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Biomedical subjects

J M Tielsch

Publications and source records attributed to J M Tielsch.

At least 19 recordsLinked to original sources

Measurement of blood loss at childbirth and postpartum.

OBJECTIVE: To accurately measure blood loss during childbirth in a developing country. METHOD: The alkaline hematin technique was used to quantify blood lost during delivery and 24 h postpartum in 158 women in Pemba Island, Zanzibar. RESULT: Women were found to lose less blood during childbirth and 24 h postpartum than previously reported. Compared with laboratory values, nurse-midwives approximated blood loss accurately (mean difference, i.e., mean underestimation by nurse-midwives, 4.90 mL); however, their imprecision was greater for higher laboratory values. CONCLUSION: This study may prompt further investigation, as no comparable data exist for developing countries where maternal mortality is high and severe anemia prevalent.

Adolescent↗

Relationship between the surrogate anthropometric measures, foot length and chest circumference and birth weight among newborns of Sarlahi, Nepal.

BACKGROUND: Classification of infants into low birth weight (LBW, <2500 g) or very low birth weight (VLBW, <2000 g) categories is a crucial step in targeting interventions to high-risk infants. OBJECTIVE: To compare the validity of chest circumference and foot length as surrogate anthropometric measures for the identification of LBW and VLBW infants. SUBJECTS AND SETTING: Newborn infants (n=1640) born between March and June 2004 in 30 Village Development Committees of Sarlahi district, Nepal. DESIGN: Chest circumference, foot length and weight (SECA 727, precise to 2 g) of newborns were measured within 72 h after birth. The sensitivity, specificity and predictive values for a range of cutoff points of the anthropometric measures were estimated using the digital scale measurements as the gold standard. RESULTS: Among LBW infants (469/1640, 28.6%), chest circumference measures <30.3 cm were 91% sensitive and 83% specific. Similar levels of sensitivity for foot length were achieved only with considerable loss of specificity (<45%). Foot length measurements <6.9 cm were 88% sensitive and 86% specific for the identification of VLBW infants. CONCLUSION: Chest circumference was superior to foot length in classification of infants into birth weight categories. For the identification of VLBW infants, foot length performed well, and may be preferable to chest circumference, as the former measure does not require removal of infant swaddling clothes. In the absence of more precise direct measures of birth weight, chest circumference is recommended over foot length for the identification of LBW infants.

Anthropometry↗

A low cost, colour coded, hand held spring scale accurately categorises birth weight in low resource settings.

AIMS: To determine the accuracy of a low cost, spring calibrated, hand held scale in classifying newborns into three weight categories (> or =2500 g, 2000-2499 g, <2000 g). METHODS: The test device was compared to a gold standard digital baby scale with precision to 2 g. In Sarlahi district, Nepal, 1890 newborns were eligible for the study. Measurements were collected for both the test device and the digital scale from 1820 (96.3%) newborns. RESULTS: The overall low birth weight (LBW) prevalence rate for the gold standard digital scale was 28.1% (511/1820). Sensitivity (93.7%) and specificity (97.6%) of the test device was high compared to LBW classifications based on digital weight measurements. Classification of infants into the <2000 g category was 5.0% and 4.7% for the gold standard and test device, respectively. Sensitivity and specificity of the test device in identifying infants <2000 g was 87.8% and 99.6%, respectively. Positive predictive values were high (>91%) for both weight categories CONCLUSIONS: This low cost, simple-to-use device classified infants into weight categories with a high degree of consistency and accuracy that exceeds that of surrogate measures. This new device is useful for identifying and targeting life saving interventions for LBW, high risk infants in settings where infants are born in the home and conventional weighing scales are unavailable.

Birth Weight↗

Epidemiology of anemia among 4- to 17-month-old children living in south central Nepal.

