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PubMed2004

[The relationship between keratoconus and axial myopia].

PURPOSE: To study the relationship between keratoconus and axial myopia. METHODS: We prospectively studied refraction and ocular biometry in 100 consecutive keratoconus eyes, and 100 emmetropic eyes. Biometric data (including posterior segment length) were obtained by A-scan ultrasound, Orbscan, and ultrasonic pachymetry. Biometric measurements were compared in both groups. RESULTS: Anterior chamber depth, posterior segment length and axial length were significantly different between the two groups (p<0.001). Axial length was significantly greater in the keratoconus group than in the emmetropic group (23.97 mm versus 23.21 mm, p<0.001). Posterior segment length was significantly greater in the keratoconus group than in the emmetropic group (16.54 mm versus 15.99 mm, p<0.001). In the keratoconus group, the posterior segment length and the subjective spherical equivalent were significantly correlated (rs=-0.45, p<0.001). CONCLUSION: The increase in posterior segment length in the keratoconus group and the correlation between posterior segment length and spherical equivalent in the keratoconus group suggest a statistical relationship between keratoconus and axial myopia.

Adolescent↗

PubMed2005

[Analysis of the eye's anterior segment with optical coherence tomography. Static and dynamic study].

PURPOSE: To study the biometric modifications of the anterior segment depending on accommodation and age. To try and define their possible applications in certain fields of anterior segment surgery, in particular in refractive implants. MATERIAL AND METHOD: Anterior chamber biometry can be very easily studied with 1310-nm wavelength optical coherence tomography. The equipment has a fixation target that can be focused and defocused with negative lenses in order to stimulate natural accommodation. The human anterior chamber was therefore studied during accommodation. We studied 104 eyes of 56 patients aged between 7 and 82 years. Refraction was between +5D and - 5D. A single operator carried out all the measurements. The anterior chamber's horizontal diameter, the anterior chamber's depth, the horizontal pupil diameter and the horizontal radius of curvature of the crystalline lens' anterior pole were measured unaccommodated or after stimulating accommodation. RESULTS: The different static or dynamic measurements were compared to ametropia, age and accommodation. At rest, the average AC diameter was 12.33 mm, the average AC depth was 3.11 mm and the average pupil diameter was 4.26 mm. On average, for 1 D of accommodation, the crystalline lens anterior pole moved forward by 30 microm. There was a 0.3-mm reduction in its radius of curvature and a 0.15-mm reduction in pupil diameter. Several other measurements are illustrated on graphs. CONCLUSIONS: The AC OCT is a user-friendly instrument to evaluate the anterior segment and explore the anterior chamber (cornea, iris, crystalline lens, irido-corneal angle). The 1310-nm light wavelength is blocked by pigments preventing exploration behind the iris. However, the AC OCT is capable of providing good-quality images and a better visualization of the anatomical relationships of the anterior segment, even behind an opaque cornea.

Adaptation, Physiological↗

PubMed1997

Prognostic factors in cervical cancer.

The inadequacy of clinical methods has spurred efforts to develop objective, measurable and reproducible parameters for the spread and growth behaviour of cervical cancer. Morphological methods were applied first. They can be used only on the surgical specimen, but are accessible to biometry. The presented results are based on 479 surgical specimens obtained at radical abdominal hysterectomy for cervical cancers of different sizes. The specimens were processed as frontal giant sections with the cervix, the vaginal cuff and the parametria on both sides. The median follow-up time was 7-8 years. Statistical correlations were found between follow-up data, biometric morphologic criteria and survival. The statistical ranking of the significant prognostic factors produced the following order: lymph node metastases, size of lymph node metastases, tumour volume, parametrial involvement and vascular invasion.

Cell Differentiation↗

PubMed2003

Three-dimensional ultrasound in the assessment of normal fetal thigh volume.

