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PubMed2003

Multivariable analysis of tests for the diagnosis of intrauterine growth restriction.

OBJECTIVES: To describe how data from antenatal fetal ultrasound biometry, amniotic fluid index and umbilical artery Doppler can be appropriately combined using multivariable models and to investigate how the addition of these ultrasound parameters influences the ability to predict intrauterine growth restriction (IUGR). METHODS: This was a prospective cohort study involving 274 low-risk pregnancies undergoing serial ultrasound examination at predetermined intervals. Standard deviation (Z) scores of the last values for fetal abdominal area (FAA), growth velocity of the FAA, amniotic fluid index (AFI) and umbilical artery Doppler pulsatility index prior to delivery were calculated for 260 fetuses. Customized estimated fetal weight (cEFW) centiles were also calculated using the last EFW before delivery after adjustment for fetal gender, gestational age, birth order and maternal weight, height and ethnic origin. Following delivery the neonatal ponderal index was calculated and centile position obtained. A neonatal ponderal index <25(th) centile served as the main outcome measure for diagnosis of IUGR. Logistic regression analysis was used to delineate the predictive value of the three fetal growth tests FAA, FAA growth velocity and cEFW and the additional values of AFI and pulsatility index of the umbilical artery. RESULTS: The areas under the receiver-operating characteristics (ROC) curves (95% confidence interval) for FAA, FAA growth velocity and cEFW alone were 0.819 (0.748-0.891), 0.784 (0.699-0.869) and 0.74 (0.643-0.837), respectively, in the prediction of a neonatal ponderal index <25(th) centile. The addition of both the AFI and pulsatility index to FAA, FAA growth velocity and cEFW generated small increases in the areas, to 0.831 (0.758-0.904), 0.817 (0.735-0.899) and 0.766 (0.672-0.859), respectively. These improvements in diagnostic prediction were not statistically significant. CONCLUSIONS: The addition of AFI and umbilical artery pulsatility index to the fetal biometry parameters did not significantly increase the ROC areas in the study population. The approach applied in this study is useful in the context of hypothesis generation. Further studies using larger data sets and other predictors should be carried out using the analytical techniques outlined in this paper to determine the contribution of various antenatal tests in the prediction of IUGR.

Amniotic Fluid↗

PubMed2004

Practical approach to prenatal posterior fossa abnormalities using MRI.

This review focuses on the optimum use of fetal MRI as an additional imaging tool to sonographic data in posterior fossa (PF) abnormalities in the second and third trimesters of gestation. We have chosen three particular situations to demonstrate the value of MRI as a complementary investigation to US: (1) the pattern of increased fluid-filled space of the PF, (2) decreased cerebellar sonographic biometry and (3) the diagnosis of focal echogenic lesions of the cerebellum. For increased fluid-filled space of the PF and decreased cerebellar sonographic biometry, a practical approach is proposed, largely based on prenatal imaging, especially MRI.

Cranial Fossa, Posterior↗

PubMed2005

[Transient visual decrease after photodynamic therapy].

BACKGROUND: After photodynamic therapy (PDT) some patients complain about a transient decrease of visual acuity during the first postoperative week. PATIENTS AND METHODS: Prior to and at 2 days and 1 week after PDT the following parameters were measured: (1) best corrected visual acuity (VA), (2) changes in refraction, and (3) A scan ultrasound biometry was carried out. Linear and 3-D optical coherence tomography was performed in three cases. A total of 53 PDT treatments were followed-up in 24 patients. RESULTS: Comparison of the pre- and postoperative refraction demonstrated a mean hyperopic shift of +0.35 diopters (dpt) in 43% of treatments (23/53) on the second postoperative day. The hyperopic shift reduced to +0.07 dpt after 1 week. The best corrected VA remained stable or was even better in 68% (36/53) on the second postoperative day. A decrease in VA could be noticed in 32% (17/53) at this time which declined to 23% (12/53) after 1 week. Measurement of the cornea-retina distance using A-scan ultrasound biometry disclosed a mean axial reduction of 0,13 mm at the second postoperative day. This correlates closely with an average hyperopic shift of 0,35 dpt. OCT examination disclosed a transient macular edema in the treated retinal areas. CONCLUSIONS: A transient hyperopic shift can be measured in 43% on the second postoperative day. The subjective decrease in visual acuity measured over the postoperative days was mainly due to a transient hyperopic shift in our patients. OCT findings disclosed a transient macular edema of the retina treated with PDT, which may relate to a hyperopic shift.

