ISSN(print) 1226-5012 21(3):191-201, September 2016 < 초청논문 > http://dx.doi.org/10.14479/jkoos.2016.21.3.191 The Effect of Artificial Tear Components on Tear Film Stability of Dry Eyes in the Early Stage of Soft Contact Lenses Wear So Ra Kim, Jung A Lim, Ji Hye Jung, Hyun Young Byun, and Mijung Park* Dept. of Optometry, Seoul National University of Science and Technology, Seoul 01811, Korea (Received May 10, 2016: Revised August 17, 2016: Accepted September 7, 2016) Purpose: In the present study, the effect of artificial tears with different ingredients on tear film stability and subjective symptoms of dry eyes in the early stage of soft contact lenses wear was investigated. Methods: The three kinds of artificial tears and saline solution were respectively applied onto 50 dry eyes which wore soft contact lenses made of etafilcon A. Then, non-invasive tear film break-up time (NIBUT) was measured at every five minutes for 30 minutes right after the of artificial tears, and the changes in blink rate and subjective symptoms were estimated after 30 minutes from the s. Results: All three kinds of artificial tears increased NIBUT larger than saline. The effect of increasing NIBUT immediately after the of artificial tears was the largest when the artificial tear containing viscosity enhancer was used. The duration time of the effect was the longest when the artificial tear having both surfactant and viscosity enhancer was applied. The blink rate was not significantly changed when both artificial tears and saline solution were instilled. Subjective symptoms were significantly improved by the of both artificial tears and saline solution and dryness, irritation, tiredness, stiffness, dazzling were improved by the use of most solutions. However, the subjective symptoms were rebounded to the level before the of artificial tears after 30 minute-. Conclusions: It was revealed that both artificial tears and saline solution could improve the subjective symptoms of dry eye in the early stage of soft contac lenses however, the effect of these solutions on the tear film stability was different according to the components. From the results, it is suggested that the proper selection of artificial tears is necessary for the improvement of dry eye symptoms at the early stage of soft contact lenses wear in dry eye. Key words: Artificial tear, Dry eyes, Soft contact lens, Non-invasive tear film break-up time, Blink rate, Subjective symptoms 서론콘택트렌즈는각막에직접접촉되기때문에관리를조금만소홀히해도심각한부작용을초래할수있다. 