각종 치과레이저의 Streptococcus mutans에 대한 증식 기능억제 효과

한강석,국중기,유소영,김화숙,박종휘,박현동,이상훈 大韓小兒齒科學會 2003 大韓小兒齒科學會誌 Vol.30 No.3

레이저의 구강내 산 생성 세균인 S. mutans에 대한 증식 및 기능 억제효과를 평가하기 위하여 S. mutans KCTC 3065가 포함된 세균 pellet에 Er:YAG 레이저와 Nd:YAG 레이저를 비접촉식 방법으로, 조사세기 50mJ, 조사시간 5초, 그리고 pulse repetition rate를 각각 10Hz와 30Hz로 하여 조사하고 세균 군락수, 산 생성능, 불용성 세포외다당류의 합성량을 측정하여 다음과 같은 결과를 얻었다. 1. Chinese ink로 photosensitization을 시행한 후 Nd:YAG 레이저를 조사한 경우가 S. mutans의 증식을 가장 많이 억제하였으며 Er:YAG 레이저 조사도 증식을 억제하였다. Chinese ink를 사용하지 않고 ND:YAG 레이저를 단독으로 조사한 경우는 S. mutans의 증식을 억제하지 못하였다. 2. Chinese ink로 photosensitization을 시행한 후 Nd:YAG 레이저를 조사한 경우가 일정기간 동안 S. mutans의 산생성능을 가장 많이 억제하였으며 Er:YAG 레이저 조사도 산 생성능을 억제하였다. Chinese ink를 사용하지 않고 Nd:YAG 레이저를 단독으로 조사한 경우는 S. mutans의 산 생성능을 억제하지 못하였다. Er:YAG 레이저와 Chinese ink로 photosensitization을 시행한 후 Nd:YAG 레이저를 조사한 경우는 pulse repetition rate가 클수록 전반적으로 세균의 산생성능을 더 많이 억제하였다. 3. 레이저 조사는 S. mutans의 불용성 세포외다당류의 합성에 영향을 미치지 못하였다. 이상의 결과로 보아 Er:YAG 레이저와 Chinese ink로 photosensitization을 시행한 후의 Nd:YAG 레이저 조사는 일정시간 동안 S. mutans의 증식과 산 생성능을 억제시키므로써 치아우식증 예방효과를 얻을 수 있다고 사료되나 억제효과가 오래가지 않아 임상적으로 효과를 얻기 위해서는 자주 조사를 해주어야 한다는 문제점을 안고 있어 임상적으로 치아우식증 예방이란 단독 목적으로 사용하기에는 실용성이 크지 않다고 사료된다. This was performed to evaluate the inhibitory effect of laser on the growth of S. mutans. The bacterial pallets containing S. mutans KCTC 3065 were irradiated with Er:YAG laser and Nd:YAG laser by non-contact method at an intensity of 50mJ for 5 sec with the pulse repetition rates of 10Hz and 30Hz, respectively. The following results were obtained on colony count, acid producing ability, and the amount of insoluble extracellular polysaccharide synthesis. 1. The irradiation of Nd:YAG laser after photosensitization with Chinese ink inhibited the proliferation of S. mutans the most, and the irradiation of Er:YAG also inhibited the proliferation. However, the irradiation of Nd:YAG laser alone could not inhibited the proliferation of S. mutans. The pulse repetition rate did not affect significantly on the proliferation of bacteria in overall. 2. The irradiation of Nd:YAG laser after the photosensitization with Chinese ink inhibited the acid production of S. mutans the most for a certain period of time. Er:YAG laser also inhibited acid production. When Nd:YAG laser was used alone, the acid production of S. mutans was not been inhibited. The irradiation of Nd:YAG laser after photosensitization with Chinese ink inhibited the acid production ability of bacteria the most as the pulse repetition rate increased. 3. Laser irradiation did not inhibited the synthesis of insoluble extracellular polysaccharide of S. mutans. From these results, we conclude that the irradiatioin of Er:YAG laser and Nd:YAG laser after photosensitization with Chinese ink would inhibit the proliferation and acid production by S. mutans, which may prenent dental caries. However, this effect does not last long time so that the laser irradiation should be repeated frequently in order to obtain clinical effect; thus, this laser irradiation would not have a clinical usefulness in preventing dental caries when used solely.

