Inter-Eye Association of Visual Field Defects in Glaucoma and Its Clinical Utility.

Purpose: To investigate intereye associations of visual field (VF) defects. Methods: We selected 24-2 VF pairs of both eyes from 63,604 patients tested on the same date with mean deviation (MD) ≥ -12 dB. VFs were decomposed into one normal and 15 defect patterns previously identified using archetypal analysis. VF pattern weighting coefficients were correlated between the worse and better eyes, as defined by MD. VF defect patterns (weighting coefficients > 10%) in the better eye were predicted from weighting coefficients of the worse eye by logistic regression models, which were evaluated by area under the receiver operating characteristic curve (AUC). Results: Intereye correlations of archetypal VF patterns were strongest for the same defect pattern between fellow eyes. The AUCs for predicting the presence of 15 defect patterns in the better eye based on the worse eye ranged from 0.69 (superior nasal step) to 0.92 (near total loss). The AUC for predicting superior paracentral loss was 0.89. Superior paracentral loss in the better eye was positively correlated with coefficients of superior paracentral loss, central scotoma, superior altitudinal defect, nasal hemianopia, and inferior paracentral loss in the worse eye, and negatively correlated with coefficients of the normal VF, superior peripheral defect, concentric peripheral defect, and temporal wedge. The parameters are presented in the descending order of statistical significance. Conclusions: VF patterns of the worse eye are predictive of VF defects in the better eye. Translational Relevance: Our models can potentially assist clinicians to better interpret VF loss under measurement uncertainty.

Male contraception: Prospects for sound and ultrasound.

The worldwide human population growth rate, which doubled during the 20th century, as well as the increasing fertility rate, have contributed to an increasing and evolving emphasis on contraception. With respect to female contraceptive methods, many have been developed, marketed, and are widely available. In contrast, male contraception has been limited to condoms, which pose logistical challenges, and vasectomy, which is largely irreversible. The use of sound to achieve effective and safe male contraception is a promising but unproven hypothesis. Based on the existing and incomplete totality of evidence, we hypothesize that the combination of sound with a modified ultrasonic technique in a single system will provide a practical delivery method that merges all of the appropriate and prescribed frequencies to have spermicidal qualities that may result in effective and safe male contraception. It is also plausible that any experimental male contraceptive method that heats the testicles where they can no longer produce sperm offers the possibility of a favourable benefit to risk ratio. The single system combining sound with a modified ultrasonic technique includes an acoustically suitable pad to assure proper transmission and delivery without concern for injury from the ultrasound frequencies, an amplification and regulation module, a frequency source generator, the complementary heat created along with external and targeted directionality, and various transport methods, such as wired, wireless, or remote. This methodology also offers the ability to move quickly to prototype, achieve multiple patent crossovers, secure and employ commercially available technologies, and provide the opportunity for rapid regulatory approval worldwide. These concepts have been explored in basic research in many animal species as well as humans. To achieve an adequate totality of evidence, the test of this hypothesis requires further basic research in humans to clarify the relevant mechanisms, clinical and observational epidemiologic studies to further explore the hypothesis, and large-scale randomized trials to detect the most plausible magnitude of benefits of this promising but unproven technology. It is plausible that this technology will represent a major breakthrough to combat world population growth. It is also plausible, that, to paraphrase Thomas Huxley, this beautiful hypothesis will be slain by ugly facts.