Purpose: Stereopsis in normal subjects aged between 7 and 76 years was compared to examine changes in stereopsis with age. Methods: Eighty subjects with no ocular disease were divided into 8 groups by age. Near stereopsis was evaluated with the TNO, Titmus, and Randot tests; distance stereopsis with the Mentor B-VAT II video acuity tester. Results:The results of all 4 tests showed decreased stereopsis with increasing age (p<0.05). Compared to the stereoacuity of 7 to 10-year-old group, both the TNO and distance stereopsis test results were significantly decreased for the 6th, 7th, and 8th decade groups, while both the Titmus and Randot test results were significantly decreased for the 8th decade group (p<0.05). Conclusions: Overall, both near and distance stereopsis decreased with increasing age. Thus, decreased stereopsis should be taken into account when performing the stereopsis test.

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The prevalence of myopia has been increasing worldwide. Its causes are not completely clear, although genetic and environmental factors are thought to play a role. Data were collected by the Korean Military Manpower Administration. Frequency analysis was used for comparisons of general characteristics. Pearson’s chi-square tests and logistic regression analysis were used to verify the correlations between possible risk factors and the prevalence of myopia or high myopia. The prevalence of myopia (50.6–53.0%) and high myopia (11.3–12.9%) increased each year. These tended to be the highest in patients born in spring, and decreased in the following order according to education level: 4- or 6-year university education or more, high school education or less, and 2- to 3-year college education. Moreover, the prevalence of myopia and high myopia was significantly higher in patients ≤ 60 kg and with a body mass index ≤ 18.5 kg/m2. The prevalence of high myopia was significantly higher in taller patients (≥175 cm). The prevalence of myopia and high myopia increased each year in Korean young adult men and was associated with birth season, education level, height, weight, and body mass index. Tall, lean men were more likely to have high myopia.

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PurposeWe analyzed the effect of the changes of the optic disc area (ODA) caused by the axial length and the refractive error, and the consequent changes of the distance from the optic disc margin to the circular scan (OD-CS) of Optical coherence tomography (OCT) on the measurement of the retinal nerve fiber layer thickness(RNFLT) were examined.MethodsOne hundred two eyes of 51 children (age range 4 to 15 years) were measured using OCT including the RNFLT. For the ODA and the OD-CS, the relative area formed by the ODA and the circular scan was obtained. In addition, the correlation of the refractive error and the axial length to the optic disc factors was assessed.ResultsAs hyperopia progresses to myopia, the axial length became longer, the ODA became smaller (r=-0.442, p=0.000) and the OD-CS showed a tendency to increase (r=0.471, p=0.000). As the OD-CS became longer, the measured average RNFLT decreased significantly (r=-0.248, p=0.012), and the ODA and the ODCS showed a significant correlation to the RNFL thickness that was measured in the nasal and inferior areas, the S2, N2 and N3 areas and the I1 area.ConclusionsAs ODA becomes smaller and the OD-CS becomes longer, the RNFLT measured in the nasal and inferior areas, the S2, N2, N3, I1 area has a tendency to be thinner. Hence, consideration of the disc area is required when interpreting the RNFLT of these eyes.

BackgroundSeveral inferior oblique (IO) weakening methods exist for correction of superior oblique palsy (SOP). A previously reported method involved recession and anteriorization according to IO overaction (IOOA) grade, which might be subjective and cause upgaze limitation and opposite vertical strabismus. Therefore, this study attempted to examine the efficacy of modified graded recession and anteriorization of the IO muscle in correction of unilateral SOP without resulting in upgaze limitation or opposite vertical strabismus.MethodsA total of 26 patients (male, 16; female, 10; age: 3–40 years) with SOP and head tilt or diplopia underwent modified graded recession and anteriorization. Patients were grouped by the position at which the IO muscle was attached inferior/temporal to the lateral border of the inferior rectus (IR) as follows: (1) 7.0/2.0 mm (4 patients), (2) 6.0/2.0 mm (3 patients), (3) 5.0/2.0 mm (3 patients), (4) 4.0/2.0 mm (11 patients), (5) 3.0/0.0 mm (2 patients), and (6) 2.0/0.0 mm (3 patients). Recession and anteriorization were matched to vertical deviation in the primary position at far distance. Remaining diplopia, head tilt, vertical deviation (≤3 prism diopter (PD), excellent; 4–7 PD, good; and ≥ 8 PD, poor), upgaze limitation, and opposite vertical strabismus were evaluated.ResultsThe average pre and postoperative 1-year vertical deviation angles in the primary position at far distance were 15.0 ± 5.6 PD and 1.2 ± 2.0 PD, respectively. At 1 year post-surgery, the vertical deviation angles were reduced by 6.8–21.0 PD from those at baseline. Few patients exhibited remaining head tilt, diplopia, upgaze limitation, or opposite vertical strabismus. Correction of hypertropia was excellent in 22 and good in 4 patients.ConclusionsModified graded recession and anteriorization of the IO muscle is an effective surgical method for treating unilateral SOP. It exhibits good results and reduces the incidence of opposite vertical strabismus.Electronic supplementary materialThe online version of this article (doi:10.1186/s12886-017-0422-6) contains supplementary material, which is available to authorized users.

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We studied the relationship between eye position in the awakened state and in the surgical plane of anesthesia in orthophoric and horizontal strabismus patients. We classified 105 orthophoric and horizontal strabismus patients into 5 groups, measured the eye position at the primary position by photographic measurement of the corneal reflex positions and undertook a quantitative study of eye position. Under general anesthesia, the mean divergence was 39.7+/-8 PD for the esotropia group, 36.6+/-11.7 PD for exophoria, 27.4+/-8.1 PD for orthophoria, and 11.1+/-10.2 PD for exotropia I (< or =30 PD). Therefore, the esotropia group had the largest amount of divergence among the groups, but the eye position of the exotropia II (>30 PD) group was rather convergent at 11.0+/-6.5 PD. According to the eye position of the fixating and nonfixating eyes in the esotropia group, both eyes converged with an angle deviation of 14.4+/-4.8 PD divergent and 14.1+/-4.8 PD divergent, respectively (P=.71). In the exotropia groups (I, II), the fixating eye diverged but the nonfixating eye rather converged. Therefore, the angle deviation was 19.0+/-2.1 PD divergent for the fixating eye and 18.2+/-6.4 PD divergent for the nonfixating eye (P=.68). In conclusion, under general anesthesia, eye positions in the awakened state and in the surgical plane of anesthesia were convergent or divergent, and showed a tendency to converge into the position of 25-35 PD divergent. Therefore, we could not distinguish fixating eye from nonfixating eye under general anesthesia.