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1.
Folia Med (Plovdiv) ; 62(1): 133-140, 2020 03 31.
Article in English | MEDLINE | ID: mdl-32337900

ABSTRACT

BACKGROUND: Broncho-pleural fistula (BPF) can occur after pulmonary resections as a complication with high morbidity and mortality rates. AIM: In the present study, we analyzed the relation between the possible risk factors and the two major bronchial closure techniques for BPF after lung resections, and the management methods of BPF. MATERIALS AND METHODS: A total of 26 cases detected and managed with BPF diagnosis in our clinic between September 2005 and September 2017 were evaluated retrospectively. The cases were divided into two groups: Group 1 (n=14); bronchial closure performed manually and Group 2 (n=12) bronchial closure with stapler. We analyzed cases for age, gender, body mass index, pulmonary function tests, time to fistula, total protein/albumin level, length of hospital stay, bronchial stump distance, presence of bronchial stump coverage, and the mean survivals. RESULTS: Twenty-three of the cases were males (88.5%) with a mean age of 60.03±8.7 years (range 38-73). While BPF was detected in twenty-three (88.5%) of the cases after pneumonectomy, three (11.5%) of them were after lobectomy. There was no statistically significant correlation between the two groups in gender, age, BMI, preoperative FEV1, time to fistula, total protein/albumin level, length of hospital stay, bronchial stump distance, and presence of bronchial stump coverage (chi-square test, p>0.05). As a result of the applied Kaplan-Meier analysis, we found no statistically significant difference in the mean survival rates between the two groups (p>0.05). CONCLUSIONS: Broncho-pleural fistulas still remains a major challenge. Although there is no statistical relationship between bronchial closure techniques and possible risk factors in our study, patients should be assessed in terms of possible risk factors. The management strategy for BPF varies according to individual patients' clinical condition, the size of the fistula, and development time.


Subject(s)
Bronchial Fistula/epidemiology , Pleural Diseases/epidemiology , Pneumonectomy/methods , Postoperative Complications/epidemiology , Surgical Stapling/statistics & numerical data , Suture Techniques/statistics & numerical data , Adult , Aged , Female , Humans , Male , Middle Aged , Risk Factors , Wound Closure Techniques/statistics & numerical data
2.
Nucl Med Commun ; 39(11): 995-1004, 2018 Nov.
Article in English | MEDLINE | ID: mdl-30188416

ABSTRACT

OBJECTIVE: Our aim was to assess the significance of metabolic positron emission tomography (PET) parameters for the prediction of occult mediastinal lymph node metastasis (OLM) and recurrence in patients with clinical-N0 nonsmall cell lung cancer (NSCLC) after surgical resection and lymph node dissection. MATERIALS AND METHODS: We evaluated 98 patients with NSCLC [52 adenocarcinoma (ADC), 46 squamous cell carcinoma (SQCC)] who had undergone initial/preoperative fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography (F-FDG PET/CT). Eligibility criteria for participation were clinically staged as N0 and no FDG uptake in mediastinal lymph nodes on preoperative PET/CT. Clinicopathological characteristics and the diagnosis of recurrence were obtained by reviewing the hospital records. Metabolic parameters [maximum standardized uptake value, mean standardized uptake value, metabolic tumor volume (MTV), total lesion glycolysis] were determined on F-FDG PET/CT images. The association of metabolic parameters with OLM and recurrence was assessed. RESULTS: OLM was found in 26 (26.53%) patients. T-stage, central location, and lymphovascular invasion were associated with OLM (respectively, P=0.007, 0.011, <0.001). None of the metabolic parameters was associated with OLM. Metabolic parameters of the tumor were significantly higher in patients with recurrence when the cohort was evaluated as a whole (P=0.002, 0.005, 0.016, and 0.004, respectively). In particular, there was a significant association between recurrence and tumor size, grade, stage, MTV (P<0.001), and TLG (P<0.001) in ADC. This association was not found in SQCC. Multivariate analysis showed that MTV was an independent prognostic factor for recurrence and associated with disease-free survival. CONCLUSION: Metabolic parameters of the primary tumor on preoperative F-FDG PET/CT could not predict OLM in patients with clinical-N0 NSCLC. MTV was an independent risk factor for recurrence in ADC, but not in SQCC.


