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To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.ajo.2008.11.021 Byline: Qing Lu (a), Yuanyuan Zheng (b), Baochen Sun (b), Tongtong Cui (b), Nathan Congdon (c), Ailian Hu (b), Jianhua Chen (d), Jiliang Shi (e) Abstract: To evaluate the prevalence and causes of visual impairment among Chinese children aged 3 to 6 years in Beijing. Author Affiliation: (a) Shenyang He Eye Hospital, Shenyang, China (b) Beijing Institute of Ophthalmology, Beijing Tongren Hospital, Capital Medical University, Beijing, China (c) Chinese University of Hong Kong, Department of Ophthalmology and Vision Science, Hong Kong, China (d) Beijing Hospital of Gerontology, Beijing, China (e) Beijing Disabled Persons' Federation, Beijing, China Article History: Accepted 24 November 2008

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.ajo.2005.12.007 Byline: Nathan G. Congdon (a), Aimee T. Broman (a), Karen Bandeen-Roche (b), Davinder Grover (a), Harry A. Quigley (a) Abstract: We sought to measure the impact of central corneal thickness (CCT), a possible risk factor for glaucoma damage, and corneal hysteresis, a proposed measure of corneal resistance to deformation, on various indicators of glaucoma damage. Author Affiliation: (a) Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland (b) Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland Article History: Accepted 8 December 2005

Two hundred seven vitamin A-deficient southern Indian children aged 1-7 y (mean age: 56.9 mo) underwent testing of dark-adapted visual and pupillary thresholds in their village setting according to a previously reported protocol. One hundred thirty (62.8%) of the children also underwent serum retinol testing, and 178 86.0% participated in a randomized, placebo-controlled vitamin A dosing trial with pre- and postdose testing of dark-adaptation threshold. Most subjects (184 of 207, 88.9%) were able to complete pupillary testing, an objective sign requiring minimal cooperation, including a high proportion of the youngest children (72.2% of subjects aged 2 y). The proportion of children completing visual threshold testing, which requires greater understanding and cooperation, was significantly smaller than that able to complete pupillary testing (131 of 207, 63.3%; P [is less than] 0.0001, chi square). At baseline (predosing), the mean serum retinol concentration declined in linear fashion with a higher pupillary threshold (0.73 [Mu]mol/L with a score [is less than or equal to] 4;0.47 [Mu]mol/L with a score [is greater than or equal to] 8; P [is less than] 0.01). The mean pupillary threshold for these highly vitamin A-deficient Indian children (-0.622 log cd/[m.sup.2]) was significantly higher than that for 136 more moderately deficient Indonesian children (-0.985 log cd/[m.sup.2]; P [is less than] 0.001, two-sample t test) and 56 normal American children (-1.335 log cd/[m.sup.2]; P [is less than] 0.0001, two-sample t test). The improvement in pupillary dark-adaptation testing was not significant for children receiving vitamin A or placebo, though there was a nonsignificant trend toward greater improvement in children receiving vitamin A (P = 0.2, two-sample t test). Pupillary threshold testing represents a new, noninvasive, practical, and seemingly valid approach to assessing the vitamin A status of a moderately to severely deficient preschool population.

A prototype scotopic sensitivity machine was used to evaluate pupillary and visual thresholds for 295 Indonesian children aged 1-5 y, most of whom were initially vitamin A-deficient. Subjects were tested 6 and 9 mo after receiving a high dose of vitamin A. A group of 136 older children was tested at 6 mo after dosing; all subjects underwent testing at 9 mo. After testing at 9 mo, children randomly received either a second high dose of vitamin A or placebo and were tested a final time 2 wk later. Children with abnormal pupillary thresholds had significantly higher relative dose responses (RDRs) (P < 0.01) and significantly lower serum retinol values (P = 0.05) than did normal children. The mean pupillary threshold rose (eg, retinal sensitivity fell) as vitamin A status deteriorated between 6 and 9 mo after initial dosing, and was significantly different from a group of normal American children tested previously (P < 0.001). After placebo-controlled dosing, the decline in pupillary and visual thresholds (rise in retinal sensitivity) was significant for children receiving vitamin A but not for children receiving placebo. Am J Clin Nutr 1995;61:1076-82.

