대한안과학회지 2019 년제 60 권제 1 호 J Korean Ophthalmol Soc 2019;60(1):91-95 ISSN 0378-6471 (Print) ISSN 2092-9374 (Online) https://doi.org/10.3341/jkos.2019.60.1.91 Case Report 녹내장으로진단되었던시삭증후군환자의신경절세포분석소견 Ganglion Cell Analysis in an Optic Tract Syndrome Patient Previously Diagnosed with Glaucoma 김진우 박미라 정윤혜 Jinu Kim, MD, Mi Ra Park, MD, PhD, Younhea Jung, MD, PhD 가톨릭대학교의과대학여의도성모병원안과학교실 Department of Ophthalmology, Yeouido St. Mary s Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea Purpose: To report the results of ganglion cell analysis in a patient with optic tract syndrome who was previously diagnosed with glaucoma. Case summary: A 32-year-old male, who had been diagnosed with glaucoma 12 years ago, but had not visited an ophthalmology clinic since then, came to our clinic for evaluation of his glaucoma. Both eyes showed an increased cup-to-disc ratio and temporal pallor of the disc. Retinal nerve fiber layer (RNFL) optical coherence tomography showed thinning of the superior, inferior, and temporal peripapillary RNFL in both eyes. On ganglion cell analysis (GCA), ganglion cell layer thinning in the nasal region of the right eye and in the temporal region of the left eye was observed. The visual field test showed right incongruous homonymous hemianopsia. After the atrophic change of the left optic tract was confirmed by orbit magnetic resonance imaging, he was diagnosed with left optic tract syndrome. Conclusions: We report the results of GCA in a case of optic tract syndrome, previously diagnosed as glaucoma. GCA can be useful when diagnosing optic tract syndrome. J Korean Ophthalmol Soc 2019;60(1):91-95 Keywords: Ganglion cell analysis, Glaucoma, Optic nerve, Optic tract syndrome 시삭은시각교차로부터가쪽무릎체까지뻗어나온백색질이다. 시삭의특징적인해부학적구조때문에시삭의병변은여러가지전형적인임상양상을유발한다. 선천성시삭증후군은편층시삭에국한된형성저하때문에발생하는병으로병변반대측의불일치동측반맹, 반대측눈의구심 Received: 2018. 6. 7. Revised: 2018. 8. 23. Accepted: 2018. 12. 20. Address reprint requests to Younhea Jung, MD, PhD Department of Ophthalmology, Yeouido St. Mary s Hospital, College of Medicine, The Catholic University of Korea, #10 63-ro, Yeongdeungpo-gu, Seoul 07345, Korea Tel: 82-2-3779-1520, Fax: 82-2-761-6869 E-mail: write2une@catholic.ac.kr * Conflicts of Interest: The authors have no conflicts to disclose. 