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Biomedical subjects

J L Arné

Publications and source records attributed to J L Arné.

At least 19 recordsLinked to original sources

[A murine model of transitory optic neuropathy based on small interference RNA-induced OPA1 silencing in vivo (gene mutation associated with Kjer's disease)].

PURPOSE: Developing a murine model of OPA1 linked optic neuropathy. METHODS: Intravitreal injections (in adult C57BL/6J mice) of small interference RNA (siRNA) specific to OPA1 were performed in the left eye. The right eye served as control, injected with nonspecific siRNA (siRNA scramble). Visual evoked potentials and flash electroretinograms were performed 5 and 12 days after injection. Three months after injection, microscopy of optic nerve sections was performed. RESULTS: The electrophysiological tests showed a significant reduction in the VEP when the siRNA OPA1-injected eye was stimulated, compared with the control eye injected with siRNA scramble. The electroretinogram was normal in both eyes: no significant difference between the right and the left eye was found. Three months after injection, no measurable axonal degeneration was found in either eye. CONCLUSION: The reduced expression of OPA1 based on RNA silencing in adult mice could induce reversible dysfunction of retinal ganglion cells.

Animals↗

[Automobile driving and visual aptitude in 100 patients over 60 years of age].

OBJECTIVE: To evaluate visual capacity and automobile driving in a sample of individuals over 60 years of age based on the visual function criteria as defined in the 29 May 1997 French Journal Officiel. MATERIAL AND METHODS: Drivers over 60 years of age were included in a prospective monocentric epidemiological study between January and March 2005. Binocular visual acuity and monocular visual acuity were measured in subjects with their optical corrections. Binocular or monocular visual field was tested depending on visual acuity results. Etiologies of visual acuity loss and visual field impairment of each eye were recorded in patients who did not meet the required criteria. RESULTS: One hundred patients were included (mean age, 70.7 years +/- 7.12 years). Twenty-nine patients did not meet the required criteria (29%; 95% confidence interval=[20.1;37.9]). On these 29 patients, 20 (69%; 95% CI=[52.2;85.8]) were unfit for driving an automobile with potential reversibility, whereas nine (31%; 95% CI=[14.2;47.8]) were permanently unfit from a visual point of view. CONCLUSION: The frequency with which patients ignore their poor distance visual acuity and the possibility of reversing the problem make it clear that the ophthalmologist has a role to play in detecting and informing patients.

Age Factors↗

[Deep anterior lamellar keratoplasty in the surgical treatment of keratoconus. A 1-year follow-up].

OBJECTIVE: To evaluate the results of deep anterior lamellar keratoplasty (DALK) using dissection with air or with a viscoelastic substance in the surgical treatment of keratoconus as an alternative to penetrating keratoplasty. MATERIAL AND METHODS: This prospective monocentric noncomparative study involved patients with contact lens-intolerant keratoconus operated on between February 2001 and September 2002. Deep lamellar dissection was performed either by air injection into the cornea to create a white emphysema of the stroma or by viscoelastic injection. This allows the surgeon to separate Descemet's membrane from the posterior stroma using the air-to-endothelium interface. Previously, aqueous humor was replaced by air in the anterior chamber to visualize the posterior corneal surface. A full-thickness allogenic corneal button was sutured into the recipient bed, after stripping its Descemet's membrane. RESULTS: Fifteen eyes of 15 patients (mean age, 41.2 years) underwent DALK. The mean preoperative visual acuity was 0.11+/-0.06. At 1 year, the mean best corrected visual acuity was 0.47+/-0.16 (p<0.001). Mean keratometric astigmatism was reduced from 6.97+/-3.3 D to 2.77+/-1.76 D at 1 year (p<0.001). Specular microscopy 3 months postoperatively revealed average endothelial cell counts of 2018+/-662/mm2, while 1 month preoperatively this value was 2604+/-235/mm2 (cell loss, 22.5%; p>0.05). Perforation of Descemet's membrane during surgery occurred in five eyes (33.3%). Two cases were converted to penetrating keratoplasty. There was no endothelial rejection. CONCLUSION: In this series, DALK appears to be a promising procedure for treatment of keratoconus with encouraging refractive outcome, no progressive primary graft failure, and no allogenic endothelial graft rejection. DALK is an interesting alternative for penetrating keratoplasty even if it is technically more difficult.

