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Objetivo: Determinar las aberraciones corneales en pacientes con indicación de cirugía refractiva con láser de excímeros. Métodos: Se realizó un estudio retrospectivo, transversal, descriptivo, con 161 ojos de 81 pacientes adultos, de ambos sexos con indicación de cirugía con láser de excímeros para la corrección de su defecto refractivo. Se definieron como variables edad, sexo, desenfoque, astigmatismo, coma, trefoil y aberración esférica, las que se determinaron por el estudio topográfico de rutina con el topógrafo KeratronTM Scout, Optikon. Resultados: Se obtuvieron los siguientes valores promedios: desenfoque -4,17 ± 0,29 D (-16,15 a 8,5 D) y absoluto 4,94 ± 0,199 (10 a 16,5 D), astigmatismo -1,56 ± 0,09 D (-9,44 a -0,09 D), coma 0,25 ± 0,016 (0,01 a 1,5 D), trefoil 0,204 ± 0,016 (0,01 a 1,18 D) y aberración esférica 0,316 ± 0,018 D (0,0 a 1,27D). En el 75 % de los casos los valores absolutos de desenfoque fueron inferiores a 6,56, de astigmatismo inferior a 0,33 D, de coma menor que 0,33, trefoil inferior a 0,25 y aberraciones esféricas menores que 0,32 D. Conclusiones: Los valores promedio de las aberraciones corneales desenfoque, astigmatismo, coma, trefoil y aberración esférica se encuentran en el rango de los valores reportados en la literatura científica y la distribución de los valores de las aberraciones corneales presentan desplazamiento de la mayoría de los casos hacia los valores más bajo del rango de determinación.
Objective: To determine corneal aberrations in patients indicated for excimer laser refractive surgery. Methods: A retrospective, cross-sectional and descriptive study was carried out with 161 eyes of 81 adult patients of both sexes with indication of excimer laser surgery for the correction of their refractive defect. Age, sex, defocus, astigmatism, coma, trefoil and spherical aberration were defined as variables, determined by routine topographic study with the KeratronTM Scout topographer, Optikon. Results: The following average values were obtained: defocus of -4.17 ± 0.29 D (-16.15 to 8.5 D) and absolute of 4.94 ± 0.199 (10 to 16.5 D), astigmatism of -1.56 ± 0.09 D (-9.44 to -0.09 D), coma of 0.25 ± 0.016 (0.01 to 1.5 D), trefoil of 0.204 ± 0.016 (0.01 to 1.18 D) and spherical aberration of 0.316 ± 0.018 D (0.0 to 1.27D). In 75 % of the cases, the absolute values for defocus were lower than 6.56; for astigmatism, lower than 0.33 D; for coma, lower than 0.33; for trefoil, lower than 0.25; and for spherical aberrations, lower than 0.32 D. Conclusions: The average values of corneal aberrations for defocus, astigmatism, coma, trefoil and spherical aberration are in the range of values reported in the scientific literature, while the distribution of corneal aberrations values present displacement of most of the cases towards the lower values of the determination range.
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Purpose: To assess the morphological changes in the anterior segment following laser peripheral iridotomy (LPI) in primary angle?closure disease (PACD) using Sirius Scheimpflug?Placido disk corneal topographer. Methods: This was a prospective observational study. A total of 52 eyes of 27 patients with PACD who underwent LPI were analyzed for iridocorneal angle (ICA), anterior chamber depth (ACD), anterior chamber volume (ACV), horizontal visible iris diameter (HVID), corneal volume (CV), central corneal thickness (CCT), and horizontal anterior chamber diameter (HACD) 1 week following LPI, using Sirius Scheimpflug?Placido disk corneal topographer. Data analysis was done using Statistical Package for the Social Sciences (SPSS) software version 19.0, and paired t?test was used to assess the statistical significance. Results: Laser peripheral iridotomy was performed in 43 eyes with primary angle?closure suspect (PACS), six eyes with primary angle closure (PAC), and three eyes with primary angle?closure glaucoma (PACG). The analysis of the data showed statistically significant changes in anterior segment parameters of ICA, ACD, and ACV. Post?laser increase in ICA from 34.13° ± 2.64° to 34.75° ± 2.84° (P < 0.041), mean ACD increase from 2.21 ± 0.25 to 2.35 ± 0.27 mm (P = 0.01), and mean ACV increase from 98.19 ± 12.13 to 104.15 ± 11.16 mm3 (P = 0.001) were noted. Conclusion: Significantly quantifiable short?term changes in the anterior chamber parameters of ICA, ACD, and AC volume were seen after LPI in patients with PACD on Sirius Scheimpflug?Placido disc corneal topographer.
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@#AIM: To observe the location characteristics of the earliest tear film breakup in elderly patients with dry eyes.METHODS: Cross-sectional study. The 154 elderly patients with dry eyes in our hospital from July 2019 to December 2019 were included, with 143 right eyes, 124 left eyes, and 71 patients were males, 83 patients were females, aged 68-90(mean: 73.40±4.13)years old. The location of the earliest tear film breakup was investigated by using corneal topographer. The cornea was separated to four sectors to record the earliest tear film breakup location by anticlockwise order. The sector corresponding to the right eye was nasal superior, temporal superior, temporal inferior and nasal inferior respectively. And it corresponding to the left eye was temporal superior, nasal superior, nasal inferior and temporal inferior respectively. Then the sector which was the earliest tear film breakup location was recorded. At the same time, the distance which was from the earliest tear film breakup location to the centre of cornea was recorded too.RESULTS: The highest constituent ratio of area of right eye was nasal inferior(28.7%), then was temporal inferior(27.3%), nasal superior(20.3%), temporal superior(11.2%), and the constituent ratio of earliest tear film breakup occurred in 2-3 areas at the same time was 12.6%. The constituent ratio of the earliest tear film breakup area of left eye also was nasal inferior(31.5%), then was temporal inferior(25.0%), nasal superior(23.4%), temporal superior(11.3%), the constituent ratio of earliest tear film breakup occurred in 2-3 areas at the same time was 8.9%. There was no difference in the constituent ratio of tear film breakup area between two eyes(χ2=1.443, <i>P</i>=0.837). The distance from the earliest tear film breakup area of the nasal inferior quadrant to the centre of cornea was mostly the zone from 1.5-2mm and 2-2.5mm in both eyes.CONCLUSION: There is a certain regularity in the characteristics of tear film breakup area in elderly patients with dry eyes, and the earliest tear film breakup area of both eyes is mainly occurred in nasal inferior, and there is no significant difference between two eyes.