동공운동장애, 역행성축삭변성 (retrograde axonal degeneration) 에따른시신경위축이특징적인임상양상이다. 1,2 뇌의자기공명 (magnetic resonance, MR) 영상을통해확진을내릴수있지만특징적인임상소견을간과하기쉽고, 일반적으로 MR 영상에서병변이두드러지지않으며 MR 영상의해상력이충분하지않은경우가많아진단에어려움이있다. 1-3 하지만검사기술의발달과검사장비의개선으로과거에비해시삭증후군을진단하기가용이해졌다. 덕분에기존에다른시신경질환, 그중에서도특히녹내장으로진단받았다가시삭증후군으로다시진단을받게된환자들에대한증례보고가발표된바있다. 4 망막신경섬유층빛간섭단층촬영 (retinal nerve fiber layer optical coherence tomography, RNFL OCT) 을사용하여시삭증후군환자를진단한 c2019 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. 91
- 대한안과학회지 2019 년제 60 권제 1 호 - 증례가보고된바있으나 5 이측, 비측망막신경섬유는시신경유두가아니라황반을기준으로하기때문에동측눈의위, 아래궁상신경섬유다발의위축, 반대쪽눈의이측및비측망막신경섬유층의위축으로나타나는시삭증후군의 RNFL OCT 소견은임상적으로간과하기가쉽다. 기존 RNFL OCT보다 ganglion cell analysis (GCA) 가수직경선을반영하는망막신경섬유층위축을발견하는데더유용하다는보고가있는데 6 시삭증후군의진단에있어 GCA의활용은보고된바가없다. 타병원에서양안의녹내장진단을받았으나특징적인임상소견및 GCA와 MR 영상을통해시삭증후군으로진단된 1예에대하여보고하고시삭증후군환자에서 GCA 결과에대해보고하고자한다. 증례보고 32세남자환자가 12년전타병원에서양안녹내장진단받았으나특별한치료없이지내오다가다시녹내장에대한검사를원하여내원하였다. 당뇨, 고혈압등의전신질환은없었으며안과적수술력, 외상력또한없었다. 녹내장가족력에대해서환자는부인하였다. 양안교정시력우안 0.8, 좌안 0.8로확인되었으며자동각막굴절력계 (RK-F1 ; Canon, Tokyo, Japan) 로측정한현성굴절력은우안 -1.75Ds =-1.75Dc 축 178, 좌안 -1.75Ds=-0.75Dc 축 8 였다. 골드만안압계로측정한안압은우안 12 mmhg, 좌안 12 mmhg 이었고, 타병원에서측정했던각막두께는우안 584 μm, 좌안 576 μm였다. 상대구심동공장애는없었고이시하라색각검사에서색각저하소견은관찰되지않았다. 양측시신경유두함몰비는증가되었고경미한시신경유두이측창백이관찰되었다 (Fig. 1). 골드만삼면경을이용하여전방각을 Figure 2. Results of RNFL optical coherence tomography (OCT). RNFL OCT showed thinning of superior, inferior and temporal RNFL of both eyes. RNFL = retinal nerve fiber layer; N = nasal; T = temporal. Figure 1. Results of fundus photography. Both optic discs showed increased cup-disc ratio and mild temporal pallor. 92
- 김진우외 : 시삭증후군 1 예 - Figure 3. Results of ganglion cell analysis. On ganglion cell analysis, thinning of the ganglion cell layer was prominent in the nasal region of the right eye and the temporal region of the left eye respecting the vertical meridian. Figure 5. Mild atrophic change of the left optic tract was observed (arrow) in T2-weighted orbit magnetic resonance imaging. 평가하였고양안모두 Spaeth 분류법상 40Dr로전방각은개방되어있었다. Cirrus HD-OCT (Carl Zeiss Meditec Inc., Dublin, CA, USA) 를이용하여유두주위망막신경섬유층의두께를측정하였는데양안모두상, 하, 이측신경섬유다발이얇아진소견이보였다 (Fig. 2). GCA상에서는망막 신경절세포 + 속얼기층 두께가특징적으로수직경선을기준으로하여우안은비측, 좌안은이측에서두드러지게감소해있었다 (Fig. 3). Humphrey 자동시야검사계 (Carl Zeiss Meditec, Inc.) 