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Biomedical subjects

J Colin

Publications and source records attributed to J Colin.

At least 37 records · Page 2Linked to original sources
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↗
PubMed1999

Retinal detachment after clear lens extraction for high myopia: seven-year follow-up.

OBJECTIVE: To prospectively evaluate the incidence of complications, particularly retinal detachment, 7 years after clear lens extraction (CLE) for myopia greater than -12 diopters (D). DESIGN: Extended follow-up of noncomparative case series. PARTICIPANTS: Fifty-two eyes of 30 patients with preoperative myopia greater than -12 D, best-corrected visual acuity (BCVA) of 20/100 or better, and intolerance of contact lenses. INTERVENTION: Patients with lattice degeneration, retinal tear, or hole underwent photocoagulation before CLE. The authors performed phacoemulsification through a 3.2-mm-wide incision using primary irrigation and aspiration, widened the incision to 6.5 mm, and implanted a one-piece polymethyl methacrylate intraocular lens (IOL). MAIN OUTCOME MEASURES: The BCVA, uncorrected visual acuity (UCVA), stability of spherical equivalent (SE), neodymium:YAG (Nd:YAG) capsulotomy rate, and complications (especially retinal detachment). RESULTS: At 7 years, the SEs of 29 eyes (59.1%) were within +/-1.0 D of emmetropia and 42 eyes (85.7%) were within +/-2.0 D. Mean SE was -1.01 D (+/-0.94). At 7 years, mean UCVA was 20/80 compared with 20/66 at 1 year. BCVA and UCVA were better in eyes with open capsules versus intact capsules. During the 7 years, 30 eyes (61.2%) required capsulotomy for opacification. Mean time for capsulotomy was 48.4 months after CLE. The authors performed ten argon laser retinal treatments after surgery, with all but one in the first postoperative year. The overall incidence of posterior vitreous detachment was 16.3%. The incidence of retinal detachment during the 7 years was 4 of 49 eyes, or 8.1% (vs. 2.0% at 4 years). One patient had bilateral retinal detachments. CONCLUSION: Despite advances in surgical technique, retinal detachment remains a major concern after CLE for high myopia. In the authors' series, the incidence of retinal detachment after CLE was nearly double that estimated for persons with myopia greater than -10 D who do not undergo surgery. Although CLE has advantages, including rapid and predictable visual rehabilitation, stable refraction, the ability to replace the IOL, and often superb optical quality with no irregular astigmatism, it is invasive and can result in severe vision loss. Long and continuous follow-up of the outcomes of CLE for high myopia is absolutely necessary before the authors can consider CLE as a routine option for patients with high myopia.

Adult↗
PubMed1999

Capsule contraction after continuous curvilinear capsulorhexis: poly(methyl methacrylate) versus silicone intraocular lenses.

PURPOSE: To evaluate the progressive contraction of the anterior capsule opening after in-the-bag implantation of 2 types of intraocular lenses (IOLs). SETTING: Department of Ophthalmology, University of Brest, Brest, France. METHODS: In this prospective study, 32 single-piece poly(methyl methacrylate) (PMMA) (Pharmacia 812 C) and 30 3-piece silicone IOLs with PMMA haptics (Allergan SI-40NB) were implanted in the bag after standardized phacoemulsification performed by the same surgeon. All patients were older than 70 years, and none had zonular weakness. The surface of continuous curvilinear capsulorhexis (CCC) was measured 1, 30, and 150 days postoperatively using a 3 charge-coupled device camera and a digitized computer analysis system. RESULTS: A significant progressive constriction was observed at 150 days in 70% in the silicone group and 32% in the PMMA group. In addition, CCC contraction was greater in silicone group (P < .05). The mean surface decrease was 4.20 mm2 in the silicone group and 1.53 mm2 in the PMMA group. There was no correlation between sex, age, initial capsulorhexis area, final capsule shrinkage. In some eyes, especially in those with a single-piece PMMA IOL (41%), there was no constriction, but fine changes in the capsule opening were seen. CONCLUSION: Evolutive anterior capsulorhexis modifications were observed in all patients; however, the contraction rate was statistically higher in the silicone group. These results suggest that silicone IOL implantation should be avoided in eyes at risk for CCC constriction.

Aged↗
PubMed1999

Conjunctival epithelial neoplasias in organ transplant patients receiving cyclosporine therapy.