Subject(s)
Carcinoma, Non-Small-Cell Lung/diagnostic imaging , Carcinoma, Non-Small-Cell Lung/metabolism , Fluorodeoxyglucose F18 , Lung Neoplasms/diagnostic imaging , Lung Neoplasms/metabolism , Positron Emission Tomography Computed Tomography , Adult , Aged , Carcinoma, Non-Small-Cell Lung/pathology , Carcinoma, Non-Small-Cell Lung/surgery , Female , Humans , Lung Neoplasms/pathology , Lung Neoplasms/surgery , Lymphatic Metastasis , Male , Middle Aged , Multivariate Analysis , Neoplasm Staging , Prognosis , ROC Curve , Retrospective Studies
3.
Eye (Lond) ; 31(8): 1221-1228, 2017 Aug.
Article in English | MEDLINE | ID: mdl-28430177

ABSTRACT

PurposeTo determine the prevalence of visual impairment and blindness in underserved Iranian villages and to identify the most common cause of visual impairment and blindness.Patients and methodsMultistage cluster sampling was used to select the participants who were then invited to undergo complete examinations. Optometric examinations including visual acuity, and refraction were performed for all individuals. Ophthalmic examinations included slit-lamp biomicroscopy and ophthalmoscopy. Visual impairment was determined according to the definitions of the WHO and presenting vision.ResultsOf 3851 selected individuals, 3314 (86.5%) participated in the study. After using the exclusion criteria, the present report was prepared based on the data of 3095 participants. The mean age of the participants was 37.6±20.7 years (3-93 years). The prevalence of visual impairment and blindness was 6.43% (95% confidence interval (CI): 3.71-9.14) and 1.18% (95% CI: 0.56-1.79), respectively. The prevalence of visual impairment varied from 0.75% in participants aged less than 5 years to 38.36% in individuals above the age of 70 years. Uncorrected refractive errors and cataract were the first and second leading causes of visual impairment; moreover, cataract and refractive errors were responsible for 35.90 and 20.51% of the cases of blindness, respectively.ConclusionThe prevalence of visual impairment was markedly high in this study. Lack of access to health services was the main reason for the high prevalence of visual impairment in this study. Cataract and refractive errors are responsible for 80% of visual impairments which can be due to poverty in underserved villages.


Subject(s)
Blindness/epidemiology , Medically Underserved Area , Vision, Low/epidemiology , Adolescent , Adult , Aged , Aged, 80 and over , Child , Child, Preschool , Cluster Analysis , Cross-Sectional Studies , Female , Humans , Iran/epidemiology , Logistic Models , Male , Middle Aged , Prevalence , Refractive Errors , Rural Population/statistics & numerical data , Young Adult
4.
East Mediterr Health J ; 22(9): 676-681, 2016 Dec 12.
Article in English | MEDLINE | ID: mdl-27966769

ABSTRACT

This study aimed to determine the trends in outpatient cataract surgery and its determinants in the Islamic Republic of Iran between 2006 and 2010. In this cross-sectional study, 106 cataract surgery centres were selected in all provinces by multistage randomized cluster sampling. The number of centres in each province was determined from the number of cataract operations and the number of patient charts examined in each centre was proportionate to the number of cataract operations in that centre. The prevalence of outpatient surgery increased from 46.0% (95% CI, 35.3-56.8) in 2006 to 51.4% (95% CI, 40.2-62.7) in 2010 (P = 0.549). Patients stayed in hospital for more than one night after 10.5% (95% CI, 6.9-14.1) of operations. Use of phacoemulsification and topical anaesthesia increased the prevalence of outpatient surgery and decreased intraoperative complications. Although outpatient cataract surgery increased by 11.7%, use of methods such as phacoemulsification is not widespread, and more attention should be paid to the barriers to outpatient cataract surgery in the Islamic Republic of Iran.


