Biomedical subjects

B Cochener

Publications and source records attributed to B Cochener.

At least 19 recordsLinked to original sources

PubMed2006

[Post-traumatic orbital emphysema: a case report].

Orbital emphysema is often associated with orbital fracture or communication with paranasal sinuses. It is usually moderate but could be the cause of optic neuropathy or central retinal artery occlusion. We report a case of massive orbital emphysema with ocular hypertony and prethrombosis of the central retinal artery. Emergency surgical decompression performed by an ophthalmologist and an otorhinolaryngologist provided complete and prompt relief. The authors emphasize the importance of preventing nose blowing after orbital trauma or surgery.

Adult↗

PubMed2006

[Unilateral ocular ischemic syndrome in a diabetic patient].

PURPOSE: To report a case of ocular ischemic syndrome in a diabetic patient. METHODS: The patient's main complaint was an insidious unilateral decrease in visual acuity of the right eye. This diabetic 60-year-old patient presented numerous vascular risk factors. RESULTS: Diagnosis was suspected from the fundus examination and was confirmed on ultrasonic carotid imaging combined with MR angiography showing a significant internal carotid artery stenosis. CONCLUSION: This case should remind clinicians to be cautious when dealing with any asymmetric ophthalmological exam. The diagnosis of ocular ischemic syndrome has to be suspected in case of unilateral retinal ischemia.

Carotid Stenosis↗

PubMed2006

[GBR foldable anterior phakic intraocular lens with angular supports: a 3-year experience].

PURPOSE: The purpose of this study was to evaluate the efficiency, predictability, and safety of the GBR foldable anterior chamber implant with angular supports to correct high myopia after 3 years of follow-up. MATERIAL: and methods: A GBR anterior chamber lens with angular supports was implanted in 44 eyes between November 2001 and February 2004. These eyes were highly myopic (preoperative mean of -10.65 +/- 2.62 diopters (D) (range, -6.25 to -16.50 D). Visual acuity, refraction, biomicroscopy, and quality of vision were estimated with a follow-up of 3 years. The potential complications required endothelial density, mobility of the pupil, intraocular pressure, and gonioscopy measurements. RESULTS: No severe intra- or postoperative complications required an ablation of the lens. Increased intraocular pressure in three cases and decentration in one were the most serious side effects reported. Eighteen eyes (40.9%) presented pupil ovalization; 68.2% of the eyes reached the attempted correction +/-0.50 D. Implants seemed stable in their position and refractive results. Functional signs included night glare for eight patients (18.2%) and glare in the sun for 11 (25%). There was no significant decrease in cellular endothelial density mean during follow-up. CONCLUSION: The GBR implant (Ioltech) is the pioneer of foldable anterior chamber implants, a concept in full expansion. Long-term satisfaction of the operated patients is encouraging. However, the medium-term anatomical modifications noted require monitoring and a search for the responsible mechanism.

Adult↗

PubMed2006

[Fundus albipunctatus incidentally discovered in a black African man].

Fundus albipunctatus is a recessive autosomal disease classified as one of the causes of congenital stationary night blindness. It is characterized by early hemeralopia beginning in infancy. We report the incidental discovery of the disease in a 23-year-old black African man with late hemeralopia onset. During the 4 years of follow-up, visual acuity, ERG, and visual field remained normal. We underline the possibility of late hemeralopia onset and discuss the possible progressive features of this disease. Progression may be conditioned by the mutation of the RDH5 gene, which codes for retinol dehydrogenase-5.

Adult↗

PubMed2006

[Assessment of the Quantel Medical 20-Mhz Ultrasound Cinescan in intraocular measurements].