Aged↗

PubMed1996

Fetal cerebral Doppler studies as a predictor of perinatal outcome and subsequent neurologic handicap.

OBJECTIVE: To study the use of middle cerebral arterial Doppler findings in a group of high-risk fetuses as a predictor of adverse perinatal outcome, including subsequent neurologic handicap. METHODS: A group of very high-risk fetuses was recruited over a 2-year period for study. Weekly fetal biometries and Doppler studies of the umbilical artery and middle cerebral arteries were carried out until delivery. Main outcome indices analyzed included birth weight ratio (ratio of observed birth weight to mean birth weight for gestation), days of ventilator requirement, neonatal intracranial hemorrhage or periventricular leukomalacia, necrotizing enterocolitis, and follow-up data on major neurologic handicap and death. RESULTS: Seventy-four patients were recruited. One hundred thirty-four sets of examinations were made and prospective follow-up data were available for up to 2 years. The ratio of the umbilical and middle cerebral arterial resistance index was found to be inversely proportional to the birth weight ratio. Fetuses who had a high prenatal umbilical-cerebral Doppler ratio had significantly lower birth weight ratios than those with normal findings (0.72 versus 0.92; P < .001). The ratio was a more sensitive marker for growth restriction (sensitivity 78%) than conventional fetal biometry and umbilical arterial systolic-diastolic ratio. However, fetuses with high ratios did not have higher incidences of perinatal complications or subsequent neurologic handicap. CONCLUSION: Prenatal cerebral vasodilation is a sensitive marker for growth restriction and it seems to be a physiologic response to hypoxia. Fetuses with intrauterine cerebral vasodilation do not have increased risk for subsequent gross neurologic damage.

Adult↗

PubMed2004

First trimester ultrasound screening is effective in reducing postterm labor induction rates: a randomized controlled trial.

OBJECTIVE: This study was designed to test the null hypothesis that first trimester ultrasound crown-rump length measurement for gestational age determination will result in no difference in the rate of induction of labor for postterm pregnancy, compared with second trimester biometry alone. STUDY DESIGN: Two hundred eighteen women were randomly assigned to receive either first trimester ultrasound screening or second trimester ultrasound screening to establish the expected date of confinement. Sample size was calculated by using a 2-tailed alpha=.05 and power (1-beta)=80%. Data were analyzed with chi(2) and Fisher exact tests. RESULTS: Of 104 women randomly assigned to the first trimester screening group, 41.3% had their gestational age adjusted on the basis of the crown-rump length measurement. Of 92 women randomly assigned to the second trimester screening group, 10.9% were corrected as a result of biometry (P <.001, relative risk=0.26, 95% CI=0.15-0.46). Five women in the first trimester screening group and 12 women in the second trimester screening group had labor induced for postterm pregnancy (P=0.04, relative risk=0.37, 95% CI=0.14-0.96). CONCLUSION: The application of a program of first trimester ultrasound screening to a low-risk obstetric population results in a significant reduction in the rate of labor induction for postterm pregnancy.

Adolescent↗

PubMed2005

The relationship between refractive and biometric changes during Edinger-Westphal stimulated accommodation in rhesus monkeys.

Experiments were undertaken to understand the relationship between dynamic accommodative refractive and biometric (lens thickness (LT), anterior chamber depth (ACD) and anterior segment length (ASL=ACD+LT)) changes during Edinger-Westphal stimulated accommodation in rhesus monkeys. Experiments were conducted on three rhesus monkeys (aged 11.5, 4.75 and 4.75 years) which had undergone prior, bilateral, complete iridectomies and implantation of a stimulating electrode in the Edinger-Westphal (EW) nucleus. Accommodative refractive responses were first measured dynamically with video-based infrared photorefraction and then ocular biometric responses were measured dynamically with continuous ultrasound biometry (CUB) during EW stimulation. The same stimulus amplitudes were used for the refractive and biometric measurements to allow them to be compared. Main sequence relationships (ratio of peak velocity to amplitude) were calculated. Dynamic accommodative refractive changes are linearly correlated with the biometric changes and accommodative biometric changes in ACD, ASL and LT show systematic linear correlations with increasing accommodative amplitudes. The relationships are relatively similar for the eyes of the different monkeys. Dynamic analysis showed that main sequence relationships for both biometry and refraction are linear. Although accommodative refractive changes in the eye occur primarily due to changes in lens surface curvature, the refractive changes are well correlated with A-scan measured accommodative biometric changes. Accommodative changes in ACD, LT and ASL are all well correlated over the full extent of the accommodative response.

