Purpose: To analyze the influence of specific combinations of corneal high order aberrations on the optical image quality of the cornea before and after photorefractive keratectomy (PRK) for low to high myopia and myopic astigmatism.
Methods: Corneal topography was obtained for 80 eyes that underwent PRK using a scanning-spot excimer laser. The eyes were subdivided into three groups according to the preoperative refraction. The topographical data were imported into a custom software program that combined the Zernike high order terms having the same sign and angular frequency up to seventh order for 4-mm and 6-mm pupils, ie, coma and spherical aberrations, and midperipheral and peripheral high order aberrations.
Results: Photorefractive keratectomy induced a significant amount of the root-mean-square (RMS) values of the combinations of midperipheral and peripheral high order aberrations over the smaller pupil size for deeper myopic ablations (P<.05). Over the larger pupil, spherical myopic ablations showed a significant increase (P<.05) of the RMS values of coma and spherical aberrations. In the astigmatism group, the combination of terms having higher angular frequency increased significantly (P<.05) after surgery both over 4-mm and 6-mm pupils.
Conclusions: After surface ablation, ablation depth and profile significantly influence the distribution and contribution of determined combinations of high order aberrations to the overall high order corneal wavefront aberration. Terms having high angular frequency were increased following large myopic correction and wide treatment zone. Quality of the whole corneal optics will be enhanced by designing future ablation profiles to compensate for peripheral high order optical aberrations.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.3928/1081-597X-20060901-06 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Inverse dose protraction effects of high-LET radiation: evidence and significance.
Mutat Res Rev Mutat Res
January 2025
Radiation Epidemiology Branch, National Cancer Institute, MD 20892-9778, USA; Faculty of Health, Science and Technology, Oxford Brookes University, Headington Campus, OX3 0BP, UK.
Biological effects of ionizing radiation vary with radiation quality, which is often expressed as the amount of energy deposited per unit length, i.e., linear energy transfer (LET).
View Article and Find Full Text PDFStructure of E6AP in complex with HPV16-E6 and p53 reveals a novel ordered domain important for E3 ligase activation.
Structure
January 2025
Department of Chemistry, Purdue University, West Lafayette, IN 47907, USA. Electronic address:
High-risk human papillomavirus E6 oncoprotein is a model system for the recognition and degradation of cellular p53 tumor suppressor protein. There remains a gap in the understanding of the ubiquitin transfer reaction, including placement of the E6AP catalytic HECT domain of the ligase concerning the p53 substrate and how E6 itself is protected from ubiquitination. We determined the cryoelectron microscopy (cryo-EM) structure of the E6AP/E6/p53 complex, related the structure to in vivo modeling of the tri-molecular complex, and identified structural interactions associated with activation of the ubiquitin ligase function.
View Article and Find Full Text PDFDFT study of GaAs quantum dot and 5CB liquid crystal molecule interaction.
J Mol Graph Model
January 2025
Institute of Chemical Physics after A.B. Nalbandyan of NAS RA, 5/2 P. Sevak St., Yerevan, 0014, Armenia.
Liquid crystals (LC) are widely used in various optical devices due to their birefringence, dielectric anisotropy, and responsive behavior to external fields. Enhancing the properties of existing LCs through doping with nanoparticles, including semiconductor quantum dots, offers a promising route for improving their performance. Among various nanoparticles, QDs stand out for their high charge mobility, sensitivity in the near-infrared spectral region, and cost-effectiveness.
View Article and Find Full Text PDFNon-surgical correction of an adult Class II high-angle with occlusal plane cant by four compromised permanent first molars extraction, preadjusted lingual appliance and miniscrews: A case report.
Int Orthod
January 2025
Private Practice, Osaka, Japan.
This case report describes a complex full-step asymmetrical Class II division 1 high-angle in an adult patient treated by extraction of compromised first molars with a preadjusted lingual appliance. Since the patient presented severe sagittal and vertical discrepancies combined with an Izard orthofrontal profile with upper lip protrusion, an extraction camouflage was performed with the twofold aim of obtaining ideal occlusal relationship and profile improvement, correcting occlusal plane cant by selective intrusion with interradicular miniscrews. Appropriate biomechanical strategies, including extraction choice and anchorage control during space closure, were needed to achieve the planned results.
View Article and Find Full Text PDFQuantitative analysis of particle behavior constituting multiple coherent structures in liquid bridges.
J Colloid Interface Sci
January 2025
Department of Mechanical and Aerospace Engineering, Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, 278-8510, Chiba, Japan. Electronic address:
Hypothesis: Coherent structures by low-Stokes-number particles are induced within a closed flow, in which ordered flow regions known as Kolmogorov-Arnold-Moser (KAM) tori emerge. A variety of structures with different spatial characteristics has been predicted by varying the Stokes number, whereas the coexistence of structures in flow suspending various types of particles has not been hitherto demonstrated.
Experiments: Half-zone liquid bridges of O () are prepared as a closed system to induce thermocapillary-driven time-dependent flow under normal gravity conditions.
Want AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!