PURPOSE: To investigate the changes in corneal higher-order aberration (HOA) during amblyopia treatment and the correlation between HOA and astigmatism in hyperopic amblyopia children. METHODS: In this retrospective study, a total of 72 eyes from 72 patients ranging in age from 38 to 161 months were included. Patients were divided into two groups based on the degree of astigmatism. Corneal HOA was measured using a KR-1W aberrometer at the initial visit and at 3-, 6-, and 12-month follow-ups. Correlation analysis was performed to assess the association between HOA and astigmatism. RESULTS: A total of 72 patients were enrolled in this study, 37 of which were classified as belonging to the higher astigmatism group, while 35 were assigned to the lower astigmatism group. There was a statistically significant difference in success rate between the higher and lower astigmatism groups. In both groups, all corneal HOAs were significantly reduced during amblyopia treatment. When comparing the two groups, a significant difference in coma HOA at the 12-month follow-up was detected (p = 0.043). In the Pearson correlation test, coma HOA at the 12-month follow-up demonstrated a statistically significant correlation with astigmatism and a stronger correlation with astigmatism in the higher astigmatism group than in the lower astigmatism group (coefficient values, 0.383 and 0.284 as well as p = 0.021 and p = 0.038, respectively). CONCLUSIONS: HOA, particularly coma HOA, correlated with astigmatism and could exert effects in cases involving hyperopic amblyopia.
Aberrometry ; Adolescent ; Amblyopia/*physiopathology ; Astigmatism/*physiopathology ; Child ; Child, Preschool ; Corneal Topography ; Corneal Wavefront Aberration/diagnosis/*physiopathology ; Eyeglasses ; Follow-Up Studies ; Humans ; Hyperopia/*physiopathology/therapy ; Retrospective Studies ; Visual Acuity/physiology

PURPOSE: The purpose of this multi-institute, single-group clinical trial was to evaluate the effectiveness and safety of toric orthokeratology lenses for the treatment of patients with combined myopia and astigmatism. METHODS: A total of 44 patients were included in this clinical trial. The patients ranged in age from 7 to 49 years, with myopia of -0.75 to -6.0 diopters (D) and astigmatism of 1.25 to 4.0 D. After excluding 21 subjects, 23 subjects (39 eyes) were analyzed after toric orthokeratology lens use. The subjects underwent ophthalmologic examination after 1 day and 1, 2, 3, and 4 weeks of wearing overnight toric orthokeratology lenses. RESULTS: A total of 19 subjects (31 eyes) completed the trial after five subjects (eight eyes) dropped out. In the patients who completed the study by wearing lenses for 4 weeks, the myopic refractive error decreased significantly by 2.60 ± 2.21 D (p < 0.001), from -3.65 ± 1.62 to -1.05 ± 1.64 D. The astigmatic refractive error were also significantly decreased by 0.63 ± 0.98 D (p = 0.001), from 2.07 ± 0.83 to 1.44 ± 0.99 D. The mean uncorrected and corrected visual acuities before wearing the lenses were 2.14 ± 0.80 logarithm of the logMAR (logMAR) and 0.05 ± 0.13 logMAR, respectively, which changed to 0.12 ± 0.30 logarithm of the logMAR (p < 0.001) and 0.01 ± 0.04 logMAR (p = 0.156) after 4 weeks. No serious adverse reactions were reported during the clinical trial. CONCLUSIONS: Our results suggest that toric orthokeratology is an effective and safe treatment for correcting visual acuity in patients with combined myopia and astigmatism.
Adolescent ; Adult ; Astigmatism/complications/diagnosis/*therapy ; Child ; Cornea/*diagnostic imaging ; Female ; Humans ; Male ; Middle Aged ; Myopia/complications/diagnosis/*therapy ; Orthokeratologic Procedures/*methods ; Slit Lamp Microscopy ; Treatment Outcome ; *Visual Acuity ; Young Adult

