Biomedical subjects

M Boissonnot

Publications and source records attributed to M Boissonnot.

At least 19 recordsLinked to original sources

PubMed2005

[Ultrastructural study of epiretinal membrane stained by trypan blue: 15 case reports].

INTRODUCTION: Idiopathic epiretinal membrane results from detachment of the posterior hyaloid and is believed to be related to naturally occurring defects in the internal limiting membrane (ILM) of the retina. Vitrectomy and peeling are the treatment of choice. Trypan blue 0.15% (TB) stains epiretinal membrane and internal limiting membrane. It allows selective and complete removal, facilitating surgery, with less retinal damage. An ultrastructural study was conducted showing ultrastructural features of idiopathic epiretinal membranes (ERM) and those of the internal limiting membrane and its connections with the retinal side. MATERIAL AND METHODS: After pars plana vitrectomy and induction of posterior vitreous detachment, 0.2 ml TB 0.15% was injected over the ERM in an air-filled eye. The stained tissue was peeled with intraocular forceps. Specimens were at once collected in 4% glutaraldehyde for a transmission electron microscopy study. RESULTS: TB may allow complete and easier ERM and ILM peeling. The staining does not present toxic effects. The major cellular contingent is represented by glial cells, participating actively in neocollagen synthesis. Their presence supports the hypothesis of a migratory movement of retinal cells toward the vitreoretinal side. CONCLUSION: The presence of an intact internal limiting membrane, the absence of optical fibers belonging to the under retina, and the absence of any sign of apoptosis make TB a useful staining agent for ERM and ILM peeling.

Aged↗

PubMed2005

[Evaluation of trypan blue toxicity in idiopathic epiretinal membrane surgery with macular function test using multifocal electroretinography: seven prospective case studies].

INTRODUCTION: Idiopathic epiretinal membranes are considered the consequence of glial proliferation through a defect of the internal limiting membrane and can induce a functional macular syndrome associating mainly metamorphopsia and visual acuteness. Visual disturbance is not bound to the area and the degree of transparency of the membrane, but to distortion of external layers of the retina. Multifocal electroretinography (ERGm) can assess the macular area and retina extending 20 degrees. We used this tool to study macular function pre- and post-operatively with seven patients presenting idiopathic epiretinal membrane. PATIENT AND METHOD: All patients had successful vitrectomy, with 0.2 ml of 0.15% trypan blue (TB) staining to facilitate peeling. This stain is not toxic for the pigment epithelium but it becomes so for photoreceptors at doses exceeding 0.2%. We tried to estimate the echo of TB 0.15% on photoreceptors through this exam. An ERGm was done 1 week before the operation as well as 1 month and 4 months after on 14 eyes of seven patients with ERMs. RESULTS: Results show a pre-operative decrease in the electrical retinal response densities in the foveal, perifoveal and parafoveal areas. One month after operation, no significant difference was found compared to pre-operative results. However, at 4 months, an improvement of the retinal response density was observed. Retinal response densities in the macular area increased progressively after ERM surgery. CONCLUSION: The 0.15% TB facilitated ERM peeling and does not seem to present any retinal toxicity.

Electroretinography↗

PubMed2005

[Role of trypan blue in epiretinal membrane surgery].

INTRODUCTION: Idiopathic epiretinal membrane (ERM) results from detachment of the posterior hyaloid. Vitrectomy and peeling are the treatment of choice. Trypan blue 0.15% (TB) stains the epiretinal membrane and the internal limiting membrane (ILM), facilitating surgery and thus allowing selective and complete removal with less retinal damage. We conducted a study evaluating the advantages of selective staining associated with surgery, the incidence of postoperative damage, and the influence on final visual acuity. MATERIAL AND METHODS: Fourteen patients were operated on by the same surgeon, who carried out a complete vitrectomy, then fluid-air exchange for dye injection of undiluted 0.2 ml of Trypan blue 0.15% in front of the membrane, which was then easily distinguished from the area under the retina. Preoperative visual acuity, postoperative damage, as well as eye status at the end of follow-up are discussed. Transmission electron microscopy was used to determine if epiretinal membrane removal was complete and selective. Angiography was systematically used to study the state of retina before and after surgery. RESULTS: Preliminary results show that trypan blue is useful and facilitates complete removal of ERM and ILM. It may reduce long-term complications and recurrent membrane formation. Trypan blue is a staining agent that is quick and easy to use. It presents no short-term toxic effects. Functional results in 6 months show improvement of visual acuity and disappearance of metamorphopsia. CONCLUSION: Idiopathic epiretinal membrane surgery with tryptan blue staining is a better alternative than indocyanine green staining.

