ABSTRACT
Purpose: To investigate the association between early lifetime substance use on the development of severe visual acuity impairment or blindness on a national level. Methods: National Survey of Drug Use and Health data was used to identify cases of substance use before 21* years of age, within the past year, and cases of self-reported blindness or visual impairment. Univariable and multivariable binary logistic regression with time-dependency was performed to evaluate odds of visual impairment influenced by 16 substances separated into three classes: prescription, non-prescription, and illicit drugs. Adjusted variables of interest included gender, marital status, race, level of education, total family income, poverty level, population density, and history of chronic disease. Results: 55,824 total responses were analyzed with 2577 (4.6%) cases of self-reported blindness or significant visual impairment. All early-use substance categories, including prescription, non-prescription, and illegal substances, were significantly associated with self-reported VI (OR 2.068, CI 1.451-2.949, p<0.001; OR 1.352, CI 1.227-1.489, p<0.001); OR 1.211, CI 1.086-1.352, p<0.001), respectively). Non-prescription substances displayed parallel significances amongst all constituents (alcohol, cigarettes, inhalants, and marijuana) (OR=1.227, CI 1.12-1.344, p<0.001; OR 1.363, CI 1.243-1.495, p<0.001; OR 1.418, CI 1.134-1.774; OR 1.388, CI 1.27-1.518, p<0.001, respectively). Univariable and multivariable analysis revealed several significant demographical and clinical adjustors. Conclusion: Early lifetime use of all three classes of substances is associated with enhanced odds of subsequent visual impairment or blindness. Several readily available and commonly used substances have a greater risk. These findings may help clinicians and public health agencies in mitigation ventures including education, prevention, and rehabilitation efforts.
ABSTRACT
BACKGROUND: The reverse distribution pattern (RDP), in which resting perfusion imaging demonstrates a de novo or more marked regional defect than that present in stress images, is observed frequently in patients with a low likelihood of coronary artery disease. METHODS AND RESULTS: To determine whether this scan pattern is artifactual and to investigate its causes, we retrospectively evaluated scans in 202 patients with a low likelihood of coronary artery disease (77 men and 125 women) undergoing single-day rest/stress technetium-99m sestamibi single photon emission computed tomography (SPECT). The presence and location of RDP was correlated with relevant body habitus parameters. RDP was observed in 15.3% of patients. The finding was significantly more frequent in patients who were obese (P<.02 in men, P<.03 in women), in men with abdominal protuberance (P<.05), and in women with prominent breast "shadows" observed on planar projection images (P<.008). RDP was most frequent in the right coronary artery territory in men and the left anterior descending coronary artery territory in women. It was demonstrated by means of a cardiac SPECT phantom experiment that soft tissue attenuation effects were most evident in low count density SPECT studies with localized soft tissue attenuation, accounting for the higher than clinical observation of RDP in obese patients undergoing low-dose rest/high-dose imaging. CONCLUSIONS: RDP is a frequently encountered artifact in obese patients undergoing rest/stress Tc-99m sestamibi SPECT, particularly in men with abdominal protuberance and in women with large, dense breasts.