Biomedical subjects
Publications and source records attributed to G Renard.
We report a French family suffering from an Avellino corneal dystrophy diagnosed by using clinical, histological, ultrastructural and genetics findings. Our results indicate that direct corneal examination and routine histological examinations must always be associated with an assay for BIGH3 gene mutations to establish a modern and unambiguous diagnosis of a corneal dystrophy.
PURPOSE: to evaluate the efficacy and the safety of low dose intraocular tissue plasminogen activator (rt-PA) in the treatment of traumatic hyphema and postoperative fibrinous membrane. METHODS: Six microg to 10 microg of rt-PA was injected into the anterior chamber to treat severe fibrinous postoperative membranes and total traumatic hyphemae. RESULTS: Thirteen eyes of 13 patients were treated. Four cases of traumatic hyphema and 9 cases of fibrinous membranes were included. Complete fibrinolysis within 24 hours was observed in 4 cases (30.8%). A partial success was noted in 7 eyes (53.8%). No beneficial effect was observed in two cases of traumatic hyphema associated with intravitreal hemorrhage after penetrating trauma. No side effect attributable to rt-PA occurred. CONCLUSION: Low dose intraocular rt-PA appears to be safe and effective in the treatment of postoperative fibrinous membrane and endocular hemorrhage limited to the anterior chamber.
An 18-year-old female patient developed a mass in the superomedial angle of her left orbit. After evaluation, this tumor was surgically removed. A dysembryoplastic cyst lined with conjunctival epithelium was diagnosed by light microscopic examination. Clinical and pathological data are detailed. The characteristics of dysembryoplastic orbital cysts are reviewed.
An amorphous and transparent form of Teflon is proposed as a coating of polymethylmethacrylate (PMMA) intraocular lenses (IOLs), rendering them highly hydrophobic. We used an organ culture method to evaluate cell adhesion, proliferation, and migration on Teflon-coated IOLs. Corneal explants from 14-day-old chicken embryos were placed on a semisolid culture medium and covered with uncoated PMMA (n = 36) and Teflon-coated PMMA (n = 36) IOLs and two controls, Thermanox (n = 84) and latex (n = 36). After incubation (7 days at 37 degrees C), a digital imaging system was used to measure the areas of the cell migration layers on the materials. The cells were then removed with tripsin-ethylenediaminetetraacetic acid and the cells detached at times up to 75 min were counted (Coulter(R) Multisizer System). The values were used to construct a cell disconnecting curve for each material. The areas of cell migration layers on uncoated and Teflon-coated IOLs were significantly different (p <.05). Cell disconnecting curves demonstrated that cells adhered less strongly to Teflon-coated IOLs than to the other materials. This organ culture method demonstrated that the coating of PMMA IOLs with Teflon AF(R) is correlated with antiadhesive and antiproliferative properties.
To investigate the effects of focal implantation of expanded polytetrafluoroethylene (e-PTFE) episcleral implants (i.e., explants or exoplants) on surrounding ocular tissues, an experimental and histopathological study was performed. Twenty-seven Fauve de Bourgogne rabbits eyes were implanted for a period of 3-11 months with oval-shaped e-PTFE episcleral implants. A newly formed capsule constantly encased the implants. Affected by the only two severe complications observed, 2 eyes had an endocapsular acute inflammation and could not be included in the study. Finally, 25 eyes were studied histopathologically. Neither intrusion nor extrusion of episcleral implants was observed. Other changes were related to implant characteristics. The inner surface of the capsule was often covered with numerous giant cells attesting to a foreign-body granuloma developed against the irregular outline of the episcleral implants. The porosity of the material was closely related to its surface irregularity, and also allowed its colonization by a fibrovascular and inflammatory tissue mainly in its peripheral layers. Under episcleral implants, sclera was both thinned and invaginated. Expanded PTFE hydrophobia was the other factor that might have suscitated granuloma. These microscopic changes are in contrast with an overall good apparent experimental tolerance to the material. However, additional studies on the long term behavior of this material would be helpful.
Polymethylmethacrylate (PMMA) intraocular lenses (IOLs) were coated with Teflon AF, an amorphous, transparent Teflon, to render them highly hydrophobic. Teflon-coated PMMA IOLs were immersed in culture medium for 30 days at 37 degrees C. Four concentrations of the IOL leachables, 2 concentrations of a toxic control (phenol), and complete liquid culture medium (nontoxic control) were incubated for 24 h in a 96-well plate containing confluent L-929 fibroblasts. The cytotoxic effect of each solution on the fibroblasts was quantitatively assessed by measuring the uptake of neutral red by the viable cells. After the extraction of the neutral red using 1% acetic acid-50% ethanol, the optical densities were measured with a microplate reader at 550 nm. Scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) were used to analyze the surfaces of the IOLs. Only the optical densities in the wells containing fibroblasts that had been in contact with the phenol solutions were significantly lower than those in the wells incubated with the nontoxic control solution (p < 0.01). There were no signs of surface alteration by SEM, apart from some crystals on the IOLs. The crystals were composed of Na and Cl, as demonstrated by XPS. Aqueous extractables from the Teflon-coated IOLs produced no cytotoxic effects in the neutral red assay used.
