Abstract:
:The practical advantages of quantifying an angle by a ratio of linear lengths instead of arcs of circles has led to the definition of the prism-diopter, a conventional unity for numbering prisms and measuring strabismic deviations. However, a major inconvenience of using prism-diopter unities to express angular measurements is the non-linearity of the scale, which reaches an infinite value for the angle of 90º, then becomes negative, with decreasing magnitudes for increasing angles between 90º and 180º. As a consequence, arithmetical operations and comparisons of angles measured by such unities present errors of very great magnitudes. In order to retain the advantages of defining an angle by straight line dimensions but to diminish the severe inconveniences of this method, a new definition of the prism-diopter is proposed. Here, instead of defining the prism-diopter by the asymmetrical condition, the conception of this new unity is based on a geometrically symmetrical condition; that of the relationship of an isosceles triangle (where the leg is perpendicular to the bisector of the angle and the bisector itself ). The condition of symmetry for the definition of the new unity represents a conceptual advance because it reproduces the already well accepted, conventional criteria for quantifying the value of a prism, that of its minimum deviation. Furthermore, it corresponds to the most commonly observed clinical conditions of binocular balance. The absolute differences between the unitary values of the prism-diopter and that of the new unity are negligible (0.0025%), but the scale of values expressed by the new unity is closer to the ideal scale of angular measurements. (With the new unity, the infinite value is only reached for an angle of 180º and the errors due to arithmetical operations are much smaller.) Numerical examples showing the advantages of using the new unity of angular measurements instead of the prism-diopter are presented. A mathematical generalization of the modifying concept (partition of an angle) with which the new unity is based is also provided.
journal_name
Arq Bras Oftalmoljournal_title
Arquivos brasileiros de oftalmologiaauthors
Bicas HEdoi
10.5935/0004-2749.20140070subject
Has Abstractpub_date
2014-10-01 00:00:00pages
275-279issue
5eissn
0004-2749issn
1678-2925pii
S0004-27492014000500275journal_volume
77pub_type
杂志文章abstract:PURPOSE:Cataract is considered the main preventable cause of blindness and visual impairment mainly in poor countries. This study was done to evaluate if cataract is still an important cause of blindness in Central-West region of State of São Paulo, Brazil. METHODS:A cross-sectional study was conducted with a systemat...
journal_title:Arquivos brasileiros de oftalmologia
pub_type: 杂志文章
doi:10.1590/s0004-27492009000300018
更新日期:2009-05-01 00:00:00
abstract::Retinoschisis is an abnormal separation of the retinal layers and is asymptomatic in most cases. Enlargement of the area of retinoschisis and retinal tear and detachment are possible complications of the disease, and the treatment of retinoschisis is controversial. In this case report, we present a case of retinal det...
journal_title:Arquivos brasileiros de oftalmologia
pub_type: 杂志文章
doi:10.5935/0004-2749.20150014
更新日期:2015-01-01 00:00:00
abstract::In this report, we describe an unusual patient with a choreiform movement disorder, misdiagnosed as Huntington disease, who later developed dense vitreitis leading to the identification of Treponema pallidum as the underlying pathogen of both abnormalities. ...
journal_title:Arquivos brasileiros de oftalmologia
pub_type: 杂志文章
doi:10.1590/s0004-27492008000500020
更新日期:2008-09-01 00:00:00
abstract:Purpose::To compare central corneal thickness (CCT) measurements of healthy individuals obtained with ultrasonic pachymetry (UP) and non-contact specular microscopy (NCSM). Method::In total, 148 eyes of 74 subjects with no ocular or systemic diseases were included in the study. Central corneal thickness measurements o...
journal_title:Arquivos brasileiros de oftalmologia
pub_type: 杂志文章
doi:10.5935/0004-2749.20160089
更新日期:2016-09-01 00:00:00
abstract:INTRODUCTION:The treatment of glaucoma is made initially with the use of eyedrops, with the purpose to decrease intraocular pressure and to minimize the damages to the optic nerve. The lack of compliance with drug therapy can be influenced by factors related to patients, doctors and medicines. PURPOSES:To estimate the...
