= 증례보고 = 대한안과학회지 213 년제 54 권제 6 호 J Korean Ophthalmol Soc 213;54(6):877-886 pissn: 378-6471 eissn: 292-9374 http://dx.doi.org/1.3341/jkos.213.54.6.877 전안부빛간섭단층촬영기를이용한백내장절개창의크기에따른창상치유과정의형태학적관찰 김진형 김태임 김응권 이형근 연세대학교의과대학안과학교실, 시기능개발연구소 목적 : 백내장수술후절개부위를전안부빛간섭단층촬영기로촬영하여시간에따른창상치유과정의변화를관찰하였다. 대상과방법 : 백내장수술을시행받은총 34 명 (44 안 ) 을절개범위에따라 1 군 (2.2 mm) 과 2 군 (2.8 mm) 으로분류하고절개부위를술후 1 일, 1 주일, 1 개월째빛간섭단층촬영기로기록하여, 시간에따른절개각도, 절개길이, 각막상피 / 내피결손길이, 각막상피 / 내피결손면적, 절개부위의최대각막두께등을측정하고데스메막박리의유무를비교하였다. 결과 : 수술후 1 개월까지각막내피결손길이, 각막내피결손면적은 1 군에서 2 군보다더높은경향을보였고, 술후 3 일째차이는통계학적으로유의미하였다 (p=.15,.27). 두절개군간절개각도, 절개길이, 절개부위최대각막두께는통계학적유의한차이는없었고, 데스메막박리는절개창크기에따른발생비율의차이는없었으나, 연령이높고수술후안압이낮을수록발생이증가하였다 (p.5). 결론 : 두절개군모두우수한창상치유과정을보였으며, 데스메막박리를줄이기위해선고령의환자일수록술중절개부위조작과술후안압조절에더유의해야할것으로생각한다. < 대한안과학회지 213;54(6):877-886> 초음파유화술의도입과수술기법, 인공수정체의발달로점점작은절개창에의한백내장수술이가능해지게되었고, 이러한작은절개창기법은술후상처부위의빠른회복과술중발생할수있는각막난시를최소화할수있다는장점이있어시력의질을높이고자하는시도의일환으로널리선호되고있다. 1-4 기존의 2.8 mm 절개창백내장수술에이어 2.2 mm 기법이많이사용되고있고, 절개창크기가점점감소하여현재는 1.5 mm 이하의크기를통한 bimanual technique까지소개되어실제임상에적용되고있는실정이다. 하지만관류와흡입을분리시키는이기법은관류량, 흡입속도의제한으로수술시간이길어지고, 술중전방유지의불안정과함께기존의인공수정체삽입을위해선추가절개창연장이필요하다는단점이있으며, 1.5 mm 이하절개창에맞게고안된인공수정체삽입시에도단면 (singe plane) 을이용한절개창에의해술후지속적인누출과치명적인안내염발생의원인이될수있다. 한편 1992 Received: 212. 6. 22. Revised: 213. 1. 3. Accepted: 213. 4. 15. Address reprint requests to Hyung Keun Lee, MD Department of Ophthalmology, Gangnam Severance Hospital, #211 Eonju-ro, Gangnam-gu, Seoul 135-72, Korea Tel: 82-2-219-344, Fax: 82-2-3463-149 E-mail: shadik@yuhs.ac * 이논문의요지는 211 년대한안과학회제 16 회학술대회에서구연으로발표되었음. 년 Fine A 에의해소개된무봉합투명각막절개술 (sutureless self-healing clear corneal incisions : CCIs) 은절개창크기감소로가능해진기법으로수술시간의단축, 봉합에의한난시유발감소, 빠른창상회복이가능하다는장점이있지만, 술후절개창을통한창상유출과안내염발생을증가시킨다는결과가여러논문에의해보고된바있다. 5-11 무봉합, 작은크기의각막절개술로요약되는최근백내장수술기법이여러장점이있음에도불구하고, 안내염등중대한합병증발생과의관련성이있는것으로알려졌으며, 최근전안부빛간섭단층촬영의도입으로쉽고빠르게실제창상부위를고해상도영상으로분석하는것이가능해지게되었다. 시간에따른상처부위의형태학적변화와술후합병증발생과의관련성을알아보고이를임상에적용함으로써보다안전하고빠른창상회복에중요한역할을할것으로생각한다. 따라서이에본연구에서는최근가장많이사용되는 2.2 mm 동축소절개백내장수술군 (Microcoaxial cataract surgery: MCCS) 과기존의 2.8 mm 백내장수술군 (conventional cataract surgery: CCS) 으로나누어, 술후 1일, 7일, 3일째절개부위를전안부빛간섭단층촬영기를통해촬영하고두절개군간의절개각도, 절개길이, 절개부위최대각막두께, 각막상피 / 내피결손길이및면적, 데스메막박리유무등을관찰하여시간에따른창상치유과정을비교해보고자하였다. www.ophthalmology.org 877
- 대한안과학회지 213 년제 54 권제 6 호 - 대상과방법 211년 5월부터 1월까지본원안과에서노년성 (senile cataract) 혹은노년기전백내장 (presenile cataract) 으로합병증이없는백내장적출술및뒤방인공수정체삽입술을시행한총 34명, 44안을대상으로하여전향적인연구를시행하였다. 모든환자들에게설명에근거한동의를받았으며, 이전에안과적수술이나외상을받았거나백내장이외에안과적질환을가진사람은본연구에서제외하였다. 술전시력검사, 안압검사, 굴절검사, 세극등검사, 안저검사를시행하였고각막내피세포수및 LOCS (Lens Opacities Classification System) III 분류에의한백내장진행정도를평가하였다. 절개창범위에따라 1군 (11명, 14안 ) 에서는 2.2 mm 소절개투명각막절개하에술후각막봉합은하지않고자연치유되도록하였고, 2군 (23명, 3안 ) 에서는기존의 2.8 mm 투명각막절개를시행하고, #1- Nylon 을이용하여한바늘의봉합시행후수술후 2주째봉합사제거를하였다. 수술은 Alcaine을이용한점안마취및 lidocaine에의한테논낭하마취후시행되었고초음파수술기구 (Infiniti Vision System R, Alcon Laboratories, Inc., Fort Worth USA) 를이용하여초음파유화술을시행한후인공수정체를삽입하였으며, 수술후각막절개부위를평형염액 (balanced salt solution, BSS R, Alcon, USA) 을이용하여기질수화 (stromal hydration) 를시행하였다. 술후에는 Levofloxacin eyedrop (Cravit R ) 과 Prednisolone acetate eyedrop (Pred Forte R ) 을 6시간간격으로점안하고, 술후관찰하면서전방염증정도에따라서서서히용량을감소시켰다. 