[Comparative study of the effect of pilocarpine and tropicamide eye drops on corneal topography]

This study was conducted to evaluate the effect of contraction and relaxation of ciliary muscle caused by pilocarpine and tropicamide eye drops on corneal radius, central corneal power and corneal astigmatism. This prospective study was performed on sixty normal and healthy eyes of sixty volunteers with a mean age of 38.19 year [range 18 to 49 years] and without any ocular pathology. Volunteers divided into 2 groups of thirty, in the first group corneal topography of both eye were measured before and 30 minutes after instillation of topical tropicamide 0.5% in only one eye, and the other eye was the control eye and no drop was given. In the second group, the same routine was performed, except that subject received on drop of pilocarpine 1% in one eye. Statistical comparison between groups for the central corneal power, corneal radius and corneal astigmatism were performed using paired t test. In group 1, no significant changes were found in corneal radius, power and astigmatism, however, in group 2 subjects who have received pilocarpine eye drop, mean corneal radius value decreased significantly by 0.05 mm and mean corneal power increased by a plus power of + 0.32 D. There was no significant change in corneal astigmatism in both groups. It seems that pilocarpine induced ciliary muscle contraction which may cause pressure on corneal limbus of cornea and scleral spur that resulted in changes in corneal curvature. But tropicamide eye drop did not affect corneal radius and other corneal parameters and corneal topography can be carried out after instillation of tropicamide eye drop

[Evaluation of pattern reversal visual evoked potential components in albinism]

Albinism is a genetic disorder that affects melanin synthesis of the human being. Although not very common, it has serious effects on the visual system, particularly reduced visual acuity. The pattern visual evoked potential is a reliable objective technique for diagnosing the latent and misrouting of this condition. The aim of this study was to use and evaluate the importance and accuracy of a single channel PVEP instead of common multichannel PVEP for detecting asymmetric responses between the latent and misrouting albinism and control group. In this cross sectional study, the pattern visual evoked potentials were measured using 60 min/arc check sizes with temporal frequency of 3 Hz in twenty four suspected albino people ages of 5 to 43 years [mean age of 19 years]. Amplitude and latencies time were measured for both the right and left, and then the results were compared with an age- and gender matched, normal group. The latency waves of N75, P100, N135 and P1N1 [N75-P100] amplitude between two eyes of the albino people showed a statistically significant difference. The asymmetric responses of PVEP between two of the albino people were significantly larger than than control group. There is a strong relation between asymmetric responses of single channel PVEP and other clinical signs of albinism, which make this method as a useful objective technique for diagnosing the latent albinism

[Effect of induced refractive errors on measurement of color vision by using D15 test]

To evaluate the effect of Hyperopia, Myopia and Astigmatism on measurement of color vision, we experimentally induced refractive errors by positive, negative and cylinder lenses and estimated this effect on measurement of color vision. From one hundred patients referred to optometry clinic, sixty subjects with distance corrected or uncorrected visual acuity of 6.6, and without any ocular pathology were selected. Color vision was measured by D15 test before and after introducing 2 to 14 diopter positive lenses, 4 to18 diopter minus lenses and 2 to 10 diopter positive cylinder lenses, to induce Hyperopia, myopia and astigmatism respectively. The age was between 15 to 45 years. Although the decrease in color vision [or increase in the mean errors] was significant by introducing 4 to 14 positive, 8 to 18 minus and 4 to 10 cylinder, but it was not statistically significant by introducing 3 D positive lenses, 3D cylinder lenses and 4 D minus lenses. Induced 4 D or more myopia and astigmatism reduces color vision measured by D-15 test. But induced 8D or more Hyperopia can cause reduction in color vision measurement? On the other hand myopia and astigmatism less than 4 diopters, and hyperopia less than 8 diopters have no effect on the measurement of color vision

[Evaluation of depth perception and heterophoria among laboratory sciences students in Mashhad, 2011]