Corneal transparency depends on the precise organization of the stromal extracellular matrix. The morphology of the extracellular matrix of the embryonic and adult avian secondary posterior cornea was studied in glutaraldehyde-fixed, quick-frozen, deep-etched replicas with the electron microscope. Although the collagen fibrils changed from a loose network to a more ordered parallel lamellar arrangement during development, their mean diameter remained constant between 30.3 and 31.2 nm. Besides collagen fibrils, other extracellular matrix components were observed: (i) straight or Y-shaped cross-bridging interfibrillar 8-10 nm filaments with 18-22 nm globules; (ii) relatively loose networks of 10-20 nm beaded filaments, with a mean periodicity of 107 nm, often running perpendicular to the collagen fibrils and adhering to the plasma membrane of stromal cells at early developmental stages; (iii) straight or curved 6-12 nm strands forming sheets within the stromal matrix that progressively disappeared, whereas similar structures persisted at the Descemet's membrane-stroma interface; (iv) dense networks of filaments with 6-8 nm filaments, sometimes polygonally arranged, and a substructure of 2-3 nm filaments with globular domains, which progressively disappeared with maturation but remained at the Descemet's membrane-stroma interface; (v) polygonal networks of 9-10 nm filaments with globular domains adherent to the surface of cell plasma membranes at early developmental stages. The temporal expression of deep-etched supramolecular structural assemblies is compatible with that of the so-called 'interstitial basement membrane components' previously described. The quick-freeze and deep-etching method can reveal important aspects of the in situ organization of the corneal extracellular matrix.
OBJECTIVE: To use confocal microscopy to demonstrate the similarity among three autosomal-dominant corneal dystrophies and the diversity of the deposit patterns within a single dystrophy. DESIGN: A prospective, comparative case series. PARTICIPANTS: Twenty patients (40 eyes) from 10 families suffering from Bowman or stromal dystrophy agreed to take part: 3 with Reis-Bückler dystrophy, 12 with granular dystrophy, and 5 with lattice type-I dystrophy. Of these, nine had recurrence in their grafts or after phototherapeutic keratectomy before the confocal examination. The confocal images of affected corneas were compared with those of ten normal control eyes (ten subjects). INTERVENTION: All patients were examined by slit-lamp biomicroscopy. Confocal microscopy was performed with Achroplan 40x/numeric aperture (NA) = 0.75 and 63x/NA = 0.9 water immersion objectives. Image analysis was used to identify the corneal epithelial and stromal deposits correlated with each disorder. MAIN OUTCOMES MEASURES: Selected images of the corneal layers were evaluated qualitatively for the size, shape, light scattering, and reflection of the deposits. RESULTS: Slit-lamp biomicroscopy showed stromal involvement in all affected eyes. Confocal microscopy identified epithelial deposits in 30% of the eyes and stromal deposits in all eyes. The deposits within the epithelium were revealed more clearly with the 63x/NA = 0.9 objective (higher numeric aperture). Some of the confocal findings near the Bowman layer were common for all three dystrophies. Normal control eyes showed no epithelial or stromal deposits, either by biomicroscopy or confocal microscopy. CONCLUSIONS: Confocal microscopy provides an in vivo evaluation of the deposits in the cornea, with a higher resolution than biomicroscopy. The confocal findings common to the three dystrophies may agree with previous hypotheses of the same genetic origin. It may be a useful adjunct to slit-lamp biomicroscopy, particularly when histopathologic studies cannot be performed.
PURPOSE: To assess the degree of pseudoaccommodation amplitude correlated with shifts along the anteroposterior axis of the BioComFold foldable intraocular lens (IOL). SETTING: Department of Ophthalmology, Hôtel-Dieu Hospital, Paris, France. METHODS: This prospective study comprised 30 eyes of 30 patients operated on consecutively for cataract by phacoemulsification and in-the-bag implantation of a BioComFold (15 patients) or a foldable control (15 patients) IOL. The BioComFold IOL has a peripheral bulging ring that pushes the optic forward during the effort to accommodate, creating a zoom effect. Pseudoaccommodation amplitude was evaluated using the blurring of controlled vision by adding spheres, with the best correction for distance vision in place. Pupil diameter was measured with a Goldmann campimeter under constant illumination. Anterior chamber depth was determined by A-scan (Paxial, Biophysic Medical) 30 minutes after cyclopentolate 1% was instilled and again 30 minutes after pilocarpine 2% was instilled. RESULTS: The difference in pseudoaccommodation amplitude and pupil diameter between the 2 groups was not statistically significant (P = .6737 and P = .4014, respectively). The IOL's forward shifts from maximal ciliary relaxation to maximal ciliary contraction were significantly greater in the BioComFold group (P = .0215). CONCLUSION: The design of the BioComFold IOL allowed greater forward optic shifts along the anteroposterior axis during the effort to accommodate. Nevertheless, this shift was not correlated with a significantly greater pseudoaccommodation amplitude.
