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Astigmatisms

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https://www.readbyqxmd.com/read/29140824/beginnings-of-astigmatism-understanding-and-management-in-the-19th-century
#1
Andrzej Grzybowski, Piotr Kanclerz
Within the last 200 years, the perception of astigmatism has evolved from that of an infrequent and peculiar defect of the eye to a distortion almost as common as spherical refractive errors. Most of the significant findings on this condition were made in the 19th century, including the first description by Thomas Young (1773-1829) and the introduction of the treatment methods used today. The purpose of this study was to investigate the milestones in the understanding and management of astigmatism that occurred up to the year 1900...
November 14, 2017: Eye & Contact Lens
https://www.readbyqxmd.com/read/29140816/the-role-of-small-incision-suture-less-cataract-surgery-in-the-developed-world
#2
Sanduk Ruit, Reeta Gurung, Shyam Vyas
PURPOSE OF REVIEW: Manual small incision cataract surgery (MSICS) has recently gone through much refinement and fine tuning. It is often taken as an alternate option for phacoemulsification, especially in developing country. This review will present some insight on its applications especially for developed nations. The role of MSCIS in tackling complex cataracts with stony hard nucleus is fairly established. The role of training residents with MSCIS has certain advantages though debatable...
November 14, 2017: Current Opinion in Ophthalmology
https://www.readbyqxmd.com/read/29138533/comparison-of-visual-outcomes-after-bilateral-implantation-of-a-diffractive-trifocal-intraocular-lens-and-blended-implantation-of-an-extended-depth-of-focus-intraocular-lens-with-a-diffractive-bifocal-intraocular-lens
#3
André Lins de Medeiros, André Gustavo de Araújo Rolim, Antonio Francisco Pimenta Motta, Bruna Vieira Ventura, César Vilar, Mário Augusto Pereira Dias Chaves, Pedro Carlos Carricondo, Wilson Takashi Hida
Purpose: The purpose of this study was to compare the visual outcomes and subjective visual quality between bilateral implantation of a diffractive trifocal intraocular lens, Alcon Acrysof IQ(®) PanOptix(®) TNFT00 (group A), and blended implantation of an extended depth of focus lens, J&J Tecnis Symfony(®) ZXR00 with a diffractive bifocal intraocular lens, J&J Vision Tecnis(®) ZMB00 (group B). Methods: This prospective, nonrandomized, consecutive, comparative study included the assessment of 40 eyes in 20 patients implanted with multifocal intraocular lens...
2017: Clinical Ophthalmology
https://www.readbyqxmd.com/read/29137074/refractive-state-and-optical-compositions-of-preterm-children-with-and-without-retinopathy-of-prematurity-in-the-first-6-years-of-life
#4
Xiaohui Zhu, Rulian Zhao, Yang Wang, Lijuan Ouyang, Jing Yang, Yong Li, Lianhong Pi
This study aimed to investigate the refractive state and optical compositions of preterm children with and without mild retinopathy of prematurity (ROP) and explore the influence of prematurity and mild ROP on the development of refractive state and optical compositions.Preterm children who received fundus screening were recruited, and divided into ROP group and non-ROP group. Term children matched in age were also recruited as controls. Several correspondence indicators were measured before and after ciliary muscle paralysis with 1% cyclopentanone...
November 2017: Medicine (Baltimore)
https://www.readbyqxmd.com/read/29135603/role-of-hemidivisional-corneal-topographic-astigmatisms-corts-in-the-regularization-and-reduction-of-irregular-astigmatism
#5
Noel Alpins, James K Y Ong, George Stamatelatos
PURPOSE: To demonstrate how the concept of hemidivisional corneal topographic astigmatism (hemiCorT) enables the planning of hemidivisional corneal treatments to reduce irregularity and overall astigmatism. METHODS: Whole-of-cornea corneal topographic astigmatism (CorT) is calculated from topography data derived from a corneal topographer or tomographer. The cornea is conceptually divided into 2 hemidivisions along the flat meridian of the CorT. For each hemidivision, hemiCorTs are calculated...