의 Swedish Interactive Thresholding Algorithm (SITA) 24-2를이용한시야검사에서이에합당한양안의우측불일치시야결손이관찰되었다 (Fig. 4). 이어시행한안와 (magnetic resonance imaging) 상에서우측시삭에비해좌측시삭이경도의위축성변화를보이는것을확인하였고 (Fig. 5), 좌측의시삭증후군을진단할수있었다. 고 찰 Figure 4. Results of visual field analysis. Right incongruous homonymous hemianopsia was shown in Humphrey visual field test 24-2, which is in accordance with the retinal nerve fiber layer and ganglion cell analysis test results. 시삭은동측눈의이측망막신경섬유와시각교차에서엇갈려교차된반대측눈의비측망막신경섬유로구성되어있다. 시삭의신경섬유들중대부분은가측무릎체로뻗어나가며반대측의시야를담당하게된다. 따라서한쪽시삭의손상은반대측의동측성반맹을유발한다. 7 시삭에포함된신경섬유들은세포체가망막에위치하고 93
- 대한안과학회지 2019 년제 60 권제 1 호 - 있는신경절세포의축삭들이다. 어느위치에서든이축삭이손상을입게되면역행성축삭변성이일어나결국시신경유두창백이발생하게된다. 시신경유두의비측과황반의비측영역에해당하는망막영역에서나온축삭은주로시신경유두로수평하게주행하여들어간다. 이축삭들은이측시야의대부분을담당하며시각교차에서반대측으로교차하게된다. 반면시신경유두의상극과하극부는이측망막에서나온신경섬유들로구성되어있다. 이러한해부학적특징때문에이측시야를담당하는시각교차에서교차된신경섬유의손상은시신경유두의상극부과하극부는그대로남겨둔채시신경유두의중앙부를가로지르는양상의시신경유두위축 (bowtie atrophy) 를일으키고, 비측시야를담당하는시각교차에서교차되지않은신경섬유의손상은중앙부는보존한채상극부와하극부에서위축을일으킨다. 8 시삭에병변이있을때시력과색각은보통정상으로유지되는데이는시삭의병변이반대측눈의비측황반부섬유와동측눈의이측황반부섬유에만영향을주기때문이다. 따라서양측시삭에병변이있거나시각교차부위에병변이있지않은한시력과색각에서이상소견이관찰되는경우는드물다. 9 시삭은동공빛반사에관여하는신경섬유들또한포함하고있다. 구심동공운동장애는보통시야손상이더광범위한눈에서발생하며한쪽시삭이완전히손상된경우이측시야손실이나타나는반대측눈에서관찰된다. 이는이측망막에비해비측망막이더광범위하며시각교차에교차를하는신경섬유가교차를하지않는신경섬유보다 53:47 비율로더많기때문이다. 10 시삭증후군은선천성인경우한측의시삭의장애로발생한다고생각되나정확한병리기전은아직명확히밝혀지지않았다. 가측무릎체나후두엽의국소적인손상이나허혈에의한역행성축삭변성이원인일것으로생각되고있다. 2 이외에도외상이나두개인두종및뇌하수체선종과같은종양, 동맥류등의원인에의해이차적으로발생할수도있다. 7 본증례에서는병변반대안시신경유두에서전형적인 Bowtie appearance는보이지않은채양안에서시신경유두이측창백만이관찰되었고상대동공구심장애도관찰되지않았으나시야검사상에서우측의동측반맹, GCA 검사상의우안의비측, 좌안의이측에서 신경절세포층 + 속얼기층 의두드러진두께감소확인을통해좌측시삭증후군을강력히의심할수있었다. 이측, 비측망막신경섬유는황반을기준으로나뉘기때문에 RNFL OCT보다 GCA 검사에서더잘나타날수있어 6 GCA가시삭증후군의진단에임 상적으로더유용할수있다. 본증례의경우뚜렷한외상과거력이없었고, MR 영상에서도종양, 동맥류등다른병변이관찰되지않았기에선천성시삭증후군을의심할수있겠다. 한편본증례에서양안의시신경유두함몰비는매우컸고, RNFL OCT에서좌안의이측과우안의상이측, 하이측유두주위망막시신경섬유층두께가감소해있었으며, GCA 검사상좌안의비측, 우안의하이측에서도 신경절세포층 + 속얼기층 두께가감소해있었다. RNFL OCT상에서관찰되는병변동측눈의이측유두주위망막시신경섬유층두께감소는기존시삭증후군증례보고에서언급된바있으나 4,11 그외다른징후들은시삭증후군만으로는설명하기어려워비록아직녹내장성시야손상은명확하지않지만이에대해향후정기적인경과관찰이필요하겠다. 저자들은이미녹내장으로진단되었던환자를기타시신경병증을의심할만한명확한임상적단서가없는상태에서 GCA를통해시삭증후군으로진단해나간과정을기술함으로써본증례보고를통해시신경질환의정확한진단에있어신경안과적소견에대한주의깊은평가와해석이중요함을다시한번강조하고자하였다. 녹내장으로진단되었다가 GCA를통해시삭증후군을강력히의심하여추가적인 MR 영상검사를통해시삭증후군을진단할수있었던환자에대해보고하고 GCA가시신경질환을감별할때유용하게쓰일수있음을알리고자한다. REFERENCES 1) el Gammal T, Brooks B, Harbour R, et al. MR of uncommon congenital and vascular lesions of the intracranial visual pathways. Neuroradiology 1990;32:488-91. 