Subject(s)
Cataract Extraction/statistics & numerical data , Cataract Extraction/trends , Outpatients , Adolescent , Adult , Aged , Aged, 80 and over , Child , Cross-Sectional Studies , Female , Humans , Iran , Male , Medical Audit , Middle Aged , Young Adult
5.
East. Mediterr. health j ; 22(9): 676-681, 2016-09.
Article in English | WHO IRIS | ID: who-260347

ABSTRACT

This study aimed to determine the trends in outpatient cataract surgery and its determinants in the Islamic Republic of Iran between 2006 and 2010. In this cross-sectional study, 106 cataract surgery centres were selected in all provinces by multistage randomized cluster sampling. The number of centres in each province was determined from the number of cataract operations and the number of patient charts examined in each centre was proportionate to the number of cataract operations in that centre. The prevalence of outpatient surgery increased from 46.0% [95% CI, 35.3-56.8] in 2006 to 51.4% [95% CI, 40.2-62.7] in 2010 [P = 0.549]. Patients stayed in hospital for more than one night after 10.5% [95% CI, 6.9-14.1] of operations. Use of phacoemulsification and topical anaesthesia increased the prevalence of outpatient surgery and decreased intraoperative complications. Although outpatient cataract surgery increased by 11.7%, use of methods such as phacoemulsification is not widespread, and more attention should be paid to the barriers to outpatient cataract surgery in the Islamic Republic of Iran


La présente étude avait pour objectif de déterminer les tendances de la chirurgie de la cataracte en ambulatoire et ses déterminants en République islamique d'Iran entre 2006 et 2010. Dans cette étude transversale, 106 centres de chirurgie de la cataracte ont été sélectionnés dans toutes les provinces par échantillonnage aléatoire en grappes à plusieurs degrés. Le nombre de centres dans chaque province a été déterminé sur la base du nombre d'opérations de la cataracte et le nombre de dossiers de patients examinés dans chaque centre était proportionnel au nombre de chirurgies de la cataracte pratiquées dans ce centre. La prévalence des chirurgies de la cataracte est passée de 46% [IC à 95%, 35,3-56,8] en 2006 à 51,4% [IC à 95%, 40-62,7] en 2010 [p = 0,549]. Les patients sont restés plus d'une nuit à l'hôpital après 10,5% [IC à 95%, 6,9-14,1] des opérations. Le recours à la phaco-émulsification et l'anesthésie topique faisait augmenter la prévalence de la chirurgie ambulatoire et réduisait les complications intra-opératoires. Bien que la chirurgie de la cataracte en ambulatoire ait augmenté de 11,7%, l'utilisation de méthodes telles que la phaco-émusification n'est pas répandue, et davantage d'attention devrait être apportée aux obstacles qui s'opposent à la chirurgie de la cataracte en ambulatoire en République islamique d'Iran


Subject(s)
Noncommunicable Diseases , Cataract Extraction , Cross-Sectional Studies , Prevalence , Ambulatory Surgical Procedures
6.
Theriogenology ; 83(1): 78-85, 2015 Jan 01.
Article in English | MEDLINE | ID: mdl-25459033

ABSTRACT

Frozen-thawed rooster semen is not reliable for use in artificial insemination in commercial stocks. Low-density lipoprotein (LDL) has been assessed for effectiveness as a cryoprotectant in the extender to improve the quality of frozen-thawed rooster semen. Although LDL has been evaluated in a few studies in other species for semen cryopreservation, so far no study has been conducted to examine this cryoprotectant for cryopreservation of fowl semen. Thus, this study aims to analyze the effects of different concentrations of LDL (0%, 2%, 4%, 6%, and 8%) in a Beltsville extender for cryopreservation of rooster spermatozoa. In experiment 1, motion parameters, membrane integrity, acrosome integrity, apoptosis status, and mitochondria activity were assessed after freeze-thawing. The highest quality frozen-thawed semen was selected to be used for evaluation of the fertility rate in experiment 2. Semen was collected from six roosters, twice weekly, then extended in a Beltsville extender that contained different concentrations of LDL as follows: 0% (control), 1% (Beltsville plus 1% LDL [BLDL1]), 2% (BLDL2), 4% (BLDL4), 6% (BLDL6), and 8% (BLDL8). Supplementation of the Beltsville extender with 4% LDL produced the most significant percentage of motility (43.1 ± 1.3), membrane integrity (59.4 ± 2.1),mitochondria activity (49.1 ± 1.19), and viable spermatozoa (45 ± 2.28) compared with the control treatment with the results of 22.7 ± 1.3 (motility), 38.4 ± 2.1 (membrane integrity), 40.25 ± 1.19 (mitochondrial activity), and 37.8 ± 2.28 (viability). In experiment 2, a significantly higher percentage of fertility rate was observed for frozen-thawed semen in the extender supplemented with 4% LDL (49.5 ± 1.6) compared with the control (29.2 ± 2.9). Progressive motility and acrosome integrity were not affected by LDL levels in the extenders. The results revealed that supplementation of the Beltsville extender with 4% LDL resulted in higher quality of frozen-thawed rooster sperm.