OBJECTIVE: To describe the distribution of hemoglobin and prevalence of anemia in Nepali children living in the Terai region by potential risk factors for deficiency. DESIGN: This was a cross-sectional, community-based study of baseline characteristics of children enrolled in a randomized, placebo-controlled clinical trial between January and March 2002. Participants were weighed and measured and had their blood drawn. Their mothers contributed demographic, morbidity, and feeding data. SUBJECTS: There were 569 4- to 17-month-old children. Statistical models were based on 490 children. RESULTS: Anemia was prevalent: 58% of the children had a hemoglobin <105 g/l. Iron-deficiency anemia (anemia with erythrocyte protoporphyrin (EP) > or =90 micromol/mol heme) was present in 43% of the children. Severe anemia was rare: less than 2% of the children had a hemoglobin <70 g/l. The mean (s.d.) hemoglobin concentration was 101 (12.5) g/l. Stunting and wasting were prevalent: 30.8% were stunted (length-for-age Z-score <-2) and 18.1% were wasted (weight-for-length Z-score <-2). Bivariate analyses revealed that age, caste, socioeconomic status, dietary diversity, stunting, and underweight were associated with hemoglobin concentration and/or anemia. In multivariate models with and without EP, age and caste were found to be strong predictors of both hemoglobin concentration and anemia. CONCLUSIONS: Anemia and iron deficiency increased strongly with age and low-caste status among the study children. The data reveal the importance of targeting interventions to children in the first year of life before they become anemic and iron deficient.

Age Factors↗

Development of clinical sign based algorithms for community based assessment of omphalitis.

BACKGROUND: In developing countries, newborn omphalitis contributes significantly to morbidity and mortality. Community based identification and management of omphalitis will require standardised clinical sign based definitions. OBJECTIVE: To identify optimal sign based algorithms to define omphalitis in the community and to evaluate the reliability and validity of cord assessments by non-specialist health workers for clinical signs of omphalitis. DESIGN: Within a trial of the impact of topical antiseptics on umbilical cord infection in rural Nepal, digital images of the umbilical cord were collected. Workers responsible for in-home examinations of the umbilical cord evaluated the images for signs of infection (pus, redness, swelling). Intraworker and interworker agreement was evaluated, and sensitivity and specificity compared with a physician generated gold standard ranking were estimated. RESULTS: Sensitivity and specificity of worker evaluations were high for pus (90% and 96% respectively) and moderate for redness (57% and 95% respectively). Swelling was the least reliably identified sign. Measures of observer agreement were similar to that previously recorded between experts evaluating subjective skin conditions. A composite definition for omphalitis that combined pus and redness without regard to swelling was the most sensitive and specific. CONCLUSIONS: Two sign based algorithms for defining omphalitis are recommended for use in the community. Focusing on redness extending to the skin around the base of the stump will identify cases of moderate and high severity. Requiring both the presence of pus and redness will result in a definition with very high specificity and moderate to high sensitivity.

Algorithms↗

Risk factors for age related cataract in a rural population of southern India: the Aravind Comprehensive Eye Study.

AIM: To determine risk factors for lens opacities and age related cataract in an older rural population of southern India. METHODS: A cross sectional population based study of 5150 people aged 40 years and above from 50 clusters from three districts in southern India. The lens was graded and classified after dilation using LOCS III system at the slit lamp for cataract. Definite cataract was defined as nuclear opalescence >/=3.0 and/or cortical cataract >/=3.0 and/or PSC >/=2.0. RESULTS: Definite cataracts were found in 2449 (47.5%) of 5150 subjects and the prevalence of cataract increased with age. The age adjusted prevalence of cataract was significantly lower in males (p = 0.0002). Demographic risk factors-increasing age and illiteracy-were common for the three subtypes of cataract; females were more likely to have cortical cataracts and nuclear cataracts. Additionally, nuclear cataracts were associated with moderate smoking (OR:1.28, 95% CI:1.01 to 1.64), lean body mass indices (OR: 1.37, 95% CI: 1.17 to 1.59) and higher waist to hip ratios (OR: 0.67, 95% CI: 0.54 to 0.82); cortical cataracts with hypertension (OR: 1.39 95% CI:1.11 to 1.72), pseudoexfoliation (OR:1.53,95% CI:1.17 to 2.01), and moderate to heavy smoking; and posterior subcapsular cataracts with diabetes (OR:1.55, 95% CI:1.12 to 2.15), lean body mass (OR:1.32, 95% CI:1.11 to 1.57), and high waist to hip ratios (OR: 0.77, 95% CI: 0.62 to 0.94). CONCLUSIONS: Risk factors for age related cataract in this population do not appear to be different from those reported in other populations. Further studies are required to identify the reason for the high prevalence of age related cataract and to understand better the role of each risk factor for cataractogenesis in this population.