반복각막진무름에서 Nd:YAG Laser 치료와 보존적 치료의 비교

최문정(Moon jung Choi),정지원(Ji Won Jung),서경률(Kyoung Yul Seo),김응권(Eung Kweon Kim),김태임(Tae Im Kim) 대한안과학회 2015 대한안과학회지 Vol.56 No.5

목적: 반복각막진무름에서 Neodymium:Yttrium-Aluminum-Garnet (Nd:YAG) laser 치료와 보존적 치료의 효과를 비교하고자 한다. 대상과 방법: 반복각막진무름을 진단 받은 환자에서 Nd:YAG laser를 시행한 23안과 고삼투압제제를 포함한 보존적 치료를 시행한 24안을 대상으로 재발 유무, 양상, 빈도, 재발하기까지의 시간, 치료 후 최대교정시력, 합병증 유무에 대해 후향적 연구를 시행하였다. 결과: 재발률은 Nd:YAG laser를 받은 군에서 56.5%, 보존적 치료를 시행한 군에서 50.0%로 통계학적으로 유의미한 차이를 보이지 않았으나(p=0.654) 보존적 치료를 한 환자 중 재발한 12안 중 10안은 각막상피 결손을 동반한 형태로 재발하여 Nd:YAG laser군에서의 13안 중 5안보다 재발의 정도가 심함을 보여 주었다(p=0.041). 두 군 모두 시술 후 1년까지는 치료 성공률이 각각 64.1%, 60.5%였으나 시간이 지나면서 재발률이 상승하였고(p=0.649), 치료 후 최종 시력은 Nd:YAG laser를 받은 환자에서 0.05 ± 0.06 logMAR, 보존적 치료를 받은 환자에서 0.09 ± 0.08 logMAR로 유의한 차이를 보이지 않았으며(p=0.110) 두 군 모두에서 각막반흔 등의 합병증은 없었다. 결론: 반복각막진무름에서 Nd:YAG laser 치료와 보존적 치료의 재발률은 유의한 차이를 보이지 않았으나 재발 후 중증도는 Nd:YAG laser 치료가 보존적 치료보다 경미하였다. <대한안과학회지 2015;56(5):687-693> Purpose: To compare the treatment effects of neodymium:yttrium-aluminum-garnet (Nd:YAG) laser and conservative manage-ment in treatment of recurrent corneal erosion. Methods: Twenty-three eyes that received Nd:YAG laser treatment and 24 eyes that underwent conservative management in-cluding hyperosmotic agent were retrospectively reviewed for the rate and frequency of recurrence, presentation, time to re-currence, final visual acuity and complications. Results: The rate of recurrence in eyes treated with Nd:YAG laser was 56.5% and that in eyes with conservative management was 50.0%. The difference was not statistically significant (p = 0.654). However, 10 of 12 eyes that recurred after conservative treatment presented with macroform erosion at the time of recurrence, whereas 5 of 13 eyes that recurred after Nd:YAG laser had an accompanying epithelial defect (p = 0.041). After the Nd:YAG laser treatment or conservative treatment, 64.1% and 60.5% of the eyes, respectively, remained free from recurrence 1 year after treatment, however the success rate decreased over time (p = 0.649). The final visual acuity in the group that received Nd;YAG laser treatment was 0.05 ± 0.06 log MAR and 0.09 ± 0.08 log MAR (p = 0.649) in the group that received conservative management. None of the patients in either group experienced complications of corneal scarring. Conclusions: The difference in the recurrence rates between Nd:YAG laser treatment and conservative treatment were not stat-istically different, however, the severity of recurred episodes were milder in the eyes that received Nd:YAG laser treatment. J Korean Ophthalmol Soc 2015;56(5):687-693

무모생쥐 피부에 1320 nm Nd:YAG 레이저와 long-pulsed 1064 nm Nd:YAG 레이저의 조사 효과

김주용 ( Kim Ju Yong ),정현주 ( Jeong Hyeon Ju ),김동석 ( Kim Dong Seog ),이규석 ( Lee Gyu Seog ) 대한피부과학회 2004 대한피부과학회지 Vol.42 No.4

