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Purpose To assess the outcome of patients with ocular cicatricial pemphigoid (OCP) treated with sulfasalazine as an alternative to dapsone. Design Retrospective noncomparative case series. Participants Nine patients with biopsy-proven OCP and previous dapsone-related adverse effects (hemolysis and gastrointestinal disturbances) treated with oral sulfasalazine. Methods Clinical data were abstracted from patients' medical records. Main outcome measures Patients' symptoms, ocular inflammation, conjunctival scarring, complete blood cell count (including reticulocyte count). Results At the initiation of sulfasalazine therapy, ocular inflammation was controlled in all patients but one. Mean follow-up was 12 months (range, 2–35 months). Median oral sulfasalazine dosage was 3 g (range, 1–4 g). The disease remained controlled with sulfasalazine alone in four patients (45%). Two patients (22%) required adjunctive oral cyclophosphamide. Adverse effects necessitating drug withdrawal occurred in three patients (33%): hemolysis in two and gastrointestinal disturbances in one. Conclusions Sulfasalazine may be useful in OCP patients with previous dapsone-related adverse effects.

Designed to avoid postoperative hypotony that often occurs after trabeculectomy and to maintain long lasting filtration, the MESH is a thin porous expended polytetrafluoroethylene (ePTFE) implant that mimics the physiological meshwork. The aim of this study is to assess the tolerance, biocompatibility and effectiveness of this device during 6 months in the rabbit.We used an ePTFE with about 5 microns pore size (Zytex). The head of the implant is 3,0 mm wide and 1,5 mm long and fits in the anterior chamber. The tail is 2,0 mm wide and 3,0 mm long and fits in the subconjunctival space. The MESH is 250 microns thick. 24 Dutch pigmented rabbits were selected because their dark pigmented iris contrasts with the ePTFE implant giving a better visualization. All the animals were cared for in accordance with ARVO resolutions. Surgery was performed on the right eye by the same surgeon (P.H.), the left eye serving as control for IOP measurements. The animals were distributed in 3 groups: one with MESH alone (MESH), one with MESH and Mitomycin C (MMC), one with MESH and 5-FU (5-FU). Follow-up was performed every week (W) during 6 months including IOP measurement, slit lamp observation, photography and bleb assessment. Histological study was done at POD 0, 15, 30, 90 and 180 one eye in each group. Student t test and alternate Welch t test were used for statistics.Filtering bleb: no bleb was visible before W3. A bleb was found between W3 and W6, decreasing between W6 and W9 with no more change after W10. The MESH implant: no change appears in the color of the MESH during the study. Some iris pigments or synechiae were seen in some cases. No extrusion occurred. Intraocular pressure: IOP was lower than in the control eye. The statistical analysis showed a significant lower pressure for the MESH alone at W5 (p = 0.0069), for the 5-FU group at W1 (p = 0.0326), W2 (p = 0.0488), W4 (p = 0.0312). With Mitomycine C we found very significant results at W1 (p = 0.0073), W2 (p = 0.0136), W4 (p = 0.0497), W9 and W11 (p = 0.0174). After W12 the groups were joined and IOP was significantly decreased at W17 (p = 0.0376) and W23 (p = 0.0462). Histology confirmed the correct position of the MESH, its biocompatibility and its ability to drain aqueous humor even if there is colonization of the pores by fibroblast-like cells.The present study has shown that the filtering bleb appeared after 3 weeks without major hypotony. The material was integrated only in the intrascleral tunnel and was stable. After 6 months the Mesh was well tolerated. The new concept has a simple surgical technique, less invasive than trabeculectomy and required less surgical time. This technique reduced IOP and produced long survival blebs in rabbits. This device appears suitable for the surgical treatment of open angle glaucoma.