백내장수술을시행받은모든환자들에게세극등현미경, 시력, 안압, 굴절검사등의기본안과검사와함께전안부 OCT (Cirrus OCT, Carl Zeiss Meditec, Germany) 를이용하여절개창부위를고해상도영상으로술후 1일, 1주일, 1개월째촬영하였다. 검사시환자로하여금기계안쪽의지표를주시하게한후절개부위를수평축, 수직축을기준으로전안부 5-Line Raster 모드로촬영하였으며, 검사및측정 (measurement) 모두동일한술자가시행하였다. 한사람당 3회씩반복촬영하여, 그중해상도가우수하고결손면적이가장큰이미지를선택하였고, 두명의관찰자에의해중복으로검토되었다. 선택된영상은 Image J (NIH, Bethesda, Maryland) 프로그램을이용하여, 절개각도 (incision angle), 절개길이 (incision length), 각막상피 / 내피결손길이 (epithelial/endothelial gap length), 각막상피 / 내피결손면적 (epithelial/endothelial gap area), 절개부위의최대각막두께 (maximal corneal thickness at incision site) 를측정하고데스메막박리 (Descemet s membrane Figure 1. Anterior segment OCT (optical coherence tomography) image showing a clear corneal incision site postoperatively. The definition of incision site parameters: 1) Incision angle (The angle between the line that joins the epithelial and endothelial ends of the incision and the tangential line on the corneal surface) 2) Incision length (The total length of the main incision measured from the wound entry to its exit point) 3) Epithelial/endothelial gap length (The length that lines inside of the gap, the longer one is selected, if present) 4) Epithelial/ endothelial gap area (The area inside of the gap, if present) 5) Descemet s membrane detachment 6) Maximal corneal thickness at the incision site. detachment) 의유무를기록하였다. 6개의측정치에대한설명은다음과같다 (Fig. 1). 1) 절개각도 (incision angle): 각막상피의외측절개선입구와각막내피내측절개선출구를연결하는선과각막상피외측절개선입구의경계면에대한접선이이루는각도 2) 절개길이 (incision length): 각막상피외측절개선입구부터각막내피내측절개선출구까지실제절개선의총길이 3) 각막상피 / 내피결손길이 (epithelial/endothelial gap length): 각막상피또는각막내피결손이존재할경우, 결손부위를구성하는내측길이 4) 각막상피 / 내피결손면적 (epithelial/endothelial gap area): 각막상피또는각막내피결손이존재할경우, 결손부위를구성하는내측총면적 5) 데스메막박리 (Descemet s membrane detachment): 각막기질과데스메막간의분리 6) 절개부위의최대각막두께 (maximal corneal thickness at incision site): 각막내측절개선부위각막두께의최대치수술전후의측정치비교는 independent samples t-test, chi-square test를이용하여비교하였고, 모든통계분석은 SPSS (version 18., software for Windows; SPSS Inc., Chicago, IL, USA) 를이용하였으며, p-value<.5를통 878 www.ophthalmology.org
- 김진형외 : 술후백내장절개창의형태학적관찰 - 계적으로의미있다고취급하였다. 결과 전체 44안에서 2.2 mm (1군) 절개를시행받은군은남자 5안, 여자 9안으로총 14안이었고 2.8 mm (2군) 절개군은남자 14안, 여자 16안으로총 3안이었다. 환자의평균연령은 1군에서 66.1 ± 8.2세, 2군은 66.4 ± 6.8세로두군간의통계학적차이는없었으며, 술전교정시력, 안압, 난 시, 각막내피세포수, LOCS (Lens Opacities Classification System) III 분류에의한핵경화도에서도통계학적유의한차이는보이지않았다 (Table 1). 연구기간동안본원에서백내장수술을시행한모든경우에서전낭확장및후낭파열, 유리체소실등의술중합병증은발생하지않았고, 안내염, 창상유출을포함한중대한술후합병증역시발생하지않았다. 평균초음파사용시간 (mean phacoemulsification time), 평균수술시간 (mean operation time), 사용된총 BSS 양등, 술중지표에서도두군간통계학적차이는없었다 (Table 2). Table 1. Preoperative patient characteristics Group 1 (2.2 mm) Group 2 (2.8 mm) p-value Eyes (n) 14 3 Sex (Male/Female) 7/7 1/2.29 Laterality (OD/OS) 5/9 14/16.495 Mean age (year) 66.1 ± 8.2 66.4 ± 6.8.58 * Mean CDVA (Snellen).32 ± 2.22.48 ±.24.111 * Mean IOP (mm Hg) 9.57 ± 2.65 11.76 ± 3.3.187 * Mean astigmatism (D) 1.56 ± 1.23 1.42 ±.74.649 * Endothelial cell count 2752.5 ± 4.5 2792.4 ± 347.3.894 * Cataract hardness (LOCS III) Cortical density 3.7 ± 1.49 2.84 ± 1.65.66 * Nucleus density 3.42 ± 1.55 2.83 ±.97.199 * Posterior subcapsular opacity 2.53 ± 1.97 1.34 ± 1.11.49 * Values are presented as mean ± SD. CDVA = corrected distance visual acuity; IOP = intraocular pressure; LOCS = Lens Opacities Classification System. * Independent samples t-test; Chi-square test. Table 2. Comparison of mean surgical parameters between 2.2-mm and 2.8-mm incision group Group 1 (2.2 mm) Group 2 (2.8 mm) p-value * Mean phaco time (sec) 21.14 ± 8.45 21.9 ± 13.91.891 Mean operation time (min) 29.78 ± 4.28 27. ± 4.97.78 Mean fluid used (ml) 13.57 ± 29.34 19.64 ± 34.27.385 Values are presented as mean ± SD. Independent samples t-test. Table 3. Postoperative changes in mean UCVA and IOP and astigmatism by autorefractor Group 1 (2.2 mm) Group 2 (2.8 mm) p-value * Mean UCVA (Snellen) 1 day.62 ±.15.68 ±.26.29 7 days.69 ±.23.73 ±.23.62 3 days.72 ±.23.71 ±.21.836 Mean IOP (mm Hg) 1 day 9.92 ± 2.99 11.25 ± 3.65.235 7 days 9.3 ± 2.83 1.44 ± 3.22.293 3 days 9. ± 2.52 1.8 ± 2.83.9 Mean astigmatism (D) 1 day 1.7 ±.47 1.16 ±.85.767 7 days 1.5 ±.45 1.27 ±.89.459 3 days.75 ±.78 1.4 ±.58.219 Values are presented as mean ± SD. UCVA = uncorrected visual acuity; IOP = intraocular pressure; D = diopter. * Independent samples t-test. www.ophthalmology.org 879
- 대한안과학회지 213 년제 54 권제 6 호 - Table 4. Results of AS-OCT parameters Parameter All Patients Group 1 (2.2 mm) Group 2 (2.8 mm) p-value Mean angle ( ) 1 day 45.29 ± 7. 39.75 ± 7.6 47. ± 6..98 * 7 days 42.5 ± 5. 38.62 ± 5.5 45.8 ± 2.4.112 * 3 days 4.22 ± 6.3 38.28 ± 5.5 47. ± 1.4.82 * Mean length (μm) 1 day 1494.1 ± 295.1 163. ± 319.4 146.6 ± 285.3.239 * 7 days 1468.8 ± 243.1 1514.5 ± 258.9 1444.5 ± 239.8.524 * 3 days 1288.4 ± 212.9 1317. ± 216.6 1231.2 ± 216.6.483 * Mean maximal CT at incision site (μm) 1 day 128.1 ± 7.5 984. ± 95.7 135.4 ± 64.5.133 * 7 days 998.3 ± 13. 964.6 ± 138.6 18.4 ± 91.9.373 * 3 days 753.3 ± 76.5 769.7 ± 85.5 73.4 ± 63..46 * Mean endothelial gap length (μm) 1 day 21. ± 14. 254. ± 111.4 184.7 ± 98.1.1 * 7 days 162.6 ± 9.8 197. ± 12.2 144.2 ± 81.8.191 * 3 days 63.4 ± 55.7 86.8 ± 48.9 16.8 ± 37.5.15 * Mean endothelial gap area (μm 2 ) 1 day 2614.4 ± 1741.1 356. ± 1937.5 2323.5 ± 165.1.79 * 7 days 1981.3 ± 1224.7 24.5 ± 1166.2 1757.8 ± 1234.1.239 * 3 days 58.5 ± 737.5 737.6 ± 815.9 5.4 ± 112.6.27 * DM detachment (%) 1 day 79.4 75. 8.7.89 7 days 39.1 37.5 4..785 3 days - Values are presented as mean ± SD. Independent samples t-test; Chi-square test. 술후시간에따른나안시력, 안압, 잔여난시량변화를비교해보면 1일, 7일, 3일째양군간통계학적으로유의한시력차이는보이지않았고, 안압및난시의경우, 1군이 2군보다낮은경향을나타냈지만통계적으로의미있는차이는아니었다 (Table 3). 전안부빛간섭단층촬영기를이용한수술후절개부위지표의변화는다음과같다 (Table 4, Fig. 2). 먼저, 평균절개각도를보면, 2.2 mm 군은술후 1일, 1 주일, 1개월째 39.75 ± 7.6, 38.62 ± 5.5, 38.28 ± 5.5, 2.8 mm 군은 47. ± 6., 45.8 ± 2.4, 47. ± 1.4 로두절개군간통계학적유의한차이는보이지않았다 (p=.98,.112,.82). 평균절개길이를측정했을때, 2.2 mm 군에서 163. ± 319.4 μm, 1514.5 ± 258.9 μm, 1317. ± 216.6 μm이고 2.8 mm 군에서 146.6 ± 285.3 μm, 1444.5 ± 239.8 μm, 1231.2 ± 216.6 μm로두군모두술후 1개월까지감소하는경향을보였지만, 수치상통계학적으로의미있는차이는아니었다 (p=.239,.524,.483). 한편, 술후 1개월까지절개부위의최대각막두께의변화를비교했을때, 2.2 mm 군에서 984. ± 95.7 μm, 964.6 ± 138.6 μm, 769.7 ± 85.5 μm, 2.8 mm 군에서 135.4 ± 64.5 μm, 18.4 ± 91.9 μm, 73.4 ± 63. μm 로시간에따라두절개군모두절개부위두께가감소하였 지만, 의미있는차이는아니었다 (p=.45,.32,.695). 