N/A Background: The treatment of facial rhytides has traditionally centered around methods that involve removal of the epidermis and superficial dermis, encouraging the production of a new epidermis with collagenesis and remodelling. But all of the resurfacing techniques lead to postoperative complications such as oozing, bleeding, infections, downtime as the skin begins to reepithelialize, and the occasional incidence of posttreatment, postinflammatory pigmentary changes. 1320㎚ and 1064㎚ wavelengths are nonspecifically absorbed in the human dermis and are unique for its significant horizontal scattering. These wavelengths, when used for localized facial areas, have been shown to produce new collagen formation and improvement in the quality of treated skin. Objective: The purpose of this study was to examine the effect of 1320㎚ Nd:YAG laser and long-pulsed 1064㎚ Nd:YAG laser irradiation on hairless mouse skin and rat skin. Methode: In this study, the effect of 1320㎚ Nd:YAG laser and long-pulsed 1064㎚ Nd:YAG laser irradiation were examined by Hematoxylin and eosin (H&E) stain, Masson`s trichrome stain, immunohistochemical stain for type I collagen and dot-blot hybridization for α1(Ⅰ) procollagen mRNA. Results: IN the H&E stain, Masson`s trichrome stain, and immunohistochemical stain of the hairless mouse skin, the number of collagen fibers with a greater density of fibers increased, compared to the non-irradiated controls on both the 1320㎚ Nd:YAG laser and the long-pulsed 1064㎚ Nd:YAG laser. In the dot-blot hybridization in the hairless mouse, levels of α1(Ⅰ) procollagen mRNA were increased 3.0-fold, 4.8-fold and 5.2-fold at each 1 week 4 weeks and 12 weeks after irradiation in 1320㎚ Nd:YAG laser and 1.8-fold and 2.1-fold at each 4 weeks and 12 weeks after irradiation in long-pulsed 1064㎚ Nd:YAG laser, compared to the non-irradiated controls. But in the 1320㎚ Nd:YAG laser irradiation on the rat, there is no significant change in the number and density of collagen fibers, compared to the non-irradiated controls. Conclusion: These results indicate that the 1320㎚ Nd:YAG laser and the long-pulsed 1064㎚ Nd:YAG laser may be a powerful up-regulator of collagen synthesis through significant dermal damage and the 1320㎚ Nd:YAG laser is better than the long-pulsed 1064㎚ Nd:YAG laser for collagen synthesis. Therefore, the 1320㎚ Nd:YAG laser can be more effective clinically than the long-pulsed 1064㎚ Nd:YAG laser for the treatment of photodamaged skin. (Korean J Dermatol 2004;42(4):385~391)

Rat Skin을 이용한 1064 nm Q-switched Nd:YAG 레이저, CO2 레이저, Er:YAG 레이저 조사 후 창상회복 과정에 대한조직학적 비교

김현조 ( Hyun Jo Kim ),이강모 ( Gang Mo Lee ),박영립 ( Young Lip Park ),이종석 ( Jong Suk Lee ),황규왕 ( Kyu Uang Whang ),이성열 ( Sung Yul Lee ) 대한피부과학회 2014 大韓皮膚科學會誌 Vol.52 No.4

Background: Laser therapy for various skin conditions is one of the most common procedures in dermatology. Recently, several articles described the use of 1064 nm Q-switched Nd:YAG lasers for the treatment of benign skinlesions. Such treatment is known to trigger its therapeutic effect through a photoacoustic effect and selectivephotothermolysis effect. However, only a limited number of articles have dealt with the theoretical base of thephotoacoustic effect of the 1064 nm Q-switched Nd:YAG laser. Objective: To compare the wound repair process and nonselective tissue heat damage induced by three differentlaser modalities: the CO2 laser, Er:YAG laser, and 1064 nm Q-switched Nd:YAG laser. Methods: We irradiated the skin of an albino rat (Sprague Dawleyⓡ, 200∼250 g) with CO2, Er:YAG, and 1064nm Q-switched Nd:YAG lasers. Skin biopsy specimens of the irradiated areas were collected on the first, fifth, andtenth day after laser exposure. For histologic analysis, the specimens were stained with the H&E, Verhoff-VanGieson, and Masson’s trichrome protocols. Results: Compared with other laser modalities, rat skin irradiated by the 1064 nm Q-switched Nd:YAG lasershowed the least amount of heat damage and the quickest tissue repair response to the damage. Conclusion: A 1064 nm Q-switched Nd:YAG laser with a photoacoustic effect capable of ablating the epidermisand dermis can be a proper treatment modality for the removal of benign skin lesions. The 1064 nm Q-switchedNd:YAG laser may be considered as an alternative treatment option for the treatment of benign skin lesions.