Subject(s)
Chickens/physiology , Cryopreservation/veterinary , Fertility/physiology , Flow Cytometry/veterinary , Semen Preservation/veterinary , Semen/physiology , Animals , Cryoprotective Agents/pharmacology , Female , Lipoproteins, LDL/pharmacology , Male , Spermatozoa/physiology
7.
J Liposome Res ; 23(1): 61-9, 2013 Mar.
Article in English | MEDLINE | ID: mdl-23363305

ABSTRACT

Theranostic liposomes carry both the therapeutic active ingredients and the contrast agent into one delivery system. Codelivery of imaging contrast agent and chemotherapeutic drugs can provide real-time validation of the targeting strategy, resulting in an another step forward for individual-based therapy. The aim of this study was the incorporation of different drugs used in the diagnosis and treatment of tumors into one delivery system to develop nanosized, polyethylene glycol (PEG)-coated, different charged theranostic liposomes. Different charged liposomes consisting of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) or Phospholipon(®) 90G (PL 90G; Phospholipid GmbH, Cologne, Germany), cholesterol, poly(ethylene glycol)2000/phosphatidyl ethanolamine (PEG(2000)-PE), stearylamine (SA) or dicetyl phosphate (DCP), and diethylenetriamine pentaacetate/PE (DTPA-PE) as bilayer ingredients and 5-florouracil (5-FU) as active substance were prepared by the film technique. Characterization, 5-FU in vitro release, cytotoxicity, and physical stability studies were performed. Particle size of all liposomes was 100-150 nm. Difference was not noted between encapsulation efficiency (EE%) of neutral DPPC and PL 90G liposomes containing 5-FU. EE% of charged DPPC liposomes was higher than that of charged PL 90G liposomes. PL 90G containing liposomes had a higher phospholipid amount than the same formulation of DPPC liposomes. DPPC containing different charged liposomes were selected for cytotoxicity studies. Different charged DPPC liposomes had the same antitumoral activity with the free 5-FU solution on MCF-7 cell lines. Liposome dispersions were more stable from the point of particle-size change and 5-FU leakage during storage at refrigerated temperature. The results of this study are very encouraging for the development of theranostic liposome formulations as a targeted delivery system for drugs, such as 5-FU, used both in therapy and imaging.


Subject(s)
Diagnostic Imaging , Fluorouracil/administration & dosage , Liposomes/administration & dosage , Breast Neoplasms/drug therapy , Breast Neoplasms/pathology , Contrast Media/administration & dosage , Female , Humans , Liposomes/chemistry , Liposomes/therapeutic use , MCF-7 Cells , Particle Size , Pentetic Acid/administration & dosage , Pentetic Acid/chemistry
8.
Iran Red Crescent Med J ; 13(1): 21-6, 2011 Jan.
Article in English | MEDLINE | ID: mdl-22946015

ABSTRACT

BACKGROUND: Amblyopia is a relatively common condition in which visual acuity through an eye is subnormal despite no overt pathology. Pattern visual evoked potential (PVEP) can detect any defect from optic nerve to occipital cortex and pattern electroretinogram (PERG) can detect retinal defects specially the ganglion layers. This study was performed to evaluate the cortical and retinal activity in strabismic and anisometropic amblyopia. METHODS: PVEP and PERG were recorded simultaneously in 40 amblyopes (20 strabismics and 20 anisometropics) and 20 normal control subjects. Normal subjects were age and sex matched with patients. RESULTS: The P(100) latency in PVEP was increased in both groups of patients but the P(100) amplitude was reduced only in anisometropic group. In PERG, the amplitude of P(50) was reduced in all patients with no significant change in latency. CONCLUSION: Beside reduced PVEP responses in strabismic and anisometropic amblyopia, the activity of retina reduced too. It is likely that retinal impulses can affect the development of visual system.

