选择性散光轴切口对白内障超声乳化术后角膜散光的影响

目的 探讨根据患者术前角膜散光不同,在不同部位选择性预设散光轴透明角膜切口行白内障超声乳化联合后房型折叠式人工晶状体植入术,对术后患者角膜散光的影响.方法 收集老年性白内障患者102例150只眼,分为选择性散光轴位的透明角膜切口(A组)、颞侧透明角膜切口(B组)和11点方位透明角膜切口(C组)3组,施行超声乳化联合折叠式人工晶状体植入术,比较术后视力及角膜散光的变化情况.结果 术后3月视力≥1.0,A组67%,B组56%,C组50%,差异有统计学意义(P＜0.01);A组术后3个月平均角膜散光低于B、C组(P＜0.05),较术前平均减少了0.32D(P＜0.05);且A组中19例术前角膜散光度≥1.00D的患者,术后3个月角膜散光度减少了0.71D(P＜0.05).术后3个月平均SLA,A组最小(P＜0.05).结论 选择在患者角膜屈光力最大轴向上行个体化的透明角膜切口,能减少患者术后角膜散光,有效控制白内障超声乳化手术源性角膜散光,进一步提高患者术后视力,尤其适用于术前角膜散光在≥1.00D的白内障患者.

Abstract：

Objective To investigate the surgically induced refractive change after phacoemulsification with selective maximum astigmatic axis clear incision. Methods Phacoemulsification was performed on 102 cases of 150 eyes with senile cataract through a clear corneal incision without suture. The changes of corneal astigmatism before and after operation in group A (incision at the maximum astigmatic axis) or B (incision at the temporal) and C (incision at the 11:00) were compared. Results Three months after the opera tion, the Best correction visual acuity more than 1.0, were 67% in group A, 56% in group B and 50% in group C (P ＜0.01). The mean postoperative astigmatism of group A decreased 0.32 D than the preoperative one (P ＜0.05) and was less than the postoperative one of group B or C. Postoperatively, the mean astigmatism of 19 patients who preoperative astigmatism more than 1.00D in group A decreased 0.71 D (P ＜0.05). Among the three groups, the mean postoperative surgically induced astigmatism (SIA) of group A was minimum (P ＜0.05).Conclusions The incision placed on the maximum astigmatic axis in phacoemulsification is worth to be recommended, because of the corneal astigmatism can be significantly reduced postoperatively, the SIA can be controlled effectively and patients can get a better visual acuity, especially to patients preoprative astigmatism more than 1.00D.     

不同透明角膜切口对白内障超声乳化术后角膜散光影响

目的 研究不同部位、不同方式的透明角膜切口白内障超声乳化联合后房型折叠式人工晶状体植入术对角膜散光的影响.方法 回顾性临床自身对照研究.将2009年3月至12月在广州医学院第二附属医院眼科就诊的96例(112只眼)白内障患者随机分为3组:A组颞侧透明角膜切口34例(39只眼);B组11:00钟方位透明角膜切口26例(31只眼);C组角膜曲率引导下透明角膜切口(切口位于角膜最大屈光轴方向)36例(42只眼).比较3组病人术前、术后1周、1个月、3个月的视力及角膜散光度变化.结果 术前、术后1周、3组间裸眼视力的差异无统计学意义(P值均>0.05);而术后1个月和3个月C组裸眼视力显著优于A、B组(P值均<0.05),而A组与B组间的差异无统计学意义(P值均>0.05).C组在术后1个月和3个月的角膜散光度显著小于A、B组(P值<0.05).结论 角膜曲率引导下位于角膜最大屈光轴方向的切口对白内障手术术后角膜散光影响最小,并有利于术后视力较快恢复.

Abstract：

Objective To investigate the effect of phacoemulsification with different transparent corneal incisions and foldable posterior chamber intraocular lens implantation on corneal astigmatism. Methods All 112 eyes of 96 patients with cataract were divided into three groups randomly, group A, received superior temporal clear corneal incision(39 eyes of 34 cases); group B, received superior clear corneal incision at 11 O'clock(31 eyes of 26 cases); group C, received steepest corneal meridian as guided by corneal(42 eyes of 36 cases). The changes of corneal astigmatism and visual acuity were determined before and 1 week, 1 month and 3 months after operation. Results There was no statistically significant(P >0.05)in visual acuity in three groups before and after operation 1 week; 1 and 3 months after operation the visual acuities in group C were much better than those of the group A and B(P <0.05), though there was no statistically significant(P >0.05)between group A and B; 1 and 3 months after operation the corneal astigmatism of group C was much lower than in group B and group C(P <0.05). Conclusions The incision at the steepest corneal meridian guided by corneal has the least effect on corneal astigmatism and can improve visual acuity rapidly.     