다른 재질의 비구면 인공수정체를 삽입한 이후, Nd:YAG 레이저 후낭절개술 시행률의 비교

김성현,박철용 대한안과학회 2015 대한안과학회지 Vol.56 No.2

목적: 백내장 환자에서 수정체초음파유화술과 후방인공수정체삽입술(서로 다른 인공수정체; SN60WF과 MI60)을 시행한 군에서 Nd:YAG 레이저 후낭절개술 시행률을 비교 분석하였다. 대상과 방법: 수정체초음파유화술과 후방인공수정체삽입술을 시행 받은 후, 6개월 이상 경과 관찰이 가능했던 278명 404안을 후향적으로 조사하였다. SN60WF 인공수정체를 삽입한 군과 MI-60 인공수정체를 삽입한 군의 성별, 연령, 추적 기간, Nd:YAG 레이저 후낭절개술 시행률을 비교 분석하였다. 결과: 추적 기간은 SN60WF 인공수정체를 삽입한 군에서 평균 28.1개월, MI-60 인공수정체를 삽입한 군에서 평균 24.3개월이었다. 연령은 두 군에서 평균 68.6세, 평균 71.3세였다. 추적 기간과 연령은 두 군 사이에 통계적으로 유의한 차이가 있었다(p<0.01).Nd:YAG 레이저 후낭절개술 시행률은 SN60WF 인공수정체를 삽입한 군에서 5.6% (231안 중 13안), MI-60 인공수정체를 삽입한 군에서 48% (173안 중 83안)이었으며, 두 군 사이에 통계적으로 유의한 차이가 있었다(p<0.01). 여성과 젊은 연령은 Nd:YAG 레이저 후낭절개술의 시행률과 통계적으로 유의한 연관성이 있었지만(p<0.01), 당뇨병 유무는 통계적으로 유의한 연관성이 없었다(p>0.05). 결론: 친수성 아크릴 비구면 인공수정체인 MI-60을 삽입한 군에서 소수성 아크릴 비구면 인공수정체인 SN60WF를 삽입한 군보다추적 기간 중 Nd:YAG 레이저 후낭절개술 시행률이 유의하게 높았다. Purpose: To compare neodymium-doped yttrium aluminum garnet (Nd:YAG) laser capsulotomy rates between 2 different aspheric intraocular lenses, SN60WF and MI-60, in patients who underwent cataract surgery. Methods: This retrospective study included 404 eyes of 278 patients who were followed up for at least 6 months after cataract surgery. Gender, age, follow-up period and Nd:YAG laser capsulotomy rates between the 2 different intraocular lens groups were compared. Results: The mean follow-up period was 28.1 months in the SN60WF group and 24.3 months in the MI-60 group and the mean age was 68.6 years and 71.3 years in each group, respectively. Follow-up period and age were significantly different between the 2 groups (p < 0.01). Nd:YAG laser capsulotomy rates were 5.6% (13 of 231 eyes) in the SN60WF group and 48% (83 of 173 eyes) in the MI-60 group. Nd:YAG laser capsulotomy rates were significantly higher in the MI-60 group (p < 0.01). Female gender and young age were associated with significantly increased Nd:YAG laser capsulotomy rates (p < 0.01); however, diabetes mellitus was not significantly associated with Nd:YAG laser capsulotomy rates. Conclusions: Nd:YAG laser capsulotomy rates were higher in the MI60 hydrophilic aspheric intraocular lens group than the SN60WF hydrophilic aspheric intraocular lens group.

