Corneal topographic changes induced by different oblique cataract incisions

PURPOSE: To compare astigmatic and topographic changes induced by different oblique cataract incisions. SETTING: Department of Ophthalmology, Hospital of San Donà di Piave, Venice, Italy. METHODS: One hundred sixty-eight eyes having phacoemulsification were randomly assigned to 1 of 3 groups: 3.5 mm clear corneal incision (CCI), 60 eyes; 5.5 mm sutured CCI, 54 eyes; 5.5 mm scleral tunnel, 54 eyes. Incisions lay on the 120 degree semimeridian. Corneal topography was performed preoperatively and 1 week and 1 and 3 months postoperatively. Simulated keratometric readings were used to calculate astigmatism amplitude and surgically induced astigmatism (SIA). Postoperative topographic changes were determined by subtracting the preoperative from the postoperative numeric map readings. RESULTS: Three months postoperatively, the mean SIA in the right and left eyes, respectively, was 0.68 diopter (D) +/- 1.14 (SD) and 0.66 +/- 0.52 D in the 3.5 mm CCI group, 1.74 D +/- 1.43 D and 1.64 +/- 1.27 D in the 5.5 mm CCI group, and 0.46 +/- 0.56 D and 0.10 +/- 1.08 D in the scleral tunnel group. Right and left eyes showed similar SIA amplitude but different SIA axis orientation. The SIA was significantly higher in the 5.5 mm CCI group than in the other 2 groups 1 and 3 months postoperatively (P <.01). All groups showed significant wound-related flattening and nonorthogonal steepening at 2 opposite radial sectors. Topographic changes were significantly higher in the 5.5 mm CCI group and significantly lower in the scleral tunnel group. CONCLUSIONS: Right and left eyes showed similar SIA amplitude but different SIA axis orientation and topographic modifications, probably because of the different superotemporal and superonasal corneal anatomic structure. The 5.5 mm CCI induced significantly higher postoperative astigmatism, SIA, and topographic changes.     

两种不同切口人工晶状体植入术后角膜地形图对比分析

目的 研究两种不同切口人工晶状体植入后角膜形态和散光的变化。方法 通过３．２ｍｍ透明角膜切口植入折叠人工晶状体５０眼和６．０ｍｍ巩膜隧道切口植入ＰＭＭＡ人工晶状体４８眼,术后应用计算机辅助角膜地莆图仪对这些病人的角膜形态进行检查。结果 角膜组术后早期角膜地形图垂直于切口径线的角膜轻度变平,于术后１个月即可稳定。巩膜组有膜垂直轴上出殃蝴蝶结样改变,而后蝴蝶结逐渐变小,或向水平方向转变而减少,至３个月时基本稳定。两组在术后１天至１个月的角膜散光和手术性角膜散光巩膜组大于角膜组（Ｐ〈０．０５）。结论 ３．２ｍｍ透明角膜切口组术后角膜形态改变小,视力恢复快。     

Surgically induced astigmatism after micro and small clear temporal corneal incision in cataract surgery

PURPOSE: To compare surgically induced astigmatism among 3 sizes of temporal corneal incisions in cataract surgery. PATIENTS AND METHODS: A retrospective review was carried out of case records of 48 patients (64 eyes) who underwent cataract surgery. The length of the corneal incision was 1.6 mm in five eyes, 2.2 mm in 33 eyes, and 3.0 mm in 26 eyes. Astigmatism was measured by keratometry readings before and 1 week, 1 month, and 3 months after surgery. Surgically induced astigmatism was calculated by vector analyses using the Cravy method. RESULTS: One week postoperatively, the mean surgically induced astigmatism was 0.00 +/- 0.69 diopter(D) in the 1.6 mm group, -0.05 +/- 0.61 D in the 2.2 mm group and 0.44 +/- 0.57 D in the 3.0 mm group. Three months after surgery, the mean surgically induced astigmatism was -0.05 +/- 0.08 D in the 1.6 mm group, -0.04 +/- 0.47 D in the 2.2 mm group and 0.47 +/- 0.59 D in the 3.0 mm group. The surgically induced astigmatism was significantly less in the 2.2 mm group than in the 3.0 mm group. CONCLUSION: The amount of induced astigmatism was significantly less in temporal corneal micro-incision cataract surgery than in small incision surgery.     