PURPOSE: To investigate the biometric risk factors for corneal surface complications associated with hydrogel soft contact lens (SCL) fitting in myopic patients in Korea. METHODS: This is a retrospective case-control study. The records of 124 subjects (124 eyes) who wore SCLs on a daily basis were reviewed. Thirty-one patients (31 eyes) who were diagnosed with corneal neovascularization (NV) while wearing SCLs were included in the complication group. Ninety-three age- and sex-matched patients (93 eyes) who wore SCLs, who did not have corneal NV and who visited our clinic for correction of refractive errors were included in the control group. The degree of spherical equivalent, astigmatism and corneal base curve radius (BCR) were compared in both groups. RESULTS: Patients with NV exhibited poorer best corrected visual acuity and more myopia than controls (p = 0.008 and 0.006, respectively). In univariate analysis, highly myopic patients (-9 diopters [D] or higher) were more likely to experience NV (odds ratio [OR], 2.232; 95% confidence interval [CI], 1.602 to 3.105). High astigmatism (> or =2 D) increased the risk of complications (OR, 2.717; 95% CI, 1.141 to 6.451). Steep cornea, in which BCR was <7.5 mm, also raised the risk of complications (OR, 4.000; 95% CI, 1.661 to 9.804). Flat cornea was not a risk factor for the development of NV. CONCLUSIONS: High myopia, high astigmatism, and steep cornea seemed to be risk factors in the development of corneal NV in SCL wearers.
Adult ; Astigmatism/diagnosis ; Biometry ; Case-Control Studies ; Contact Lenses, Hydrophilic/*adverse effects ; Corneal Neovascularization/diagnosis/*etiology ; Female ; Humans ; Hydrogel ; Male ; Myopia/diagnosis/*therapy ; Prosthesis Fitting ; Retrospective Studies ; Risk Factors ; Visual Acuity

PURPOSE: To evaluate the clinical effects of excimer laser refractive surgery on eyes with residual refractive error after implantation of ReSTOR(R) multifocal intraocular lenses. METHODS: We retrospectively reviewed the medical records of 10 eyes of 6 patients who had undergone cataract surgery with implantation of multifocal intraocular lenses. Photorefractive keratectomy (PRK) (5 eyes) and laser-assisted in situ keratomileusis (LASIK) (5 eyes) was performed on 10 eyes with residual refractive error. RESULTS: After cataract surgery and before laser surgery, the mean spherical equivalent (SE) was -0.34 +/- 0.89 D and the mean astigmatism was 2.08 +/- 0.55 D. Six months after laser surgery, the mean SE was -0.33 +/- 0.30 D (p = 0.354) and the mean astigmatism was 0.23 +/- 0.28 D. The changes in astigmatism between paired preoperative and postoperative values were statistically significant (p < 0.0001). At 6 months after surgery, uncorrected distance visual acuity significantly improved to 0.11 +/- 0.10 (log MAR) (p < 0.0001) There were no significant changes in the best corrected distance visual acuity and uncorrected near visual acuity (p = 0.073, p = 0.100). CONCLUSIONS: On the basis of predictability and stability, excimer laser surgery appears to be a clinically useful procedure to correct residual refractive error after implantation of ReSTOR(R) multifocal intraocular lenses.
Astigmatism ; Cataract ; Eye ; Humans ; Keratomileusis, Laser In Situ ; Laser Therapy ; Lasers, Excimer ; Lenses, Intraocular ; Medical Records ; Photorefractive Keratectomy ; Refractive Errors ; Refractive Surgical Procedures ; Retrospective Studies ; Visual Acuity

PURPOSE: To compare the effect of astigmatism correction upon Mel 80 excimer laser surgery with or without an eye registration system. METHODS: This retrospective analysis investigates a group (eye registration group) of surface laser ablation surgeries for myopic astigmatism correction, with operation on 27 eyes from 15 patients with guidance of the eye registration system and 40 eyes from 29 patients without guidance from the eye registration system. The evaluation of astigmatism correction was performed by the Alpins method, measuring the amount and axis of astigmatism before and after the operations. RESULTS: The average of the correction index (the ratio of the surgically induced amount of astigmatism correction to the intended amount of astigmatism correction) for the eye registration group was calculated to be 0.94+/-0.30 and, for non-eye registration group, was 0.92+/-0.41, showing no statistical significant difference between the two groups (p=0.762). However, the comparison of the index of success (the ratio of the difference vector to the intended amount of astigmatism correction) favorably demonstrated the effectiveness of eye registration (0.23+/-0.34 for eye registration group, 0.47+/-0.54 for non-eye registration group, p=0.03). The absolute angle of error (AE), a measure of difference in angle between the ablated axis of astigmatism correction and the desired axis of astigmatism correction, was lower on average for the eye registration group than for the non-eye registration group (3.52+/-7.69 to 12.5+/-20.69 degrees, p=0.015). CONCLUSIONS: Eye registration-guided surface laser ablation is suggested to be beneficial for the reduction of errors in astigmatism correction.
Astigmatism ; Axis, Cervical Vertebra ; Eye ; Humans ; Laser Therapy ; Lasers, Excimer ; Retrospective Studies