Aged↗

PubMed2004

[Role of vitrectomy in patients with a decrease in visual acuity secondary to asteroid hyalosis].

PURPOSE: Asteroid hyalosis is a vitreous degeneration with calcium and phosphorus--lipid complexes in elderly patients with vascular risk factors or general disease such as diabetes mellitus. Synchysis scintillans is a complication of pathological eyes. Generally there are no symptoms. This study aims to evaluate the role of vitrectomy in patients with a decrease in visual acuity. CASE REPORTS: Pars plana vitrectomy was performed in three patients with visual acuity less than 1/10. The biomicroscope examination showed white and bright particles with rounded and variable shapes localized in the anterior vitreous, moving with the eye. The visualization of the fundus was difficult or impossible. On echography B, the vitreous was very dense with a complete posterior vitreous detachment. The vitrectomy was completed in one case by peeling an epiretinal membrane. Visual acuity was improved for two patients (6/10 or more) and stable for one patient with an atrophic DMLA. DISCUSSION AND CONCLUSION: These results were compared with studies in the literature: in spite of complications, vitrectomy can be indicated in patients with a substantial decrease in visual acuity. However, the result is conditioned by the macular status. Fluorescein angiography can, when it is possible, evaluate the fundus before surgery.

Aged↗

PubMed2003

[Leber's idiopathic stellate neuroretinitis: about two cases].

BACKGROUND: Described by Theodore Leber in 1916, this syndrome is characterized by unilateral visual loss, optic disc swelling and a stellate pattern of exudative deposits in the macula. MATERIAL AND METHODS: Two young adults were examined for sudden unilateral visual loss preceded by a flu-like syndrome. Fundus examination revealed a swollen optic disc and a macular star, visualized on fluorescein angiography. Visual field, laboratory tests and cranial and orbital tomodensitometry were performed. RESULTS: Visual field examination showed a centrocecal scotoma. Laboratory tests showed inflammatory syndrome in one case. Serology testing (leptospirosis, cat scratch disease, toxoplasmosis and syphilis, etc.) were negative. Tomodensitometry of the brain and orbits gave normal results. One of the patients was treated with intravenous steroid boluses; the other received no treatment. A few weeks after the beginning of symptoms, the swelling of the optic disc seemed to have declined, leaving the macular star unchanged. CONCLUSION: These two cases typically describe Leber's idiopathic stellate neuroretinitis. The prognosis for visual recovery is usually reported to be excellent, but visual sequelae have been described.

Adolescent↗

PubMed2002

[Endovascular treatment of sinus dural fistulas using vein catheterism].

PURPOSE: We report two techniques for treatment of dural arteriovenous fistulas using femoral vein catheterism and direct surgery via the superior ophthalmic vein. We will attempt to show the advantages of these new techniques instead of using the arterial pathway, which is currently the reference procedure. SUBJECTS AND METHOD: Mrs G, 75 years old was sent by her ophthalmologist because of a suspected orbital tumor. Visual acuity: right eye: 3/10, exophthalmia, chemosis, with no thrill or murmur. The fundus examination was normal. The ultrasound exam with color Doppler imaging showed an arterialization of the superior ophthalmic vein compatible with an arteriovenous sinus dural fistula. Angio-MRI revealed a large left cavernous sinus, confirming the diagnosis. Considering the type of the fistula and the weak physical condition of the patient, we decided to attempt an endovascular embolization with coil placement, using femoral vein catheterism. Exophthalmia regressed within days. The fistula remains sealed 1 year after the procedure. Mr D, 40 years old, showed a similar clinical aspect of sinus dural fistula. We attempted an embolization with the femoral vein, which failed. We decided to embolize the cavernous sinus via the direct surgical pathway of the superior ophthalmic vein. Coils were placed and the fistula was sealed. CONCLUSION: These clinical cases show two less invasive alternatives giving better results than arterial embolization, the reference method (Brooks 1930; Spearmann 1964; Parkinson 1965), endovascular trapping, or surgery.