10.
J Drug Target ; 16(1): 51-7, 2008 Jan.
Article in English | MEDLINE | ID: mdl-18172820

ABSTRACT

Recent research into the complex and varied components of rheumatoid arthritis (RA) is leading to the development of more effective targets for pharmaceutical approach than even before. Current treatment of RA frequently includes the use of nonsteroidal anti-inflammatory drugs, such as Diclofenac sodium (DFNa) in spite of the severe adverse effects. Local application and incorporation of the drugs in liposome based formulations may reduce those side effects and improve the efficacy of drugs by reducing the availability of them in systemic circulation and increasing accumulation and retention time in the sites of inflammation. Herein, anti-inflammatory efficacy of the DFNa containing lipogelosome formulations (L1J1) was evaluated and found that L1J1 elicits a better anti-inflammatory efficacy after a single dose i.a. administration in comparison with commercial product, VE-CP, which is used topically. Histopathological examination of the opened joints showed that joints treated with L1J1, had significantly (p < 0.05) lower scores than contra lateral control joints for inflammatory changes in the synovium. These results were also confirmed by biodistribution studies.


Subject(s)
Anti-Inflammatory Agents, Non-Steroidal/administration & dosage , Anti-Inflammatory Agents, Non-Steroidal/therapeutic use , Arthritis, Rheumatoid/drug therapy , Diclofenac/administration & dosage , Diclofenac/therapeutic use , Animals , Anti-Inflammatory Agents, Non-Steroidal/pharmacokinetics , Arthritis, Rheumatoid/metabolism , Arthritis, Rheumatoid/pathology , Chemistry, Pharmaceutical , Diclofenac/pharmacokinetics , Drug Carriers , Excipients , Gels , Injections, Intra-Articular , Joints/pathology , Liposomes , Rabbits , Tissue Distribution
11.
Brain Behav Evol ; 55(3): 152-62, 2000 Mar.
Article in English | MEDLINE | ID: mdl-10899709

ABSTRACT

Weakly electric fish emit an electric communication signal that is controlled by a highly specialized neural circuit. In Apteronotus, the continuous electric organ discharge (EOD) is generated by electrotonically coupled neurons in the hindbrain pacemaker nucleus, and transient EOD modulations involve chemical synapses from descending midbrain and thalamic prepacemaker nuclei. We characterized the effects of temperature change (18-32 degrees C) on both the continuous EOD and EOD modulations, chirps, in A. leptorhynchus. EOD frequency was linearly related to temperature (Q(10)=1.62). By contrast, the temperature dependence of EOD amplitude changed with temperature. Amplitude increased steeply with temperature below 25 degrees C (Q(10)=2.0), but increased only gradually above 25 degrees C (Q(10)=1.15). EOD waveform, and consequently harmonic content, was also affected by temperature. The amplitude of the second harmonic was relatively high at both low and high temperature and relatively low at intermediate temperatures. The amplitude of the third harmonic increased monotonically with temperature. Thus, temperature has qualitative as well as quantitative effects on the production of the EOD. Chirp rate (Q(1)0=3.2) had a higher temperature dependence than that of the continuous EOD, which likely reflects its reliance on chemical rather than electrotonic synapses. In vitro pacemaker firing frequency had a similar, but slightly higher Q(10) (1.82) than that of the EOD frequency.


