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.     

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.     

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.     

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。     

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.     

Comparison of surgically induced astigmatism in chevron,straight, and frown incisions in manual small-incision cataract surgery

Purpose:The study was conducted to calculate and compare the surgically induced astigmatism (SIA) in chevron, frown, and straight incisions in manual small-incision cataract surgery (MSICS).Methods:A prospective, hospital-based study was conducted on 90 patients aged 50 years and above with nuclear sclerosis of grade 4 or more. Each group had 30 patients, divided into Group V (chevron incision), Group S (straight incision), and Group F (frown incision). Patients who had with-the-rule (WTR) astigmatism were operated on through a chevron or straight incision superiorly, while patients who had against-the-rule (ATR) astigmatism underwent MSICS through a temporal frown incision. The patients were followed up post-operatively on days 1, 7, 6 weeks, and 12 weeks, and at each visit, the uncorrected visual acuity (UCVA), best corrected visual acuity (BCVA), and SIA were calculated and compared.Results:The mean age of all the patients was 66.22 ± 8.05 years. BCVA of at least 6/18 or better at 12 weeks post-operatively was achieved in 29 patients (97%) in Group V, 28 patients (93%) in Group F, and 29 patients (97%) in Group S. The mean SIA in Group V was 0.34D ± 0.22D, in Group S was 0.97D ± 0.29D, and in Group F was 0.575D ± 0.25D.Conclusion:SIA by chevron incision is the least followed by the frown incision and straight incision. The superiorly placed chevron incision in WTR astigmatism provided optimal results for the best UCVA and minimal SIA. The temporal frown incision in ATR astigmatism also had good results.     

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.     

上方巩膜切口超声乳化术后角膜散光的改变

目的 研究上方巩膜5.5mm切口白内障超声乳化术后角膜散光的改变。方法 68例70眼白内障,排除其它眼病,术前角膜散光小于2.5D,眼轴长度在20.0～25.5mm之间,用自动角膜曲率仪测量角膜中央3mm内散光。术后10～12月复查,所得数据进行统计学处理(t检验)。结果 角膜逆规性散光组的年龄大于顺规性散光组,(P<0.05)。术后逆规性散光度有所增加(P<0.01),顺规性散光度有所下降。结论 上方巩膜5.5mm切口超声乳化术后会增加逆规性散光度,提示已有逆规性散光者,不宜用上方巩膜切口。     

Surgically induced astigmatism after superotemporal and superonasal clear corneal incisions in phacoemulsification

PURPOSE: To evaluate surgically induced corneal astigmatism after small superotemporal and superonasal clear corneal incision cataract surgery. SETTING: Department of Ophthalmology, School of Medicine, University of Afyon Kocatepe, Afyon, Turkey. METHODS: This prospective study comprised 56 eyes of 28 patients who had bilateral phacoemulsification and implantation of a foldable intraocular lens (IOL) through a corneal tunnel incision. A superotemporal incision was used in all right eyes, and a superonasal incision was used in all left eyes. Topography was performed preoperatively and at 1 week, 1, 3, and 6 months, and 1 year. Surgically induced astigmatism (SIA) was calculated by vector analyses using the Holladay-Cravy-Koch method. The incision length was measured and was between 3.30 mm and 3.50 mm in all eyes. RESULTS: Although SIA did not differ significantly between the 2 incision groups (P>.05), decomposition of vectors showed that the horizontal component of SIA after superonasal incision was statistically significantly higher than superotemporal incision throughout the study (P<.05). Vertical components of SIA and the incision size after IOL implantation with the syringe/cartridge system between the 2 incision groups were not significantly different (P>.05). CONCLUSION: There was no statistically significant difference in SIA between superotemporal incisions in the right eyes and superonasal incisions in the left eyes 1 year after surgery for a surgeon who sits at the 12 o'clock. Superonasal clear corneal incisions can be used in left eyes and superotemporal clear corneal incisions in right eyes.     

