1.Effect of Experimental Scleral Shortening on Axial Length of the Rabbit Eye.
Han Sang PARK ; Jung Yeal KIM ; Jae Pil SHIN ; Yul Je CHOI ; Si Yeol KIM
Korean Journal of Ophthalmology 2005;19(2):101-105
PURPOSE: To evaluate the change of axial length (AL), intraocular pressure (IOP), and corneal astigmatism after scleral shortening with scleral invagination in the rabbit eye. METHODS: The authors performed scleral shortening (3 mm) with scleral invagination in two groups of 6 eyes each: 180 degrees (group 1) and 360 degrees (group 2). RESULTS: Average AL shortening was more prominent in group 2 (0.5 +/- 0.17 mm) than in group 1 (0.37 +/- 0.29 mm), but the difference was not statistically significant. IOP increased immediately after the procedure and was maintained at a high level through 2 months postoperatively. Induced corneal astigmatism was more prominent in group 1 than in group 2. The difference was statistically significant in group 1 (p< 0.05) but not in group 2. CONCLUSIONS: In the scleral shortening with scleral invagination procedure, a large amount of scleral invagination resulted in more shortening of axial length, but there was more corneal astigmatism in 180-degree invagination of the sclera than in 360-degree. Further research is required to determine the effect of the extent of scleral invagination on the change of these values.
Animals
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Astigmatism/*etiology
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Corneal Diseases/*etiology
;
Eye/*pathology
;
*Intraocular Pressure
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Postoperative Period
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Rabbits
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Sclera/*surgery
2.Comparison of Surgically Induced Astigmatisms after Clear Corneal Incisions of Different Sizes.
Sung Chur MOON ; Tarek MOHAMED ; I Howard FINE
Korean Journal of Ophthalmology 2007;21(1):1-5
PURPOSE: This study was performed to assess efficiency and stability of astigmatic change by incision size after cataract surgery. METHODS: This work was designed as a retrospective, comparative, nonrandomized interventional study. A total of 121 cases of cataract surgery were reviewed in 98 patients performed by one surgeon at the Oregon Eye Institute in Eugene, OR, USA with 3-year follow-ups. All procedures were performed with the temporal approach of self-sealing incisions. The serial change in surgically induced astigmatisms were examined in all cases of three groups: Group A, cartridge injection of a foldable IOL through a 2.5 mm self-sealing incision; Group B, cartridge injection of a foldable IOL through a 3.0 mm self-sealing incision; Group C, cartridge injection of a foldable IOL through a 3.5 mm self-sealing incision. Keratometric data were obtained preoperatively, and 3 weeks, 3 months, 6 months, 9 months, 12 months, 24 months and 36 months postoperatively. Polar value analysis was performed to calculate the surgically induced astigmatism. RESULTS: The astigmatic change decreased over time in Group B (P<0.05). The other groups tended to remain in induced astigmatism. All groups showed anticlockwise torque at 3 weeks following surgery. Group B showed a decrease in deviation, but the other groups showed increases in their torque value at postoperative 12 months (P<0.05). CONCLUSIONS: The 3.0 mm incision size correlated with the least surgically induced astigmatism.
Retrospective Studies
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Phacoemulsification
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Lens Implantation, Intraocular
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Humans
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Cornea/*surgery
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Cataract Extraction/*adverse effects/*methods
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Astigmatism/*etiology
3.Surgically-induced corneal changes following macular translocation with punctate retinotomies and chorioscleral infolding (limited macular translocation).
James C H PAN ; Wee-Jin HENG ; Kah-Guan Au EONG
Annals of the Academy of Medicine, Singapore 2006;35(8):588-590
INTRODUCTIONTo report the sequential changes in corneal topography and astigmatism following limited macular translocation. CLINICAL PICTURE AND TREATMENT: A 45-year-old-man who underwent limited macular translocation for idiopathic subfoveal choroidal neovascularisation in the right eye was evaluated by corneal topography and manifest refraction preoperatively and serially for 1 year postoperatively.
OUTCOMEAn increase in astigmatism with corneal steepening along meridians corresponding to the area of chorioscleral infolding was observed and this persisted for 1 year after surgery. Vector-analysed astigmatic change showed significant surgically induced astigmatism of 2.18 dioptres (D) X 52.9 degrees, 2.17 D X 57.8 degrees and 2.56 D X 59.1 degrees at 2, 5 and 12 months after surgery respectively.
