Biomedical subjects

Gérard Brasseur

Publications and source records attributed to Gérard Brasseur.

7 recordsLinked to original sources

PubMed2006

Evaluation of macular changes before and after successful retinal detachment surgery using stratus-optical coherence tomography.

PURPOSE: To assess preoperative and postoperative infra-clinical macular changes in macula-off retinal detachment (RD) using third-generation optical coherence tomography (OCT3). DESIGN: Prospective observational cohort study. METHODS: Twenty-two nonconsecutive eyes of 22 patients with macula-off RD underwent best-corrected visual acuity measurement and OCT3 scans through the fovea before and after successful surgery. The relationship between preoperative and postoperative OCT macular characteristics, postoperative infra-clinical foveal detachment, and final visual acuity (FVA) were assessed using Kruskal-Wallis multiple comparison test and Mann-Whitney U test, respectively. RESULTS: Preoperative cystic cavities in the inner nuclear layer of the detached retina, postoperative abnormal macular profile, and postoperative lack of the junction line between photoreceptor cell inner and outer segments on OCT3 were associated with a poorer FVA (P = .001, P = 10(-4) and P = .015, respectively). In contrast, postoperative infra-clinical foveal detachment did not influence FVA (P = .88). CONCLUSIONS: Morphologic macular analysis using OCT3 provide some new insights to understand incomplete visual recovery after successful macula-off RD surgery.

Adult↗

PubMed2006

A keratitis rat model for evaluation of anti-Acanthamoeba polyphaga agents.

PURPOSE: To develop a rat model of chronic Acanthamoeba polyphaga keratitis suitable for pharmacologic assessment of therapeutic agents. METHODS: An A. polyphaga isolate (ATCC #50495) was grown in peptone-yeast extract-glucose medium. Five-weeks-old, Sprague-Dawley male rats were injected with 10(3) or 10(4) trophozoites in the left cornea stromal layer. A subconjunctival injection of 0.14, 0.28, or 0.57 mg long-acting betamethasone was performed weekly. At the end of experiments, rats were killed; the superficial corneal epithelium gently scraped and cultured; and globes histologically examined. Topical polyhexamethylene biguanide (PHMB), hexamidine diisethionate, and miltefosine (hexadecylphosphocholine) were administered topically as eye drops 3 times a day at concentrations of 0.02%, 0.1%, and 0.01% respectively. In vitro minimal inhibitory concentration (MIC) and fractional inhibitory concentration values were measured in A. polyphaga cultures. RESULTS: In infected eyes, lesions consisted of the sequential appearance within 2 weeks of edema, infiltrates, and/or abscesses. On day 35 postinfection, a combination of 10(4) parasites with a regimen of 0.28 mg/week betamethasone resulted in the highest ratio of rats with abscesses. Presence of A. polyphaga was confirmed histologically and inconsistently in cultures. In rats optimally prepared as said earlier, agents were administered on day 6 postinfection. A combination of PHMB and hexamidine diisethionate exerted a synergistic effect and was more effective than PHMB, hexamidine diisethionate, or miltefosine alone. In vitro, PHMB (MIC = 14.6 microM) and hexamidine diisethionate (MIC = 555 microM) exerted a synergistic effect (fractional inhibitory concentration = 0.06), and miltefosine exhibited antiamoebal activity (MIC = 27.4 microM). CONCLUSIONS: In this study, a rat model of chronic A. polyphaga keratitis was obtained and found suitable for assessment of pharmacologic agents. It provides an in vivo approach of drug resistance, pathogenicity, and physiopathologic mechanisms of chronic amoebic keratitis.

Acanthamoeba↗

PubMed2005

Predictive visual outcome after macula-off retinal detachment surgery using optical coherence tomography.