2.2 mm与2.75 mm切口超声乳化术后角膜散光变化的对比

目的 比较2.2 mm与2.75 mm透明角膜切口（CCI）白内障超声乳化术后角膜散光的变化.方法 前瞻性随机对照临床研究.将134例（167眼）白内障患者按掷硬币法随机分为2组：2.2 mm切口组57例（70眼）和2.75 mm切口组77例（97眼）,术前角膜散光＜0.50 D者,做正上方切口,角膜散光≥0.50 D者,在最高屈光力子午线上做切口.测量2组术前,术后1周、1个月和3个月的UCVA、BCVA、角膜散光度（CAD）及轴向（CAA）.比较分析2组间及组内不同时间点视力及角膜散光变化的差异.数据采用重复测量资料的方差分析、独立样本t检验、两样本Wilcoxon秩和检验、独立样本R×C列联表的x2检验进行分析.结果 2组术后CAD总体较术前明显降低.2.2 mm组术前为（0.73±0.43）D,术后3个月为（0.49±0.36）D （P＜0.01）;2.75 mm组术前为（0.87±0.57）D,术后3个月为（0.53±0.38）D（P＜0.01）.2.2 mm组术后1周CAD有短暂增高（P＜0.05）,术后1个月时下降至术前水平（P＞0.05）;而2.75 mm组术后1周与术前比较无明显变化（P＞0.05）,术后1个月时明显低于术前（P＜0.05）.2组之间CAD变化幅度比较差异无统计学意义.2组组内手术前后CAA总体构成比较差异无统计学意义,组间比较差异亦无统计学意义.结论 最高屈光力子午线上做CCI,2.2 mm及2.75 mm的切口均能矫正部分术前角膜散光,且矫正角膜散光的作用无明显差异.     

Torque and flattening effects of clear corneal temporal and on-axis incisions for phacoemulsification

PURPOSE: To compare the torque and flattening effect induced by temporal or on-axis clear corneal incisions (CCIs) for phacoemulsification. SETTING: Moorfields Eye Hospital, London, United Kingdom. METHODS: Randomized controlled clinical trial on 62 eyes with cataract and mild to moderate corneal astigmatism (<2.60 diopters [D]) having phacoemulsification with a temporal CCI (temporal group) or on-axis CCI (on-axis group). Corneal astigmatism was assessed by corneal topography preoperatively and 3 weeks after surgery. The meridian of the incisions was marked on the cornea before local anesthesia was given to avoid anesthesia-related cyclotorsion. The surgically induced astigmatism (SIA) vector, torque, flattening effect, and accuracy of incision placement were analyzed in the 2 groups and compared with a paired t test. RESULTS: Three weeks after surgery, the on-axis CCI induced slightly more flattening of the meridian of the incision (mean -0.63 +/- 0.57 D [SD]) than the temporal CCI (mean -0.50 +/- 0.44 D); however, the differences were not statistically significant (P = .31). Simple algebraic difference showed a mean increase in astigmatism magnitude of 0.12 +/- 0.52 D in the temporal group and a mean reduction of 0.21 +/- 0.53 D in the on-axis group (P = .02). The mean absolute torque was 0.28 +/- 0.27 D and 0.53 +/- 0.37 D, respectively (P<.005). The absolute angle of error of incision placement (alpha) was greater after on-axis CCIs (mean 25.9 +/- 20.1 degrees) than after temporal CCIs (mean 14.5 +/- 14.3 degrees) (P = .01). CONCLUSIONS: In eyes with preoperative astigmatism less than 2.60 D, on-axis CCI phacoemulsification induced slightly more flattening along the incision meridian than temporal CCI phacoemulsification, although the differences were not significant. The on-axis CCI was associated with significantly greater absolute torque and angle of error than the temporal CCI. These factors could limit the benefit of placing the incision on axis when the aim is to reduce preoperative astigmatism in phacoemulsification.     

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。     

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。     

Effect of temporal and nasal unsutured limbal tunnel incisions on induced astigmatism after phacoemulsification