본연구에포함된백내장수술을시행받은모든환자군에서각막상피결손은발견되지않았고, 반면각막내피결손은모든환자군에서관찰되었다. 술후 1일, 1주일, 1개월째각막내피결손길이를비교하면, 2.2 mm 군에서 254. ± 111.4 μm, 197. ± 12.2 μm, 86.8 ± 48.9 μm, 2.8 mm 군은 184.7 ± 98.1 μm, 144.2 ± 81.8 μm, 16.8 ± 37.5 μm이고, 각막내피결손면적의경우, 2.2 mm 군에서 356. ± 1937.5 μm 2, 24.5 ± 1166.2 μm 2, 737.6 ± 815.9 μm 2, 2.8 mm 군에서 2323.5 ± 165.1 μm 2, 1757.8 ± 1234.1 μm 2, 5.4 ± 112.6 μm 2 이었다. 각막내피결손길이, 각막내피결손면적의경우, 술후 1개월까지 2군 (2.8 mm) 이 1군 (2.2 mm) 보다더낮은수치를보였고, 술후 1개월째두절개군간내피결손길이, 내피결손면적의차이는통계학적으로유의미한것이었다 (p=.15,.27). 데스메막박리의경우 2.2 mm 와 2.8 mm 군에서, 술후 1일째 75.%, 8.7% 의비율로발생하였고, 1주일째 37.5%, 4.% 에서관찰되었으며, 술후 1개월째에는모든환자에서소실되었다. 술후 1일째데스메박박리발생군이발생하지않은군에비해평균연령 67.8 ± 6.5세로 59.8 ± 7.8세에비해더높았고, 수술후 1일째평균안압은 1.4 ± 3.6 mmhg 로데스메막박리가없 88 www.ophthalmology.org
- 김진형외 : 술후백내장절개창의형태학적관찰 - A 5 Group 1 (2.2 mm) Group 2 (2.8 mm) B 18 16 Group 1 (2.2 mm) Group 2 (2.8 mm) 4 14 Mean angle ( ) 3 2 Mean length ( m) µ 12 1 8 6 1 4 POD 1 day POD 7 days POD 3 days 2 POD 1 day POD 1 day POD 7 days POD 3 days C 12 Group 1 (2.2 mm) Group 2 (2.8 mm) D 3 Group 1 (2.2 mm) Group 2 (2.8 mm) Mean corneal thickness ( m) µ 1 8 6 4 2 Mean endothelial gap length ( m) µ 25 2 15 1 5 * * POD 1 day POD 7 days POD 3 days POD 1 day POD 7 days POD 3 days E Mean endothelial gap area ( m ) µ 2 4 35 3 25 2 15 1 5 Group 1 (2.2 mm) Group 2 (2.8 mm) POD 1 day POD 7 days POD 3 days Figure 2. Results of AS-OCT parameter, (A) Mean angle ( ); (B) Mean length (μm); (C) Mean corneal thickness at incision site (μm); (D) Mean endothelial gap length (μm); (E) Mean endothelial gap area (μm 2 ) ( * p <.5). 는군의안압 14.2 ± 2.4 mmhg 에비해더낮았으며, 앞의두항목모두통계학적으로유의미한차이였다 (p=.46,.25). 술후 7일째까지데스메막박리가남아있는군과그렇지않은군을비교해보면, 박리가남아있는군이그렇지않은군에비해평균연령 7.8 ± 4.8세로 62. ± 6.3세보다연령이더높고, 술후안압에서 8.1 ± 3.4 mmhg 로박리소견이없는군의안압인 1.9 ± 2.1 mmhg 에비해더낮았으며, 두절개군간연령, 술후안압역시통계적으로의미있는차이였다 (p=.2,.33) (Table 6). 한편연령대에따른데스메막박리의발생비율을살펴보면, 5대 의경우, 수술후 1일째 4% 에서발생하였고, 술후 7일이후부터관찰되지않은반면, 6대에서는술후 1일째, 85.7% 에서발생하고, 술후 7일째에는 46.1% 로감소하였으며, 술후 3일째에는발견되지않았다. 7대이상의연령대에서는술후 7일째까지모든환자군에서데스메막박리소견이관찰되었으나, 술후 3일째에는모두소실되었으며, 이중연령별에따른술후 1일째데스메막박리발생비율의차이는통계학적으로유의미한것이었다 (p=.35) (Table 5, Fig. 3). www.ophthalmology.org 881
- 대한안과학회지 213 년제 54 권제 6 호 - Table 5. The ratio of postoperative Descemet s membrane detachment by age 5-59 (years) 6-69 (years) 7-79 (years) 8-89 (years) p-value * DM detachment (%) 1 day 4 85.7 1 1.35 7 days 46.2 1 1.337 3 days - DM = Descemet s membrane. Chi-square test. Table 6. Parameters of groups with and without Descemet s membrane detachment Non-DMD DMD p-value * Mean age (year) 1 day 59.8 ± 7.75 67.8 ± 6.49.25 7 days 62. ± 6.29 7.77 ± 4.81.2 Mean UCVA (Snellen) 1 day.48 ±.29.52 ±.22.713 7 days.76 ±.26.75 ±.22.919 Mean IOP (mm Hg) 1 day 14.2 ± 2.38 1.42 ± 3.64.39 7 days 1.85 ± 2.7 8.13 ± 3.39.33 Endothelial cell count 1 day 2631.8 ± 146.4 2881.5 ± 354.7.141 7 days 2798.7 ± 42.7 2766. ± 53.9.87 Mean phaco time (sec) 1 day 28.14 ± 2.81 21.35 ± 15.35.7 7 days 21.25 ± 14.71 15.68 ± 11.11.427 Mean operation time (min) 1 day 25. ± 2.34 26.85 ± 5.52.474 7 days 29.3 ± 4.47 3.33 ± 2.91.554 Mean corneal thickness (μm) 1 day 152. ± 33.7 1285.9 ± 25.1.1 7 days 1117.5 ± 181.3 1288.8 ± 214..56 Values are presented as mean ± SD. DMD = Descemet s membrane detachment; UCVA = uncorrected visual acuity; IOP = intraocular pressure. * Independent samples t-test. 1 고 찰 Patients (%) 9 8 7 6 5 4 3 2 1 5-59 6-69 7-79 8-89 Age (years) Pod#1 day Pod#7 days Pod#3 days Figure 3. The ratio of postoperative Descemet s membrane detachment by age ( * p <.5). 