BACKGROUND AND OBJECTIVE: Evaluation of the Quantel Medical 20-MHz Ultrasound Cinescan using a closed transducer in intraocular measurements and its reproducibility. PATIENTS AND METHODS: We measured sulcus-to-sulcus distance of 40 control eyes using the20-MHz Cinescan. Then we compared the sonography to the Oculus Pentacam based on the Scheimpflug principle in the measurements of anterior chamber depth, cornea-to-implant distance, and implant-to-crystallin lens distance in patients who underwent phakic implantation (56 eyes). RESULTS: With this technique, the sulcus-to-sulcus distance can be measured with a reproducibility of 86%-88% (p<0.05). The authors show that the corneal diameter is not correlated with the sulcus measurement (R=24%, p<0.05). DISCUSSION: Several techniques are used to quantify anterior segment biometry. Some of these methods, such as White-to-White, are too empirical and others, such as the Scheimpflug camera - for example the EAS-1000 (Nidek) - or high-frequency ultrasound - Ultrasound BioMicroscopy UBM P45 (Paradigm) - are too expensive. The 20-MHz Cinescan has good reproducibility and provides easier access to anterior segment biometry. CONCLUSION: The 20-MHz Cinescan appears to be an accessible technique that may become a useful tool in the refractive surgery of the phakic intraocular lens.

Adult↗

PubMed2006

[Congenital anophthalmias: a case of trisomy 13].

Congenital anophthalmia is the result of a lack of development or regression of the primary optic vesicle in utero. It can be isolated or associated with other malformations and can be unilateral or, rarely, bilateral. Different etiologies are usually found such as chromosomal aberrations, gene mutations, toxic agents, and infections. We report a case of bilateral congenital anophthalmia in a setting of a polymalformative syndrome with microcephalia and bilateral lip cleft. Karyotype studies confirmed trisomy 13 known as Patau's syndrome. Trisomy 13 is a rare lethal chromosomal aberration frequently responsible for uni- or bilateral microphthalmia and occasionally for anophthalmia.

Abnormalities, Multiple↗

PubMed2003

[Non-biodegradable drug-sustained capsular ring for prevention of secondary cataract. Part I: In vitro evaluation].

PURPOSE: The appearance of secondary cataract constitutes the most common complication of cataract surgery since the advent of phacoemulsification. Prevention is today one of the most crucial challenges of research in ophthalmology. We have developed a drug-sustained capsular ring releasing 5-fluorouracil (5-FU). This system aims to combine mechanical and pharmacological properties with the ability to interfere on the lens epithelial cellular processes of secondary cataract. This first article will report on the in vitro evaluation of this system. MATERIALS AND METHOD: Development of a hydrogel that can serve as a mechanical support and as a release of an active agent requires a comparative trial of multiple hydrophobic products providing rigidity to the ring and of hydrophilic products providing the ability to release a drug. The choice of 5-FU as a non-proliferate agent was based on its well-known pharmacological properties and its wide use in ophthalmology. Evaluation comprised adjustment of the adequate copolymer, then of the loading phase, and finally assessment of 5-FU release. The mechanical characteristics and cytocompatibility of the ring were also assessed. RESULTS: The characteristics of drug release differed depending on the water content and resulting volume of the copolymer. The pharmaceutical and mechanical testing led to selecting the HPMA-MMA combination (75:25). However, a burst effect within the first 2 hours was observed in all cases. That limit was eliminated by creating a biodegradable surface coating of Poly Lactid-co-Glycolid (PLG 50:50) that could provide a positive barrier effect against migration and a controlled continual release of 0.25 microg/h extended to 9 days. Mechanical tests of tension, compression, and traction showed the crucial influence of the ring's hydration state. The cytocompatibility study showed no evidence of cellular toxicity. DISCUSSION/CONCLUSIONS: The synthesized copolymer is able to release a constant, regular and safe rate of 5-FU, higher than CI50 over a period of 9 days for a cell proliferation phase of 3-5 days. We adjusted the ring associating the mechanical properties and the ability to release 5-FU, allowing further evaluation on animal models, the subject of the second part of this report.

Biocompatible Materials↗

PubMed2003

[Nonbiodegradable drug-sustained capsular ring for prevention of secondary cataract. Part II: In vivo evaluation].