Adult↗

Nasopharyngeal carriage of resistant pneumococci in young South Indian infants.

Streptococcus pneumoniae is the leading bacterial cause of life-threatening infections in infants. Although antibiotic resistance affects management of pneumococcal infections, few data on patterns of resistance are available for India. We examined nasopharyngeal carriage of antibiotic-resistant pneumococci in 464 South Indian infants between 2 and 6 months. Newly acquired serotypes were screened for susceptibility to cotrimoxazole, erythromycin and penicillin using disk diffusion. Cumulative prevalence of pneumococcal carriage rose from 53.9% at 2 months to 70.2% at 6 months. The prevalence of strains that were not susceptible to penicillin, cotrimoxazole and erythromycin was 34, 81.1 and 37.2%, respectively. Carriage of erythromycin non-susceptible strains declined significantly between ages 4 months and 6 months (44.1 vs. 10.7%). More than 87% of the isolates screened were non-susceptible to > or = 1 antibiotic. Serogroups/types that were most frequently non-susceptible to 1 or more antibiotics were 6, 9, 14, 19 and 23. Less than 1% of the isolates were multi-drug resistant. Widespread use of antibiotics in South India has resulted in S. pneumoniae becoming non-susceptible to some commonly used antibiotics. Monitoring trends in antibiotic susceptibility and making antibiotics available only through prescription from a health care worker may slow the spread of resistant pneumococci and improve management of pneumococcal infections in South India.

Carrier State↗

VF-14 item specific responses in patients undergoing first eye cataract surgery: can the length of the VF-14 be reduced?

AIMS: To report the item specific responses of the VF-14 in a population of patients undergoing cataract surgery in their first eye and to determine whether or not the VF-14 can be reduced without compromising its performance as an index of cataract related visual impairment. METHODS: The item specific responses to the VF-14 were analysed before (771 patients) and 4 months after (552 patients) cataract surgery in one eye to determine if the VF-14 index can be reduced without compromising its performance. Patients studied were selected from a cross sectional longitudinal study of patients undergoing cataract surgery in 72 ophthalmologist's offices located in three metropolitan regions of the United States. RESULTS: Pairwise correlations between items in the VF-14 were all less than 0.6, indicating that no items could be removed solely on the basis of redundancy. 10 items correlated moderately with change in trouble, and 11 correlated moderately with change in satisfaction (r >0.15) at 4 months after cataract extraction. Eleven items demonstrated an effect size >0.4 at 4 months. These 11 items were either important for detecting cataract related functional disability or for quantifying the extent to which cataract impaired function. Additionally, 11 items were needed to detect adequately individuals with functional impairment. Three items (recognising people, cooking, and reading large print) were less responsive to cataract extraction and were more strongly associated with ocular comorbidities. CONCLUSIONS: While previous reports indicate that the VF-14 can be significantly shortened, our analysis only justifies removing three items. While the resulting VF-11 has properties similar to the VF-14, the limited time savings do not justify altering this already validated instrument.

Aged↗

Retinal microvascular abnormalities and blood pressure in older people: the Cardiovascular Health Study.