Adolescent↗

[Corneal transplantation of a corneal graft with radial keratotomy].

INTRODUCTION: We report the case of a patient operated on for penetrating keratoplasty with a corneal graft with radial keratotomy. CASE REPORT: A 27-year-old man underwent penetrating keratoplasty for keratoconus. Graft incisions of radial keratotomy were discovered the day after surgery. Corneal graft examination and endothelial cell density were carried out postoperatively. CONCLUSION: This case shows the potential problem of corneal graft assessment before transplantation. An examination of the donor's cornea before its removal with a portable slit lamp could make graft quality evaluation safer.

Adult↗

Pain relief with intracameral mepivacaine during phacoemulsification.

AIM: To assess the efficacy and safety of an intraoperative intracameral injection of mepivacaine, administered when patients experienced pain during the course of cataract surgery under topical anaesthesia. METHODS: This is a prospective placebo controlled double masked randomised clinical trial. 50 eyes were included; 25 receiving the active compound and 25 receiving placebo. Mepivacaine (2%, 0.4 ml) or placebo was administered intraoperatively under the iris of the patients who experienced pain during the course of phacoemulsification in spite of previous topical anaesthesia. Efficacy was evaluated by the patients themselves using a five point subjective pain rating scale, the Keele verbal pain chart. Safety was measured by assessing intraocular inflammation (clinical evaluation and laser flare meter), intraocular pressure, and endothelial cell count. RESULTS: The pain rating score significantly diminished after intracameral injection in the mepivacaine group (mean 3.0 (95% CI 2.6-3.4) v 0.8 (0.3-1.3), p<10(-4))) while remaining unchanged in the placebo group (2.9 (2.6-3.2) v 2.9 (2.5-3. 3)), the mean reduction in pain score being significantly different between the two groups (p<10(-4)). There was no indication of increased postoperative ocular inflammation, intraocular pressure change, or endothelial cell loss. CONCLUSIONS: These results suggest that it may not be necessary to systematically add intracameral anaesthesia with topical anaesthesia for cataract surgery. An intraoperative intracameral injection, performed only in patients who happen to suffer during surgery, is safe and effective.

Aged↗

Visual outcome after paediatric cataract surgery: is age a major factor?

AIMS: To determine functional results after unilateral and bilateral cataract surgery in children with different aphakic optical correction. METHODS: In this retrospective study, we evaluated visual acuity and binocular vision in 107 children who underwent cataract surgery during the 10 year period from 1985 to 1995. Aphakia was corrected by an intracapsular intraocular lens (IOL), spectacles or contact lenses. RESULTS: Mean visual acuity was > 20/40 (< 0.3 log MAR) with normal binocular vision in 58 children over 7 months of age operated on for bilateral cataracts. Pseudophakic eyes regained visual acuity > 20/63 (< 0.5 log MAR) more often (90%) than aphakic eyes (46%) (p < 0.001). Binocular vision was also achieved more often after IOL implantation (p < 0.001). Visual outcome of early bilateral cataracts was less satisfactory in children with abnormal foveolar function. For 49 children who had surgery for unilateral cataracts, prognosis was poor when surgery was performed before the age of 7 months. For cataract surgery in older children (> or = 7 months) mean visual acuities were better with IOL implantation (p < 0.05). CONCLUSION: Cataract surgery with unilateral and bilateral IOL implantation can provide a beneficial effect on final visual outcome in children who are operated on before abnormal foveolar function develops.

Adolescent↗

Annexin V-coated intraocular lenses.

PURPOSE: To assess whether annexin V-coated poly(methyl methacrylate) (PMMA) intraocular lenses (IOLs) prevent postoperative inflammation in rabbit eyes. SETTING: Department of Ophthalmology, Hôpital Purpan, Toulouse, France. METHODS: Thirteen IOLs coated with annexin V were implanted in 13 rabbit eyes; the contralateral eyes received uncoated IOLs. Postoperative fibrin was quantitated by daily slitlamp examination until the anterior chamber was completely clear. Results were analyzed using a Wilcoxon test. Ocular toxicity was evaluated by light and electron microscopy. RESULTS: Eyes with the annexin V-coated IOLs had less severe inflammation on the first postoperative day, and the inflammation resolved more quickly than in eyes with uncoated IOLs (P < .05). No annexin V was released postoperatively, nor were there signs of ocular toxicity. CONCLUSION: Annexin V-coated lenses effectively reduced postoperative inflammation in rabbit eyes.