November 9, 2017: Cornea
https://www.readbyqxmd.com/read/29134322/correlative-factors-analysis-of-postural-related-ocular-cyclotorsion-with-image-guided-system
#6
Fangkun Zhao, Ling Li, Wenkai Zhou, Dong Shi, Yu Fan, Liwei Ma
PURPOSE: To explore the correlation between ocular cyclotorsion induced by sitting and supine positions as well as other selected factors, validated by an image-guided system. STUDY DESIGN: A cross-sectional study conducted in 73 inpatients (85 eyes) who received intraocular operations in China Medical University. METHODS: The ocular cyclotorsion degree was recorded using an image-guided system (Verion Reference Unit, Alcon) by comparing images captured in sitting position, as well as pre- and post-different anesthesia methods in the supine position...
November 13, 2017: Japanese Journal of Ophthalmology
https://www.readbyqxmd.com/read/29131197/astigmatism-free-czerny-turner-compact-spectrometer-with-cylindrical-mirrors
#7
Guo Xia, Su Wu, Guodong Wang, Mingyong Hu, Jinyu Xing
A modified optical design for a broadband, high resolution, astigmatism-free Czerny-Turner spectrometer is proposed. Astigmatism is corrected by using cylindrical mirrors over a broad spectral range. The theory and method for astigmatism correction are thoroughly analyzed. The comparison between the modified Czerny-Turner spectrometer and the traditional Czerny-Turner spectrometer is also described in detail. The ray-tracing results show that the RMS spot radius has decreased to 4.2 μm at the central wavelength and 17 μm at the wedge wavelength...
November 10, 2017: Applied Optics
https://www.readbyqxmd.com/read/29131195/compact-single-shot-d-scan-setup-for-the-characterization-of-few-cycle-laser-pulses
#8
Maïté Louisy, Chen Guo, Lana Neoričić, Shiyang Zhong, Anne L'Huillier, Cord L Arnold, Miguel Miranda
We present a compact implementation of the ultrashort pulse measurement technique based on dispersion scans (d-scan), allowing single-shot measurement of few-cycle pulses. The main novelty in our design, making our setup extremely compact and simple, is the use, after a prism, of a spherical mirror in an off-axis geometry. The intentionally introduced strong astigmatism makes it possible to image the output of the crystal in one direction while focusing it in the other direction, resulting in the output face of the prism being imaged into a line in the second-harmonic crystal...
November 10, 2017: Applied Optics
https://www.readbyqxmd.com/read/29125149/sia-formula-an-easy-way-to-calculate-surgically-induced-astigmatism
#9
S Sánchez-Tabernero
No abstract text is available yet for this article.
November 10, 2017: Eye
https://www.readbyqxmd.com/read/29124780/refractive-error-and-vision-correction-in-a-general-sports-playing-population
#10
Fabrizio Zeri, Sabrina Pitzalis, Assunta Di Vizio, Tiziana Ruffinatto, Fabrizio Egizi, Francesco Di Russo, Richard Armstrong, Shehzad A Naroo
PURPOSE: To evaluate, in an amateur sports-playing population, the prevalence of refractive error, the type of vision correction used during sport and attitudes toward different kinds of vision correction used in various types of sports. METHOD: A questionnaire was used for people engaging in sport and data was collected from sport centres, gyms and universities that focused on the motor sciences. RESULTS: One thousand, five hundred and seventy-three questionnaires were collected (mean age 26...
November 9, 2017: Clinical & Experimental Optometry: Journal of the Australian Optometrical Association
https://www.readbyqxmd.com/read/29120975/refractive-error-in-a-sample-of-black-high-school-children-in-south-africa
#11
Samuel Otabor Wajuihian, Rekha Hansraj
SIGNIFICANCE: This study focused on a cohort that has not been studied and who currently have limited access to eye care services. The findings, while improving the understanding of the distribution of refractive errors, also enabled identification of children requiring intervention and provided a guide for future resource allocation. PURPOSE: The aim of conducting the study was to determine the prevalence and distribution of refractive error and its association with gender, age, and school grade level...