Accurate assessment of the fetal organ volumes is very important in the evaluation of fetal well-being and maturation. Previous investigators have pointed out that fetal thigh volume (ThiV) may be a useful predictive factor of intrauterine growth retardation. Yet, 2-D ultrasound (US) is limited in assessing fetal ThiV accurately. With the recent advance of 3-D US, the limitation in assessing fetal ThiV by 2-D US can be overcome. To establish a normal reference chart of fetal ThiV for clinical use, a prospective and cross-sectional study using 3-D US was undertaken to assess the fetal ThiV in normal pregnancy. In total, 204 singleton fetuses ranging between 20 and 40 weeks of gestation and fitting the criteria of normal pregnancies were enrolled in this study. Our results showed that fetal ThiV is highly correlated with the gestational age (GA). Furthermore, using GA as the independent variable and ThiV as the dependent variable, the best-fit regression equation was ThiV (mL) = 35.494 - 4.985 x GA + 0.183 x GA(2) (r = 0.91, n = 204, p < 0.0001). For further clinical use, a chart of normal growth centiles of fetal ThiV was then calculated based on this equation. Furthermore, common indexes of fetal biometry, such as biparietal diameter (BPD), occipitofrontal diameter (OFD), head circumference (HC), abdominal circumference (AC), femur length (FL) and estimated fetal weight (EFW), were all highly correlated with ThiV (all p < 0.0001). In conclusion, our data of fetal ThiV assessed by 3-D US can serve as a useful reference in evaluating fetal growth and nutrition status during normal gestation.

Anthropometry↗

PubMed2003

The assessment of normal fetal liver volume by three-dimensional ultrasound.

Liver volume (LIVV) is very important in determining the status of fetal growth. However, to measure human fetal LIVV in utero precisely and noninvasively is not an easy task. With the recent advancement of three-dimensional (3-D) ultrasound (US), the limitation in assessing fetal LIVV by 2-D US can be overcome. The purpose of this study was to establish a normal reference chart of fetal LIVV for clinical use. A prospective and cross-sectional study using 3-D US was undertaken to assess the fetal LIVV in normal pregnancy. In total, 226 singleton fetuses ranging between 20 and 40 weeks of gestation and fitting the criteria of normal pregnancies were enrolled in this study. Our results showed that fetal LIVV is highly correlated with the gestational age (GA). Furthermore, using GA as the independent variable and fetal LIVV as the dependent variable, the best-fit regression equation was LIVV (mL) = -398.26 + 46.199 xGA - 1.7567 x GA(2) + 0.0236 x GA(3) (r = 0.97, n = 226, p < 0.0001), with SD of LIVV (mL) = 1.2533 x (0.77956 + 0.17267 x GA). These common indexes of fetal biometry, such as biparietal diameter (BPD), occipitofrontal diameter (OFD), head circumference (HCi), abdominal circumference (ACi), femur length (FL), and estimated fetal weight (EFW), were all highly correlated with fetal LIVV (all p < 0.0001). In conclusion, our data of fetal LIVV assessed by 3-D US can serve as a useful reference in evaluating fetal growth status during normal gestation.

Anthropometry↗

PubMed2003

The assessment of normal fetal brain volume by 3-D ultrasound.

The assessment of the fetal brain volume (BV) is very important in the evaluation of fetal growth. The purpose of this study is to use the three-dimensional (3-D) ultrasound (US) in constructing reference centiles of the fetal BV during normal gestation for clinical application. This study was undertaken by a prospective and cross-sectional design. In total, 203 singleton fetuses ranged between 20 and 40 weeks of gestation and fit the criteria of normal pregnancies were enrolled in this study. Our results showed that fetal BV is highly correlated with the gestational age (GA). Furthermore, using GA as the independent variable and the fetal BV as the dependent variable, the best-fit regression equation was BV (mL)=-171.48036+4.8079xGA+0.29521xGA2 (r=0.99, n=203, p<0.0001), with SD of BV (mL)=1.2533x(9.9474+0.07133xGA). In addition, the common growth parameters of the fetal biometry, such as biparietal diameter (BPD), occipitofrontal diameter (OFD), head circumference (HC), abdominal circumference (AC), femur length (FL) and estimated fetal weight (EFW), were all highly correlated with the fetal BV (all p<0.0001). In conclusion, our data on the fetal BV assessed by 3-D US may serve as a useful reference in evaluating fetal growth.