journal_title:Arquivos brasileiros de oftalmologia
pub_type: 杂志文章
doi:10.1590/s0004-27492008000200014
更新日期:2008-03-01 00:00:00
abstract:PURPOSE:To correlate provocative test-based intraocular pressure (IOP) variation parameters (fluctuation and peak) with functional status, and to compare these IOP parameters between treated eyes with asymmetric primary open-angle glaucoma (POAG). METHODS:A prospective observational study including consecutively treat...
journal_title:Arquivos brasileiros de oftalmologia
pub_type: 杂志文章
doi:10.5935/0004-2749.20190035
更新日期:2019-05-01 00:00:00
abstract:PURPOSE:To analyze the clinical outcomes of the ocular surface in patients with vitamin D deficiency after oral replacement. METHODS:A total of 40 patients with vitamin D deficiency were enrolled in the study. The patients received 50,000 units of oral vitamin D weekly over a period of 8 weeks. After 8 weeks, 1,500-2,...
journal_title:Arquivos brasileiros de oftalmologia
pub_type: 杂志文章
doi:10.5935/0004-2749.20200043
更新日期:2020-08-01 00:00:00
abstract::Interferon and ribavirin are medications widely used in the treatment of some systemic diseases, mainly hepatitis C. Ribavirin when associated with interferon increases the rate of success of this treatment. There are about 170 million patients with chronic hepatitis C in the world, many in use of these medications. T...
journal_title:Arquivos brasileiros de oftalmologia
pub_type: 杂志文章
doi:10.1590/s0004-27492006000400028
更新日期:2006-07-01 00:00:00
abstract:PURPOSE:To compare artificial eye amplitudes in enucleated socket with porous polyethylene either spherical or quad-motility implant and study the characteristics of artificial eyes fit with the two orbital implants. METHODS:A total of 21 patients were prospectively studied who underwent enucleation because of an intr...
journal_title:Arquivos brasileiros de oftalmologia
pub_type: 杂志文章,随机对照试验
doi:10.1590/s0004-27492007000500019
更新日期:2007-09-01 00:00:00
abstract::The authors report a case of arteriolar retinal macrovessel, diagnosed by routine ophthalmologic examination, as well as its optic coherence tomography aspects. Congenital retinal macrovessel is a large aberrant vessel, often unilateral, usually a vein, rarely an artery, located in the posterior pole which can cross t...
journal_title:Arquivos brasileiros de oftalmologia
pub_type: 杂志文章
doi:10.1590/s0004-27492007000100031
更新日期:2007-01-01 00:00:00
abstract:PURPOSES:To evaluate changes in ocular blood flow and subfoveal choroidal thickness in patients with symptomatic carotid artery stenosis after carotid artery stenting. METHODS:We included 15 men (mean age, 63.6 ± 9.1 years) with symptomatic carotid artery stenosis and 18 healthy volunteers (all men; mean age, 63.7 ± 5...
journal_title:Arquivos brasileiros de oftalmologia
pub_type: 杂志文章
doi:10.5935/0004-2749.20200081
更新日期:2020-09-01 00:00:00
abstract:PURPOSE:The present study's aim was to compare the biomechanical properties of corneal tissue in patients who underwent deep anterior lamellar keratoplasty (DALK) surgery, with successful big bubble formation and manual lamellar dissection, during failed big bubble formation. METHODS:This retrospective comparative stu...
journal_title:Arquivos brasileiros de oftalmologia
pub_type: 杂志文章
doi:10.5935/0004-2749.20200022
更新日期:2020-03-01 00:00:00
abstract:PURPOSE:To investigate the reliability of ultrasound in determining the size and identify the sonographic features and artifacts generated by intraocular foreign bodies of different materials. METHODS:Experimental study using 36 enucleated porcine eyes. Fragments of nine different compositions (wood, glass, plastic, c...