PURPOSE: To compare the surgically induced corneal astigmatism after unsutured temporal and nasal unsutured limbal tunnel incisions. SETTING: Departments of Ophthalmology, Marienhospital, Aachen, and Johann Wolfgang Goethe-University, Frankfurt am Main, Germany. METHODS: In a prospective clinical study, 42 eyes of 21 patients with a mean age of 75.1 years had phacoemulsification and implantation of a foldable hydrophobic acrylic intraocular lens using a 3.6 to 3.8 mm unsutured limbal tunnel incision. The right eye always received a temporal incision and the left eye, a nasal incision. Computerized videokeratography was performed preoperatively and 2 weeks and 6 months postoperatively. Surgically induced astigmatism was calculated by vector analysis using the Holladay-Cravy-Koch formula. The 2 groups were compared using a paired Wilcoxon test. RESULTS: The mean surgically induced corneal astigmatism in the temporal incision group was 0.62 diopters (D) +/- 0.48 (SD) 2 weeks postoperatively and 0.47 +/- 0.32 D at 6 months and in the nasal incision group, 1.55 +/- 0.84 D and 1.05 +/- 0.57 D, respectively. The difference between the groups was statistically significant (P <.05). CONCLUSIONS: There was a highly statistically significant difference in surgically induced corneal astigmatism after temporal and nasal unsutured limbal tunnel incisions. The degree of induced astigmatism and the difference between the temporal and the nasal incisions decreased over time. A nasal tunnel incision is not appropriate for astigmatism-neutral surgery.     

小切口白内障术后的早期角膜地形图分析

目的：研究白内障小切口术后角膜形态变化特点。方法：用角膜地形图对27例（34眼）白内障小切口手术患者进行检查,分析其术前,术后1周、1月、3月的角膜地表图变化。结果：术后1周仅产生手术源性散光0.52D,术后1月角膜散光及CIM值（角膜不规则系数）趋向稳定,裸眼视力≥0.5占26眼（76.42%）,SF值（角膜形状系数）术前术后无明显变化。结论：小切口具有早期角膜形态变化小、散光稳定、视力恢复快等优点,角膜地形图可准确全面反映白内障术后角膜形态变化。     

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。     

Intraocular pressure after small incision cataract surgery: temporal sclerocorneal versus clear corneal incision

PURPOSE: To compare intraocular pressure (IOP) after phacoemulsification and foldable intraocular lens (IOL) implantation using a temporal sclerocorneal or clear corneal incision. SETTING: Department of Ophthalmology, Johannes Gutenberg-University, Mainz, Germany. METHODS: One hundred patients (100 eyes) with cataract having phacoemulsification with posterior chamber IOL implantation were randomly assigned to receive a temporal sclerocorneal or clear corneal tunnel incision. Intraocular pressure was measured preoperatively and 6 hours, 1, 2, and 3 days, and 5 months postoperatively. Statistical significance was determined by nonparametric group comparisons using 2-sample random Wilcoxon tests. RESULTS: Six hours postoperatively, the median IOP increase was significantly higher in the sclerocorneal tunnel group (57%) than in the clear corneal incision group (18%) (P <.001). No significant between-group difference in IOP was found at 1, 2, or 3 days or 5 months. At 5 months, IOP was 0.6 mm Hg lower than preoperatively in the sclerocorneal tunnel group and 1.5 mm Hg lower in the clear corneal group. CONCLUSIONS: After phacoemulsification and foldable IOL implantation, the immediate postoperative IOP increase was higher in eyes having a sclerocorneal incision than in those having a clear corneal tunnel incision. These results could be important in eyes with decreased outflow facility or preexisting optic nerve damage.     

角膜切口对白内障手术后散光的影响

目的:观察沿角膜散光陡峭轴方向做透明角膜切口行白内障超声乳化联合人工晶状体植入术后散光和视力的变化。方法:根据IOL-Master检测结果选择角膜最大屈光力轴行3.0mm透明角膜切口做白内障超声乳化术42眼作为观察组(A组),常规颞上(右眼)、鼻上(左眼)3.0mm透明角膜切口白内障超声乳化术68眼作为对照组(B组)。检测术前、术后1d;1wk;1,3mo角膜散光和视力变化。结果:A组术前、术后1d;1wk;1,3mo视力分别为0.2±0.24,0.73±0.37,0.78±0.38,0.94±0.36,0.76±0.13;B组为0.17±0.2,0.82±0.3,0.84±0.2,0.77±0.26,0.8±0.36;差异无统计学意义(P>0.05)。A组术前、术后1d;1wk;1,3mo角膜散光度分别为1.01±0.10D,1.33±0.13D,1.15±0.14D,0.90±0.13D,0.89±0.12D;B组为0.95±0.13D,1.25±0.15D,1.07±0.13D,0.87±0.12D,0.82±0.11D。术后1d;1wk;1mo与术前相比散光度均无统计学意义(P>0.05)。两组术后3mo散光度与术前相比差异有统计学意义(P<0.05)。两组术后3mo裸眼视力≥0.8者分别为21眼(50%)和32眼(47%),两者相比有统计学意义(P<0.05)。结论:沿陡轴透明角膜切口白内障超声乳化联合人工晶状体植入术有助于患者视力提高及减少术后角膜散光。     

Corneal topographic changes following strabismus surgery in Grave's disease.

