Compare And Research Among Accommodative Lag Measured By Different Means

ObjectiveBy comparing the lag of accommodation measured when the examined eyes were asked to stare at sighting targets of different distances by different methods respectively, analyze the statistically significant differences of results got by Nott dynamic retinoscopy, MEM dynamic retinoscopy and Fused cross cylinder test(FCC test); By studying the relationship of results got by Nott, MEM and FCC method, preliminarily explore the normal range of results measured by different accommodative lag measurements, provide basis for the selection of measurements, comparison of results and assessment of accommodative function in clinical accommodative lag examinations.Methods81college students (162eyes) randomly selected, aged18to25years old, were examined respectively when they stared at the targets at different distances by different accommodative lag measurement after normative optometry.1. The accommodative lag on the right and left eye was measured when the monocular eyes stared at the targets at50cm,40cm,33cm by FCC Method; the accommodative lag was measured when binocular eyes fix on the targets at50cm,40cm,33cm by FCC test;2. The accommodative lag on the right and left eye was measured when the monocular eyes stared at the targets at50cm,40cm,33cm by Nott dynamic retinoscopy and MEM dynamic retinoscopy respectively;3. The data was analyzed by the paired t test, variance analysis and linear regression analysis using SPSS13.0.Result1. There were not statistically significant differences between the accommodative lag of the right eye and the left when accommodative lag was measured at50cm by different methods (Nott:t=-0.684,P=0.496;MEM:r=-1.043,P=0.300;FCC:t=-1.340, P=0.184);2. There were not statistically significant differences between the accommodative lag of the right eye and the left when they fixed on the targets at40cm measured by different methods (Nott:t=-1.000,P=0.320; MEM:t=-1.685,P=0.096; FCC:t=-1.380, P=0.172);3. There were not statistically significant differences between the accommodative lag of the right eye and the left when they fixed on the targets at33cm measured by different methods(Nott:t=-0.323,P=0.748;MEM:t=-1.229,P=0.223;FCC:t=-0.293, P=0.770);4. Statistically significant differences were found when comparing the results of three different distances by the three different measurements of accommodative lag (50cm: F=24.794,P＜0.001;40cm:F=52.883,P＜0.001;33cm:F=69.304,P＜0.001);5.The linear regression equation of the results measured at40cm by Nott and FCC is: Y=0.415+0.381X,r2=0.305;The linear regression equation of the results measured at40cm by MEM and FCC is:Y=0.698+0.600X,r2=0.571;6. There were statistically significant differences between the accommodative lag of the right eye and the binoculus when they fixed on the targets at different distances measured by FCC test(50cm:t=-7.411,P＜0.001;40cm:t=-6.901,P＜0.001;33cm: t=-10.116,P<0.001).ConclusionThe choice of accommodative lag measurements cannot be free and blind in clinical visual functional examinations; Results measured by different measurements should be compared with the corresponding normal ranges in clinical accommodative lag examinations in order to diagnose the condition of patients’ accommodative lag more accurately.