利用残余调节客观测量方法研究美多丽P对近视儿童睫状肌麻痹的效果

目的通过客观法测量眼残余调节（RA）量,评估美多丽P（质量分数0.5%托品酰胺＋质量分数0.5%苯肾上腺素）在近视儿童中的睫状肌麻痹效果。方法 85例近视儿童,年龄6～14岁;主觉等效球镜-0.75～-5.75D。受试者双眼点用美多丽P滴眼液3次,每次1滴,间隔5min;第3次点用30min后,应用开放视野的红外自动验光仪分别测量单眼注视4m与33cm处0.2SnellenE视标的调节反应。远距离与近距离的调节反应均值之差为RA量。结果平均RA量右眼为（0.22±0.27）D（95%CI：0.16～0.28）,左眼为（0.24±0.27）D（95%CI：0.18～0.30）。RA量在左右眼间（t=-0.84,P=0.41）和不同性别的同眼别间差异均无统计学意义（右眼：t=0.02,P=0.98;左眼：t=-0.82,P=0.41）;应用美多丽P滴眼液后左右眼的RA量呈正相关（r=0.49,P=0.00）;应用美多丽P滴眼液后眼RA量与年龄、近视度数之间均无相关性（r=0.10,P=0.39;r=-0.15,P=0.17）。结论大多数受试者低度的RA量表明,美多丽P滴眼液在近视儿童中是一种有效的睫状肌麻痹剂。

Evaluation of cycloplegy effectiveness of Mydrin-P in myopic children by objective measurement of residual accommodation

Background Tropicamide has been reported to provide an insufficient level of cycloplegia for refractive measurement,especially in children.However,this conclusion mainly originate from subjective assessments of accommodation.So many confounding factors may lead to overestimated results.Objective Purpose of this study was to evaluate the cycloplegic effect of Mydrin-P （0.5% tropicamide and 0.5% phenylephrine） in myopic children by objective measurement.Methods Eighty-five myopic children aged 6-14 years old were recruited in this clinical trial with the subjective spherical equivalent refractive error from-0.75D to-5.75D.Mydrin-P of 40 μL was topically administered to both eyes 3 times at 5-minute interval.At the 30 minutes after the last drop,at least ten accommodative responses to 0.2 Snellen ＂E＂ letters from 4 meters and 33 cm were measured sequentially by monocular fixation using an open-view infrared autorefractometer.All measurements were performed with refractive errors of both eyes,which were determined by noncycloplegic subjective refraction,fully corrected by spectacle lenses.Residual accommodation was calculated as the difference value between the mean accommodative responses （spherical equivalent） obtained at the two distances.Written informed consent was obtained from each child or parents at the initial of this medical procedure.Results The mean residual accommodation was （0.22±0.27）D in the right eye with the 95% confidence interval （CI） 0.16-0.28,and mean residual accommodation of the left eyes was （0.24±0.27）D （95% CI：0.18-0.30）.Seventy-one right eyes （83.5%） and 72 left eyes （84.7%） remained residual accommodation of below 0.50 D.There was no significant difference was found in residual accommodation between the right eyes and left eyes （t=-0.84,P=0.41） or between boys and girls （right eyes：t=0.02,P=0.98;left eyes：t=-0.82,P=0.41）.The Pearson linear analysis revealed the positive correlation in residual accommodation between the right and left eyes （r=0.49,P=0.00）.Regression analysis showed that no significant correlation was found between residual accommodation with age （r=0.10,P=0.39） or degree of myopia （r=-0.15,P=0.17）.Conclusion The low magnitude of residual accommodation indicate that Mydrin-P is an effective and reliable cycloplegic agent for myopic children.