Accommodation, Ocular↗

PubMed2004

Gunshot injuries to the head and brain caused by low-velocity handguns and rifles. A review.

OBJECTIVES: Reconstruction of brain injuries is a basic task of forensic neuropathology. For better understanding of the wound ballistics of gunshot injuries to the brain caused by low-velocity firearms (E(o) < 550 J), we reviewed the respective contributions of: (1) biomechanical reconstruction by postmortem imaging techniques, (2) biometry of the extent of very early microscopic tissue destruction, and (3) microscopic studies on the type and extent of early microscopic reactions around the permanent missile track. MATERIAL AND METHODS: A selected case material of 47 victims of lethal gunshot wounding to the brain was studied. (1) Computed tomography (CT) and magnetic resonance imaging (MRI) techniques were compared with macroscopic findings in 17 cases. (2) Morphometric evaluation of the zones of cellular and axonal destruction around the permanent track was performed in 20 cases (survival time: <90 min). (3) Microscopic studies of the emigration of leukocytes and macrophages plus axonal expression of beta-amyloid precursor protein (beta-APP) were conducted in 10 cases (survival time: >90 min). RESULTS AND CONCLUSIONS: (1) Imaging procedures provided valuable information on entrance and exit wounds, the missile track and secondary changes. (2) Biometry revealed a destruction zone of ca. 3.6 cm around the permanent track corresponding to the "temporary cavity". (3) Microscopic studies of reactive changes demonstrated axonal injury at sites remote from the permanent cavity that could explain the very early respiratory arrest following low-velocity gunshot injury.

Amyloid beta-Protein Precursor↗

PubMed2006

Refractive lens exchange in keratoconus.

PURPOSE: To evaluate the visual results and complications of refractive lens exchange to correct myopia associated with early-stage keratoconus. SETTING: Private practice, Siena, Italy. METHODS: This prospective noncomparative interventional series comprised 34 consecutive eyes of 20 patients with stages I to II keratoconus. Mean patient age was 56.7 years +/- 10.4 (SD). Preoperative mean spherical equivalent (SE) was -11.0 +/- 4.65 diopters (D), (range -5.75 to -22). Ultrasound biometry was performed using videokeratographic central K-readings and the Holladay 2 formula. An intraoperative handheld autorefractor was used to check the power of implanted intraocular lenses. RESULTS: Intraocular lens exchange due to inaccurate power occurred in 11 eyes (32%; 9 eyes intraoperative, 2 eyes postoperative). At 12 months, mean SE was -1.31 +/-1.08 D and mean defocus equivalent was 1.94 +/- 1.57 D. Twenty-two eyes (65%) were within +/-2 D of defocus equivalent, 16 eyes (47%) were within +/-1 D, and 3 eyes (9%) were within +/-0.5. Mean surgically induced astigmatism (vector analysis) was 0.54 +/- 0.43 D. Preoperative mean best spectacle-corrected visual acuity (BSCVA) was 0.55 +/- 0.20, and postoperative mean BSCVA was 0.76 +/- 0.23; the difference was statistically significant (P<.05; 95% confidence interval, 0.19 to 0.25). Postoperative mean uncorrected visual acuity was 0.48 +/- 0.25. The safety index was 1.38, and the efficacy index was 0.87. Complications were posterior vitreous detachment (9%) and dysphotopsia phenomena (15%). Corneal endothelial cell density at 12 months decreased by 6.3%. CONCLUSION: Refractive lens exchange in keratoconic eyes predictably corrected myopia. However, ultrasound biometry was inaccurate in almost one third of eyes. Intraoperative autorefractometry is recommended to improve refractive outcome.

Aged↗

PubMed1998

An alternative for women initially declining genetic amniocentesis: individual Down syndrome odds on the basis of maternal age and multiple ultrasonographic markers.

