대한안과학회지 2011 년제 52 권제 11 호 J Korean Ophthalmol Soc 2011;52(11):1269-1274 pissn: 0378-6471 eissn: 2092-9374 http://dx.doi.org/10.3341/jkos.2011.52.11.1269 = 증례보고 = 각막굴절교정학콘택트렌즈가근시및난시의진행에미치는영향 이원희 1 박영기 1 서종모 2,3 신종훈 4 이원희 박영기안과의원 1, 서울대학교공과대학전기공학부 2, 서울대학교병원안과 3, 부산대학교의학전문대학원안과학교실 4 목적 : 각막굴절교정렌즈착용이근시진행억제에미치는영향을알아보고자하였다. 대상과방법 : 근시및난시를대상으로각막굴절교정렌즈를 1 년이상착용한 144 안을착용전과렌즈착용을중지한지 2-4 주후에조절마비굴절검사및각막곡률반경을측정하여굴절력의차이를비교하였다. 근시및난시를안경으로교정한대상을대조군으로 190 안을선정하여렌즈착용군과비교하였다. 나이, 근시및난시와의관계, 근시및난시의진행과착용시간과의연관성을각각비교하였다. 결과 : 각막굴절교정렌즈를사용한대상의구면렌즈대응치은평균 -3.36 ± 1.96D 였으며, 난시는평균 -0.86 ± 0.72D, 기간은평균 3.41 ± 1.5 년이었고나이는평균 10.31 ± 2.37 년이었다. 렌즈를착용한경우의 1 년간근시진행은평균 0.25 ± 0.31D 로대조군 0.62 ± 0.39D 와유의한차이가있었고 (t-test, p<0.01), 난시진행도렌즈를착용한군이평균 0.06 ± 0.2D 로대조군 0.15 ± 0.21D 와유의한차이를보였다 (t-test, p<0.01). 두군간의나이, 근시 난시의양및진행정도, 착용기간은유의한차이가없었다 (t-test, p>0.01). 결론 : 한국인에있어서각막굴절교정렌즈는안경을사용하는경우보다근시와난시의진행을억제시키는유용한방법으로생각한다. < 대한안과학회지 2011;52(11):1269-1274> 한국인의근시의빈도는 Kim and Koo 1 에의하면초등학생의 23%, 중학생의 47.3%, 고등학생의 66.9% 라고알려져있고, Han et al 2 에의하면근시가초등학교 4학년에서는 50.1% 라고보고되고있다. 동남아의경우에도근시의빈도가높은데, 2004년도싱가포르의 Quek et al 3 에의하면 10대의 78% 에서근시가있다고보고하였다. 근시는한번생기면거의대부분진행하고근시진행을억제시키기위한여러방면의노력에도불구하고현재까지근시진행을억제시키는확실한방법은없는실정이다. 한국에서의근시진행에대한보고를보면, Lee et al 4 은사춘기이전의학생들에서사춘기이후보다근시진행이더많이된다고하였으며, Kim and Min 5 은남녀차이는없고근시가발생한지 1년이내에더많이진행한다고보고하고있다. 근시의진행을억제하는방법으로조절의완화, 약물치료, 안경저교정, 산소투과구면하드렌즈등이사용되어왔고, 최근에는각막굴절교정렌즈에의한연구가많이진 접수일 : 2011년 3월 15일 게재허가일 : 2011년 9월 27일 심사통과일 : 2011 년 6 월 17 일 책임저자 : 이원희서울시송파구잠실동 184-10 이원희 박영기안과의원 Tel: 02-423-2277, Fax: 02-423-2274 E-mail: leeeye47@hanmail.net 행되고있다. 각막굴절교정학 (orthokeratology) 은경성콘택트렌즈를이용하여각막의곡률을변화시켜굴절이상을감소시키거나제거하는방법인데, 국내에서는이와관련된근시의진행억제효과에관한연구는거의전무한실정이다. 이에저자들은각막굴절교정렌즈가근시의진행억제에미치는영향을알아보기위해 1년이상각막굴절교정렌즈를착용한환자에서착용전후조절마비굴절검사및각막곡률반경을분석하고안경착용군인대조군과각각비교하고자하였다. 대상과방법 연구계획 1994년 1월부터 2008년 3월까지본원에내원한 74명 144안을대상으로각막굴절교정렌즈를 1년이상착용받은자를대상으로하였으며, 착용전에조절마비굴절검사및각막곡률반경을측정하였고, 렌즈착용을중지한뒤각막이원래상태로돌아온것을확인후약 2-4주후에조절마비굴절검사및각막곡률반경을측정하여착용전후의굴절치차이를계산하였다. 각막굴절교정렌즈는밤에취침시착용하여아침에기상시렌즈를빼주는것을기준으로 www.ophthalmology.org 1269
- 대한안과학회지 2011 년제 52 권제 11 호 - 하루평균 8시간매일착용하는것을원칙으로하였다. 대조군은본원에서안경을착용하여조절마비굴절검사를받은 190안을대상으로하였고, chi-square test을이용하여실험군과차이를확인하였다. 나이와근시와의관계, 초기근시양과근시진행정도, 착용기간과근시진행정도, 초기근시양과난시진행정도, 초기난시와난시진행정도, 착용기간과난시진행등나이, 근시정도, 추적관찰기간을맞춘 111안과대조군의비교분석은 paired t-test 을이용하여통계학적유의성을확인하였는데기준은 p<0.01 로하였다. 자료수집및방법시력, 자동굴절검사, 현성굴절검사, 안압, 각막지형도, 각 막두께, 안장축및전방깊이, 각막내피세포검사를하였으며, 본연구의대상에사용된렌즈는렌즈의크기및성상이유사한 LK렌즈 (Lucid Korea lens, Lucid Korea, Seoul, South Korea), OK렌즈 (Ortho-keratology lens, Contex, Sherman Oaks, CA, USA), 에메랄드렌즈 (Emerald lens, Euclid, Herndon, VA, USA), Vipok 렌즈 (Vipok lens, Vipok, Alhambra, CA, USA) 등이었다. 