• Journal of Korean Ophthalmic Optics Society
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• v.19 no.4
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• pp.527-532
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• 2014

Purpose: The matching of the optical center and the pupil center was measured by photographs in wearing glasses. In this study, the influences of the induced prism by the mismatching are studied. Methods: 74 subjects (148 eyes) who were spectacles wearer were participated in this study. The mean age was $29.19{\pm}12.22$ years (range 19-55 years). The facial photographs of subjects were taken while wearing spectacles. The matching of the corneal reflected image and optical center of the spectacle lens in the horizontal deviations, and the vertical deviations were measured by the observation of the photo image. The prisms induced in accordance with various frame type were calculated from the mismatching deviations. Results: The binocular horizontal deviations were $1.55{\pm}1.70mm$ for the metal frame, $1.71{\pm}2.21mm$ for the clings type plastic frame, and $1.15{\pm}1.38mm$ for the plastic frame. In the horizontal direction induced prism, the ratio over the tolerance was 23%. The ratio were the 17.6% at the BI prism, and 5.4% at the BO prism. The binocular vertical deviation comparisons were $3.93{\pm}1.91mm$ for the metal frame, $5.79{\pm}1.93mm$ for the clings type plastic frame, and 1$6.01{\pm}2.94mm$ for the plastic frame. In the vertical direction induced prism, the ratio over the tolerance was 44.6%. Based on the refraction power, the ratio were 12.2% at -0.25${\leq}-3.00$, and 32.4% at -3.00${\leq}-12.00D$. Conclusions: The induced prisms in the horizontal direction were much in the BI prism. The binocular vertical deviations of the glasses.

• The Korean Journal of Vision Science
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• v.20 no.4
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• pp.443-451
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• 2018

Purpose : To find out the reliability of autorefractometer after laser refractive surgery Methods : We measured and compared spherical and cylinder powers of those undergone LASEK surgery with 1.0 of naked vision after at least 3 months of the surgery with an autorefractometer(CANON Full Auto Ref-Keratometer RK-F1, Japan) and a retinoscope(Streak Retinoscope 18200, WelchAllyn, USA), and also applied spherical equivalent powers. The refractive status before surgery was divided into high, medium, and low myopia according to the results measured using an autorefractometer, and then analyzed again the reliability of the autorefractometer after surgery according to the preoperative refractive status. The agreement of two methods was identified using Bland-Altman(Bland-Altman limits of agreement(LoA)). Results : After the surgery, when comparing spherical, cylinder and equivalent powers in the whole data measured by autorefractometry and retinoscopy significant differences were found(p<0.01). According to the degree of refractive errors, all sort of refractive errors was shown significantly different(p<0.01) except for cylinder power of the medium myopia. In general, the refractive errors especially spherical and spherical equivalent powers by autorefractometry were shown a myopic trend from -0.38 D to -0.53 D. On the other hand, it was shown a hyperopic trend of approximately +0.30 D using retinoscopy. In comparison of two objective refractions, it was shown a myopic trend as $-0.51{\pm}0.45D$(LoA +0.36 D ~ -1.39 D) and compatible. Conclusion : Even though it would be positive in terms of compatibility of the methods, it is necessary that the glasses should be prescribed by subjective refraction since autorefractometry is shown myopic in those undergone the surgery and suffering from myopic regression.