monireh mahjoob

Ophthalmology education within medical curricula plays a vital role in shaping students' knowledge and practical skills related to ocular diseases. This study aimed to assess the knowledge of medical interns at Zahedan University of Medical Sciences concerning eye examinations and ocular diseases in 2023.

This descriptive-analytical study was conducted on 96 medical interns at Zahedan University of Medical Sciences in 2023. A researcher-developed questionnaire, comprising 10 questions related to eye examinations and ocular diseases, was employed. The instrument's validity and reliability were established with a content validity index of 90%, a content validity ratio of 60%, and a Cronbach's alpha of 0.72. Data analysis was performed using SPSS version 24, employing descriptive statistics (mean, standard deviation, and frequency percentage) and inferential statistics, including the chi-square test.

The mean scores for the ophthalmology section were 16.93 ± 1.68 for male interns and 16.90 ± 1.94 for female interns. Overall, 7.3% of the students demonstrated good knowledge, 43.8% average knowledge, and 49% poor knowledge. No statistically significant difference was found between knowledge level and either ophthalmology section score (p = 0.957) or gender (p = 0.806).

The results of this study indicate that medical interns demonstrated a low level of knowledge regarding ocular diseases. This knowledge deficit should be considered a significant concern by administrators, necessitating a review and revision of ophthalmology education for medical students.

To investigate the effect of the near visual task of movie-watching in the straight gaze position on corneal topographic parameters.

Thirty myopic young adults with an average age of 25.10 ± 4.13 years were recruited for the study. The designed near visual task consisted of watching a movie in the straight gaze position at a distance of 40 cm for 30 minutes. Corneal topography was performed using Oculus Keratograph 4 (OCULUS, Wetzlar, Germany) before and immediately after watching the movie, as well as at 10, 20, and 30 minutes intervals after completing this near visual task. Zernike coefficients, asphericity indices, refractive parameters, and diagnostic indices of keratoconus were recorded for statistical analysis.

Movie-watching at a close distance solely using the straight gaze position had no effect on Zernike coefficients (P > 0.130). Also, watching the movie had no effect on other corneal topography parameters including irregularities (P = 0.208), spherical eccentricity (P = 0.270), maximum decentration (P = 0.553), axis of maximum decentration (P = 0.186), peripheral astigmatism (P = 0.179), and average asphericity of the quadrants at 10 to 30º (P > 0.163).

The results of the present study showed that watching movies in the straight gaze position had no effect on corneal topographic parameters and did not cause errors in corneal topographic measurements.

 The study aims to determine the age- and sex-adjusted prevalence of refractive errors and its related factors among the adult population of southeastern Iran.

 The current study included 9280 individuals aged 35 to 70 years using a multistage random sample method from October 2015 to January 2019 as a part of a Persian cohort study in Zahedan. Uncorrected and corrected vision, objective noncycloplegic, and subjective refraction were measured, with all participants undergoing ophthalmoscopy, slit-lamp biomicroscopy, fundoscopy, refraction, and retinoscopy. Data were analyzed using SPSS version 23.0 statistic software and described as percentage, odds ratio, and 95% confidence interval. Comparisons between groups and relationships among risk factors and refractive errors were performed with chi-square, nominal, and multiple regression analysis.

 The prevalence of low and moderate myopia, high myopia, low and moderate hyperopia, high hyperopia, low and moderate astigmatism, and high astigmatism was 24.2 (95% CI: 22.40 - 25.90), 1.5(95% CI: 0.00 - 3.53), 16.1(95% CI: 14.20 - 17.90), 1.3(95% CI: 0.00 - 3.30), 35.6 (95% CI: 33.90 - 37.30), and 3.8 (95% CI: 1.80 - 5.70) percent, respectively. The prevalence of refractive errors significantly varied across different age groups overall and by sex (P = 0.01). The proportion of refractive errors also significantly differed by education (P = < 0.001). The prevalence of against the rule, with the rule, and oblique astigmatism was 32.8 % (95% CI: 31.10 - 34.20), 42.1% (40.50 - 43.60), and 24.9% (23.10 - 26.60), respectively. The risk of astigmatism was significantly lower in men than in women (OR = 0.75; 95 % CI: 0.60 - 0.90). Based on multiple regression, the risk of myopia (OR = 2.07; 95 % CI: 1.60 - 2.60) and hyperopia (OR = 25.38; 95 % CI: 18.70 - 34.3) was higher in the age group 65 to 75 years compared to the younger group.