최근연구에따르면안과에내원한콘택트렌즈합병증환자들의주요질환은각막미란, 비감염성각막침윤, 알러지질환, 결막충혈, 감염성각막궤양, 안구건조증이라고보고된바있다. [1] 또한대학생을대상으로한설문조사에의하면콘택트렌즈착용자중 54.9% 가콘택트렌즈부작용을경험한적이있다고응답하였고부작용의종류는안구건조증이 35%, 결막염이 34%, 각막염이 12.5% 로안구건조증을가장많이경험한것으로나타났다. [2] 이러한안구건조증은최근 10-30대사이에서스마트폰, 태블릿 PC와같은휴대용기기와컴퓨터의과도한사용과도밀접한영향이있는것으로알려져있다. 즉, 전자매체를오래사용하다보면눈깜박임횟수가줄어들고눈물이증발되기쉬워져안구건조증이유발하게된다. [3,4] 안구건조증은또한안구표면에상처와염증을동반하면서건조증이더욱심화되는악순환을반복하게된다. 이러한경우콘택트렌즈를착용하면기계적인마찰에의해각막미란이나각막염의발생률이더증가할가능성이있다. 따라서콘택트렌즈의착용에있어안구건조증은지속적인관심과치료가필요하다. 건성안의예방또는치료를위해인공눈물, 안연고, 눈물의배출을막는누점마개의사용, 자가혈청점안액, 사이클로스포린점안액등이사용된다. [5] 실제로콘택트렌즈 *Corresponding author: Mijung Park, TEL: +82-2-970-6228, E-mail: mjpark@seoultech.ac.kr 본논문의일부내용은 2016년도한국안광학회하계학술대회에서구연으로발표되었음. 191
192 So Ra Kim, Jung A Lim, Ji Hye Jung, Hyun Young Byun, and Mijung Park 착용건성안환자들은상대적으로쉽게구입할수있고간편하게사용할수있는인공눈물을가장많이사용하게된다. 인공눈물은안구표면의윤활작용을개선하고수분을공급하는치료방법으로시중에판매되는인공눈물은제품에따라습윤제, 계면활성제, 점성조절제, 보존제, 완충제, 삼투압유지제등이선택적으로첨가되며건성안의예방및치료를목적으로첨가되는성분은습윤제, 계면활성제, 점성조절제이다. 습윤제로사용되는성분은 polyvinyl alcohol 및 polyvinyl pyrrolidone 등이있으며, 점성조절제로사용되는성분은쓰인 carboxymethylcellulose sodium (CMC), hydroxyethyl cellulose (HEC) 및 hydroxypropyl cellulose와같은 cellulose 계열과 hyaluronic acid 등으로인공눈물이각막에머무르는시간을늘려주는역할을하며, 계면활성제로사용되는성분은 polysorbate 및 poloxamer 등으로자극완화제와유화억제제로서뿐만아니라상피세포의투과도를높여다른물질들의투과가용이하게하는역할도같이하게된다. [6-10] 본연구에서는각각다른성분으로이루어진인공눈물들이건성안에어느정도효과가있으며성분별로어떤차이가있는지를알아보기위하여식염수, 주성분이계면활성제인인공눈물, 점성조절제인인공눈물, 계면활성제와점성조절제가모두함유되어있는인공눈물이 NIBUT 및순목횟수에미치는영향을알아보고자각증상개선효과를비교분석하였다. 대상및방법 1. 연구대상안질환이없고시력교정술을받지않은대학생 (20.2±1.34 세, 18~23세 ) 25명 50안을대상으로하였다. 실험대상안은건성안만을대상으로하였고건성안은 NIBUT 10초미만을기준으로판정하였다. 2. 소프트콘택트렌즈와인공눈물 Etafilcon A재질소프트콘택트렌즈 (Acuvue, USA) 를사용하였다 (Table 1). [11] 인공눈물은주성분으로계면활성제만함유되어있는용액 (Solution A), 점성조절제만함유되어있는용액 (Solution B), 계면활성제와점성조절제가같이함유되어있는용액 (Solution C) 을사용하였으며, 식염수를대조군으로하여효과를비교하였다 (Table 2). [12] 인공눈물점안양은한방울이었다. Table 1. The specification of tested soft contact lenses provided by the manufacturer Manufacturer Johnson & Johnson Vision Care Brand name 1day ACUVE USAN etafilcon A Monomer HEMA, methacrylic acid Replacing schedule 1 day Base curve(mm) 8.5 Total diameter(mm) 14.2 Water content(%) 58 Center thickness(mm) 0.084 Refractive power(d) 3.00 Dk/T((cmxmL)/(sxmLxmmHg)) a 33 HEMA: Hydroxyethyl methacrylate; MAA: Methacrylic acid a Manufacturer-reported values Table 2. The composition of tested artificial tears Classification Saline solution Solution with surfactant (Solution A) Solution with viscosity enhancer (Solution B) Solution with viscosity enhancer and surfactant (Solution C) Artificial tear solution Isotonic sodium chloride solution Eyedew ophthalmic solution Prenz eye angel mild eye drops Prenz eye drop's solution Manufacture Ingredients Usage Daihan Pharmaceutical Corporation Choongwae Shin-yak