青年人周邊屈光狀態於調節下之變化

周邊屈光理論為近年來會影響正視化與屈光發展的概念，調查結果發現，周邊屈光狀態與中心屈光發展相關。中心屈光尚未發展成近視之前，多數眼睛也都是相對周邊近視的狀態，而並不是呈現相對周邊遠視。近距離工作時水晶體會因為調節而改變屈光力，有可能影響周邊屈光的狀態，故本研究要探究調節作用對於周邊屈光產生的影響。 招募對象為18 ~ 30歲間，散光均低於1.00 D，視力正常無斜視並且健康的青年人。最終收案5位男性，14位女性，除其中4位因單眼散光超過1.00 D而僅收案一眼外，共計收案11隻正視眼與23隻近視眼。正視眼 (≥-0.75 D) 組測量其遠距屈光狀態與近距屈光狀態；近視眼 (<-0.75 D) 組測量完遠距屈光狀態後，配戴隱形眼鏡矯正其屈光不正，再次進行遠距屈光狀態及近距屈光狀態的測量。周邊屈光分析角度為中心與偏離視軸10、15、20、25度的方向。測量結果發現調節遠距與近距等價球面相對周邊屈光在N25 (p = 0.001)、N10 (p = 0.033)、T10 (p = 0.034)、T15 (p = 0.001)、T20 (p < 0.0005)、T25 (p < 0.0005)呈現統計上顯著差異，調節後有更多的相對周邊遠視（較少的相對周邊近視）。周邊散光J0在N25 (p < 0.0005)、N20 (p < 0.0005)、N15 (p < 0.0005)、N10 (p < 0.0005)、T15 (p = 0.001)、T20 (p < 0.0005)、T25 (p < 0.0005) 呈現統計上顯著差異，所有角度看近時都有更正的散光J0。雖然觀察到無論等價球面相對周邊屈光或是周邊散光J0，近視眼組調節後改變量有比正視眼組更多的趨勢，但並未呈現統計上的顯著差異。 調節確實會改變周邊屈光的狀態，使用調節會使屈光狀態暴露在相對周邊遠視以及更多的正值J0之下，這些狀態皆與目前研究中可能造成近視進程的理論相似。本研究認為調節即為讓周邊狀態呈現相對遠視的主因，而若未來進行光學矯正來影響周邊屈光進而有控制近視的效果，抵銷調節產生的周邊屈光狀態變化，應為採用光學方式控制近視的重要關鍵。

PurposeTo investigate the changes in relative peripheral refractive error (RPRE) with and without the intervention of accommodation.MethodsThe 19 subjects aged 18 to 30 years participated in this study, including 11 emmetropia eyes (spherical equivalent > -1.00 D) and 23 myopia eyes (SE≤ -1.00 D). Peripheral refractions were analyzed from the central to 25° for the temporal and nasal retina at both distance and near. To quantify the changes in relative peripheral refraction under accommodation, conventional sphero-cylindrical refractive error was converted into power vectors M (spherical equivalent), J0, and J45 for data analysis. ResultsWhen accommodation was used, there was an increasing trend in RPRE(M) for all the angles and significant differences were found at N25 (p = 0.001), N10 (p = 0.033), T10 (p = 0.034), T15 (p = 0.001), T20 (p < 0.0005), T25 (p < 0.0005). For J0, RPRE was also increased, which suggested that it changed from against-the-rule into with-the-rule astigmatism at N25 (p < 0.0005), N20 (p < 0.0005), N15 (p < 0.0005), N10 (p < 0.0005), T15 (p = 0.001), T20 (p < 0.0005), T25 (p < 0.0005).ConclusionThe relative peripheral refractive errors changed under accommodation condition. It shifted from relative myopia to relative hyperopia for the temporal retina, and also from against-the-rule astigmatism to with-the-rule astigmatism. These results may help explain the association between relative peripheral refraction, accommodation and myopia development.