November 9, 2017: Optometry and Vision Science: Official Publication of the American Academy of Optometry
https://www.readbyqxmd.com/read/29120715/new-pinhole-sulcus-implant-for-the-correction-of-irregular-corneal-astigmatism
#12
Claudio C Trindade, Bruno C Trindade, Fernando C Trindade, Liliana Werner, Robert Osher, Marcony R Santhiago
PURPOSE: To evaluate the effect on visual acuity of the implantation of a new intraocular pinhole device (Xtrafocus) in cases of irregular corneal astigmatism with significant visual impairment. SETTING: University of São Paulo, São Paulo, Brazil. DESIGN: Prospective case series. METHODS: Pseudophakic eyes of patients with irregular corneal astigmatism were treated with the pinhole device. The causes of irregular corneal astigmatism were keratoconus, post radial keratotomy (RK), post-penetrating keratoplasty (PKP), and traumatic corneal laceration...
October 2017: Journal of Cataract and Refractive Surgery
https://www.readbyqxmd.com/read/29118489/minimal-duration-cataract-surgery-with-oblique-limbal-stab-incision-technique
#13
Deepti Mahajan, Ram Lal Sharma, Kulbhushan Prakash Chaudhary
PURPOSE: Small incision cataract surgery (SICS) and phacoemulsification with oblique limbal stab incision technique were studied and compared. SETTING: The study was conducted in the Department of Ophthalmology, Indira Gandhi Medical College, Shimla, for 1 year. DESIGN: This was a prospective randomized study. METHODS: One hundred patients undergoing SICS (6-7 mm) were compared with another age- and sex-matched 100 patients undergoing phaco (2...
September 2017: Oman Journal of Ophthalmology
https://www.readbyqxmd.com/read/29117415/risk-factors-for-opaque-bubble-layer-in-small-incision-lenticule-extraction-smile
#14
Liuyang Li, Julie M Schallhorn, Jiaonan Ma, Lin Zhang, Rui Dou, Yan Wang
PURPOSE: To assess the independent effect of myopia and astigmatism on the risk of the occurrence of opaque bubble layer (OBL) in small incision lenticule extraction (SMILE) and further investigate the relationship between scanning depth and OBL. METHODS: Twenty-two cases and 317 controls were included in a case-control study from the database of Tianjin Eye Hospital from April 2015 to July 2016. Baseline characteristics were recorded and all of the eyes were manually reviewed by two different observers masked to preoperative refractive status...
November 1, 2017: Journal of Refractive Surgery
https://www.readbyqxmd.com/read/29117411/assessing-the-likely-effect-of-posterior-corneal-curvature-on-toric-iol-calculation-for-iols-of-2-50-d-or-greater-cylinder-power
#15
Benjamin R LaHood, Michael Goggin, Adrian Esterman
PURPOSE: To establish whether average refractive overcorrection or undercorrection of corneal astigmatism based on the orientation (rule) of the astigmatism occurs if toric intraocular lenses (IOLs) are calculated on the basis of anterior corneal measurements in eyes requiring toric IOL cylinder power of 2.50 diopters (D) or greater. METHODS: One hundred thirteen consecutive eyes with anterior corneal keratometric astigmatism requiring IOL cylinder power of 2.50 D or greater underwent phacoemulsification with IOL powers calculated using anterior corneal curvature data alone...
November 1, 2017: Journal of Refractive Surgery
https://www.readbyqxmd.com/read/29116549/transepithelial-accelerated-corneal-collagen-cross-linking-with-higher-oxygen-availability-for-keratoconus-1-year-results
#16
Ling Sun, Meng Li, Xiaoyu Zhang, Mi Tian, Tian Han, Jing Zhao, Xingtao Zhou
PURPOSE: To investigate the safety and efficacy of a new protocol for transepithelial accelerated corneal collagen cross-linking with higher oxygen availability for keratoconus treatment. METHODS: There were 26 patients (26 eyes) diagnosed with keratoconus enrolled in the study and treated with transepithelial accelerated corneal collagen cross-linking. The corneas were irradiated using UVA light for 5 min and 20 s with 45 mW/cm(2) irradiance and pulsed illumination (1:1)...