Corporation JW Pharmaceutical Corporation JW Pharmaceutical Corporation Sodium chloride 0.18 g, 20% PHMB 0.05 µm of 20 ml - Polysorbate80 10 mg, sodium chloride, retinyl palmitate, disodium edetate hydrate, sodium citrate hydrate, citric acid, D- mannitol, sodium hydroxide, water for injection of 1mL Sodium carboxymethyl cellulose(cmc) 5 mg, sodium chloride, calcium chloride hydrate, potassium chloride, magnesium chloride hydrate, sodium lactate solution, sodium hydroxide, hydrochloric acid, water for injection of 1 ml Sodium chloride 5.5 mg, potassium chloride 1.5 mg, glucose 0.05 mg, boric acid 5 mg, borax 0.45 mg, hydroxyethyl cellulose 1 mg, disodium edetate hydrate 0.1 mg, polysorbate80 1.5 µl, chlorhexidine gluconate solution 0.25 µm, chlorhexidine gluconate 0.05 mg, water for injection of 1 ml 1 to 2 drops per 1time 1 to 2 drops per 1time 2 to 3 drops per 1time
The Effect of Artificial Tear Components on Tear Film Stability of Dry Eyes in the Early Stage of Soft Contact Lenses Wear 193 3. NIBUT 측정및순목횟수측정케라토미터 (OM-4, TOPCON, Japan) 로관찰했을때각막반사상인 3개의마이어상이찌그러지는순간을측정하여 NIBUT로하였다. NIBUT는콘택트렌즈착용전, 콘택트렌즈를 30분간착용한후와인공눈물을점안한직후, 5 분, 10분, 15분, 20분, 25분, 30분후에측정하였다. 모든경우에서 3회측정후평균값을 NIBUT값으로하였다. [13] 순목횟수는피검자가자각하지않은상태에서측정하였으며눈을깜박이는횟수를 1분동안측정하여순목횟수로하였다. 순목횟수는나안, 콘택트렌즈를 30분간착용한후, 인공눈물을점안한직후, 인공눈물을점안한 30분후각각측정하였다. [14] Fig. 1. NIBUT of dry eyes before and after soft contact lenses wear. * Significantly different from each group at p<0.05 4. 자각적증상평가피검자가느끼는자각적불편감을측정하였다. 콘택트렌즈를착용한직후에발생할수있는반사적인눈물분비및이물감이제거된상태에서의눈의상태를평가하기위해서콘택트렌즈를 30분간착용한후에측정하였으며, [15] 인공눈물의효과를알아보기위해인공눈물을넣은직후와 30분후자각적증상평가를실시하였다. 평가항목은건조감, 이물감, 피곤감, 작열감, 뻑뻑함, 따가움, 가려움, 눈시림, 충혈이었으며 5점척도로평가하였다. 5. 통계처리실험결과는 SPSS V.22의통계프로그램을사용하여인공눈물용액에의한 NIBUT, 순목횟수, 자각적증상에변화량의평균값과상관성값을산출하여유의수준은 p<0.05로하였다. NIBUT는 t-test, 반복측정 ANOVA test로분석하였고, 순목횟수는 t-test, ANOVA test로분석하였으며, 자각적증상평가는 t-test, 대응표본 t-test로분석하였다. 결과및고찰 1. NIBUT 변화콘택트렌즈착용전의 NIBUT는 6.87±1.2초이고, 콘택트렌즈착용후의 NIBUT는 5.43±1.1초이었다 (Fig. 1). 콘택트렌즈착용전과후의 NIBUT값을대응표본 t-test로분석하였을때, 유의수준이 으로통계적으로유의하였다. 실험대상을건성안으로하였기때문에콘택트렌즈착용전에 NIBUT가 10초미만이었고, 건성안에콘택트렌즈를착용시 NIBUT는더감소하여눈에대한자극이더심해질가능성이큰것으로보인다. 식염수점안으로 NIBUT가 104.7% 상승하는것으로나타났다. 식염수에함유되어있는성분은삼투압을조정하기위한염화나트륨과균오염을방지하기위한보존제이 Fig. 2. NIBUTs before and immediately after of artificial tears. * Significantly different from each group at p<0.05 며대부분의성분은수분이므로이러한식염수의 NIBUT 증가효과는수분의보충으로인해나타나는결과로보인다. 계면활성제인 polysorbate 80을함유하고있는인공눈물인 solution A를점안하였을때는 NIBUT가 138.7% 상승하여계면활성제의작용으로인해수분보충만을하는식염수보다 NIBUT가증가한것으로보인다. 점성조절제인 CMC가포함된 solution B를점안하였을때 NIBUT는콘택트렌즈착용후보다 194.7% 상승하여인공눈물을점안한직후의 NIBUT 상승효과는다른용액들과비교하여가장효과가높은것으로나타났다. 계면활성제와점성조절제가모두포함된 solution C에서는 NIBUT가 187.0% 상승하였다 (Fig. 2). 인공눈물의지속시간을알아보기위해인공눈물을점안한후 5분간격으로 NIBUT를측정하여보았다. 인공눈물점안직후에는 NIBUT가 100% 이상의증가를보였던것에반하여점안 5분후에는 NIBUT가급격하게감소하여인공눈물을점안하기전과비교하여식염수는 25.7%, solution A는 44.4%, solution B는 40.8%, solution C는 54.0% 의상승에그쳤다. 즉, 5분후에도인공눈물의눈물막에미치는효과가어느정도존재하지만점안직후에비해서는크게감소함을확인할수있었다. 식염수는점안