투명각막절개법은현재백내장에서가장널리시행되고있는기법으로, Kelman 1 에의해초음파유화술이도입된이후각막난시변화, 상처관련합병증, 술후안내염증등을감소시킬목적으로절개창의크기를줄이는방향으로발전되어왔다. 절개창길이가짧아지면서무봉합의창상치유가가능해지고, 빠른상처회복을기대할수있으나, 안내염발생등술후중대한합병증이동반될수있다는결과가보고된바있다. 최근전안부빛간섭단층촬영 (anterior segment OCT) 의도입으로술후절개부위를비접촉성 (non-contact), 비침습적 (non-invasive method) 으로쉽고빠르게고해상도영상의구현이가능해졌다. 본연구에서사용된 Cirrus OCT는 84 nm의파장을이용하여후안부영상을촬영하 882 www.ophthalmology.org
- 김진형외 : 술후백내장절개창의형태학적관찰 - 는장치로개발되었으나, anterior segment mode 소프트웨어가도입되면서전방각, 각막에대한전안부평가가가능해졌다. 전안부촬영 mode 중하나인 5-Line Raster는 25 μm 간격으로서로떨어진 3 mm 길이의평행한 5개의선을기준으로촬영하고자하는전안부부위를 3-5 μm의 axial resolution으로초고해상도이미지를촬영하게된다. 현재전안부평가에널리사용되고있는 Visante OCT (Carl Zeiss Meditec, Germany) 가 18 μm의 axial resolution과 6 μm의 transverse resolution을가지고 131 nm 파장의적외선을이용하여촬영한높은선명도의영상을가지고안구의전안부병리및형태학적연구에유용한장점이있는반면, Visante OCT 빛의파장으로모양체고랑같은홍채뒤쪽구조및공막돌기위치를촬영하기어렵다는단점이있다. 최근도입된 Cirrus OCT 전안부 mode 로공막돌기, 섬유주, 쉬발베선등의전방각구조뿐아니라, 각막의구조적특징및병리적이상상태를빠르게촬영하고, 더우수한 resolution의초고해상도영상을얻을수있다는장점이있다. 이를이용한백내장수술절개부위와관련된형태학적변화의파악이술후합병증예방과창상관리에있어중요한역할을할것으로기대된다. 한편 1.5 mm 이하의획기적으로작은절개창기법이시도되고있지만, 관류와흡입의제한으로인해유발되는수술시간의연장, 술중전방유지의불안정성, 인공수정체삽입시절개창의연장등은오히려각막절개부위의손상을가중시켜상처관련합병증을증가시킬가능성이있다. 기존의 2.8 mm 절개창의백내장기법과마찬가지로관류와흡입이하나의축 (coaxial phacoemulsification) 으로진행되는 2.2 mm 절개창수술은안정적이고보다작은절개창의장점을갖추고있어, 현재가장널리사용되고있는두기법에대해절개창크기에따른술후절개부위의형태학적변화에대해구체적으로비교해보고자본연구를시행하게되었다. 12 백내장수술후전안부빛간섭단층촬영기를이용한절개창의변화에대한논문은많이발표되었지만, 술후단기경과관찰인경우가많고, 형태학적분석에초점이맞춰져있으며, 이와관련된국내연구는전무한상태이다. 13-18 본논문은술후절개부위를촬영한고해상도이미지를통해절개각도, 절개길이, 절개부위각막두께를비롯하여, 실제상처회복의지표로활용될수있는실제각막의결손길이, 결손면적등을 Image J (NIH, Bethesda, Maryland) 프로그램을이용하여수치화함으로써시간에따른창상치유과정을정량화시켰다는데그의의가있다고하겠다. 본연구의결과 2.2 mm, 2.8 mm 절개군모두창상유출 (wound leak), 창상파열 (wound rupture), 상피눈속증식 (epithelial downgrowth), 감염성안내염 (endophthalmitis) 등중대한합병증은발생하지않았다. 두그룹간시간에따른절개각도, 절개길이, 절개부위각막두께, 데스메막박리비율은통계학적유의한차이는없었다. 한편두절개군모두절개부위결손의뛰어난회복을보여주었는데, 내피결손길이, 내피결손면적의항목에서 2.2 mm 절개군이 2.8 mm 절개군보다높은수치경향을나타냈고술후 3일째차이만이통계적으로의미가있었다 (p=.15,.27). 데스메막박리비율은절개크기와관련이없었으며, 연령이높고, 술후안압이낮은환자일수록그발생비율이증가하였다. 수술후시력, 안압에있어두절개군간통계학적차이는없었으며, 잔여난시량의경우술후 1달까지 2.2 mm 군이 2.8 mm 군보다낮은경향을보였지만, 유의한차이는없었다. 본연구에선 2.8 mm 환자군에서술후창상유출및안내염발생을줄일목적으로 monofilament nylon 봉합을시행하고, 창상압박에의한난시발생을감소시키기위해술후 2주째봉합발사를시행한반면, 2.2 mm 군에서는무봉합자연치유과정을거쳤는데, 이러한점에의해단순절개창크기에따른잔여난시량의비교는한계가있었으며, 절개창크기가작을수록술후유발되는각막난시가작다는것은여러연구에서밝혀진바있지만, 본연구에서통계적으로유의한차이를보이지않은것은이러한원인에의한것으로보인다. 본저자는절개부위가작아질수록백내장수술중절개부위의첨단부 (phaco tip) 조작으로인해각막절개부위에대한열, 기계손상의위험성이증가함에따라각막내피손상의가능성이높아질것으로예상하였다. 실제전안부빛간섭단층촬영기를통해측정한시간에따른평균각막내피결손길이및면적을비교해보면, 술후 3일까지두항목모두 2.2 mm 절개군이 2.8 mm 군보다높은수치를나타냈다. 술후 3일째잔여내피결손길이, 잔여내피결손면적을보면 2.8 mm 절개군에서 16.8 ± 37.5 μm, 5.4 ± 112.6 μm 2 로술후 1일째수치에대비하여그비율이 9.9%, 2.16% 남아있는데반해 2.2 mm 절개군에서는 86.8 ± 48.9 μm, 737.6 ± 815.9 μm 2 로남아있는결손비율이 34.17%, 2.71% 로 2군 (2.8 mm) 보다높은비율이었다. 따라서술후 1달째창상부위의잔여결손비율은 2.8 mm 군보다 2.2 mm 군에서더컸으며, 이러한수치의차이는통계학적으로의미가있는것이었다 (p=.15,.27). 이러한결과는술후회복과정에있어소절개군에서는무봉합, 기존절개군에선봉합후발사라는방식의차이가있었던점을고려할때창상치유과정에있어절개범위크기자체보다창상부위가장자리를서로당겨주는봉합효과의창상에대한안정성을시사한다고생각해볼수있다. 하지만 www.ophthalmology.org 883