 The present study provided valuable information on the prevalence of refractive errors in the adult population in south-eastern Iran. The findings underscore the need for comprehensive eye care services, particularly for older individuals and those with lower education levels. Further prospective research is warranted to explore the factors contributing to refractive errors and to develop effective strategies for its prevention and management.

Objective measurement of visual acuity using VEP is high valued in patients with low levels of cooperation. Therefore, this study aimed to investigate the effect of spatial frequency on VEP components in visual acuity using Sweep VEP.

In this cross-sectional study 63 medical students with an age of 22.81 ± 3.93 were selected. After a completed eye examination, refractive error was determined, and best-corrected visual acuity as subjective was recorded by the Freiburg Acuity contrast test. Sweep VEP using the Roland electrophysiology system was recorded for various spatial frequencies from 2 to 37.5 cycles per degree. VEP components were the latencies of N1, P1, N135, and the amplitude of VEP.

Repeated measures of the ANOVA test showed that the effect of spatial frequency on latencies and amplitude of VEP was significant (P<0.001). Paired T-test showed that there was a significant difference between subjective visual acuity and extrapolation of visual acuity with VEP (P<0.001).

According to the significant relationship between VEP amplitude and spatial frequencies of the visual stimuli obtained in this study, the Sweep VEP technique can be used as a valid and objective tool in the determination of visual acuity, especially in patients with low levels of cooperation.

The evidence on the linear relationship between cognitive load, saccade, fixation, and task performance was uncertain. We tested pathway models for degraded task performance resulting from changes in saccadic and post-saccadic fixation under cognitive load.

Participants’ (n = 38) eye movements were recorded using a post-saccadic discrimination task with and without arithmetic operations to impose cognitive load, validated through recording heart rate variability and subjective measurement.

Results showed that cognitive load led to longer latencies of saccade and fixation; more inaccurate responses and fewer secondary saccades (P < 0.001). Longer saccade latencies influenced task performance indirectly via increases in fixation latency, therefore, longer reaction times and higher response errors were observed due to limited fixation duration on desired target.

We suggest that latency and duration of fixation indicate efficiency of information processing and can predict the speed and accuracy of task performance under cognitive load.

Background & Refraction, which is an essential component of vision care, is the determination of the amount of refractive error in the eyes. According to the existence of deprivation in different regions and the high prevalence of myopia, this study aimed to estimate and compare the agreement among three refraction methods including subjective and objective (autorefraction and retinoscopy).
Materials & This descriptive-analytical cross-sectional study was performed on 80 myopic individuals (160 eyes) referred to Razmjou-Moghaddam Clinic in Zahedan City from April to July in 2018 using a convenience sampling method. Visual acuity was first measured with a Snellen chart with and without correction and then the refractive error was determined by subjective refraction method using trial frame and objective refraction by autorefraction and retinoscope. The agreement between the parameters of sphere and astigmatism and the astigmatism axis between the three methods was calculated using the intra-class correlation coefficient index. P-value less than 5% was considered as a significant level.
The mean age was 23.0±4.1 years. Most of the participants were female (70%). Also, most of them were students (87.5%). Participants had, on average, 0.6±2.8 hours of near-eye work per day. The agreements between the three methods in measuring the spherical power of refractive errors, power, and cylinder axis were estimated to be 99%, 89%, and 69%, respectively, which were statistically significant (p<0.001). Furthermore, the mean power of the sphere was estimated to be more negative by the autorefraction method than the subjective refraction and retinoscope.
According to the high prevalence of myopia, the existence of deprivation in different regions of Sistan-and-Baluchestan province, and based on the available facilities, it seems that the subjective refraction method can be used as an alternative to objective refraction methods for evaluation of the refractive errors.