194 So Ra Kim, Jung A Lim, Ji Hye Jung, Hyun Young Byun, and Mijung Park Fig. 3. The change of NIBUT with time after of artificial tears. A. Saline solution, B. Solution A, C. Solution B, D. Solution C Table 3. Statistical analysis of NIBUTs with time after of artificial tears NIBUT(sec) After Artificial tears Before P-value Time(min) 0 5 10 15 20 25 30 Saline solution 5.33±0.99 10.91±4.14 6.70±1.53 5.97±1.26 5.27±0.86 4.88±0.72 4.55±0.66 4.36±0.60 Solution A 5.38±1.05 12.84±3.57 7.77±1.84 6.74±1.21 6.21±1.09 5.58±1.05 5.15±1.05 4.85±0.90 Solution B 5.52±1.08 16.27±7.59 7.77±1.74 6.72±1.54 6.13±1.24 5.66±1.18 5.21±0.81 4.81±0.86 Solution C 5.48±1.09 15.73±5.51 8.44±1.96 7.26±1.60 6.77±1.41 6.07±1.60 5.58±1.35 5.30±1.41 한직후부터점점 NIBUT가감소하여점안 15분후가되었을때콘택트렌즈를착용한후인인공눈물을점안하지않았을때와비슷해졌고, solution A는점안 25분후가되었을때, solution B는점안 20분후가되었을때, solution C는점안 30분후가되었을때점안전과유사한수준으로복귀하였다 (Fig. 3). 식염수를점안하였을때는점안 30 분후, solution B는점안 25분후 NIBUT값이점안전보다감소하였다. Etafilcon A 재질렌즈착용전과착용직후, 착용후 2시간간격으로 NIBUT값변화를측정한 Lakshman 등 [16] 의연구에서 NIBUT가시간경과에따라유의하게감소하는것으로나타났다. 따라서본연구의결과역시콘택트렌즈착용시간이경과함에따라 NIBUT가감소하여나타나는결과로보여진다. 반복측정 ANOVA test를통하여각용액들의시간에따른 NIBUT값변화를통계분석하였을때모든용액이시간이경과함에따라 통계적으로유의하게 NIBUT가감소함을알수있었다 (Table 3). 인공눈물점안시간대별로인공눈물구성성분에따른 NIBUT의차이가통계적으로유의한지를알아보기위해 t-test를실시하였다. Solution A는식염수와의비교에서인공눈물을점안하지않았을때를제외하고모든시간대에서통계적으로유의한차이가있었다. Solution A와 solution B의비교에서인공눈물을점안한직후만이통계적으로유의한차이가있었으며, solution A와 solution C 의비교에서는인공눈물을점안한직후와 15분후의 NIBUT 값이유의한차이가있었다. Solution B는 solution C와의비교에서인공눈물을점안한 15분후와 30분후의 NIBUT 값이유의한차이가있었고, 식염수와의비교에서점안직후와 5분후, 10분후, 15분후, 20분후, 25분후, 30 분후가유의하였다. Solution C는식염수와의 NIBUT 비
The Effect of Artificial Tear Components on Tear Film Stability of Dry Eyes in the Early Stage of Soft Contact Lenses Wear 195 Table 4. Statistical analysis of NIBUTs according to the ingredients of artificial tears Saline solution Solution A Solution B Solution C Comparison Solution A Solution B Solution C Saline solution Solution B Solution C Saline solution Solution A Solution C Saline solution Solution A Solution B Before 0.830 0.379 0.481 0.830 0.515 0.631 0.379 0.515 0.868 0.481 0.631 0.868 P-value After time(min) 0 5 10 15 20 25 30 0.014 0.014 0.005 0.003 0.005 0.685 0.003 0.685 0.991 0.081 0.991 0.071 0.081 0.071 0.009 0.926 0.071 0.009 0.926 0.087 0.071 0.087 0.735 0.028 0.735 0.017 0.017 0.028 0.705 0.073 0.705 0.153 0.073 0.153 0.001 0.001 0.738 0.075 0.738 0.098 0.075 0.098 0.003 0.809 0.063 0.003 0.809 0.040 0.063 0.040 교에서인공눈물을점안하지않았을때를제외하고모두통계적으로유의하였으며, solution A와의비교에서는점안직후와점안 5분후에서유의하였다. 