- 대한안과학회지 213 년제 54 권제 6 호 - 이와반대로봉합실이유발하는염증으로인한상처치유지연가능성또한배제할수없고, 앞으로절개창크기, 절개창단면모양, 술중조작등의요인을통제하여봉합이창상회복에미치는영향과관련된연구가필요할것으로생각한다. 본연구에서 LOCS (Lens Opacities Classification System) III 분류에의한백내장정도를살펴보면, 피질혼탁및핵경화는두절개군간유의한차이가없었으나, 후낭하혼탁이통계적유의한차이로 2.2 m 절개군에서더심하였다. 이처럼수정체경화도와두께가증가함에따라, 총수술시간, 초음파사용시간, 강도의증가및초음파기구의각막내피와의접촉기회가증가함에따라, 열, 기포발생등으로인한각막내피손상이증가할수있다는점을감안할때, 본연구에서실제평균초음파유화흡인술시간및평균수술시간에서두군간의통계학적유의한차이는없었으나, 술중내피손상에영향을줄수있는원인으로후낭하혼탁의차이를생각해볼수있으며, 이는본연구의한계점이라할수있다. 본연구의또다른한계점으로백내장절개창평가에있어동일검사자가전안부 OCT를이용하여절개창부위를 3회반복시행하여얻은영상중최대결손면적의이미지를기준으로평가하였는데, 이는 2차원적단면적, 길이를측정한것으로실제술후발생하는 3차원적절개창의부피, 면적을온전히반영하지못한다는한계점이있다. 하지만본저자는최대결손단면적이실제결손량과양의상관성을보인다는가정하에이를상처치유과정의지표로삼고연구를진행하게되었다. 한편예전논문에서발표된데이터를살펴보면, 술후 1일째절개부위각막상피폐쇄율은 1% 에달하였다. 14,19-22 본연구에서도각막상피결손은발견되지않았지만, 이에반해각막내피결손은대부분의경우에서관찰되었다. McGowan 23 은술후창상회복과정에서각막내피세포가펌프기능을통해각막기질쪽으로물을빨아들이거나 (suction) 내보내는힘에저항하는각막수화 (corneal hydration) 기능으로써각막기질수분의양을일정하게유지하려한다고하였다. 이러한내피세포의흡인작용 (suction) 의방향이각막내피세포결손폐쇄에는도움이되지만, 각막상피결손이발생한경우, 창상가장자리회복에반대되는힘으로작용해안내염발생을높일수있다고하였으며, 술후초기전안부빛간섭단층촬영의도움으로각막상피결손여부를확인하는것이창상유출, 감염성안내염등합병증예방에중요한역할을할것으로생각한다. 한편술중에시행되는기질수화 (stromal hydration) 는술후내피세포기능저하에의한흡인력을보상함으로써, 실제각막내피결손발생비율을감소 시킨다는보고가있었는데, 본연구의두절개창군모두기질수화를시행하여, 기질수화가내피결손길이, 내피결손크기에미치는영향은확인하지못하였다. 15,21,24 Calladine and Tanner 21 은기질수화를시행한군과시행하지않은군에서데스메막박리비율이 63%, 25% 로차이가있다고하였는데, 이는기질수화시각막기질층의팽창하려는힘과부종없이본구조를유지하려는데스메막의물리적특성의차이에의한것이며, 술후안압이높을수록발생비율이감소하는데그원인으로안압에의해박리된데스메막이노출된각막표면으로압박되기때문이라고하였다. 25 이는술후 1일째데스메막박리박리없는환자군의안압이박리가관찰된환자군보다통계적으로유의하게높게나타난본연구의결과와일치하는것이다. Xia et al 26 은 3.2 mm 투명각막절개시행후술후 1일째전안부단층촬영결과데스메막박리비율이 82% 이며, 술전낮은안압과관련성이있고, 그외연령, 술후안압, 각막내피세포, 각막두께등과는관련이없다고하였다. 본연구에서시행된술후 1일째데스메막박리비율은 2.2 mm 군에서 75.%, 2.8 mm 군에서 8.7% 로 Xia et al 26 의수치와비슷하였고, 술후 1, 7일째데스메막박리는술후낮은안압과유의한관계가있었다. 본결과에따르면, 술후낮은안압이데스메막박리와관련성이있었고, 연령이높은환자일수록그발생비율이높고, 오래지속되는경향을나타냈는데연령에따른데스메막박리관련성은통계학적으로술후 1일째에만유의미하였다 (p=.35). Can et al 24 은술후안압이높을수록데스메막박리비율과각막내피결손비율이감소한다고하였는데, 본연구결과에따르면술후안압과각막내피결손의길이, 면적과의유의한관련성은없었지만데스메막박리의비율을감소시킨다는점을볼때, 술후안압이구조적창상치유과정에영향을미침을알수있었다. 본연구에서백내장수술후절개창의변화를전안부빛간섭단층촬영을통해관찰한결과, 2.2 mm, 2.8 mm 절개군모두중대한합병증발생없이우수한창상치유과정을보여주었다. 본논문에서소개된절개창부위의결손길이, 결손면적, 데스메막박리항목은앞으로백내장술후창상치유과정의기준지표로활용되어합병증예방과창상부위안정화에기여할것으로기대된다. 본연구에서관찰되지는않았지만, 창상유출과관련성이높은각막상피결손이관찰될경우, 술후창상관리에각별히유의해야하며, 술후정기적으로실제각막결손의길이, 면적을관찰, 측정함으로써창상회복정도를파악할수있을것으로생각한다. 본연구를통해데스메막박리의경우, 절개범위와관계없이연령, 술후안압과밀접한관련이있음을알수있었고, 데스메 884 www.ophthalmology.org
- 김진형외 : 술후백내장절개창의형태학적관찰 - 막박리의소실이창상부위의해부학적회복을시사한다고볼때, 6대이상고령군및술후안압이 1 mmhg 이하의환자군에서술후창상관리에더유의해야할것으로생각한다. REFERENCES 1) Kelman CD. Phaco-emulsification and aspiration. A new technique of cataract removal. A preliminary report. Am J Ophthalmol 1967;64:23-35. 2) Crema AS, Walsh A, Yamane Y, Nosé W. Comparative study of coaxial phacoemulsification and microincision cataract surgery. One-year follow-up. J Cataract Refract Surg 27;33:114-8. 