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。     

Peripheral corneal relaxing incisions combined with cataract surgery

PURPOSE: To analyze the effectiveness of peripheral corneal relaxing incisions (PCRIs) in correcting corneal astigmatism during cataract surgery. SETTING: Cullen Eye Institute, Baylor College of Medicine, Houston, Texas, USA. METHODS: In 115 eyes of 94 patients (mean age 69 years +/- 12 [SD]), cataract surgery was combined with PCRIs. The PCRIs were created according to a nomogram based on age and preoperative keratometric astigmatism. Postoperative keratometric astigmatism was measured at 1 day and 1 and 4 months. Vector analyses using the Holladay-Cravy-Koch formula and Alpins method were performed. RESULTS: The PCRIs significantly decreased keratometric astigmatism in patients with preexisting with-the rule (WTR) or against-the-rule (ATR) astigmatism and increased the percentage of the eyes with lower keratometric astigmatism in each group. Four months postoperatively in patients with WTR astigmatism, single and paired 6.0 mm PCRIs induced mean with-the-wound minus against-the-wound changes (WTW-ATW) of -0.55 diopter (D) and -1.18 D, respectively. In eyes with ATR astigmatism, the mean WTW-ATW changes induced by single 4.5 mm, single 6.0 mm, and paired 6.0 mm PCRIs were -2.18 D, -2.02 D, and -2.72 D, respectively. These mean WTW-ATW changes did not significantly regress from 1 day to 4 months postoperatively. CONCLUSIONS: Peripheral corneal relaxing incisions were effective in reducing preexisting astigmatism during cataract surgery. A modified nomogram is proposed. The long-term effect of PCRIs should be evaluated.     

Surgically induced astigmatism after phacoemulsification in eyes with mild to moderate corneal astigmatism: temporal versus on-axis clear corneal incisions

PURPOSE: To determine whether there is a difference in surgically induced astigmatism (SIA) and postoperative uncorrected visual acuity (UCVA) and best corrected visual acuity (BCVA) between 2 types of clear corneal incisions used in phacoemulsification: the temporal and the on-axis (ie, on the steeper corneal meridian) clear corneal incision (CCTI and CCOI, respectively). SETTING: Moorfields Eye Hospital, London, United Kingdom. METHODS: In a prospective randomized controlled trial (pilot study), 61 eyes with cataract and mild to moderate corneal astigmatism (<2.58 diopters [D] on corneal topography) having phacoemulsification (single surgeon, 3.2 mm incision) were randomized to receive CCTI or CCOI. Main outcome measures included postoperative BCVA and corneal astigmatism and SIA (calculated using the Holladay vector analysis formula). Measurements were repeated postoperatively at 3 weeks in all eyes, whereas only 46 eyes made it to the final assessment at 8 weeks. Continuous variables between groups were compared by Student t test. The power of the study was calculated. RESULTS: At the first follow-up, the difference in SIA between the 2 incision types was 0.15 D and it was not statistically significant (0.65 D in CCOI; 0.50 D in CCTI). At the second follow-up, the difference was 0.29 D and it was statistically significant (0.63 D in CCOI; 0.34 D in CCTI; P = .0004). There was no statistically significant difference in the final postoperative visual acuity. The power of the pilot study was 72%. CONCLUSION: Seven weeks after small-incision phacoemulsification, the CCTI induced less SIA than the CCOI; however, there were no significant differences in the final UCVA and BCVA.     

Optimal incision sites to obtain an astigmatism-free cornea after cataract surgery with a 3.2 mm sutureless incision.