CONCLUSIONSurgically induced corneal changes are evident after limited macular translocation and may remain up to 1 year after surgery.
Astigmatism ; etiology ; Choroidal Neovascularization ; surgery ; Corneal Diseases ; etiology ; Corneal Topography ; Humans ; Male ; Middle Aged ; Ophthalmologic Surgical Procedures ; adverse effects
4.Perioperative Modulating Factors on Astigmatism in Sutured Cataract Surgery.
Korean Journal of Ophthalmology 2009;23(4):240-248
PURPOSE: To evaluate the factors that affect postoperative astigmatism and post-suture removal astigmatism, and to evaluate the risk factors associated with astigmatism axis shift. METHODS: We performed a retrospective chart review of 130 eyes that had undergone uneventful phacoemulsification cataract surgery. Preoperative astigmatism was divided into four groups (Groups I, II, III, and IV) according to the differences between the axis of preoperative astigmatism (flattest axis) and the incision axis (105 degrees). We analyzed the magnitude and axis of the induced astigmatism after the operation and after suture removal in each group. We also analyzed the factors which affected the postoperative astigmatism and post-suture removal astigmatism in each sub-group of Groups I, II, III, and IV, excluding postoperative or post-suture removal axis shift (specifically, Group I(WAS), II(WAS), III(WAS), and IV(WAS)). We identified the variables associated with the prevalence of postoperative astigmatism axis shift and those associated with the prevalence of post-suture removal axis shift. RESULTS: An increase in the magnitude of postoperative astigmatism was associated with an increase in the preoperative magnitude of astigmatism in Groups I(WAS), II(WAS), and III(WAS) (p<0.05), and with an increase in the corneal tunnel length in Group I(WAS). A decrease in the magnitude of postoperative astigmatism was associated with an increase in the corneal tunnel length in Groups III(WAS) and IV(WAS) (p<0.05). An increase in the magnitude of post-suture removal astigmatism was associated with an increase in the magnitude of postoperative astigmatism in Groups I(WAS) and IV(WAS) (p<0.05), and with late suture removal in Group IV(WAS) (p<0.05). A decrease in the magnitude of post-suture removal astigmatism was associated with late suture removal in Groups I(WAS) and II(WAS). A logistic regression analysis showed that the prevalence of post-suture removal astigmatism axis shift was associated with increased corneal tunnel length, decreased magnitude of postoperative astigmatism, and early suture removal. CONCLUSIONS: In order to reduce postoperative and post-suture removal astigmatism, we recommend a short corneal tunnel length and late suture removal in patients with Group I(WAS) characteristics, late suture removal in Group II(WAS)-like patients, long corneal tunnel length in Group III(WAS)-like patients, and long corneal tunnel length and early suture removal in patients with characteristics of Group IV(WAS).
Astigmatism/etiology/*prevention & control
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Cataract Extraction/*methods
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Follow-Up Studies
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Humans
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Postoperative Complications/etiology/prevention & control
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Retrospective Studies
;
*Suture Techniques
5.Transient Increase of Higher-Order Aberrations after Lateral Rectus Recession in Children.
Kyoung Yul SEO ; Samin HONG ; Won Kyoung SONG ; Seung Ah CHUNG ; Jong Bok LEE
Yonsei Medical Journal 2011;52(3):527-529
The changes of higher-order aberrations (HOAs) after bilateral lateral rectus muscle recession were evaluated. Forty eyes of 20 children were enrolled and their wavefront information was assessed until postoperative 3 months. Even though the root mean square (RMS) of total aberration was not changed, the RMS of HOA was transiently increased at postoperative 1 week and returned to baseline level after 1 month. Among individual Zernike coefficient, secondary astigmatism, quadrafoil, secondary coma, secondary trefoil, and pentafoil showed similar tendency with the RMS of HOA. However, coma, trefoil, and spherical aberration were not changed. Regarding recession amount, it did not correlate with any Zernike coefficient. In summary, our data imply that the HOAs are transiently increased after lateral rectus recession surgery. These results are in collusion with previous reports that strabismus surgery induced transient corneal astigmatism.