3) Ku HC, Kim HJ, Joo CK. The comparison of astigmatism according to the incision size in small incision cataract surgery. J Korean Ophthalmol Soc 25;46:416-21. 4) Jee DH, Lee PY, Joo CK. The comparison of astigmatism according to the incision size in cataract operation. J Korean Ophthalmol Soc 23;44:594-8. 5) Nagaki Y, Hayasaka S, Kadoi C, et al. Bacterial endophthalmitis after small-incision cataract surgery: effect of incision placement and intraocular lens type. J Cataract Refract Surg 23;29:2-6. 6) Eifrig CW, Flynn HW Jr, Scott IU, Newton J. Acute-onset postoperative endophthalmitis: review of incidence and visual outcomes (1995-21). Ophthalmic Surg Lasers 22;33:373-8. 7) Taban M, Behrens A, Newcomb RL, et al. Acute endophthalmitis following cataract surgery: a systematic review of the literature. Arch Ophthalmol 25;123:613-2. 8) Miller JJ, Scott IU, Flynn HW Jr, et al. Acute-onset endophthalmitis after cataract surgery (2-24): incidence, clinical settings, and visual acuity outcomes after treatment. Am J Ophthalmol 25;139:983-7. 9) Monica ML, Long DA. Nine-year safety with self-sealing corneal tunnel incision in clear cornea cataract surgery. Ophthalmology 25;112:985-6. 1) Masket S. Is there a relationship between clear corneal cataract incisions and endophthalmitis? J Cataract Refract Surg 25;31:643-5. 11) Wallin T, Parker J, Jin Y, et al. Cohort study of 27 cases of endophthalmitis at a single institution. J Cataract Refract Surg 25;31: 735-41. 12) Choi JA, Chung SK, Kim HS. Comparative study of microcoaxial cataract surgery and conventional cataract surgery. J Korean Ophthalmol Soc 28;49:94-1. 13) Taban M, Rao B, Reznik J, et al. Dynamic morphology of sutureless cataract wounds--effect of incision angle and location. Surv Ophthalmol 24;49 Suppl 2:S62-72. 14) Torres LF, Saez-Espinola F, Colina JM, et al. In vivo architectural analysis of 3.2 mm clear corneal incisions for phacoemulsification using optical coherence tomography. J Cataract Refract Surg 26; 32:182-6. 15) Fine IH, Hoffman RS, Packer M. Profile of clear corneal cataract incisions demonstrated by ocular coherence tomography. J Cataract Refract Surg 27;33:94-7. 16) Vasavada V, Vasavada V, Raj SM, Vasavada AR. Intraoperative performance and postoperative outcomes of microcoaxial phacoemulsification. Observational study. J Cataract Refract Surg 27; 33:119-24. 17) Osher RH, Injev VP. Microcoaxial phacoemulsification: Part 1: laboratory studies. J Cataract Refract Surg 27;33:41-7. 18) Cavallini GM, Pupino A, Masini C, et al. Bimanual microphacoemulsification and Acri. Smart intraocular lens implantation combined with vitreoretinal surgery. J Cataract Refract Surg 27; 33:1253-8. 19) Schallhorn JM, Tang M, Li Y, et al. Optical coherence tomography of clear corneal incisions for cataract surgery. J Cataract Refract Surg 28;34:1561-5. 2) Dupont-Monod S, Labbé A, Fayol N, et al. In vivo architectural analysis of clear corneal incisions using anterior segment optical coherence tomography. J Cataract Refract Surg 29;35:444-5. 21) Calladine D, Tanner V. Optical coherence tomography of the effects of stromal hydration on clear corneal incision architecture. J Cataract Refract Surg 29;35:1367-71. 