OBJECTIVE: Our purpose was to develop a method of calculating the individual odds of Down syndrome on the basis of a combination of maternal age and multiple ultrasonographic parameters that can be used to counsel women at high risk who initially decline amniocentesis. STUDY DESIGN: Maternal age and ultrasonographic biometry data were collected prospectively on 3254 normal and 30 Down syndrome singleton fetuses between 15 and 24 weeks' gestation. Humerus length data were expressed as multiples of the normal median. Log transformation of the humerus length data permitted their expression in gaussian frequency distributions and the calculation of likelihood ratios for Down syndrome on the basis of humerus length. We also developed likelihood ratios on the basis of the degree of nuchal skinfold thickening and the presence or absence of hyperechoic fetal bowel and hypoplastic fifth digit. RESULTS: The ultrasonographic parameters and maternal age did not significantly correlate with each other and were significant independent predictors of Down syndrome. We therefore calculated the individual odds of Down syndrome by using the product of the age-related risk and the likelihood ratios associated with nuchal thickening, humerus length shortening, and the presence or absence of hyperechoic fetal bowel or fifth digit hypoplasia, respectively. At a Down syndrome risk level of >1:50, a 60.0% detection rate with 4.5% false-positive rate was observed with a screen-positive rate of 5.5%, positive predictive value of 1:10, and odds ratio (95% confidence interval) of 28.4 (12.8 to 64.0). CONCLUSION: This is the first report of individual odds calculation based on multiple midtrimester biometry parameters and maternal age. The screening efficiency is similar to that reported with triple-analyte serum screening. These data are useful for counseling women who are at increased Down syndrome risk and initially decline amniocentesis.

Adult↗

PubMed1999

Sonographic identification of fetuses with Down syndrome in the third trimester: a matched control study.

OBJECTIVE: To determine sonographic findings in Down syndrome fetuses in the third trimester. METHODS: Down syndrome fetuses who had third-trimester ultrasound examinations between 25 and 41 weeks' gestation were matched for gestational age with three controls each. Fetal structural anomalies, Down syndrome dysmorphology markers (abnormal facial profile, sandal gap, tongue thrusting, clinodactyly, or hypoplastic middle phalanx of the fifth finger), and abnormal long-bone biometry (femur, humerus, tibia, and fibula; femur length to biparietal diameter ratio; and femur length to abdominal circumference ratio were abstracted from the ultrasound reports. The fetal face, hands, feet, profile, and cardiac outflow tracts are routinely evaluated in our center. RESULTS: Seventeen fetuses with Down syndrome who had third-trimester ultrasound evaluations were identified. Anomalies included cardiac defects (five), tongue thrusting (three), clinodactyly (three), abnormal profile (three), sandal gap (two), and duodenal atresia (two). Of the 17 fetuses, at least one long-bone abnormality was found in 13, at least one structural or biometric anomaly was found in 15, and at least two abnormal findings existed in 11. Abnormal ultrasound findings, including structural anomalies, short bones, and Down syndrome dysmorphology markers, were more common in cases than in matched controls. CONCLUSION: At least one abnormal ultrasound finding was present in 15 of 17 fetuses, and abnormal bone measurements or ratios were discovered in 13 of 17. Abnormal long-bone biometry at third-trimester ultrasound should raise the suspicion of fetal Down syndrome.

Adult↗

PubMed1999

Experimental animal myopia models are applicable to human juvenile-onset myopia.

Landmark explorations by Hubel and Wiesel investigating the importance of visual impressions in postnatal development of the visual system demonstrated that neural connections and eye growth can be affected by the absence of a clear retinal image during a critical period of postnatal development. Fundamental theories on neural plasticity and deprivation have recently been established that presume that a reduced quality of the retinal image during infancy and early childhood triggers an elongation of the posterior chamber of the eye, a so-called form deprivation myopia (FDM). In a retrospective multicenter study of 187 patients who suffered from phlyctenular keratitis with corneal opacification since early childhood, we reviewed data on gender, year and age at onset of the disease, refraction, and ultrasound biometry. Compared with the average refraction of +0.5 diopter (D) found in the general population, the mean refraction of -4.43 D that we found in our study demonstrated a marked shift toward myopia of almost 5 D. Patients with an early onset of phlyctenular keratitis had considerably higher myopia (-6.68 D) than those with a late onset (-1.67 D). Additionally, an axial elongation was confirmed by ultrasound biometry. Our average, axial length was 26.53 mm, compared with the epidemiologic mean of 24.00 mm. This myopic shift of 2.53 mm was caused mainly by an enlarged vitreous cavity. These results support the finding that blur can affect eye growth and lead to FDM not only in animal experiments but also in human beings.