PURPOSE: The appearance of a secondary cataract constitutes the most common complication of cataract surgery since the advent of phacoemulsification. Prevention is today one of the crucial challenges of research in ophthalmology. We have developed a drug-sustained capsular ring releasing 5-fluorouracil (5-FU). This system targets the goal of combining advantageous mechanical and pharmacological properties with the ability to interfere on the epithelial cellular processes of secondary cataract. This paper presents the results of animal evaluation. MATERIAL AND METHODS: The study first developed the in vitro delivery system as a preliminary step to the animal in vivo approach. After a pilot study conducted on micro pigs, lens extraction was performed on the right eye of 22 female albino rabbits. The four study groups included: group 1 (6 animals) as a control group receiving only phacoemulsification; group 2 (6 animals) receiving phacoemulsification and the implantation of a nonsustained capsular tension ring; and group 3 (6 animals) receiving a drug-sustained ring. Group 4 (4 animals), implanted with a 5-FU-sustained ring, was reserved for staged samples of aqueous humor for kinetic determination of active agent release. RESULTS: Clinical evaluation based on biomicroscopy and histology showed a lesser reaction of secondary cataract in eyes with the ring. Compared to group 1, central posterior capsular opacification appeared significantly lower in density and surface in groups 2 and 3. No intraocular toxicity was observed. The poor sensitivity of the 5-FU detection method (high-performance chromatography) impaired pharmacokinetic evaluation. DISCUSSION CONCLUSIONS: The decrease in secondary cataract reaction in cases of implanted capsular ring demonstrated the advantages of its mechanical effect. However, the benefit of an additive pharmacological action related to the release of 5-FU could not be proved. Nevertheless, the theoretical concept of a drug-sustained delivery system seems attractive and thus calls for evaluation of other potential modulators of cell behavior.

Animals↗

PubMed2002

[Bilateral papilledema in young women: two case reports of benign intracranial hypertension?].

We report two cases of bilateral papilledema in young women. The first patient was 15 years old and had experienced headaches and vomiting for one month, but no visual loss. Cerebral tomodensitometry results were normal, but lumbar puncture showed increased pressure and normal biology. Benign intracranial hypertension was diagnosed. Recent treatment with minocycline for acne vulgaris was the only etiology. Papilledema was totally regressed at 6 weeks, after interruption of the antibiotic treatment. A prescription of acetazolamide was added for a short period of 10 days. The second patient, aged 29 years, presented bilateral papilledema with severe visual loss, with vision limited to light perception with mydriasis of the right eye. Lumbar puncture was not indicated because of a hypophyseal microadenoma revealed on MRI investigation. No other associated abnormalities were observed, in particular, no cerebral sinus thrombosis. Corticotherapy using prednisolone for 72 hours had no clinical effect. Fast visual recovery was obtained with intravenous acetazolamide therapy and was completely resolved at 2 months. Right visual field defects persisted. Minocycline and obesity are recognized as precipitating factors in pseudotumor cerebri syndrome. The literature advocates consideration of surgical treatment by optic nerve sheath fenestration if antiedematous treatment has no effect and the eye is nearly blind.

Acetazolamide↗

PubMed2001

INTACS inserts for treating keratoconus: one-year results.

OBJECTIVE: To evaluate the use of INTACS micro-thin prescription inserts (Kera Vision, Inc., Fremont, CA) for the treatment of keratoconus. DESIGN: Prospective, nonrandomized (self-controlled) comparative trial. PARTICIPANTS/INTERVENTION: Ten patients from our prospective clinical study who had completed 12 months of follow-up were evaluated. All patients had keratoconus with clear central corneas and were contact lens intolerant. After reviewing corneal pachymetry and topography of individual patients, INTACS inserts of 0.45-mm thickness were placed in the inferior cornea to lift the cone and INTACS of 0.25-mm thickness were inserted superiorly to counterbalance and flatten the overall anterior corneal surface. MAIN OUTCOME MEASURES: Differences between preoperative and postoperative uncorrected visual acuity, best spectacle-corrected visual acuity, manifest refraction, and keratometry values were statistically assessed. Changes in corneal ectasia were evaluated by reviewing corneotopographic maps. RESULTS: No intraoperative complications occurred in this series of patients. Spherical equivalent error and refractive astigmatism were reduced with INTACS inserts treatment. Postoperative month 12 uncorrected visual acuity (logarithm of the minimum angle of resolution [logMAR] mean, 0.35, standard deviation [SD], 0.16 [approximately 20/50, approximately 2 lines]) was significantly better than preoperative (logMAR mean, 1.05; SD, 0.33 [approximately 20/200, approximately 3 lines]; P <or=0.05). Average best spectacle-corrected visual acuity at postoperative month 12 was improved by approximately two lines compared with baseline (logMAR mean, 0.22; SD, 0.12 [approximately 20/32, approximately 1 line]; logMAR mean, 0.38; SD, 0.13 [approximately 20/50, approximately 1 line], respectively). Topographic corneal shape (size and height of the cone) was improved for all subjects after insert placement. CONCLUSIONS: INTACS micro-thin prescription inserts seem to provide a viable method for treating clear corneal keratoconus for patients who are contact lens intolerant. The corneal steepening and astigmatism associated with keratoconus were reduced, and visual acuity was improved with treatment in almost all eyes.