This study was conducted to determine whether indirect grid laser therapy is effective in reducing focal diabetic macular edema characterised by focal leaks and hard exsudates involving the para-foveal area (less than 300 microns from the center of the fovea). Since focal coagulation of microaneurysms in such a critical location can be deleterious, indirect grid pattern laser treatment may be used in such cases.
PURPOSE: To investigate scleral and episcleral histological alterations induced by encircling explants used in scleral buckling procedures. METHODS: We performed a histopathological study of 20 enucleated eyes after failure of retinal detachment surgery including encircling scleral buckle. RESULTS: Nonabsorbable materials were encapsulated and often gave rise to a limited scleral invagination. The inner capsular surface was regular in 10 silicone explants, it was partially covered with hydrogel fragments and a granulomatous foreign body giant cell reaction in 8 hydrogel explants. One Arruga thread was encased in fibrosis and a catgut circle showed no encapsulation. Other changes were mostly related to the long-standing retinal detachment: peripheral anterior synechiae, anterior uveal effusion, persistent retinal detachment, retinal gliosis, retinal atrophy, retinal breaks, and silicone oil droplets. CONCLUSION: All nonabsorbable explants underwent encapsulation and prompted scleral invagination. A granulomatous reaction accompanied hydrogel fragmentation. The long term fragmentation impact on implanted eyes remains unknown.
PURPOSE: To analyze histologic changes induced by encircling elements, rabbit eyes were implanted with two different biomaterials. MATERIALS AND METHODS: Thirty-seven rabbit eyes (37 rabbits) were implanted with encircling oval episcleral elements. Two materials were used: silicone sponge and hydrogel. The animals were killed and their eyes collected for histopathology. Of 37 eyes, 26 that were implanted for 111 to 455 days were selected for the study. RESULTS: In 26 eyes, scleral buckling was visible. Scleral examination showed a regular erosion under the buckle, mainly with silicone. All explants were surrounded by a fibrous capsule, which was smooth and regular with silicone. With hydrogel, fragmentation was observed with a giant cell reaction. Capsule thickness increased, mainly with hydrogel. CONCLUSION: Fragmentation affected segmental or circumferential hydrogel explants. As in silicone explants, the capsule surface was normal when the hydrogel surface was respected. The fragmentation mechanism remains unclear.
Most conjunctival nevi are found during the two first decades of life. Beyond this period, the diagnosis must be assessed by histopathology. We report the case of a conjunctival nevus recently discovered in a 33-year-old patient who, additionally, was previously treated for herpetic disciform keratitis. The corneal scar decreased vision. A corneal graft and nevus excision were performed simultaneously. Histopathologic study confirmed the diagnosis of nevus and disclosed the corneal scar changes induced by herpes.
PURPOSE: This study was designed to investigate the therapeutic potential of phototherapeutic keratectomy (PTK) for the treatment of corneal granular dystrophy. PATIENTS AND METHODS: PTK was performed with the Excimed UV 200, (Summit Technology, Inc) on a series of 27 eyes of 22 patients with corneal granular dystrophy. Mean patients' age was 34.6 years. The mean follow-up period was 31 months (ranged from 6 to 52 months). The changes in best corrected visual acuity and spherical equivalent were evaluated at 6, 12, 18 and 24 months. RESULTS: All of patients achieved visual improvement. Mean preoperative best corrected visual acuity (BCVA) was 20/100 and mean postoperative BCVA was 20/30 at one year. The mean hyperopic shift caused by tissue ablation was +/- 2.8 D after one year. CONCLUSION: Corneal grafting was the standard treatment for visually disabling granular dystrophy, but PTK has significant advantages over this procedure and must now be the standard method of managing corneal granular dystrophy when intervention is required.
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We report the case of a 33-year-old HIV-seropositive male who had a large cell Epstein-Barr virus-associated non-Hodgkin's orbital lymphoma. A thorough medical examination enabled us to find on thoracic CT-scan a mediastinal lymph node involvement as large as 18 cm in diameter. The regression of the tumor was dramatic under chemotherapy with complete disappearance of the tumor and no recurrence was found after more than 21 months follow-up. We discuss the differential diagnosis with orbital infection.
A clinico-pathologic case of a black hidrocystoma of the left eyelid margin is reported in a 45-year-old female patient. Clinically, a black nodule was disclosed after eversion of the superior left lid. A surgical full thickness eyelid focal resection was performed to remove the cyst. Histopathology found a cyst covered with an epithelium with a double layer of cells and filled with a brownish granular content, typical of a black hidrocystoma.