PURPOSE: To evaluate the effects of the amount of myopic correction on long-term changes in higher-order wavefront aberrations (HOAs) in advanced surface ablation-photorefractive keratectomy (ASA-PRK). METHODS: The 193 eyes of 101 patients who underwent ASA-PRK were divided into two groups according to the amount of myopic correction by the median value (Group 1 < or = -4.37D, 97 eyes, mean -3.26 +/- 0.77D; Group 2 > -4.37D, 96 eyes, mean -5.77 +/- 1.00D). Wavefront aberrometry was performed to measure total HOA, coma, trefoil, and spherical aberration preoperatively and at 1, 3, 6, 12, and 24 months after ASA-PRK. Statistical analysis was performed to compare changes in all HOAs between the two groups. RESULTS: Each magnitude of total HOA, coma, and spherical aberration except trefoil significantly increased at 1, 3, 6, 12, and 24 months postoperatively in each group (p<0.05), and the increases were statistically significantly higher in group 2 compared to those of group 1 (p<0.05). The amount of changes in all HOAs except trefoil revealed that statistically significantly higher increases in group 2 compared to those of group 1 were determined only in the short-term period (up to 1 month, p<0.05), but not in the medium-term (1 to 6 months) or long-term periods (6 to 24 months). CONCLUSIONS: Postoperative total HOA, coma, and spherical aberration significantly increased in both groups, and these increases in surgery-induced HOAs were significantly higher in group 2 (> -4.37D). Increases in ASA-PRK-induced HOAs primarily originated from short-term changes in the postoperative one-month period and did not return to the preoperative level during the postoperative two-year period.
Aberrometry ; Aniline Compounds ; Coma ; Eye ; Humans ; Lotus

PURPOSE: To analyze the positional relationships of various centers in patients undergoing femtosecond laser-assisted cataract surgery (FLACS). METHODS: The locations of the pupil center (PC), limbal center (LC) and lens center were analyzed in each patient using optical coherence tomography during FLACS in 35 eyes of 35 patients. Using the preoperative corneal aberrometry device, angle kappa and the location of the visual axis (VA) were calculated. After acquiring the relative horizontal and vertical coordinates of each center, the distance and location among each center were compared. The relative location and distance of each center were statistically evaluated. RESULTS: The distance from the PC to the lens center was 0.147 ± 0.103 mm, that from the LC to the lens center was 0.205 ± 0.104 mm, and that from the VA to the lens center was 0.296 ± 0.198 mm. The distance from the PC to the VA was 0.283 ± 0.161 mm, that from the LC to the VA was 0.362 ± 0.153 mm, and that from the lens center to the VA was 0.296 ± 0.198 mm. Among the various centers, the PC was the closest to the lens center, whereas the LC and VA were the farthest. Based on the location of the lens center, the PC, LC, and VA exhibited differences in the X and Y coordinate positions (vertical p = 0.004, horizontal p < 0.001). Among them, the LC was significantly inferior and temporal compared to the PC (vertical p = 0.026, horizontal p = 0.023). Based on the location of the VA, the respective locations of the PC, LC and lens center in two dimensions did not significantly differ (vertical p = 0.310, horizontal p = 0.926). CONCLUSIONS: This study demonstrated the positional and locational relationships between the centers regarding FLACS. The locations of the PC, LC, and VA were different from the lens center with the PC being the closest. Surgeons should be aware of these positional relationships, especially in FLACS.
Aberrometry ; Cataract ; Humans ; Pupil ; Surgeons ; Tomography, Optical Coherence

