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Biomedical subjects

L Laroche

Publications and source records attributed to L Laroche.

At least 19 recordsLinked to original sources

Effects of topical anaesthetics and fluorescein on the real-time PCR used for the diagnosis of Herpesviruses and Acanthamoeba keratitis.

BACKGROUND: The early microbiological diagnosis of corneal infections may prevent the condition from worsening. AIM: To study the potential interferences of oxybuprocain and fluorescein solutions used by ophthalmologists on the performances of the real-time polymerase chain reaction (PCR) carried out as routine test for diagnosis of keratitis. METHODS: Quantified suspensions of Herpes simplex virus (HSV1), Varicella zoster virus (VZV), Cytomegalovirus (CMV) and Acanthamoeba with and without oxybuprocain or fluorescein added before DNA extraction were tested by real-time PCR. RESULTS: The capacities of the real-time PCR to detect HSV, VZV, CMV and Acanthamoeba were reduced by oxybuprocain and fluorescein. Both products diluted to 1/16 reduced the PCR detection capacities for more than 2 logs (DNA copies/sample). CONCLUSIONS: The simultaneous introduction of fluorescein or topical anaesthetics into the tubes containing the specimens to be tested by PCR may lead to false negative results. Because corneal specimens for microbiological diagnosis of keratitis are obtained after topical administration of anaesthetics and corneal staining with fluorescein, ophthalmologists should be aware to rinse the eye surface intensively with appropriate eye solutions to minimise the risks of misdiagnosis.

Acanthamoeba↗

[Heavy silicone oil as internal tamponade for retinal detachment: efficacy and tolerance].

INTRODUCTION: To evaluate the tolerance and efficacy of heavy silicone oil as internal tamponade for retinal detachment surgery. PATIENTS AND METHODS: Sixty-six eyes requiring heavy silicone oil for retinal detachment, with at least 1 month follow-up, were retrospectively studied. Preoperative status, surgical technique, tolerance, and anatomical and functional results were analyzed from the patient's file. Indications for heavy silicone injection were inferior retinotomy or inferior retraction in 65% of cases. PVR grade C was present in at least 63% of cases. Retinotomy was performed in 45% of cases. An exchange procedure was performed versus DKline in 65% of cases. Mean follow-up was 7 +/- 4 months. RESULTS: At the end of follow-up, 59% of eyes had a completely reattached retina, 32% without internal tamponade. Another surgery was necessary in 54% of cases. During follow-up, mean intraocular pressure was normal, and there was a significant intraocular inflammation in three cases (4.5%). In seven cases of the 44 ablations of heavy silicone oil, an adherence of residual bubbles was present. Redetachment occurred after ablation for anatomical success in 41% of cases. BCVA was better than 0.05 (20/400) in 54% of cases at the end of follow-up. CONCLUSION: Heavy silicone was well tolerated and seems not to be pro-inflammatory in our study. It is a good alternative to standard silicone for inferior retinotomy and inferior breaks without PVR. It is not a treatment of inferior retraction, and is not a long-term internal tamponade. During the ablation of heavy silicone oil, adherence of residual bubbles is possible, in which case a coaxial light or an endoillumination could be needed during ablation.

Adolescent↗

[Advantages of the autorefractometer and the Orbscan for measuring pupil diameter].

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.

Adolescent↗

[Prevention of proliferative vitreoretinopathy using 5-FU heparin: clinical tolerance and efficacy].

PURPOSE: To study the safety and efficacy of adjuvant combination therapy using 5-fluorouracil and heparin for prevention of proliferative vitreoretinopathy (PVR) during vitrectomy for retinal detachment surgery. METHODS: Two consecutive groups of 30 eyes with a rhegmatogenous retinal detachment (grade C1 or more) were prospectively compared. In the study group, 5-FU and heparin were administrated in the intraoperative infusion. Clinical safety and the efficacy were regularly studied over 1 year. RESULTS: In the 5-FU heparin therapy group, keratitis was more frequently observed the 1st day after surgery (p = 0.005), but not after 1 week (p = 0.54). However, conjunctival hyperemia was more severe after 1 and 7 days (p = 0.04). In both groups, no differences were found concerning intraocular pressure, postoperative hemorrhage or inflammatory reaction (flare) of the anterior chamber and the aspect of the eyelids (p > or = 0.14). The number of reoperations resulting from PVR, after 1 month and 1 year, was not significantly different between the two groups (p > or = 0.3). The reattachment rate and visual acuity (BSCVA) were not statistically different after 1 year (p > or = 0.12). CONCLUSION: Adjuvant combination therapy using 5-FU and heparin seems to be safe. However, its efficacy needs to be demonstrated by larger studies including eyes presenting a lower grade of PVR (grade B).

Drug Therapy, Combination↗

[Ocular biometry using 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.

Biometry↗

[Crystalline lens biometry using A-scan ultrasound and the Orbscan device].

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.

Adolescent↗

Peripheral gangrene in adult-onset Kawasaki disease.

