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Biomedical subjects

C Baudouin

Publications and source records attributed to C Baudouin.

At least 19 recordsLinked to original sources

Hyperlordosis as a possible factor in the development of spinal cord infarction.

A patient developed persistent symptoms and signs suggestive of partial spinal cord infarction after an operation involving the use of the hyperlordotic position. This position involves extension at the waist, such that both the head and feet are below the level of the waist. It is employed to increase surgical access to the abdomen. Where this position is adopted for a prolonged surgical procedure, existing risk factors for spinal cord ischaemia should urge caution in the use of epidural analgesia.

Adult↗

Changes in medical and surgical treatments of glaucoma between 1997 and 2000 in France.

PURPOSE: To analyze quantitative changes in glaucoma treatment strategies between 1997 and 2000 in France. METHODS: Numbers of ab externo trabeculectomies and other glaucoma surgeries were extracted from the national database of the French Diagnosis Related Group system, which includes data for both public and private hospitals. Mean lengths of stay and hospital costs were estimated using national cost scales published by the French Ministry of Health. Numbers of patients treated per year with latanoprost, brimonidine, or the fixed combination of dorzolamide + timolol were estimated from drug unit sales using defined daily doses for each drug. RESULTS: Between 1997 and 2000, the number of patients treated with a glaucoma drug increased from 410,000 to 734,000 patients per year. This increase was associated with the introduction of three new glaucoma drugs: 245,000 patients received latanoprost (71.0%), brimonidine (28.8%), or the fixed combination of dorzolamide + timolol (0.2%). During the same period, the surgery rate in patients receiving medical treatment declined by 47%, from 5.9% to 3.1% . The total number of glaucoma interventions declined by 4.6% (-12% in public hospitals and 0% in private hospitals). This relative stability resulted mostly from a shift from trabeculectomies to other procedures, mainly to new filtering procedures in private hospitals. CONCLUSIONS: Between 1997 and 2000, new glaucoma drugs, primarily latanoprost and brimonidine, improved intraocular pressure control and delayed surgery, reducing the glaucoma procedure rate in patients receiving glaucoma-related medical treatment by 47%.

Antihypertensive Agents↗

[Molteno implant and refractory glaucoma. Evaluation of postoperative IOP control and complications with a modified surgical procedure].

BACKGROUND: Management of refractory glaucoma is difficult because classic medical and surgical treatments are ineffective in controlling highly elevated intraocular pressure (IOP). Drainage implants are an alternative to cyclodestructive procedures in refractory glaucoma. The double-plate Molteno implant, a tube linked to two polypropylene plates, allows aqueous humor drainage from the anterior chamber towards the posterior subconjunctival spaces. The main postoperative complication is severe hypotony, potentially responsible for a decrease in visual acuity in cases of advanced glaucoma. Surgical modifications such as external tube occlusion can reduce postoperative hypotony. However, tube occlusion may lead to transient postoperative hypertony. Our retrospective study reports on double-plate Molteno implantation with intraoperative external tube occlusion associated with trabeculectomy in some cases. MATERIAL AND METHODS: Thirteen eyes of 13 patients with refractory glaucoma were included in the study (5 cases of open angle glaucoma, 7 cases of secondary glaucoma, one case of primary congenital glaucoma). All had ocular hypertony despite maximal tolerable medical treatment; 84.5% had previously undergone trabeculectomy with mitomycin (1-5 procedures) and 61% had undergone cyclophotocoagulation (1-4 sessions). All underwent double-plate Molteno implantation with external tube occlusion between 1993 and 2001. In three cases, intraoperative trabeculectomy was also performed. Visual acuity, IOP, relevant medical treatment and potential complications were reported at each follow-up visit. Complete success was defined as IOP less than 21 mmHg without treatment, while IOP control with medical treatment was considered as relative success. RESULTS: Mean (+/-SD) follow-up was 2.9+/-2.1 years (range, 9 months to 8 years). Mean (+/-SD) initial and final IOPs were 35.2+/-7 mmHg and 17.1+/-5 mmHg, respectively, i.e., a 50% IOP decrease. Mean (+/-SD) initial and final medical treatments were, respectively, 4.3+/-1.5 (61% with systemic acetazolamide) and 1.3+/-1.4 (without acetazolamide). The complete success rate was 38.5% and relative success 92.3%. Immediate postoperative hypertony occurred in 60% of the cases with external tube occlusion alone (10 cases). This hypertony was controlled with medical treatment in 2/3 of the cases but required surgical reintervention in 1/3 of the cases. For patients with intraoperative trabeculectomy (3 cases), postoperative immediate IOP without medical treatment was 2, 5 and 8 mmHg respectively. Complications reported were flat anterior chamber (1 case), visual acuity decrease (4 cases), lens opacification (1 case), macular edema (1 case), corneal edema (2 cases: 1 transient, 1 corneal decompensation) and long-term refractory hypertony (1 case). CONCLUSION: The double-plate Molteno implant is effective in controlling IOP in refractory glaucoma. External tube occlusion prevents complications related to excessive filtration; however, it may lead to transient postoperative hypertony. This hypertony can be avoided when simultaneous trabeculectomy is performed. Corneal decompensation remains the major complication of this surgical procedure.

