Results 11 to 20 of about 36,028 (257)

Evaluation of ocular accommodation, convergence and fusional vergence changes during Ramadan [PDF]

Journal of Fasting and Health, 2013
Purpose: There are a few researches regarding the effects of Islamic fasting on visual system. The aim of this study was to investigate the effects of Ramadan fasting on the amplitude of accommodation (AA), near point of convergence (NPC), positive and ...
Seyed Hosein Hoseini-Yazdi, Ebrahim Jafarzadehpur, Ali Mirzajani, Mohsen Nematy   +3 more
doaj   +5 more sources

Axial length changes during accommodation in myopes and emmetropes [PDF]

, 2010
Purpose: To investigate the influence of accommodation upon axial length (and a comprehensive range of ocular biometric parameters), in populations of young adult myopic and emmetropic subjects.
Cheong, Shiow Huoy, Collins, Michael, Read, Scott, Woodman, Emily   +3 more
core   +1 more source

Mechanism of accommodation: A review of theoretical propositions

African Vision and Eye Health, 2015
Accommodation is the process by which the human eye changes its focus to see objects at varying distances from the eye. For nearly 300 years, scientists have investigated and presented various views on the mechanism of accommodation.
Godwin O. Ovenseri-Ogbomo, Olalekan A. Oduntan   +1 more
doaj   +1 more source

New methodology to measure the dynamics of ocular wave front aberrations during small amplitude changes of accommodation [PDF]

, 2007
We present a methodology to measure the systematic changes of aberrations induced by small changes in amplitude of accommodation. We use a method similar the one used in electrophysiology, where a periodic stimulus is presented to the eye and many ...
Arden, G., Diaz-Santana, L., Gruppetta, S., Guériaux, V.   +3 more
core   +1 more source

Semi‐supervised classification of fundus images combined with CNN and GCN

Journal of Applied Clinical Medical Physics, Volume 23, Issue 12, December 2022., 2022
Abstract Purpose Diabetic retinopathy (DR) is one of the most serious complications of diabetes, which is a kind of fundus lesion with specific changes. Early diagnosis of DR can effectively reduce the visual damage caused by DR. Due to the variety and different morphology of DR lesions, automatic classification of fundus images in mass screening can ...
Sixu Duan, Pu Huang, Min Chen, Ting Wang, Xiaolei Sun, Meirong Chen, Xueyuan Dong, Zekun Jiang, Dengwang Li   +8 more
wiley   +1 more source

COMP Report: CPQR technical quality control guidelines for use of positron emission tomography/computed tomography in radiation treatment planning

Journal of Applied Clinical Medical Physics, Volume 23, Issue 12, December 2022., 2022
Abstract Positron emission tomography with x‐ray computed tomography (PET/CT) is increasingly being utilized for radiation treatment planning (RTP). Accurate delivery of RT therefore depends on quality PET/CT data. This study covers quality control (QC) procedures required for PET/CT for diagnostic imaging and incremental QC required for RTP.
Ran Klein, Mike Oliver, Dan La Russa, John Agapito, Stewart Gaede, JeanPierre Bissonnette, Arman Rahmim, Carlos Uribe   +7 more
wiley   +1 more source

Uniqueness of radiomic features in non‐small cell lung cancer

Journal of Applied Clinical Medical Physics, Volume 23, Issue 12, December 2022., 2022
Abstract Purpose The uniqueness of radiomic features, combined with their reproducibility, determines the reliability of radiomic studies. This study is to test the hypothesis that radiomic features extracted from a defined region of interest (ROI) are unique to the underlying structure (e.g., tumor). Approach Two cohorts of non‐small cell lung cancer (
Gary Ge, Jie Zhang
wiley   +1 more source

Uncertainty propagation and sensitivity analysis: results from the Ocular Mathematical Virtual Simulator [PDF]

, 2021
We propose an uncertainty propagation study and a sensitivity analysis with the Ocular Mathematical Virtual Simulator, a computational and mathematical model that predicts the hemodynamics and biomechanics within the human eye. In this contribution, we focus on the effect of intraocular pressure, retrolaminar tissue pressure and systemic blood pressure
arxiv   +1 more source

Evaluation of intrafraction couch shifts for proton treatment delivery in head‐and‐neck cancer patients: Toward optimal imaging frequency

Journal of Applied Clinical Medical Physics, Volume 23, Issue 12, December 2022., 2022
Abstract Purpose Treatment planning for head‐and‐neck (H&N) cancer, in particular oropharynx, nasopharynx, and paranasal sinus cases, at our center requires noncoplanar proton beams due to the complexity of the anatomy and target location. Targeting accuracy for all beams is carefully evaluated by using image guidance before delivering proton beam ...
Nrusingh C. Biswal, Dario B. Rodrigues, Weiguang Yao, Jason K. Molitoris, Matthew E. Witek, Shifeng Chen   +5 more
wiley   +1 more source

Objective Amplitude of Accommodation Computed from Optical Quality Metrics Applied to Wavefront Outcomes

Journal of Optometry, 2009
Purpose: We studied the accuracy and precision of 32 objective wavefront methods for finding the amplitude of accommodation obtained in 180 eyes. Methods: Ocular accommodation was stimulated with 0.5 D steps in target vergence spanning the full range of ...
Norberto López-Gil, Vicente Fernández-Sánchez, Larry N. Thibos, Robert Montés-Micó   +3 more
doaj   +1 more source