또한 solution B 와의비교에서는점안 15분후, 30분후에서만유의하였다 (Table 4). 이상에서 solution B는점안직후에는 NIBUT값의증가폭이가장컸지만, 지속시간은오히려 solution A 및 solution C보다짧아지는것을알수있었다. 반면, solution C 는점안직후에는비교적큰증가폭을보이고, 점안후 5 분부터인공눈물의지속시간이가장긴것으로나타났다. 식염수는점안직후에가장작은증가폭을보였고점안후 5분부터인공눈물의지속시간도가장짧은것으로나타났다. 2. 순목횟수변화인공눈물점안이순목횟수에미치는영향을알아본결과콘택트렌즈착용전일때의순목횟수는 24±10.7 회이고, 콘택트렌즈착용후일때의순목횟수는 27±8.3 회이었다 (Fig. 4). 콘택트렌즈착용전보다콘택트렌즈착용후에피검자의순목횟수가유의수준이 0.001으로통계적으로유의하게증가하였다. 인공눈물을점안하였을때에식염수는순목횟수의변화가없었으며, solution A는 3.7%, solution B는 3.8%, solution C는 7.4% 의증가를보였다. 인공눈물을점안한직후에는다량의수분증가에의한안검의반사작용으로인해서순목횟수가상승할것이라고예측하였으나, 식염수및인공눈물의점안으로인해순목횟수증가정도가미미하여수분의증가로인한순목횟수의변화정도가 Fig. 4. Blinking rates before and after soft contact lenses wear. * Significantly different from each group at p<0.05 크지않음을알수있었다. 인공눈물을점안하지않았을때에비해서인공눈물을점안한 30분후의순목횟수변화정도는식염수에서 3.6% 감소, solution A에서 3.7% 증가, solution B에서 3.8% 증가이었으며, solution C에서는변화가없었다 (Fig. 5). 순목횟수의증감이인공눈물간에통계적으로유의한차이가나지않아 (data not shown) 순목횟수의변화정도도미미하였기에인공눈물의점안이순목횟수에는큰영향을미치지않는것으로판단된다. One-way ANOVA 및 t-test 검정을통한통계처리결과에서도식염수와인공눈물모두통계적으로유 의한순목횟수의변화를초래하지않은것으로나타나 (data not shown), 인공눈물의점안이순목횟수에는큰영향을미치지않는것을알수있었다. 3. 자각적증상평가식염수를점안하기전과점안직후를비교해보면항목
196 So Ra Kim, Jung A Lim, Ji Hye Jung, Hyun Young Byun, and Mijung Park Fig. 5. The change of blinking rates with time after of artificial tears. A. Saline solution, B. Solution A, C. Solution B, D. Solution C Fig. 6. Subjective symptom score according to the use of artificial tears. A. Saline solution, B. Solution A, C. Solution B, D. Solution C * Significantly different from each group at p<0.05 중건조감, 이물감, 뻑뻑함, 가려움, 눈시림이통계적으로유의한차이를보였고, 식염수를점안한 30분후에는이러한자각증상개선효과가모두없어졌다. 식염수점안직후에비해점안 30분후에는건조감, 이물감, 피곤감, 뻑뻑함, 가려움이통계적으로유의하게악화되어점안전과유사한자각증상정도를보였다 (Fig. 6A, Table 5). Solution A에서인공눈물을점안하기전과점안직후를비교해보면건조감, 이물감, 작열감, 뻑뻑함이통계적으로유의한차이를보였고, 인공눈물을점안한 30분후에는이러한자각증상개선효과가모두없어졌다. Solution A 점안직후에비해점안 30분후에는건조감, 이물감, 피곤감, 뻑뻑함이통계적으로유의하게악화되어점안전과유사한자각
The Effect of Artificial Tear Components on Tear Film Stability of Dry Eyes in the Early Stage of Soft Contact Lenses Wear 197 Table 5. Statistical analysis of each subjective symptom according to artificial tears Solution Saline solution Solution A Solution B Solution C Before Comparison Immediately after 30 minutes after Immediately after 30 minutes after Before Immediately after 30 minutes after Immediately after 30 minutes after Before Immediately after 30 minutes after Immediately after 30 minutes after Before Immediately