A computerized topographic analysis system was used to evaluate corneal changes after strabismus surgery in eight eyes of five patients with Graves' disease. All patients underwent inferior rectus muscle recession; three eyes also had medial rectus recession. Corneal topographic analysis revealed that, postoperatively, corneas steepened inferiorly and inferotemporally at 1.5 mm from corneal apex (p less than 0.05). The opposite effect was observed in the superior quadrant (average flattening of 1.20 +/- 0.32 D at 1.5 mm from corneal apex, and 1.08 +/- 0.39 D at 3.0 mm from corneal apex; p less than 0.05). Superotemporally, the cornea flattened by an average of 0.65 +/- 0.26 D at 3.0 mm from corneal apex, and superonasally 0.72 +/- 0.19 D at 3.0 mm from corneal apex (p less than 0.05). Central, nasal, and temporal cornea did not show statistically significant changes. Spherical equivalent did not change significantly after surgery. The amount of restriction and upgaze measured preoperatively was correlated weakly with inferior corneal steepening (r2 = 0.44; p = 0.046). These results are indicative that corneal topography may be influenced by strabismus surgery for Graves' disease through alteration of extraocular muscle tension or intraocular pressure.     

Controlling astigmatism in cataract surgery requiring relatively large self-sealing incisions

PURPOSE: To evaluate the results of a modified self-sealing incision for achieving astigmatic neutrality in cataract surgery requiring a 6.0 to 7.0 mm incision as well as the methods of correcting preexisting astigmatism using these incisions. SETTING: Department of Ophthalmology, Kushimoto Rehabilitation Center, Kushimoto, Japan. METHODS: To achieve astigmatic neutrality, a frown-shaped, oblique incision-the BENT (between 9 and 12 o'clock) frown-was used. To reduce preexisting against-the-rule or with-the-rule astigmatism, the incisions were placed on the temporal or superior steep astigmatic axis, respectively. A frown incision was used when aiming for mild astigmatic reduction and an arcuate incision when aiming for relatively large astigmatic reduction. RESULTS: In the 6.0 to 7.0 mm BENT frown incision group, mean flattening was minimal throughout 6 months of follow-up, with a maximum of 0.18 diopter (D) 1 week postoperatively. Surgically induced astigmatism was less than that with other incisions. Ninety-four percent of cases had a difference in absolute astigmatism of less than 0.50 D between preoperatively and 6 months postoperatively. Relatively large flattening was observed in eyes with 6.0 to 7.0 mm steep-axis incisions of superior arcuate, temporal arcuate, superior frown, and temporal frown, with means of 1.03, 0.79, 0.64, and 0.52 D, respectively, at 6 months. Ninety-eight percent of cases had a reduction in preexisting absolute astigmatism postoperatively. CONCLUSIONS: In cataract surgery using relatively large scleral self-sealing incisions, the BENT frown incision effectively achieved astigmatic neutrality. The incisions on the temporal or superior steep astigmatic axis (with selective shape) reduced astigmatism in almost all cases.     

Opposite clear corneal incisions to correct pre-existing astigmatism in cataract surgery

In cataract surgery, the clear corneal incision (CCI) has a small flattening effect on corneal curvature, which can be used to reduce pre-existing astigmatism (PEA). Adding an identical, penetrating CCI opposite the first one can enhance the flattening effect. The paired opposite CCIs (OCCIs) are placed on the steepest meridian axis to flatten it. One CCI is used to perform cataract surgery, and the opposite CCI is made to enhance the flattening effect on the cornea to modulate PEA. During the past 12 months, we have used 2.8 to 3.5 mm OCCIs in 33 eyes with PEA greater than 2.00 diopters (D) having cataract surgery. The mean astigmatism correction achieved with this technique was 2.06 D. This technique is simple and effective and yields stable results that rival those of arcuate keratotomy. The OCCI technique has a potential application for the correction of astigmatism in general refractive surgery. Opposite clear corneal incision nomograms with variables such as width, length, and distance from the limbus will be needed for future applications.     