Subject(s)
Animal Communication , Body Temperature/physiology , Brain/physiology , Electric Fish/physiology , Neurons/physiology , Periodicity , Animals , Female , Male
12.
Anal Chem ; 72(8): 1894-904, 2000 Apr 15.
Article in English | MEDLINE | ID: mdl-10784159

ABSTRACT

We examine the use of thionylphosphazene-based block copolymers as matrixes for oxygen sensor applications. Poly(aminothionylphosphazene)-b-poly(tetrahydrofuran) (PATPy-PTHFx) block copolymers were prepared via reaction of ring-opened poly(chlorothionylphosphazene) with THF and subsequently with excess n-butylamine (to form PBATPy-PTHFx) or methylamine (to form PMATPy-PTHFx). The block copolymers were characterized by NMR, gel permeation chromatography, and differential scanning calorimetry. Films of PBATPy-PTHFx block copolymers containing platinum octaethylporphyrin or [Ru(dpp)3]Cl2 (dpp = 4,7-diphenyl-1,10-phenanthroline) as the oxygen-sensitive chromophore were prepared, and time-scan experiments were carried out to determine the diffusion coefficients, Do2, and solubilities, So2, of oxygen therein. Despite microphase separation, the data fit well to a simple Fick's law description of oxygen diffusion and gave Do2 values smaller than that for the n-butylamino-substituted PBATP635. For films freshly annealed above the melting point of PTHFx, the Do2 values were 35-50% (dye-dependent) larger than after aging 3 days at room temperature. Films with [Ru(dpp)3]Cl2 as the dye were evaluated as media for phosphorescent pressure-sensing. The dye-containing polymer films exhibit linear Stern-Volmer-like plots, even at high dye concentrations, as well as good photostability, and significantly higher sensitivity to oxygen quenching than simple mixtures of the analogous homopolymers.

13.
Optom Vis Sci ; 66(12): 815-7, 1989 Dec.
Article in English | MEDLINE | ID: mdl-2626245

ABSTRACT

The use of changes in fixation disparity, the associated phoria, and the dissociated phoria in assessing the degree of visual stress requires that we know the effect of vision under close working conditions (40 cm) on these parameters. The authors have previously reported that reading under the stress of abnormally low illumination, or at too close a working distance (20 cm), increases fixation disparity and associated phoria and is associated with symptoms and visual discomfort. The current study shows that reading at photopic levels of illumination and at a working distance of 40 cm does not change the magnitudes of fixation disparity and associated phoria. Reading under these conditions is not accompanied by an onset of symptoms or visual discomfort. This result indicates that changes in fixation disparity and associated phoria are a product of visual stress and are not produced by reading itself.


Subject(s)
Fixation, Ocular/physiology , Stress, Physiological , Vision Disparity/physiology , Vision, Binocular/physiology , Adolescent , Adult , Humans , Lighting , Reading , Strabismus/etiology , Vision Tests
14.
Ophthalmic Physiol Opt ; 9(2): 115-20, 1989 Apr.
Article in English | MEDLINE | ID: mdl-2622645

ABSTRACT

Changes with age in heterophoria, associated heterophoria, fixation disparity and stereopsis for near vision were investigated in a sample of 187 subjects (age range from 10 to 65 years) divided into six age groups. With increasing age, heterophoria, associated heterophoria and fixation disparity increased in the exo-direction. No change in stereopsis was found. A comparison with visual symptoms for near vision indicated a relationship between symptoms and the magnitude of fixation disparity and associated heterophoria for all age groups, but no relationship was found between the presence of symptoms and heterophoria measurement. No relationship between the presence of symptoms and the central slope of the forced vergence fixation disparity curve was found. These findings suggested that neither the measurement of heterophoria nor the forced vergence disparity curve are appropriate tests in the assessment of binocular vision anomalies. However, fixation disparity and associated heterophoria are related to binocular problems for near vision in all age groups.