결과 각막굴절교정렌즈를착용한대상안의평균근시는 -3.36 ± 1.96D이었고, 평균난시는 -0.86 ± 0.72D, 평균착용기간은 3.41 ± 1.5년, 대상군의평균나이는 10.31 ± 2.37년이었다. 남녀비율은 93:51로여자가월등히많았으 Figure 1. The myopic progression for one year was compared between orthokeratology lens and glasses wearer. The myopic progression of orthokeratology lens wearing was 0.2 5 ± 0.31 D, and 0.62 ± 0.39 D in wearing glasses group, respectively. The differences were statistically significant between two groups (t-test, p < 0.01). Figure 3. There was no significant relationship between age of first lens wearing and myopic progression Figure 2. The mean astigmatic progression was 0.06 ± 0.22 D in orthokeratology lens wearing, and 0.15 ± 0.21 D, in wearing glasses group respectively. There was statistically significant difference between two groups (t-test, p < 0.01). Figure 4. There was no significant relationship between myopia before wearing the first lens and myopic progression 1270 www.ophthalmology.org
- 이원희외 : Ortho-K 렌즈의근시 난시억제효과 - 며, 좌및우안의빈도는 71:73로거의차이가없었다. 콘택트렌즈를착용한군의 1년간평균근시진행은 0.25 ± 0.31D, 나이, 근시정도, 추적관찰기간을콘택트렌즈를착용한군과맞춘대조군은 0.62 ± 0.39D로통계학상근시로의진행이유의하게억제되는양상을보였으며 (t-test, p<0.01) (Fig. 1), 난시의진행도콘택트렌즈를착용한군이 0.06 ± 0.22D, 대조군이 0.15 ± 0.21D로역시난시의진행이다소유의하게억제되는차이를보였다 (t-test, p<0.01) (Fig. 2). 처음렌즈착용시작나이와근시진행의관계 (Fig. 3), 처음렌즈착용시근시의양과초기근시양과근시진행정도 (Fig. 4), 렌즈를착용한기간과시술기간과근시진행정도 (Fig. 5), 처음렌즈착용시근시의양과초기근시양과난시진행정도 (Fig. 6), 처음렌즈착용시난시의양과초기난시와난시진행정도 (Fig. 7), 렌즈를착용한기간과시술기간과난시진행 (Fig. 8) 은모두상관관계가없었다 (t-test, p>0.01). 고찰 근시진행을억제하기위한방법은조절의완화, 약물치료, 안경저교정, 산소투과구면하드렌즈, 각막굴절교정렌즈등여러가지방법이알려져있다. 첫째, 조절을완화 (relaxation of accommodation) 시키는방법과관련하여, 안경의중심부에서아래로갈때안경도수를점차로줄여가까이볼때조절력을감소시키는것과근시진행과의관계를연구하였는데, Edwards et al 6 은이러한안경의착용이근시진행을억제하는효과가없다고발표하였으나, Gwiazda et al 7 은첫 1년동안만효과가있다고발표하였고, 조절성내사시가있는근시에서는이방법이효과적이라고발표되었다. 8 둘째, 약물치료로근시를억제하는방법으로피렌제핀 (pirenzepine), 아트로핀 (atropin) 이알려져있는데, Siatkowski et al 9 은피렌제핀은첫 1년동안만근시진행을억제시키는효과가있었다고발표하였으며, Siatkowski et al 10 은 2% Figure 5. There was no significant relationship between duration of orthokeratology lens wearing and myopic progression Figure 7. There was no significant relationship between the astigmatism before wearing the first lens and astigmatic progression Figure 6. There was no significant relationship between myopia before wearing the first lens and astigmatic progression Figure 8. There was no significant relationship between duration of orthokeratology lens wearing and astigmatic progression www.ophthalmology.org 1271