Adult↗

PubMed2001

[Motivation of candidates for refractive surgery].

PURPOSE: To determine the profile and motivations of patients who are candidates for refractive surgery. MATERIAL: and METHODS: We studied 102 patients with low myopia (less than 6 diopters) in a single-center investigation. RESULTS: Among the total population studied, the motivation for refractive surgery was essentially comfort and appearance. Fewer men wore contact lenses than women and had worn them for a shorter period of time. Those involved in sports were more often in individual sports. Contact-lens wearers were most often students or in the paramedical professions. DISCUSSION: The population interested in refractive surgery was very young. The proportion of candidates who had never worn contact lenses was surprisingly high. CONCLUSION: This analysis suggests that patients too often consider refractive surgery as an easy option.

Adolescent↗

PubMed2001

[Excimer surface photoablation versus Lasik for correction of mild myopia].

INTRODUCTION: Above -6 diopters, Lasik procedure has shown its superiority in term of predictibility, efficacy and stability. In the adverse, in the field of low myopia, Lasik and surface excimer photoablation (PRK) are very controversial. We compare quantitative and qualitative outcome achieved in series of 25 PRK operated patients and 25 Lasik. MATERIAL AND METHOD: 2 homogeneous groups were constituted: group A for Excimer patients and group B for Lasik. Initial ametropia had to be ranged between -2 and -6 diopters (D), eventually associated to a myopic astigmatism that needed to be under -1,75 D. Excimer laser model was a Visx (Visx 20/20 or Star S2). In case of Lasik, flap was performed with an Automated corneal shaper microkératom (Baush & Lomb) or with a Flap Maker (Ioltech). Evaluation of refraction and visual results was associated to measurements of contrast and glare sensitivities and collection of functional complaints. RESULTS: A retrospective analysis is performed with a 2 years follow-up. At that term, rate of eyes, that achieved 20/20 or better is comparable in the two groups (62% in group A and 64% in group B). However, profile of visual recovery goes faster after Lasik. Best corrected visual acuity is favorably preserved in two groups, but is altered with glare in Lasik group. Cycloplegic refraction shows a tendency to regression more important in case of surface ablation (10% versus 4%), especially above -4 D (28%). No significant difference is noted concerning contrast sensitivity, correctly unchanged in the two groups. No case of severe complication is mentioned after both surgical methods. DISCUSSION-CONCLUSION: In the field of low myopia, PRK and Lasik appear to guarantee same predictibility and safety, in conditions of preliminary learning curve. Stability and visual recovery are earlier achieved after Lasik, in addition to postoperative indolence. However, application of this technique to all degrees of myopia requires its perfect control and an adjustment of ablation nomograms.

Adult↗

PubMed2001

[Modeling the eye based on simulated refractive surgery].

PURPOSE: To achieve three-dimensional modelizing of the eyeball (morphological and mechanical behavior) in order to simulate the impact of various refractive surgery techniques and to study the normal and pathological states of the eye. METHOD: Rebuilding the ocular shell is based on different kinds of imaging (MRI, ultrasound) including information provided by video topography. Image data are treated using suitable numerized filters that allow automatic segmentations of ocular globus edges. Reconstruction is based on specific mathematical functions (B-splines). The mechanical behavior of a reconstructed model is simulated by solving equations of linearized elasticity with the finitude elements method. RESULTS: Numerous simulations mimmed different refractive surgical techniques and, then validated the model. In addition, simulations of various pathologies allowed us to verify certain clinical hypotheses. CONCLUSION: This work, although still experimental, demonstrates the advantages of such simulations and will allow novice physicians an easier approach to different surgical techniques and will help them understand their effect. Furthermore, it might be useful for simulation of new surgical concepts even before their in vivo evaluation.

