探討針孔測試對臨床視光的新價值

屈光異常，在臨床上是常見的症狀。相較於其他的影響視力因子，屈光異常是一個最容易避免的問題，過去的研究認為可用針孔測試達到最佳屈光異常的矯正，而獲得最佳矯正視力，但是，環境照度對於針孔測試使用時的效應分析，尚有許多不足之處。因此，本研究釐清此議題並尋求針孔篩檢之最佳使用效率。本研究徵求30位受試者，年齡介於20至50歲之間。受試者在亮室(500 lux )與暗室(5 lux )之不同環境照度下進行視敏度之評估測試，並分別使用黑字視標( Black Target )與白字視標( White Target )進行比較，分析結果以student’s T test與Paired-T test進行統計檢定。研究結果發現，使用白字視標在暗室下(5 lux)沒有使用針孔所測得的VA值為0.63 ± 0.20，使用針孔後所測得的VA值為0.81 ± 0.23，前後所測得的相對平均改變量為38.82% ± 48.43 ( p < 0.001)。根據研究的結果經交叉比對分析，証實以針孔測試的方法在暗室白字視標下，可以做為預測是否達到最佳矯正視力的依據，這是針孔測試過去未曾被提出的全新應用價值。

Refraction errors are commonly found in clinical settings and are the most avoidable among all the factors that may affect vision. Previous researches have pointed out that pinhole can be used for the best correction of refraction errors. However, the use of pinhole to achieve best corrected visual acuity (BCVA) has not been extensively studied under different illumination conditions. This study aims to clarify this issue in an effort to achieve the best use of pinhole. A total of 30 volunteers, aged between 20 and 50, were recruited to assess visual acuity under 500 lux or 5 lux conditions, with black target or white target. The results were analyzed with student’s T test and Paired-T test. The average visual acuity achieved with white target under 5 lux was 0.63 ± 0.20 without pinhole, which was increased to 0.81 ± 0.23, showing a relative increase by 8.82% ± 48.43 ( p < 0.001 ). Furthermore, the results indicated that pinhole with white target under 5 lux may be used for prediction of whether BCVA had been achieved by the previous prescription. Thus, a novel use of pinhole was proposed.