The Effect of Combined Application of Argon and Nd-YAG Laser on Iridectomy in Rabbits

Park, Chan,Rhee, Sang Wook CATHOLIC MEDICAL CENTER 1987 Bulletin of the Clinical Research Institute Vol.15 No.1

Recently iridectomy using argon or Nd-YAG laser to treat narrow angle glaucoma has become popular, and is now a procedure of choice over the standard surgical technique. However, shock wave of Nd-YAG laser causes hemorrhage in almost all cases and high energy level of Nd-YAG laser, which is required for iridectomy, causes injuries to the lens and cornea. Furthermore, there is a tendency toward closure of the iridectomy site after argon laser application. We performed iridectomies by combined application of argon and Nd-YAG laser in pigmented rabbits to improve iris bleeding, iridectomy patency, and lens and corneal damage. The iridectomy patency and the lens and corneal damage were examined with scanning electron microscope. The rabbits that underwent laser iridectomies with only Nd-YAG laser were used as a control group. The following results were obtained: 1. The bleeding rate of the iridectomy in the combined application group was 2.4% and in the control group 98.8% proving the combined application of both laser to be highly effective. 2. In the experimental group, the patency rate of iridectomy was 33.3% at the energy level of 1 mJ, 66.6% at 2 mJ, 83.3% at 4 mJ, and 6 mJ, respectively. In the control group, the patency rate of iridectomy was 33.3% at the energy level of 4 mJ, 63.6% at 6 mJ, 83.3% at 8 mJ, respecively. At the same energy level, the experimental group showed a higher rate of patency than the control group. 3. In both the experimental and control groups, the lens damge was noted at the energy level of 6 mJ or higher. The lens was not affected by lower energy Nd-YAG laser. 4. In the experimental and control groups, the corneal damage was observed at the energy level of 8 mJ or higher. The cornea was not affected by low energy Nd-YAG laser. Based on the above results, it can be concluded that laser iridectomy by combined application of argon and Nd-YAG lasers results in a lower rate of bleeding, a higher rate of patency, and less damage to the lens and cornea as compared with iridectomy performed by Nd-YAG laser only.

발치후 Nd: YAG LASER 조사효과에 대한 임상적 연구

이상철(Sang Chull Lee),김여갑(Yeo Gab Kim),류동목(Dong Mok Ryu),이백수(Baek Soo Lee),오승환(Sung Hwan Oh),윤옥병(Ok Byung Yoon),박규태(Kyu Tae Park) 대한구강악안면외과학회 1997 대한구강악안면외과학회지 Vol.23 No.1

Nd:YAG laser is well absorbed to water, melanin, hemoglobin and thus, Nd:YAG laser may be used for bleeding control and extraction site sterilization where is easily contaminated by saliva and blood. Additionaly, Nd:YAG laser have analgesic effect by elevation of pain threshold. On the basis of Nd:YAG laser effects, we applied the Nd:YAG laser on extraction socket of 50 patients who visited to our department for lower third molar extraction and evaluated the effects of Nd:YAG laser on the bleeding control, pain relief, swelling reduction after tooth extraction. For the objective assesment on Nd:YAG laser effects, we made up the other 50 patients(control group) who were treated by conventional extraction method and compare the subjective and objective symptoms(pain relief, swelling and oozing time) between each group. The results were as follows: 1. The Nd:YAG laser was effective to relief of postextraction pain and most effective to 2 hours after extraction when local anesthesia disappears. 2. The Nd:YAG laser application was non-effective to reducing the facial swelling after extraction. 3. The Nd:YAG was effective to decrease the oozing time after extraction and the average time was 4 hours.