Subject(s)
Aging/physiology , Vision Disorders/physiopathology , Vision, Binocular , Adolescent , Adult , Aged , Child , Depth Perception , Fixation, Ocular , Humans , Middle Aged , Presbyopia/physiopathology , Vision Disparity , Vision Tests
15.
Ophthalmic Physiol Opt ; 9(2): 121-5, 1989 Apr.
Article in English | MEDLINE | ID: mdl-2622646

ABSTRACT

Two groups of patients, one under 40 years of age and the other 40 years and over, were divided into subgroups according to whether they had symptoms associated with near vision. A method developed in 'signal detection theory' was used to determine whether a value could be found for heterophoria, or associated heterophoria, which would predict which patients had symptoms due to decompensated heterophoria in normal routine investigation. Receiver operator characteristic curves (ROC curves) were constructed to look for these cut-off values between patients with, and without, symptoms. No value for dissociated heterophoria was found that would discriminate between the symptomatic and asymptomatic patients. It is concluded that heterophoria measurement is not useful as a routine procedure. In the case of associated heterophoria, for the under 40 years age group, patients with a value of 1 prism dioptre or more are more likely to have symptoms than not, and one-third of patients with close work problems have a value of 2 prism dioptres or more. It was rare to find any asymptomatic patient with a value as high as this. In the 40 years and over age group those with an associated heterophoria of 2 prism dioptres or more are more likely to have symptoms than not. One-third of patients in the latter age group, with symptoms, have a value of 3 prism dioptres or more whilst it is rare to find an asymptomatic patient with a value as large as this.


Subject(s)
Vision Disorders/physiopathology , Vision, Binocular , Adult , Aged , Contrast Sensitivity , Fixation, Ocular , Humans , Middle Aged , Optics and Photonics , Pilot Projects , Predictive Value of Tests , Presbyopia/diagnosis , Presbyopia/physiopathology , Vision Disorders/diagnosis , Vision Tests
16.
Am J Optom Physiol Opt ; 64(7): 513-8, 1987 Jul.
Article in English | MEDLINE | ID: mdl-3631207

ABSTRACT

Fixation disparity has been shown to be produced by prism stress, and it has therefore been proposed that its presence constitutes a sign that binocular vision is under stress (decompensated heterophoria). Fixation disparity can be present in the absence of any other indication of stress, and therefore may have a physiological basis. This study investigates the effect on fixation disparity and visual discomfort of placing the visual system under a different type of stress, that of requiring the subject to read under conditions of inadequate illumination. In 50 young adults, it was found that fixation disparity increased under inadequate illumination and that this was accompanied by symptoms in the form of visual discomfort. After a period of rest from any near-vision task, the fixation disparity decreased and the symptoms were reduced.


Subject(s)
Fixation, Ocular , Lighting , Reading , Adolescent , Adult , Child , Humans , Middle Aged , Strabismus/etiology , Strabismus/physiopathology
17.
Ophthalmic Physiol Opt ; 7(4): 345-7, 1987.
Article in English | MEDLINE | ID: mdl-3454908

ABSTRACT

It is well established that prism stress on binocular vision produces fixation disparity. It is therefore suggested that fixation disparity is a sign of stress on binocular vision. The authors have previously looked at the stress caused by reading in reduced levels of illumination, and found that the average fixation disparity and associated heterophoria become more exophoric. In this paper the effect on fixation disparity and associated heterophoria of reading at an abnormally close distance is reported. It was found that in 50 young adults fixation disparity and associated heterophoria increased to a greater degree of exo-disparity. An analysis of the visual symptoms indicated that there was also an increase in the visual discomfort and other symptoms.


Subject(s)
Fixation, Ocular , Reading , Vision Disorders/physiopathology , Adult , Depth Perception/physiology , Humans , Lighting , Stress, Physiological/physiopathology
18.
Ophthalmic Physiol Opt ; 7(4): 349-52, 1987.
Article in English | MEDLINE | ID: mdl-3454909

ABSTRACT

This paper looks at the clinical investigative and measurement procedures used in assessing binocular vision at the beginning of a normal working day and compared with the same procedures carried out in the afternoon which included several hours of close work. In 84 young adults, it was found that dissociated heterophoria, associated heterophoria and fixation disparity increased. This was accompanied by visual symptoms. It is likely that any decompensation of heterophoria is worse at the end of a working day. The results of this investigation raise the question of the value of some clinical tests for binocular assessment carried out at the beginning of the day.


Subject(s)
Depth Perception/physiology , Vision Disorders/physiopathology , Adolescent , Adult , Fixation, Ocular , Humans , Middle Aged , Reading , Stress, Physiological/physiopathology , Time Factors , Vision Disorders/etiology
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