Acetazolamide↗

[Creating a specific diagnostic and quality-of-life questionnaire for patients with ocular surface disease].

INTRODUCTION: Ocular surface diseases (OSD) affect about 15% of the population over 65 years of age. Nevertheless, OSD knowledge in the scientific community remains poor, and the healthcare system does not adequately recognize this disorder. However, many patients with OSD suffering from chronic pain experience substantial alteration in their quality of life (QoL). PURPOSE: Our work aimed at developing a patient self-evaluation questionnaire specific to OSD. This questionnaire could thus become a useful diagnostic tool that ophthalmologists could employ in daily practice in order to better understand patients'complaints and thereby correctly treat their disease. It also may serve as an evaluation tool in medical research. This article describes the phases of item generation, validation by experts, and identification of dimensions in the QoL section. METHODS: The questionnaire was developed in French by a group of experts including clinicians and methodologists. It comprised two parts: one on diagnostic aid, and the other on subjective perception of the disease (symptoms, perception of treatment, quality of life). The questionnaire was tested on five patients. It was then modified according to the patients' suggestions and tested again on 20 patients. After a second review by the scientific committee, a pilot questionnaire suitable for systematic use in quantitative studies was prepared. A cross-sectional observational study then identified the statistical dimensions of the QoL section, which led to a reduction in the total number of items. RESULTS: The resulting operational version of the questionnaire included four sections CONCLUSION: The next study will test the reproducibility of the operational version of the OSD questionnaire obtained after the item reduction phase.

Adult↗

[Apoptosis and the ocular surface].

Apoptosis, or programmed cell death, is an active phenomenon that plays a major role in most mechanisms of regulation, differentiation and wound healing. Mostly studied in the retina, apoptosis is also extensively involved in the anterior segment, especially the ocular surface. Apoptosis of keratocytes is a rapid phenomenon following excimer refractive surgery. Any epithelial aggression stimulates a series of mechanisms leading to death of deep keratocytes. The role of epithelial cell mediators may explain the superiority of LASIK compared to PRK in terms of functional rehabilitation. Conjunctiva is also a major site in which inflammation and apoptosis are combined. Proinflammatory cytokines may both amplify immune reactions and stimulate epithelial apoptosis, which is most likely to result in elimination of injured tissues. Toxic drugs also play a major role and iatrogenic apoptosis should be avoided as much as possible, especially by eliminating preservatives from eyedrops, most of which use both proinflammatory and proapoptotic agents.

Apoptosis↗

[Flow cytometry in impression cytology during keratoconjunctivitis sicca: effects of topical cyclosporin A on HLA DR expression].

PURPOSE: Immune-based inflammation has been observed as a common mechanism of keratoconjunctivitis sicca (KCS). In KCS-affected eyes, up-regulated expression of HLA DR by conjunctival epithelial cells has been demonstrated in impression cytology (IC) specimens using a technique of flow cytometry. The purpose of this study was to monitor the effects of topical cyclosporin A on the expression of this marker over a 12-month period of treatment. METHODS: Patients with moderate-to-severe KCS included in a large European multicenter clinical trial (Cyclosporin Dry Eye Study, Allergan, Irvine, CA) underwent collection of IC specimens at baseline, month 3, month 6, and month 12. They randomly received 0.05% or 0.1% cyclosporin A or vehicle. Patients randomized to receive vehicle received 0.1% cyclosporin A from month 6 onwards. Specimens were processed and analyzed in a masked manner by flow cytometry, using monoclonal antibodies directed to HLA DR. RESULTS: We included 169 patients in this study. HLA DR expression, both in percentage of positive cells and level of expression, was highly significantly reduced after 0.05% and 0.1% cyclosporin A treatment at months 3, 6, and 12 compared with baseline values, whereas vehicle did not induce any change in HLA DR expression over time. The 0.05% and 0.1% cyclosporin emulsions were significantly more effective than the vehicle in reducing HLA DR at months 3 and 6 (0.05%) and at month 6 (0.1%). CONCLUSIONS: Topical cyclosporin A strikingly reduced HLA DR, whereas the vehicle, used as a control tear substitute, had almost no effect. This study confirms that cyclosporin A may be effective in reducing conjunctival inflammation in moderate-to-severe KCS and is consistent with clinical results in this indication.