온도와 전류에 따른 레이저 다이오드의 발진파장 특성과 Nd:YAG 레이저의 출력 변화에 관한 연구

김하나,김경남,강만일,류지욱,김문원,김용기,박종욱,임형철,김덕현 한국물리학회 2008 새물리 Vol.57 No.4

The effects of laser-diode (LD) operating temperature and injection current on the LD emission spectra and the lasing threshold have been studied for effective pumping of a Nd:YAG laser. A red shift was observed in the center wavelength of the LD emission for increasing LD operating temperature and injection current. The average wavelength shift ratio was 0.31 nm/$^\circ$C at each operating temperature, and 0.22 nm/A at each injection current. The LD injection-current-based adjustment of the LD operating temperature enabled us to control the 808 nm center wavelength of LD emission for efficient pumping of a Nd:YAG crystal. When the center wavelength of the LD emission was 808 nm, the output power of the end-pumped Nd:YAG laser was up to 0.5 W higher than that of the non-808-nm center wavelength emission. A 1.3-W lower threshold input power was found with a 808-nm centered LD pump spectrum compared with a non-808-nm pump spectrum. Tailor-controlling the LD operating temperature for emission of an 808-nm centered LD spectrum proved to be not only an effective method for maximizing the LD's output power but also a stable condition for operating a Nd:YAG laser. Nd:YAG 고체레이저의 여기광으로 쓰이는 레이저 다이오드 (Laser diode;LD)의 동작 온도와 인가전류에 따른 여기 파장의 특성을 확인하였다. Nd:YAG 결정의 주 흡수파장인 808 nm를 중심으로 각각의 인가전류에서 레이저 다이오드의 동작 온도에 따른 평균 파장 변화율은 0.31 nm/$^\circ$C이고, 레이저 다이오드의 동작 온도 25 $^\circ$C에서의 인가전류에 따른 파장 변화율은 0.22 nm/A임을 확인하였다. 이 결과 레이저 다이오드의 인가전류에 따라 동작 온도를 변화시켜 레이저 다이오드의 여기 중심파장을 808 nm로 조절할 수 있었다. 이를 바탕으로 여기광의 파장에 따른 종여기 Nd:YAG 레이저의 출력특성을 알아 본 결과 여기광의 파장을 808 nm로 하여 Nd:YAG 결정을 여기하였을 때의 출력이 808 nm가 아닌 여기빔 보다 0.2 $\sim$ 0.5 W정도 큰 것을 확인하였다. 종여기 Nd:YAG 레이저의 문턱 출력은 808 nm로 여기하였을 때 808 nm가 아닌 여기빔 보다 약 1.3 W정도 낮은 것을 확인하였다. 본 연구를 통해 고체 레이저의 안정적이고 정확한 구동을 위해서는 레이저 다이오드의 여기 파장이 808 nm가 되도록 레이저 다이오드의 동작 온도를 조절하는 것이 Nd:YAG 레이저의 출력을 효율적으로 사용할 수 있는 방법임을 실험적으로 보였다.

소아에서 후방인공수정체 삽입술 후 발생한 후낭혼탁에 대한 야그레이저 후낭절개술의 효과

김태완,유영석,김성준,위원량,박기호,김미금,정호경,Tae-Wan Kim,Young-Suk Yu,Seong-Joon Kim,Won-Ryang Wee,Ki-Ho Park,Mee-Kum Kim,Ho-Kyung Choung 대한안과학회 2005 대한안과학회지 Vol.46 No.5

Purpose: To evaluate the effect of Nd:YAG laser capsulotomy for posterior capsular opacification (PCO) after posterior chamber intraocular lens (PC-IOL) implantation in children. Methods: Thirty eyes of 23 children underwent Nd:YAG laser capsulotomy for PCO after PC-IOL implantation. The frequency of laser capsulotomy, elapsed time between cataract surgery and capsulotomy, laser parameters, pre and postoperative visual acuity, complications and recurrence were reviewed. Results: From 108 eyes with intact posterior capsule after lensectomy, 30 (27.8%) were treated with Nd:YAG laser capsulotomy. The mean age at Nd:YAG laser capsulotomy was 7 years, the mean follow-up was 27 months, and the time interval between cataract operation and Nd:YAG laser capsulotomy was 13 months. Visual acuities of 20/40 or better were attained in 73% of eyes and visual acuities of 20/60 or less in 10% of eyes. PCO recurred in 12 eyes (40%), 10 of which were treated by performing a second laser capsulotomy, but the other two required a third laser capsulotomy. There was no relationship between the recurrence and the delay to initial laser capsulotomy, the amount of energy used for laser capsulotomy, or the patient age. One eye (3%) had corneal erosion, a bleeding from the pupillary margin and increased IOP; however, all responded well to medical treatment. Conclusions: Nd:YAG laser capsulotomy for PCO after PCL implantation in children offers a noninvasive and safe capability to create a clear visual axis. Although considered effective, there is a high likelihood that Nd:YAG laser capsulotomy will require revision.