Factors associated with corneal astigmatism change after ptosis surgery

AIM: To evaluate the predictive factors of postoperative corneal astigmatism change in ptosis patients who underwent ptosis surgical repair. METHODS: Patients who underwent levator resection at Oculoplastic service of the Department of Ophthalmology, Naresuan University Hospital, Thailand between September 2017 and August 2019 were retrospectively evaluated. Changes in degree and axis of corneal astigmatism after ptosis surgery were compared based on patient factors consisting of age at operation, sex, preoperative margin-reflex distance (MRD) 1, and preoperative degree and axis of corneal astigmatism. RESULTS: Forty-two eyes of 28 patients were included in the study. Wilcoxon signed ranks test showed a significant postoperative corneal astigmatism change only in a subgroup of eyes with preoperative astigmatism of ≥1.5 diopters (D; P=0.006). Furthermore, 72.2% (13/18) of the eyes with preoperative astigmatism of ≥1.5 D showed a reduction of astigmatism after eyelid surgery, with the mean astigmatic change of 0.65 D. Majority of preoperative eyes demonstrated with-the-rule astigmatism pattern (45.2%), of which 57.9% showed a reduced degree of astigmatism. CONCLUSION: In patients undergoing ptosis surgery, the data demonstrate for the first time the association between postoperative corneal astigmatism change and a preoperative corneal astigmatism of ≥1.5 D. Thus, we encourage considering severity of corneal astigmatism prior to cataract or refractive surgery planning in ptosis patients, especially with toric-intraocular lens, to avoid the possibility of calculation error.     

白内障手术同时矫正术前散光的研究进展

随着白内障手术的日臻完美,术后残留散光逐渐成为影响患者获得理想屈光状态的主要原因之一.目前,散光矫正已成为屈光性白内障手术的重要内容.白内障手术同时矫正散光的方法主要包括:利用手术切口或散光角膜切开术矫正散光,选择植入散光型人工晶状体.这些方法各有其适应证及优缺点.术前散光检测及散光矫正方案设计是该手术的核心内容.散光矫正效果受多种因素影响.本文就以上内容对白内障手术同时矫正术前散光方面的研究进展作一综述.(中华眼科杂志,2011,47:573-576)

Abstract：

With the increasing progress of cataract surgery, the postoperative residual astigmatism has become one of the factors that influences the desirable refractive outcome for patient. Correction of astigmatism has become an important aspect of refractive cataract surgery. There are several options for correcting astigmatism at the time of cataract surgery, which include using the cataract incision or astigmatic keratotomy to counteract pre-existing astigmatism, or using a toric intraocular lens (Toric IOL). All of these choices have their operational indications, inherent advantages and disadvantages. The central concern of astigmatism surgery lies in the preoperative measurement and subsequent surgical planning for its correction. And the correction effect will be influenced by various factors. This paper reviews the recent progress in treating astigmatism at the time of cataract surgery based on the above points.     

Characteristics of posterior corneal astigmatism and aberration in cataract patients with high myopia北大核心CSCD