Computer Simulation↗

PubMed2000

Comparison of the efficacy and safety of valaciclovir and acyclovir for the treatment of herpes zoster ophthalmicus.

OBJECTIVE: To compare the efficacy and safety of valaciclovir and acyclovir in immunocompetent patients with herpes zoster ophthalmicus. DESIGN: A multicenter, randomized, double-masked study. PARTICIPANTS: One hundred ten immunocompetent patients with herpes zoster ophthalmicus diagnosed within 72 hours of skin eruption were treated; 56 were allocated to the valaciclovir group and 54 to the acyclovir group. METHODS: Patients randomized to the valaciclovir group received two 500-mg tablets of valaciclovir three times daily and one tablet of placebo twice daily. Patients in the acyclovir group received one 800-mg tablet of acyclovir five times daily and one tablet of placebo three times daily for 7 days. MAIN OUTCOME MEASURES: Main outcome measures included the frequency, severity, and duration of ocular complications, patient reports of zoster-associated pain, and the outcome of skin lesions. Tolerance was also assessed on the incidence and types of adverse effects and changes in laboratory parameters. The analysis was mainly descriptive and performed on an intent-to-treat basis. RESULTS: Ocular complications of herpes zoster ophthalmicus were similar in the valaciclovir and acyclovir treatment groups. The main complications were conjunctivitis (54% and 52%, respectively), superficial keratitis (39% and 48%, respectively for punctate keratitis; 11% in each group for dendritic keratitis), stromal keratitis (13% in each group), and uveitis (13% and 17%, respectively). The long-term outcomes of these ocular complications were favorable and similar in both treatment groups. Pain duration and severity and outcome of skin lesions were similar between groups. Most patients reported prodromal pain. After 1 month, 25% of patients in the valaciclovir group and 31% in the acyclovir group still reported pain. The percentage of patients experiencing postherpetic neuralgia decreased during follow-up. The tolerance to acyclovir and valaciclovir was comparable and considered good. The most frequent adverse events were vomiting and edema of the eyelids or face (3%-5%). Three serious adverse events not linked to the study drugs occurred. CONCLUSIONS: Valaciclovir is as effective as acyclovir in preventing ocular complications of herpes zoster ophthalmicus, including conjunctivitis, superficial and stromal keratitis, and pain. Tolerability of the two drugs is similar, but the dosing schedule of valaciclovir is simpler.

Acyclovir↗

PubMed2000

Correcting keratoconus with intracorneal rings.

PURPOSE: To evaluate the potential of intrastromal corneal ring technology (Intacs, KeraVision) to correct keratoconus without central corneal scarring. SETTING: Department of Ophthalmology, Brest University Hospital, Brest, France. METHODS: In this prospective, noncomparative, interventional case series, Intacs segments were implanted in 10 keratoconic eyes with clear central corneas and contact lens intolerance after corneal pachymetry was checked. Segment thicknesses varied based on corneal topography analysis. RESULTS: No intraoperative complications occurred. The mean follow-up was 10.6 months. Postoperative results revealed a reduction in astigmatism and spherical correction and an increase in topographical regularity and increased uncorrected visual acuity. CONCLUSION: Intacs technology can reduce the corneal steepening and astigmatism associated with keratoconus.

Adult↗

PubMed2000

Effect of intrastromal corneal ring segment shift on clinical outcome: one year results for low myopia.