AIM: To examine the relation between blood pressure and retinal microvascular abnormalities in older people. METHODS: The Cardiovascular Health Study is a prospective cohort study conducted in four US communities initiated in 1989 to 1990. Blood pressure was measured according to standardised protocols at each examination. During the 1997-8 examination, retinal photographs were taken of 2405 people aged 69-97 years (2056 without diabetes and 349 with diabetes). Signs of focal microvascular abnormalities (focal arteriolar narrowing, arteriovenous nicking, and retinopathy) were evaluated from photographs according to standardised methods. To quantify generalised arteriolar narrowing, the photographs were digitised and diameters of individual arterioles were measured and summarised. RESULTS: In non-diabetic people, elevated concurrent blood pressure taken at the time of retinal photography was strongly associated with presence of all retinal microvascular lesions. The multivariable adjusted odds ratios, comparing the highest to lowest quintile of concurrent systolic blood pressure, were 4.0 (95% confidence intervals (CI): 2.4 to 6.9, p test of trend<0.001) for focal arteriolar narrowing, 2.9 (95% CI: 1.6 to 5.3, p<0.001) for arteriovenous nicking, 2.8 (95% CI: 1.5 to 5.2, p<0.001) for retinopathy, and 2.1 (95% CI: 1.4 to 3.1, p<0.001) for generalised arteriolar narrowing. Generalised arteriolar narrowing and possibly arteriovenous nicking were also significantly associated with past blood pressure measured up to 8 years before retinal photography, even after adjustment for concurrent blood pressure. These associations were somewhat weaker in people with diabetes. CONCLUSIONS: Retinal microvascular abnormalities are related to elevated concurrent blood pressure in older people. Additionally, generalised retinal arteriolar narrowing and possibly arteriovenous nicking are related to previously elevated blood pressure, independent of concurrent blood pressure. These data suggest that retinal microvascular changes reflect severity and duration of hypertension.

Aged↗

Effects of iron supplementation and anthelmintic treatment on motor and language development of preschool children in Zanzibar: double blind, placebo controlled study.

OBJECTIVE: To measure the effects of iron supplementation and anthelmintic treatment on iron status, anaemia, growth, morbidity, and development of children aged 6-59 months. DESIGN: Double blind, placebo controlled randomised factorial trial of iron supplementation and anthelmintic treatment. SETTING: Community in Pemba Island, Zanzibar. PARTICIPANTS: 614 preschool children aged 6-59 months. MAIN OUTCOME MEASURES: Development of language and motor skills assessed by parental interview before and after treatment in age appropriate subgroups. RESULTS: Before intervention, anaemia was prevalent and severe, and geohelminth infections were prevalent and light-Plasmodium falciparum infection was nearly universal. Iron supplementation significantly improved iron status, but not haemoglobin status. Iron supplementation improved language development by 0.8 (95% confidence interval 0.2 to 1.4) points on the 20 point scale. Iron supplementation also improved motor development, but this effect was modified by baseline haemoglobin concentrations (P=0.015 for interaction term) and was apparent only in children with baseline haemoglobin concentrations <90 g/l. In children with a baseline haemoglobin concentration of 68 g/l (one standard deviation below the mean value), iron treatment increased scores by 1.1 (0.1 to 2.1) points on the 18 point motor scale. Mebendazole significantly reduced the number and severity of infections caused by Ascaris lumbricoides and Trichuris trichiura, but not by hookworms. Mebendazole increased development scores by 0.4 (-0.3 to 1.1) points on the motor scale and 0.3 (-0.3 to 0.9) points on the language scale. CONCLUSIONS: Iron supplementation improved motor and language development of preschool children in rural Africa. The effects of iron on motor development were limited to children with more severe anaemia (baseline haemoglobin concentration <90 g/l). Mebendazole had a positive effect on motor and language development, but this was not statistically significant.

Anemia, Iron-Deficiency↗

Adverse intraoperative medical events and their association with anesthesia management strategies in cataract surgery.

OBJECTIVE: To compare adverse medical events by different anesthesia strategies for cataract surgery. DESIGN: Prospective cohort study. PARTICIPANTS: Patients 50 years of age and older undergoing 19,250 cataract surgeries at nine centers in the United States and Canada between June 1995 and June 1997. INTERVENTION: Local anesthesia applied topically or by injection, with or without oral and intravenous sedatives, opioid analgesia, hypnotics, and diphenhydramine (Benadryl). MAIN OUTCOME MEASURES: Intraoperative and postoperative adverse medical events. RESULTS: Twenty-six percent of surgeries were performed with topical anesthesia and the remainder with injection anesthesia. There was no increase in deaths and hospitalizations associated with any specific anesthesia strategy. No statistically significant difference was observed in the prevalence of intraoperative events between topical and injection anesthesia without intravenous sedatives (0.13% and 0.78%, respectively). The use of intravenous sedatives was associated with a significant increase in adverse events for topical (1.20%) and injection anesthesia (1.18%), relative to topical anesthesia without intravenous sedation. The use of short-acting hypnotic agents with injection anesthesia was also associated with a significant increase in adverse events when used alone (1.40%) or in combination with opiates (1.75%), sedatives (2.65%), and with the combination of opiates and sedatives (4.04%). These differences remained after adjusting for age, gender, duration of surgery, and American Society of Anesthesiologists risk class. CONCLUSIONS: Adjuvant intravenous anesthetic agents used to decrease pain and alleviate anxiety are associated with increases in medical events. However, cataract surgery is a safe procedure with a low absolute risk of medical complications with either topical or injection anesthesia. Clinicians should weigh the risks and benefits of their use for individual patients.