Objective: This study was to investigate the characteristics of posterior corneal astigmatism (PCA) and aberration in cataract patients with high myopia. Methods: A retrospective study was designed. Two hundred and eighty-two eligible eyes of 190 cataract patients were enrolled in Eye and ENT Hospital of Fudan University from September to December, 2014.The eyes were classified into two groups according to axial length (AL): high myopia group with 139 eyes (AL≥26 mm) and control group with 143 eyes (AL was 20 to 25 mm). The mean keratometric mid-radius of curvature (Km), corneal central thickness (CCT), astigmatism and aberrations were measured by the rotating Scheimpflug System (Pentacam), and the AL were measured by the partial coherence interferometry (IOL Master). This study followed the Helsinki declaration, and was approved by the Ethic Committee of Eye and ENT Hospital, Fudan University. Informed consent was signed from each patient. Results: In high myopia group, the mean PCA was 0.3 D (range 0~0.9 D) and 92.8% eyes had PCA values <0.5 D. The steep corneal meridian was aligned vertically (60°~120°) in 87.1% eyes for the posterior corneal surface. There was no significant difference in PCA between the high myopia group and the control group (P=0.797). Significant positive linear correlations was found between PCA and anterior corneal astigmatism (ACA), PCA and anterior corneal root mean square (RMS), PCA and anterior lower-order RMS, PCA and posterior corneal RMS, PCA and posterior high-order RMS, PCA and posterior lower-order RMS (r=0.235, P=0.005; r=0.217, P=0.010; r=0.229, P=0.007; r=0.395, P=0.000; r=0.243, P=0.004; r=0.384, P=0.000). Compared with total corneal astigmatism (TCA), anterior corneal measurements overestimated with-the-rule astigmatism (WTR) by a mean of (0.27±0.18)D in 65.67% eyes, underestimated against-the-rule astigmatism (ATR) by (0.27±0.18)D in 88.10% eyes and underestimated oblique astigmatism (Obl) by (0.22±0.10)D in 63.33% eyes. Compared with total corneal aberrations, anterior corneal aberrations measurements overestimated by (0.275±0.176)μm in 87.05% eyes, and the anterior corneal astigmatism types had no effect on the result. Conclusions: In high myopia group, 92.8% eyes had PCA values <0.5 D and the main astigmatism type in posterior corneal surface was ATR. The posterior corneal astigmatism and aberration were needed to consider in choosing intraocular lens (IOL) before cataract surgery. Copyright © 2018 by the Chinese Medical Association.     

Acrysof toric人工晶状体的临床应用研究

Objective To determine the efficacy and rotational stability of a posterior chamber single-piece toric intmocular lens(IOL)to correct preexisting corneal astigmatism in cataract patients.Methods Thirty one eyes of 25 patients who underwent phacoemulsification and foldable Aerysof toric IOL implantation from January 2008 to October 2008 were included in the study.The cylindrical IOL power was 1.5 diopters (D)(n=19),2.25 D(n=7),or 3.00 D(n=5).As a comparison,30 eyes of 21 patients meeting the same preoperative criteria for degree of corneal cylinder were enrolled to have a spherical(nontoric)IOL implanted.The data for both study and control groups were analyzed prospectively.Phacoemuisification was performed through a temporal clear corneal self-sealing incision.Outcomes of LogMAR visual acuity(without correct,with spherical correction and with best correction),refractive and keratometric astigmatism after early postoperative(one week)and long-term(3 months)follow-ups were evaluated.IOL axis rotation was also observed in the study group.Results At last follow-up,all patients achieved LogMAR 0.3(20/40)or better UCVA in the toric IOL group,while 86.7% achieved LogMAR 0.3(20/40)or better UCVA in the spherical IOL group.The mean postoperative refractive cylinder was 0.44±0.24 D in the toric IOL group and 1.44± 0.30D in the spherical(nontoric)IOL group.In 21 eyes(77%),the IOL axis was rotated less than 3 degrees.In all 27 eyes,the maxima rotation of the toric IOL axis was 9 degrees.Conclusions Early postoperative and long-term follow-ups results indicate that phacoemulsification and the Acrysoftoric IOL implantation is a largely predictable effective and stable surgical option to correcting preexisting astigmatism in cataract surgery.     

Effect of the posterior corneal surface on total corneal astigmatism in patients with age-related cataract

AIM: To explore the effect of the posterior astigmatism on total corneal astigmatism and evaluate the error caused by substituting the corneal astigmatism of the simulated keratometriy (simulated K) for the total corneal astigmatism in age-related cataract patients. METHODS: A total of 211 eyes with age-related cataract from 164 patients (mean age: 66.8±9.0y, range: 45-83y) were examined using a multi-colored spot reflection topographer, and the total corneal astigmatism was measured. The power vector components J0 and J45 were analyzed. Correlations between the magnitude difference of the simulated K and total cornea astigmatism (magnitude differenceSimK-Tca), anterior J0, and absolute meridian difference (AMD) between the anterior and posterior astigmatisms were calculated. To compare the astigmatism of the simulated K and total cornea both in magnitude and axial orientation, we drew double-angle plots and calculated the vector difference between the two measures using vector analysis. A corrective regression formula was used to adjust the magnitude of the simulated K astigmatism to approach that of the total cornea. RESULTS: The magnitude differenceSimK-Tca was positively correlated with the anterior corneal J0 (Spearman’s rho= 0.539; P<0.001) and negatively correlated with the AMDR (Spearman’s rho=-0.875, P<0.001). When the anterior J0 value was larger than 1.3 D or smaller than -0.8 D, the errors caused by determining the total corneal astigmatism with the karatometric calculation tended to be greater than 0.25 D. An underestimation by 16% was observed for against the rule (ATR) astigmatism and an overestimation by 9% was observed for with the rule (WTR) astigmatism when ignoring the posterior measurements. CONCLUSION: Posterior corneal astigmatism should be valued for more precise corneal astigmatism management, especially for higher ATR astigmatism of the anterior corneal surface. We suggest a 9% reduction in the magnitude of the simulated K in eyes with WTR astigmatism, and a 16% addition of the magnitude of the simulated K in eyes with ATR astigmatism.     