after 30 minutes after Immediately after 30 minutes after P-value Dryness Irritating Tiredness Burning Stiffness Sting Itching Dazzling 0.001 0.092 0.110 0.697 0.018 0.049 0.890 0.214 0.530 0.573 0.476 0.646 0.626 0.122 0.024 0.015 0.344 0.001 0.424 0.031 0.545 0.001 0.005 0.067 0.043 0.003 0.416 0.183 0.069 1.000 0.454 0.192 0.394 0.787 0.412 0.089 0.656 0.047 0.004 0.161 0.020 0.185 0.692 0.101 0.161 0.014 0.485 0.003 0.331 0.215 0.014 0.879 0.852 0.190 0.308 0.644 0.083 0.301 0.594 0.111 0.001 0.817 0.485 0.763 0.029 0.015 0.021 0.400 0.019 0.817 0.250 0.040 0.776 1.000 0.690 0.646 0.679 0.308 0.616 0.534 0.015 0.005 0.676 0.005 0.485 0.513 0.114 증상정도를보였다 (Fig. 6B, Table 5). Solution B를점안하기전과점안직후를비교해보면건조감, 피곤감, 뻑뻑함, 눈시림이통계적으로유의한차이를보였고, 인공눈물을점안한 30분후에는이러한자각증상개선효과가모두없어졌다. Solution B 점안직후에비해점안 30분후에는건조감, 피곤감, 뻑뻑함, 눈시림이통계적으로유의하게악화되어점안전과유사한자각증상정도를보였다 (Fig. 6C, Table 5). Solution C를점안하기전과점안한직후를비교해보면건조감, 이물감, 피곤감, 뻑뻑함, 눈시림이통계적으로유의한차이를보였고, 인공눈물을점안한 30분후에는이러한자각증상개선효과가모두없어졌다. Solution C 점안직후에비해점안 30분후에는건조감, 이물감, 피곤감, 뻑뻑함이통계적으로유의하게악화되어점안전과유사한자각증상정도를보였다 (Fig. 6D, Table 5). 충혈은모든조건에서나타나지않았다. 대응표본 t-test를실시하여인공눈물점안전과점안직후의전체적인자각증상의변화를분석한결과, 인공눈물뿐만아니라식염수에서도모두통계적으로유의한차이를보였다. 인공눈물을점안한직후와 30분후에서의자 각증상차이가모든용액에서통계적으로유의하게나타났다. 그러나, 인공눈물점안전과점안 30분후에서의피검사자가느끼는자각증상의차이는통계적으로유의한차이가나지않아눈물막안정화효과가소멸됨을알수있었다 (Table 6). 본연구에서는건성안을대상으로인공눈물의효과를알아보았다. 눈물층은지질층, 수층, 점액층으로구성되어있다. 지질층은눈물층의가장바깥에위치하고메이봄선에서분비되는얇은유층이며, 눈물층표면의형태를매끄럽게유지시켜주고수층의증발을막는데도움을준다. 수층은눈물층의 90% 이상을차지하고각막에필요한영양분과산소를운반한다. 또한상피조직의찌꺼기와독성물질등안구의이물질을제거하는기능이있다. 점액층은각막상피에가깝게위치한층으로서눈물이전체안구표면을덮도록하며특히수층이골고루퍼지도록하여안구표면에보습력을향상시키도록하는층이다. [17-21] 이러한눈물층들이정상적으로분비되어야눈물막의안정성이유지되게되며분비에문제가발생하였을때건성안이발생하게된다. 본연구에서는수분보충과눈물막안정성
198 So Ra Kim, Jung A Lim, Ji Hye Jung, Hyun Young Byun, and Mijung Park Table 6. Statistical analysis of total subjective symptom according to the ingredients of artificial tears by paired t-test P-value Comparison Saline solution Solution A Solution B Solution C Immediately after Before 30 minutes after 0.102 0.562 0.463 0.864 Immediately after 30 minutes after 유지를위해점안하는계면활성제또는점성조절제가주성분인인공눈물을대상으로눈물막안정성을평가하였다. 눈물막안정성평가는건성안을분류하는기준으로사용되며, 많은연구에서눈물막안정성평가를위해사용되고있는방법인 NIBUT 측정을통하여실시하였다. [13,16] 또한, 눈물막이파괴되면눈물의분포를위해더빈번하게일어나게되는순목의횟수를측정하여, [14] 인공눈물의눈물막안정성에미치는효과를알아봄과동시에눈꺼풀의마찰에계면활성제나점성조절제가상반된영향을미치게되므로이에대한영향을같이알아보고자하여인공눈물점안후의순목횟수를측정하였다. 본연구에서구성성분조성이다른인공눈물을점안한후 NIBUT를비교해보았을때점성조절제와계면활성제가모두포함된 solution C의경우점안직후부터 30분후까지가장오랫동안효과가유지된것으로나타났다. 점성조절제만포함된 solution B의경우점안직후에는 NIBUT가가장높았으나그후로계속감소하다가점안 20분후에는점안전과비슷한수치를보여식염수다음으로유지속도가짧은양상을보였다. 인공눈물에함유된점성조절제의분자량이정확하지않아용액속의농도를정확하게알수없지만농도의차이에의해인공눈물간효력의차이가나타났을가능성을배제할수없다. 