Administration, Topical↗

[Acute bilateral anterior uveitis with hypopyon revealing creeping angle-closure glaucoma].

We report the case of a 35-year-old Asian woman presenting with bilateral anterior uveitis with hypopyon associated with high intraocular pressure. In her past history, she described intermittent angle-closure episodes. Anterior chamber examination and ultrasound biomicroscopy revealed a creeping angle-closure glaucoma. This clinical entity can affect Asians. The angle is gradually shortened with an iris bombé that brings the peripheral iris close to the external angle wall. The acute episodes are often poorly symptomatic. An early diagnosis may prevent glaucoma damages.

Adult↗

[Effect of preservatives on the conjunctiva: a comparative study of beta-blocker eye drops with and without preservatives in glaucoma patients].

PURPOSE: To compare the effect of timolol with or without preservatives on the conjunctival epithelium of glaucoma patients. METHODS: A retrospective study using impression cytology (IC) was conducted on patients treated with 0.5% timolol with or without 0.01% benzalkonium chloride (BAC). Fifteen eyes from 15 patients treated with timolol, BAC+ and 17 eyes from 17 patients treated with timolol, BAC- were included in two groups comparable for age and duration of treatment lasting at least 1 year. Specimens were analyzed by flow cytometry for inflammatory profile (using antibodies directed against HLA DR and ICAM-1) and mucin detection (anti-M1/MUC5AC antibody). RESULTS: IC analyses showed a significant increase in the expression of the two inflammatory markers, HLA DR and ICAM-1 in the timolol, BAC+ group and also a significant decrease in goblet cell density in the same group as compared to the timolol, BAC- group. CONCLUSION: The use of long-term preserved beta-blocker in glaucoma patients is associated with a direct subclinical epithelial toxicity in the conjunctiva, as already demonstrated by previous experimental studies.

Adolescent↗

Environmental pollutants and skin cancer.

We are increasingly exposed to environmental pollution. Pollutants can be inhaled, ingested or come into contact with the skin depending on the form in which they occur. On metabolization, activation, or accumulation, pollutants can become extremely toxic for the vital organs and this is often related to a strong genotoxic effect. Since the skin acts as a barrier between the organism and the environment, it is frequently directly exposed to pollution. It is very often degraded by polluting agents and acts as an inlet toward other tissues. Numerous studies in man recognize and demonstrate the carcinogenic power of certain pollutants in the digestive and respiratory tracts. The "pollutants" that react most specifically with the skin are: ultraviolet radiation, polycyclic aromatic hydrocarbons (e.g., benzo[a]pyrene), volatile organic compounds (e.g., benzene), heavy metals, and ozone. Ultraviolet radiation, a "physical" pollutant, has been described as being the factor responsible for most skin cancers in man. The genotoxicity of UV light is well documented (type of lesion or mutation, etc.) and its carcinogenic effect is clearly demonstrated in vivo in man. A few epidemiological studies describe the carcinogenicity of certain pollutants such as arsenic or lead on the skin. However, most of the evidence for the role of pollutants in skin cancers comes from in vivo animal studies or from in vitro studies (e.g., PAHs). In this report, different studies are presented to illustrate the research strategies developed to investigate the mechanism of action of "chemical" pollutants and their potential role in human skin pathology. All the study models and the associated techniques of investigation are tools for a better understanding and thus more efficient prevention of the deleterious effects caused by the environment.

Animals↗

Prevalence of ocular symptoms and signs with preserved and preservative free glaucoma medication.

AIM: To determine the incidence of ocular toxicity of preservatives with glaucoma medications. METHODS: A prospective epidemiological survey was carried out in 1999 by 249 ophthalmologists on 4107 patients. Ocular symptoms, conjunctiva, cornea, and eyelids were assessed. A chi(2) test was used for differences between preserved eye drops (P) and preservative free eye drops (PF). RESULTS: 84% patients used P, 13% received PF, and 3% a combination of P and PF eye drops. All symptoms were more prevalent with P than with PF drops (p<0.001): discomfort upon instillation (43% versus 17%), and symptoms between instillations such as burning-stinging (40% versus 22%), foreign body sensation (31% versus 14%), dry eye sensation (23% versus 14%), tearing (21% versus 14%), and eyelid itching (18% versus 10%). An increased incidence (>2 times) of ocular signs was seen with P eye drops. The prevalence of signs and symptoms was dose dependent, increasing with the number of P drops. A reduction in the symptoms and signs was observed when patients changed from P to PF eye drops (p<0.001). CONCLUSIONS: Symptoms and signs are less prevalent when PF drops are used. Moreover, most of the adverse reactions induced by P glaucoma medication are reversible after removing preservatives.

