P Lozato

CHNO des Quinze-Vingts, Lutetia Parisorum, Île-de-France, France

Are you P Lozato?

Claim your profile

Publications (9)11.29 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: To study specimens obtained from epiretinal membrane (ERM) and macular hole surgery with confocal microscopy and to evaluate its advantages in understanding their pathophysiology. This retrospective study included 50 patients undergoing surgery for epiretinal membrane (40 patients) or idiopathic macular hole (10 patients). Infracyanine green was used in 45 cases. Immunohistological examination of the excised tissues was undertaken using confocal microscopy after labeling with antibodies to glial fibrillary acidic protein (GFAP) and vimentin. Confocal microscopic analysis of epiretinal membranes identified three types of tissues: 13 ERMs, which appeared thick and rich in cells, 20 internal limiting membranes (ILMs), which appeared thin, wrinkled and poor in cells, and seven composite tissues, where ERM and ILM were removed at the same time. The analysis of ten specimens obtained from macular hole surgery revealed nine ILMs and one composite tissue that were quite similar to those removed in epiretinal membrane surgery. In all, 27 specimens (10 ERMs, 12 ILMs and five composite tissues) contained GFAP-positive glial cells. The confocal microscope provided a fast, three-dimensional analysis of ERMs and ILMs. An immunohistological study identified cells that take part in the genesis of the membranes. Glial cells were found both in ERM and ILM specimens. Our findings suggest that Müller's cells may contribute to the pathogenesis of ERM and macular hole development.
    Journal Français d Ophtalmologie 02/2005; 28(1):19-29. · 0.44 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Purpose To study specimens obtained from epiretinal membrane (ERM) and macular hole surgery with confocal microscopy and to evaluate its advantages in understanding their pathophysiology. Material and methods This retrospective study included 50 patients undergoing surgery for epiretinal membrane (40 patients) or idiopathic macular hole (10 patients). Infracyanine green was used in 45 cases. Immunohistological examination of the excised tissues was undertaken using confocal microscopy after labeling with antibodies to glial fibrillary acidic protein (GFAP) and vimentin. Results Confocal microscopic analysis of epiretinal membranes identified three types of tissues: 13 ERMs, which appeared thick and rich in cells, 20 internal limiting membranes (ILMs), which appeared thin, wrinkled and poor in cells, and seven composite tissues, where ERM and ILM were removed at the same time. The analysis of ten specimens obtained from macular hole surgery revealed nine ILMs and one composite tissue that were quite similar to those removed in epiretinal membrane surgery. In all, 27 specimens (10 ERMs, 12 ILMs and five composite tissues) contained GFAP-positive glial cells. Conclusion The confocal microscope provided a fast, three-dimensional analysis of ERMs and ILMs. An immunohistological study identified cells that take part in the genesis of the membranes. Glial cells were found both in ERM and ILM specimens. Our findings suggest that Müller's cells may contribute to the pathogenesis of ERM and macular hole development.
    Journal Francais D Ophtalmologie - J FR OPHTALMOL. 01/2005; 28(1):19-29.
  • [Show abstract] [Hide abstract]
    ABSTRACT: The Authors report the case of a 50-Year-old man with myotonic dystrophy, who developed severe bilateral capsulorhexis contracture after uneventful cataract surgery. Phacoemulsification was performed in both eyes with implantation of intraocular lenses. The patient came to complain of decreased vision in both eyes (4/10 Parinaud 4). Visual acuity initially improved after surgery to 8/10 P2 in each eye. After 7 months for the right eye and 3 Months for the left eye, the patient presented with dramatically reduced vision, caused by a severe capsulorhexis contracture. Anterior capsulotomies with the Nd:YAG laser were performed in both eyes to treat this complication. It was sufficient on the left eye but the right eye required a surgical anterior capsulectomy to remove the IOL and the bag and put in an Artisan lens. Capsulorhexis contracture results from fibrous metaplasia of lens epithelial cells from the anterior capsule. Myotonic dystrophy appears to predispose to the development of severe capsulorhexis contracture after phacoemulsification.