계면활성제만포함된 solution A의경우는점안직후의 NIBUT 가식염수다음으로짧았지만 5분후부터는점성조절제와계면활성제가모두포함된 solution C 다음으로높게나타났다. 이상의결과로미루어보아인공눈물에함유된성분에따라효력의발현정도나지속시간에차이가있는것을알수있었다. 점성조절제와계면활성제가모두포함된 solution C의성분은 HEC(hydroxyethyl cellulose) 와 polysorbate 80이며점성조절제만포함된 solution B는 CMC, 계면활성제만포함된 solution A는 polysorbate 80이첨가되었다. HEC와 CMC는모두셀룰로오스의유도체로서인공눈물의점도를상승시키기위하여사용되며, 자연적인눈물과비슷한굴절률을가지고있으며 ph가안정적이기때문에인공눈물에많이사용된다. 이러한인공눈물에함유되어있는셀룰로오스유도체는낮은분자량때문에각막상피에쉽게 스며들어수분부족형건성안에효과적으로사용된다. [22] 본연구에서와같은계면활성제 polysorbate 80이눈물막안정성에미치는효과는안구표면에서점액층과지질층의표면장력을낮춰주기때문인것으로보이며, 인공눈물에함유된계면활성제성분에의한눈물막안정화효과는증발성건성안에도효과적일것으로보인다. [23] 인공눈물점안으로인한순목횟수의변화는다소증가하는경향을보였으나통계적으로유의하지않은변화였으며, 구성성분의조성이다른인공눈물이나식염수모두에서큰차이가없는것으로보아순목횟수의증가경향은안구표면에용액이들어감에따라안검이반사적으로깜빡이게되는효과일가능성이큰것으로보인다. 순목횟수는반복적으로건조된소프트콘택트렌즈를착용하였을때나 [24] 일일착용렌즈를초과착용하였을때크게증가하는것 [25] 으로보고된바있다. 따라서본연구에서인공눈물이순목횟수에미치는효과가미미한것은콘택트렌즈를착용한초기에점안되어콘택트렌즈의건조로인한자극감이나렌즈형태변화가크지않아나타나는결과로보이며, 건성안이지속적으로콘택트렌즈를착용하였을때는인공눈물의효과가다른양상으로나올가능성이있을것으로보인다. 또한, 계면활성제의경우순목시안검과각막과의마찰을약화시킬수있고점성조절제의경우는오히려마찰을강화시킬수있으나인공눈물점안으로인해순목횟수의차이가크게나타나지않는것으로보아안검과각막과의마찰에대한작용은미약한것으로판단되었다. 자각증상은인공눈물점안전과점안직후, 점안직후와 30분후에건조감, 이물감, 피곤감, 뻑뻑함, 눈시림항목에서유의한차이를보였다. 하지만점안전과점안 30분후의자각증상에는모든용액에서유의성이존재하지않았는데이는점안 30분후에는인공눈물이대부분흡수또는증발되어피검사자의안구표면이다시건조해진다고볼수있다. 건성안의경우는착용하고있는소프트콘택트렌즈의마름이지속적으로반복될수밖에없다. 소프트콘택트렌즈가마르게되면전체직경및곡률반경이변하게되며이러한콘택트렌즈의변화는피팅상태의변화를초래하게되며결과적으로불편감을초래할수밖에없다. [24,26]
The Effect of Artificial Tear Components on Tear Film Stability of Dry Eyes in the Early Stage of Soft Contact Lenses Wear 199 본연구에서는수분과수분유지력을증가시킬수있는점성조절제가포함된인공눈물과증발억제효과가있는계면활성제가포함된인공눈물을점안하여그효과를비교해보았으며, 수분만을보충하는식염수에비해이러한점성조절제또는계면활성제가함유된인공눈물의눈물막안정성효과가더우수하며성분조성에따라효력에차이가있음을밝혔다. 그러나실험에사용된용액모두지속효과가 30분을넘기지못하였기때문에인공눈물사용시한번점안으로는꾸준한효과를기대할수없고일정시간간격으로자주점안해주어야할것으로보인다. 본연구에서는시중에서점안액으로사용되고있는인공눈물의눈물막안정성에미치는효과에대해알아보았다. 인공눈물에는눈물막안정성에영향을미치는점성조절제와계면활성제이외에도다른효과및작용을위해포함된성분들이포함되어있다. 즉, 삼투압조절을위한염, 균의증식을억제하기위한보존제, ph를조절하기위한완충제, 안정화제등이함유되어있다. 본연구에서나타난눈물막안정성효과가이들성분과점성조절제및계면활성제의상호작용에의해영향을받았을가능성도있다고보여진다. 그러나제조사에서눈물막안정성을위해주성분으로사용한것은점성조절제및계면활성제이며눈물막안정성에대한작용은이두가지종류의성분에의해크게영향을받을수밖에없다. 따라서본연구에서는점성조절제와계면활성제의효능비교에초점을맞추어연구를진행하였으며실제임상에서적절하게사용될수있는조정에대한의미있는결과를도출하였다. 추후인공눈물성분의조성을조절한용액에대한연구가추가로수행된다면점성조절제및계면활성제성분자체에대한효능비교까지이루어질수있으리라보인다. 결론본연구에서는건성안이소프트콘택트렌즈착용초기에함유성분이상이한인공눈물을점안하였을때 NIBUT, 순목횟수, 자각적증상에미치는영향을평가하여보았다. 3종의인공눈물용액모두식염수보다 NIBUT 값의증가에효과적이었다. 인공눈물을점안하기전과비교하여점안직후에서점성조절제가포함된인공눈물을점안하였을때 NIBUT 증가효과가가장컸으며, 인공눈물의지속효과는계면활성제와점성조절제가모두포함된인공눈물을점안하였을때지속효과가가장컸다. 계면활성제만포함된인공눈물과점성조절제만포함된인공눈물은안구표면의수분을유지하는시간을늘려주기는하지만그효과가 20~25분이상을지속하지못하였다. 3종의인공눈물모두점안 30분후에는효력이감소되어원상복귀를보이 는것으로나타났다. 순목횟수는인공눈물을점안한직후에는약간상승하는경향을보였지만, 통계적으로유의하지않는미미한변화였다. 자각증상은인공눈물및식염수점안으로점안직후에는모두통계적으로유의하게향상되었으며대부분건조감, 이물감, 피곤감, 뻑뻑함, 눈시림에증상의향상이나타났다. 점안 30분후에는이러한자각증상의개선효과는없어져인공눈물점안전의자각증상과유사한수준으로복귀하였다. 