PURPOSE: To compare ocular aberrations measured with a laser ray tracing aberrometer (iTrace(R), Tracey technology) or a Shack-Hartmann aberrometer (Zywave(TM), Bausch & Lomb). METHODS: A total of 68 eyes were included in this study. After manifest refraction (MR) and pupil dilation, aberrations and phoroptor predicted refraction (PPR) were measured with the Zywave(TM) and iTrace(R) devices. The study group was subdivided into a more myopic group (<-4.33 Diopter (D)) and a less myopic group (>-4.33 D). The root mean square (RMS) errors of the total high order, spherical, coma and 3rd~5th order aberrations were compared. RESULTS: The mean and SE of MR was -4.33+/-2.03 diopter (D), and that of the PPR was -4.20+/-2.13 D in iTrace(R) and -4.42+/-2.23 D in Zywave(TM). A paired-t test of the PPR and MR indicated that they were not statistically different. Zernike coefficients were expressed in the opposite sign in the 2nd and 4th order. The coma and spherical aberrations were larger in Zywave(TM). In a scattergram of each Zernike coefficient, the coefficient of determination (R2) was very low with higher order aberrations, with an exception for coma and spherical aberrations. The correlation of RMS error was greater in the less myopic group. CONCLUSIONS: Taking PPR values as a good reference of MR was a reliable method. For the HOA, only coma and spherical aberrations showed good correlations between Zywave(TM) and iTrace(R), and the correlations for HOA were decreased for the high myopic eyes.
Coma ; Pupil

We measured apparent accommodation in 40 contact lens wearing monocular aphakic eyes (40 patients). The mean apparent accommodation was 1.74 +/- 0.73 diopters. The apparent accommodation was not influenced by the target size. There was no primary correlation between apparent accommodation and reciprocal of pupillary diameter, but significant difference between apparent accommodation of small pupil group(pupil group(>or=7.0mm). It suggests that apparent accommodation is influenced by the pupil size in aphakic eyes. Accommodation of phakic eyes was significantly greater than apparent accommodation of contralateral aphakic eyes in the group of age between 45 and 55.
Miosis ; Pupil

The study aims to investigate whether any change the prevalence of anaemia at primary school. Two cross-sectional studies were conducted on the pupils at Dong my school, Thanh Tri distric of Hanoi suburban in 1997 and 1999. Haemoglobin concentration determination was used by cyanmethemoglobin method. The dietary food intake by 3 days repeated 24 hours recall method. The classification of nutritional anaemia base on the levels of haemoglobin recommened by WHO. The results showed that: the prevalence of nutritional anaemia of the pupils in 1997 was 37.7%, boys 41%, girls 33.3% and 13.1%, boys 15.5% girls 12.2%. The dietary food intake: energy 1,118 +/- 279.9 kcal, protid 41.6 +/- 15.3 g, vitamin C 62.4 +/- 98.6 mg, higher than in 1997 (962+/- 136 Kcal, 34.0 +/- 7.5 g protid and 27.8 +/- 16.5 mg vitamin C). There was no difference of the avarage of haemoglobin concentration between boys and girls group. The average of haemoglobin concentration was statistic significantly higher in 1999 than in 1997 as well as the prevalence of nutritional anaemia in 1998 than 1999.
Anemia ; pupil

A study on learning sitting position and the suffering from spinal deformation of 2771 pupils were conducted in 4 grades at 4 districts belong to Hanoi. The result showed that: there is a close relationship between learning sitting position and the suffering from spinal deformation of pupils. The rate of pupils have the right learning sitting position is highest in the first grade of primary school. Later on, due to neglecting remind from teachers and parents regularly, these pupils start having wrong learning sitting position, especialy writting sitting position. Results: 12% pupils in wrong learning sitting position and nearly 19% pupils suffering from spinal deformation. In order to prevent this situation, an overall methods and care from multi branches, levels as well as education and communication solutions need to be carry out. The teachers’s responsibilities and people’s awareness and knowledge, pupils’s awareness and practical skills need to be strengthen and it is the key method.
Pupil ; Spine

