景深对超声乳化术后假晶状体眼伪调节的影响

目的探讨白内障超声乳化术后假晶状体眼的景深对伪调节的影响。方法白内障患者30例（60眼），年龄（62.77±5.27）岁（50-70岁），其中44眼为假晶状体眼。测量屈光状态、调节幅度、瞳孔直径。睫状肌麻痹后，分别在不矫正散光和配戴人工瞳孔镜片（直径2.5mm）情况下测量单眼调节幅度。采用SPSS11.0统计软件行统计学分析。结果假晶状体眼的移近法单眼调节幅度为（2.35±1.14）D。散光和人工瞳孔对调节幅度的影响分别为0.21D和0.16D。调节前、后瞳孔直径分别为（4.52±0.66）mm和（2.72±0.64）mm。单眼调节幅度与调节前后瞳孔直径变化无相关性（r=0.164，P=0.305）。睫状肌麻痹时不矫正散光和配戴人工瞳孔镜片的单眼调节幅度分别为（0.61±0.18）D和（0.77±0.14）D。结论对于白内障超声乳化术后的假晶状体眼，瞳孔和单纯近视散光所致景深是伪调节的产生机制之一，但不是主要机制。增大景深不是改善伪调节的主要方法，今后还需要从人工晶状体本身的设计或在眼内的位置变化等方面来研究伪调节的机制和相应的改善方案。

Effect of depth of field on pseudoaccommodation after phacoemulsification and implantation of a posterior chamber intraocular lens

Objective To study the relationship between depth of field and pseudoaccommodation in pseudophakia after phacoemulsifi-cation and implantation of a posterior chamber intraocular lens （IOL）. Methods This study was based on measurements of 60 eyes of 30 patients aged 50 to 70 years （mean age 62.77±5.27 years） who had undergone phacoemulsification and implantation of a posterior chamber IOL. Forty-four pseudophakic patients were also ineluded in the study. Accommodative amplitude, refraetive error, and pupillary diameter were measured. Monocular accommodative ampli- tude was also measured under eyeloplegia with astigmatism uncor- rected and with an artificial pupil lens （2.5 mm in diameter）. All data were analyzed with the SPSS11.0 for Windows. Results In pseudophakia, the monocular accommodative amplitude was （2.35±1.14）D. Astigmatism and artificial-pupil induced monocular accommodative amplitude were 0.21 D and 0.16 D, respectively. The diameter of the pupil before and after accommodation was （4.52±0.66）mm and （2.72±0.64）mm, respectively. No correlation was found between monocular accommodative amplitude and the change in pupil diameter before and after accommodation （r=0.164, P=0.305）. Monocular accommodative amplitude measured under cycloplegia with astigmatism uncorrected and an artificial pupil lens was （0.61±0.18）D and （0.77±0.14）D, respectively. Conclusion Depth of field resulting from the pupil and single myopic astigmatism is one fac- tor, but not the key factor, of the mechanism of pseudoaceommodation in pseudophakia after phaeoemulsification and implantation of a posterior chamber IOL. Increasing depth of field is not an effective way to improve pseudoaecommodation.