The purpose of this study is to assess the efficacy of the multi-zone cross-cylinder method as compared with the single method for astigmatism correction using LASIK. This prospective study enrolled 40 patients (52 eyes) who underwent the cross-cylinder method using LASIK, and 52 patients (60 eyes) who underwent the single method using LASIK: all patients were given a diagnosis of complex myopic astigmatism from the department of ophthalmology of this hospital between January 2002 and July 2003. Preoperatively, the mean spherical equivalent refraction was .3.85 +/- 1.13 D in the cross-cylinder group and .4.05 +/-1.20 D in the single method group (p = 0.23). The mean cylinder was .2.05 +/-1.58 D in the cross-cylinder group and .1.95 +/-1.12 D in the single method group (p = 0.31). 6 months after treatment the results were a mean spherical equivalent refraction of .0.26 +/-0.30 D in the crosscylinder group and -0.34 +/-0.35 D in the single method group (p = 0.13). The mean cylinder was .0.38 +/-0.29 D in the cross-cylinder group and .0.45 +/-0.30 D in the single method group (p = 0.096). There were no statistically significant differences between the two groups. The mean BCVA was not different from mean preoperative BCVA in both groups (i.e., 0.98 +/-0.10, 0.96 +/-0.25, p = 0.86). Postoperatively, patient complications that included night halo, glare and corneal haze were not noted in either group. In conclusion, the results of cross-cylinder method are no different from the single method for the correction of a complex astigmatism. In the future, studies will have to be conducted to assess the efficacy of the cross-cylinder method in consideration of those factors that can affect the postoperative outcome.
Adult ; Astigmatism/*surgery ; Corneal Stroma/surgery ; Humans ; Keratomileusis, Laser In Situ/*methods ; Myopia/*surgery ; Postoperative Complications ; Prospective Studies

OBJECTIVETo evaluate the static and dynamic contrast sensitivity changes in myopic patients before and after laser in situ keratomileusis (LASIK).

METHODSSeventy-three eyes in 37 patients with myopia (with or without astigmatism) who received LASIK were tested for static and dynamic contrast sensitivities using the METRO VISION MON ELEC I system at 0.7, 1.4, 2.7, 5.5, 11, and 22 cpd and cps prior to LASIK, and at one-, three-, and six-month intervals after LASIK.

RESULTSAll eyes gained naked visual acuity of more than 0.5 after LASIK. The contrast sensitivity was depressed at all frequencies 1 month after LASIK, as compared to one week prior to LASIK. The depression at 2.7, 5.5, 11 (P < 0.01) and 22 cpd (P < 0.05) was statistically significant for static contrast sensitivity, and also at 5.5 (P < 0.01) and 11 cps (P < 0.05) for dynamic contrast sensitivity. Myopic eyes between 6.25 D and 14.0 D, and astigmatic eyes 2 DC and more, suffered more static and dynamic contrast sensitivity depression than the myopic eyes between 1.25 D and 6.00 D and astigmatic eyes less than 2 DC. Contrast sensitivities were improved and exceeded preoperative levels 3 months after LASIK, and improved even more 6 months after LASIK. All sequences were statistically significant for static contrast sensitivity (P < 0.01), while only 2.7, 5.5, and 11 cps were statistically significant for dynamic contrast sensitivity (P < 0.01). The astigmatic eyes 2 DC and more showed less improvement, even below the preoperative level at 1.4 cps of dynamic contrast sensitivity.

CONCLUSIONSWhile temporary depression of contrast sensitivity for myopic eyes after LASIK was seen, contrast sensitivity soon returned to exceed preoperative levels at 3 months after LASIK, while improving even more 6 months after LASIK.

Adolescent ; Adult ; Astigmatism ; surgery ; Contrast Sensitivity ; Cornea ; surgery ; Female ; Humans ; Keratomileusis, Laser In Situ ; Male ; Myopia ; physiopathology ; surgery ; Visual Acuity

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 ; Phacoemulsification ; Lens Implantation, Intraocular ; Humans ; Cornea/*surgery ; Cataract Extraction/*adverse effects/*methods ; Astigmatism/*etiology

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 ; Astigmatism/*etiology ; Corneal Diseases/*etiology ; Eye/*pathology ; *Intraocular Pressure ; Postoperative Period ; Rabbits ; Sclera/*surgery