각막이식 후 발생한 수여 잔류막에 대한 야그레이저 치료 효과

김용찬(Yong Chan Kim),황제형(Jae Hyung Hwang),김만수(Man Soo Kim) 대한안과학회 2015 대한안과학회지 Vol.56 No.5

목적: 각막이식 후 전방에 의도하지 않게 발생된 수여 각막의 잔류막을 빛간섭단층촬영으로 분석하고, Nd-YAG 레이저로 치료 효과를 알아보고자 했다. 대상과 방법: 본원에서 2007년 1월부터 2013년 5월까지 전층각막이식 및 심층부분각막이식을 시행 받은 742명 중, 전방에 잔류막이 관찰되고, 교정시력이 저하되어, Nd-YAG 레이저 치료 후 1년 이상 추적관찰이 가능했던 10명의 환자의 의무기록을 후향적으로 분석하였다. 기저질환으로 수포성각막병증 2안, 홍채각막내피증후군 2안, 각막이상증 1안, 기타 원인에 의한 각막혼탁 5안을 대상으로 하였다. Nd-YAG 레이저를 이용한 잔류막 제거술은 이식 후 평균 4.9개월에 시행하여, 시행 전후 시력의 변화, 내피세포 수의 변화, 각막두께의 변화, 내피세포부터 전방 내 잔류막까지의 거리와 내피세포 감소와 상관 관계를 조사하였다. 결과: 대상자는 10명 10안, 남자 5명 5안, 여자 5명 5안이었으며, 평균 나이는 56.9세였다. Nd-YAG 레이저를 이용한 전방 잔류막 제거술 12개월 뒤에 측정한 교정시력은 통계학적으로 유의한 시력호전을 보였다(p=0.039). Nd-YAG 레이저 1달 후 측정한 공여각막 내피세포 수는 통계학적으로 유의하게 감소한 결과를 보였다(p=0.01). 공여각막 내피세포부터 전방 내 잔류막까지의 거리는 평균712.0 ± 217.5 μm였으며, 이 거리와 공여각막 내피세포 손실과의 통계적인 연관성은 없었다(R2=0.39, p=0.072). 결론: 각막이식 후 전방에 의도치 않게 발생된 잔류막은 공여각막 내피세포로부터 가까운 거리에서 형성됨을 빛간섭단층촬영으로 확인하였다. Nd-YAG 레이저를 이용한 제거술은 시력개선에 효과적이나, 내피세포로부터 가까이 형성됨에 따라 유의한 내피세포의 감소를 보였다. <대한안과학회지 2015;56(5):664-671> Purpose: To evaluate the clinical efficacy and shortcomings of neodymium-doped yttrium aluminum garnet (Nd-YAG) laser membranotomy in inadvertently retained host membrane. Methods: Among 742 patients who underwent penetrating keratoplasty (PKP) and deep anterior lamellar keratoplasty (DALK) surgery at Seoul St. Mary's Hospital between January 2007 and May 2013 by a single surgeon, 10 patients had a thin, opaque membrane in the anterior chamber observed under slit lamp examination and both a subjective decrease in visual acuity and de-crease i best corrected visual acuity. A single surgeon performed membranotomy using the Nd-YAG laser at 4.9 months after graft surgery. In this study we compared the differences in visual acuity, endothelial cell count and correlations between distance from donor endothelium and retained host membrane and endothelial loss before and after the graft surgery. Results: Patients who had Nd-YAG laser membranotomy performed on the retained host membrane showed significant im-provements in visual acuity (p = 0.039). Donor endothelial cell count was significantly reduced 1 month after Nd-YAG laser. The average distance between donor endothelium and retained host membrane was 712.0 ± 217.5 µm. The distance and the de-creased donor endothelial cell count were not statistically correlated (R2 = 0.39, p = 0.072). There were no significant complica-tions after the laser membranotomy. Conclusions: Inadvertently retained host membrane forms close to the donor endothelium as identified on optical coherence to-mography (OCT) images. Nd-YAG laser membranotomy significantly affected clear vision but endothelial cell count loss was al-so observed. J Korean Ophthalmol Soc 2015;56(5):664-671