Adolescent
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Astigmatism/*etiology
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Child
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Child, Preschool
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Exotropia/*surgery
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Female
;
Humans
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Male
;
Postoperative Care
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*Postoperative Complications/epidemiology/pathology
;
Vision Tests
6.A Comparison of the Efficacy of Cataract Surgery Using Aqualase(R) with Phacoemulsification Using MicroFlow(R) System.
Hyun Wook RYU ; Shin Hae PARK ; Choun Ki JOO
Korean Journal of Ophthalmology 2007;21(3):137-141
PURPOSE: To compare the outcomes after phacoemulsification performed with the AquaLase(R) and phacoemulsification in MicroFlow(R) system, including surgically induced astigmatism (SIA), corneal endothelial cell damage and postoperative recovery of visual acuity. METHODS: The cataracts of Lens Opacities Classification System, version III (LOCS III) nuclear grade below 2 were subjected in this study. Nineteen eyes underwent cataract operation using AquaLase(R) (Alcon Laboratories, Fort Worth, Texas, U.S.A.). A control group (19 eyes) used the MicroFlow(R) system (Millenium, Stortz, U.S.A.) and was selected by matching age, sex, systemic disease, corneal astigmatism and corneal endothelial cell density. All the surgeries were performed by the same operator. SIA, corneal endothelial cell loss, visual acuity, and corneal thickness were evaluated postoperatively. RESULTS: SIA in the group using AquaLase(R) was less than that of the group using MicroFlow(R) system (P=0.022) at 2 months postoperatively. Evaluation of corneal endothelial cell loss, recovery of visual acuity and corneal thickness found no statistically significant differences between the two groups. CONCLUSIONS: Cataract surgery using AquaLase(R) induces less surgically induced astigmatism in mild to moderate cataracts.
Astigmatism/etiology
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Cataract Extraction/adverse effects/*methods/*standards
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Humans
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Phacoemulsification/adverse effects/*standards
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Prospective Studies
;
Treatment Outcome
7.The Effect of Epiblepharon Surgery on Visual Acuity and With-the-Rule Astigmatism in Children.
Na Mi KIM ; Jae Ho JUNG ; Hee Young CHOI
Korean Journal of Ophthalmology 2010;24(6):325-330
PURPOSE: To evaluate the effect of epiblepharon surgery on visual acuity and with-the-rule astigmatism in children compared to patients without surgical treatment. METHODS: We undertook a retrospective case control study and reviewed the charts of 202 eyes treated with epiblepharon surgery and of 142 eyes without surgery. The surgical procedure for epiblepharon correction used rotating suture techniques. Data regarding age, best corrected visual acuity, and degree of astigmatism were recorded. Baseline and 1-, 3-, 6-, and 12-month postoperative data were collected. The chi-square test, Student's t-test and general linear model analysis for repeated measures were applied. RESULTS: The mean astigmatism in the surgical group decreased from 1.10 +/- 1.02 diopter (D) preoperatively to 0.84 +/- 1.05 D at 3 months after surgery (p < 0.05). However, there was no statistically significant difference compared to the non-surgical group during the first year. The general linear model analysis comparing the mean astigmatism between the two groups over time showed a significant group-time interaction (p < 0.05). Within the surgical group, the higher baseline astigmatic subgroup and the 5- to 8-year-old group demonstrated greater cylinder reduction over time. The change in mean visual acuity was not significant in either group. CONCLUSIONS: Significant astigmatic reduction was found after surgical correction in epiblepharon patients. Patients with higher baseline astigmatism exhibited greater astigmatic reduction after epiblepharon surgery. These results suggest that, in order to reduce astigmatism, an epiblepharon operation should be considered in patients with a high level of astigmatism.
Astigmatism/*etiology/*physiopathology
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Case-Control Studies
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Child
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Child, Preschool
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Eye Abnormalities/*complications/*surgery
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Eyelashes/pathology
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Eyelids/*abnormalities/pathology/surgery
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Female
;
Humans
;
Male
;
Retrospective Studies
;
Treatment Outcome
;
*Visual Acuity
8.Postoperative Astigmatic Outcomes Based on the Haptic Axis of Intraocular Lenses Inserted in Cataract Surgery.