PURPOSE: To evaluate the effects of wearing rigid gas permeable (RGP) contact lenses on the topographic changes in keratoconus. METHODS: Seventy-seven keratoconic eyes that wore multicurve RGP contact lenses and 30 keratoconic eyes that wore no contact lenses were retrospectively analyzed. The mean follow-ups were 22.6 and 20.5 months in the lens-wearing and control groups, respectively. Visual acuity, comfort, daily wearing time, and corneal staining were evaluated for both groups. The changes in topographic indices were compared between the lens-wearing and control groups. RESULTS: Multicurve RGP lens corrected logarithm of the minimum angle of resolution visual acuity of the lens-wearing group significantly improved from -0.016+/-0.065 to -0.032+/-0.10 at follow-up (p=0.05). In the lens-wearing group with advanced keratoconus, the Sim Kmax, Sim Kmin, apical power, astigmatic index, and anterior elevation significantly decreased from 57.68+/-4.26 diopter (D), 50.50+/-2.32 D, 62.79+/-5.11 D, 7.20+/-0.55 D and 67.36+/-16.30 microm to 55.51+/-4.28 D, 49.62+/-3.26 D, 60.31+/-5.41 D, 5.90+/-0.51 D and 60.61+/-16.09 microm, respectively (paired t-test, p<0.05). The irregularity index of 3 mm did not significantly change. Meanwhile, in the control group, the apical power and irregularity index increased from 55.56+/-7.25 D and 3.06+/-1.68 D to 57.11+/-7.75 D and 3.25+/-1.71 D, respectively (paired t-test, p=0.008, p=0.01). CONCLUSIONS: Properly fitted multicurve RGP contact lenses are not likely to contribute to the progression of keratoconus.
Adult ; Astigmatism/etiology/pathology/therapy ; *Contact Lenses ; Cornea/*pathology ; *Corneal Topography ; Disease Progression ; Female ; Follow-Up Studies ; Humans ; Keratoconus/complications/pathology/*therapy ; Male ; Prognosis ; Prosthesis Design ; Retrospective Studies ; Time Factors ; Young Adult

PURPOSE: To evaluate the clinical effect of photorefractive keratectomy (PRK) and laser assisted in situ keratomileusis (LASIK) on eyes with anisometropia due to residual astigmatism after cataract surgery. METHODS: We retrospectively reviewed the medical records of 11 eyes of 11 patients who had undergone cataract surgery from March 2002 to November 2005. PRK (2 eyes) and LASIK (9 eyes) was performed on 11 eyes with refractive myopic or mixed astigmatism over 1.5D after cataract surgery. RESULT: Before laser surgery, the mean astigmatism was 3.23+/-1.02D and the mean spherical equivalent (SE) was -2.27+/-1.43D. Six months after laser surgery, the mean SE was 0.66+/-0.58D and the mean astigmatism was 0.73+/-0.39D. The changes in mean manifest SE and astigmatism were statistically significant between paired preoperative and postoperative values (p<0.05). At 6 months after surgery, the mean uncorrected visual acuity and best corrected visual acuity significantly improved to 0.65+/-0.17 and 0.84+/-0.11, respectively. Three eyes (27.3%) developed mild haze and were treated without sequelae. There were no other complications. CONCLUSIONS: Excimer laser surgery appears to be a clinically useful procedure to correct residual astigmatism after cataract surgery.
Anisometropia ; Astigmatism ; Cataract ; Eye ; Humans ; Keratomileusis, Laser In Situ ; Laser Therapy ; Lasers, Excimer ; Medical Records ; Photorefractive Keratectomy ; Refractive Surgical Procedures ; Retrospective Studies ; Visual Acuity