2) Margo CE, Hamed LM, McCarty J. Congenital optic tract syndrome. Arch Ophthalmol 1991;109:1120-2. 3) Murphy MA, Grosof DH, Hart WM Jr. Congenital optic tract syndrome: magnetic resonance imaging and scanning laser ophthalmoscopy findings. J Neuroophthalmol 1997;17:226-30. 4) Lee EJ, Kim JH, Hwang JM. Congenital optic tract syndrome misdiagnosed with normal tension glaucoma. Graefes Arch Clin Exp Ophthalmol 2016;254:2481-3. 5) Kim JY, Lee HJ, Kwag JY, Lee YH. The optical coherence tomography findings of optic tract syndrome. J Korean Ophthalmol Soc 2013;54:1144-8. 6) Shin HY, Park HY, Choi JA, Park CK. Macular ganglion cell-inner plexiform layer thinning in patients with visual field defect that respects the vertical meridian. Graefes Arch Clin Exp Ophthalmol 2014;252:1501-7. 7) Savino PJ, Paris M, Schatz NJ, et al. Optic tract syndrome. A review of 21 patients. Arch Ophthalmol 1978;96:656-63. 8) Unsöld R, Hoyt WF. Band atrophy of the optic nerve. The histology of temporal hemianopsia. Arch Ophthalmol 1980;98:1637-8. 94
- 김진우외 : 시삭증후군 1 예 - 9) Newman SA, Miller NR. Optic tract syndrome. Neuro-ophthalmologic considerations. Arch Ophthalmol 1983;101:1241-50. 10) Kupfer C, Chumbley L, Downer JC. Quantitative histology of optic nerve, optic tract and lateral geniculate nucleus of man. J Anat 1967;101(Pt 3):393-401. 11) Hsu CY, Lai YH, Hsu SY, et al. Optical coherence tomography (OCT) findings in patients with optic tract syndrome. Taiwan J Ophthalmol 2011;1:16-20. = 국문초록 = 녹내장으로진단되었던시삭증후군환자의신경절세포분석소견 목적 : 녹내장으로생각되었다가시삭증후군으로최종진단된환자 1 예를경험하여, 신경절세포분석의소견과유용성을보고하고자한다. 증례요약 : 32 세남자환자가 12 년전타병원에서양안녹내장을진단받았으나특별한치료없이지내오다가다시녹내장에대한검사를원하여내원하였다. 양측시신경유두함몰비는증가되어있었고경미한시신경유두이측창백이관찰되었다. 망막신경섬유층빛간섭단층촬영검사상에서양안모두상, 하, 이측유두주위신경섬유층이얇아진소견이보였고신경절세포분석 (ganglion cell analysis) 에서망막시신경세포층두께가수직경선을기준으로우안은비측, 좌안은이측에서두드러지게감소해있었다. 시야검사에서이에합당한양안의우측불일치시야결손이관찰되었다. 이어시행한안와자기공명영상에서우측시삭에비해좌측시삭이경도의위축성변화를보이는것을확인하였고좌측의시삭증후군을진단하였다. 결론 : 녹내장으로진단되었다가시삭증후군으로진단된환자의신경절세포분석소견을보고하며이러한환자에서신경절세포분석소견이진단에도움이될것이라생각한다. < 대한안과학회지 2019;60(1):91-95> 김진우 / Jinu Kim 가톨릭대학교의과대학여의도성모병원안과학교실 Department of Ophthalmology, Yeouido St. Mary s Hospital, College of Medicine, The Catholic University of Korea 95