Modified Scleral Flap Incision to Reduce Corneal Astigmatism after Intraocular Lens Implantation

To investigate a simple method during extracapsular cataract extraction with posterior chamber intraocular lens implantation in order to reduce surgically induced corneal astigmatism.Methods: A modified scleral flap incision was used in the extracapsular cataract extraction with intraocular lens implantation and the postoperative changes in conreal astigmatism was observed.Results: The peak value of postoperative corneal astigmatism was 3. 60 D, and the corneal astigmatism regression was 2. 11 D, surgically induced astigmatism was less significant in modified scleral flap incision group than that in conventional limbal incison group (P<0. 05).Conclusions: The modified scleral flap incision is an ideal incision for cataract extraction with intraocular lens implantation when phacoemulsifier is not available. Eye Science 1995; 11-. 136-139.     

The Comprehensive Control of Astigmatism during and Following Intraocular Lens Implantation.

The operating corneoloscope and Terry operative keratometer were used respectively in 29 and 34 eyes during the intraocular lens implantation to measure the corneal astigmatism qualitatively or quantitatively,so that the tension of incision closure could be adjusted. The surgically induced astigmatism in qualitative group two weeks after the operation was 3. 5 ± 1. 70 D and that in quantitative group was 2. 56±1. 60 D. There were 55.17% and 38. 24% of the eyes with over 2. 00 D corneal astigmatism in qualitative and quantitative group two months after the surgery. The astigmatism of both groups at the early stage after the operation was significantly lower than that of the control group (p<0. 05). Argon laser, Nd: YAG laser or razor-blade were used to cut 1 to 3 limbal sutures in 64 eyes with over with-the-rule astigmatism 2. 25 D at the early stage (2 months) after the operation. One hour after suture cutting, the with-the-rule corneal astigmatism reduced significantly with an average of 2.61 D. The     

Astigmatism outcomes of horizontal temporal versus nasal clear corneal incision cataract surgery

PURPOSE: To compare the short- and long-term astigmatism outcomes after cataract surgery using temporal clear horizontal corneal incisions and nasal horizontal clear corneal incisions. SETTING: Wilmer Eye Institute, Johns Hopkins Hospital, Baltimore, Maryland, USA. METHODS: This retrospective study included a consecutive series of eyes having phacoemulsification with implantation of a 6.0 mm foldable acrylic intraocular lens through a 3.5 mm horizontal clear corneal incision at 180 degrees (temporal incision in right eyes, nasal incision in left eyes). Astigmatism was measured by keratometry readings before surgery and 6 weeks and 12 months postoperatively. RESULTS: The mean preoperative astigmatism in the 178 eyes (94 right, 84 left) of 161 patients was 0.78 diopter (D); 54.5% of eyes had against-the-rule (ATR) astigmatism, 22.5% had with-the-rule (WTR) astigmatism, and 14.0% were astigmatically neutral. A significant shift toward WTR astigmatism occurred postoperatively. At 6 weeks, 48.3% of eyes had WTR astigmatism and 23.0% had ATR astigmatism. At 12 months, 43.8% had WTR astigmatism and 25.8% had ATR astigmatism. Vector analysis revealed a mean surgically induced astigmatism (SIA) of 1.17 D at 6 weeks and 1.04 D at 12 months. The side of the incision significantly affected SIA. At 6 weeks, temporal incisions yielded a mean SIA of 0.74 D and the nasal incisions, of 1.65 D. This trend in SIA persisted at 12 months: 0.71 D for temporal incisions and 1.41 D for nasal incisions. CONCLUSIONS: Cataract surgery using a horizontal clear corneal incision induced WTR astigmatism 6 weeks and 12 months postoperatively. Temporal incisions induced significantly less astigmatism than nasal incisions.     