PURPOSE: In this study evaluated clinical outcomes and higher-order aberrations in patients with implanted Tecnis ZCT toric intraocular lens (IOL) (Abbott Medical Optics Inc., Santa Ana, CA, USA) and the Zeiss AT TORBI toric IOL (Carl Zeiss Meditec AG, Jena, Germany) in eyes with low to moderate corneal astigmatism. METHODS: We conducted a retrospective study of 32 consecutive eyes of 26 patients with a visually significant cataract and moderate corneal astigmatism (higher than 1.25 diopter [D] and lower than 4.5 D) undergoing cataract surgery with implantation of the aspheric Tecnis ZCT toric IOL (Abbott Medical Optics Inc.) and the Zeiss AT TORBI toric IOL (Carl Zeiss Meditec AG). Phacoemulsification was performed by the same experienced surgeon using 2.2 mm temporal incision. Visual, refractive and aberrometric changes were evaluated during a 3-month follow-up. Power vector analysis of Cartesian astigmatism (J0) and oblique astigmatism (J45) was performed. RESULTS: At the 3-month follow-up, corrected distance visual acuity (CDVA) and residual astigmatism showed no statistically significant differences between groups (p = 0.203 and p = 0.364, respectively). Pre- and postoperative J0 were 0.71 +/- 0.84 and 0.05 +/- 0.39 in the Tecnis Toric group and, 0.88 +/- 1.27 and -0.02 +/- 0.16 in the AT TORBI group, respectively, which showed statistically significant differences (p = 0.029 and p = 0.032, respectively). Pre- and post-operative differences of J0 and J45 were not statistically significant (p = 0.234 and p = 0.603, respectively). No eye had IOL rotation > or =10degrees. Ocular aberrometry values were statistically significantly differenct between the groups, except for spherical aberration, which was higher in the AT TORBI group (p = 0.0047). CONCLUSIONS: Both IOLs showed good postoperative uncorrected distance visual acuity, CDVA and refractive results in this study. Rotational stability was excellent for both IOLs until the 3-month follow-up.
Aberrometry ; Astigmatism ; Cataract ; Follow-Up Studies ; Humans ; Lenses, Intraocular* ; Phacoemulsification ; Retrospective Studies ; Visual Acuity

BACKGROUNDThe evaluation of retinal image quality in cataract eyes has gained importance and the clinical modulation transfer functions (MTF) can obtained by aberrometer and double pass (DP) system. This study aimed to compare MTF derived from a ray tracing aberrometer and a DP system in early cataractous and normal eyes.

METHODSThere were 128 subjects with 61 control eyes and 67 eyes with early cataract defined according to the Lens Opacities Classification System III. A laser ray-tracing wavefront aberrometer (iTrace) and a double pass (DP) system (OQAS) assessed ocular MTF for 6.0 mm pupil diameters following dilation. Areas under the MTF (AUMTF) and their correlations were analyzed. Stepwise multiple regression analysis assessed factors affecting the differences between iTrace- and OQAS-derived AUMTF for the early cataract group.

RESULTSFor both early cataract and control groups, iTrace-derived MTFs were higher than OQAS-derived MTFs across a range of spatial frequencies (P < 0.01). No significant difference between the two groups occurred for iTrace-derived AUMTF, but the early cataract group had significantly smaller OQAS-derived AUMTF than did the control group (P < 0.01). AUMTF determined from both the techniques demonstrated significant correlations with nuclear opacities, higher-order aberrations (HOAs), visual acuity, and contrast sensitivity functions, while the OQAS-derived AUMTF also demonstrated significant correlations with age and cortical opacity grade. The factors significantly affecting the difference between iTrace and OQAS AUMTF were root-mean-squared HOAs (standardized beta coefficient = -0.63, P < 0.01) and age (standardized beta coefficient = 0.26, P < 0.01).

CONCLUSIONSMTFs determined from a iTrace and a DP system (OQAS) differ significantly in early cataractous and normal subjects. Correlations with visual performance were higher for the DP system. OQAS-derived MTF may be useful as an indicator of visual performance in early cataract eyes.

Aberrometry ; methods ; Adult ; Aged ; Cataract ; physiopathology ; Female ; Humans ; Male ; Middle Aged ; Visual Acuity ; physiology

BACKGROUNDAmblyopia is a common ophthalmological condition and the wavefront aberrometer is a relatively new diagnostic tool used globally to measure optical characteristics of human eyes as well as to study refractive errors in amblyopic eyes. We studied the wavefront aberration of the amblyopic children's eyes and analyzed the mechanism of the wavefront aberration in the formation of the amblyopia, try to investigate the new evidence of the treatment of the amblyopia, especially in the refractory amblyopia.

METHODSThe WaveScan Wavefront System (VISX, USA) aberrometer was used to investigate four groups of children under dark accommodation and cilliary muscle paralysis. There were 45 cases in the metropic group, 87 in the amblyopic group, 92 in the corrected-amblyopic group and 38 in the refractory amblyopic group. One-way analysis of variance (ANOVA), t-test and multivariate linear regression were used to analyze all the data.