PURPOSE: To evaluate the effect of intrastromal corneal ring segment (ICRS) shift on clinical outcome. SETTING: Chu Morvan Ophthalmology Service, Brest, France. METHODS: Forty-seven eyes with myopia from -1.0 to -5.0 diopters (D) had ICRS surgery according to United States Food and Drug Administration protocol using a 2-segment implant design. Visual acuity, refractive, videotopographic, and biomicroscopic results in eyes that did not have contact between segments (Group A, n = 26) and in eyes that did have contact (Group B, n = 21) were compared. RESULTS: Soon after surgery, migration of and subsequent contact between the implant segments occurred in 21 eyes (45%). Contact between the inferior ends was most common, occurring in 19 eyes; in the remaining 2 eyes, the superior ends of the implant touched. Superior contact was associated with superficial channels, wound-healing problems, and ICRS explantation. No segment shift was observed after the first postoperative week. No significant differences in visual acuity, qualitative vision, or density of intrastromal deposits were noted between the 2 groups. However, at 6 months there was more induced with-the-rule cylinder in Group B (mean +1.3 D +/- 0.7 [SD]) than in Group A (mean +0.7 +/- 0.5 D). Astigmatism was clinically significant in only 3 cases at 3 months. CONCLUSIONS: Induced cylinder remains a limitation of the ICRS procedure, and segment contact appears to influence the rate of induced cylinder. Overall, however, the ICRS procedure produces promising results. Research efforts are underway to address induced cylinder and channel deposits associated with ICRS surgery.

Adult↗

PubMed2000

[Indomethacin (indocollyre) versus diclofenac (voltarene) for the control of pain following excimer photoablation].

PURPOSE: To compare effect of two topical non steroidal anti-inflammatory (NSAI) drugs: Indomethacin (Indocollyre)0.1 %, Chauvin Inc.) and Diclofenac (Voltaren 0.1%, Cibavision) on postoperative pain and epithelial regrowth following surface excimer photoablation. MATERIAL AND METHOD: Eighty-six excimer operated patients, were divided in two similar groups depending on the NSAI instilled postoperatively and for 3 days (4 drops daily). No patient was informed of any other available drug. Pain intensity was quantified between 1 and 10 according to an analog scale (reported from 1 to 10 hours, then 4 times a day during 7 days). Complementary medications and functional symptoms were also notified. Biomicroscopic evaluation using fluorescein test was performed to assess reepithelialization. RESULTS: In term of pain, no significative difference was observed between the two groups concerning intensity, associated medications, or numbers of days of discomfort. Controversially, retreated eyes might induce more pain than initial treatments. No delay in epithelial regrowth was noted and the difference between the two groups in functional complaints was no statistically significant. Pain appears to be not related to ablation depth. DISCUSSION- CONCLUSION: Our results are correlated to literature reported data. Introduction of NSAI constitutes a real advent in the care of excimer postoperative pain. Effect of indomethacin seems comparable to diclofenac effect, but might be of interest because of no anesthetic property that might guarantee of no delay in wound healing response.

Adult↗

PubMed2000

[Excimer photorefractive keratectomy (PRK) versus intrastromal corneal ring segments (ICRS) for correction of low myopia].

PURPOSE: Theoretical differences between ablative and additive surgeries are obvious, but what about final outcome? We decide to compare surface excimer photorefractive ablation (PRK) with Intracorneal segments (Intacs or ICRS) for correction of low myopia. MATERIAL: and METHOD: Two homogeneous groups of 25 low pure myopic patients were considered: group A including patients operated with Excimer and group B corresponding to Intacs implanted eyes. Retrospective analysis was performed and compared data achieved at two years follow-up, in term of refractive results and qualitative vision. RESULTS: Considering non corrected visual acuity, percentages of eyes who achieved 20/40 or better are comparable in the two series (respectively 97% in group A and 99% in group B). In the adverse, proportion of patients achieving 20/20 or more is superior in Intacs group (77%) versus 62% in PRK group. In all cases, quality of vision is altered in early postoperative period, then returns to normal between 1 and 3 months. Functional complaints appear more frequent and persisting in intrastromal segments group. Based on videotopography and cycloplegic refraction, it seems that risk of induced astigmatism occurrence is significantly increased in case of Intacs. No severe complication is mentioned in both groups. DISCUSSION CONCLUSION: Final outcome are in favor of the efficacy, safety and predictability of the two methods for correction of low myopia. Concept of Intacs presents the interest of potential adjustability and respect of central corneal area; however it appears to be limited by the occurrence of an induced astigmatism.

Adult↗