Anthropometry↗

PubMed2000

Surgical correction of severe myopia with an angle-supported phakic intraocular lens.

PURPOSE: To evaluate the effectiveness, predictability, and safety of a fourth-generation angle-supported anterior chamber phakic intraocular lens (IOL) in patients with severe myopia. SETTING: Refractive Surgery and Cornea Unit, Alicante Institute of Ophthalmology, Miguel Hernández University School of Medicine, Alicante, Spain. METHODS: In this prospective study, 23 eyes (16 patients) with a mean preoperative myopia of -19.56 diopters (D) +/- 1.76 (SD) (range -16.75 to -23.25 D) were implanted with the ZSAL-4 phakic IOL. Basic examinations were performed before and after surgery in all patients. Eighteen eyes were also studied by clinical specular microscopy, and the endothelium was analyzed for cell density, coefficient of variation in cell size, and hexagonality. The location of the IOL in the anterior chamber was evaluated in 10 eyes by A-scan biometry. To evaluate haptic geometry, a theoretical mechanical model was used. The follow-up was 24 months in all patients. RESULTS: Uncorrected visual acuity was 20/40 or better in 13 eyes (56.0%) 12 months after surgery and in 14 eyes (60.8%) at 24 months. Best spectacle-corrected visual acuity improved 0.19 at 12 and 24 months (0.1 = 1 line) from preoperative values. The efficacy index was 1.12 at 24 months and the safety index, 1.45. The mean postoperative spherical equivalent was -0.65 +/- 0.65 D at 24 months. The postoperative spherical equivalent was within +/-1.00 D of emmetropia in 19 eyes (82.6%) at 12 and 24 months. The mean endothelial cell loss was 3.50% at 12 months and 4.18% at 24 months. The coefficient of variation in cell size decreased from 0.34 before surgery to 0.28 at 24 months after surgery. The IOL was located 0.79 +/- 0.24 mm in front of the crystalline lens. Postoperative complications included night halos in 6 eyes (26.1%) at 12 and 24 months and pupil ovalization in 4 eyes (17.4%). Intraocular lens rotation was observed in 10 eyes (43.5%) at 24 months. Two eyes (8. 7%) developed a slight inflammatory response during the first 6 months. Our mechanical model predicted that the compression forces against the angle structures were greater at the first footplate than at the second. CONCLUSIONS: Implantation of the ZSAL-4 IOL in the anterior chamber of phakic eyes was effective and predictable in correcting severe myopia. However, the ZSAL-4 did not prevent pupil ovalization, IOL rotation, or low-grade postoperative uveitis. Improvements in haptic design following our mechanical model could decrease these haptic-related complications.

Adult↗

PubMed2002

Lensectomy in the management of glaucoma in spherophakia.

A 42-year-old woman presented with uncontrolled glaucoma despite patent peripheral iridotomies after a previous episode of acute angle-closure glaucoma. Spherophakia was diagnosed by anterior segment findings, refraction, A-scan biometry, and ultrasound biomicroscopy. Continuous curvilinear capsulorhexis, phacoemulsification, and infusion/aspiration were performed in the right eye. Attempted intraocular lens (IOL) implantation failed, and the eye was left aphakic. Six months later, the intraocular pressure (IOP) was normal without glaucoma therapy and visual acuity was 6/6 with a contact lens. The patient then had phacoemulsification in the left eye, removal of the capsular bag, anterior vitrectomy, and insertion of an anterior chamber IOL. Four months after surgery, the uncorrected visual acuity was 6/9 and the IOP was normal without glaucoma therapy.

Adult↗

PubMed2003

Clinical results of excimer laser photorefractive keratectomy for high myopic anisometropia in children: four-year follow-up.

PURPOSE: To evaluate the visual and refractive results of multizonal photorefractive keratectomy (PRK) for high myopic anisometropia and contact-lens intolerance in children. SETTING: Department of Ophthalmology, Masaryk University Hospital, Brno, Czech Republic. METHODS: Twenty-one patients aged 7 to 15 years with high myopic anisometropia had multizonal PRK in the more myopic eye and were retrospectively analyzed. The scanning-slit Nidek EC-5000 excimer laser was used. Postoperatively, patients were reviewed at 1 and 3 days, 1 week, and 1, 3, 6, 12, 18, 24, 36, and 48 months. The examination included cycloplegic refraction, uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), biomicroscopy, grading of postoperative haze, corneal topography, pachymetry, intraocular pressure, biometry, orthoptic status, binocular vision (BV), and fundus evaluation. The safety, efficacy, predictability, and stability of the procedure were evaluated. Long-term binocular vision outcome was analyzed. All patients completed a 4-year follow-up. RESULTS: The mean preoperative spherical equivalent (SE) refraction was 8.93 diopters (D) +/- 1.39 (SD) (range -6.75 to -11.75 D) and the mean postoperative SE, -1.66 +/- 0.68 D (range -0.50 to -2.75 D) (P <.05). The mean preoperative UCVA of 0.034 +/- 0.016 increased to 0.35 +/- 0.15 (P <.05) postoperatively. The mean preoperative BSCVA was 0.53 +/- 0.19 and changed to 0.64 +/- 0.16 postoperatively. The safety index was 1.21. No eye lost a line of BSCVA; 9 eyes gained 1 line, and 5 eyes gained 2 lines. The efficacy index was 0.66. The postoperative uncorrected and best spectacle-corrected BV were the same or improved. No eye had +3 haze. There were no significant complications. CONCLUSIONS: Photorefractive keratectomy was safe and effective in correcting high myopic anisometropia in children who were contact-lens intolerant. It provided good visual results and preserved or improved BV over the 4-year follow-up.

Adolescent↗

PubMed2004

Opposite clear corneal incisions on the steep meridian in phacoemulsification: early effects on the cornea.

PURPOSE: To evaluate the effect of on-axis opposite clear corneal incisions (OCCIs) in phacoemulsification on reducing preoperative corneal astigmatism and to predict the astigmatic outcome of the incisions. SETTING: Royal Eye Infirmary, Dorset County Hospital, and Winterbourne Hospital, Dorchester, Dorset, and the Department of Ophthalmology, East Somerset Hospital, Yeovil, Somerset, United Kingdom. METHODS: This prospective study included all patients (n = 103) who had on-axis OCCIs as a part of routine phacoemulsification with foldable intraocular lens (IOL) implantation performed by 1 surgeon during 2000. Keratometry was done 6 to 8 weeks postoperatively. The differences in the preoperative and postoperative corneal astigmatism and corneal spherical equivalent (SE) were recorded. Surgically induced astigmatism (SIA) was calculated using vector analysis. RESULTS: The mean reduction in corneal astigmatism was 0.50 diopter (D) (P<.001). The mean SIA was 1.57 D (95% confidence interval [CI], 1.42 to 1.71). There was a weak association between the SIA and the patient's age and axis of preoperative astigmatism. The mean change in SE was +0.02 D (95% CI, -0.08 to +0.12). CONCLUSIONS: Results indicate that on-axis OCCIs are a reliable and practical way of reducing preexisting corneal astigmatism. The change in SE was negligible and thus can be ignored during biometry.

Aged↗

PubMed1993

Restoring lens capsule integrity enhances lens regeneration in New Zealand albino rabbits and cats.

In studies conducted by numerous investigators for 150 years, lenses regenerated following endocapsular lens extraction in New Zealand albino rabbits have been irregular in shape, appearing primarily doughnut-shaped as a result of lack of lens growth at the site of the anterior capsulotomy and its adhesion to the posterior capsule. In the present study, we restored the lens capsule integrity by inserting a collagen patch at the time of surgery to seal the anterior capsulotomy and to improve the shape and structure of the regenerated lenses. We then filled the capsule bag with air to prevent adhesions between the anterior and posterior capsule and maintain capsule tautness and shape. Lens regeneration was first noted as early as one to two weeks. Regenerated lens filled approximately 50% of the capsule bag at two weeks and 100% by five weeks. Subsequent growth was in the anterior-posterior direction and measured by A-scan biometry. Lens thickness increased by 0.3 mm per month. The regenerated lenses were spherical with normal cortical structure and a nuclear opacity. In conclusion, restoration of lens capsular integrity with a collagen patch following endocapsular lens extraction enhanced the shape, structure, and growth rate of the regenerated lenses. In addition, lens regeneration was shown to occur in two cats.

Air↗

PubMed1988

Calculating axial length in the aphakic and the pseudophakic eye.

The axial length of 149 eyes (84 pseudophakic and 65 aphakic) was calculated by refractive means and compared with the axial length determined by ultrasound. The mean error (+/- SD) between the measured and the calculated axial length (measured minus calculated) was 0.02 mm (+/- 0.51) and 0.13 mm (+/- 0.54) for the aphakic and the pseudophakic eyes, respectively. The mean error was not significantly different from zero (P greater than .05). Calculation of the axial length may represent a valuable alternative to biometry for the aphakic and the pseudophakic eye.

Aged↗

PubMed1989

Measurement of postoperative intraocular lens tilting and decentration using Scheimpflug images.

A three-dimensional, in vivo method for determining the position of implanted intraocular lenses (IOLs) using an image-processing technique has been developed. Two images of the anterior segment of the eye with an implanted IOL were photographed with a Scheimpflug camera at slit-lamp angles of 90 degrees and 180 degrees. After geometrical correction, the contours of the original images were enhanced using binarization and curve-fitting techniques. These images afforded calculation of the angle of tilt of the IOL optic axis relative to a standard reference line which connected the center of anterior corneal surface curvature with the geometrical center of the pupil. The extent and direction of IOL decentration could also be shown. The IOL image in the posterior chamber was expressed as a wire-frame figure. This method provides several kinds of biometry in pseudophakic eyes.

Anterior Eye Segment↗

PubMed1998

Staar Collamer posterior chamber phakic intraocular lens to correct myopia and hyperopia.

PURPOSE: To evaluate the efficacy, safety, stability, and predictability of implanting a collagen polymer (Staar Collamer), posterior chamber phakic intraocular lens (IOL) to correct myopia and hyperopia. SETTING: Centre for Advanced Refractive Eye Surgery at the BMI Alexandra Hospital, Cheadle, Manchester, United Kingdom. METHODS: A Staar Collamer posterior chamber phakic IOL was implanted in 25 eyes of 14 patients with a mean age of 37.9 years (range 20 to 50 years). Seven patients were men and seven, women. Sixteen were myopic and 9, hyperopic. Before treatment, each patient had a thorough evaluation including refractive, general, ocular, and social and personal histories. The examination included visual acuity, refraction, tonometry, topography, biometry, biomicroscopy, pupil size in dim illumination, and posterior segment evaluation by a vitreoretinal specialist. Patients were informed about the surgical process and expected outcome, their own expectations were discussed, and their consent to surgery was obtained. Surgical implantation was performed through a less than 3.0 mm clear corneal sutureless incision using brief general anesthesia on a day-case surgical basis. RESULTS: At 3 months postoperatively, all eyes had a significant increase in uncorrected visual acuity, allowing all but two patients (three eyes) to manage most activities without spectacles. Adjustment by incisional corneal surgery was planned for undercorrected myopic eyes (n = 3). Pupil block glaucoma and pigment deposits occurred in one patient each. CONCLUSION: In this short-term study, the posterior chamber phakic IOL was predictable, safe, and efficacious in the correction of myopic and hyperopic refractive errors, with good refractive stability. Long-term follow-up is required to validate that the absence of significant complications in most patients is a lasting phenomenon.

Adult↗

PubMed2004

Optical coherence tomography of the anterior segment of the eye.

Optical coherence tomography is a versatile tool for visualization and measurement of corneal and anterior segment anatomy. Keratorefractive surgery, anterior chamber biometry, and angle assessment are some of the applications that should benefit from this technology.

Anterior Eye Segment↗

PubMed2003

Heart and blood pressure adaptations in Wistar rats fed with different high-fat diets for 18 months.

OBJECTIVE: We investigated the effect of long-term administration of four different high-fat diets on systolic blood pressure (SBP), body and heart biometry, and left ventricular myocyte nuclei number (N[lvm]). METHODS: Twenty-four Wistar rats were assigned to one of four groups from weaning to age 18 mo. The rats were fed experimental diets containing soybean oil (S group), canola oil (CA group), lard and egg yolk (LE group), and canola oil plus lard and egg yolk (CA + LE group). N(lvm) was measured with the disector method in isotropic uniform random sections of the left ventricular myocardium. RESULTS: There were no significant differences across experimental groups in morphometric indices. SBP was higher in the LE group at all ages and lower in the 18-mo CA group. The myocardium structure analysis separated the animals in three major categories: the CA and LE groups as the extreme and the S and CA + LE groups as the intermediary. In the LE group the myocardium presented more important structural changes: cardiac myocytes were enlarged and surrounded with thick collagen bundles, and some regions exhibited myocardial necrosis. CONCLUSION: Long-term intake of the CA diet was more efficient in maintaining normal N(lvm) and SBP than the S and LE diets. The CA + LE diet resulted in balanced levels of SBP and N(lvm) in rats, suggesting that canola oil reduces cardiovascular injury caused by intake of lard and egg yolk.

Adaptation, Physiological↗

PubMed2000

[Does neonatal screening of cystic fibrosis affect outcome? Comparative study of two cohorts in Britanny and Loire-Atlantique with follow-up after ten years].

UNLABELLED: Neonatal screening for cystic fibrosis was started in Brittany in 1989 but not in the adjacent department of Loire-Atlantique. This study compares the outcome from the children of both populations nine years after the beginning of the screening. Those children were seen in different centers but with the same following guidelines. POPULATION AND METHODS: All children with cystic fibrosis born between 01/01/89 and 31/12/97 in Brittany and the Loire-Atlantique, excluding the meconium ileus, were compared for their initial characteristics and their outcome after nine years of follow-up. RESULTS: There was no significant difference between both populations for sex ratio, gestational age, birth biometry, percentage of homozygotes delta F508, and mean age of children. Age at diagnosis was lower in Brittany (37 vs 372 days, P < 10(-7)), as was the delay for starting pancreatic supplementation (1.5 vs 14.3 months, P < 10(-7)). Percentage of children hospitalized at least once was higher in Loire-Atlantique (84.4 vs 40.3%, P < 10(-4)). There was no significant difference for colonization with Pseudomonas aeruginosa. Z-scores for weight and height were better in Brittany, as were Shwachman's and Brasfield's scores. CONCLUSION: The homogeneity of both populations and their follow-up points out that even if the numbers of children are small and the study is retrospective, some benefits of neonatal screening appear, which are already found in other countries where it is partly practiced. This leads us recommend its general use in our populations, which should be associated with the follow-up of the screened children in cystic fibrosis centers to achieve the most of its benefits.

Adolescent↗

PubMed1988

Prognostic factors in cervical cancer on the basis of morphometric evaluation.

As for all tumours, the most important prognostic factors in cervical cancer are growth pattern and the extent of its spread. The systematic study of serial giant sections of specimens obtained at radical hysterectomy has made these morphological factors assessable by biometry. Statistical analysis produced the following ranking of prognostic factors in cervical cancer: the size of the primary tumour, lymph node involvement, infiltration of the connective tissue layer between cervix and parametrium, exophytic growth, parametrial invasion, and mitotic rate. These factors can be used in a biomathematical model to exclude or predict tumour recurrence or death from disease.

Female↗