PURPOSE: To determine whether preoperative optical coherence tomography (OCT) is useful in predicting postoperative visual outcome for patients with primary macula-off rhegmatogenous retinal detachment (RD). METHODS: This prospective study included 20 nonconsecutive eyes with macula-off RD and successful reattachment of the retina. Preoperative 5-mm OCT was performed through the center of the fovea. The relationship among preoperative OCT findings, main preoperative clinical variables, and final postoperative visual acuity was statistically analyzed. RESULTS: Final postoperative visual acuity was negatively correlated with three preoperative OCT variables: height of RD at the central fovea (r=0.79; P <0.001), distance from the central fovea to the nearest undetached retina (r=0.75; P <0.00051), and, to a lesser degree, extent of structural changes in the detached retina (r=0.48; P=0.03). Preoperative visual acuity was the only clinical variable statistically correlated with final postoperative visual acuity in this study (r=0.55; P=0.01). Using multivariate logistic regression analyses, the structure of the detached retina combined with the distance from the central fovea to the nearest undetached retina, as determined with OCT, was highly correlated with final postoperative visual acuity (r=0.82; P <0.000051). CONCLUSION: Preoperative macular analysis with OCT may help to predict visual outcome for patients with macula-off RD.

Adult↗

PubMed2004

Sub-Tenon infiltration or classical analgesic drugs to relieve postoperative pain.

BACKGROUND: In a prospective randomized double-blind study, the analgesic effect produced by sub-Tenon infiltration was compared with classic analgesic drugs in patients scheduled for posterior segment surgery under general anaesthesia. METHODS: One hundred patients were randomized into two groups of 50. One group received sub-Tenon infiltration (group 1) with 3 mL of bupivacaine 0.50% by the surgeon before the end of the surgery and the other (group 2) received only classical analgesic drugs postoperatively. A visual analogue scale (VAS) (graded from 1 to 10) was used to assess pain. For both groups, when VAS was between 1 and 3 paracetamol (3 g/24 h) associated with ketoprofen (200 mg/24 h) was given; between 3 and 6 nalbuphine (0.2 mg/kg slowly intravenously repeated every 4 h if necessary) was given; and over 6 morphine was given. Morphine 1 mg was injected every 2 min until VAS below 3 was obtained. RESULTS: All patients in group 2 (control) experienced pain in the recovery room period; however, no patient in group 1 required analgesic drugs in the first 6 h after the sub-Tenon infiltration. In the recovery room period, the VAS pain score in patients who received sub-Tenon infiltration (group 1) was 0.6 +/- 1.3 (mean +/- SD) compared to 3.4 +/- 2.2 in group 2. The difference was statistically significant (P = 0.000001). All patients in group 2 asked for analgesic drugs in the recovery room, some of whom required morphine. Despite the administration of drugs the pain score was statistically higher in group 2. Between the end of the recovery room period and the 6th hour, the VAS pain score in group 1 was statistically lower. From the 6th until the 24th hour, the pain score was not statistically significantly different between the groups. Regarding consumption of analgesic drugs from the recovery room until the 24th hour, the consumption of level 1 analgesic drugs (paracetamol, ketoprofen) and level 3 (morphine) was statistically lower in group 1 (P = 0.0009). The difference was not significant for level 2, probably because the number of patients was not sufficient. CONCLUSION: Sub-Tenon infiltration with 3 mL of bupivacaine 0.50% offers excellent postoperative analgesia for about 6 h and is an excellent alternative to classical drugs. Furthermore, it is highly reliable and safe.

Adult↗

PubMed2003

Long-term results of penetrating keratoplasty. A 10-year-plus retrospective study.