    Journal Français d Ophtalmologie 06/2004; 27(5):479-83. · 0.44 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: IntroductionLes auteurs rapportent le cas d’un homme de 50 ans, atteint d’une dystrophie myotonique de Steinert, qui a développé un capsulophimosis sévère bilatéral après une chirurgie de la cataracte sans incident.ObservationLe patient a été opéré, par phacoémulsification et mise en place d’un implant souple en chambre postérieure, pour une baisse progressive de l’acuité visuelle. Dans les suites immédiates, le patient a récupéré, pour chaque œil, une acuité visuelle de 8/10e Parinaud 2. Dans les suites opératoires tardives (7 mois pour l’œil droit et 3 mois pour l’œil gauche), le patient a présenté à droite une luxation du sac et de l’implant de chambre postérieure alors qu’à gauche existait une rétraction sévère de la cristalloïde antérieure. Des capsulotomies au laser YAG ont été réalisées dans chaque œil.Alors qu’à gauche ce traitement était suffisant, à droite une intervention chirurgicale a été nécessaire pour restaurer une acuité visuelle chiffrable. Elle consista en l’ablation du sac et de l’implant de chambre postérieure, remplacé par un implant de chambre antérieure Cristallens « Artisan® ».DiscussionLa constriction du capsulorhexis résulte d’une métaplasie fibreuse des cellules épithéliales résiduelles de la capsule antérieure. Cette complication rare mais sévère impose le dépistage des personnes à risque et la réalisation de certaines manœuvres peropératoires sans que cela ne prévienne cette complication de manière certaine.Conclusion La dystrophie myotonique de Steinert semble prédisposer à la constriction sévère du capsulorhexis après chirurgie de la cataracte.IntroductionThe authors report the case of a 50-year-old man with myotonic dystrophy, who developed severe bilateral capsulorhexis contracture after uneventful cataract surgery.ObservationPhacoemulsification was performed in both eyes with implantation of intraocular lenses. The patient came to complain of decreased vision in both eyes (4/10 Parinaud 4). Visual acuity initially improved after surgery to 8/10 P2 in each eye. After 7 months for the right eye and 3 months for the left eye, the patient presented with dramatically reduced vision, caused by a severe capsulorhexis contracture. Anterior capsulotomies with the Nd:YAG laser were performed in both eyes to treat this complication. It was sufficient on the left eye but the right eye required a surgical anterior capsulectomy to remove the IOL and the bag and put in an Artisan® lens.DiscussionCapsulorhexis contracture results from fibrous metaplasia of lens epithelial cells from the anterior capsule. Myotonic dystrophy appears to predispose to the development of severe capsulorhexis contracture after phacoemulsification.
    Journal francais d'ophtalmologie 05/2004; 27(5):479-483. · 0.51 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: To analyze the relevance of a human conjunctival cell line in a study of conjunctival epithelium. We investigated and compared the effects of IFNgamma and TNFalpha in a primary culture of human conjunctiva and in a human conjunctival cell line. A primary-cultured human conjunctival epithelium and a human conjunctival cell line (Chang cells) were treated for 72 hr with 20, 200, 400 and 600 U ml(-1) IFNgamma or with 1100 and 11,000 U ml(-1) TNFalpha. Then, the expression of HLA DR, CD40, CD44, CD63, CD80, CD86, Fas receptor, E-cadherin, ICAM-1, MUC1, cytokeratins and vimentin were investigated by flow cytometry. Cell morphology was studied with phalloidin staining. Apoptosis was detected by flow cytometry with Annexin V and via cell cycle analysis. The primary culture of human conjunctival epithelium expressed cytokeratin K4, non-keratinized squamous epithelial marker. Chang cells presented a more dedifferentiated phenotype and were cytokeratin K4 negative. In primary-cultured cells, IFNgamma (600 U ml(-1)) induced only a low level of apoptosis and a significant upregulation of most tested proteins such as HLA DR, Fas, ICAM-1, CD40 and CD63. In the Chang cell line, IFNgamma induced a significant level of apoptosis at concentrations of 200, 400 and 600 U ml(-1). HLA DR and CD63 were induced at lower levels than in primary-cultured cells. Other proteins were modified in a similar manner after IFNgamma treatment in both systems. In the primary-cultured cells, TNFalpha induced an important upregulation of ICAM-1, Fas and CD40 whereas CD44 and CD63 were significantly decreased. Conversely, only a very weak alteration of CD63 and ICAM-1 was observed in the Chang cell line after TNFalpha treatment. A primary culture of a human conjunctival epithelium demonstrated well-defined epithelial features. TNFalpha and IFNgamma, two inflammatory cytokines, induced different effects in both cellular systems, in a primary-cultured conjunctival epithelium and a human conjunctival cell line. Inflammation-related molecules were highly upregulated in the primary culture and, to a lesser extent, in the Chang cell line. Thus, the Chang cell line differs in certain features from a primary culture of human conjunctival epithelium, a fact which emphasizes the complexity of interpretation of in vitro data and this should be taken into consideration in in vitro studies of human conjunctival epithelium.