Effect of central corneal thickness on surgically induced astigmatism in cataract surgery

PURPOSE: To evaluate the effect of central corneal thickness (CCT) on surgically induced astigmatism (SIA) in cataract surgery using temporal clear corneal incisions. SETTING: Department of Ophthalmology, Seoul National University Hospital, Seoul, Korea. METHODS: The retrospective nonrandomized clinical study comprised 129 eyes that had cataract surgery performed through a sutureless temporal clear corneal incision. Eyes were categorized according to the axis of the preoperative astigmatism: against the rule (ATR, 0 to 45 degrees; n = 64) or with the rule (WTR, 46 to 90 degrees; n =65). Corneal topography was taken preoperatively and 1 day and 2 months postoperatively to evaluate the change in the cornea. The SIA was calculated using the polar method from simulated keratometric readings obtained with topography. Correlations between SIA and CCT were analyzed by linear regression analysis and compared between the ATR and the WTR groups. RESULTS: One day postoperatively, the SIA was negatively correlated with CCT in the ATR group but not in the WTR group (P =.050 versus P =.92; linear regression analysis). At 2 months, the correlation between CCT and SIA was no longer statistically significant. CONCLUSIONS: Central corneal thickness was negatively correlated with the amount of SIA immediately postoperatively when the preoperative astigmatism was ATR. The correlation was not present 2 months after surgery. These results may be applied to abnormally thin corneas such as those after keratorefractive surgery.     

同轴微切口白内障超声乳化术后角膜散光的临床观察

目的:评价2.2mm同轴微切口白内障超声乳化手术后角膜散光的变化。方法:老年性白内障患者56例78眼,将患者随机分为2组,2.2mm组38眼,3.0mm组40眼,分别行2.2mm同轴微切口白内障超声乳化联合人工晶状体(IOL)植入术及3.0mm常规白内障超声乳化联合IOL植入术,术后1,3mo评价术眼裸眼视力(uncorrected visual acuity,UCVA)、角膜散光、术源性角膜散光(surgically induced astigmatism,SIA)。结果:术后1mo,2.2mm组角膜散光为0.85±0.42D,3.0mm组角膜散光为1.18±0.37D,两组角膜散光比较有统计学差异(P<0.05)。术后3mo,2.2mm组角膜散光为0.74±0.40D,3.0mm组角膜散光为1.00±0.30D,两组角膜散光比较有统计学差异(P<0.05)。术后1mo和3mo,3.0mm组的SIA大于2.2mm组(P<0.05),3.0mm组术后1mo平均SIA大于术后3mo平均SIA(P<0.05),2.2mm组术后1mo和3mo SIA没有统计学差异(P>0.05)。术后UCVA,在术后1mo和3mo,2.2mm组均优于3.0mm组。结论:2.2mm同轴微切口白内障超声乳化手术后能产生更小的SIA和更好的UCVA。     

两种不同切口超声乳化术对合并低度角膜散光白内障患者的角膜散光和视力的影响

目的　观察在合并低度角膜散光的白内障患者中行陡峭轴角膜切口和颞侧角膜切口超声乳化术后角膜散光和视力的变化。方法　将我院收治的合并角膜散光≤0.50 D的年龄相关性白内障患者共60例(60眼)根据术中切口不同分成A、B两组。A组30例行陡峭轴切口,B组30例行颞侧角膜切口。观察术前及术后1周、1个月、3个月裸眼视力（uncorrected visual acuity,UCVA)、最佳矫正视力（best corrected visual acuity,BCVA)、角膜散光、术源性散光(surgically induced astigmatism,SIA),并进行统计学分析。结果　术后1个月、3个月,A组UCVA均优于B组（均为P＜0.05）;两组术后各时间点BCVA比较差异均无统计学意义（均为P＞0.05）,但均较术前明显提高（均为P<0.05）。A组UCVA术后3个月优于术后1个月、术后1个月优于术后1周,差异均有统计学意义 (均为P＜0.05)。A组BCVA于术后1个月基本稳定。术后1周、1个月、3个月,A组角膜散光均低于B组（均为P＜0.05）。A组角膜散光术后3个月为（0.26±0.20）D,略低于术前的（0.32±0.13）D,但差异无统计学意义（P=0.42）。B组术后3个月角膜散光为（0.62±0.45）D,高于术前的（0.23±0.17）D,差异有统计学意义（P<0.05）。术后1周A组 SIA为（1.28±0.63）D,高于B组的（0.77±0.39）D,差异有统计学意义（P=0.01）。术后1个月、3个月两组SIA比较差异均无统计学意义（均为P＞0.05）。结论　术前角膜散光≤0.50 D的白内障患者行白内障超声乳化手术时,选择陡峭轴切口并不能矫正术前角膜散光,但能减小术后总角膜散光,且可以有效提高术后UCVA,术后效果优于颞侧角膜切口。     

