Thyroid hormone is essential for normal brain development including structures critical for visual processing. While chick and rodent models have demonstrated abnormal visual development following prenatal thyroid hor...Thyroid hormone is essential for normal brain development including structures critical for visual processing. While chick and rodent models have demonstrated abnormal visual development following prenatal thyroid hormone loss, comparable data do not exist in the human. To determine whether human infants with intrauterine and early postnatal thyroid hormone insufficiencies have compromised visual abilities, we investigated contrast sensitivity and visual acuity development in 13 infant offspring of women with hypothyroidism during pregnancy (HYPO), 16 preterm infants born between 32 and 35 weeks gestation, 12 infants with congenital hypothyroidism (CH), and 20 typically developing infants. All were assessed with the sweep visual evoked potential technique at 3, 4.5, and 6 months (corrected) age. Results showed significantly reduced contrast sensitivity but normal visual acuity in HYPO and CH groups relative to controls (p < 0.003 and p < 0.05 respectively). Stratification of the HYPO group into subgroups based on maternal TSH levels during the first half of pregnancy revealed lower contrast sensitivities for infants whose mothers’TSH values were above than below the median (p < 0.05). In the CH group, those with an absent thyroid gland and/or a newborn TSH value above 200 mIU/L had lower contrast sensitivities than did those with other etiologies or TSH levels below 100 mIU/L (p< 0.05). There were no significant effects involving the preterm group. These results indicate that thyroid hormone is important for human visual development.展开更多
Background: To investigate the effects of oral nimodipine on ocular hemodynamic parameters and color contrast sensitivity in patients with normal tension glaucoma (NTG). Methods: The study was performed in 14 consecut...Background: To investigate the effects of oral nimodipine on ocular hemodynamic parameters and color contrast sensitivity in patients with normal tension glaucoma (NTG). Methods: The study was performed in 14 consecutive NTG patients in a randomized placebo controlled double-masked cross-over design. The effects or oral nimodipine (60 mg) or placebo on ocular and systemic hemodynamic parameters and color contrast展开更多
To investigate image preferences after photodynamic therapy (PDT). Prospective, cross-sectional study. Seventeen patients with neovascular age-related macular degeneration were tested by color vision, contrast sensiti...To investigate image preferences after photodynamic therapy (PDT). Prospective, cross-sectional study. Seventeen patients with neovascular age-related macular degeneration were tested by color vision, contrast sensitivity, and near visual acuity (VA)-with positive images and negative images before, 1 week after, and 3 months after PDT. Before PDT, 13 patients (76% ) preferred positive images; the difference was not significant (P < .04). One week after PDT, 16 patients (94% ) preferred negative images. The average near VA improved to 27 letters on positive images and to32 letters on negative images (P < .00001). Three months after PDT, near VA declined to 19 letters on positive images and to 26 letters on negative images (P < . 000001). Color vision and contrast sensitivity remained constant during all examinations. Although PDT may not alter the neurosensory retina, it may affect intraretinal function by changing image preference.展开更多
Background: Late-onset Tay-Sachs disease (LOTS) is an adult-onset, auto somal recessive, progressive variant of GM2 gangliosidosis, characterized by inv olvement of the cerebellum and anterior horn cells. Abstract Obj...Background: Late-onset Tay-Sachs disease (LOTS) is an adult-onset, auto somal recessive, progressive variant of GM2 gangliosidosis, characterized by inv olvement of the cerebellum and anterior horn cells. Abstract Objective: To determine the range of visual and ocular motor abnormalities in LOTS, as a prelude to evaluati ng the effectiveness of novel therapies. Methods: Fourteen patients with biochem ically confirmed LOTS (8 men; age range 24 to 53 years; disease duration 5 to 30 years) and 10 age-matched control subjects were studied. Snellen visual acuit y, contrast sensitivity, color vision, stereopsis, and visual fields were measur ed, and optic fundi were photographed. Horizontal and vertical eye movements (se arch coil) were recorded, and saccades, pursuit, vestibulo-ocular reflex (VOR) , vergence, and optokinetic (OK) responses were measured. Results: All patients showed normal visual functions and optic fundi. The main eye movement abnormalit y concerned saccades, which were “ multistep,” consisting of a series of smal l saccades and larger movements that showed transient decelerations. Larger sacc ades ended earlier and more abruptly (greater peak deceleration) in LOTS patient s than in control subjects; these changes can be attributed to premature termina tion of the saccadic pulse. Smooth-pursuit and slow-phase OK gains were redu ced, but VOR, vergence, and gaze holding were normal. Conclusions: Patients with late-onset Tay-Sachs disease (LOTS) show characteristic abnormalities of sa ccades but normal afferent visual systems. Hypometria, transient decelerations, and premature termination of saccades suggest disruption of a “ latch circuit” that normally inhibits pontine omnipause neurons, permitting burst neurons to discharge until the eye movement is completed. These measurable abnormalities of saccades provide a means to evaluate the effects of novel treatments for LOTS.展开更多