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.ajo.2006.11.051 Byline: Ningli Wang (a), Bingsong Wang (a), Gaoshou Zhai (b), Kun Lei (a), Lan Wang (a), Nathan Congdon (c) Abstract: To describe and evaluate a new method for measuring anterior chamber volume (ACV). Author Affiliation: (a) Tongren Ophthalmic Center, Beijing Tongren Hospital, Capital University of Medical Sciences, Beijing, China (b) School of Computer and Information Technology, Beijing Jiaotong University, Beijing, China (c) Department of Ophthalmology and Visual Science, Hong Kong Eye Hospital, Chinese University of Hong Kong, Hong Kong. Article History: Accepted 22 November 2006

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.ajo.2006.11.036 Byline: David S. Friedman, Henry D. Jampel, Nathan G. Congdon, Rhonda Miller, Harry A. Quigley Abstract: To assess the accuracy of Travatan Dosing Aid recordings. Author Affiliation: Glaucoma Division of the Wilmer Eye Institute, Johns Hopkins University, Baltimore, Maryland. Article History: Accepted 3 November 2006

Byline: Nathan. Congdon, Mingguang. He, Yingfeng. Zheng Diabetic retinopathy (DR), a major microvascular complication of diabetes, has a significant impact on the world's health systems. Globally, the number of people [...]

Byline: Rita. Gangwani, David. Liu, Nathan. Congdon, Philip. Lam, Vincent. Lee, Nancy. Yuen, Dennis. Lam We evaluated the effectiveness of diode laser trans-scleral cyclophotocoagulation (TSCPC) on intraocular pressure (IOP) in [...]

Background: Impaired dark adaptation occurs commonly in vitamin A deficiency. Objective: We sought to examine the responsiveness of dark-adaptation threshold to vitamin A and [Beta]-carotene supplementation in Nepali women. Design: The dark-adapted pupillary response was tested in 298 pregnant women aged 15-45 y in a placebo-controlled trial of vitamin A and [Beta]-carotene; 131 of these women were also tested at 3 mo post-partum. Results were compared with those for 100 nonpregnant US women of similar age. The amount of light required for pupillary constriction was recorded after bleaching and dark adaptation. Results: Pregnant women receiving vitamin A had better dark-adaptation thresholds (-1.24 log cd/[m.sup.2]) than did those receiving placebo (-1.11 log cd/[m.sup.2]; P = 0.03) or [Beta]-carotene (-1.13 log cd/[m.sup.2]; P = 0.05) (t tests with Bonferroni correction). Dark-adaptation threshold was associated with serum retinol concentration in pregnant women receiving placebo (P = 0.001) and in those receiving [Beta]-carotene (P = 0.003) but not in those receiving vitamin A. Among women receiving placebo, mean dark-adaptation thresholds were better during the first trimester (-1.23 log cd/[m.sup.2]) than during the second and third trimesters (-1.03 log cd/[m.sup.2]; P = 0.02, t test). The mean threshold of nonpregnant US women (-1.35 log cd/[m.sup.2]) was better than that of all 3 Nepali groups (P [is less than] 0.001, t test, for all 3 groups). Conclusions: During pregnancy, pupillary dark adaptation was strongly associated with serum retinol concentration and improved significantly in response to vitamin A supplementation. This noninvasive testing technique is a valid indicator of population vitamin A status in women of reproductive age. Am J Clin Nutr 2000;72:1004-9. KEY WORDS Vitamin A, [Beta]-carotene, night blindness, pregnancy, lactation, pupil, dark adaptation, dark vision, night vision, Nepal, pregnant women, postpartum women