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At least 649 records · Page 36Linked to original sources

PubMed2001

Errors leading to unexpected pseudophakic ametropia.

PURPOSE: Determination of the reasons for clinically significant unplanned ametropia following cataract surgery and the results of management of the ametropia. METHODS: Retrospective review of 11 consecutive cases of tertiary referral for management of pseudophakic ametropia to the authors. Corrective surgery involved either lens implant exchange or LASIK refractive surgery. Final outcome was assessed by uncorrected and best spectacle corrected visual acuity and manifest refractive outcome. RESULTS: Five cases (45%) were due to significant error in axial length determination at pre-surgery biometry. Six cases (55%) were due to surgeon or surgical team error, where the surgeon implanted a lens of power at variance with that specified pre-operatively. Nine patients elected to undergo refractive surgery to correct the ametropia and 2 elected to wear a spectacle lens. Seven underwent lens implant exchange and 2 patients underwent LASIK keratorefractive surgery. Eight of nine patients were within 1 dioptre of intended spherical equivalent after refractive surgery and 1 patients was -1.5 dioptre myopic. CONCLUSIONS: Most cases of serious unintended ametropia after cataract surgery are avoidable. Care should be taken with the biometry and procedural checks to minimise error. When lens implant exchange or LASIK was performed the final refractive results were satisfactory.

Aphakia, Postcataract↗

PubMed2002

Unilateral multicystic dysplastic kidney: a combined pre- and postnatal assessment.

OBJECTIVE: To review the prenatal assessment of associated renal pathology, non-renal pathology and renal biometry, fetal outcome and postnatal urological management in the presence of unilateral fetal multicystic dysplastic kidney. METHODS: A total of 38 singleton pregnancies with fetal unilateral multicystic dysplastic kidney was studied over a 13-year period. Prenatally, fetal biometry, including head and abdominal circumferences and largest longitudinal diameter of the affected and contralateral kidneys, was performed. The amount of amniotic fluid was assessed. Fetal karyotyping was offered in cases of contralateral renal or non-renal pathology. A MAG 3 scan and voiding cystogram was performed approximately 4 weeks after delivery to establish renal function and to exclude urinary reflux. RESULTS: Unilateral fetal multicystic dysplastic kidney was left-sided in 53% and right-sided in 47% of cases. The fetus was male in 63% and female in 37% of cases. Associated renal and non-renal pathology existed in 21% and 5% of cases, respectively. The fetal karyotype in these subsets was always normal. The longitudinal diameter of the multicystic dysplastic kidney was above the 95th centile in 87%. There was polyhydramnios in three cases and oligohydramnios in two cases. The prematurity rate was 16%. Postnatal examination revealed a non-functional multicystic kidney in 87% (33/38) of cases. Following surgical removal of the affected kidney, these infants progressed normally. Of the remaining five infants, four died because of associated anomalies and one infant developed normally without surgery. CONCLUSIONS: Fetal outcome is determined by associated renal and/or non-renal structural pathology and not by the size/location of the unilateral multicystic dysplastic kidney or amniotic fluid volume.

Amniotic Fluid↗

PubMed2002

Fetal ear length measurement: a useful predictor of aneuploidy?