Normal stereopsis as the highest level of binocular vision is required for most of clinical works such as working with microscope and some jobs, like piloting and surgery. The aim of this study was to evaluate, depth perception and hetrophoria in Mashhad laboratory sciences students in 2011. In this cross sectional study from 153 Mashhad laboratory sciences students, 42 subjects were selected randomly. Eye examinations including subjective and objective refraction and measurement of hetrophoria by cover test and prism bar were performed. The stereopsis was then determined with the T.N.O stereo test at 40 distance observation. Data were analyzed using SPSS version 11.5 software. Patients with amblyopia, cataract, and other ocular pathology were excluded from the study. Mean stereoacuity of the subjects was 147/14 +/- 129/76. Among this population, 14 subjects [%33.3] used microscope monocularly and 28 subjects [% 66.7] used it bionocularly. There was no significant difference between mean stereopsis and hetrophoria and other relative effective factors such as refractive error, way of using microscope, near point of convergence age and sex [p>0.05]. Comparison between mean monocular and binocular stereopsis was not significant [p>0.05]. There was no statictically significant difference between mean stereopsis and hetrophoria and other relative factors. However due to working too much with microscope, most of the laboratory sciences students had anomaly of binocular vision like intermittent exotropia and abnormal near point of convergence. This indicates the necessity of more research in anomaly of binocular vision in laboratory sciences students

[Evaluation of the effect of daily work and resultant tiredness on near steroacuity in intermittent exotropic patients]

Variations in sterioacuity may be used in an assessment of intermittent exotropia. Intermittent exotropia is divergent squint of eyes that is worsened due to daily visual tasks and its resultant tiredness therefore the amount of deviation increases. The purpose of this study is to determine the effect of daily work and resultant tiredness on near sterioacuity among intermittent exotropic patients. In this cross-sectional study, 600 dormitory students of Mashad University of Medical Sciences, ranging in age from 21 to 23 years, examined with alternate cover test to diagnose intermittent exotropic cases. 30 students had intermittent exotropia and along with 15 normal cases constituted the case-control group. Sterioacuity was measured twice, in the morning and at night, with Randot-SO 001 test. Suppression was checked with Bagoloni striate lens and 4 prism diopter base out test. Data were statistically analyzed with SPSS software [version 13]. The measured deviation in intermittent exotropic cases showed a significant difference between the deviation in the morning and late at night among 23.33% [7 cases] [P=0.00]. In addition, sterioacuity decreased significantly at night, [P=0.00] among these cases. Despite the increase in the deviation among 53.3% [16 cases] at night, steriacuity was not changed significantly. 23.33% [7 cases] did not show any changes in the morning and at night, both in deviation amount and sterioacuity measurement. In most intermittent exotropic cases, there is no significant correlation between intermittent exotropia and near sterioacuity variations after daily work and resultant tiredness [P<0.696]

[ prevalence of congenital color blindness and its effect on contrast sensitivity and depth perception]

Color blindness is a common disorder. The congenital type of tcolor blindness is sex-linked and the genes are located on the X chromosome. The prevalence of color blindness among males and females are 5-8% and 0.5%, respectively. Color blindness may affect daily activities and could be considered as a disability. Therefore, the aim of this study was to investigate the prevalence of color blindness and its effect on contrast sensitivity and depth perception among school children in Mashhad. Four thousand four hundred school children [2408 males and 1992 females] were selected randomly and tested by Ishihara for color blindness detection. At the second step, students with color blindness were examined at optometry clinic by the Ishihara test again. Two hundred students were also selected randomly to allocate into a control group. Cambridge and Titmouse tests were taken on the case and control groups. Among 4400 schoolchildren, 3% suffered from color blindness [5.1% in boys and 0.4% in girls]. Ishihara test showed 2.2% deuteranopia, 0.8% protanopia and 0.6% suspect. The results indicate that the congenital color blindness has no significant effect on contrast sensitivity and depth perception. The present report provides valuable information regarding color vision defectiveness among schoolchildren. Effective detection of this anomaly is expected to prevent from substantial effects on their education and future job. It is strongly recommended to perform color vision test at the beginning of a child's education