Adolescent↗

Confocal microscopic examination of trabecular meshwork removed during ab externo trabeculectomy.

AIMS: The aim of the ab externo trabeculectomy (AET) is to remove the external portion of the trabecular meshwork (ETM) responsible for the main aqueous outflow resistance in glaucoma patients, with no opening of the anterior chamber. ETM characteristics were evaluated with a confocal microscope. METHODS: A prospective comparative observational case series was performed in 60 consecutive medically treated patients with primary open angle glaucoma and eight postmortem normal donors' eyes that underwent AET. Once deroofing the Schlemm' s canal (SC), a deeper dissection led to removal of a coherent membrane (ETM) which allowed satisfactory aqueous egress through the remaining intact internal trabecular meshwork (TM) layers. After fixation with acetone and immunostaining with anti-vimentin antibody, ETM were analysed with a confocal microscope. RESULTS: Glaucomatous ETM (mean thickness: 29.5 (7.6) micro m) were characterised by a severe paucicellularity compared with the controls (respectively 37.3 (9.7) cells/area and 167.5 (24.9) cells/area, p<10(-4)). ETM analysis showed involvement of both cribriform and corneoscleral layers. ETM cell density was significantly decreased in case of preoperative fluorometholone instillation. CONCLUSION: Paucicellularity of glaucomatous TM is confirmed by this original technique. Structural characteristics of the ETM, whose removal allows satisfactory aqueous egress, suggest that aqueous outflow resistance not only involves inner wall of SC and juxtacanalicular meshwork but also corneoscleral trabecular layers.

Adult↗

[Clinical evaluation of the ocular safety of Amukine 0.06% solution for local application versus povidone iodine (Bétadine) 5% solution for ocular irrigation) in preoperative antisepsis].

INTRODUCTION: The aim of this monocentric, randomized, comparative, open study was to evaluate the safety of Amukine 0.06% solution (an isotonic hypochloride sodium solution) versus a 5% povidone iodine solution (Bétadine 5% solution for ocular irrigation) in antisepsis before cataract surgery. MATERIAL AND METHODS: One hundred and thirteen patients, aged between 49 and 90 years, were included and split, after randomization, into two groups: one testing Amukine 0.06%, the other testing a 5% povidone iodine solution. For each group, after local anesthesia, the antiseptic procedure consisted of an antisepsis of periocular teguments followed by an eye antisepsis through the instillation of two drops of the tested product in the conjunctival fornices. The safety evaluation was performed by grading superficial punctate keratitis 24 hours after surgery (slit lamp examination after fluorescein instillation). Conjunctival hyperemia scores by examination of the bulbar conjunctiva before the first instillation, immediately before surgery, and 24 hours after surgery were also compared. RESULTS: One hundred and seven reports were analyzed. Concerning the presence of corneal superficial punctate keratitis 24 hours after surgery, mean scores were not different (0.27 for the Amukine 0.06% group and 0.38 for the povidone iodine group; p=0.27 Mann Whitney test). The observations did not show a different progression of conjunctival hyperemia depending on the treatment group (p=0.65 (immediately after application) and p=0.52 (after 24 hours); Mann Whitney test). CONCLUSION: In this study, the ocular safety of Amukine 0.06% solution was not different from a 5% povidone iodine solution. Therefore, Amukine 0.06% is a new interesting approach to surgical antisepsis in ophthalmology and an alternative in case of iodine allergy.

Aged↗

[Corneal stromal changes after LASIK].

PURPOSE: To assess stromal modifications after laser in situ keratomileusis (LASIK) for myopia using in vivo confocal microscopy. METHODS: Thirteen eyes from 10 patients were examined before surgery and at days 8 and 30 after surgery using an in vivo confocal microscope coupled with a Z-Scan system. Stromal morphological changes, keratocyte density, flap thickness, and subclinical haze were evaluated and compared at different time points. RESULTS: Microfolds at the Bowman's layer were found in 55%, eyes as well as variable reflectivity particles located at the interface level in all postoperative examined eyes. The mean flap and activated-cell area thicknesses were respectively, 101+/-28 micrometer and 50.5+/-14 micrometer with a significant negative correlation (r=-0.89, p=0.01). The intensity of the added peak (47.3+/-8.6% scattered light), corresponding to the subclinical haze, as measured by Z-Scan, was also negatively correlated with the flap thickness (r=-0.89, p=0.01). CONCLUSION: This study confirms the presence of microfolds and particles at the interface level as subclinical complications. Evaluating the keratocytic activation by confocal microscopy can lead to a better understanding of corneal wound healing after LASIK and can help to improve the techniques. The flap thickness seems to be involved in the cellular activation induced by LASIK.