In Tae KIM ; Hae Young PARK ; Hyun Seung KIM
Korean Journal of Ophthalmology 2011;25(1):22-28
PURPOSE: This study was conducted to compare post-operative astigmatic outcomes of two groups, with-the-rule (WTR) and against-the-rule (ATR) astigmatism patients, according to the haptic axis of intraocular lenses (IOLs) inserted in cataract surgery. METHODS: Seventy-two eyes with WTR astigmatism and 79 eyes with ATR astigmatism had cataract surgery through a clear corneal temporal incision. These two groups of eyes were then each divided into 2 groups based on whether the haptic axis of the inserted IOL was at 180degrees or 90degrees. For ATR patients, the outcomes were analyzed according to the three types of IOLs. RESULTS: There was no difference in corneal astigmatism, but WTR patients with a 180degrees haptic axis of the inserted IOL and ATR patients with a 90degrees hepatic axis of the inserted IOL had a significant decrease in postoperative refractive astigmatism (p < 0.05). The changes in ATR astigmatism according to the IOL type were more effective in single-piece acrylic IOLs than in the three-piece polymethylmethacrylate haptic IOL group. CONCLUSIONS: Insertion of the IOL at the 180degrees haptic axis in WTR patients and at 90degrees in ATR patients during cataract surgery may have an effect in reducing pre-existing astigmatism. This observed effect was not consistent among the different types of IOLs.
Astigmatism/classification/*etiology/*physiopathology
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Cataract Extraction/*adverse effects
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Equipment Design
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Humans
;
Lens Implantation, Intraocular/*methods
;
*Lenses, Intraocular
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*Postoperative Complications
;
Treatment Outcome
9.The Effect of Different Suturing Techniques on Astigmatism after Penetrating Keratoplasty.
Sang Jin KIM ; Won Ryang WEE ; Jin Hak LEE ; Mee Kum KIM
Journal of Korean Medical Science 2008;23(6):1015-1019
The purpose of this study was to compare the effects on astigmatism after penetrating keratoplasty with three different suture techniques. In this prospective study, 38 eyes of 38 patients underwent penetrating keratoplasty with three suturing techniques: interrupted, single running, and double running. Topographic astigmatism was measured at 2, 6, 12, and 18 months after keratoplasty. During 18 months after surgery, the interrupted suture group had higher astigmatism than the double running suture group. There was no significant difference in the amounts of astigmatism during the first year after keratoplasty between the single running and the double running suture group. However, at 18 months after surgery, when all sutures were out, the double running suture group (3.60+/-1.58 diopters) showed significantly less astigmatism than the single running group (5.65+/-1.61 diopters). In conclusion, post-keratoplasty astigmatism was the least in the double running suture group of the three suturing techniques at 18 months after penetrating keratoplasty.
Adult
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Astigmatism/etiology/*prevention & control
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Corneal Diseases/surgery
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Corneal Topography
;
Female
;
Humans
;
*Keratoplasty, Penetrating
;
Male
;
Middle Aged
;
Postoperative Complications
;
Prospective Studies
;
*Suture Techniques
;
Time Factors
;
Visual Acuity
10.Pseudophakic Residual Astigmatism.
Jung Gn BAE ; Sung Jin KIM ; Young In CHOI
Korean Journal of Ophthalmology 2004;18(2):116-120
We investigated pseudophakic residual astigmatism in order to minimize postoperative refractive astigmatism. We examined 110 eyes of 87 patients who had undergone phacoemulsification with small incision and posterior chamber intraocular lens (IOL) implantation. Corneal astigmatism was measured using an autokeratometer (RK-5, canon), refractive astigmatism by manifest refraction, and residual astigmatism by vector analysis. Mean pseudophakic residual astigmatism was +0.47 X 176degrees, predominantly against-the-rule. Variations of pseudophakic residual astigmatism according to sex, age and IOL type were not statistically significant. When performing cataract surgery as refractive surgery, we may consider that pseudophakic residual astigmatism is approximately 0.50D against-the-rule.
Adult
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Aged
;
Aged, 80 and over
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Astigmatism/diagnosis/*etiology
;
Comparative Study
;
Female
;
Humans
;
*Lens Implantation, Intraocular
;
Lenses, Intraocular
;
Male
;
Middle Aged
;
*Phacoemulsification
;
*Postoperative Complications
;
Postoperative Period
;
Pseudophakia/diagnosis/*etiology
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Refraction, Ocular
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Retrospective Studies