This study aimed to evaluate the distribution of contrast sensitivity (CS) using Pelli Robson test in normal individuals over seven years old living in Zahedan and examine its relationship with age, gender, and refractive errors.

In this cross-sectional study, simple sampling was performed on the patients aged over seven years and their attendants who had referred to Al-Zahra eye hospital in Zahedan. Complete ophthalmic examinations including vision and refraction assessment, biomicroscopy, and CS evaluation were carried out for all subjects. To evaluate CS, Pelli Robson chart was used at a distance of one meter. The logarithmic CS value of the last triplet in which the patient could accurately read two words was regarded as his/her CS value.

Of the 150 patients (300 eyes), 70 (46.66%) were male. The mean age of the subjects was 34.56±16.15 years (ranged from seven to 78 years). The mean and standard deviation of the CS score in two modes of monocular and binocular vision were 1.45±0.19 and 1.57±0.19 log unit, respectively. The mean CS score was not significantly different between men and women (P>0.454), but it decreased significantly with the age (P=0.000). CS was higher in individuals with emmetropia than those with myopia and hypermetropia (P=0.000). There was also a significant correlation between cylinder magnitude and CS (P=0.000).

Although Pelli Robson test evaluates CS at low and constant spatial frequencies, its distribution is significantly different among different age groups and even among individuals with different values of refractive errors.

To simplify the fitting process, this study was designed to predict the initial power of contact lenses using the regression model based on manual Javal keratometry data and refractive errors.

In this retrospective study, 121 eyes of 69 patients with keratoconus(KCN) were fitted with a specific trial set of rigid gas permeable contact lenses based on the standard criterion of “three‑point touch” over a 7‑year period. Power of the cornea was measured using Javal keratometer. Refractive errors and over refraction of patients were diagnosed using Topcon autorefractometer (RM‑A2000) and confirmed by Heine beta 2000 retinoscope.

The results of multiple linear regression showed the following equation: power of contact lens = −14.368 (constant of the final multiple regression model), +0.475 (spherical refraction), and +0.275 (flatter corneal power).

The results of this study revealed that lens power has a significant relationship with the power of the flat corneal meridian and spherical refractive error in KCN patients. The obtained regression model can be used to shorten patients’ chair time and optometric examination for predicting the power of contact lens.

To assess contrast sensitivity in clear and colored soft contact lenses under different lighting conditions.

This study was performed on 34 medical students. Visual acuity was measured using a tumbling E chart at a distance of 6 m, and contrast sensitivity was determined by Pelli Robson chart at a distance of 1 m. These tests were repeated in mesopic (3 lux) and glare (2000 lux) conditions. Then, a clear contact lens was applied to one eye and a colored contact lens was applied to the other. After 2 hr, visual acuity and contrast sensitivity were measured for each individual. The results were compared with and without contact lenses under normal, mesopic, and glare conditions.

The mean refractive error was 0.44 ± 0.20 diopters. Repeated measures ANOVA showed a decline in contrast sensitivity with colored and clear contact lenses as compared to no-lens condition (P < 0.001). Additionally, lighting conditions had a significant impact on contrast sensitivity (P < 0.001); contrast sensitivity was lower in mesopic and glare conditions than under normal lighting condition.

In addition to the drop in contrast sensitivity under unusual lighting conditions (e.g., glare and mesopic), wearing soft contact lenses can further reduce contrast sensitivity in different lighting conditions. Therefore, people who wear contact lenses should be aware of this reduction in visual performance in conditions like driving at night or in the fog.