journal_title:Arquivos brasileiros de oftalmologia
pub_type: 杂志文章
doi:10.1590/s0004-27492013000100005
更新日期:2013-01-01 00:00:00
abstract::The point of centration for refractive surgery is a theme of great importance that generates considerable discussion among specialists and surgeons in the field. Notably, any changes in light can alter the size of the pupil, and the visual axis of the fixation line to the fovea is unique in each patient. A variety of ...
journal_title:Arquivos brasileiros de oftalmologia
pub_type: 杂志文章,评审
doi:10.5935/0004-2749.20200014
更新日期:2020-01-01 00:00:00
abstract::Vitreous cyst is a rare condition of the posterior segment of the eye. It can occur in eyes with coexistent ocular diseases or in eyes that are otherwise normal. This study reports a case of vitreous cyst in a patient with retinitis pigmentosa and presents its clinical and ultrasonographic features. ...
journal_title:Arquivos brasileiros de oftalmologia
pub_type: 杂志文章
doi:10.1590/s0004-27492010000200016
更新日期:2010-03-01 00:00:00
abstract::Report on the development of pseudohypopyon immediately after intravitreal injection of triamcinolone acetonide (TAAC). Two phakic patients presenting with a transient pseudohypopyon after having been treated with intravitreal triamcinolone. One had a clinically significant macular edema with cystoid component (CSME w...
journal_title:Arquivos brasileiros de oftalmologia
pub_type: 杂志文章
doi:10.1590/s0004-27492005000200018
更新日期:2005-03-01 00:00:00
abstract:PURPOSE:To evaluate the correlation between the preoperative visual acuity (VA) obtained by the potential acuity meter (PAM) and the postoperative VA in a patient submitted to cataract surgery, as well as its correlation with the dominant morphologic classification of the cataract. METHODS:This is a prospective study ...
journal_title:Arquivos brasileiros de oftalmologia
pub_type: 杂志文章
doi:10.1590/s0004-27492008000600007
更新日期:2008-11-01 00:00:00
abstract::Vogt-Koyanagi-Harada syndrome is chronic systemic autoimmune disease with ocular, nervous, auditory and tegumental manifestations. We report here the case of a child with onset of symptoms at four years and two months of age, with positive HLA DRB1*01. ...
journal_title:Arquivos brasileiros de oftalmologia
pub_type: 杂志文章
doi:10.1590/s0004-27492007000200027
更新日期:2007-03-01 00:00:00
abstract::Nature has always provided an unlimited source of biologically-active compounds. Since the beginning of mankind, humans have sought resources in fauna and flora to treat eye diseases. However, it was only after the Industrial Revolution that extracts of plants and substances of animal origin could be used safely, as h...
journal_title:Arquivos brasileiros de oftalmologia
pub_type: 杂志文章,评审
doi:10.5935/0004-2749.20180086
更新日期:2018-09-01 00:00:00
abstract:PURPOSE:To report a specific line of research developed at the University of São Paulo/Brazil on fibrin glue used for sealing corneal perforations and the perspectives of use on non-perforated corneal ulcers and photorefractive keratectomy-operated corneas. METHODS:To describe fibrin glue manufacture, development of a...
journal_title:Arquivos brasileiros de oftalmologia
pub_type: 杂志文章,评审
doi:10.1590/s0004-27492007000500029
更新日期:2007-09-01 00:00:00
abstract::Permanent visual loss can be caused by improper use of immunosuppressive therapy in cases of uveitis without differential diagnosis of syphilitic uveitis. We present four cases of syphilitic uveitis that were incorrectly diagnosed as being secondary to rheumatic diseases and were subsequently treated with immunosuppre...
journal_title:Arquivos brasileiros de oftalmologia
pub_type: 杂志文章
doi:10.5935/0004-2749.20150047
更新日期:2015-05-01 00:00:00
abstract:PURPOSE:To evaluate the RPS Adenodetector, a rapid immunochromatographic test, in the diagnosis of patients with clinical overt adenoviral conjunctivitis. METHODS:Consecutive case series. Patients underwent conjunctiva scraping for RPS Adenodetector test and culture to identify adenovirus. RESULTS:A total of 11 patie...
