白内障手术切口大小的角膜地形图分析

Corneal topography analysis ofvaried size of wound incision incataract surgery

本文报道75例(75只眼)白内障术前及术后一周、一月、三月及六月的角膜地形图与角膜曲率计检查的随访结果。第一组25例(25只眼)行4.00mm巩膜隧道小切口及超声乳化,植入软性折迭式人工晶体。第二组25例(25只眼)作7.5mm切口,除5例(5只眼)行超声乳化,其余20只眼行现代囊外手术,全部植入PMMA一体型人工晶体。第三组25例(25只眼)切口为10.00mm,全部行现代囊外及PMMA人工晶体植入术。术后一周子术性散光改变为:第一组:1.11±0.64D,第二组:3.96±1.60,第三组;4.19±1.18D。第一组与第二、三组有统计学上的差别(P<0.05),而第二,三组无差别(P>0.05),在术后6月第一,二,三组之间都有显著差别(P<0.05)。角膜地形图的SRI,SAI及角膜主要轴线上的变化在小切口为最小。我们认为,白内障小切口超声乳化术后角膜表面形态的变化极少,术后屈光状态及视力较稳定,值得推广。

Corneal curvature changes following cataract extraction with different incision size in 75 patients (75 eyes) were studied by topographic modeling system(TMS) . Cases were subdivided into three groups. Group Ⅰ: including 25 cases(25 eyes), who had phacoemulsification (PHCO) and implanted with a foldable silicone lens through 4 mm incision; Group Ⅱ, 25 cases (25 eyes) had either extracapsular cataract extraction(P-ECCE) or PHCO through 7.5 mm incision and implanted with 6.5mm polymethylmethacylate(PMMA) Posterior chamber lens(PC-L); Group Ⅲ, 25 cases (25 eyes) had a conventional P-ECCE procedure and implanted with a PMMA-PC-L through 10 .0mm incision .Preoperative and postoperative cylin- der dioptric power were documented based on the corneal topography data and by using Vector-Jaffe analysis in order to estimate the surgically induced cylinderical changes, It showed that group I had significantly less changes compared with the other two groups at all follow-up periods (P&lt;0.05). Our topographic analysis clearly demonstrated that small incision (group I) produced less corneal curvature changes and it stabilized sooner that large incision. Over 84% of eyes in group I achieved an uncorrected visual acuity of 0.6 or better at six months following operation compared with 68% in group II and 40% in group III, which was statistically significant. We concluded that small incision and PHCO procedure induced significantly less astigmatism, less changes of corneal shape,faster postoperative recovery, better visual rehabilitation and more stable refraction than that of conventional EGCE with PC implantation. We also believe that corneal topography is an invaluable clinical tool with many advantages and probably will replace keratometry in standard clinical practice and research works .