Adult↗

PubMed1997

[Toxocara canis infection. 2 cases of peripheral granuloma in adults].

PURPOSE: We report two cases of toxocariasis peripheral granuloma in adults. METHODS: Diagnostic difficulties linked to parasite serologies, particular to these two cases, are presented. Serology is often poorly contributive, but PCA and/or vitreous study with the ELISA reaction to Toxocara canis homologous antigens in the endocular fluids are the most reliable means of reaching a diagnosis, as evidence in our two observations. In the same way, the presence of eosinophils and of IgE in the aqueous humor and or vitreous is of great importance for orienting the diagnosis. RESULTS: The treatment consisted in systemic steroids and granuloma cryotherapy associated with vitrectomy and for one case indentation due to a traction. Later, retinal membrane peel was performed for the same patient. No treatment with antihelminthic drugs was proposed. The functional and anatomic results were good in both cases (8/10-P2 and 6/10-P2). CONCLUSION: Toxocara canis infection is based on clinical aspects. The ELISA technique is useful for biological diagnosis.

Adult↗

PubMed1996

[Spatial contrast sensitivity in patients with severe myopia].

PURPOSE: The purpose of this study was to assess the effects of amount of myopia, axial elongation staphyloma and type of optical correction on contrast sensitivity of high myopic subjects. METHODS: Fifty-one patients (91 eyes) were selected on the following qualifications: myopia > or = 8 dpt and/or axial length > or = 26 mm, and visual acuity > or = 0.1 recorded through spectacle lenses. Contrast sensitivity was measured using a "Moniteur Ophtalmologique" for all subjects when corrected with spectacle lenses, and thereafter on a lot of patients (50 eyes) wearing a contact lens. RESULTS: Contrast sensitivity obtained with spectacle lenses was significantly decreased over the whole spatial frequency range. The higher the spatial frequency was, the lower contrast sensitivity was. The impairment increased with the amount of myopia and axial length, but without positive correlation. Contrast sensitivity was significantly lower for only the three highest spatial frequencies measured (6.4; 12.8 and 25.6 c/deg), when a staphyloma (n = 52) was present by comparison with results obtained for eyes without staphyloma (n = 39). Differences between the two situations (spectacle lens vs. contact lens) were not significant for eyes wearing daily spectacle lenses; conversely, for myopic subjects generally fitted with contact lenses, contrast sensitivity with contact lenses was significantly better than that measured with spectacles for the three highest spatial frequencies tested. CONCLUSION: This suggests that the decrease in contrast sensitivity measured in high myopia is related to defects in the optical and neuro-retinal systems.

Adult↗

PubMed1996

[True or supposed bacterial endophthalmitis. Study of anatomo-functional outcome apropos of 32 cases].

PURPOSE: Vision prognostic study depending on the germs and the therapic performed in bacterial endophthalmitis. METHODS: In a retrospective study over a period of 3 years (1991-1993), 32 cases of post surgery bacterian endophthalmitis were detected: 30 cases after cataract surgery (29 cases after extra capsular surgery and one case after intra capsular), one case after trabeculectomy and one case after keratoplasty. RESULTS: A risk factor was evidenced in 15.6% of the cases. Endocular samples were done in 68.75% of the cases. The positive rate was 36.4% showing a Staphylococcus in 5 cases out of 8 (62,5%). In 37.5% of the cases an intraocular antibiotic injection was associated to the anterior chamber punction. 40% of the cases contaminated with Staphylococcus regained a visual acuity of more than 3/10. For the two cases where a Streptococcus was isolated an evisceration was necessary. Our results show that a higher visual acuity was obtained when a posterior vitrectomy was performed. When the posterior vitrectomy was associated with a corticoid therapy, the visual prognostic was better. Thus, 71% of these cases regained a visual acuity of more than 3/10. CONCLUSION: Our results show that performing a posterior vitrectomy associated to a general corticotherapy within 48 hours from the bacterian endophthalmitis diagnosis would allow best vision improvement.