OBJECTIVE: To determine the usefulness of short ear length (EL) measurement in the prenatal detection of fetuses with chromosomal abnormalities. DESIGN: Fetal EL measurements, routine biometry and complete anatomic survey for fetal abnormalities were prospectively performed by antenatal sonography. SUBJECTS: One thousand eight hundred and forty-eight patients with singleton pregnancies undergoing genetic amniocentesis in the second or third trimester. METHODS: Complete data for EL, biometry and anatomic survey for major structural abnormalities and minor sonographic markers of chromosomal abnormality were available in 1311 fetuses. Of these, 48 (3.7%) had an abnormal karyotype and 1263 (96.3%) had a normal karyotype. Using an EL measurement of < or = 10th percentile for corresponding gestational age in normal fetuses as abnormal cut-off values, detection rates for chromosomal abnormalities by short EL were determined. RESULTS: Among the 48 abnormal karyotypes, 34 were considered significant, and 11 of these 34 (32.4%) fetuses had short EL. In 14 cases, the karyotypic abnormality was considered non-significant and fetal EL was normal in all cases. Of the 34 fetuses with significant chromosomal abnormalities, six (17.6%) on antenatal sonography had no detectable abnormal findings, other than short EL. An increased biparietal diameter (BPD)/EL ratio of > or = 4.0 was also noted in fetuses with an abnormal karyotype, but the sensitivity and predictive value of increased BPD/EL ratio alone or increased BPD/EL ratio in combination with short EL was no better than the sensitivity and predictive value of short EL alone. A combination of short EL and abnormal ultrasound, however, gave a much higher positive predictive value (46%) for significant chromosomal abnormalities. CONCLUSIONS: Our findings suggest that in women at high risk for fetal chromosomal abnormality, a short fetal EL measurement on prenatal ultrasound, either alone or in combination with other sonographically detectable structural abnormalities, may be a useful parameter in predicting fetal aneuploidy.

Aneuploidy↗

PubMed1997

Mild pyelectasis ascertained with prenatal ultrasonography is pediatrically significant.

Isolated 'mild renal collecting system dilatation' (mild pyelectasis) is a common prenatal sonographic finding. An association between mild pyelectasis and fetal aneuploidy has been established, but in the absence of a concomitant anomaly, mild pyelectasis is usually regarded as benign and of no clinical consequence, and follow-up is often not obtained after the initial ascertainment. To test this, we investigated the relationship between mild pyelectasis and (1) progression to hydronephrosis; (2) postnatal vesicoureteral reflux (VUR); and (3) postnatal surgery. Between 1 January 1992 and 1 January 1995, we performed 453 prenatal sonographic examinations of 306 patients with mild fetal pyelectasis and no other anomalies. During the course of a routine sonographic examination, we performed a detailed evaluation of the fetal genitourinary tract, Mild pyelectasis was defined as a pelvocalyceal fluid-filled space with the smallest of two transverse perpendicular sonographic measurements of > or = 4 mm and < 10 mm. Hydronephrosis was defined similarly, but with a measurement of > or = 10 mm. Postnatal urological assessment was obtained with routine renal ultrasonography, and voiding cystourethrography (VCUG), measurement of 99mTc-labelled diethylenetriamine pentaacetic acid (DPTA) mercaptacetyltriglycerine (MAG3), and intravenous pyelogram, as necessary. After exclusion criteria were applied, 294 (96%) patients with isolated fetal pyelectasis were considered. A total of 251 (82%) of these were followed with ultrasonography prenatally and during the postnatal period. Two or more prenatal examinations were carried out in 129 patients (51%) and in 35 (27%) of these cases the biometry progressed to frank hydronephrosis (> 10 mm). In only six (5%) of the cases followed prenatally did the measurement diminish to < 4 mm. We found a greater variability in prenatal renal biometry throughout gestation in infants found to have VUR, when compared with those who had no VUR. On postnatal follow-up, 84 patients had VCUG. Sixteen of these patients (6% of all patients [16/251] and 19% [16/84] of those who had the test) were found to have an abnormal finding. Whereas the prenatal appearance of mild pyelectasis improved in only a small number of cases, we found that it progressed to hydronephrosis in 27% of cases. Postnatal evaluation found VUR to be common in apparent uncomplicated mild prenatal pyelectasis. Although postnatal surgery was necessary in only a small number of cases, surgical intervention was necessary in 33% (four of 12) of those with VUR.

Adolescent↗

PubMed2002

Intra-observer and inter-observer repeatability of anterior eye segment analysis system (EAS-1000) in anterior chamber configuration.