Studies on 5,050 pupils at 3 levels of primary education in Ha Noi, Nam Dinh and Thai Nguyen during 1999-2001 showed that: the myopia of pupils had increased by the learning grade. The myopia rate of pupils in urban areas is higher than that in suburb areas. Some factors were related closely to the rate of myopia including the lighting level inside classes, the dimensions of tables and desks, the sitting position of pupils in classes
Myopia ; Pupil

By utilising the cross- sectional study method, we have investigated the physical status and the diseases prevalence of the Tran Phu aptitude pupils (594 girls and 505 boys) school. Basing on obtained material analysing we have some following results. In comparision with the other pupils in Hai Phong, the eyes diseases prevalence of the Tran phu aptitude pupils school are higheast (33.2%), the short sighted (myopia) ratio is 31.2%.
Pupil ; Disease

No abstract available.
Neurosyphilis ; Pilocarpine ; Tonic Pupil

OBJECTIVE: The goal of this study was to develop a novel pupil and iris segmentation algorithm. We evaluated segmentation performance based on a fractal model. Two methods were compared: Daugman's and our new proposed method. METHODS: We received 200 anterior segment images with 3,872x2,592 pixels. Here we present an active contour model that accurately detects pupil boundaries in order to improve the performance of segmentation systems. We propose a method that uses iris segmentation based on a fractal model. We compared the performance of Daugman's method and the proposed new method and statistically analyzed the results. RESULTS: We manually compared segmentation with the Daugman's method and the new proposed method. The findings showed that the proposed segmentation accuracy was about 2.5 percent higher than Daugman's method. There was a significant difference (p<0.05) between the under and over data between the two methods. CONCLUSION: The results of this study show that the new proposed method was more accurate than the conventional method for the measurement of segmentation of the eye by CAD (Computer-aided Diagnosis).
Eye ; Fractals ; Iris ; Pupil

PURPOSE: The present study investigates the patterns of internal optical aberrations in eyes with different types of cataract. METHODS: Eighty eyes of 70 cataract patients were included in the present study. Internal optical aberrations were measured with a KR-1W wavefront aberrometer before cataract operation. Types of cataract were classified into three groups; cortical, nuclear and posterior subcapsular cataracts. The differences in the results of the wavefront data of 6-mm pupil diameter zones were compared among three groups. The Kruskal-Wallis test and Mann-Whitney U test were used for comparing data. RESULTS: A total of 80 eyes consisting of 30 cortical cataracts, 30 nuclear cataracts and 20 posterior subcapsular cataracts were found. In the 6-mm pupil diameter zone, the average internal spherical aberrations by original value were 0.042 microm of cortical cataracts, -0.092 microm of nuclear cataracts and -0.109 microm of posterior subcapsular cataracts. The average internal spherical aberrations by absolute value were 0.122 microm of cortical cataracts, 0.533 microm of nuclear cataracts and 0.202 microm of posterior subcapsular cataracts. The internal spherical aberrations by original value were not statistically significantly different, but by absolute value were statistically significantly different (p = 0.003, Kruskal-Wallis test). Nuclear cataracts have a much higher positive or negative value than other cataract groups in the distribution of internal spherical aberrations by original value for each type of cataract. Other than this difference, the internal astigmatism and internal high order aberrations were not statistically significantly different. CONCLUSIONS: The change in internal spherical aberrations of nuclear cataract from the original value was larger than cortical and posterior subcapsular cataract. Therefore, nuclear cataracts have much higher positive or negative values than other cataract groups.
Astigmatism ; Cataract* ; Humans ; Pupil

We performed coreoplasty on drawn pupils(17 eyes) by using Argon laser only or Argon laser combined with Q-switched Nd:YAG laser from June 1983 to May 1989. The results were as follows; 1. The causes were divided by 7 eyes(41.2%) with trauma and 10 eyes(58.8%) without trauma. 2. There were 15 eyes(88.2%) in up-drawn pupils and 2 eyes(11.8%) in downdrawn pupils. 3. The degree of preoperative drawn pupil was 1.42mm in average and enlargement of postoperative drawn pupil was 1.25mm in average. The corrected effect for preoperative drawn pupil and postoperative drawn pupil and postoperative drawn pupil was shown as 2.58mm in average. 4. Postoperative corrected visual acuity improved fairly. It was same as preoperative corrected visual acuity in 4 eyes(23.5%) and improved in 13 eyes(76.5%).
Argon ; Pupil ; Visual Acuity