:

8 - 박진형외 : 라섹수술후전안부변화 - =ABSTRACT= Changes in the Cornea and Anterior Chamber After LASEK: Pentacam Findings Jin-Hyoung Park, MD 1, Ja-Hun Kang, MD, PhD 2, Kyung-Hyun Jin, MD, PhD 1 Department of Ophthalmology, KyungHee University Medical Center 1, Seoul, Korea Department of Ophthalmology, KyungHee University East-west Neo Medical Center 2, Seoul, Korea Purpose: We evaluated changes in the cornea and anterior chamber after LASEK using Pentacam to search for signs of subclinical keratectasia occurrence. Methods: Seventy-one eyes of 36 patients who had received LASEK were enrolled in this study. All eyes were examined for asphericity of the anterior and posterior cornea (Q-value), anterior and posterior corneal displacement, central corneal thickness, anterior chamber depth, angle, and volume using Pentacam before surgery and again one month after the operation. Results: The postoperative changes in the asphericity of the posterior cornea and posterior corneal displacement were not statistically significant(p=0.668, p=0.101). The anterior chamber depth, angle, and volume decreased by mm, 0.983, 7.21 mm 3 after LASEK, respectively. (p=0.000) The postoperative changes in asphericity of the anterior cornea, anterior corneal displacement, and central corneal thickness were statistically significant(p=0.000). Conclusions: In this study, we compared changes in the anterior chamber and cornea after LASEK using Pentacam. Changes in the anterior cornea were significant; however, the posterior cornea did not change significantly. The anterior chamber depth, anterior chamber angle, and volume were decreased one month after the operation, although further long-term follow-ups will be necessary to verify these findings. J Korean Ophthalmol Soc 2009;50(4): Key Words: Anterior chamber, Cornea, LASEK, Pentacam Address reprint requests to Kyung-Hyun Jin, MD, PhD Department of Ophthalmology, KyungHee University Hospital #1 Hoegi-dong, Dongdaemun-gu, Seoul , Korea Tel: , Fax: , khjinmd@khmc.or.kr 517

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