Surgically induced astigmatism after 3.0 mm temporal and nasal clear corneal incisions in bilateral cataract surgery

Aims:

To compare the corneal refractive changes induced after 3.0 mm temporal and nasal corneal incisions in bilateral cataract surgery.

Materials and Methods:

This prospective study comprised a consecutive case series of 60 eyes from 30 patients with bilateral phacoemulsification that were implanted with a 6.0 mm foldable intraocular lens through a 3.0 mm horizontal clear corneal incision (temporal in the right eyes, nasal in the left eyes). The outcome measures were surgically induced astigmatism (SIA) and uncorrected visual acuity (UCVA) 1 and 3 months, post-operatively.

Results:

At 1 month, the mean SIA was 0.81 diopter (D) for the temporal incisions and 0.92 D for nasal incisions (P = 0.139). At 3 months, the mean SIA were 0.53 D for temporal incisions and 0.62 D for nasal incisions (P = 0.309). The UCVA was similar in the 2 incision groups before surgery, and at 1 and 3 months post-operatively.

Conclusion:

After bilateral cataract surgery using 3.0 mm temporal and nasal horizontal corneal incisions, the induced corneal astigmatic change was similar in both incision groups. Especially in Asian eyes, both temporal and nasal incisions (3.0 mm or less) would be favorable for astigmatism-neutral cataract surgery.     

不同位置角膜切口白内障超声乳化对角膜表面形态的影响

目的 探讨颞侧和上方3.2mm透明角膜切口白内障超声乳化联合折叠式人工晶状体植入术对角膜表面形态的不同影响.方法 收集老年性白内障患者44例54眼,将患者随机分为颞侧透明角膜切口组(A组)和上方透明角膜切口组(B组).检查术前、术后1 d、1周、1个月和3个月视力、手术源性散光(surgically induced astigmatism,SIA)和角膜地形图.结果 术后1d、1周、1个月、3个月,A组SIA分别为(0.70±0.34)D、(0.64±0.29)D、(0.60±0.27)D、(0.55±0.26)D,B组分别为(1.18±0.48)D、(1.05±0.42)D、(0.88±0.38)D、(0.77±0.35)D.术后1 d,A组SIA较B组小,差异有统计学意义(P<0.05);随着时间的推移,2组SIA逐渐有减小趋势,但A组SIA仍小于B组,术后3个月差异仍有统计学意义(P<0.05).术后1 d,2组角膜表面非对称性指数(surface asymmetry index,SAI)、角膜表面规则指数(surface regularity index,SRI)均较术前增大,差异有统计学意义(P<0.05),其中A组的SAI、SRI较B组小,差异有统计学意义(P<0.05).术后1周,A组SAI、SRI同术前相比差异无统计学意义(P>0.05);B组SAI、SRI仍比术前高,差异有统计学意义(P<0.05).术后1个月、3个月2组SAI、SRI同术前相比差异均无统计学意义(P>0.05),2组之间各相应时间点SAI、SRI的差异也均无统计学意义(P>0.05).结论 颞侧透明角膜切口操作方便,术后SIA、SAI、SRI均小于上方透明角膜切口,对角膜表面形态的影响小,术后早期视力恢复好.是较理想的手术切口方位.     

非球面和球面人工晶状体植入术后视功能观察

目的 分析白内障患者术前角膜散光情况评估经不同位置透明角膜切口行超声乳化术后的角膜散光变化情况.方法 218例(295只眼)白内障患者分为三组,第一组选择颞侧切口,第二组选择颞上方切口,第三组选择上方切口,三组患者通过透明角膜切口行白内障超声乳化及折叠式后房型人工晶体植入术.术前及术后一周、一月、三月分别检测患者角膜散光情况,并通过Holladay-Cravy-Koch方法 计算术源性散光.结果 术前角膜散光0.5至1.5D的占60.68%,大于等于1.5D的占11.86%,顺归散光占29.49%,逆归散光占51.19%,其余为斜轴散光.术后三次随访颞侧切口组的术源性散光最低,上方切口组的术源性散光最高,具有统计学差异(P<0.05).另外,在上方切口组中发现患者术后角膜散光有向逆归散光转变的趋势.结论 白内障患者术前大多存在小于1.5D的角膜散光.在白内障术后早期阶段,颞侧透明角膜切口引起的术源性散光较小,而上方透明角膜切口不仅可引起较显著的术源性散光,并且术后角膜散光有向逆归散光转变的趋势.