- 대한안과학회지 2011 년제 52 권제 11 호 - Table 1. A six-year-old boy wore the spectacle for 2 year and 8 months. The myopic progression was 1.5 D in the right eye and 2.63 D in the left eye Age Right eye Left eye 6 yr 10 m -0.25 D sph with -0.25 D cyl axis 10-0.37 D sph with -0.37 D cyl axis 160 7 yr 1 m -0.62 D sph -0.87 D sph 7 yr 5 m -1.12 sph -1.37 D sph with -0.37 D cyl axis 160 8 yr -1.12 sph with -0.50 D cyl axis 11-0.75 D sph with -0.75 D cyl axis 160 8 yr 5 m -1.37 sph with -1.00 D cyl axis 5-2.12 D sph with -1.12 D cyl axis 152 9 yr -1.50 sph with -1.12 D cyl axis 9-2.50 D sph with -1.12 D cyl axis 153 9 yr 6 m -1.75 sph with -1.25 D cyl axis 10-3.00 D sph with -1.50 D cyl axis 160 Table 2. After wearing the orthokeratology lenses, myopic progression was 1.25 D in the right eye and 1.0 D in the left eye for 5 year and 3 months Age Right eye Left eye 11 yr 3 m -2.75 D sph with -1.25 D cyl axis 16-3.25 D sph with -2.25 D cyl axis 165 (Ortho K started) K : H:43.00 V:45.00 K : H:43.00 V:45.50 16 yr 6 m -1.5 D sph with -1.5 D cyl axis 2-2.25 D sph with -1.00 D cyl axis 157 (Lens changed) K : H:43.00 V:45.00 K : H:43.12 V:45.00 피렌제핀안과용겔로 2년동안의치료한결과근시진행을억제시키는데효과가있다고하였다. 셋째, 안경을저교정함으로써근시진행을억제시키는방법은일반적인예상과는달리효과가없는것으로알려져있다. 11 넷째, 산소투과구면하드렌즈의경우 Katz et al 12 은 6-12세근시에서 2년동안산소투과구면하드렌즈착용군과안경착용군과의근시진행에있어서는유의한차이가없다고도보고하였다. 어떤보고에서는산소투과구면하드렌즈착용군에서는 3년간 1.56 ± 0.95D, 소프트렌즈착용군에서 2.19 ± 0.89D의근시진행차이를보여두군의굴절률은유의한차이가났지만안구의장축에서는유의한차이가나지않는다고하였다. 13 2005년 Global Orthokeratology Society 학술대회의 contact lens and myopia progression (CLAMP) 연구의결과에의하면산소투과구면하드렌즈가근시억제에영향을미치지만그효과는각막의곡률반경의변화때문으로설명하고, 안구의장축의변화는차이가없어근시의영구적인억제효과는아닐것이라고보고하기도하였다. 13 각막굴절교정학은경성콘택트렌즈를이용하여각막의곡률을변화시켜굴절이상을감소시키거나제거하는방법으로, Cheung et al 14 에의하면 13세남아에서각막굴절교정렌즈를착용한좌안은 2년간굴절상태는 0.25D 근시와 0.5D난시가감소하였고안장축이 0.1 mm 증가한반면, 착용하지않은우안의안장축은 0.34 mm 증가하였으며그에따라우안의근시도 0.75D 증가하였다고보고하였다. 각막굴절교정학의근시진행억제에대한기전은아직명확히밝혀지지는않았지만 Charman et al 15 은각막굴절교정렌즈의착용을받은눈의근시감소는주로시야의 10도정도에 서많이생기고, 시야의 30도이상에서는근시의감소가적게생긴다고하였으며, 안경렌즈를통하여들어오는빛은주변부로갈수록망막의주변부로가서초점을맞추려고하기때문에, 안구가커지는경향이있지만각막굴절교정렌즈의착용시에는주변부의빛이망막의전방에맺히므로안장축의길이의변화에는영향을미치지않으므로근시진행억제의효과가있는것으로설명된다. 본연구에서도각막굴절교정렌즈의착용전과후의굴절상태를명확하게관찰할수있었는데, 예를들면 6세남아의경우 2년 8개월동안안경을착용하여우안 1.5D, 좌안 2.63D의근시진행을보였으나각막굴절교정렌즈를착용한 5년 3개월동안은우안 1.25D, 좌안 1.0D만의근시진행을보였다 (Table 1, 2). 본연구에서 1년이상각막굴절교정렌즈를착용한 144 안과안경교정을받은 190안을비교한결과각막굴절교정렌즈를착용한군에서유의하게근시와난시의진행이억제됨을알수있어, 한국인의근시에있어서각막굴절교정렌즈는근시와난시의진행을억제시키는한방법으로이용될수있을것으로생각한다. 