[Relationship between central corneal thickness, intra ocular pressure and visual field in normal tension and primary open angle glaucoma]

Glaucoma is one of the most important cause of blindness wordwide. Exact determination of intra ocular pressure is important for the diagnosis and decision making about glaucoma treatment. Central corneal thickness is considered as effective factor on intra ocular pressure and visual field defect. This study was carried out to determine the relationship between central corneal thickness, intra ocular pressure and visual field in normal tension and primary open angle glaucoma. This descriptive study was carried out on 45 eyes with normal tension glaucoma and 45 eyes with primary open angle glaucoma in Al-Zahra ophthalmology hospital in Zahedan, Iran during 2010. Intra ocular pressure and central corneal thickness were measured by Goldman tonometer and pachymeter and visual field exanimated by Humphrey perimeter. Data were analyzed using SPSS-16, paired t-test, ANOVA, Mann-Whitney and Pearson correlation tests. There was significant correlation between central corneal thickness and intra ocular pressure [r=0.309, P<0.05]. A significant difference was detected in intra ocular pressure between two type of glaucoma [P<0.05]. Mean value of central corneal thickness in patient with mild visual field defect was higher than severe visual field defect but there was not significant statistical difference between central corneal thickness and visual field defect in subjects with glaucoma. This study indicated that increasing corneal thickness is accompanied with intra occular presure

[ prevalence of refractive errors in a Mashhad, Iran]

To determine the prevalence rates of refractive errors in Mashhad, Iran. In this population-based study, random cluster sampling was performed on the urban population of Mashhad and of 4453 selected individuals, 70.4% participated in the study. Refractive errors were assessed using cycloplegic refraction in participants who were 15 years of age. The prevalence of myopia and hyperopia in individuals 15 years of age was 22.36% [95% CI: 24.66 to 20.06] and 34.21% [95 CI: 36.85 to 31.57], respectively. The prevalence of astigmatism and anisometropia were 25.64% and 5.84, respectively. Astigmatism and anisometropia were significantly more [p=0.005] and less [p=0.048] prevalent in females, respectively. Anisometropia, astigmatism and hyperopia were found to be increased with age. This study highlighted the valuable information on refractive errors in Mashhad. Hyperopia was the most common refractive error. In addition to subjects who were between 5 to 15 years of age, refractive errors were also prevalent among older people; therefore, more attention should be paid to the correction of refractive errors in these groups

Simultaneous pattern visual evoked potential and pattern electroretinogram in strabismic and anisometropic amblyopia

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. 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. The P100 latency in PVEP was increased in both groups of patients but the P100 amplitude was reduced only in anisometropic group. In PERG, the amplitude of P50 was reduced in all patients with no significant change in latency. 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

Procedures of starting up and implementing of subsurface wetlands

Background and Purpose: Subsurface flow wetlands are one of the successful treatment methods used for municipal and industrial wastewater treatment, and are economical in terms of energy consumption and workforce. Much research has been conducted on wetland operation output in wastewater treatment, but no enough information is available on their start-up and maintenance. The present study investigates the circumstance of starting up and implementing a wetland

Methods and Materials: In this experimental study, two subsurface flow wetlands with a two-day detention time and two pretreatment units were built. The former was similar to Primary Settling tank with a 4-hour detention time and the latter was similar to anaerobic pond equipped a with digestion pit with a two-day detention time in a pilot scale. The wastewater [BoD5 = 250 mg/l, Tss=320 mg.l and ph=7.2] from municipal network in Sabzevar, Iran was used for irrigation; the pilot implementation and maintenance took one year

Results: Pilot operation indicated that the principal factors in implementing subsurface flow wetland were temperature, nonpenetrateability of the bed, and wastewater ingredients. However, pretreatment and bed obstruction were the limiting parameters of the wetland maintenance