文摘Thyroid hormone is essential for normal brain development including structures critical for visual processing. While chick and rodent models have demonstrated abnormal visual development following prenatal thyroid hormone loss, comparable data do not exist in the human. To determine whether human infants with intrauterine and early postnatal thyroid hormone insufficiencies have compromised visual abilities, we investigated contrast sensitivity and visual acuity development in 13 infant offspring of women with hypothyroidism during pregnancy (HYPO), 16 preterm infants born between 32 and 35 weeks gestation, 12 infants with congenital hypothyroidism (CH), and 20 typically developing infants. All were assessed with the sweep visual evoked potential technique at 3, 4.5, and 6 months (corrected) age. Results showed significantly reduced contrast sensitivity but normal visual acuity in HYPO and CH groups relative to controls (p < 0.003 and p < 0.05 respectively). Stratification of the HYPO group into subgroups based on maternal TSH levels during the first half of pregnancy revealed lower contrast sensitivities for infants whose mothers’TSH values were above than below the median (p < 0.05). In the CH group, those with an absent thyroid gland and/or a newborn TSH value above 200 mIU/L had lower contrast sensitivities than did those with other etiologies or TSH levels below 100 mIU/L (p< 0.05). There were no significant effects involving the preterm group. These results indicate that thyroid hormone is important for human visual development.
文摘Background: To investigate the effects of oral nimodipine on ocular hemodynamic parameters and color contrast sensitivity in patients with normal tension glaucoma (NTG). Methods: The study was performed in 14 consecutive NTG patients in a randomized placebo controlled double-masked cross-over design. The effects or oral nimodipine (60 mg) or placebo on ocular and systemic hemodynamic parameters and color contrast
文摘To investigate image preferences after photodynamic therapy (PDT). Prospective, cross-sectional study. Seventeen patients with neovascular age-related macular degeneration were tested by color vision, contrast sensitivity, and near visual acuity (VA)-with positive images and negative images before, 1 week after, and 3 months after PDT. Before PDT, 13 patients (76% ) preferred positive images; the difference was not significant (P < .04). One week after PDT, 16 patients (94% ) preferred negative images. The average near VA improved to 27 letters on positive images and to32 letters on negative images (P < .00001). Three months after PDT, near VA declined to 19 letters on positive images and to 26 letters on negative images (P < . 000001). Color vision and contrast sensitivity remained constant during all examinations. Although PDT may not alter the neurosensory retina, it may affect intraretinal function by changing image preference.
文摘Background: Late-onset Tay-Sachs disease (LOTS) is an adult-onset, auto somal recessive, progressive variant of GM2 gangliosidosis, characterized by inv olvement of the cerebellum and anterior horn cells. Abstract Objective: To determine the range of visual and ocular motor abnormalities in LOTS, as a prelude to evaluati ng the effectiveness of novel therapies. Methods: Fourteen patients with biochem ically confirmed LOTS (8 men; age range 24 to 53 years; disease duration 5 to 30 years) and 10 age-matched control subjects were studied. Snellen visual acuit y, contrast sensitivity, color vision, stereopsis, and visual fields were measur ed, and optic fundi were photographed. Horizontal and vertical eye movements (se arch coil) were recorded, and saccades, pursuit, vestibulo-ocular reflex (VOR) , vergence, and optokinetic (OK) responses were measured. Results: All patients showed normal visual functions and optic fundi. The main eye movement abnormalit y concerned saccades, which were “ multistep,” consisting of a series of smal l saccades and larger movements that showed transient decelerations. Larger sacc ades ended earlier and more abruptly (greater peak deceleration) in LOTS patient s than in control subjects; these changes can be attributed to premature termina tion of the saccadic pulse. Smooth-pursuit and slow-phase OK gains were redu ced, but VOR, vergence, and gaze holding were normal. Conclusions: Patients with late-onset Tay-Sachs disease (LOTS) show characteristic abnormalities of sa ccades but normal afferent visual systems. Hypometria, transient decelerations, and premature termination of saccades suggest disruption of a “ latch circuit” that normally inhibits pontine omnipause neurons, permitting burst neurons to discharge until the eye movement is completed. These measurable abnormalities of saccades provide a means to evaluate the effects of novel treatments for LOTS.