22) Elkady B, Piñero D, Alió JL. Corneal incision quality: Microincision cataract surgery versus microcoaxial phacoemulsification. J Cataract Refract Surg 29;35:466-74. 23) McGowan BL. Mechanism for development of endophthalmitis. J Cataract Refract Surg 1994;2:111. 24) Can I, Bayhan HA, Celik H, Bostancı Ceran B. Anterior segment optical coherence tomography evaluation and comparison of main clear corneal incisions in microcoaxial and biaxial cataract surgery. J Cataract Refract Surg 211;37:49-5. 25) Can I, Takmaz T, Genç I. Half-moon supracapsular nucleofractis phacoemulsification: Safety, efficacy, and functionality. J Cataract Refract Surg 28;34:1958-65. 26) Xia Y, Liu X, Luo L, et al. Early changes in clear cornea incision after phacoemulsification: an anterior segment optical coherence tomography study. Acta Ophthalmol 29;87:764-8. www.ophthalmology.org 885
- 대한안과학회지 213 년제 54 권제 6 호 - =ABSTRACT= The Morphological Changes in Main Corneal Incision (2.2 mm vs. 2.8 mm) Evaluated Using Anterior Segment Optical Coherence Tomography Jin Hyung Kim, MD, Tae Im Kim, MD, PhD, Eung Kweon Kim, MD, PhD, Hyung Keun Lee, MD The Institute of Vision Research, Department of Ophthalmology, Yonsei University College of Medicine, Seoul, Korea Purpose: To investigate wound characteristics and ultrastructural changes in the 2.2-mm and 2.8-mm main corneal incisions. Methods: Forty-four eyes of 34 patients undergoing cataract surgery were randomized to receive a 2.2-mm or 2.8-mm main corneal incision. All incisions were evaluated 1, 7, and 3 days postoperatively using anterior segment optical coherence tomography. The angle, length, maximal thickness of the incision, and if present, corneal gap length and incision gap area were calculated. The existence of Descemet s membrane detachment was recorded. Results: The mean endothelial gap length and gap area of the 2.2-mm wound were larger than the 2.8-mm, with the only statistically significant difference observed on postoperative day 3 (p =.15 and.27, respectively). There was no difference in the mean incision angle, length, and corneal thickness between the 2 incision sizes. The ratio of Descemet s membrane detachment increased with older age and low postoperative IOP, but not associated with incision size (p <.5). Conclusions: Both the 2.2-mm and 2.8-mm main corneal incisions showed excellent wound healing outcome without significant postoperative complications. Older patients with low postoperative IOP required a more careful wound care management. The incision parameters in the present study can be used as an indicator of the healing process to reduce wound-related complications. J Korean Ophthalmol Soc 213;54(6):877-886 Key Words: Anterior segment optical coherence tomography, Main corneal incision, Morphology, Phacoemulsification Address reprint requests to Hyung Keun Lee, MD Department of Ophthalmology, Gangnam Severance Hospital #211 Eonju-ro, Gangnam-gu, Seoul 135-72, Korea Tel: 82-2-219-344, Fax: 82-2-3463-149, E-mail: shadik@yuhs.ac 886 www.ophthalmology.org