Animals↗

Role of interleukin 6 in the inflammatory response after cataract surgery. An experimental and clinical study.

The mechanism of uveitis following cataract surgery, which is mediated in part by the cyclooxygenase pathway, is complex, the complexity of which is likely to be due to several factors. We investigated the possible local involvement of interleukin 6 (IL-6) in this response. Using a specific bioassay, we showed a dramatic increase of IL-6 levels (> 4 x 10(3) times) in all of the aqueous humors of 12 patients following cataract surgery. The IL-6 levels in serum samples were below detection limits, indicating a local production of this cytokine. In addition, the injection of highly purified recombinant interleukin 6 in the anterior chamber of the eye in rabbits resulted in an inflammatory response. These observations suggest that IL-6 may play a crucial role in the occurrence of inflammation after cataract surgery, and it may lead to new therapeutic approaches to this problem.

Animals↗

Localization of acidic fibroblast growth factor in proliferative vitreoretinopathy membranes.

The pathogenesis of proliferative vitreoretinopathy (PVR) membranes remains poorly understood. We have studied the presence of acidic fibroblast growth factor (aFGF), a potent mitogen for many cells, within these membranes. We have used affinity purified monospecific anti-aFGF polyclonal antibodies, in conjunction with highly sensitive immunofluorescence techniques. The labelling was exclusively localized to cell bodies and was absent from the extracellular matrix. Double labelling techniques revealed that all cytokeratin positive cells (probably pigmented epithelial cells) and macrophages contained aFGF-like immunoreactivity, whilst glial cells were unlabelled. Appropriate controls indicated the specificity of the antibodies. Hence, the presence of this mitogenic molecule within certain cell types constituting PVR membranes may contribute to the pathogenesis.

Animals↗

[Culture of retinal capillary endothelial cells].

The culture of retinal capillary endothelial cells involves certain problems concerning contamination by pericytes, the maintenance of differentiation and the duration of culture viability. A procedure for the isolation and culture of capillary endothelial cells from bovine retina which overcomes these difficulties, is described. Microvessel fragments isolated by mechanical dispersion and filtration techniques adhere strongly to dishes coated with extracellular matrix produced by bovine corneal endothelial cells. The first migrating cells emerge from the original microvessel fragments two days after plating. This technique and subsequent cloning provides migrating and proliferating cells derived only from the retinal capillaries and uncontaminated by other cell types such as pericytes. Endothelial cells were grown on gelatin coated dishes in a serum supplemented medium (10% calf serum). Cell proliferation was significantly enhanced by the addition of basic fibroblast growth factor (1 ng/ml) to the culture medium. In these culture conditions, retinal capillary endothelial cells can be repeatedly passing without the loss of their principal morphological characteristics and some of the differentiated properties of endothelial cells. Primary cultures and subcultures, at least up to the 8th passage, formed a monolayer of small, elongated, tightly-packed, contact inhibited cells which expressed Factor VIII-related antigen. Ultrastructural examination by transmission electron microscopy of confluent bovine retinal capillary endothelial cells showed many tight junctions and Webel Palade granules. These studies provide new means for the isolation and culture of retinal capillary endothelial cells and presents evidence for growth factor requirements for the ability of cells to be repeatedly passing.

Animals↗

[Value of adjustable sutures in the treatment of diplopia].

Adjustable sutures have been used as a curative procedure in 31 cases of diplopia, 16 cases of plegic causes, 4 cases of acute concomitant squint and 11 cases of mechanical strabismus: thyroid myopathy, orbital fracture, oculomotor imbalance after scleral indentation. In oculomotor paralysis if a few functional motor units remained at plegic muscle level, we were able to obtain new rotational balance by combining, with adjustable sutures, recession and resection of the couple agonist-antagonist. On the other hand, if no functional motor unit remained, it was then necessary to turn to the muscular translocation process modulated by adjustable surgery. In acute concomitant strabismus, adjustable retroposition of the medial rectus enabled us to fall back into an area controlled by fusional vergencies. Lastly, in mechanical strabismus by passive limitation, adjustable sutures usually enabled hyperaction of the contralateral synergists to be controlled and to bind a new rotational balance, compatible with a simple binocular field of vision. The advantage of this technique was to adapt, on adjustment, the motor response to the new innervational background which had disappeared under anaesthesia.

Adolescent↗