Background: Taking visual acuity is an important part of an eye routine examination. This study was conducted to compare visual acuity measured using an Iranian digital tumbling E chart with visual acuity measured using an Italian digital tumbling E chart as a familiar foreign chart.Materials and Methods: This study was carried out on 200 participants (400 eyes; healthy n=40, glaucoma n=40, retinal disorders n=40, post lasik n=40, corneal n=40) with mean age 44.28 years. visual acuity of both eyes in half of the subjects (n=100, n=20 from each group) was first measured using the Italian digital chart and then measured using Iranian digital chart. visual acuity of the rest of subjects (n=100, n=200 from each group) was first measured using the Iranian digital chart and then measured using the Italian digital chart. Measured visual acuities were recorded in logMAR notation.Results: Mean of the Iranian and Italian Tumbling E chart is 0.280 ± 0.012 and 0.277±0.012, respectively. Paired t-test used to evaluate the mean difference between two groups (p=0.721) indicated that there was no statistically significant difference between means of the two tests. Spearman correlation coefficient for the results of both tests was 0.942 (p<0.001), which was statistically significant and could be categorized as a strong positive correlation.Conclusion: The two digital Tumbling E charts acted similarly at different levels of acuity in different disorders. However, the Iranian chart requires a more accurate design for optotypes of the lower acuity lines in order to obtain more accurate measurement of visual acuities in healthy subjects.

In this article, a smart visual acuity measurement (VAM) system is designed and implemented. Hardware of the proposed VAM system consists of two parts: a wireless remote controller, and a high-resolution LCD controlled through a Raspberry-Pi mini-computer. In the remote controller, a 3. 5” graphical LCD with a touch screen is used as a human-machine interface. When a point is pressed on the touch screen, the unique identifier (ID) code of that point as well as its page number is transmitted to the Raspberry-Pi. In the Raspberry-Pi, data are received and processed by a smart application coded in visual studio software. Then, the commanded tasks are executed by the Raspberry-Pi’s operating system. Numerous charts, characters, and pictures are stored in the proposed VAM system to provide various VAM options while the size of the optotypes is adjusted automatically based on the distance of the patient from the LCD. The performance of the proposed VAM system is examined practically under the supervision of an expert optometrist where the results indicate that visual acuity, astigmatism, and color blindness of patients can be examined precisely through the proposed VAM system in an easier and more comfortable manner.

measurement of visual acuity (VA) has been used for eye examinations under various clinical conditions. In addition, because of changes in VA with a range of eye diseases, its measurement is used to screen, diagnose, and evaluate response to treatment in numerous eye diseases and predict the patient's visual function. VA and the likelihood of astigmatism could be evaluated simultaneously using a newly designed Stripped Circle (SC) VA chart. This chart has been developed based on the standard VA measurement scale chart, and the Landolt-C (LC) VA chart and all the standards for a VA chart design were implemented during its development. However, to publicize the clinical application of this VA measurement chart, further studies are required to evaluate its sensitivity, specificity, and repeatability compared with a similar standard VA chart.

Purpose: To determine the visual acuity (VA) impairment in patients with retinitis pigmentosa (RP) in different age groups. Materials and Methods: This descriptive study was extracted from the recorded data in the National Registry for Inherited Retinal Diseases (IRDs) in Iran (IRDReg®, ). The clinical records of 441 patients with a diagnosis of RP were investigated in the present study. The comprehensive visual and ocular examination with retinal imaging were conducted for all study subjects to ascertain the definite clinical diagnosis of RP. VA was classified based on the presenting VA (PGVA) of the better eye according to the International Classification of Diseases reported by the World Health Organization (WHO). Results: In this study, a total of 441 RP patients with the mean age of 38. 66 ±,14. 24 years (range, 4 to 74) were included. Generally, the majority of RP patients in the age range of 20 to 40 years had visual impairment (80%,95% CI, 74. 3% to 84. 9%). RP patients with younger ages had mild visual impairment (26. 3%,95% CI, 14. 4% to 41. 7%), while patients with no light perception was only found in older ages (3. 4%,95%CI, 1. 4% to 6. 8%), (P<0. 001). The most frequency of RP patients suffering from visual impairment had disease onset at age ≤, 20 years (82. 0%,95% CI, 77% to 86. 2%), and also severe visual impairment was observed in patients with earlier disease onset (2. 6%,95% CI, 1. 2% to 5. 1%), (P=0. 001). Conclusion: Based on our findings, more disease progression and subsequently visual acuity reduction was observed in RP patients who had older ages and disease onset in younger ages.