Kawasaki disease (KD) is an acute vasculitis characterized by marked tropism of the coronary vessels. Usually a childhood disease, KD can occasionally be observed in adults. We report a case of adult-onset KD that presented as a prolonged fever of unknown origin with subsequent development of severe vasculitis, manifested by coronary aneurysms and peripheral gangrene of the lower limbs. Therapy with intravenous immunoglobulins, corticosteroids, aspirin, anticoagulants, and prostacyclin analogue resulted in rapid improvement in the patient's condition but he required partial distal amputation for irreversible gangrene. Peripheral ischaemia leading to gangrene is a very rare feature of KD vasculitis with only 19 cases previously published in the Medline-indexed literature. The outcomes of those patients were poor, being either fatal or requiring distal amputation. All prior cases affected young children less than 1 year old and, to the best of our knowledge, the present case is the first description of peripheral gangrene in adult-onset KD.

Adult↗

[Acute retinal necrosis: clinical presentation, treatment, and prognosis in a series of 22 patients].

PURPOSE: To evaluate the clinical outcome and medical management in a series of patients diagnosed with acute retinal necrosis. MATERIAL AND METHODS: Between 1993 and 2000, 22 patients suffering from acute retinal necrosis were referred to our department. We retrospectively reviewed the clinical course, delay between diagnosis and first clinical manifestation, biological profiles, treatment and complications. RESULTS: All patients had vitreous inflammation; retinitis was seen upon examination in 82% of the cases. Nevertheless, for six patients (27% of the cases), failure to recognize the diagnosis led to delay (mean, 5.5 days) between the first ophthalmological examination and antiviral therapy. Nineteen patients underwent laboratory evaluation, and virological diagnosis was made in 16 of them: varicella zoster virus was found in 11 cases, herpes simplex type 1 in three cases, and herpes simplex type 2 and cytomegalovirus in one case each. Nine patients were treated with a combination of aciclovir and foscarnet and 13 with aciclovir alone. Among the 16 patients who received aciclovir, one did not respond to therapy after 2 days and was cured only after foscarnet was added. Recurrence occurred at the end of treatment in only one patient. Retinal detachment complicated the course for 11 patients and was always associated with proliferative vitreoretinopathy. Among those, seven of the ten patients who accepted surgery were successfully treated. Eleven out of 22 patients had a final visual acuity up to 20/200 and two up to 20/40. CONCLUSION: In our series, acyclovir alone was sufficient to cure the majority of cases. Even with antiviral therapy, the prognosis of acute retinal necrosis remains poor. Retinal detachment is the main complication.

Acyclovir↗

[Biometric study of acute-angle-closure glaucoma using Orbscan and echography].

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.

Acute Disease↗

[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↗

[Anterior segment of the eye and diabetes mellitus].

OBJECTIVE: To study the damage to the anterior segment of the eye during mellitus diabetes. METHODS: We prospectively studied the anterior segment of the eye in 200 diabetic patients and 200 patients with no history of diabetes (control group). Parameters included the corneal curvature radius, corneal thickness, central corneal sensitivity (Cochet Bonnet esthesiometer), pupil diameter before and after dilation using tropicamide and phenylephrine eye drops, delay for maximal pupil dilation, lens transparency, and intraocular pressure. The damage to the anterior segment was compared in both groups and was correlated with the parameters of diabetes (type, duration, and equilibration), retinopathy grade, and peripheral neuropathy. RESULTS: Corneal geometry (i.e., curvature radius and thickness) and intraocular pressure did not correlate with diabetes. Cataract was significantly influenced by diabetes (p<0.001). The duration needed to obtain pharmacological maximal mydriasis significantly correlated with iris color (rs=0.47, p<0.001), patient age (rs=0.28, p<0.001) and diabetes (rs=0.25, p<0.001). Dilation was significantly longer in the diabetic patient than in those of the control group (36.5 min vs 30.7 min, p<0.001). Corneal sensitivity significantly correlated with age (rs=0.48, p<0.001) and diabetes (rs=0.53, p<0.001). Corneal sensitivity was decreased in the diabetic group (5.42 vs 5.94, p<0.001) and it correlated with retinopathy grade (rs=0.47, p<0.001) and with peripheral neuropathy (rs=0.15, p<0.001). Sensitivity and specificity of hypoesthesia in detecting peripheral neuropathy were 67.4% and 49.4%, respectively. Among the parameters of diabetes, duration of progression showed the strongest correlation with damage to anterior segment (rs > or = 0.25, p<0.001). CONCLUSION: Diabetes influences lens transparency, pharmacological pupil dilatation and corneal sensitivity. In spite of the unspecific character of the damage and the subjectivity of the measurement, corneal sensitivity is an interesting parameter to take into consideration among diabetic patients.

Anterior Eye Segment↗

[Pharmacological adjuvants for surgical treatment of proliferative vitreoretinopathy].

Proliferative vitreoretinopathy (PVR) is the major cause of retinal detachment surgery failure. Many adjuvants were studied in vitro and on animals, some were studied on humans. Daunomycin seems to reduce PVR recidivism. 5-FU and steroids are nontoxic but their efficacy is not clear. Heparin reduced postoperative inflammation and seems to reduce PVR recidivism when associated with 5-FU. Associating heparin and steroids seems to reduce PVR in some groups of patients (aphakic, anterior PVR). Colchicine and retinoic acid per os are ineffective, silicone oil is effective as an internal tamponade but not as an adjuvant of PVR. Currently, no molecule has proven efficacy as an adjunctive treatment of PVR.

Chemotherapy, Adjuvant↗