Age of Onset↗

PubMed1996

Endoscopic intrauterine fetal therapy: a monkey model.

OBJECTIVES: Prenatal ultrasonographic investigations have led to an increasing number of prenatally detected abnormalities, of which a large number involves the urogenital tract. This study was performed to evaluate if endoscopic intra-amniotic access is possible in primates. METHODS: In 10 midtrimester rhesus monkeys (Macaca mulatta), endoscopic intrauterine fetoscopy was performed with three access cannulas. Using a Seldinger technique, a vascular access system, and a pediatric laparoscopy set, intra-amniotic inspection was attempted. Fetal growth throughout pregnancy was monitored by ultrasonographic measurements of fetal biometry. RESULTS: Intrauterine access could successfully be achieved in 10 rhesus monkeys with three cannulas. After partial amniotic fluid exchange, adequate fetoscopy was always possible. Two monkeys aborted on the second and sixth postoperative days. Serial ultrasonographic investigations for fetal biometry showed no disturbance of the intrauterine growth patterns in the remaining 8 monkeys. CONCLUSIONS: We currently conclude that the rhesus monkey model for experimental intrauterine endoscopic surgery may be suitable for study of the developmental abnormalities of the genitourinary tract.

Animals↗

PubMed2006

[Assessment of the Quantel Medical 20-Mhz Ultrasound Cinescan in intraocular measurements].

BACKGROUND AND OBJECTIVE: Evaluation of the Quantel Medical 20-MHz Ultrasound Cinescan using a closed transducer in intraocular measurements and its reproducibility. PATIENTS AND METHODS: We measured sulcus-to-sulcus distance of 40 control eyes using the20-MHz Cinescan. Then we compared the sonography to the Oculus Pentacam based on the Scheimpflug principle in the measurements of anterior chamber depth, cornea-to-implant distance, and implant-to-crystallin lens distance in patients who underwent phakic implantation (56 eyes). RESULTS: With this technique, the sulcus-to-sulcus distance can be measured with a reproducibility of 86%-88% (p<0.05). The authors show that the corneal diameter is not correlated with the sulcus measurement (R=24%, p<0.05). DISCUSSION: Several techniques are used to quantify anterior segment biometry. Some of these methods, such as White-to-White, are too empirical and others, such as the Scheimpflug camera - for example the EAS-1000 (Nidek) - or high-frequency ultrasound - Ultrasound BioMicroscopy UBM P45 (Paradigm) - are too expensive. The 20-MHz Cinescan has good reproducibility and provides easier access to anterior segment biometry. CONCLUSION: The 20-MHz Cinescan appears to be an accessible technique that may become a useful tool in the refractive surgery of the phakic intraocular lens.

Adult↗

PubMed2002

Surgical identification of posterior lenticonus.

A 79-year-old patient was referred for cataract and high myopia. His optometrist noted difficult refraction. Biometry predicted an emmetropic intraocular lens power of +22.0 diopters. During cataract extraction, the typical features of posterior lenticonus were noted. A careful look for posterior lenticonus is suggested in cases in which there is a discrepancy between the biometry and refraction and no significant nuclear sclerosis to account for the high myopia. Surgeons should be aware of dehiscence or thinning of the posterior capsule while doing cataract extraction in these patients.

Aged↗

PubMed2002

Refractive error and visual outcome after cataract extraction.

PURPOSE: To determine the range of biometry prediction error of the postoperative refraction and the visual outcome after cataract surgery. SETTING: Postgraduate teaching hospital. METHODS: Refraction and visual outcomes were recorded prospectively for a consecutive case series of 1817 cataract procedures. Complete preoperative and postoperative data were available for 1676 eyes (92.4%). The paired mean error of the difference between the predicted and achieved refraction, the percentages falling within +/-0.50 diopter (D), +/-1.00 D, and +/-2.00 D, and the values that contained 99% of data points were then calculated. The number that achieved a final Snellen visual acuity of 6/12 was determined in all eyes and in eyes without preoperative ocular comorbidity. This analysis was repeated in 1265 eyes that received a single intraocular lens (IOL) design (C10UB/C11UB) after phacoemulsification through a clear corneal incision. RESULTS: The paired mean error of the difference between the predicted and achieved postoperative refraction in all eyes was -0.32 D +/- 1.05 (SD); 72.3% of eyes were within +/-1.00 D of the planned refraction, with bounds of 99% of observation of +2.92 D and -3.98 D. In the single IOL group, the paired mean error was -0.32 +/- 0.94 D; 74.2% of eyes fell within +/-1.00 D of the planned refraction, with bounds of 99% of observation of +2.54 D and -3.81 D. Axial length did not determine the magnitude of the biometry prediction error. At discharge from the service, 86.9% of all eyes and 95.4% of eyes without preoperative ocular comorbidity achieved a final corrected Snellen acuity of 6/12. CONCLUSION: These data provide benchmark information that can be used to monitor clinical practice.