PURPOSE: To determine the optimal incision to eliminate astigmatism after cataract extraction. SETTING: Hara Eye Hospital, Utsunomiya, Japan. METHODS: Patients having cataract extraction through a 3.2 mm corneal limbal incision without limbal sutures were divided into 2 groups. Group 1 comprised 98 eyes of 80 patients without preoperative astigmatism and Group 2, 72 eyes of 62 patients with no astigmatism postoperatively. In Group 1, the incisions that caused postoperative corneal changes were retrospectively evaluated. In Group 2, the types of incisions that induced an astigmatism-free cornea postoperatively were retrospectively studied. Patients were examined preoperatively and 6 months postoperatively. RESULTS: In Group 1, 23 of 40 eyes (57.5%) with an incision between 9 and 12 o'clock (BENT incision) and 10 of 58 eyes (17.2%) with an incision at 12 o'clock remained astigmatism free postoperatively (P <.0001). One eye (2.5%) with a BENT incision and 17 (29.3%) with a 12 o'clock incision had astigmatism greater than 1.0 diopter (D) postoperatively (P <.001). In Group 2, 72 eyes had less than 1.2 D of preoperative astigmatism. No eye with more than 1.2 D of astigmatism was astigmatism free postoperatively, even when the incision was made at the steepest meridian. CONCLUSIONS: The results indicate that to reduce astigmatism in eyes with preoperative astigmatism of 0.5 D or more, a limbal 3.2 mm BENT incision should be placed at 10:30 o'clock. To prevent astigmatism postoperatively, the incision should be placed at the steepest meridian in eyes with preoperative astigmatism greater than 0.5 D; for preoperative astigmatism greater than 1.2 D, a 3.2 mm incision at the corneal limbus is insufficient and a wider incision or an additional incision is required.     

Effect on astigmatism of the location of clear corneal incision in phacoemulsification of cataract

PURPOSE: To investigate the refractive results of clear corneal incision performed at the steepest meridian of pre-existing corneal astigmatism. METHODS: One hundred eighty-two patients with astigmatism > 0.75 diopters (D) were evaluated. Superior, temporal, nasal, superotemporal, or superonasal clear corneal incisions were performed at the steep meridian. Refraction, visual acuity, and topography values were evaluated, and changes in surgically induced astigmatism were calculated by vector analysis using the Fourier formula. Paired t test was used to compare mean values. RESULTS: Postoperative cylinder values showed minor changes in all groups, except the nasal group. Nasal incision increased preoperative cylinder from 1.13 D to 1.83 D 6 months after surgery. Temporal and superotemporal incisions resulted only in small astigmatic changes. Conversely, superior, superonasal, and nasal incisions induced more pronounced astigmatism. CONCLUSIONS: Performing clear corneal incision for phacoemulsification of cataract at the steep meridian resulted in small changes with temporal incisions, whereas nasal incisions resulted in higher surgically induced astigmatism.     

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。     

OCCI与TCCI手术切口植入Acrysof Toric人工晶状体的临床对比研究

目的 比较两种不同位置角膜切口对Acrysof Toric人工晶状体(IOL)植入准确性和散光矫正能力的影响.方法 前瞻性研究.选择年龄相关性白内障伴角膜散光患者25例(39只眼),散光度数为1.00～2.26 D,行超声乳化白内障吸除联合Acrysof Toric IOL植入术,术中分别采用陡峭轴(即角膜的最大曲率径线)角膜切口(OCCI)即OCCI组(20只眼)或颞侧角膜切口(TCCI)即TCCI 组(19只眼),比较两组患者术后3个月的裸眼视力、最佳矫正视力、角膜曲率、手术源性散光值、IOL 轴位偏差、散光矫正指数以及植入准确性.统计学方法采用t检验和Z检验.结果 术后角膜散光改变比较,OCCI组减小(0.31±0.26)D,而TCCI组增加(0.28±0.27)D,差异有统计学意义(t=5.756,F=0.000).IOL轴位偏差比较,OCCI组为0°±0°,而TCCI组为2.22°±2.99°,差异有统计学意义(t=3.860,P=0.000).手术矫正散光指数比较,分别为1.04±0.27和0.59±0.44,差异有统计学意义(t=3.187,P=0.004).散光矫正的准确性比较,分别为0.838和0.484,差异有统计学意义(Z=1.970,P=0.049).结论 与TCCl相比,OCCI提高了Acrysof Toric IOL植入的准确性和矫正散光的能力.     

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.     

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.