 Binocular summation occurs in the presence of normal visual function of both eyes. Stereopsis is considered to be the finest function of binocular vision. Therefore, the aim of this study was to investigate the effect of binocular summation on contrast sensitivity and its relationship with stereopsis.

 In this cross-sectional study, 60 students of Zahedan University of Medical Sciences, Zahedan, Iran (17 men and 43 women) with a mean age of 21.20 ± 1.45 years were selected by convenience sampling method. Monocular and binocular contrast sensitivity were measured with the best corrected vision in photopic conditions using the Metrovision test for spatial frequencies of 0.75, 1.75, 3, 6, 13, and 20 cycles per degree. Stereopsis was also measured by TNO and Titmus tests. Statistical analysis was performed using the repeated measures analysis of variance (ANOVA) and multiple linear regression.

 The results of repeated measures ANOVA showed that binocular vision compared to monocular vision significantly increased contrast sensitivity (P < 0.001). But there was no significant difference between the contrast sensitivity of right and left eyes (P = 0.266). Pearson corralation test did not show a significant relationship between stereopsis measured by crossed and uncrossed methods in Titmus and TNO tests with binocular contrast sensitivity at all spatial frequencies (P = 0.114).

 Binocular summation in presence of normal binocular function can improve visual functions such as the increased binocular contrast sensitivity compared to monocular contrast sensitivity which confirms the importance of treating binocular anomalies such as amblyopia.

Age-related cataract is one of the most important causes of blindness. Early detection of cataracts can help alleviate the problems caused by this disease. This study was performed to evaluate the visual acuity and contrast sensitivity of patients with early cataract.

This descriptive-analytical study was performed on 54 patients (108 eyes) in the age range of 35 to 50 years with early stage cataract referred to Alzahra Ophthalmology Hospital in Zahedan, souh-west of Iran. The ethnicity of all the participants was Baluchi and Sistani. After correcting the refractive errors if the inclusion criteria were met, visual acuity with E chart at 6 m and Pelli Robson contrast sensitivity chart at 3 m were measured as monocular.

There was a significant correlation between visual acuity and contrast sensitivity (P=0.033, r2=0.205). The mean of visual acuity and contrast sensitivity were not significantly different in the two Baluchi and Sistani ethnicities. But visual acuity and contrast sensitivity were significantly different in the two genders (P<0.05).

Early cataract, although having a minor effect on visual acuity, can reduce contrast sensitivity. Therefore, measuring of contrast sensitivity in normal light condition in patients with early cataract who complain of blurred vision despite normal visual acuity can more accurately assess their visual function.

Glare is an unusual light condition that may alter the visual function. The aim of this study is to evaluate the effect of glare on binocular evaluation tests.

In this cross sectional study, 44 healthy students of Zahedan University of Medical Sciences, Zahedan, Iran were selected. Binocular evaluation tests were direct tests such as cover test, near point of convergence, and fusional reserves, and the indirect tests included binocular accommodative facility and relative accommodation, which were performed in the standard and glare light conditions. Statistical analysis was performed using the paired sample t-test .

The findings showed the negative fusional reserves at blur, break, and recovery point was significantly different in the two light conditions (P < 0.049). Moreover, other tests of binocular evaluation had no significant difference under the glare and normal light conditions (P > 0.050).

Given this study, glare seems to have a negative impact on negative fusional reserves. Therefore, given the limited range of negative fusional reserve, effect of unusual lighting condition should be considered, especially in people with intermittent esotropia or decompensated esophoria.

Since light scattering has a great impact on visual performances, this study was conducted to compare the effects of color filters and anti-reflective coating on contrast sensitivity (CS) in normal people under glare condition.