인공눈물의효과는함유성분에따라눈물막안정성측면에서달라질수있음을본연구를통하여알수있었다. 건성안에점성조절제와계면활성제가모두포함된인공눈물의효과가가장오래지속되는것으로보아계면활성제와점성조절제가모두첨가된인공눈물이건성안의안구건조증개선에더도움이될것으로보인다. 감사의글 본연구는 2016년도서울과학기술대학교교내학술연구비로수행되었습니다. REFERENCES [1] Kim JH, Song JS, Hyon JY, Chung SK, Kim TJ. A survey of contact lens-related complications in Korea: the Korean contact lens study society. J Korean Ophthalmol Soc. 2014;55(1):20-31. [2] Kim TH, Min GR, Sung AY. Study on the contact lenses wear status of university students. J Korean Ophthalmic Opt Soc. 2005;10(2):151-157. [3] Kim JS, Cho KJ, Song JS. Influences of computer works on blink rate and ocular dryness in adolescents. J Korean Ophthalmol Soc. 2007;48(11):1466-1472. [4] Kim DJ, Cha JW, Park MC, Lee WJ. The influence of temperature and relative humidity variation on the dry eye for using smart phone. J Korean Vis Sci. 2014;16(3):397-407. [5] Kim WJ, Kim HS, Kim MS. Current trends in the recognition and treatment of dry eye: A survey of ophthalmologists. J Korean Ophthalmol Soc. 2007;48(12):1614-1622. [6] Calonge M. The treatment of dry eye. Surv Ophthalmol. 2001;45(2):S227-S239. [7] Kim EC, Joo CK. Efficacy of vitamin A-containing lubricant in dry eye syndrome evaluated by impression cytology. J Korean Ophthalmol Soc. 2008;49(11):1729-1736. [8] Kim EC, Choi JS, Joo CK. A comparison of vitamin A and cyclosporine A 0.05% eye drops for treatment of dry eye syndrome. Am J Ophthalmol. 2009;147(2):206-213. [9] Jang SR, Yun IS, Lim HS, Kook KH. Comparison of wettability for ocular prosthesis depending on different kinds of artificial tear eye drops. J Korean Ophthalmol Soc.
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The Effect of Artificial Tear Components on Tear Film Stability of Dry Eyes in the Early Stage of Soft Contact Lenses Wear 201 소프트콘택트렌즈를착용한건성안의착용초기눈물막안정성에인공눈물성분조성이미치는영향 김소라, 임정아, 정지혜, 변현영, 박미정 * 서울과학기술대학교안경광학과, 서울 01811 투고일 (2016 년 5 월 10 일 ), 수정일 (2016 년 8 월 17 일 ), 게재확정일 (2016 년 9 월 7 일 ) 목적 : 성분조성이다른인공눈물들이소프트콘택트렌즈를착용한건성안의착용초기눈물막안정성및자각증상에미치는영향을알아보았다. 방법 : Etafilcon A 재질의소프트콘택트렌즈를착용한 50 안의건성안에성분조성이다른 3 종의인공눈물용액및식염수를각각점안하고비침습성눈물막파괴시간 (NIBUT) 를인공눈물점안한직후부터 30 분까지 5 분간격으로측정하였고, 점안 30 분후의순목횟수및자각증상변화를알아보았다. 결과 : 3 종의인공눈물모두식염수보다 NIBUT 를더크게증가시켰다. 인공눈물점안직후의 NIBUT 증가효과는점성조절제가포함된인공눈물에서가장컸으며, 효과지속시간은계면활성제와점성조절제가모두포함된인공눈물이가장길었다. 순목횟수는인공눈물용액과식염수점안시모두통계적으로유의한변화가없었다. 자각적증상은인공눈물및식염수점안으로모두통계적으로유의하게향상되었으며대부분의용액에의해건조감, 이물감, 피곤감, 뻑뻑함, 눈시림증상의향상이나타났다. 점안 30 분후에는인공눈물점안전의자각증상과유사한수준으로복귀하였다. 결론 : 건성안의소프트콘택트렌즈착용초기자각증상은인공눈물과식염수모두완화시켜주지만눈물막의안정성에미치는효과는함유성분에따라차이가있음을밝혔다. 본연구결과를통하여콘택트렌즈착용건성안의착용초기안구건조증개선을위해서는적절한인공눈물의선택이필요함을제안한다. 주제어 : 인공눈물, 건성안, 소프트콘택트렌즈, 비침습성눈물막파괴시간, 순목횟수, 자각증상