BACKGROUND: The aim of this study was to retrospectively analyse the outcome of a series of grafted patients over a period of more than 10 years and to determine their long-term survival probability. METHODS: The records of 89 patients who had 103 grafts performed in 97 eyes were analysed. Mean follow-up was 12.8 years (range 10-17 years). Life table analysis (Kaplan-Meier) was used to evaluate the graft survival of the total population and of different groups. RESULTS: Eighteen out of 89 patients (20.2%) had died. At the last visit before their death, 10 of the 21 grafts in those patients were still clear. Graft survival rates after 1, 2, 5 and 10 years were 79%, 73%, 59% and 50%; the rate at the end of follow-up was 47%. Survival rate at the end of the study was 94.7% for keratoconus, 57.1% herpes keratitis, 33.3% for pseudophakic keratopathies, 28.5% for post-traumatic keratopathies and 11.1% for re-grafts. In the group of patients grafted for aphakic or pseudophakic keratopathy, 40% died during the study. In 45% of cases their grafts were clear at the time of death. Endothelial decompensation and definitive graft rejection were the main causes of failure. CONCLUSIONS: The outcome of keratoplasty is progressively getting worse with time in pseudophakic or traumatic keratopathies whereas survival rates are still stable from 10 to 17 years in grafts performed after keratoconus or herpetic keratitis.

Adolescent↗

PubMed2002

Deep lamellar keratoplasty combined with cataract surgery.

We used a surgical technique that combines deep lamellar keratoplasty, phacoemulsification, and intraocular lens implantation for treating patients with cataract and corneal stromal disease. Deep lamellar dissection of the cornea was first performed with viscoelastic substances (hyaluronate sodium) until the highly transparent Descemet membrane solely remained. We then created a short corneal tunnel to perform phacoemulsification with low vacuum and intraocular lens implantation. The resilience of the Descemet membrane ensured excellent viewing of the whole anterior chamber as well as the surgical conditions of a closed system. At the end of surgery, a full-thickness donor button was sutured into the recipient bed after its Descemet membrane was stripped. This technique was effective in these 4 patients with cataract and dense corneal opacity.

Adult↗

PubMed2002

Peribulbar anaesthesia using a combination of lidocaine, bupivocaine and clonidine in vitreoretinal surgery.

PURPOSE: The efficacy and safety of peribulbar anaesthesia was assessed using a combination of lidocaine, bupivacaine and clonidine during eye surgery. METHODS: We prospectively studied 100 vitreo-retinal surgical procedures performed by several surgeons. The exclusion criteria included age below 30 years and, axial length of the orbit above 28 mm. Peribulbar was performed using Hamilton's technique. A mixed anaesthetic solution of equal quantity of lidocaine 2% and bupivacaine 0.5% with clonidine (1 mg/kg) was injected. Patients received a mean volume of 14.5 ml +/- 3.5 of the mixture. Akinesia and analgesia were assessed 15 minutes later by the surgeon. Whenever required, supplemental lidocaine 2% (3 ml) by sub-Tenon infiltration was added by the surgeon. Supplemental injections were given only to patients who failed to develop analgesia. RESULTS: The mean age of patients (male 52%, female 48%) was 66 years +/- 10 (mean +/- SD, range 44-90). The 100 surgical procedures were made up of vitrectomy +/- gas +/- silicone oil (22/100), vitrectomy and lensectomy (6/100), vitrectomy and epiretinal membrane +/- laser coagulation +/- gas +/- silicone oil (35/100), scleral buckling or encircling +/- gas (36/100), and cryosurgery +/- gas (1/100). Analgesia was adequate throughout surgery without any supplementation in 85% of cases and with a sub-Tenon infiltration in 99%. Akinesia was complete in 84%, mild in 12% and absent in 4% of cases. The sub-Tenon injection was performed in 15% of cases. Three patients (3%) were agitated during surgery. No neurologic or cardiac complication was seen. In one patient, the systolic blood pressure decreased from 170 to 110 mmHg, 30 minutes after the institution of the peribulbar block. CONCLUSION: Our results show that peribulbar anaesthesia in the proposed mixture offers excellent analgesia in 85% of patients, and in 99% of the patients when supplemented by a subtenon injection. The current mixture of lidocaine, bupivacaine and clonidine is an excellent alternative to the previously used mixture etidocaine, bupivacaine and hyaluronidase for vitreoretinal surgery. However, a randomized controlled clinical trial is needed to prove the efficacy and safety of these results.

Adult↗