In an effort to characterize, on the molecular scale, the Acanthamoeba initially isolated from the cornea of an amoebic keratitis patient associated with overnight-wear orthokeratology lens in Korea, we conducted mitochondrial DNA restriction fragment length polymorphism, 18S rDNA sequencing, and drug sensitivity analyses on the isolate (KA/PE1). The patient was treated with polyhexamethylene biguanide, chlorhexidine and oral itraconazole, which resulted in resolution of the patient's ocular inflammation. The majority of the molecular characteristics of the KA/PE1 were determined to be identical, or quite similar, to those of A. castellanii Ma strain, which had been isolated also from amoebic keratitis. The risk of Acanthamoeba keratitis as a potential complication of overnight orthokeratology is briefly discussed.
*Sequence Analysis, DNA ; RNA, Ribosomal, 18S/genetics ; Polymorphism, Restriction Fragment Length ; Parasitic Sensitivity Tests ; Myopia/therapy ; Itraconazole/administration & dosage ; Humans ; Female ; Disinfectants/administration & dosage ; DNA, Ribosomal/analysis ; DNA, Protozoan/analysis ; DNA, Mitochondrial/analysis ; Contact Lenses/*adverse effects ; Chlorhexidine/administration & dosage ; Biguanides/administration & dosage ; Astigmatism/therapy ; Antiprotozoal Agents/administration & dosage ; Animals ; Adolescent ; Acanthamoeba Keratitis/drug therapy/*parasitology ; Acanthamoeba/classification/*genetics/*isolation & purification

PURPOSE: To evaluate the effect of Nd:YAG laser posterior capsulotomy on refraction, anterior chamber depth (ACD), and intraocular pressure (IOP). METHODS: For forty-eight eyes of 38 patients who received Nd:YAG laser therapy, we measured visual acuity, refraction, ACD, and IOP before the capsulotomy and at 1 day, 7 days, 30 days, 90 days after. RESULTS: There were no significant difference in ACD or IOP after YAG laser capsulotomy (P>.05). But we found significant decrease in astigmatism 1day after laser treatment, especially In the large axial length group (> or =24 mm)(P<.05). This early change in astigmatism was recovered to similar to what it was before laser treatment. CONCLUSIONS: YAG laser treatment after treatment of cataract is a stable method without clinically significant effect on refraction, ACD, or IOP, except for transient astigmatic change.
Anterior Chamber ; Astigmatism ; Cataract ; Humans ; Intraocular Pressure ; Laser Therapy ; Lasers, Solid-State ; Posterior Capsulotomy* ; Visual Acuity

To determine if the involuntary contractions of eyelids may have any effects on the development of corneal astigmatism, we performed this prospective study which includes 19 patients with either essential blepharospasm or hemifacial spasm. In hemifacial spasm, the degree of corneal astigmatism was evaluated between two eyes. Then the topographic changes were checked using vector analysis technique before and after passively opening the eyelids. They were also measured before and at 1 and 6 months after the injection of Botulinum toxin. Resultantly, 20 eyes had the with-the-rule (group1) and 9 eyes against-the-rule (group2) astigmatism. In hemifacial spasm, significantly more astigmatism was found at spastic eyes. The corneal topographic changes after passively opening the eyelids showed 10 eyes with the astigmatic shift to the with-the-rule, while the remaining 19 to the againstthe- rule. At 1 month after injection of Botulinum toxin, group 1 showed reduced average corneal astigmatism, whereas group 2 showed increased astigmatism. The astigmatic change vector showed significantly more against-the-rule. In the contrary, 6 months after treatment, corneal astigmatism again increased in group 1 and decreased in group 2. So they took on the appearance of pretreatment astigmatic status eventually. Conclusively eyelids may play an important role in corneal curvature.
Aged ; Astigmatism/*drug therapy/physiopathology ; Blepharospasm/*drug therapy/physiopathology ; Botulinum Toxin Type A/administration & dosage/*therapeutic use ; Cornea/drug effects/physiopathology ; Corneal Diseases/*drug therapy/physiopathology ; Eyelids/drug effects/physiopathology ; Female ; Humans ; Injections ; Male ; Middle Aged ; Time Factors ; Treatment Outcome