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@#Introduction: Precise pupillometry is crucial to determine ablation optical zone (OZ) size selection in LASIK. Significant difference in the selection induces unwanted postoperative night visual disturbance. Placido-disc topographer and Hartmann-Shack aberrometer are commonly used in LASIK preoperative assessment. However, little is known on the precision and agreement of these devices in pupillometry. Hence, this study aimed to evaluate the precision (repeatability and reproducibility) and inter-device agreement of a Placido-disc topographer and Hartmann-Shack aberrometer in measuring mesopic pupil size in pre-LASIK patients. Methods: Mesopic pupillometry on 38 pre-LASIK patients were performed using both devices by two masked operators, on two separate sessions. Intra-session repeatability, inter-operator reproducibility and inter-device agreement were analysed. A disagreement value of ±0.5 mm and 95% limits of agreement (LoA) were determined. Results: Hartmann-Shack aberrometer demonstrated higher repeatability and reproducibility than Placido-disc topographer in mesopic pupillometry. Ninety-seven percent and all of Hartmann-Shack wavefront aberrometer pupillometry were within ±0.5 mm in repeated sessions and between the operators, respectively. The mesopic pupil size obtained from Placido-disc topographer was significantly larger than Hartmann-Shack aberrometer results (P = 0.02). The agreement between devices was low (LoA > ±1 mm) and only 53% of Placido-disc topographer pupillometry were within ±0.5 mm of Hartmann-Shack aberrometer pupillometry. Conclusion: Hartmann-Shack aberrometer has higher precision within sessions and between operators, and it provides smaller mesopic pupillometry than Placido-disc topographer. Precise mesopic pupillometry could assist refractive surgeons in choosing a correct ablation OZ size during LASIK surgery to improve postoperative outcome.
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@#AIM: To evaluate the difference and consistency of pupillary offset measured by the Pentacam anterior segment analyzer and Keratron Scout corneal topographer.<p>METHODS: Three hundred and eleven patients(604 eyes)who underwent excimer laser in situ keratomileusis from November 2017 to February 2018 were randomly selected. Before surgery, the pupillary offset values were measured by Pentacam and Keratron, and the differences and consistency of the values between the two instruments were compared.<p>RESULTS: The pupillary offset values of the right eyes, left eyes, and both eyes between Pentacam and Keratron were statistically different(<i>P</i><0.05). There were no significant statistical differences in the offset orientations of right eyes, left eyes and both eyes between the two instruments(<i>P</i>>0.05). The 95% consistent line(<i>LoA</i>)of offset value and offset orientation in the right eyes, left eyes and both eyes between the two instruments were -0.11-0.19mm and -157.01°-135.35°, -0.12-0.18mm and -150.16°-158.22°, -0.11-0.19mm and -154.30°-147.10°, respectively. <p>CONCLUSION: The pupillary offset measured by the Pentacam was smaller than that measured by the Keratron, but the difference was within the clinically acceptable range. The accurate pupillary offset can be obtained, and be the mutual reference, correction and supplement in the both instruments.
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@#AIM: To investigate the repeatability and agreement of Pentacam Front Section Analyzer and Keratron Scout Corneal Topographer in measuring Kappa angle.<p>METHODS: Totally 69 patients were randomly selected from Ophthalmology Department of Leshan People's Hospital. Three readings were taken by the same examiner. Results were recorded in(<i>X</i>, <i>Y</i>)coordinates format and assessed by intraclass correlation coefficient(ICC), Cronbach's Alpha Coefficient, <i>t-</i>test, Pearson correlation analysis and bland-altman analysis.<p>RESULTS: Both instruments showed excellent repeatability in Kappa angle assessment. The results significantly correlated(<i>X</i> value: <i>r</i>=0.90,<i> P</i><0.01; <i>Y</i> value: <i>r</i>=0.91, <i>P</i><0.01), however, no significant difference were found between the two instruments. The widest 95% LoA was -0.11-0.14mm for <i>X</i> coordinate and -0.10-0.11mm for <i>Y</i>.<p>CONCLUSION: Pentacam and Keratron Scout showed excellent repeatability and agreement in Kappa angle assessment. The two instruments could aid and verify each other.
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PURPOSE: To determine the power vector and aberrations before and after surgery for pterygium using a corneal topographer and a wavefront aberrometer. METHODS: The study group consisted of 34 eyes of 31 patients with pterygium, and were divided into two groups by pterygium size ( or = 3 mm, group II). Power vector and wavefront aberrations were evaluated using a corneal topographer (Oculus inc., Germany) and a wavefront aberrometer (LADARWAVE(R), Hartmann shack aberrometer, Alcon inc., US) at pre- and postoperative 1 week, 1 month, and 3 months. RESULTS: The preoperative blurring strength (B) and high order aberrations significantly decreased at postoperative 3 months in all groups (P or = 3 mm). To reduce aberrations and astigmatism effectively, we suggested surgical intervention in eyes with pterygia sized < 3.0 mm.