    Experimental Eye Research 03/2004; 78(2):257-74. · 3.03 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: To evaluate the contribution of intravitreal infracyanine green to macular hole and epimacular membrane surgery. Twenty-five consecutive patients were operated on for macular hole (seven cases) or epiretinal membrane (18 cases) using intravitreal infracyanine. In most cases, 25mg of infracyanine powder was diluted in 5ml of solvent, then in 5ml of BSS and used within 1 hour. The solution was injected at the end of the vitrectomy and aspirated after 1-2 minutes. The internal limiting membrane was removed in both diseases. All specimens were studied using confocal microscopy or an immunocytochemical preparation. In cases of macular hole, the internal limiting membrane was bright green colored. Opening and peeling were greatly facilitated. In cases of epiretinal membrane, staining was variable: the most frequent aspect was an uncolored central area similar to a geographic map surrounded by a green stained zone. Sometimes the coloration appeared as sparse spots on the posterior pole. Occasionally the staining was homogeneous as in the macular hole cases. After the removal of the membrane, a second injection made it possible to check for the persistence of the internal limiting membrane and proceed to its ablation when necessary. A good correlation was found between surgical and histopathological aspects. Intravitreal infracyanine green is very helpful for the removal of internal limiting membrane in macular holes and epiretinal membrane surgery.
    Journal Français d Ophtalmologie 12/2002; 25(9):915-20. · 0.44 Impact Factor
  • P A Lozato, P J Pisella, C Baudouin
    [Show abstract] [Hide abstract]
    ABSTRACT: The preocular tear film (POTF) is composed of a deep aqueous-mucin phase that supports a thin superficial lipid phase. The tear lipid layer (TLL), although thin, stabilizes the POTF providing a 25% surface-tension decrease and a 90-95% aqueous evaporation reduction. TLL is formed from lipids secreted by tarsal meibomian glands and spread onto the ocular surface by blinking. The TLL itself is composed of two phases. A thin and deep polar phase, adjacent to the aqueous-mucin layer, has a surfactant role. A thicker and superficial nonpolar phase has antievaporative properties. At the same time, tear lipocalins help the TLL spread and stabilize the lipid-aqueous interface. For clinical examination, TLL is directly observed with the Tearscope. POTF stability and the evaporation rate depend on the lipid layer pattern. When chronic, POTF qualitative trouble (evaporative syndrome) due to a TLL anomaly, leads to secondary ocular surface impairment with increased tear instability and self-propagation of ocular dryness. Meibomian gland dysfunction (MGD) results from local pathology, dermatologic disease (ocular rosacea) or iatrogenic etiology. Cosmetic use is the other principal cause of TLL destabilization. Lid hygiene is the mainstay of MGD treatment. Systemic antibiotics (cyclins) can be associated in cases of severe symptoms. Topical treatment is useful if there is marginal lid inflammation or infection.
    Journal Français d Ophtalmologie 07/2001; 24(6):643-58. · 0.44 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: To investigate by flow cytometry and impression cytology (IC) specimens the inflammatory status of the conjunctival epithelium and goblet cell density in two series of patients with rosacea and dry eye syndrome compared with a population of healthy subjects. Nonrandomized, prospective, comparative case series. Twenty-six eyes of 13 patients with rosacea, 26 eyes of 13 patients with dry eye syndrome, and 24 eyes of 12 control subjects were included in this study. IC specimens were collected after clinical examination of the ocular surface and analyzed by flow cytometry, using antibodies directed to human lymphocyte antigen-DR (HLA-DR), intercellular adhesion molecule-1 (ICAM-1) (CD 54), and the peptidic core of the conjunctival mucin (M1/MUC5AC). The percentage of positive cells was calculated and levels of fluorescence expression quantified and compared with those obtained in a series of 12 healthy subjects. Tear break-up time (TBUT), Schirmer test, fluorescein and lissamin green stainings, and IC were realized in this study. A significant increase of HLA-DR and ICAM-1 expressions by epithelial cells was consistently found in the two pathologic groups compared with levels calculated in normal eyes. The two markers were well correlated with each other and inversely with TBUT and Schirmer test. The percentage of goblet cells was significantly decreased in rosacea patients and in dry eye patients compared with the normal group with a significant negative correlation with both HLA DR and ICAM-1 markers. Ocular rosacea and keratoconjunctivitis sicca were associated with severe ocular surface changes, such as an overexpression of inflammatory markers and a significant decrease in the number of goblet cells.
    Ophthalmology 11/2000; 107(10):1841-9. · 5.56 Impact Factor
  • Journal Français d Ophtalmologie 06/1999; 22(4):475-80. · 0.44 Impact Factor

Publication Stats

128 Citations
11.29 Total Impact Points

Institutions

  • 2002
    • CHNO des Quinze-Vingts
      Lutetia Parisorum, Île-de-France, France
  • 2000
    • Clinique Ambroise Paré
      Tolosa de Llenguadoc, Midi-Pyrénées, France