Adrenal Cortex Hormones↗

PubMed1995

[Search for bacterial contamination of the aqueous humor during cataract surgery with and without local antibiotic prophylaxis].

PURPOSE: Bacterial contamination of anterior chamber at the end of cataract surgery, was compared between two techniques: extracapsular extraction and phacoemulsification. The effectiveness of preoperative antibiotic eyedrops using Norfloxacine 0.3% (Chibroxine) was also evaluated. METHOD: The study focused on 101 patients grouped according to surgical technique and presence of preoperative antibiotic eyedrops. Conjunctival sampling was made the day prior the surgery, as well as in the operating room, after skin and conjunctival desinfection with povidone iodine in all the patients included in the study. Aqueous humour was collected at the end of surgery. RESULTS: Eight samples out of 101 were positive which represents 7.9% of the cases. In 75% of the cases, the anterior chamber aspirate showed a different germ or non-recurrent germ in the second conjunctival sample. None of the included patients developed endophthalmitis. The two most frequent pathogens were Propionibacterium acnes in 62.5% of the cases, and Staphylococcus epidermidis in 50%. Another pathogen was found in a culture environment: Micrococcus roseus. In two samples, two different bacteria grew: Propionibacterium acnes and Staphylococcus epidermidis. Whatever the surgical technique, no statistically significant bacterial contamination was found. There was no significant statistical difference between patients who had local antibiotic eyedrops and those who did not. CONCLUSION: This study confirms the poor reliability of local antibiotic eyedrops to prevent surgical contamination. Furthermore performing an anterior chamber aspirate at the end of the surgery for risk patients would help the physician identify the pathogens involved in endophthalmitis in order to begin antibiotic treatment as soon as possible.

Administration, Topical↗

PubMed1992

[Measuring visual field loss by automated perimetry in chronic glaucoma stabilized by trabeculectomy].

The progression of field loss was determined by Humphrey Automated threshold perimetry in the short and intermediate term after surgical trabeculectomy for chronic glaucoma: mean indices (MD, PSD et FOV) were studied before and after normalisation of the intraocular pressure. Risk factors such as secondary glaucoma, previous visual field defects and cardiovascular risk factors were significantly correlated to poor or bad progression of field loss: the mean variation of MD = +1.23 dB +/- 2.84 (p < 1.5%), the mean variation of PSD = 0.50 dB +/- 1.37 (p < 6%), but the mean variation of FOV was not significant; so 36% of field defects were improved, 42% were stabilized and 22% were aggravated. When the risk factors were absent, 86% of field losses were stabilised but when cardiovascular factors were present, only 64% were stabilised. These risk factors can also be used to ascertain the prognosis of post-surgical progression of visual field, as already shown in previous reports. Automated threshold perimetry was useful to study the visual field progression with standardized and reliable numerical parameters, allowing statistical computerised management of the patients with glaucoma.

Adolescent↗

PubMed1989

[Calculation of the implant: is it a useless luxury?].

Analysis of the means by which accuracy of intraocular lens power calculation could be improved with theoretical and linear regression formulas. The postoperative refractive errors with the lenses selected by the surgeon were compared with those observed with the emmetropic calculated power lenses and with a standard 20 diopters lens. A consecutive series of 100 eyes with less than 4.50 diopters of pre-operative myopia or hypermyopia, is evaluated. Postoperative refractive errors are out of the range -4; +4 diopters in 6% for standard lens, 4% for actually implanted lens, and 1% for emmetropic power calculated lens.

Algorithms↗

PubMed1989

[Effects of laser chorioretinal photocoagulation].

Laser-chorioretinal interactions depend on: non controllable parameters: spectral transmission, absorption of tissue, scattering of laser, distribution of ocular chromophores, thermal conductivity of tissue. They are important determinant of laser tissue effects. parameters that can be monitored by the physician: size of the spot, pulse duration, laser energy and laser wavelengths. Theoretical predictions of laser-tissue interaction with the choroid and the retinal agree with histological and clinical data. The choice of physical parameters of laser must be done in order to prevent adverse effects as to obtain researched therapeutic goal.

Choroid↗

PubMed1988