BACKGROUND: Anterior chamber configuration can be assessed via optical or ultrasonic techniques. Scheimpflug photography is a non-invasive method measuring the anterior segment. The Anterior Eye Segment analysis system, EAS-1000, utilises the Scheimpflug principle and was found to have good repeatability. Previous repeatability studies, however, have had limitations in their design. The current study investigated the intra-observer and interobserver repeatability of the EAS-1000. METHODS: Twenty-five healthy young subjects were recruited. The anterior chamber angles in different quadrants were measured by two examiners for interobserver analysis. The first examiner repeated the measurement at another session for intra-observer analysis. The 95% limits of agreement and intra-class correlation coefficient (ICC) were calculated. The anterior chamber depth was also measured and compared with ultrasound biometry. RESULTS: The anterior chamber angle assessment demonstrated good intra-observer (ICC ranging from 0.77 to 0.90 for different quadrants) and interobserver (ICC ranging from 0.68 to 0.81 for different quadrants) repeatability. The 95% intra-observer limits of agreement were within +/-5 degrees. The 95% interobserver limits of agreement were within +/-6 degrees. There was no significant difference between male and female subjects or among angles at different quadrants. The anterior chamber depth was found to be repeatable (ICC > 0.90) with 95% limits of agreement +/-0.1 mm. The anterior chamber depth was shallower than that obtained from ultrasound biometry. CONCLUSIONS: The EAS-100 is a non-invasive instrument which is repeatable for measuring the anterior chamber angle and depth. It provides quick results and is good for screening purposes. There is an under-estimation of anterior chamber depth, as previously reported.

Adolescent↗

PubMed2001

[Toric intraocular lens to correct high astigmatism after penetrating keratoplasty in a pseudophakic eye - a case report].

BACKGROUND: After penetrating keratoplasty residual astigmatism can be treated with various options. Correction with spectacles or contact lenses, methods such as radial keratotomy, photorefractive keratectomy (PRK) or Laser-in-situ keratomileusis (LASIK) are limited only to mild and moderate astigmatism. In laser ablation a sufficient corneal thickness must be ensured. On the other hand surgical correction is performed on transplanted tissue which can increase the risk of allograft rejection. In pseudophakic eyes the implantation of an individually designed toric intraocular lens (IOL) according to keratometry and biometry with a cylindrical power up to 12 D provides an alternative method for correcting higher astigmatism. This individually designed IOL can be implanted additionally to the existing IOL. CASE: A 66-year-old patient presented after penetrating keratoplasty and implantation of an IOL 4 years ago with a visual acuity of 20/160 and residual astigmatism of - 10 D x 151(o). After biometry an individually manufactured toric PMMA-IOL of + 12 D cylindrical and - 9.5 D spherical power was implanted via a sclerocorneal tunnel incision additionally to the existing IOL into the ciliary sulcus. Postoperatively a well centered and stable positioned IOL was found. One year after implantation of the toric IOL the position was still unchanged and the graft had remained clear. Spherical equivalent refraction was + 1,5 D - 3,0 D x 141(o), with an uncorrected visual acuity of 20/60. CONCLUSION: Implantation of a toric intraocular lens in pseudophakic eyes allows the correction of high astigmatism after penetrating keratoplasty. The advantage of this method compared to the keratorefractive options lies in its minor manipulation on the allograft.

Aged↗

PubMed2002

[Uteroplacental and fetal arterial Ultrasound Doppler Flow Velocity measurements in unselected pregnancies as a screening test at 32 to 34 gestational weeks].

OBJECTIVE: We hypothesized a difference in mean values for ultrasound biometry and Doppler flow velocity measurements in uteroplacental and fetal arterial vessels between subgroups with a subsequent normal and pathological [pathological fetal heart rate tracing, operative delivery due to fetal distress, thick meconium, IUGR < 10th centile, prematurity < 37 weeks, APGAR 5' < 7, umbilical artery pH < 7.20, neonatal pediatric hospitalisation] birth result in unselected pregnancies screened at 32 to 34 gestational weeks. PATIENT CHARACTERISTICS AND METHODS: After having obtained informed consent we included 198 singleton pregnancies in an open prospective study and performed a single ultrasound assessment at 32 to 34 gestational weeks to collect biometry and Doppler flow velocity data: angle independent resistance indices (RI, PI) for uteroplacental and umbilical arteries, RI, PI and Vmean (mean blood flow velocity) after angel correction for fetal descending aorta and middle cerebral arteries, (ATL, Ultramark 9, HDI ESP, 4 - 7 MHz curved and 3 - 5 MHz phased array). After delivery, perinatal and neonatal data were collected and pregnancies were grouped accordingly (normal and pathological birth result). RESULTS: Of 198 pregnancies included, 58 fulfilled at least one of the established criteria for a pathological birth result and 17 were born growth restricted (< 10th centile) and/or prematurely (< 37 gestational weeks). Within subgroups (normal /pathological birth result) mean values only differed for uteroplacental RI (p=0.07) and aortic Vmean (p=0.04). Differences were highly significant for normally versus growth restricted/prematurely born fetuses: uteroplacental RI (p=0.01), fetal descending aorta PI (p=0.02) and Vmean (p=0.001), and middle cerebral artery PI (p=0.0008). CONCLUSION: Elevated uteroplacental Doppler flow velocity waveform indices and reduced aortic blood flow velocity might be associated with a pathological birth result and an impaired neonatal status after birth in cohorts of unselected pregnancies.