Conclusion: Pretreatment of the subsurface flow of wetlands does not yield a high output; and if anaerobic ponds equipped with digestion pits are used, the treatment output is significantly enhanced, and the wetland operation will face minimum barriers

Removal of triethylamine vapor from waste gases by biotrickling filter

Sampling of triethylamine in the cold-box unit in an auto-manufacturing company in Iran has indicated the average concentration of 430 mg/m[3] in the emission duct. In this study a biotrickling filter was used for treatment of triethylamine in air stream. Triethylamine removal efficiency [K/L] pattern was evaluated by changing volumetric loading [L], superficial gas velocity [U[o]], empty bed gas retention time [EBRT] and recirculation liquid flow rate [V[L]], while operating at constant temperature of 25 +/- 1 Degree C. For finding the effect of EBRT on the triethylamine removal efficiency, tests were performed at EBRT of 156 s, 52s and 31s and a constant liquid recirculation velocity of 3.466 m[3]/m[2]/h. Results showded that for a test period of 65 days, triethylamine removal efficiencies of more than 98% were obtained for EBRT of 156s and loading rates of less than 48 g/m[3]/h. With an EBRT of 52s removal efficiencies of > 90% were obtained for loadings of < 57 g/m[3]/h and maximum removal capacity was 53.4 g/m[3]/h at volumetric loading of 64 g/m[3]/h. Also with an EBRT of 31 s the maximum removal capacity was 53.6 g/m[3]/h at volumetric loading of 68 g/m[3]/h. Thus in the range of implemented EBRTs the proper absorption of triethylamine from gas to liquid phase took place and the elimination efficiency was shown to be dependent on microorganisms activity rate. The effect of liquid flow rate on the triethylamine removal efficiency was investigated by changing VL in the range of 3.46 to 10.40 m[3]/m[2]/h at EBRT=31 s and influent triethylamine concentration of 600 mg/m[3]. Results showed that the triethylamine removal efficiency was nearly independent of the liquid recirculation rate

[ prevalence of visual problems in school children, Shiraz, Iran]

Refractive errors [myopia, hyperopia and astigmatism] could lead to an impaired quality of life affect a large proportion of the population worldwide, irrespective of age, sex and ethnic group. Such refractive errors can be easily diagnosed, measured and corrected with spectacles or other refractive corrections to attain normal vision. Since there is paucity of information in school children in Iran we aimed to investigate the distribution pattern of refractive status and prevalence of refractive errors in school-age children in Shiraz. A random sampling strategy in geographically defined clusters was used to identify children aged 6-15 years in Shiraz between 2008-2209. We carried out a school survey and actual eye examinations, including visual acuity measurements, stereopsis examination, anterior segment and eyeball movements, fundus examinations, and cycloplegic retinoscopy with 1% cyclopentolate. Of 3065 selected individuals, 2683 were participated in the study [response rate 86.6%]. According to cycloplegic refraction, 4.85% [95% [CI], 3.52 to 6.16] of the primary and middle school students were myopic and 4.64% [95% CI, 3.52 to 6.19] were hyperopic. For high school students, these rates were 22.19 and 11.4% respectively. Myopia and hyperopia were shown to be correlated with age. Prevalence of anisometropia, amblyopia and strabismus were 2.51%, 2.31[95%CI 1.51-3.11] and 1.83% [95%CI 1.15-2.50]. Compared to other published reports, the rate of myopia in the school children of Shiraz seems relatively high

Kinetic analysis of enhanced biological phosphorus removal in a hybrid integrated fixed film activated sludge process