PURPOSE: To report two cases of conjunctival epithelial neoplasias occurring after long-term systemic cyclosporine therapy in organ transplant recipients. METHODS: Case report. Each patient underwent an excision of an extensive limbal conjunctival lesion, followed by a histopathologic analysis. RESULTS: Histopathologic examination results revealed a carcinoma in situ and a squamous cell carcinoma in patients 1 and 2, respectively. Recurrence occurred in patient 1, who needed topical mitomycin C 0.02% treatment. No recurrence was observed in patient 2 after a follow-up of 24 months. CONCLUSION: To our knowledge, these are the first reported cases of its kind after longterm systemic cyclosporine therapy. Further studies will be needed to determine the exact role of cyclosporine in the induction of conjunctival epithelial neoplasias and the need for regular ophthalmologic examination of transplant recipients.

Carcinoma in Situ↗
PubMed1999

[Prostatic abscesses: what treatment to propose?].

Microscopic abscesses of the prostate (< 1 cm) are usually treated by antibiotics with good prostatic diffusion, such as fluoroquinolones, for a minimum of 4 to 6 weeks. Complementary surgical drainage is generally required for larger abscesses or in case of an unfavourable course. The main points of discussion in the literature are the type of drainage and the incision that should be performed. Prostatic abscesses used to be drained via perineal incisions, but with a high mortality. The use of effective antibiotics has significantly improved the morbidity of prostatic abscesses. CT-guided percutaneous drainage (perineal or transrectal), or more frequently transrectal ultrasound-guided drainage, now allows rapid and effective evacuation of the abscess, without the need for general anaesthesia. The perineal route allows a simple J stent to be left in place for several days to ensure complete drainage, but it is not universally accepted. Transurethral exposure is indicated for periurethral prostatic abscesses.

Abscess↗
PubMed1999

[Mixed retinal thrombosis in a patient carrying prothrombin gene mutation in a homozygote state].

We reported a case of a thrombosis of the retinal and central artery and vein in a 44-year-old patient, with high-grade T-cell lymphoma. Cardiovascular family history and a medical history of cerebral ischemia caused by in situ fibrinolysis, led to perform thorough hematologic and genetic examinations. These disclosed a prothrombin gene G 20210 a variant in a homozygous state. In a heterozygous state, this mutation leads to an increase in plasma prothrombin rate of the order of 30%. Therefore, it is considered to be a major risk factor for venous thrombotic disease. Otherwise, acute leukemia or non-Hodgkin's lymphoma may induce thrombosis of retinal artery and vein by means of an optic nerve infiltration, as well as beta-thalassemia, ocular trauma and retrobulbar anesthesia. Retinal central artery and vein are seldom both involved; whereas occlusions of their branches are more frequent.

Adult↗
PubMed1998

Excimer laser treatment of myopic astigmatism. A comparison of three ablation programs.

OBJECTIVE: The purpose of the study was to evaluate the precision, accuracy, and safety of three different modes of excimer laser surgery for myopic astigmatism. DESIGN: A prospective interventional case series. PARTICIPANTS: A total of 150 eyes with compound myopic astigmatism were treated. INTERVENTION: Ablation programs included the VISX Twenty/Twenty excimer laser using either the sequential mode (58 eyes) or the elliptical mode (54 eyes) and the Technolas-Chiron Keracor 116 hybrid scanning laser (38 eyes). MAIN OUTCOME MEASURES: Reduction in cylinder and sphere, vector analysis (polar values), uncorrected visual acuity, and best spectacle-corrected visual acuity were evaluated at 1, 6, and 12 months. RESULTS: By 12 months, sphere was reduced by 95.1%, 87.7%, and 75% in low-astigmatism eyes treated with the VISX sequential, VISX elliptical, and Technolas modes, respectively, and by 92.2%, 98%, and 77.6% in high-astigmatism eyes. By 12 months, cylinder was reduced by 51.5%, 72.2%, and 36.3% in low-astigmatism eyes and by 70%, 78%, and 45.6%, respectively, in high-astigmatism eyes. Vector analysis showed that the elliptical treatment produced more significant reductions in mean polar values than the other two treatments at various timepoints. CONCLUSION: These results suggest that the ablation approach may influence the clinical result.

Adult↗
PubMed1998

Penetration of piperacillin into the vitreous after intravenous administration.