Adolescent↗

PubMed2005

[Imaging of the anterior eye chamber with optical coherence tomography].

BACKGROUND: Optical coherence tomography (OCT) represents a high-resolution diagnostic method which can be used to precisely image the anterior eye segment. Further developments in scanning technology and data evaluation allowed to visualize the entire anterior eye segment in one image, and the purpose of this study was to clinically evaluate this new system. PATIENTS AND METHODS: The studied OCT system was adapted to a slit-lamp and allowed us to image the anterior segment with an axial resolution of 10 microm at a scanning rate of 200 Hz with a depth of 7 mm and a maximal width of 15 mm. In selected cases the clinical value of anterior segment OCT was assessed. The reproducibility and level of agreement of anterior chamber depth measurements were assessed during the preoperative examination in 49 cataract surgery patients and compared to ultrasound (US) biometry (10 MHz). RESULTS: The studied anterior segment OCT allowed the cross-sectional imaging of the entire anterior eye segment. Changes of the anterior chamber before and after cataract surgery or surgical iridectomy were visualised. Furthermore, the findings of the anterior chamber after implantation of an iris-fixated intraocular lens (IOL) and an iris prosthetic system could be assessed. The reproducibility of the anterior chamber depth measurement was +/- 22 microm (OCT) and +/- 76 microm (US). The mean difference between optical and acoustic values was 1 microm (0.03 % p = 0.921) and the limits of agreement (95 % confidence interval) were 260 microm (8.58 %). CONCLUSIONS: The anterior segment OCT proved to be a helpful diagnostic method. The cross-sectional visualisation of the entire anterior chamber allowed us to assess important values for the implantation of iris-fixated IOL and other changes after surgical procedures. The resolution and reproducibility were higher than for conventional ultrasound biometry.

Aged↗

PubMed1982

[Ophthalmologic ultrasound diagnosis--current training programs in Germany, Austria, Switzerland].

In these three countries the application of diagnostic ultrasound in ophthalmology is restricted, with few exceptions, only to institutions having access to in-patients. This situation is based on the organization of medical care and does not depend on the technical evolution of the equipment. Consequently the annual rate of trainees in ophthalmic ultrasound is relatively low, but a comprehensive training programme is needed in this field. The requisite training subjects are described. They include a technical and a clinical programme for both pulse-echo (A, B, M, D mode) and Doppler techniques as applied for biometry as well as for tissue and vascular examination. Some data are given regarding training facilities, aids and courses in the three countries. The concept and organization of a 5-day course (Bonn/Würzburg Course, Directors: W. Buschmann/H.G. Trier) is described in greater detail. For ophthalmic ultrasonography, testing and calibration of system parameters both for equipment and transducers is necessary for obtaining reliable and reproducible results. Examples are given for the organization of technical training in the practical course. The 1981 guidelines of the "Kassenärztliche Bundesvereinigung", Cologne, are discussed. These regulations define minimum requirements for both ultrasonic training and equipment in the FRG. Finally, a few controversial aspects of the teaching (quality assurance, role of biometry) are mentioned.