참고문헌 1) Kim JC, Koo BS. A study of prevailing features and causes of myopia and visual impairment in urban school children. J Korean Ophthalmol Soc 1988;29:165-81. 2) Han ER, Kang JE, Jun RM, Choi KR. Changes of refractive errors and optometric values in fourth graders at an urban elementary school in Korea. J Korean Ophthalmol Soc 2007;48:1119-25. 3) Quek TP, Chua CG, Chong CS, et al. Prevalence of refractive errors in teenage high school students in Singapore. Ophthalmic Physiol Opt 2004;24:47-55. 1272 www.ophthalmology.org
- 이원희외 : Ortho-K 렌즈의근시 난시억제효과 - 4) Lee MJ, Lee YH, Shyn KH. The progression of myopia with age. J Korean Ophthalmol Soc 1987;28:151-5. 5) Kim SY, Min BM. Myopic progression according to the age of onset in childhoods. J Korean Ophthalmol Soc 1998;39:721-7. 6) Edwards MH, Li RW, Lam CS, et al. The Hong Kong progressive lens myopia control study: study design and main findings. Invest Ophthalmol Vis Sci 2002;43:2852-8. 7) Gwiazda J, Hyman L, Hussein M, et al. A randomized clinical trial of progressive addition lenses versus single vision lenses on the progression of myopia in children. Invest Ophthalmol Vis Sci 2003;44:1492-500. 8) Gwiazda JE, Hyman L, Norton TT, et al. Accommodation and related risk factors associated with myopia progression and their interaction with treatment in COMET children. Invest Ophthalmol Vis Sci 2004;45:2143-51. 9) Siatkowski RM, Cotter S, Miller JM, et al. Safety and efficacy of 2% pirenzepine ophthalmic gel in children with myopia: a 1-year, multicenter, double-masked, placebo-controlled parallel study. Arch Ophthalmol 2004;122:1667-74. 10) Siatkowski RM, Cotter SA, Crockett RS, et al. Two-year multicenter, randomized, double-masked, placebo-controlled parallel safety and efficacy study of 2% pirenzepine ophthalmic gel in children with myopia. J AAPOS 2008;12:332-9. 11) Adler D, Millodot M. The possible effect of under correction on myoic progression in children. Clin Exp Optom 2006;89:315-21. 12) Katz J, Schein OD, Levy B, et al. A randomized trial of rigid gas permeable contact lenses to reduce progression of children's myopia. Am J Ophthalmol 2003;136:82-90. 13) Walline JJ, Jones LA, Mutti DO, Zadnik K. A randomized trial of the effects of rigid contact lenses on myopia progression. Arch Ophthalmol 2004;122:1760-9. 14) Cheung SW, Cho P, Fan D. Asymmetrical increase in axial length in the two eyes of a monocular orthokeratology patient. Optom Vis Sci 2004;81:653-6. 15) Charman WN, Mountford J, Atchison DA, Markwell EL. Peripheral refraction in orthokeratology patients. Optom Vis Sci 2006;83:641-8. www.ophthalmology.org 1273