Adjuvants, Anesthesia↗

Vitamin A supplementation at birth delays pneumococcal colonization in South Indian infants.

Nasopharyngeal colonization is a risk factor for pneumococcal disease, a leading cause of complications and death in infants. We assessed the impact of vitamin A supplementation in reducing pneumococcal colonization in infants from an area with endemic vitamin A deficiency. We recruited 464 2-mo-old infants from a rural area in South India. Infants were randomly assigned to receive two 7000-microg retinol equivalent doses of vitamin A (n = 239) or placebo (n = 225) orally at birth, and nasopharyngeal specimens were collected at ages 2, 4 and 6 mo. We studied the effect of vitamin A on culture-confirmed pneumococcal colonization and on the distribution of pneumococcal serotypes. Analyses were conducted by intention-to-treat. The risk of colonization among infants aged 4 mo who were not colonized by age 2 mo was significantly reduced in the vitamin A group compared with the placebo group [odds ratio 0.51 (0.28, 0.92), P = 0.02). The odds of colonization were 27% lower in the treatment group than in the placebo group [odds ratio 0.73 (0.48, 1.1), P = 0.13]. No differences were detected in the prevalence of invasive serotypes. The risk of colonization with penicillin-resistant isolates was 74% lower in the vitamin A group than in the placebo group at 2 mo of age. However, the prevalence of penicillin-resistant isolates was only 4%. Neonatal vitamin A supplementation may play a role in lowering morbidity rates associated with pneumococcal disease by delaying the age at which colonization occurs.

Dietary Supplements↗

Pneumococcal nasopharyngeal colonization in young South Indian infants.

BACKGROUND: Streptococcus pneumoniae is the most frequent bacterial cause of morbidity and mortality in young children. Bacteria carried in the nasopharynx of healthy children reflect the prevalent strains circulating in the community. METHODS: We recruited 464 newborns from a rural area in South India with endemic vitamin A deficiency. Nasopharyngeal specimens were collected from each infant at ages 2, 4 and 6 months. RESULTS: Fifty-four percent of study infants were colonized by age 2 months, with 64.1 and 70.2% carriage prevalence at ages 4 and 6 months, respectively. The odds of carriage at 2 months were significantly increased in female infants, infants living in a household in which 20 or more cigarettes were smoked each day, infants whose mothers had less than 1 year of schooling and infants fed colostrum. At age 4 months infants having 2 or more siblings <5 years of age were at significantly increased risk of carriage. At age 6 months none of the potential risk factors examined achieved statistical significance, but maternal night blindness increased the risk of colonization 3-fold. The odds of carrying a PncCRM197 vaccine serotype were increased among infants born to mothers who experienced night blindness during pregnancy. The most prevalent serogroups/types during the first 6 months of life were 6, 9, 10, 11, 14, 15, 19, 23 and 33, accounting for 76.7% of all serotyped isolates. CONCLUSIONS: South Indian infants experience high rates of pneumococcal carriage during the first 6 months of life, which may partially explain their increased risk for pneumonia.

Age Factors↗

Variations in ocular biometry in an adult Chinese population in Singapore: the Tanjong Pagar Survey.