Austria↗

PubMed1998

Prenatal sonographic findings associated with malignant astrocytoma following normal early third-trimester ultrasonography.

We present an unusual case in which sonographic assessment at 33 weeks' gestation, 5 weeks following a normal fetal anatomical survey and biometry, demonstrated a large, irregular-shaped, echogenic, suprasellar midline intracranial mass occupying the anterior and middle fossas. Associated severe obstructive hydrocephalus with "dangling" choroid plexus bilaterally was noted with a markedly thin cortical mantle and increased cranial biometry. Elective cesarean delivery was performed due to the associated craniomegaly at 37 weeks' gestation. Although breathing spontaneously at delivery, the infant subsequently required mechanical ventilation and developed neonatal seizures. A ventriculoperitoneal shunt was placed on Day 3 of life. Transcranial needle biopsy demonstrated malignant astrocytoma (glioblastoma multiforme). This case suggests the rapid development of an intracranial malignant astrocytoma over a relatively short period of time. The significant ultrasonographic finding of an intracranial, destructive fetal deformation, following a normal examination 5 weeks previously, demonstrates the limitations of screening ultrasonography in predicting perinatal outcome.

Adult↗

PubMed1988

[Comparison of Doppler flow measurements of the arcuate artery and uterine artery in fetal growth retardation].

Transabdominal Doppler velocimetry in the arcuate arteries has been the widest used technique for the assessment of uterine perfusion despite theoretical and physiological drawbacks. The size of arcuate arteries is beyond the resolution of modern scanners. They represent terminal branches of the uterine vasculature and do not provide information regarding total uterine blood supply. Transvaginal Doppler velocimetry of the main uterine arteries on its course through the parametrium by means of a newly developed frontally radiating 240-degree "panorama" sector scanner promised a solution. The aim of the study was to compare the A/B ratios in both arteries (i.e. arcuate vs. main uterine) in pregnancies with a growth retarded fetus below the 10th percentile, as defined by ultrasound biometry. We wondered firstly which vessel better demonstrates velocity waveforms leading to growth retarded newborns defined by a birth weight beyond the 10th percentile (Hohenauer) and secondly, how frequently pathological A/B ratios in the uterine vessels are associated with pathological A/B ratios in the umbilical arteries. In 25 growth retarded fetuses (ultrasound biometry), we found more often pathological waveforms in the arcuate arteries (n = 20) than in the main uterine arteries (n = 18). Pathological waveforms in all three vessels (arcuate, main uterine, umbilical) were found in 12, in the arcuate and umbilical vessels in 13, and in the main uterine and in umbilical artery in 17 cases. Six fetuses were within the normal weight range at delivery indicating normal fetal growth. Pathological A/B ratios in the main uterine artery were more often associated with a growth retarded newborn.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1998

[Eyeball growth after successful glaucoma surgery in the 1st year of life--follow-up values for primary congenital glaucoma].

BACKGROUND: Echographic biometry of the ocular axial length is a helpful criterion in diagnosis and follow-up of primary congenital glaucoma. However, quantitative assessment of ocular growth following successful primary glaucoma surgery in the first year of life is hardly to find in literature. PATIENTS AND METHODS: In 36 eyes from 21 patients (mean age 4.4 +/- 2.4 months) with primary congenital glaucoma Ascan biometry was performed under general anesthesia before and 7.2 +/- 4.2 months following successful primary glaucoma surgery and retrospectively summarized. RESULTS: Preoperative axial length was 21.7 +/- 2.5 mm, postoperative axial length was 22.4 +/- 1.6 mm. Ocular growth was significantly stronger in eyes with a preoperative axial length < 20 mm (p = 0.0012) and in children younger than 3 months at surgery (p = 0.0004). CONCLUSIONS: Preoperative axial length and age are basic factors for the interpretation of ocular growth following glaucoma surgery in primary congenital glaucoma. Temporary cessation of ocular growth is a frequent finding after successful pressure-reducing surgery in eyes with axial length > 22 mm and in children aged 3 months or older.

Eye↗

PubMed2003

Doppler assessment of the fetal cerebral hemodynamic response to moderate or severe maternal anemia.