Astigmatism after superonasal and superotemporal clear corneal incisions in phacoemulsification

Purpose To determine the astigmatism outcomes after cataract surgery performed using superonasal and superotemporal clear corneal incisions. Setting Department of Ophthalmology, Kartal Training and Research Hospital, Istanbul, Turkey. Methods This prospective study includes consecutive 45 eyes of 34 patients having phacoemulsification with implantation of foldable acrylic intraocular lens through a corneal tunnel incision between January and April 2004. The right eye always had a superotemporal incision while the left eye a superonasal incision. Astigmatism was measured by keratometry readings before surgery and 3rd, 15th, and 45th days postoperatively. The surgically induced astigmatism (SIA) was calculated by the vector analysis using the Holladay–Cravy–Koch method at 3rd day, 2nd and 6th weeks postoperatively. Results The mean preoperative astigmatism was 0.74 ± 0.45 diopter (D) in the temporal incision group and 0.69 ± 0.39 D in the nasal incision group. Fifty-eight percent of eyes had against-the-rule (ATR) astigmatism, 26% had with-the-rule (WTR) astigmatism, and 16% were astigmatically neutral. At 6 weeks, 46% of eyes had ATR astigmatism and 35% had WTR astigmatism. The mean total astigmatism was lower in the temporal incision group than in the nasal incision group at all successive examinations postoperatively. Although the total astigmatism decreased at 6 weeks in both groups, temporal incisions yielded less total and surgically induced astigmatism (P < .05). Conclusions Cataract surgery using superotemporal incision induced significantly less SIA in the early postoperative period.     

用3．5mm切口的白内障超声乳化术降低术前散光

目的：评价3．5mm上方巩膜隧道切口和颞侧透明角膜切口的白内障术后角膜散光，手术所致散光和裸眼视力。方法：根据术前角膜散光轴位选切口的白内障超声乳化摘出联合软性人工晶状体植入术共89眼，A组：47眼散光为顺规性，切口选在上方巩膜。B组：42眼散光为逆规性，切口选在颞侧透明角膜，术前，术后3天－1年，分别测量角膜散光，查裸眼视力，用Cravy法计算手术所致散光。结果：术前，术后3天，1，3，6，12月的平均散光，在A组分别为1．17D，1．10D，1．01D，0．88D，0．85D和0．82D，在B组分别为1．22D，1．03D，1．04D，1．01D，0．95D和1．00D。术后12月内，手术所散江，在A组为－0．22D－0．39D，在B组为＋0．57D－＋0．26D。术后3天裸眼视力≥0．5者，在A组和B组分别占85．1％和81．0％，结论：在这研究中，两种切口均能降低术前散光，术后眼视力恢复更理想。     

不同透明角膜切口导致的角膜屈光力动态变化对比

目的:探讨白内障超声乳化术中,颞侧和上方2.8mm透明角膜切口引起的角膜屈光变化。方法:收集老年性白内障患者60例60眼,分成A组32例32眼(颞侧角膜切口组),B组28例28眼(上方角膜切口组)。检查术前、术后1d;1wk;1mo和3mo的视力、手术源性散光和角膜地形图。结果:A,B两组术前散光分别为0.67±0.31D,0.70±0.35D。术后1d;1wk;1,3mo,A组的散光分别为0.85±0.41D,0.75±0.38D,0.70±0.35D,0.68±0.33D;B组分别为1.18±0.46D,0.98±0.39D,0.80±0.31D,0.73±0.33D。术后各阶段散光均高于术前。A组的散光小于B组(P<0.05)。术后第1d各组散光最大,以后逐渐减小。术后1d;1wk;1,3mo,A组的手术源性散光(surgicallyin-ducedastigmatism,SIA)分别为0.65±0.30D,0.50±0.28D,0.43±0.21D,0.40±0.18D;B组分别为0.85±0.38D,0.71±0.35D,0.62±0.25D,0.49±0.20D。术后1d,A组SIA较B组小(P<0.05);各组SIA均随时间推移而减小,但A组SIA始终小于B组(P<0.05)。结论:颞侧切口操作方便,术后的角膜散光状态和手术性散光均小于上方切口。     