PURPOSE: To describe the variation in ocular biometry in adult Chinese individuals in Singapore. METHODS: This study was a population-based, cross-sectional survey of adult Chinese persons aged 40 to 81 years residing in Tanjong Pagar district, Singapore. Axial ocular dimensions, including axial length (AL), anterior chamber depth (ACD), lens thickness (LT), and vitreous chamber depth (VCD) were measured using an A-scan ultrasound device. Corneal curvature (CC) and noncycloplegic refraction were measured with an autorefractor, with refraction further refined subjectively. Lens nuclear opacity (NO) was graded clinically using the modified Lens Opacity Classification System III (LOCS III) score. RESULTS: A total of 1717 subjects were eligible for the survey, of whom 1232 (71.8%) participated. Biometric and refraction data were available for 1004 (58.5%) phakic subjects. The AL, ACD, LT, VCD, CC, and LOCS III scores were 23.23 +/- 1.17 mm, 2.90 +/- 0.44 mm, 4.75 +/- 0.47 mm, 15.58 +/- 1.11 mm, 7.65 +/- 0.27 mm, and 3.2 +/- 0.9 (mean +/- SD), respectively. On average, people aged 40 to 49 years, when compared with those 70 to 81 years, had longer ALs (mean difference, +0.58 mm), deeper ACDs (+0.52 mm), longer VCDs (+0.72 mm), but thinner lenses (-0.70 mm) and less severe NO (-1.7 LOCS III score). CCs did not vary significantly with age. After controlling for age, women had shorter ALs and VCDs, shallower ACDs, but thicker lenses and steeper CCs than men. The variation in noncycloplegic refraction with age was nonlinear. Among people aged 40 to 59 years, a higher prevalence of hyperopia was seen in older compared with younger persons (on average, a difference of +1.3 D for every 10-year difference in age, P: < 0.001), explained principally by shorter AL (and VCD) in older persons. Among those 60 to 81 years, this pattern was not obvious (a difference of -0.03 D for every 10-year difference in age, P: = 0.12), as NO became an additional determinant of refraction, with greater degrees of NO in older person's driving refraction in the "minus" direction. CONCLUSIONS: Ocular dimensions vary with age and gender in adult Chinese persons in Singapore. The variation in noncycloplegic refraction in people 40 years and older may be explained by differences in axial lengths (principally vitreous chamber depths) between older and younger persons and, from 60 years onwards, differences in lens nuclear opacification as well.

Adult↗

The value of routine preoperative medical testing before cataract surgery. Study of Medical Testing for Cataract Surgery.

BACKGROUND: Routine preoperative medical testing is commonly performed in patients scheduled to undergo cataract surgery, although the value of such testing is uncertain. We performed a study to determine whether routine testing helps reduce the incidence of intraoperative and postoperative medical complications. METHODS: We randomly assigned 19,557 elective cataract operations in 18,189 patients at nine centers to be preceded or not preceded by a standard battery of medical tests (electrocardiography, complete blood count, and measurement of serum levels of electrolytes, urea nitrogen, creatinine, and glucose), in addition to a history taking and physical examination. Adverse medical events and interventions on the day of surgery and during the seven days after surgery were recorded. RESULTS: Medical outcomes were assessed in 9408 patients who underwent 9626 cataract operations that were not preceded by routine testing and in 9411 patients who underwent 9624 operations that were preceded by routine testing. The most frequent medical events in both groups were treatment for hypertension and arrhythmia (principally bradycardia). The overall rate of complications (intraoperative and postoperative events combined) was the same in the two groups (31.3 events per 1000 operations). There were also no significant differences between the no-testing group and the testing group in the rates of intraoperative events (19.2 and 19.7, respectively, per 1000 operations) and postoperative events (12.6 and 12.1 per 1000 operations). Analyses stratified according to age, sex, race, physical status (according to the American Society of Anesthesiologists classification), and medical history revealed no benefit of routine testing. CONCLUSIONS: Routine medical testing before cataract surgery does not measurably increase the safety of the surgery.

Aged↗

Ocular trauma in the United States Army: hospitalization records from 1985 through 1994.