OBJECTIVE: The purpose of this study was to evaluate the fetal vascular adaptation to moderate and severe maternal anemia. STUDY DESIGN: Biometry; amniotic fluid index; uterine, cerebral, and umbilical Doppler; and maternal hemoglobin level were measured at admission and 8 days after treatment. RESULTS: Group 1 consisted of 16 pregnancies (maternal hemoglobin level, 6.9 +/- 0.6 g/100 mL); group 2 consisted of 23 pregnancies (maternal hemoglobin level, 5 +/- 0.6 g/100 mL). At admission the cerebral and cerebral/umbilical Doppler indexes, amniotic index, and biometry were lower in group 2. The uterine index was normal in both groups. An abnormal fetal heart rate was found in group 2 only (48%). At day 8, maternal hemoglobin level and amniotic index increased more in group 2 than in group 1. The cerebral index and the cerebral-to-umbilical resistance ratio increased only in group 2. The abnormal fetal heart rate disappeared in group 2. CONCLUSION: Only severe maternal anemia (maternal hemoglobin level, <6 mg/L) triggered fetal cerebral vasodilation and reduced amniotic volume.

Adult↗

PubMed2005

Predicting late-onset growth abnormalities using growth velocity between trimesters.

OBJECTIVES: To determine whether growth velocity parameters derived from routine prenatal ultrasound measurements at first, second and third trimester can identify normal growth at term as well as late-onset growth abnormalities. MATERIAL AND METHODS: Longitudinal study of fetal growth in normal singleton pregnancies with three normal ultrasound examinations and delivered at term. Fetuses were classified into 3 groups (<10th percentile, 10-90th percentile, >90th percentile) based on birth weight. Multiple regression on birth weight classification was used to build up a prediction equation of fetal growth potential (FGP) based on fetal biometry and fetal growth velocity parameters between ultrasound examinations. Best cut-off value for FGP predicting growth restriction and macrosomia were defined. RESULTS: 356 pregnancies were included. Fetal biometry growth velocities between examinations were calculated for all measurements. Using best cut-off values, the estimated sensitivity, specificity and odds ratio were: 60% [44;74], 91% [89;92] and 14.55 [6.30;33.98] and 53% [36;69], 89% [88;91] and 10 [4.27;23.49] for the prediction of growth restriction and macrosomia, respectively. DISCUSSION: Fetal growth potential can be derived and calculated from standard ultrasound measurements. It can improve identification of these fetuses at risk for late-onset growth abnormalities and their related morbidity.

Adolescent↗

PubMed2004

Antenatal fetal surveillance.

PURPOSE OF REVIEW: Antenatal fetal surveillance is a field of increasing importance in modern obstetrics, especially as results in perinatal care have recently made dramatic progress. It is an evolving field, and it is no longer acceptable just to wait and see when problems arise in pregnancy. During the past few decades many studies have shown that antenatal surveillance in unselected populations is of little value. However, high-risk patients benefit from antenatal fetal surveillance, especially women with pregnancy problems associated with intrauterine growth restriction. RECENT FINDINGS: This review shows that modern antenatal fetal surveillance is based on fetal heart rate monitoring, ultrasound biometry and amniotic fluid assessment, Doppler blood flow studies of fetal and uteroplacental circulation, and an evaluation of biophysical fetal parameters. SUMMARY: Used in combination these methods lead to improvements in fetal morbidity and mortality. The aim of future research should be to minimize the risks of fetal morbidity and mortality further by the optimal timing of delivery. Better organization of healthcare systems may improve our ability to identify at-risk patients during pregnancy. There is potential to improve the specificity of fetal surveillance tests, e.g. better methods of biometry and amniotic volume estimation with three-dimensional ultrasound and measurements of subcutaneous tissue. Improved knowledge of fetal physiology can be gained from research on fetal circulation with Doppler studies. Computer analysis of the fetal heart rate can increase the specificity of that test, and artificial neural networks may enhance the ability to evaluate the optimal use of integrated testing.

Amniotic Fluid↗

PubMed2004

Teenage antenatal clinics may reduce the rate of preterm birth: a prospective study.