Aged↗

PubMed1993

Exchange of IOGEL hydrogel one-piece foldable intraocular lens for bag-fixated J-loop poly(methyl methacrylate) intraocular lens.

In 1990, IOGEL lenses placed in the capsular bag were reported to displace into the vitreous after neodymium:YAG (Nd:YAG) laser capsulotomy. We exchanged a bag-placed IOGEL lens in one patient after erroneous biometry and capsular opacification. The technique and results of lens explantation, aspiration of Elschnig pearls, and in-the-bag implantation of a modified J-loop poly(methyl methacrylate) (PMMA) lens are demonstrated. Removal of the soft and nonadhesive IOGEL lens was easy. The capsule pockets held patent by the flanges of the taco-style IOGEL lens allowed for easy insertion and bag fixation of the J-style loops. Visual acuity improved from 20/60 to 20/20. Centration of the exchange IOL was satisfactory. In a series of 61 Nd:YAG laser posterior capsulotomies, we did not observe the reported tendency of IOGEL lenses to luxate posteriorly. Therefore, we recommend Nd:YAG discission of the posterior capsule as the preferred approach to posterior capsule opacification with IOGEL lenses. However, the technical ease of the technique makes the explantation and replacement of IOGEL lenses by a bag-fixated PMMA IOL a valid option to correct an erroneous biometry.

Cataract Extraction↗

PubMed1999

Axial length measurement and asteroid hyalosis.

PURPOSE: To evaluate the effect of asteroid hyalosis on automated and manual A-scan axial length measurements. SETTING: Celal Bayar University School of Medicine, Manisa, Turkey. METHODS: A case-control study comprised 15 patients with unilateral asteroid hyalosis. The uninvolved eyes were used as controls. Axial length measurements by manual and automated A-scan biometry were performed in both eyes. The main outcome measures were comparisons between manual and automated measurements in asteroid hyalosis eyes with those in control eyes and the assessment of density of asteroid bodies on B-scan photographs. RESULTS: Statistical analysis revealed no significant difference between axial lengths of asteroid hyalosis eyes and those in control eyes with automated (P = .524) or manual (P = .163) methods. Using automated biometry, 1 patient (7%) had a false (6.23 mm) short axial length measurement in the eye with asteroid hyalosis. There were no significant correlations between manual versus automated measurement differences and the density of the asteroid bodies. CONCLUSIONS: The axial length of the eye without asteroid hyalosis can be used to calculate intraocular lens power if the patient has no history of clinical anisometropia.

Adult↗

PubMed1998

Measurement of axial length in the calculation of intraocular lens power.

PURPOSE: Accurate measurement of ocular axial length is essential for accurate intraocular lens (IOL) power calculation. Although it is common practice to average several axial length measurements to improve accuracy, it has been suggested that a single high-quality A-scan ultrasonographic measurement is adequately accurate owing to the high test-retest reliability of A-scan biometry. The aim of this study was to compare the accuracy of a single high-quality A-scan measurement with that of the average of three acceptable measurements in the calculation of IOL power. METHOD: We studied 103 eyes of 103 patients who underwent cataract-IOL surgery. All these patients underwent pre-operative ocular biometry, a standardised extracapsular cataract extraction with posterior chamber IOL implantation, and clinical refraction between 10 and 14 weeks post-operatively. RESULTS: There was no statistically significant difference between the two study groups in measured axial length (p > 0.01), calculated emmetropic IOL power (p > 0.05) or the prediction of post-operative refraction (p > 0.99). CONCLUSION: The use of a single high-quality axial length measurement was as accurate as the mean of three acceptable axial length measurements in the calculation of IOL power.

Cataract Extraction↗