Enlargement of the temporal clear corneal cataract incision to treat pre-existing astigmatism

PURPOSE: To evaluate the effect of enlarging the temporal clear corneal cataract incision on pre-existing against-the-rule astigmatism. METHODS: We performed a prospective study of 21 eyes of 21 consecutive patients with astigmatism greater > or = 1.75 D, who underwent temporal clear corneal cataract surgery by phacoemulsification. Patients were divided into two groups. The first group, with medium astigmatism, consisted of 14 patients (14 eyes) with 1.75 to 2.74 D of against-the-rule astigmatism, and had an incision enlarged to 4.5 mm. The second group, with higher astigmatism, consisted of seven patients (seven eyes) with 2.75 to 3.75 D of against-the-rule astigmatism and had an incision enlarged to 5.5 mm. Corneal topography was performed preoperatively and 24 months postoperatively on all eyes. Surgically induced cylinder changes were compared by examining preoperative and postoperative keratometric power using vector analysis. RESULTS: Mean preoperative cylinder in the medium against-the-rule astigmatism group was 2.10 +/- 0.23 D and mean postoperative cylinder at 3 months was 1.17 +/- 0.29 D. Using vector analysis, mean change in cylinder in the medium group was 0.93 +/- 0.42 D (P < .001). In the higher against-the-rule astigmatism group, mean preoperative cylinder was 2.85 +/- 0.10 D and mean postoperative cylinder at 3 months was 1.63 +/- 0.38 D. Mean change in cylinder in the higher astigmatism group was 1.34 +/- 0.58 D (P < .001). For both groups, Student's t-test showed that the postoperative decrease in cylinder was statistically significant (P = .005). CONCLUSION: By enlarging the size of the standard (2.8 to 3.5 mm) temporal clear corneal cataract incision, pre-existing against-the-rule astigmatism was reduced.     

手法小切口白内障摘出术后角膜散光变化的研究

目的:探讨手法小切口白内障摘出联合人工晶状体植入术后角膜散光的变化。方法:将57例86眼老年性白内障患者随机分成两组,A组42眼行手法小切口白内障摘出联合人工晶状体植入术,B组44眼行白内障超声乳化联合人工晶状体植入术。分别于术前、术后1,3mo用角膜地形图测量角膜散光度并计算手术源性散光。结果:术后1mo,A组与B组的平均手术源性散光分别为1.05±0.49,0.71±0.45,差异有统计学意义(P<0.05);术后3mo,A组与B组的平均手术源性散光分别为0.66±0.34,0.59±0.31,差异无统计学意义(P>0.05)。结论:术后早期白内障超声乳化术比手法小切口白内障摘出术引起的角膜屈光改变更小,术后3mo两者的屈光改变接近一致,均达到屈光稳定状态。     

K值引导下不同切口位置对小切口白内障术后角膜散光影响的观察

目的观察角膜曲率(K值)引导下小同切口位置对小切口白内障术后角膜散光的影响。方法 58例患者(58只眼)随机分为A、B两组,A组30例(30眼)切口全部选在上方,B组28例(28只眼)根据角膜K值选在切口位置,垂直径线K值大者切口选在上方,水平径线K值大的选在颞侧,所有患者均采用距角膜缘3mm的巩膜隧道切口,不缝合。观察术前及术后3个月时角膜散光、术后3个月时裸眼视力,并进行统计学分析。结果 A组术前和术后3个月时角膜散光为(1.65±0.42)D、(1.61±0.45)D,B组为(1.87±0.55)D,(0.79±0.34)D,B组术后散光明显降低,同A组相比差异有统计学意义(P<0.05);两组术后裸眼视力≥0.5者分别为70%、89.3%,差异有统计学意义。结论根据K值选择切口位置,可有效降低白内障术后角膜散光,提高患者视力。