OBJECTIVE: To examine whether teenage antenatal clinics reduce the incidence of preterm birth. DESIGN: A multicentre prospective study was performed. SETTING: Three Australian hospitals with maternity services. POPULATION: Consecutive teenage patients (N= 731) were approached at their first or second antenatal visit. METHODS: Cases were women attending multidisciplinary teenage antenatal clinics and controls attended general hospital-based antenatal clinics. Teenage antenatal clinics involved multidisciplinary care and included guidelines to screen and treat all patients for infectious and social pathology. General antenatal clinic care was in accordance with Australian standards. MAIN OUTCOME MEASURES: Preterm birth, newborn biometry adjusted for gestational age, breastfeeding and contraception plans at discharge. RESULTS: Consent was obtained from 651 (89%) patients. Teenage pregnancy clinic patients were significantly less likely to present with threatened preterm labour (OR 0.45; 95% CI 0.29-0.68), preterm, prelabour, prolonged rupture of membranes (OR 0.34; 95% CI 0.18-0.63) or deliver preterm (OR 0.40; 95% CI 0.25-0.62) compared with those from general clinics. However, there was no independent effect of clinic care upon newborn biometry outcomes. Clinic care did not significantly alter rates of initiation of breastfeeding in hospital. However, significantly more of the teenage antenatal clinic mothers were discharged on contraception (OR 1.58; 95% CI 1.07-2.25). CONCLUSION: Teenage-specific antenatal clinics may reduce the rate of preterm birth.

Adolescent↗

PubMed1993

Estimation of the thickness of the crystalline lens from on-axis and off-axis Scheimpflug photographs.

Measurement of human lens biometry directly from Scheimpflug images of the anterior ocular segment may be impossible when pupil size precludes an adequate Scheimpflug view of the posterior lens surface. The authors describe a simple and accurate geometric method of overcoming this problem by estimating the true lens thickness from pairs of on-axis and off-axis Scheimpflug images. The method is validated and the variability of the estimate is quantified. This new method has utility in the study of lens biometry in subjects with large lenses whose pupils cannot be adequately dilated.

Anthropometry↗

PubMed2006

Prevalence and associations of anisometropia and aniso-astigmatism in a population based sample of 6 year old children.

AIM: To study the distribution of anisometropia and aniso-astigmatism in young Australian children, together with clinical and ocular biometry relations. METHOD: The Sydney Myopia Study examined 1765 predominantly 6 year old children from 34 randomly selected Sydney schools during 2003-4. Keratometry, cycloplegic autorefraction, and questionnaire data were collected. RESULTS: Spherical equivalent (SE) anisometropia (> or =1 dioptre) prevalence was 1.6% (95% confidence interval (CI) 1.1% to 2.4%). Aniso-astigmatism (>or =1D) prevalence was 1.0% (CI: 0.6% to 1.6%). Both conditions were significantly more prevalent among moderately hyperopic (SE > or =2.0D) than mildly hyperopic (SE 0.5-1.9D) children. Myopic children (SE < or =-0.5D) had higher anisometropia prevalence. Neither condition varied by age, sex, or ethnicity. In multivariate analyses, anisometropia was significantly associated with amblyopia, odds ratio (OR) 29, (CI: 8.7 to 99), exotropia (OR 7.7, CI: 1.2 to 50), and neonatal intensive care unit (NICU) admission (OR 3.6, CI: 1.1 to 12.6). Aniso-astigmatism was significantly associated with amblyopia (OR 8.2, CI: 1.4 to 47), maternal age >35 years (OR 4.0, CI: 1.3 to 11.9), and NICU admission (OR 4.6, CI: 1.2 to 17.2). Anisometropia resulted from relatively large interocular differences in axial length (p<0.0001) and anterior chamber depth (p = 0.0009). Aniso-astigmatism resulted from differences in corneal astigmatism (p<0.0001). CONCLUSION: In this predominantly 6 year old population, anisometropia and aniso-astigmatism were uncommon, had important birth and biometry associations, and were strongly related to amblyopia and strabismus.

Amblyopia↗