Hybrid integrated fixed film activated sludge is a promising process for the enhancement of nitrification, denitrification and phosphorus removal in conventional activated sludge systems that can be used for upgrading biological nutrient removal, particularly when they have space limitations or need modifications that will require large monetary expenses. In this research, successful implementation of hybrid integrated fixed film activated sludge process at temperate zone wastewater treatment facilities has been studied by the placement of fixed film media into aerobic, anaerobic and anoxic zones. The primary objective of this study was to investigate the incorporation of enhanced biological phosphorus removal into hybrid integrated fixed film activated sludge systems and study the interactions between the fixed biomass and the mixed liquor suspended solids with respect to substrate competition and nutrient removal efficiencies. A pilot-scale anaerobic-anoxic-oxic configuration system was used. The system was operated at different mean cell residence times and influent chemical oxygen demand/total phosphorus ratios and with split influent flows. The experimental results confirmed that enhanced biological phosphorus removal could be incorporated successfully into hybrid integrated fixed film activated sludge system, but the redistribution of biomass resulting from the integration of fixed film media and the competition of organic substrate between enhanced biological phosphorus removal and denitrification would affect performances. Also, kinetic analysis of the reactor with regarding to phosphorus removal has been studied with different kinetic models and consequently the modified Stover-Kincannon kinetic model has been chosen for modeling studies and experimental data analysis of the hybrid integrated fixed film activated sludge reactor

Investigation of intermittent chlorination system in biological excess sludge reduction by sequencing batch reactors

The excessive biological sludge production is one of the disadvantages of aerobic wastewater treatment processes such as sequencing batch reactors. To solve the problem of excess sludge production, oxidizing some of the sludge by chlorine, thus reducing the biomass coefficient as well as the sewage sludge disposal may be a suitable idea. In this study, two sequencing batch reactors, each with 20 L volume and controlled by on-line system were used. After providing the steady state conditions in the reactors, sampling and testing of parameters were done during 8 months. The results showed that during the solid retention time of 10 days the kinetic coefficient of Y and Kd were 0.58 mg biomass/mg COD and 0.058/day, respectively. At the next stage, different concentrations of chlorine were used in the reactors intermittently. Results showed that 15 mg chlorine/gMLSS in the reactor was able to reduce the yield coefficient from 0.58 to 0.3 mg biomass/mg COD. In other words, the biological excess sludge was reduced about 48%. But the soluble chemical oxygen demand increased slightly in the effluent and the removal percentage decreased from 95% in the blank reactor to 55% in the test reactor

Visual function following treatment of optic neuritis

Optic neuritis is a common cause of visual loss in young adults and often the first manifestation of multiple sclerosis. Recent studies have shown that treatment with intravenous methylprednisolone results in more rapid recovery of vision, but without any long term difference in visual acuity. This study was carried out to evaluate clinical characteristics of patients with optic neuritis and visual outcome after intravenous methylprednisolone treatment. In a case series study, 40 cases with optic neuritis were evaluated. Before and after treatment with methylprednisolone according to optic neuritis treatment trial, visual acuity, contrast sensitivity, color vision, streopsis and visual field were analyzed. 67.5% of the patients were females. The most common age group was between 20 and 40 [60%]. Blind spot enlargement and other visual field defects were also returned to relatively normal value after the treatment. Central scotoma was the most common field defect [70%] and mild Dutan defect was the most common color vision [60%] defect in this study. Visual acuity, contrast sensitivity, color vision, streopsis and visual field were significantly reduced in optic neuritis, relatively returning to the normal level after treatment. It seems that the assessment of other visual functions, besides visual acuity, is important in a patient with optic neuritis, because patients usually remain aware of visual deficits other than decreased visual acuity

Evaluation of upper limb disability in pregnant women suffering from carpal tunnel syndrome