November 7, 2017: International Ophthalmology
https://www.readbyqxmd.com/read/29109892/topography-and-higher-order-corneal-aberrations-of-the-fellow-eye-in-unilateral-keratoconus
#17
Sibel Aksoy, Sezen Akkaya, Yelda Özkurt, Sevda Kurna, Banu Açıkalın, Tomris Şengör
Objectives: Comparison of topography and corneal higher order aberrations (HOA) data of fellow normal eyes of unilateral keratoconus patients with keratoconus eyes and control group. Materials and Methods: The records of 196 patients with keratoconus were reviewed. Twenty patients were identified as unilateral keratoconus. The best corrected visual acuity (BCVA), topography and aberration data of the unilateral keratoconus patients' normal eyes were compared with their contralateral keratoconus eyes and with control group eyes...
October 2017: Turkish Journal of Ophthalmology
https://www.readbyqxmd.com/read/29095754/cross-sectional-and-longitudinal-investigation-of-the-power-vector-in-astigmatism-the-yamagata-study-funagata
#18
Hiroyuki Namba, Ryo Kawasaki, Akira Sugano, Katsuhiro Nishi, Takanori Murakami, Koichi Nishitsuka, Takeo Kato, Takamasa Kayama, Hidetoshi Yamashita
PURPOSE: To investigate how age and other factors affect astigmatism in Japanese adults over a period of 5 years. METHODS: We included 512 Japanese participants who had undergone systemic and ophthalmological examinations both in 2005-2007 and in 2010-2012 in Funagata town, Yamagata, Japan. Astigmatism was evaluated using power vector analyses, where J0 represents the power of orthogonal astigmatism. Positive values of J0 indicate with-the-rule astigmatism, whereas negative values indicate against-the-rule (ATR)...
October 31, 2017: Cornea
https://www.readbyqxmd.com/read/29095753/effect-of-suture-removal-on-refraction-and-graft-curvature-after-deep-anterior-lamellar-keratoplasty-in-patients-with-keratoconus
#19
Sepehr Feizi, Mohammad Ali Javadi, Nazanin Behnaz, Sadaf Fani-Hanife, Mohammad Reza Jafarinasab
PURPOSE: To evaluate the effect of suture removal on refraction and keratometry measurements after deep anterior lamellar keratoplasty (DALK). METHODS: This retrospective study enrolled 54 keratoconus-affected eyes that underwent DALK. A combined suturing technique consisting of a 16-bite single running and 8-bite interrupted 10-0 nylon sutures was used at the time of keratoplasty. Selective interrupted suture removal was performed in a subgroup of patients to reduce postkeratoplasty astigmatism...
October 31, 2017: Cornea
https://www.readbyqxmd.com/read/29090512/corneal-backward-scattering-and-higher-order-aberrations-in-children-with-vernal-keratoconjunctivitis-and-normal-topography
#20
Tommy C Y Chan, Emily S Wong, Jason C K Chan, Yumeng Wang, Marco Yu, Naoyuki Maeda, Vishal Jhanji
PURPOSE: To investigate the corneal backward scattering and higher-order aberrations (HOAs) in children with vernal keratoconjunctivitis (VKC) and normal topography. METHODS: Thirty-six eyes of 22 patients with VKC and 54 eyes of 34 normal subjects were included. All participants had clear cornea, absence of dry eyes and a normal corneal tomography. Scheimpflug imaging was used to measure corneal backward scattering in zones centred on the corneal apex (central 2-mm zone and paracentral 2- to 6-mm zone), and HOAs were compared between VKC and normal control...
November 1, 2017: Acta Ophthalmologica
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