This semi-experimental study was conducted on 40 medical students (aged 19- 25 years). Ophthalmologic tests including visual acuity and refractive error measurement, biomicroscopy, fundoscopy, and CS assessment were conducted for all participants. CS was determined using Pelli-Robson chart at a distance of one meter. To measure the effect of glare on CS, we used an additional lighting source (60 W tungsten filament incandescent lamp) in the patient’s visual field. Thus, at an intensity of 2000 lux, the light source was placed at a distance of 18.5 cm from the patient’s eye in a way that it was 10 degrees above the subject’s visual axis. Monocular CS measurements were performed with and without glare. Monocular CS was evaluated again under glare conditions with the yellow and pink filters, with the transmission rate of 85%, and anti-reflective coating.

The mean log CS of subjects under glare (1.48±0.09) was lower than that in the absence of glare (1.71±0.09) (<0.001); moreover, repeated measures ANOVA showed the yellow filter (1.48±0.10), pink filter (1.47±0.10), and anti-reflective coating (1.47±0.09) had no significant impact on improving visual performance under glare condition (P=0.471).

Colored filters and anti-reflective coatings are not effective in enhancing the vision of young normal individuals under glare conditions and at low spatial frequencies.

Background and Age related macular degeneration is the most common cause of sever visual impairment and blindness among adults over the age of 65 years in developed countries. The purpose of this study was to review the literature on using low vision aids in age related macular degeneration and their effects on their quality of life. A comprehensive search of PubMed, Scopus and Ovid databases was conducted to identify suitable articles published until April 2015. The search keywords included: age related macular degeneration combined by optical low vision aids, non-optical low vision aids, quality of life, preferred retinal locus, telescope, and microscope. Finally 76 articles were selected. Previous studies showed that age related macular degeneration can have profound effect on an individual’s quality of life, psychological wellbeing and ability to carry out daily tasks such as driving, face recognition, reading and so on. Although new medical treatments have improved AMD’s prognosis, but vision related disability remains a major problem and the majority of the treated patients do not regain their lost vision. So, optical devices could be used as alternative treatments to help these patients and improve their visual performance. Different low vision aids such as Implantable Miniature Telescopes are designed to help the involved patients. Many studies that were conducted to evaluate the efficacy of these systems indicated the potential benefit of optical devices for patients with age related macular degeneration in improving their quality of life.

Today, contact lenses have extensive usages. Contact lens places on cornea, so it may induce variation on cornea and these variations can influence the measurement of intraocular pressure (IOP) by Goldman tonometer. The aim of this research was to study the effect of various contact lenses on measurement of intraocular pressure by Goldman tonometer. In this study, 80 subjects aged 18-25 were selected randomly among patients of Al-Zahra ophthalmology center. None of them has any eye pathological problems. Before wearing the lens, intraocular pressure was measured, and then patients were divided into two groups of soft and hard contact lenses. Soft and hard contact lenses were placed on the eye for two hours, and the intraocular pressure was measured again. The mean of IOP before wearing contact lenses and two hours later was 15.96 mmHg and 13.93, s respectively. Paired test showed a significant difference between IOP before and after wearing contact lenses (p=0.001).There was no significant differences in mean of intraocular pressure decline before and after placing the contact lens in both soft and hard lenses. According to this study, the intraocular pressure decreases after wearing contact lenses (CL). This decline may be due to variation in properties of cornea after wearing CL that can also affect IOP measurement.

Measles is one of the main causes of death among children, especially in developing countries. Although over 30 years have passed since the availability of measles vaccine; it is still uncontrolled in many countries.In Iran the highest incidence of confirmed measles cases have occurred in Sistan and Baluchistan province.. This study was conducted to determine demographic and epidemiological characteristics of measles cases in order to improve strategies to eliminate measles in this province..Patients and All suspected and confirmed measles cases from April 2006 until March 2011 were evaluated in this province.. Overall 456 suspected cases of measles were reported. 19.7% of cases were reported clinically positive, and positive test ratio was 56%. During our study measles incidence rate had increasing trend. The most incidence cases have occurred in spring and summer and the most cases have occurred in 1-4 years age group. Chabahar city has had the most confirmed cases. About measles vaccination history, 56.4% of all reported cases never vaccinated before.. Improving vaccination coverage and more accurate control of the cold chain can reduce probable outbreaks of measles and also it is proposed to expand health services in the eastern border to health control of immigrants..