Abstract：

Objective To analyze the corneal astigmatism before cataract surgery and evaluate the astigmatism changes after cataract surgery performed using clear corneal incisions with different locations.Methods: This randomized prospective clinical study comprised 295 eyes of 218 patients having phacoemulsification and implantation of foldable intraocular lens through a corneal tunnel incision. Patients were randomly divided into three groups depending on the different locations of the incision: temporal, superotemporal and superior. Corneal topography was performed preoperatively and 1 week, 1 month, and 3 months postoperatively. Surgically induced changes were calculated by vector analyses using the Holladay-Cravy-Koch method. Results: Preoperatively, in 60.68% of eyes, corneal astigmatism was between 0.5 and 1.5 diopters (D) and in 11.86%, it was 1.5 D or higher. Meanwhile, about 29.49 percent of eyes had with-the-rule (WTR) astigmatism, while 51.19% had against-the-rule (ATR) astigmatism, and the others had oblique astigmatism. At three follow-up visits postoperatively, the mean magnitude of surgically-induced astigmatism (SIA) was lowest in the temporal incision group and highest in the superior incision group. In addition, an ATR shift was found in the superior incision group. Conclusions: Corneal astigmatism less than 1.5 D was present in most cataract surgery candidates. Cataract surgery using temporal clear corneal incision induced significantly less SIA in the early postoperative period. Superior incision may lead to an ATR astigmatism shift.     

透明角膜切口联合对侧单切口角膜缘松解术矫正散光的临床效果

目的动态观察透明角膜切口联合对侧单切口角膜缘松解术对角膜散光的矫正效果。方法选取就诊于我院的白内障患者共68例(76眼),患者术前散光均≥1.5D,随机分为观察组32例(36眼)和对照组36例(40眼),术中观察组在最陡散光轴行透明角膜切口联合对侧单切口角膜缘松解术;对照组在角膜最陡散光轴做成对的角膜缘松解切口,然后按照常规方法进行超声乳化手术。结果所有患者术后散光有了明显的减少,术前与术后的散光值比较,差异有统计学意义(均为P<0.05);术后裸眼视力均有明显的改善,观察组术后3个月视力>0.8的患者占61.1%,对照组占65.0%;观察组与对照组术前散光在1.5～3.0D的患者,术后1d、1周、1个月、3个月的散光值之间比较,差异无统计学意义(均为P>0.05);术前散光>3.0D患者,术后3个月观察组的散光值(1.44±0.41)D与对照组的散光值(1.05±0.36)D比较,差异有统计学意义(t=2.195,P<0.05)。结论采用最陡散光轴的透明角膜切口联合对侧单切口角膜缘松解术与成对的角膜缘松解矫正术前中、低度散光患者具有同样的临床效果,但对于术前高度散光患者后者的效果优于前者。     

Effect of incision size and site on corneal endothelial changes in cataract surgery.

PURPOSE: To compare endothelial damage induced by different cataract incision sites and sizes using specular microscopy. SETTING: Department of Ophthalmology, Hospital of San Donà di Piave, Venice, Italy. METHODS: Eighty-one eyes having phacoemulsification were randomly assigned to 1 of 3 groups of 27 eyes each: 3.5 mm clear corneal incision (CCI) with silicone foldable intraocular lens (IOL) implantation; 5.5 mm sutured CCI with poly(methyl methacrylate) (PMMA) IOL implantation; 5.5 mm scleral tunnel with PMMA IOL implantation. All incisions were centered at the 120-degree semimeridian; that is, they were superotemporal in right eyes and superonasal in left eyes. Noncontact specular microscopy was performed in the center and at the 12 o'clock position preoperatively as well as 1 week and 1, 3, and 12 months postoperatively. The endothelial cell density, mean cell area, cell size variation coefficient, percentage of hexagonality, and corneal thickness were considered. RESULTS: Progressive endothelial cell loss and an increase in mean cell area occurred in all groups during the follow-up. The cell loss percentages relative to the endothelial center appeared similar among the groups and slightly although not significantly lower in the scleral tunnel group. The scleral tunnel group had a statistically significant lower cell loss percentage at the 12 o'clock position than the 2 CCI groups at all follow-ups. CONCLUSIONS: The scleral tunnel group had less postoperative endothelial damage than the 2 CCI groups, with a statistically significant difference at the 12 o'clock position. This is probably because the scleral tunnel incision is placed more posteriorly and therefore induces less direct and indirect endothelial trauma.