Adult↗

[Influence of corneal refractive surgery on the lacrymal film].

Functional and clinical signs of ocular surface involvement are observed after corneal refractive surgery (LASIK or PRK) and are evocative of dry eye syndrome. The surgical process induces a total or partial section or abrasion of the corneal-sensitive nerves. This anatomical consequence of surgery is responsible for a lachrymal dysregulation with reduced tear production. Neither technique is currently able to demonstrate its superiority in preserving the lachrymal secretion. These postoperative findings should be clearly explained to patients before surgery and discomfort should be prevented with artificial tears and/or punctual plugs for 1 to 6 months after surgery.

Dry Eye Syndromes↗

[Use of brimonidine 0.2% in treatment of glaucoma or ocular hypertony after poorly tolerated beta-blocker treatment].

This study intended to evaluate the advantages of brimonidine tartrate 0.2% (Alphagan((R))), a selective alpha-2 receptor agonist, relaying a poorly tolerated beta-blocker treatment. Effectiveness, as assessed by intraocular pressure, local and general tolerance of the treatment, and the quality of life of the patients included in the study, was compared for these two eye drops. This multicenter and prospective study, performed by 450 ophthalmologists, included 807 adults presenting with glaucoma or ocular hypertony over 8 months. After a poorly tolerated beta-blocker treatment, which had started at least 6 months before, these patients received brimonidine over 8 weeks. At 3 successive visits, intraocular pressure, biomicroscopic examination results, and visual acuity were recorded. A quality-of-life questionnaire evaluating breathlessness, fatigue, depressive mood, loss of appetite, and satisfaction with the treatment was also given to patients. In the 731 patients observed in the study, the analysis concluded a statistically significant decrease in intraocular pressure (-2.5mmHg) and in the cardiovascular parameters during brimonidine treatment: blood pressure was reduced by 3mmHg and 1.1mmHg for systolic and diastolic pressure, respectively. The heart rate rose by 1.7 beats/min. The quality-of-life questionnaire revealed less breathlessness (-26%), fatigue (-24.9%), depressive mood (-19.3%), and better appetite (+8.2%). The feeling of satisfaction with the brimonidine treatment was significantly improved for 95 patients. However, 12% of all patients stopped their treatment because of adverse effects. Brimonidine improved the glaucomatous patients' quality of life, at least in some areas. Improved intraocular pressure could at least in part result from better compliance with the treatment. Brimonidine is an encouraging alternative after an unsatisfactory beta-blocker treatment.

Adrenergic alpha-Agonists↗

[The phenol red thread first results for the assessment of the cut-off value in ocular sicca syndrome].

PURPOSE: To determine the cut-off value of the phenol red-impregnated thread test (Zone-Quick((R)), Menicon trade mark ) for the diagnosis of ocular sicca syndrome using the ROC (receiver operating characteristic) procedure and to estimate the agreement with the Schirmer I test (without anesthetics). MATERIAL: and methods: Fifty-four consecutive patients (including 50 females) with dry eyes, presumably related to an immune disorder, were recruited on the basis of subjective ocular symptoms and medical history (sicca syndrome). Both the phenol red thread (PRT) test and the Schirmer I test (testing periods, 15s and 5min, respectively) were performed in both eyes in random order. Only the lowest result for each test was used in statistical analyses. The same procedure was applied to 29 normal volunteers (no subjective symptoms). The patient and the control groups were matched for age and gender (mean age, 58.1 and 59.6, respectively). RESULTS: The ROC procedure showed that a cut-off value of 12mm in the PRT test provided the best ratio between sensitivity and specificity (56% and 69%, respectively) for the detection of dry eyes. Using this threshold, the agreement with the Schirmer I test was highly significant (kappa test; P<10(-3)). However, discordant results were observed in 32% of subjects. CONCLUSION: Giving a cut-off value at 12mm, the sensitivity and specificity of the PRT are 56% and 69%, respectively. Even if the agreement with the Schirmer I test is highly significant, 32% of patients have discordant results. These two methods of functional assessment of tear secretion are therefore complementary and further studies remain necessary to better understand the place of both tests in clinical practice.

Coloring Agents↗