Regarding the high outbreak rate of the eye disorders and problems particularly accommodation disorders and convergence insufficiency in computer users, the study tries to determine the convergence, accommodation system, condition, fusion reserves and vision dimension in bank employees (who work with computers) and the control group (who are not computer users) and then to compare the mentioned parameters in the two groups. In this cross-sectional and observational study a total of 44 bank employees and 44 people as the control group members were selected randomly. Initially, refractive problems were reformed, and then accommodation, convergence and vision dimension evaluative tests were conducted. The test included measuring the near point of convergence, jump convergence, phoria, accommodation range (one eye, both eyes), ease of accommodation (one eye, both eyes), positive and negative related accommodation, near fusion versions and TNO. Our results showed that there was a not significant difference among the near point of convergence, jump convergence, near phoria, accommodation range (one eye and both eyes), ease of accommodation (one eye, both eyes), positive and negative related accommodation in bank employees and control group. Regarding the studies, the outbreak rate of accommodation and convergence disorders is higher in bank employees than the control group which would be due to over working with computer within a fixed interval.

Iran is one of the countries implementing indoor residual spraying (IRS) for malaria control. Deltamethrin (DLT) is one of the insecticides recommended by World Health Organization (WHO) for this program. IRS is currently performed in Sistan and Baluchistan province as an area with unstable malaria situation and the highest prevalence of malaria in the country. DLT has been used since 2003 in this area. The purpose of this study is to determine IRS status of DLT in malaria elimination program in this province. In this cross-sectional study, data on workers, insecticide formulation, amount of used insecticide, the number of sprayed places, and spray coverage percent in a period of four years between 2008 and 2011 from six districts of the province were collected and analyzed. IRS was implemented by two DLT formulations (WP 5%, WG 25%) two rounds yearly. Mean of coverage percentage was 85.12±2.47 on fixed places and 95.87±2.47 for temporary places. On average, every worker sprayed in each round eight hours a day (non-continuously) by 6 to 8 pumps containing DLT at 625 to 780 mg-Lit concentration. Thus, workers were in contact with high daily doses of DLT mist. Health system must provide suitable equipment and logistics support for spraymen’s health. Also, training workers would certainly be effective. Instructing and explaining the important role of IRS in malaria prevention to households can be effective in spraying coverage augmentation.

Adverse effect of sun rays mainly UV ray on the human eye documented and protection of eyes is necessary using different methods such as, Sun Glasses. Sunglasses are designed in different colors. The aim of this study was evaluation of the effect of different colors of sunglasses on the visual acuity, contrast sensitivity, stereopsis and color vision. 81 normal subjects were selected randomly from students of Zahedan medical university with average age of 21 years. Then we evaluated visual acuity by snellen chart, contrast sensitivity by Cambridge low contrast grating chart, stereopsis with TNO test and color vision with D15 test in the room (normal space) with illumination of 991 lux and in the sun with illumination of 54000 lux with and without filters (Polaroid gray, green, brown and gray). The mean of visual acuity was 10/10 in room and sun. Paired t test didnt show significantly difference between contrast sensitivity in room and sun condition (p>0.05). Anova analysis showed significantly difference between stereopsis with and without colored filter (p<0.05). There wasn’t significant different between color vision with and without colored filer in sun (p>0.05). Sunglasses increase contrast sensitivity in the sun and the gray and brown filter increase contrast sensitivity more than the others colors and also these colors had less effect in reduce of stereopsis.