Carpal tunnel syndrome [CTS] is a collection of sensory-motor signs and symptoms which are created due to mechanical pressure on median nerve at wrist. A considerable portion of these patients are pregnant women. The aim of this study was evaluate functional disabilities of upper limb due to CTS in pregnant women. A descriptive and analytical study was performed on 267 pregnant women, who had received health care service in Obstetrics and Gynecology clinics of Shariati and Sepahan hospitals in Isfahan Iran, 2005. From the total number of the pregnant women, 52 women who were affected by carpal tunnel syndrome [CTS] and 54 women who had not shown the symptoms of CTS were divided in two different groups. Minor and background data were obtained from conversation and physical examination. Scores of functional disability of upper limb were obtained from DASH questionnaire. Student's t test and Man-Whitney test were used to compare the difference between groups. 52 out of 267 pregnant women [19.47%] suffered from carpal tunnel syndrome [CTS] with average age of 25 +/- 4.3 years. 51.9% of the women were experiencing their first pregnancy [primigravida]. 82.7% of the pregnant women affected carpal tunnel syndrome [CTS] in third trimester of their pregnancy. The average weight gain in affected carpal tunnel syndrome women was significantly more than the asymptomatic women [P < 0.001]. The total score and mean score of other parts of DASH scoring system in affected carpal tunnel syndrome women were significantly higher than the asymptomatic women [P < 0.001]. Carpal tunnel syndrome [CTS] in pregnant women, especially during third trimester, can lead to functional disabilities in their upper limb. As a result, it can cause undesirable effects on personal efficiency. So, it is needed to teach and give more information to the pregnant women about these disabilities

Effect of glucose - insulin - potassium [GIK] solution on short term prognosis of unstable angina

Unstable angina as a clinical condition includes a major group of patients manifested with acute coronary syndrome. Misdiagnosis of this clinical syndrome causes myocardial infarction [MI] and death. Conventional and advanced forms of treatment are used with the aim of rapid stabilization of unstable angina. Although infusion of glucose - insulin - potassium [GIK] solution has had good results in acute MI, no major trial has studied its effect in unstable angina. The main goal of this study was evaluation of the effectiveness of GIK solution on prognosis of hospitalized unstable angina patients. This randomized clinical trial included patients with class II and III unstable angina [two groups of 94 patients, each] with a mean age of 62.47 +/- 13.20 years and Female /Male ratio of 1.35 admitted in the CCU's of Yazd from September 2003 to May 2004. There was no significant difference between the study and control groups regarding mean age, sex ratio and unstable angina class [P = 0.15, P = 0.77 and P = 0.76]. The study group had significant reduction in recurrent chest pain and duration of hospitalization [P = 0.001 and P = 0.02]. The most common adverse effect ofGIK solution was pain at infusion site. Use of GIK solution causes early stabilization of unstable angina patients without any significant or life threatening adverse effect

Seroprevalence of toxocariasis in children aged 1-9 years in western Islamic Republic of Iran, 2003

We determined the seroprevalence of Toxocara canis infection in 544 children under 10 years randomly selected from urban and rural areas of Hamadan. An enzyme-linked immunosorbent assay was used for detection of antibodies to T. canis excretion-secretion antigens. Using a questionnaire, epidemiological factors associated with infection were examined, including age, sex, residence. Antibodies to T. canis were detected in 29 children [5.3%] and 19 children [3.5%] were categorized as borderline positive; thus together this gave a prevalence of toxocariasis of 8.8%. No significant differences were found in terms of sex, age and residence.

Cadmium absorption and accumulation in different parts of kidney beans, radishes and pumpkins

This study is done to measure the absorption and distribution of cadmium in different parts of kidney beans, radishes and pumpkins. Three parts of a field was chosen. In one part 65 ppm of cadmium nitrate was added to water and in the other part 130 ppm, the last part was irrigated with normal water. Samples were digested by EPA 3050 method. Cadmium concentration was measured by Unicam 919 absorption unit. Beans accumulate cadmium mostly in root [70 ppm] and a little amount is mobilized through upper parts [12-16ppm], but kidneys did not accumulate a significant amount. In radishes the roots did not accumulate a significant amount of cadmium but stems had 4 ppm and leaves had 25 ppm. Cadmium concentration in soil does not affect its concentration in different parts of pumpkins and beside the stems and leaves [4 ppm] the other parts' concentrations were insignificant. In regard to the results of this study the cadmium concentrations in edible parts of the samples [kidney beans, radish roots and pumpkin fruit] were less than the U.S. EPA standards for agriculture and human beings