PURPOSE: Penetration of piperacillin into the vitreous cavity after intravenous administration was investigated in humans. METHODS: Forty-five eyes undergoing vitrectomy between November 1993 and December 1994 were included. Each patient received a single intravenous dose of piperacillin 4 g 2 hours before ocular incision. A 0.2-mL vitreous sample was aspired at the beginning of vitrectomy, a blood sample was obtained, and piperacillin level was assessed. RESULTS: There were no detectable drug concentrations in 25 eyes. Mean vitreous drug concentration in the remaining evaluable eyes (n = 14) was 2.33 microg/mL (+/-0.76). We divided samples into two groups: 23 uninflamed (Group 1) and 16 inflamed (Group 2) eyes. Mean vitreous drug concentration was 0.42 microg/mL in Group 1 and 4.95 microg/mL in Group 2 (P < 0.2). Piperacillin concentration was higher than the minimum inhibitory concentration for gram-positive bacteria in 13% of uninflamed and 69% of inflamed eyes (P < 0.001). CONCLUSION: Studies show that intravenously administered piperacillin can penetrate the vitreous cavity in rabbits. Our study suggests that a single dose of piperacillin can produce intravitreal concentrations sufficient to kill gram-positive bacteria in inflamed eyes. The poor intraocular penetration of systemically administered piperacillin in uninflamed eyes raises questions about its usefulness as a prophylactic agent in ophthalmic surgery.

Adult↗
PubMed1998

Massive gross hematuria in a sickle cell trait patient with renal papillary necrosis. Conservative approach using a balloon ureteral catheter to tamponade the papilla bleeding.

We report the case of a patient with heterozygous sickle cell trait presenting with massive gross hematuria. Ureteroscopy revealed bleeding from the tip of papilla of the inferior calica and allowed us to tamponade the bleeding with a balloon ureteral dilator set (Cook(R) Urology). We show the value of the endourological approach in the conservative management of these patients at high risk of recurrent hematuria.

Adult↗
PubMed1998

[Intra-corneal rings for the correction of weak myopias].

OBJECTIVES OF THE STUDY: Intra-stromal rings (ICR) represent a new method for low myopic correction. An indirect central flattening is induced by a peripheral steepening related to the segments. This surgery was recently approved in Europe, but is still under evaluation in the multicenter study controlled by the FDA (Food and Drug Administration). We took part in that protocol and report our results at one year follow-up. MATERIAL AND METHOD: Twenty-five patients were included in the study with 47 operated eyes and a follow-up between 3 to 18 months. Data relative to refractive results, quality of the vision and anatomic changes induced by intrastromal segments will be collected at the issue of a rigorous survey. RESULTS: At one year, non-corrected visual acuity was 20/40 or better in 100% and 20/20 in 60%. We noted no loss in best visual acuity and an improvement of one or two lines in 20% of operated eyes. No significative changes were observed concerning: intraocular pressure, corneal sensitivity, central pachymetry or corneal endothelium. Three eyes had to be explanted and recovered the preoperative refraction. No severe complications were observed. DISCUSSION: Analysis of results is in favor of the efficacy, predictability and reproductibility of the surgery, which might be better with rings of a diameter under 0.40 mm. Occurrence of postoperative astigmatism appears to constitute the main limit suggesting discussion on etiologic factors and modalities of treatment. CONCLUSION: This concept of intra-corneal rings appears particularly promising for correction of low myopia and maybe in the near future for correction of others ametropia, requiring design of new specific segments. Essential interest of this surgery is the respect of the central area and its potential reversibility.

Adult↗
PubMed1998

[Primary renal chondrosarcoma: apropos of a case].

The authors report a case of primary renal chondrosarcoma associated with subcapsular renal haematoma. The authors reviewed the four largest series of renal sarcomas reported in the literature and propose an analysis of the various clinical characteristics, complementary investigations and treatment modalities of this exceptional form of renal sarcoma.

Aged↗
PubMed1998

[Current role of coagulase-negative staphylococci in urology].

Coagulase-negative Staphylococci (CNS), considered for many years to be commensal bacteria of the skin are now recognized as major agents of nosocomial infection. Bacterial factors (increased resistance), host factors (immune status) and multiplication of the portals of entry (presence of foreign material) have contributed to the increased incidence of nosocomial infections. The importance of the role of NCS in urology is due to their great capacity to colonize catheters and most prostheses. The particular organization of these bacteria into a conglomerate called biofilm is responsible for prosthetic infections, which can impair renal function and can sometimes be life-threatening. The authors review the current increase of the number of CNS isolated in urology departments and describe the various therapeutic strategies that can be proposed to eradicate these bacteria.