To evaluate the effect of induced esophoria and exophoria on distance stereoacuity at 6 meters Fifty subjects with distance corrected or uncorrected visual acuity of 6/6 and orthophoria without history of amblyopia, strabismus or any ocular pathology were recruited and distance stereoacuity was measured by Howard-dolman test before and after introducing 2, 4, 6 and 8Δ base in and base out to induce esophoria and exophoria, respectively. Although the decrease in stereoacuity was not significant by introducing 2Δ base in prism (P=0.062), but it was significant statistically by introducing 4 and 6Δ base in (P=0.002, P=0.026, respectively) and 2, 4, 6, 8Δ base out (P=0.042, P<0.001, P<0.001, P<0.001, respectively) prisms compared with orthophoric position. There was no significant difference between stereoacuity in 2Δ and 4Δ induced esophoria with 2Δ and 4Δ induced exophoria (P=0.696, P=0.677, respectively), but 6Δ induced esophoria decreased stereoacuity more than induced exophoria of the same amount (P=0.007). Induced heterophoria at distance of 6 meters reduced stereoacuity measured by modified Howard-Dolman test. Greater than 4Δ of induced esophoria had statically and clinically adverse effect on distance stereoacuity.

Several studies have reported high prevalence of severe lack of cobalamine and Folate in aged people. The most important causes are: malnutrition, atrophic gastritis and drug use. Age related macular degeneration (ARMD) is a primary degenerative disorder of central retinal area with loss of visual acuity. Recent studies have shown a significant relationship between age related macular degeneration and lack of plasma level of Folate, red blood cells and cobalamine. This study was caried out to investigate the relationship between age related macular degeneration and plasma Folate, Cobalamine and photostress recovery time, in elderly population.

This case – control study was done on 124 elderly population. The participants were collected from by cluster sampling in mashhad located in the Noth – East of Iran during 2006. The patients underwent eye examination including indirect ophthalmoscopy. Slit lamp examination and photostress recovery time for age related macular degeneration by an ophthalmologist. After blood sampling, plasma Folate, serum Cobalamine, were determined by RIA method (DRG kit).

The Mean+-SD of cobalamin and folate in age related macular degeneration patients was 298.848+-288.66 pg/ml and 5.543+-3.58 ng/ml and in normal group was 310.775+-531.38 pg/ml and 5.365+-3.52 ng/ml. There was no significant difference between age related macular degeneration patients and control group. Photostress recovery time was significantly increased in patients with age related macular degeneration (P<0.05). There was no significant relationship between photostress recovery time and Cobalamine and folate level.

This study showed that serum cobalamin and folate non significantly is decreased in age related maucular degeneration patients, with increasing photostress recovery time, we can use this screening test for the dignosis of age related macular degenertion.

To determine the effect of occluding a normal eye on visual acuity, contrast sensitivity and stereopsis in amblyopic school children. Amblyopic children from primary schools of region 2 in Mashhad were identified and referred to Optometry Clinics of Mashhad Medical University through a screening program. Informed consent was obtained from the parents. All subjects underwent an ophthalmologic examination including visual acuity, subjective refractive error, biomicroscopy and funduscopy. Best-corrected visual acuity (BCVA), contrast sensitivity and stereopsis were measured by Snellen E chart, Cambridge low contrast chart and Titmus stereotest, respectively. All tests were repeated 2 weeks, 1 month and 3 months after initial examination. Of 1,947 children, 289 (14.8%) were amblyopic of whom 62 subjects were eventually enrolled for the study. BCVA in the amblyopic eye was less than 3/10 in 25.8% of subjects before treatment however all children had BCVA of 3/10 or better afterwards. Mean BCVA in amblyopic eyes significantly increased from 0.53±0.26 logMAR to 0.24±0.23 logMAR after 2 months of treatment (P<0.001). Mean contrast sensitivity in amblyopic eyes was 68.3 before treatment which improved to 152.5, 138.2 and 198 after 2 weeks, 1 month and 2 months of treatment, respectively (P<0.001). Contrast sensitivity may provide better assessment of visual function as compared to visual acuity. Changes in contrast sensitivity are more sensitive to occlusion therapy as compared to visual acuity. Therefore, contrast sensitivity may yield better evaluation of subclinical changes not detectable by testing visual acuity.