PURPOSE: To determine the incidence of hospitalized ocular injury in the United States Army and evaluate specific types and external causes of these injuries. METHODS: A US Army database that captured all hospital discharge records for Army personnel admitted to military and civilian hospitals was used to determine incident episodes of ocular injury requiring hospitalization from 1985 through 1994. Denominator data were available from the US Army. RESULTS: The average annual incidence of hospitalization for a principal or secondary diagnosis of ocular trauma (total hospitalized ocular injury) was 77.1 per 100,000 persons (95% confidence interval, 75.1-79.2). There was a 38% decline in the rate of total hospitalized ocular injury during this 10-year period. Men had twice the rates of women over all age groups. The highest rate occurred in the 17- to 19-year age group, with rates of 220.7 and 123.4 per 100,000 in men and women, respectively. Whites had a higher rate than blacks and nonwhites-nonblacks. Almost a third of the injuries were contusions of the eye and adnexa. Among men, the leading causes were machinery or tools (21%), fights (18%), transport accidents (18%), and sports and training (11%). Only 7% were related to weaponry or war, and of these, 90% were from nonbattle activities. CONCLUSION: The type and cause of injury suggest that preventive measures may be effective in decreasing the incidence of ocular trauma requiring hospitalization in US Army personnel.

Adolescent↗

Screening for amblyopia in preverbal children with photoscreening photographs: II. Sensitivity and specificity of the MTI photoscreener.

OBJECTIVE: To determine the sensitivity and specificity of vision screening using the Medical Technology and Innovations (MTI), Inc., PhotoScreener. DESIGN: Cross-sectional study. PARTICIPANTS AND TESTING: Three hundred ninety-two children less than 4 years of age received a complete ophthalmologic examination and were photographed using the MTI PhotoScreener. One hundred three children had normal examinations, and the remaining 284 children had conditions of interest for pediatric screening: ptosis, media opacity, refractive error, or strabismus. Five children were excluded. MAIN OUTCOME MEASURES: The grading of the photographs by the manufacturer's representative was compared with the results of the ophthalmologic examinations. Sensitivity and specificity of vision screening were determined. RESULTS: The analysis of all informative photographs resulted in a sensitivity of 65% and a specificity of 87%. The sensitivity of detection for children with some forms of strabismus was high, up to 95% for esotropia of 10Delta or more. Sensitivities for the detection of ptosis, media opacity, and refractive error were poor in patients where strabismus was not also present. CONCLUSIONS: The MTI PhotoScreener may play a role in preverbal vision screening; identification of two of three children with amblyopiogenic factors before age 4 would be an exciting advance in public health. However, improvement in the ability to identify children with media opacity and refractive error is necessary. Improvements may be possible with modifications of the examination failure and photograph grading criteria.

Amblyopia↗

Screening for amblyopia in preverbal children with photoscreening photographs. III. improved grading criteria for hyperopia.

OBJECTIVE: To examine the ability of the Medical Technology and Innovations (MTI), Inc., Photoscreener (Cedar Falls, IA) to detect hyperopia and to improve the photograph grading criteria to screen for amblyopiogenic levels of hyperopia. DESIGN: Cross-sectional study and reanalysis. PARTICIPANTS AND TESTING: In previous work, 392 participants received a complete ophthalmologic examination and were photographed using the MTI Photoscreener. For this study, all 209 participants with normal examination findings (65 children) or hyperopia without anisometropia (144 children) were selected. The data were reanalyzed using modified photograph grading and ophthalmologic examination failure criteria. Potential reasons for why many children with hyperopia passed photoscreening were explored. MAIN OUTCOME MEASURES: We determined whether a study participant would pass or fail screening with a given photograph grading and ophthalmologic examination failure criteria. RESULTS: Most children with hyperopia of +2.00 to +3.50 diopters (D) passed screening with the MTI instrument, in most cases because their photographs lacked bright crescents. When bright crescents in at least two of the four possible meridians were the grading guideline for screening failure and the pediatric ophthalmologists' consensus hyperopia failure criteria (> +3.50 D) were adopted, the sensitivity for hyperopia detection was 100% and the specificity was 88%. Identical results were obtained using the American Academy of Ophthalmology Preferred Practice Pattern hyperopia failure criteria (>/= +4.50 D). CONCLUSIONS: The MTI photograph grading guidelines can be simplified, and the ophthalmologic examination failure criteria for hyperopia can be improved. The presence of a bright crescent in the lower or the left pupillary margin indicate hyperopia in an amblyopiogenic range (> +3.50 D).

Amblyopia↗