journal_title:Arquivos brasileiros de oftalmologia
pub_type: 杂志文章
doi:10.1590/s0004-27492007000300010
更新日期:2007-05-01 00:00:00
abstract:PURPOSE:To determine the incidence of positive corneoscleral rim cultures preserved in Optisol GS medium, to identify pathogens involved and possible recipient eye infection. METHODS:A hundred sixty-three corneoscleral rim cultures penetrating keratoplasties performed from January 2001 to January 2003 in the Hospital ...
journal_title:Arquivos brasileiros de oftalmologia
pub_type: 杂志文章
doi:10.1590/s0004-27492008000100003
更新日期:2008-01-01 00:00:00
abstract::To report a case of gyrate atrophy of the choroid and retina associated with retinal detachment. Hyperornithinemia confirmed the diagnosis of gyrate atrophy. Pars plana vitrectomy with silicone oil infusion was performed with good anatomical results, despite the persistence of low visual acuity. Retinal detachment is ...
journal_title:Arquivos brasileiros de oftalmologia
pub_type: 杂志文章
doi:10.1590/s0004-27492012000100012
更新日期:2012-01-01 00:00:00
abstract::Here we report a case of childhood glaucoma refractory to angle and trabeculectomy surgery. The patient was treated with an Ahmed™ drainage implant that was subsequently complicated by rapid-onset panophthalmitis and orbital cellulitis. Intravenous and intravitreal antibiotic therapy was initiated and the drainage tub...
journal_title:Arquivos brasileiros de oftalmologia
pub_type: 杂志文章
doi:10.5935/0004-2749.20160037
更新日期:2016-04-01 00:00:00
abstract:PURPOSE:To evaluate the feasibility of the combined use of bevacizumab (Avastin®) and combined with infliximab (Remicade®) in the treatment of naive choroidal neovascularization due to age-related macular degeneration eyes. METHODS:Intravitreal injections of bevacizumab combined with infliximab in 6 neovascular age-re...
journal_title:Arquivos brasileiros de oftalmologia
pub_type: 杂志文章
doi:10.1590/s0004-27492013000300010
更新日期:2013-05-01 00:00:00
abstract:PURPOSE:To describe the electroretinogram of the South-American opossum (Didelphis aurita) obtained by chromatic stimulus of specific wavelengths. The electroretinogram records voltage variations of retinal cells triggered by light stimulation. The electroretinogram represents the combination of electric activity of ma...
journal_title:Arquivos brasileiros de oftalmologia
pub_type: 杂志文章
doi:10.1590/s0004-27492006000600014
更新日期:2006-11-01 00:00:00
abstract:PURPOSE:To evaluate refractional astigmatism prevalence and its relationship with grating acuity in a cohort of non-verbal children. METHODS:482 normal children, aged from 2 to 36 months, were submitted to ophthalmological examination. Fourteen subjects were excluded due to ocular disease and the sample remained with ...
journal_title:Arquivos brasileiros de oftalmologia
pub_type: 杂志文章
doi:10.1590/s0004-27492006000300015
更新日期:2006-05-01 00:00:00
abstract::We describe the case of a 23-month-old female infant with a diagnosis of hemolytic uremic syndrome (HUS) and hemorrhagic retinopathy. The patient had a past history of abdominal pain, bloody diarrhea, and acute renal failure. On ophthalmologic examination, indirect ophthalmoscopy revealed extensive areas of flame-shap...
journal_title:Arquivos brasileiros de oftalmologia
pub_type: 杂志文章
doi:10.5935/0004-2749.20140099
更新日期:2014-11-01 00:00:00
abstract:PURPOSE:To assess the resources use, costs and effectiveness of non-penetrating deep sclerectomy (NPDS). METHODS:A retrospective cohort of NPDS patients was analyzed. Eyes were stratified according to glaucoma severity into 3 groups: 1 (early), 2 (moderate) and 3 (severe). NPDS associated resources were based on the f...
journal_title:Arquivos brasileiros de oftalmologia
pub_type: 杂志文章
doi:10.1590/s0004-27492011000600003
更新日期:2011-11-01 00:00:00