We performed prospective study evaluating surgically-induced alterations in corneal curvature resulting from filtering surgery using the data obtained by corneal topographic analysis. The operation was performed on 12 eyes of 11patients by one operator with the same method. Preoperatively and 6 times postoperatively, we measured vision, axial length, and intraocular pressure and also performed refraction, keratometry and corneal topography. Keratometry showed against-the-rule astigmatic change by corneal topography, five of twelve eyes developed with-the-rule atigmatism. Three patients including two cases combined with phacoemulsification developed against-the-rule astigmatism. Quantitative descriptors of corneal topography such as SAi(surface asymmetry index), SRI(surface regularity index), and Sim K(simulated keratometry value) indicated increase in corneal stability as time went by. In conclusion, compared with keratometry, corneal topography was more valuable in evaluating corneal change following trabeculectomy in that it correctly indentified the amount of astigmatism and could provide information on peripheral corneal change.
Astigmatism ; Corneal Topography* ; Filtering Surgery ; Humans ; Intraocular Pressure ; Phacoemulsification ; Prospective Studies ; Subject Headings ; Trabeculectomy

The effectiveness of excimer laser photorefractive keratectomy (PRK) for astigmatism was evaluated. We treated 136 eyes of naturally occurring myopic astigmatism using the 193-nm excimer laser with an expanding slit and an iris diaphragm, and followed for a minimum of 6 months. At 6 months after operation, the mean refractive cylinder decreased from 1.62 +/- 0.88 D preoperatively to 0.48 +/- 0.48 D. For detailed analysis of the results, the surgically induced refractive change (SIRC) was determined from the preoperative and postoperative refractions by vector analysis of astigmatism. When we compared the cylinder of the SIRC with the preoperative refractive cylinder, the effect of the cylindrical ablation was 93.9 +/- 36.7% at 6 months. The axial error of the cylinder of the SIRC to the preoperative cylindrical axis was 5.9 +/- 10.2 degrees at 6 months. These results suggest that excimer laser PRK with an expanding slit appears to have a significant effect for the correction of astigmatism.
Adult ; Astigmatism/*surgery ; Cornea/*surgery ; Female ; Follow-Up Studies ; Humans ; *Laser Therapy ; Male ; Middle Aged ; Treatment Outcome ; Visual Acuity

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 ; Astigmatism/*etiology ; Child ; Child, Preschool ; Exotropia/*surgery ; Female ; Humans ; Male ; Postoperative Care ; *Postoperative Complications/epidemiology/pathology ; Vision Tests

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

Transverse incision astigmatic keratotomy procedures were performed, combined with radial keratotomy, in 16 eyes for correction of astigmatism and coexisting myopia. We used a transverse incision technique in which T-incisions vertically intersected radial incisions of the steepest corneal meridian. After a mean follow-up period of 10 months with a range of six to 27 months, an average 1.92 diopters of the cylinder was corrected. In comparison with 2.11 diopters of the cylinder corrected at postoperative one day, there was a 22.8% decrease in the effect of astigmatism correction after a postoperative period averaging 10 months.
Adolescent ; Adult ; Astigmatism/complications/*surgery ; Female ; Follow-Up Studies ; Humans ; Keratotomy, Radial/*methods ; Male ; Middle Aged ; Myopia/complications/surgery ; Refraction, Ocular ; Visual Acuity

Anterior radial keratotomy for high myopia (over-6.25 diopter) to reduce refractive error was not able to dispense with glasses or contact lenses due to the high myopia itself. However patients could see objects well and were free of dizziness while wearing glasses of relatively reduced power. We performed anterior radial keratotomies on 83 high myopic and/or astigmatic eyes of 47 patients at Kangnam St. Mary's Hospital between May 1990 and Mar. 1991. Eight radial incisions with a diamond blade were performed and the Ruiz technique was added for astigmatism of over 2.0 diopters. The depth of incision was 90 to 95% of corneal thickness and the optical zone was 3mm in diameter. Patients were followed up on postoperative 7 days. 1 month, 3 months, 6 months, 1 year and thereafter. Uncorrected visual acuity of 20/40 or better after radial keratotomy could be obtained in 19.6% of high myopic eyes. A mean reduction of the spherical equivalent cycloplegic refraction of 5.13 diopters and a keratometric reading of 3.89 diopters after radial keratotomy were observed. About 90% of patients were satisfied with their visual outcome with reduced refractive power glasses. We recommend radial keratotomy for high myopic patients to reduce the refractive power and to help them enjoy a more comfortable life.
Adolescent ; Adult ; Astigmatism/surgery ; *Eyeglasses ; Female ; Follow-Up Studies ; Humans ; Keratotomy, Radial/*methods ; Male ; Middle Aged ; Myopia/*surgery ; Treatment Outcome ; Visual Acuity