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

PURPOSE: To evaluate the predictability of intraocular lens (IOL) power calculations using the IOLMaster and four different IOL power calculation formulas (Haigis, Hoffer Q, SRK II, and SRK/T) for cataract surgery in eyes with a short axial length (AL). METHODS: The present study was a retrospective comparative analysis which included 25 eyes with an AL shorter than 22.0 mm that underwent uneventful phacoemulsification with IOL implantation from July 2007 to December 2008 at Seoul National University Boramae Hospital. Preoperative AL and keratometric power were measured by the IOLMaster, and power of the implanted IOL was determined using Haigis, Hoffer Q, SRK II, and SRK/T formulas. Postoperative refractive errors two months after surgery were measured using automatic refracto-keratometry (Nidek) and were compared with the predicted postoperative power. The mean absolute error (MAE) was defined as the average of the absolute value of the difference between actual and predicted spherical equivalences of postoperative refractive error. RESULTS: The MAE was smallest with the Haigis formula (0.37 +/- 0.26 diopter [D]), followed by those of SRK/T (0.53 +/- 0.25 D), SRK II (0.56 +/- 0.20 D), and Hoffer Q (0.62 +/- 0.16 D) in 25 eyes with an AL shorter than 22.0 mm. The proportion with an absolute error (AE) of less than 1 D was greatest in the Haigis formula (96%), followed by those in the SRK II (88%), SRK-T (84%), and Hoffer Q (80%). CONCLUSIONS: The MAE was less than 0.7 D and the proportion of AE less than 1 D was more than 80% in all formulas. The IOL power calculation using the Haigis formula showed the best results for postoperative power prediction in short eyes.
Aged ; Aged, 80 and over ; Female ; Humans ; Lens Implantation, Intraocular ; *Lenses, Intraocular ; Male ; Middle Aged ; *Optics and Photonics ; Phacoemulsification ; Postoperative Period ; Refractive Errors/diagnosis/physiopathology ; Retrospective Studies

PURPOSE: We analyzed the effect of the changes of the optic disc area (ODA) caused by the axial length and the refractive error, and the consequent changes of the distance from the optic disc margin to the circular scan (OD-CS) of Optical coherence tomography (OCT) on the measurement of the retinal nerve fiber layer thickness(RNFLT) were examined. METHODS: One hundred two eyes of 51 children (age range 4 to 15 years) were measured using OCT including the RNFLT. For the ODA and the OD-CS, the relative area formed by the ODA and the circular scan was obtained. In addition, the correlation of the refractive error and the axial length to the optic disc factors was assessed. RESULTS: As hyperopia progresses to myopia, the axial length became longer, the ODA became smaller (r=-0.442, p=0.000) and the OD-CS showed a tendency to increase (r=0.471, p=0.000). As the OD-CS became longer, the measured average RNFLT decreased significantly (r=-0.248, p=0.012), and the ODA and the OD-CS showed a significant correlation to the RNFL thickness that was measured in the nasal and inferior areas, the S2, N2 and N3 areas and the I1 area. CONCLUSIONS: As ODA becomes smaller and the OD-CS becomes longer, the RNFLT measured in the nasal and inferior areas, the S2, N2, N3, I1 area has a tendency to be thinner. Hence, consideration of the disc area is required when interpreting the RNFLT of these eyes.
Adolescent ; Aging/physiology ; Child ; Child, Preschool ; Female ; Glaucoma/diagnosis ; Humans ; Male ; Nerve Fibers/*pathology ; Optic Disk/*pathology ; Optic Nerve Diseases/*physiopathology ; Refraction, Ocular ; Refractive Errors/*physiopathology ; Retinal Ganglion Cells/*pathology ; Tomography, Optical Coherence ; Visual Acuity

PURPOSE: To evaluate the refractive predictability of a partial coherence interferometry (PCI) biometry device (IOL Master(R)) for cataract surgery and to investigate factors that may affect it. METHODS: Retrospective review of 209 eyes from 151 patients that had undergone preoperative PCI biometry and an uneventful phacoemulsification cataract surgery with posterior chamber intraocular lens (IOL) implantation was conducted. Prediction error defined as the intended refraction minus the postoperative refraction in spherical equivalent (SE) and the absolute error were analyzed according to IOL calculation formulas, patient characteristics, preoperative visual acuity (VA) and refraction, posterior subcapsular cataract (PSC), signal-to-noise ratio (SNR), and axial length (AL). RESULTS: The overall refractive predictability of the PCI device was good. Generally, the SRK/T formula performed better than the SRK-II formula. Refractive predictability was slightly worse in eyes with > or =+2.0 diopters (D) of preoperative SE (with both SRK-II and SRK/T) and in eyes with an AL< or =23.0 mm (only with SRK-II. No other factors significantly affected the refractive predictability of the PCI, although poor VA, dense PSC, and poor SNR were closely interrelated. CONCLUSIONS: The SRK/T formula performed significantly better than the SRK-II formula. Eyes with an AL< or =23.0 mm were associated with significantly greater hyperopic shifts in postoperative refraction with the SRK-II formula, but not with the SRK/T formula. A preoperative SE> or =+2.0D was related to a significantly greater hyperopic shift in postoperative refraction. With proper verification of measured data and a suitable IOL calculation formula, good refractive predictability is expected from PCI biometry regardless of patient characteristics, preoperative VA, SNR, PSC, and AL.
Aged ; Aged, 80 and over ; Female ; Humans ; Interferometry/*methods ; Lens Implantation, Intraocular ; *Lenses, Intraocular ; Light ; Male ; Phacoemulsification/*methods ; *Refraction, Ocular ; Refractive Errors/*diagnosis/physiopathology ; Reproducibility of Results ; Retrospective Studies ; Visual Acuity

PURPOSE: To maximize effective use of mydriatic drugs through comparing the pupillary dilation effects between 1% tropicamide and 2.5% phenylephrine. METHODS: Fifty people requiring pupillary dilation were divided into 3 groups. Group 1 was treated with one drop of 1% tropicamide in the right eye and one drop of 2.5% phenylephrine in the left eye. Group 2 was treated twice during a 5-minute interval with 1% tropicamide in the right eye. Group 3 was treated twice during a 5-minute interval with 2.5% phenylephrine in the right eye. Groups 2 and 3 were treated with 2.5% phenylephrine and 1% tropicamide in the left eye, administered during a 5-minute interval. The pupillary size was measured in all groups for 40 minutes following eye drops administration. RESULTS: The mean patient age was 15.7 years. Group 1 included 10 patients, and groups 2 and 3 included 20 patients each. Eight patients in group 1 and 16 patients in group 2 developed a larger right pupil. Fourteen patients in group 3 developed a larger left pupil. CONCLUSIONS: Our study showed that 1% tropicamide, with its parasympathetic antagonistic mechanism of action, was more effective at inducing pupillary dilation than 2.5% phenylephrine, and the combination of 1% tropicamide and 2.5% phenylephrine was more effective than multiple drops of single eye drops.
Adolescent ; Adult ; Child ; Child, Preschool ; Dose-Response Relationship, Drug ; Drug Administration Schedule ; Female ; Follow-Up Studies ; Humans ; Male ; Muscarinic Antagonists/*administration & dosage ; Mydriatics/*administration & dosage ; Ophthalmic Solutions ; Phenylephrine/*administration & dosage ; Pupil/*drug effects ; Refractive Errors/diagnosis/physiopathology ; Retrospective Studies ; Tropicamide/*administration & dosage ; Young Adult