Evaluation of the relationship between internet addiction and interpersonal relationships in university studentsin Japan.

With the popularization of the internet, internet addiction among the youth has received a lot of attention in recent years. While.the internet is an effective tool for: communication, the youth, who find real-life communication difficult, reportedly overuse,this aspect of the internet However, this is more of an impression based on clinical cases, with few factual findings. Therefore, the aim of this research was to study the reality of internet addiction -among university students and to examine the multilateral relationship between internet addiction and interpersonal relationships. We conducted a questibnnaire stirvey among 221 uriiversity students, analyzing the level of internet addiction, relevant interpersonal relationships, personal "charcteristics, and other factors associated with internet use. We found that the number of students who were dependent on the internet was 10 (4.7%) and the number of students with a tendency toward dependency was 98 (45.6%). In interpersonal relationships, internet addiction was significantly correlated with parental overprotection, a sense of contentment from the present parent-child rela- tionship, relationships with friends, number of friends, and availability of free time. In personal characteristics, internet addiction was significantly correlated with social skills and feelings of self-esteem. In other factors, internet addiction was significantly correlated with typing on a message board, video browsing, online gaming, use of a personal computer, desire to escape, distraction, pleasure, and connecting with others. Furthermore, we conducted a multiple regression analysis to consider the effects of these three aspects associated with internet addiction. The results suggest that internet addictionl is promoted by parental overprotection, low self-esteem, having few friends, and passive internet service usage. Thus, education is required to promote careful use of the internet to prevent internet addiction from escalating. Further, it is important to understand and support interpersonal relationships to prevent internet addiction from making life worse.

Scleral birefringence as measured by polarization-sensitive optical coherence tomography and ocular biometric parameters of human eyes in vivo.

The relationship between scleral birefringence and biometric parameters of human eyes in vivo is investigated. Scleral birefringence near the limbus of 21 healthy human eyes was measured using polarization-sensitive optical coherence tomography. Spherical equivalent refractive error, axial eye length, and intraocular pressure (IOP) were measured in all subjects. IOP and scleral birefringence of human eyes in vivo was found to have statistically significant correlations (r = -0.63, P = 0.002). The slope of linear regression was -2.4 × 10(-2) deg/µm/mmHg. Neither spherical equivalent refractive error nor axial eye length had significant correlations with scleral birefringence. To evaluate the direct influence of IOP to scleral birefringence, scleral birefringence of 16 ex vivo porcine eyes was measured under controlled IOP of 5-60 mmHg. In these ex vivo porcine eyes, the mean linear regression slope between controlled IOP and scleral birefringence was -9.9 × 10(-4) deg/µm/mmHg. In addition, porcine scleral collagen fibers were observed with second-harmonic-generation (SHG) microscopy. SHG images of porcine sclera, measured on the external surface at the superior side to the cornea, showed highly aligned collagen fibers parallel to the limbus. In conclusion, scleral birefringence of healthy human eyes was correlated with IOP, indicating that the ultrastructure of scleral collagen was correlated with IOP. It remains to show whether scleral collagen ultrastructure of human eyes is affected by IOP as a long-term effect.

Anisotropic alteration of scleral birefringence to uniaxial mechanical strain.

PURPOSE: To investigate the relationship between scleral mechanical properties, its birefringence, and the anisotropy of birefringence alteration in respect of the direction of the strain by using PS-OCT. METHODS: The scleral birefringence of thirty-nine porcine eyes was measured with a prototype PS-OCT. A rectangle strip of sclera with a width of 4 mm was dissected at the temporal region 5 mm apart from the optic nerve head. The strain and force were measured with a uniaxial tension tester as the sample was stretched with a speed of 1.8 mm/min after preconditioning. The birefringence of the sample was measured by PS-OCT at the center of the sample before applying, denoted as inherent birefringence, and after applying stretching of 6.5% strain. The birefringence alteration was obtained by these two measurements and correlations between birefringence and elastic parameters, tangent modulus, and structural stiffness were examined. Twenty and 19 porcine eyes were stretched in meridional or equatorial directions, respectively. RESULTS: A moderate positive correlation was found between the inherent birefringence and the structural stiffness. A moderate positive correlation was also found between the inherent birefringence and the tangent modulus. The birefringence increased by strains. Marginal significance was found in the birefringence alteration between meridional and equatorial strains, where the mean birefringence elevation by meridional strain was higher than that by equatorial strain. CONCLUSIONS: The birefringence was found to be altered by applying strain and also be related with inherent birefringence. This implies the birefringence of the sclera of the in vivo eye also could be affected by its mechanical property.

High-penetration optical coherence tomography with enhanced depth imaging of polypoidal choroidal vasculopathy.

A combination of high-penetration spectral-domain optical coherence tomography (central wavelength: 1,020 nm) and an enhanced depth imaging protocol (HP-EDI-OCT) was used to evaluate 5 eyes of 5 patients with polypoidal choroidal vasculopathy (PCV). In all eyes, HP-EDI-OCT provided high-contrast images of PCV lesions in the subretinal pigment epithelium (sub-RPE). In the space between the RPE line and Bruch's membrane, various PCV lesions, including vascular networks, polypoidal lesions, and sub-RPE hemorrhage, were clearly identified. The chorioscleral interface was clearly observed, and the entire structure of the choroid was readily identified. Thus, HP-EDI-OCT was useful for evaluating sub-RPE lesions of PCV.