![]() When comparing the two groups, a significant difference in coma HOA at the 12-month follow-up was detected (p = 0.043). In both groups, all corneal HOAs were significantly reduced during amblyopia treatment. There was a statistically significant difference in success rate between the higher and lower astigmatism groups. 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. Correlation analysis was performed to assess the association between HOA and astigmatism. Corneal HOA was measured using a KR-1W aberrometer at the initial visit and at 3-, 6-, and 12-month follow-ups. Patients were divided into two groups based on the degree of astigmatism. In this retrospective study, a total of 72 eyes from 72 patients ranging in age from 38 to 161 months were included. To investigate the changes in corneal higher-order aberration (HOA) during amblyopia treatment and the correlation between HOA and astigmatism in hyperopic amblyopia children. Higher Order Aberration and Astigmatism in Children with Hyperopic Amblyopia. Thus, the proposed novel system is promising for quantitative and reliable in situ observations, particularly in environmental TEM applications. All of these aberration corrections, as well as auto focus tracking, were performed at a video frame rate of 1/30 s. ![]() Here, the measurement precision for 2-fold astigmatism was found to be Â☐.4 nm and Â☒°. In contrast, 2-fold astigmatism could be measured and corrected in real time from the reconstructed wave field. In this study, these aberration coefficients were estimated from an apparent 2-fold astigmatism induced under tilted-illumination conditions. Using the newly developed system, the coma aberration and 3-fold astigmatism were corrected using the aberration coefficients obtained experimentally before the processing was carried out. The aberration correction function was developed by modifying the image-processing software previously designed for auto focus tracking, as described in the first article of this series. In this study, a function for the correction of coma aberration, 3-fold astigmatism and real-time correction of 2-fold astigmatism was newly incorporated into a recently developed real-time wave field reconstruction TEM system. Tamura, Takahiro Kimura, Yoshihide Takai, Yoshizo Disregarding RA and treating TCA along with the corneal HOAs is recommended instead.ĭevelopment of a real-time wave field reconstruction TEM system (II): correction of coma aberration and 3-fold astigmatism, and real-time correction of 2-fold astigmatism. If topography-guided ablation is programmed to correct the corneal HOAs and RA, the astigmatic component caused by the coma-like corneal HOAs will be treated twice and will result in induced astigmatism. Coma-like corneal aberrations seem to contribute a considerable astigmatic component to RA in eyes with coma-like-aberrations dominant corneal optics. After simulated correction of anterior corneal HOAs along with TCA and RA (strategies 1 and 2), only a small amount of anterior corneal astigmatism (ACA) and no TCA remained after strategy 1, while considerable amount of ACA and TCA remained after strategy 2. Vertical coma influenced RA by canceling the effect of the with-the-rule astigmatism and increasing the effect of the against-the-rule astigmatism. Axis of discrepant astigmatism (RA minus TCA minus LA) correlated strongly with axis of coma. Correction of total corneal astigmatism (TCA) and RA was intended as well with strategies 1 and 2, respectively. Two different strategies were used for simulated treatments aiming to regularize irregular corneal optics: With both strategies correction of anterior corneal surface irregularities (corneal HOAs) were intended. Vector analysis was used to evaluate the contribution of coma-like corneal HOAs to RA. Eleven eyes with coma-like-aberrations-dominant corneal optics and with low lenticular astigmatism (LA) were selected for astigmatism analysis and for treatment simulations with topography-guided custom ablation. The aim of the study is to raise the awareness of the influence of coma-like higher-order aberrations (HOAs) on power and orientation of refractive astigmatism (RA) and to explore how to account for that influence in the planning of topography-guided refractive surgery in eyes with coma-like-aberrations-dominant corneal optics. Zhou, Wen Stojanovic, Aleksandar Utheim, Tor Paaske Assessment of refractive astigmatism and simulated therapeutic refractive surgery strategies in coma-like-aberrations-dominant corneal optics.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |