[The cornea in high axial myopia]. / Cornée et myopie axile forte.

PURPOSE: To compare corneal characteristics of eyes with high myopia with those of eyes with no spherical ametropia using Orbscan and ultrasonic pachymetry. METHODS: Orbscan and ultrasonic pachymetry values were prospectively recorded in a study group of 105 patients with high myopia (i.e., axial length greater than 26mm in both eyes) and in a control group of 105 patients with no spherical ametropia (absolute value of spherical equivalent less than 1.25D regardless of cylinder value). Astigmatism data were expressed by rectangular coordinates in a dioptric plane. Axis was decomposed in 2 components (WTR/ATR and oblique) which were analyzed by Cos2axis and Sin2axis trigonometric functions. Enantiomorphism (mirror-image symmetry) between fellow eyes was quantified by a Euclidean distance for the location of the thinnest point and by the difference (in absolute value) between 180° and the sum of both axes for astigmatism. RESULTS: In the study group, the mean axial length and subjective spherical equivalent were, respectively, 27.82±2.14mm (26.00 to 34.06) and -9.00±3.46D (-4.71 to -19.82). The mean corneal astigmatism was +0.92D×91.3° in the study group and +0.65D×89.3° in the control group. The mean corneal cylinder was higher in the study group (1.44D versus 0.91D; P<0.001) whereas axis showed no significant differences between both groups. The mean maximal keratometry was steeper in the study group (44.53D versus 44.13D; P=0.03) whereas the mean keratometry and minimal keratometry displayed no significant differences between both groups. No significant differences in central corneal thickness (540.2µm versus 546.9µm; P=0.10), peripheral corneal thickness, corneal diameter, corneal irregularity, asphericity, and irregular astigmatism were found between both groups. There were no significant differences in enantiomorphism parameters between both groups. In the study group, correlation with axial length was significant only for spherical equivalent (r=-0.86; P<0.001) and corneal cylinder (r=0.16; P=0.04). CONCLUSION: High myopia exhibits corneal characteristics similar to corneas of eyes with no spherical ametropia, except for toricity. While the posterior segment elongates, development of high myopia appears not to affect corneal characteristics. Corneal toricity may be associated with evolution toward high myopia by perturbing mechanisms of emmetropization.

Translation in Arabic, adaptation and validation of the SF-36 Health Survey for use in Tunisia.

OBJECTIVE: To translate into Arabic and validate the SF-36 quality of life index in a Tunisian Arabic population. BACKGROUND: No validated Arabic quality of life index is published. DESIGN: Arabic translation of the SF-36 scale was obtained by the "forward/backward translation" method. Adaptations were made after a pilot study involving 22 subjects from general population. Inter-rater reliability was assessed by use of intraclass correlation coefficient (ICC) and Bland and Altman method. Construct validity was assessed by Spearman rank correlation coefficient (convergent and divergent validity), and factor analysis with Varimax rotation. Internal consistency was assessed by Cronbach alpha coefficient. RESULTS: We note that 130 Tunisian subjects were included in the validation study. No items were excluded. Inter-rater reliability was excellent (ICC=0.98). Cronbach alpha coefficient was 0.94 conferring to translated index a good internal consistency. Expected divergent and convergent validity results suggested good construct validity. Two main factors were extracted by factor analysis and explained 62.3% of the cumulative variance: the first factor represented mental component, the second physical component. The Cronbach alpha coefficient was 0.88 and 0.91 respectively for factor 1 and factor 2. CONCLUSION: We translated into Arabic language and adapted the SF-36 scale for use in Tunisian population. The Arabic version is reliable and valid. Although the scale was validated in a Tunisian population, we expect that it is suitable for other Arab populations, especially North Africans. Further studies are needed to confirm such a hypothesis.

[Relationships between refractive parameters: sphere, cylinder and axis]. / Relations entre les paramètres de la réfraction : sphère, cylindre et axe.

PURPOSE: To analyze the relationships between refractive parameters as well as the relationship between fellow eyes in a normal population. METHODS: Both subjective refraction and auto-refractometry data of 500 patients were prospectively recorded. Refraction data were analyzed on three rectangular coordinates in a dioptric space. WTR/ATR ratio of axis was quantified by the Cos2axis function. Enantiomorphism (mirror-image symmetry) between fellow eye axes was quantified by the absolute value of the difference between 180° and the sum of both axes. RESULTS: Mean refraction and mean cylinder were -1.74D (+0.28D × 91.5°) and 0.81 ± 0.89D respectively. The spherical component had no significant influence on refractive astigmatism (r(s)≤ 0.07, P ≥ 0.07) except for high spherical ametropia. Eyes with spherical equivalent greater than 4D (in absolute value) demonstrated higher cylinder (1.15D vs 0.84D, P<0.001). Cylinder influenced the WTR/ATR ratio (r(s)=-0.25, P<0.001) and the enantiomorphism (r(s)=0.36, P<0.001). Age also influenced the WTR/ATR ratio (r(s)=0.27, P<0.001) and the enantiomorphism (r(s)=0.14, P<0.001). Axes were more likely WTR and enantiomorphic when the cylinder was high and the subject young. Oblique axes were less enantiomorphic (35.5° vs 20.6°, P<0.001) and were associated with lower cylinder (0.56D vs 0.98D, P<0.001). Correlation between fellow eyes was significant for cylinder (r(s)=0.66, P<0.001) and for spherical equivalent (r(s)=0.96, P<0.001). Gender had no significant influence on refraction (P>0.12) except for spherical equivalent (relative hyperopia of +0.17D, P=0.04 in females). CONCLUSION: The spherical component of the refraction appears to be independent of the refractive astigmatism except for high spherical ametropia. Cylinder influences somewhat the WTR/ATR ratio of axis and the enantiomorphism. Relationships between refractive parameters are weak in comparison to the fellow eye relationships.

New test for the diagnosis of bacterial endophthalmitis.

BACKGROUND: Diagnosis of bacterial endophthalmitis (BE) often fails due to: (1) insufficient volumes of vitreous fluid (VF) and aqueous humour (AH); (2) lack of sensitivity of culture; (3) antibiotic treatments; (4) polymerase chain reaction (PCR) cross-contamination; and (5) limitations on the interpretation of the real-time PCR melting curve. We developed a fast real-time (f-real-t) PCR to improve the performance of the laboratory diagnosis of BE. METHODS: The following samples were processed after adding an internal control: phosphate buffered saline (PBS); VF, AH and cell suspensions spiked with Bacteria (Bac); VF and AH from patients with endophthalmitis; and VF and AH from non-infective patients. DNA was extracted (MagNA Pure) and added to four tubes containing selected primers and probes for the identification and quantification of all Bac and eight genera by f-real-t PCR. Diagnostic performances based on direct microscopic examination, culture and f-real-t PCR were compared. RESULTS: The f-real-t PCR detected at least 0.01 colony-forming units (CFU) of Bac/microl with no cross-reactivity with fungi. Correlation with culture-positive results was 100%. Sixty per cent of BE samples tested culture-positive, but f-real-t PCR tested positive for 90%. Samples from non-infective cases were negative. CONCLUSION: The f-real-t PCR detected and quantified Bac, Staphylococci, Streptococci, Haemophilus, Pseudomonas, Enterobacteria, Acinetobacter, Propionibacteriacae and Corynebacteria in one run. Cultures required several hours to days (with a non-negligible number of false-negative results) and the f-real-t PCR was completed in 90 min. The f-real-t PCR is presented as a new tool for the diagnosis of BE: its usefulness requires validation with larger series of samples.

[Ocular response analyzer: feasibility study and correlation with normal eyes]. / Ocular response analyzer : étude de fiabilité et de corrélation sur des yeux normaux.

INTRODUCTION: To evaluate the accuracy of ocular response analyzer (ORA) parameters (corneal hysteresis (CH), corneal resistance factor (CRF), and ocular tension (IOPcc and IOPg)) and the correlation with corneal biometry measured with the Orbscan topographer. MATERIAL: and methods: The Ocular Response Analyzer is a new instrument that measures ocular rigidity/elasticity (CH and CRF) and intraocular pressure (IOPcc), which is assumed to be independent of corneal pachymetry. We compared the results of the ORA in 100 eyes with normal slit lamp examination, except ametropia, with the results from corneal measurements obtained with the Orbscan. RESULTS: A high correlation and a low difference between the right and left eyes show the accuracy of measurements (rS=0.84, p<0.001 and 8.52%). The mean CH and CRF were 10.25+/-1.6 mmHg (range, 6.5-14.4) and 10.25+/-1.85 mmHg (range, 4.9-14.2), respectively with a Gaussian distribution in normal eyes. The relationship between CH and CRF was significant with corneal pachymetry but not with IOPcc (corneal corrected). CH and CRF were related, although to a lesser extent, with corneal diameter and astigmatism power, but not to keratometry, sex, age, or spherical equivalent. CONCLUSION: The mean and the distribution of biomechanical factors are similar to the values found in the literature but the relationship to pachymetry seems to be stronger (pachymetry and corneal diameter) than what has been reported in previous publications. The new IOP corrected for the cornea is independent of pachymetry but is not significantly different from Goldmann IOP or IOP measured with a standard noncontact tonometer.

[Advantages of the autorefractometer and the Orbscan for measuring pupil diameter]. / Intérêt de l'auto-réfractomètre et de l'Orbscan pour la mesure du diamètre pupillaire.

PURPOSE: We compared pupil size measurements obtained with the Orbscan and autorefractometer to the Colvard Infrared pupillometer in order to determine their respective clinical advantages. MATERIAL AND METHODS: We prospectively measured the pupil diameter in 94 eyes of 47 normal patients using the Colvard device, the Nikon NKR 8000 autorefractometer, and the Orbscan device. For each device, two successive measurements were taken to determine its reproducibility. We also studied the relationship with the contralateral eye (i.e., difference and correlation). The measurements obtained with the different devices in different light intensities were compared and studied using regression analysis. RESULTS: Pupil diameter measured using the Orbscan had the highest reproducibility (mean difference between the two successive measurements: 3.8% or 0.15mm) and showed the smallest difference between the two eyes (5.0% or 0.19mm) and the strongest correlation with the contralateral eye (r=0.93; p<0.001). Scotopic Colvard measurements and autorefractometer measurements with low light settings were not significantly different (5.86mm versus 5.86mm; p=0.48). Autorefractometer measurements with low light settings showed the strongest correlation with the scotopic Colvard measurements (r=0.84; p<0.001). The Orbscan measurements were less correlated with the scotopic or photopic Colvard measurements (r=0.73; p<0.001 and r=0.51; p=0.003, respectively). For the Colvard pupillometer, the correlation between photopic measurements and scotopic measurements was also poor (r=0.51; p<0.001). CONCLUSION: Pupil size measurements with the autorefractometer may be advantageous before refractive surgery. Measuring pupil size in photopic conditions, as with the Orbscan, cannot screen people with large pupils in mesopic conditions.

[Ocular biometry using Orbscan]. / Biométrie oculaire par Orbscan.

Orbscan is a recent optical device that combines the Placido disk of the videokeratoscope and a scanning slit. The scanning slit measures the elevation of both the corneal surface (anterior and posterior) and the anterior iris-lens surface. Biometric measures of the anterior segment such as corneal thickness, anterior chamber depth, corneal diameter, and iridocorneal angle are obtained using spatial coordinates of various ocular surfaces. Orbscan is not only a corneal topograph but a versatile device capable of measuring the biometry of the anterior segment of the eye.

[Crystalline lens biometry using A-scan ultrasound and the Orbscan device]. / Etude biométrique du cristallin par échographie A et Orbscan.

PURPOSE: To analyze the lens biometry obtained by Orbscan and A-scan ultrasound in normal eyes. MATERIAL: and methods: The lens thickness obtained by A-scan ultrasound and the anterior curvature of the crystalline lens obtained by Orbscan were prospectively recorded in 280 normal eyes (including eyes with ametropia) of 140 patients (10-95 years of age). The correlation of lens biometry with the contralateral measure, patient age and sex, subjective refraction, and other ocular biometric parameters (anterior chamber depth, iridocorneal angle, corneal diameter, central pachymetry, pupil, corneal radii of curvature, and posterior segment length) was assessed. RESULTS: The lens anterior curvature showed no significant correlation in particular with the subjective spherical equivalent; however, the quality of this measure was poor: the reproducibility of the lens anterior curvature was low (the average difference between two successive Orbscan measurements was 14.4%). The correlation with the contralateral eye was poor (rs=0.55; p<0.001 versus rs=0.97; p<0.001 for lens thickness). Lens thickness showed the strongest correlation with the patient's age (rs=0.82; p<0.001); it increased by 0.26 mm per decade. Lens thickness correlated with anterior chamber depth (rs=-0.72; p<0.001) and iridocorneal angle (rs=-0.65; p<0.001). The last two parameters also correlated with age (rs=-0.68; p<0.001 and rs=-0.62; p<0.001, respectively). Anterior chamber depth and iridocorneal angle decreased by -0.21 mm and -1.7 degrees , respectively, per decade. CONCLUSION: Lens thickness is mainly influenced by age and correlates with the anterior chamber depth and the iridocorneal angle. The influence of aging on anterior segment biometry essentially consists in an increase in lens volume.

[The relationship between keratoconus and axial myopia]. / Relation entre le kératocône et la myopie axile.

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.

[Biometric study of acute-angle-closure glaucoma using Orbscan and echography]. / Analyse biométrique par Orbscan et échographie du glaucome aigu par fermeture de l'angle.

PURPOSE: To study acute-angle-closure glaucoma (AACG) biometry using Orbscan and echography. MATERIAL AND METHODS: We prospectively studied 200 normal eyes of 100 patients (including eyes with ametropia), 50 eyes of 25 patients before peripherial YAG laser iridotomy, 25 phakic eyes of 25 patients with a history of acute-angle-closure glaucoma (AACG) in the fellow eye. Both plane and polynomial modes of reconstruction of the iridocorneal angle measurement were analyzed. Biometric measurements of the three groups were compared. Biometric measurements (i.e., iridocorneal angle, anterior chamber depth, axial length, and lens thickness) and subjective spherical equivalent were correlated with the etiological classification. RESULTS: Age, sex, iridocorneal angle, anterior chamber depth, lens thickness, axial length and subjective spherical equivalent were significantly different in the three groups (p<0.002). The polynomial iridocorneal angle measurement was 43.4 degrees in the normal group, 36.5 degrees in the iridotomy group, and 28.4 degrees in the AACG group (p<0.001). Iridocorneal angle measurement correlated with the other biometric measurements (rs>0.51; p<0.001) and with the etiological classification (rs< or =0.68; p<0.001). The anterior chamber depth measurement obtained by Orbscan or echography was the best parameter for predicting ACCG (rs=0.77; p<0.001). CONCLUSION: The anterior chamber depth and polynimial iridocorneal angle obtained using the Orbscan device appears to be useful in predicting acute-angle-closure glaucoma.

[Treatment of the sequelae of ocular burns using limbal transplantation]. / Traitement des séquelles de brûlures oculaires par la greffe de limbe.

PURPOSE: To report the results of limbal transplantation in patients with severe ocular burns and limbal stem cell deficiency. PATIENTS AND METHODS: This series includes six autografts (unilateral ocular burns) and five allografts (bilateral ocular burns) performed in ten eyes of ten males with an average age of 43 years. The origin of the ocular burn was chemical in eight cases and thermal in the remaining two cases. The average time between the initial trauma and limbal transplantation was 79 months. The average size of limbal grafts was 190 degrees (range: 80-20 degrees for autografts and 120-360 degrees for allografts). Patients with allografts received oral cyclosporine in three cases, topical cyclosporine in one case, and intravenous methylprednisolone in one case. Eight patients underwent penetrating keratoplasty an average of 11 months after limbal transplantation (range: 5-24 months). RESULTS: The average follow-up time was 36 months (range: 7-77 months). The overall success rate of limbal transplantation (ocular surface improvement) was 73% (8/11). The success rate of penetrating keratoplasty was 63% (5/8). The average initial visual acuity was 0.4/10 and the average final visual acuity was 1.6/10. Visual acuity improved by two lines or more in seven cases. DISCUSSION: Limbal transplantation is a useful surgical technique in patients with severe ocular burns. However, results remain insufficient and new techniques such as limbal stem cell culture and transplantation are needed to improve the visual prognosis of these patients.

[Incidence and factors influencing glaucoma after penetrating keratoplasty]. / Incidence et facteurs de risque de l'hypertonie oculaire au cours des kératoplasties transfixiantes.

PURPOSE: To determine the incidence and factors influencing glaucoma following penetrating keratoplasty. MATERIAL AND METHOD: We prospectively studied 440 consecutive patients undergoing penetrating keratoplasty over a period of 5 years, with an average follow-up of 2 years. High intraocular pressure was defined as IOP over 20 mmHg measured by Goldmann applanation for at least 1 week or if a patient required topical treatment for at least 1 week. Before surgery, 18.7% of the patients presented with glaucoma or high intraocular pressure; 44.9% received a graft for a bullous keratopathy condition, 25.6% had keratoconus, 31.5% received an anterior chamber lens, and 48.5% were phakic. RESULTS: After surgery, 42.2% of the patients had ocular pressure at 20 mmHg or more and required treatment for high ocular pressure. The increase in intraocular pressure appeared after an average delay of 3.3 +/- 4.7 months. The frequency of the increase in intraocular pressure was 54.3% for the bullous keratopathy patients, 26.6% for the keratoconus patients (p<0.001). At the end of the second year, the graft survival was 82.1% in absence of glaucoma, whereas it was 71.5% in cases of glaucoma after keratoplasty. Between all parameters that we studied, high intraocular pressure before surgery, etiology, the status, and receiver age over 60 years were the main factors influencing high intraocular pressure after keratoplasty. Intraocular pressure was correlated with the decrease in endothelial cell density and was at the origin of graft failure. Intraocular pressure correlated with the Best Spectacle Corrected Visual Acuity (BSCVA) by its effect on endothelial cell density and optic nerve destruction. CONCLUSION: The increase in intraocular pressure is a real and serious complication of keratoplasty. Its physiopathology is very complex. Better knowledge of risk factors can be useful in controlling it.

[Correlation between refraction and ocular biometry]. / Corrélation entre la réfraction et la biométrie oculaire.

PURPOSE: To study the correlation between subjective refraction and biometry obtained by Orbscan and echography in normal eyes. To compare biometric parameters with the subjective spherical equivalent. MATERIAL AND METHODS: Subjective refraction, biometric parameters using Orbscan, and echography were recorded in 190 normal eyes (including eyes with ametropia) of 95 patients. Biometric parameters (i.e., corneal diameter, anterior chamber depth, central pachymetry, iridocorneal angle, corneal and lens radii of curvature, and axial length of the eye) were compared in different refractive groups and were correlated with the subjective refraction. RESULTS: Corneal biometric parameters did not correlate with the subjective spherical equivalent and showed no differences between the refractive groups except for the central pachymetry. In the high myopic group (<-6D), the central cornea was significantly thinner (531 micro m versus 549 micro m, p=0.016). The correlation between corneal radius and axial length was strong in emmetropic eyes (r(s)=0.63, p<0.001) and poor but significant in ametropic eyes (r(s)=0.28, p=0.002). Axial length, anterior chamber depth, and iridocorneal angle showed significant differences between the refractive groups (p<0.001) and correlated with the subjective spherical equivalent (r(s[[/INF=0.44, p<0.001). Subjective spherical equivalent showed the strongest correlation with the axial length (rs)=0.82, p<0.001). Subjective spherical equivalent, central corneal thickness, axial length, anterior chamber depth, and anterior corneal radius showed a strong correlation between both eyes (rs[[/INF=0.94, p<0.001). CONCLUSION: Biometric characteristics of the eye (excluding cornea characteristics) vary with subjective spherical equivalent. Axial length presents the strongest correlation with the subjective spherical equivalent and correlates with the other ocular biometric parameters. Axial length plays a major role in the ocular biometry and refraction.

[Long-term refractive and topographic changes after penetrating keratoplasty]. / Variations réfractives et topographiques à long terme des kératoplasties transfixiantes.

PURPOSE: To analyze long-term refractive and videokeratoscopic changes after penetrating keratoplasty. PATIENTS AND METHODS: Forty eyes of 40 patients (26 keratoconus) with a clear corneal graft and no other ocular disease were examined after all sutures were removed, respectively at 22.0+/-7.3 months and 50.5+/-13.6 months after keratoplasty. All of the eyes were examined using videokeratography (EyeSys 2000) and ultrasonic pachymetry. Changes in subjective refraction, best spectacle-corrected visual acuity (LogMAR units), topography, and central corneal thickness between both exams were recorded. RESULTS: Visual acuity increased by an average of 0.41 lines +/-0.24 (p<0.001) between both exams, whereas no significant change in refractive astigmatism and videokeratoscopy (i.e., power, pattern, and indices) was observed. Central corneal thickness significantly increased from 545+/-36 micro m to 574+/-40 micro m (p<0.001). Change in best spectacle-corrected visual acuity significantly correlated with delay between the exams (r(s)=+0.34, p=0.03), whereas change in refractive astigmatism, topographic indices, and topographic patterns did not significantly correlate with delay. CONCLUSION: After penetrating keratoplasty, visual acuity improves long after surgery, whereas refraction and corneal surface regularity show no significant modification. This improvement in visual acuity, not explained by current techniques, may be due to an increase in graft transparency.

[Orbscan: a new device for iridocorneal angle measurement]. / L'Orbscan: un nouvel outil pour évaluer l'angle irido-cornéen.

PURPOSE: To evaluate the accuracy and reproducibility of iridocorneal angle measurement obtained with a slit-lamp method (Orbscan). METHODS: The iridocorneal angle was measured in 100 normal eyes of 50 patients using the Orbscan II device. Angles were measured in eight meridians using both the "plane" and "polynomial" modes. For each eye, two exams were taken successively and the reproducibility was calculated by analyzing the difference between both measurements. Angle value was correlated with subjective spherical equivalent and other biometric measurements obtained by Orbscan (i.e., anterior chamber depth, axial length, corneal diameter). RESULTS: Reproducibility of the angle measurement was significantly better with the plane mode than with the polynomial mode (5.4%+/-4.7 versus 7.2%+/-6.2; p<0.001). Reproducibility significantly varied with localization (p<0.001). Significant differences were found between reconstruction modes (49.3 degrees +/-4.6 degrees for plane mode versus 42.8 degrees +/-6.7 degrees for the polynomial mode; p<0.001) and according to localization (p=0.02). Correlation with the other biometric measurements was higher for the plane mode than for the polynomial mode. Angle measurement with the plane mode showed significant correlation with subjective spherical equivalent (r(s)=-0.59; p<0.001), the anterior chamber depth measurement (r(s)=-0.74; p<0.001), the axial length measurement (r(s)=-0.34; p<0.002), and the corneal diameter measurement (r(s)=-0.34; p<0.002). CONCLUSION: The iridocorneal angle measure obtained with the plane mode showed high reproducibility and it significantly correlated with clinical parameters. It appears to be useful for clinical application.

Down's syndrome screening with nuchal translucency at 12(+0)-14(+0) weeks and maternal serum markers at 14(+1)-17(+0) weeks: a prospective study.

BACKGROUND: Sonographic and biochemical methods for Down's syndrome screening have developed simultaneously, but independently. As a consequence, the rate of invasive procedures for fetal karyotyping has dramatically increased and become an important public health issue which needs to be controlled. One approach is to combine sonographic and biochemical results into a single risk assessment. METHODS: In a multicentre interventional study, nuchal translucency (NT) was measured between 12(+0) and 14(+0) weeks of gestation. Maternal serum markers (MSM) were measured between 14(+1) and 17(+0) weeks of gestation. Karyotyping was advised when: (i) NT was > or =3 mm; or (ii) the MSM-related risk was > or =1 in 250 at term. Karyotyping was delayed until after a maternal blood sample had been taken. NT and MSM were expressed as multiples of the medians (MoMs), and risks were calculated and tailored to the study population. A combined risk for NT and MSM was estimated retrospectively. Costs per case diagnosed, and the cost per case averted were calculated for the three screening strategies. RESULTS: A total of 9444 women was screened. Twenty-one fetuses (0.22%) had Down's syndrome, whilst 326 women (3.4%) were lost to follow-up. Among 9118 women followed up, 5506 had both NT and MSM, 821 had only NT, and 2791 had only MSM. Median maternal age was 30.5 years. False-positive rates for NT, MSM and NT combined with MSM were 3.0, 5.8 and 0.23% respectively. The false-positive rate generated by a sequential two-stage screening was 8.6%. Detection rates of Down's syndrome were 62 and 55% for NT and MSM respectively. Seven cases with Down's syndrome (35%) had raised NT and MSM, and 17 (81%) had either raised NT, MSM, or both. For a 5% false-positive rate, detection rates were 55 and 80% for NT alone and for combined NT and MSM respectively. Ultrasound alone appears to be more cost-effective ( pound50 per case diagnosed) than both tests ( pound61 per case diagnosed). CONCLUSIONS: The study results suggest a 25% increase in the detection rate of Down's syndrome using a combination of NT measurement at 12(+0)-14(+0) weeks and MSM at 14(+1)-17(+0) weeks for a 5% false-positive rate, with modest increase in cost.

[Amniotic membrane transplantation in severe corneal epithelial diseases. Preliminary results]. / Greffe de membrane amniotique dans les pathologies sévères de l'épithélium cornéen.

PURPOSE: To evaluate amniotic membrane transplantation (AMT) in severe corneal epithelial diseases. METHODS: Amniotic membrane transplantation was performed in 14 eyes of 14 patients from four groups: A, five severe ocular burns; B, four cases of cicatricial keratoconjunctivitis; C, three persistent epithelial defects after penetrating keratoplasty; D, two cases of pseudophakic bullous keratopathy. Five patients underwent AMT alone; two patients underwent AMT combined with limbal transplantation; the other three patients had limbal transplantation performed before AMT. Eight patients required combined penetrating keratoplasty. Patients with corneal stable reepithelialization, no corneal neovascularization, and no recurrence of the initial pathology were considered successful. RESULTS: The mean follow-up was 7+/-3 months. All but three patients underwent corneal reepithelialization within 6 weeks of AMT, with a mean healing time of 31+/-23 days. The success rate was 75% at 6 months (Kaplan-Meier method). Three of four procedures in group B failed. In eight patients, visual acuity improved, in one it worsened, and in the last five patients it remained unchanged. Visual acuity increased by an average of 7+/-9 lines. CONCLUSION: AMT is a useful technique for ocular surface reconstruction, especially in association with limbal transplantation. It could also improve the prognosis of penetrating keratoplasty in patients with severe corneal conditions.

[Change in refraction and topography after penetrating keratoplasty suture removal]. / Modifications réfractives et topographiques induites par l'ablation des sutures des kératoplasties transfixiantes.

PURPOSE: To study the refractive and topographic modifications induced by penetrating keratoplasty suture removal. METHODS: We prospectively studied 80 corneas from 80 patients who had undergone penetrating keratoplasty. All of the eyes were examined before and after all sutures were removed, respectively at 10.9 5.1 months and 21.5 9.6 months after keratoplasty. Subjective refraction, best spectacle-corrected visual acuity (LogMAR units), keratometry, and corneal topography using the EyeSys 2000((R)) device (axial tangential and refractive power) were recorded. Topographies were classified according to the pattern (Bogan classification) and the asphericity shape (prolate and oblate). RESULTS: Best spectacle-corrected visual acuity (Log MAR units) increased significantly after suture removal (1.1 1.9 lines, plt; 0.001). Suture removal decreased the subjective cylinder (5.01 D 2.06 with suture, 4.11 2.08 without suture; p=0.009). The change in subjective cylinder correlated with the change in topographic pattern(s)=0.67 p<0.001). Conversely to the "bow tie" patterns, the other topographic patterns were more frequent after suture removal. The change in visual acuity was essentially explained by the change in subjective cylinder(s)=0.40 p=0.002). The average central corneal power decreased significantly after suture removal by 0.83 to 1.81 D (p<0.001), whereas the subjective spherical equivalent increased (hyperopization) (-4.07D 3.73 with suture, -3.48 3.40 without suture; p=0.02). The change in central corneal power significantly correlated with the change in subjective spherical equivalent (r(s)()>0.30 plt; 0.001). The corneal power of the mid-periphery did not significantly change after suture removal. Suture removal significantly modified the asphericity shape distribution. (majority of prolate shape with suture, majority of oblate shape without suture, p<0.001). CONCLUSION: Keratoplasty sutures induce a central bulge in the corneal graft. Suture removal induces a decrease in the subjective cylinder and it increases the subjective spherical equivalent (hyperopization) through a decrease in the central corneal power. Suture removal modifies the corneal topographic pattern and shape. Visual acuity improvement after suture removal is mainly explained by the decrease in subjective astigmatism.

[Ocular biometric measurements with a slit-lamp method (Orbscan)]. / Biométrie oculaire à l'aide d'une fente lumineuse (Orbscan(R)).

PURPOSE: To evaluate the accuracy and reproducibility of the biometric measurements obtained with the Orbscan((R)) device in normal eyes. METHODS: Anterior chamber depth, axial length, and corneal diameter were studied in 50 normal eyes of 25 patients using the Orbscan((R)) device and A-Scan ultrasonography. For each eye, two exams were done successively and reproducibility was calculated by analyzing the difference between both measurements. RESULTS: The reproducibility of anterior chamber depth and corneal diameter measurements obtained by Orbscan((R)) was high (respectively 0.721.25% and 0.831.40%). The anterior chamber depth measurements by Orbscan((R)) and A-Scan ultrasonography were strongly correlated (rs=0.92;p<0.001). The axial length measurement obtained with the Orbscan((R)) device was less reproducible (3.554.11%). For the axial length, the Orbscan((R)) measurements and A-Scan ultrasonography measurement was poorly correlated. (rs=0.64; p<0.001). CONCLUSION: The anterior chamber depth measurement obtained with the Orbscan((R)) device showed high reproducibility and it was strongly correlated with the measurement obtained by A-Scan ultrasonography. Axial length measurement obtained with the Orbscan((R)) device was less reproducible and poorly correlated with the A-Scan ultrasonography measurement. It was not relevant for clinical application.