Showing papers by "Byron L. Lam published in 2008"
TL;DR: Optic disc drusen patients with more-than-expected visual field defects or progressive visual loss should have work-up to exclude other causes and to avoid overlooking potential serious conditions such as true papilledema.
Abstract: Optic disc drusen are acellular calcific deposits occurring in small, crowded optic discs with abnormal vasculature. Evidence suggests axoplasmic transport alteration and axonal degeneration are involved in disc drusen formation. In affected patients, the number and size of disc drusen are highly variable, and the drusen may be visible near the disc surface or buried within the disc, causing them to appear as pseudopapilledema. B-scan echography is the most sensitive method for detecting disc drusen. Most patients with disc drusen are asymptomatic, but progressive visual field loss and vascular complications, including anterior ischemic optic neuropathy and choroidal neovascularization, may occur. Optic disc drusen have no established effective treatment. Diagnosing disc drusen correctly is important to avoid unnecessary work-up and to avoid overlooking potential serious conditions such as true papilledema. Disc drusen patients with more-than-expected visual field defects or progressive visual loss should have work-up to exclude other causes.
88 citations
TL;DR: Visual impairment may be associated with an increased risk of suicide through its effect on poor health, and improved treatment of visual impairment and factors causing poor health may potentially reduce suicide risk.
Abstract: Objective To examine the relationship between reported visual impairment and suicide mortality. Methods From 1986 through 1996, annual cross-sectional multistage area probability surveys of the US civilian noninstitutionalized population living at addressed dwellings were conducted by the National Center for Health Statistics. We performed mortality linkage through 2002 with the National Death Index of 137 479 adults 18 years and older. The relationships between reported visual impairment and suicide were examined using structural equation modeling. Results The mean duration of follow-up was 11.0 years, and 200 suicide deaths were identified. After controlling for survey design, age, sex, race, marital status, number of nonocular health conditions, and self-rated health, the direct effect of visual impairment on death from suicide was elevated but not significant (hazard ratio, 1.50; 95% confidence interval, 0.90-2.49). The approximate indirect effect of visual impairment on death from suicide via poorer self-rated health (1.05; 1.02-1.08) or number of nonocular health conditions (1.12; 1.01-1.24) was significant. The total effect of visual impairment on death from suicide was elevated but not significant (1.64; 0.99-2.72). Conclusions Visual impairment may be associated with an increased risk of suicide through its effect on poor health. This suggests that improved treatment of visual impairment and factors causing poor health may potentially reduce suicide risk.
67 citations
TL;DR: In addition to the direct link between VI and mortality, the effects of VI on general health and disability contribute to an increased risk of death.
Abstract: PURPOSE. To estimate the direct effects of self-reported visual impairment (VI) on health, disability, and mortality and to estimate the indirect effects of VI on mortality through health and disability mediators. METHODS. The National Health Interview Survey (NHIS) is a population-based annual survey designed to be representative of the U.S. civilian noninstitutionalized population. The National Death Index of 135,581 NHIS adult participants, 18 years of age and older, from 1986 to 1996 provided the mortality linkage through 2002. A generalized linear structural equation model (GSEM) with latent variable was used to estimate the results of a system of equations with various outcomes. Standard errors and test statistics were corrected for weighting, clustering, and stratification. RESULTS. VI affects mortality, when direct adjustment was made for the covariates. Severe VI increases the hazard rate by a factor of 1.28 (95% CI: 1.07‐1.53) compared with no VI, and some VI increases the hazard by a factor of 1.13 (95% CI: 1.07‐1.20). VI also affects mortality indirectly through selfrated health and disability. The total effects (direct effects plus mediated effects) on the hazard of mortality of severe VI and some VI relative to no VI are hazard ratio (HR) 1.54 (95% CI: 1.28‐1.86) and HR 1.23 (95% CI: 1.16‐1.31), respectively. CONCLUSIONS. In addition to the direct link between VI and mortality, the effects of VI on general health and disability contribute to an increased risk of death. Ignoring the latter may lead to an underestimation of the substantive impact of VI on mortality. (Invest Ophthalmol Vis Sci. 2008;49:3318‐3323)
54 citations
TL;DR: This is the first report of an AT/RT presenting as an isolated third cranial nerve palsy caused by tumor arising from within the nerve, and despite aggressive chemotherapy, the patient died within 6 months of presentation.
Abstract: An otherwise healthy 6-week-old girl who presented with an isolated left third cranial nerve palsy underwent MRI that revealed an enhancing mass intrinsic to the left third cranial nerve. Rapid enlargement of the lesion over 1 month led to subtotal neurosurgical resection of an atypical teratoid/rhabdoid tumor (AT/RT), a rare, highly aggressive malignancy of infancy closely related histologically to medulloblastoma and primitive neuroectodermal tumor. Despite aggressive chemotherapy, the patient died within 6 months of presentation. This is the first report of an AT/RT presenting as an isolated third cranial nerve palsy caused by tumor arising from within the nerve.
12 citations