Cross Infection↗
PubMed1997

Clear lensectomy and implantation of a low-power posterior chamber intraocular lens for correction of high myopia: a four-year follow-up.

PURPOSE: To evaluate the 4-year postoperative outcomes of patients who are highly myopic who underwent clear lensectomy via phacoemulsification and low power posterior chamber intraocular lens implantation. METHODS: The authors performed surgery in 52 eyes of 30 patients in which prophylactic retinal treatment, clear lensectomy, and posterior chamber intraocular lens implantation were used to treat high myopia of 12 diopters (D) or greater. A total of 49 eyes of 28 patients were evaluated at the 4-year postoperative timeframe. Visual acuity, complications, and refractive stability were assessed. RESULTS: The incidence of retinal detachment through 4 years was 1.9%. No new macular complications were observed. Two patients had posterior vitreous detachment without clinical impact between 1 and 4 years after surgery. The incidence of neodymium:YAG (Nd:YAG) capsulotomy was 36.7%. The mean postoperative spherical equivalent was -0.92 D. Four patients had a myopic shift of 0.50 D to 1.00 D from the 1- to 4-year timeframe. Corrected visual acuity of 20/40 or better was achieved in 82% of eyes that had undergone Nd:YAG capsulotomy versus 56% of untreated eyes. Uncorrected visual acuity of 20/100 or better was achieved in 82% of eyes treated with the Nd:YAG laser versus 62% of untreated eyes. CONCLUSION: Visual acuity and refractive outcomes with clear lensectomy are favorable. Retinal detachment remains the major concern of this procedure. Continuous follow-up of these patients is necessary.

Adult↗
PubMed1997

[Keratoconus, changes in corneal topography and allergy. Study of 3 groups of patients].

PURPOSE: To study the relation between keratoconus and atopy based on allergic prick tests, and the association of infraclinical keratoconus with atopy compared to "normal eyes". Simultaneously corneal topographic modifications have been researched to patients presenting an ocular atopy versus normal patients. MATERIAL AND METHOD: A videokeratoscope has been used for the selection of 22 keratoconic patients, 17 infraclinical keratoconic subjects and 22 patients with no ocular abnormality. Incidence of allergic phenomenon was assessed with two tests (Prick test, lacrymal total IgE dose). The videokeratoscopy was also performed in the research of corneal modifications in a group of 45 patients with an ocular atopy. RESULTS: The results of allergologic tests (positives Prick tests) showed a statistical significant difference between the keratoconus group (63.6%) and respectively the infraclinical keratoconus group (23.5%) and the normal eyes group (22.7%). No videotopographic picture of keratoconus and infraclinical keratoconus has been noted in patients with ocular atopy. CONCLUSION: Keratoconus is related to allergy. In this study, no association of allergy with infraclinical keratoconus was found. Further more, no videotopographic changes was observed in ocular allergic cases.

Adolescent↗
PubMed1997

Ganciclovir ophthalmic gel (Virgan; 0.15%) in the treatment of herpes simplex keratitis.

PURPOSE: Ganciclovir is a broad-spectrum virustatic agent. Its efficacy and safety after ocular application have been demonstrated in studies of herpetic keratitis in rabbits. Two strengths of ganciclovir gel (0.05 and 0.15%) were compared with 3% acyclovir ointment in the treatment of superficial herpes simplex keratitis in humans. METHODS: Two multicenter randomized clinical trials were carried out in Africa (Trial 1) and Europe (Trial 2). Sixty-seven patients (Trial 1) and 37 patients (Trial 2) from herpetic ulceration were recruited. RESULTS: The results showed no statistically significant difference between the treatment groups, although the healing rates tended to be better in the group receiving 0.15% ganciclovir gel, with healing rates of 85% (Trial 1) and 83% (Trial 2) as compared with 72% (Trial 1) and 71% (Trial 2) in the group receiving acyclovir ointment. Local tolerance was found to be superior with the gel formulation of ganciclovir with fewer complaints of discomfort (stinging, burning) or blurred vision after application of the drug. Systemic absorption of the drug was low. No hematologic changes were detected. CONCLUSIONS: These findings support the efficacy of ganciclovir gel in the treatment of ulcerative herpes simplex keratitis and demonstrate its superior local tolerance when compared with acyclovir ointment.

Acyclovir↗