RESULTSThird order to 6th order aberrations showed a decreasing trend whereas in the higher order aberrations the main ones were 3rd order coma (Z(3)(-1)-Z(3)(1)), trefoil (Z(3)(-3)-Z(3)(3)) and 4th order aberration (Z(4)(0)); and 3rd order coma represented the highest percentage of all three main aberrations. Within 3rd order coma, vertical coma (Z(3)(-1)) accounted for a greater percentage than horizontal coma (Z(3)(1)). Significant differences of vertical coma were found among all clinical groups of children: vertical coma in the amblyopic group (0.17 +/- 0.15) was significantly higher than in the metropic group (0.11 +/- 0.13, P < 0.05). In addition, the vertical coma in the refractory amblyopic group (0.19 +/- 0.15) was higher compared with the metropic group (P < 0.05), the 5th order aberration (0.11 +/- 0.08) was also significantly higher than in the metropic group (0.07 +/- 0.04, P < 0.05). No significant difference was found in vertical coma and 5th order aberration between the corrected-amblyopic group (0.13 +/- 0.11) and metropic group (0.07 +/- 0.04) (P > 0.05).

CONCLUSIONSAlthough lower order aberrations such as defocus (myopia and hyperopia) and astigmatism are major factors determining the quality of the retinal image, higher order aberrations also need to be considered in amblyopic eyes as their effects are significant.

Aberrometry ; Amblyopia ; pathology ; physiopathology ; Child ; Child, Preschool ; Female ; Humans ; Male ; Refraction, Ocular ; physiology ; Refractive Errors ; diagnosis ; pathology

Higher order aberrations (HOAs) were measured in 54 anisometropic amblyopic children using the ZY-WAVE II aberrometer. The results were compared in normal fellow and amblyoic eyes which were determined by the corrected visual acuity. Between the normal eyes and anisometropic amblyopic eyes, no statistically significant difference were found in mean root square of total HOAs, total coma (TC), total spherical aberration (TSA), and the 5th root mean square (RMS5). There was no correlation among best corrected visual acuity (BCVA), HOAs, TC, TSA, and RMS5. There was some positively correlation between the degree of anisometropia and TC. HOAs increase with the increasing of the degree of anisometropic amblyopia. Lower order aberrations are the main refractive factors leading to amblyopia, and HOAs is related to anisometropia amblyopia. The study helps us understand the mechanism of amblyopia and make the further study.
Aberrometry ; Adolescent ; Amblyopia ; diagnosis ; physiopathology ; Child ; Corneal Wavefront Aberration ; physiopathology ; Female ; Humans ; Male ; Refraction, Ocular ; physiology ; Visual Acuity ; physiology

PURPOSE: To compare the astigmatic power of toric intraocular lenses (IOLs) obtained from the AcrySof, TECNIS, and iTrace toric calculator in patients with preoperative with-the-rule (WTR) or against-the-rule (ATR) corneal astigmatism. MATERIALS AND METHODS: Fifty eyes with cataract and corneal astigmatism greater than 0.75 diopters were enrolled in each group (WTR and ATR). Keratometric values were measured using autokeratometry, an IOLMaster, and an iTrace, which incorporated corneal topography and ray-tracing aberrometry. Based on measured keratometric values, the astigmatic power of each toric IOL was calculated using three toric calculators. RESULTS: Bland-Altman plots showed good agreement between six pairwise corneal astigmatism values in both groups. The TECNIS calculator tended to suggest a higher astigmatic power of the toric IOL than the AcrySof calculator. With the higher astigmatism and keratometric values from the IOLMaster, in both groups, calculations from the AcrySof and TECNIS calculators resulted in higher calculated astigmatic powers than those from same calculators with autokeratometry-measured values, demonstrating good agreement. With the higher calculated astigmatic power values, the values from the iTrace toric calculator using keratometric values obtained from iTrace ray tracing wavefront aberrometry or iTrace simulated keratometry showed fair to moderate agreement with those from the other calculator-keratometry pairs in both groups. CONCLUSION: To achieve the best refractive outcome after toric IOL implantation, understanding the differences in keratometric values between instruments and in calculated astigmatic power among toric calculator programs is necessary. Moreover, systemic analysis of each toric calculator in conjunction with postoperative data is required.
Aberrometry ; Aged ; Aged, 80 and over ; Astigmatism/physiopathology/surgery ; *Cataract ; Cornea/surgery ; Corneal Topography ; Eye ; Female ; Humans ; *Lens Implantation, Intraocular ; *Lenses, Intraocular ; Male ; Middle Aged ; Phacoemulsification/*methods ; Postoperative Period ; Refraction, Ocular/*physiology ; Visual Acuity/physiology

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