- 대한안과학회지 2011 년제 52 권제 11 호 - =ABSTRACT= The Inhibitory Effect of Myopic and Astigmatic Progression by Orthokeratology Lens Won Hee Lee, MD, PhD 1, Young Kee Park, MD, PhD 1, Jong Mo Seo, MD, PhD 2,3, Jong Hoon Shin, MD 4 Lee and Park s Eye Clinic 1, Seoul, Korea Department of Electrical Engineering, College of Engineering, Seoul National University 2, Seoul, Korea Department of Ophthalmology, Seoul National University Hospital 3, Seoul, Korea Department of Ophthalmology, Pusan National University School of Medicine 4, Busan, Korea Purpose: To investigate the clinical effects of orthokeratology lens wear on inhibition of the progression of Korean myopia and astigmatism. Methods: The authors reviewed out-patient records of 144 eyes of 74 patients wearing orthokeratology lenses. The cycloplegic refraction and keratometry before and after wearing the lens were compared. The 190 eyes wearing spectacles were included into the control group. We evaluated the relationship between orthokeratology lens wear and control group according to age, initial myopia, initial astigmatism, myopic progression, astigmatic progression and duration of orthokeratology lens wearing. Results: The mean cycloplegic refractive error of spherical equivalent was -3.36 ± 1.96 diopters (D) in the patients wearing orthokeratology lenses, the mean astigmatism was -0.86 ± 0.72 D, and the mean wearing period was 3.41 ± 1.5 years. The mean myopic progression was 0.25 ± 0.31 D in lens wearing, and 0.62 ± 0.39 D in glasses wearing, respectively. There were statistically significant differences between lens and glasses wearing group (t-test, p < 0.01). The mean astigmatic progression was 0.06 ± 0.22 D in lens wearing, and 0.15 ± 0.21 D in glasses wearing control group respectively, and the results also show statistically significant differences (t-test, p < 0.01). There were no relationships between two groups as for age, initial myopia, initial astigmatism and duration of orthokeratology lens wearing Conclusions: The orthokeratology lens was found to be effective in suppression of the progression of Korean myopia and astigmatism, compared with the glasses. J Korean Ophthalmol Soc 2011;52(11):1269-1274 Key Words: Astigmatism, Myopia, Orthokeratology Address reprint requests to Won Hee Lee, MD, PhD Lee and Park s Eye Clinic #184-10 Jamsil-dong, Songpa-gu, Seoul 138-220, Korea Tel: 82-2-423-2277, Fax: 82-2-423-2274, E-mail: leeeye47@hanmail.net 1274 www.ophthalmology.org