GIAK is a surgical technique developed for the correction of myopia. We evaluated the biocompatibility of a gamma-ray crosslinked poly(ethylene oxide) gel in two critical situations.In 3 rabbits, a 5 mm inner diameter annular channel of 1 mm width was delaminated at 80% corneal depth and a sterile gamma-ray crosslinked polyethylene oxide gel was injected in the channel. In cornea 1 (control), the annulus was centered on the corneal apex and the channel was fully filled with gel. In cornea 2, the delamination was purposely decentered and the channel was approximately 1 mm from the limbus at its closest point. In cornea 3, the centered channel was purposely partially filled. After a 6 month follow-up, the rabbits were sacrificed for histology.Histopathology showed the oval channel walls to be irregular and a slight thinning of the epithelium located above the implant but no abnormalities in the stromal thickness. No mononuclear, polynuclear cells or other signs of encapsulation or rejection were found around the polymer in any of the animals. In cornea 3, fibroblasts were found on the lateral sides of the hydrogel globules. No limbal neovascularization was observed over the 6 month period in any of the animals.The injected PEO gel followed intimately the delaminated stromal channel and was well tolerated in the cornea. The fibroblastic reaction found in partially filled channels is caused by the normal wound healing process and not by the hydrogel chemical properties.

A case of non familial primary amyloidosis of the vitreous body with bilateral involvement was reported. Pars plana vitrectomy improved visual acuity in both eyes and allowed histological confirmation on light microscopy and ultrastructural examination.

The authors report the case of a 37 year-old male who presented with type I Hurler-Scheie (H-S) mucopolysaccharidosis revealed by ocular complications including bilateral corneal opacification and glaucoma. These complications are identical to those seen in Scheie's mucopolysaccharidosis. The patient underwent a trabeculectomy and a penetrating keratoplasty in both eyes. The corneal storage material was shown on the histological and ultrastructural examination of the buttons. These ocular complications result from excessive tissular storage of acid mucopolysaccharides due to an enzymatic alpha-L-iduronidase deficiency which was proved in our patient. H-S mucopolysaccharidosis is also characterized by dysmorphia and altered intellectual functions like in Hurler's disease in which the prognosis is however. The characteristics of the disease are discussed as well as the different therapeutical strategies which rely on leucocyte injections, skin fibroblast or bone marrow transplantation.

Introduction Environ 3 500 greffes de cornees ont ete realisees en 2007 en France. Les cornees prelevees pour etre greffees sont soumises a un protocole precis comprenant des tests biologiques, un comptage de nombre de cellules endotheliales et une evaluation de la transparence. En ce qui concerne ce dernier point, il n’existepas en tant que telle de methode permettant de quantifier la transparence, seulement l’appreciation subjective de la transparence par une personne habilitee. L’obtention de la qualite objective de la cornee serait un atout considerable. Les mecanismes impliques dans la transparence constituent un sujet de recherche. Objectifs et Methodes Pour quantifier cette transparence, deux types de montages ont ete realises. Le premier permet d’acquerir des images d’une mire a travers la cornee, ces images seront ensuite traitees numeriquement afin de determiner la fonction de transfert de modulation (MTF) du tissu considere. Le deuxieme type de montage permet la mesure des spectres de transmissions totale et directe a travers la cornee afin de quantifier la diffusion du tissu et la section efficace de diffusion, en fonction de la longueur d’onde du faisceau, sur une large gamme spectrale. On peut ainsi comparer la diffusion mesuree et la diffusion prevue par une modelisation du tissu. Discussion La fonction de transfert de modulation du tissu permet d’avoir acces a un parametre quantitatif pour la qualite de la cornee. On constate que la signature spectrale de la cornee possede deux composantes : l’absorption d’une part, le spectre presentant alors les bandes d’absorption de l’eau, et la diffusion d’autre part, qui diminue lorsque la longueur d’onde augmente. Conclusion Pour chaque cornee, nous disposerons alors de donnees quantitatives, issues du traitement des images et de l’analyse des spectres. On pourra ainsi dire de facon objective si un greffon est apte a etre greffe.

But Definir la nature de l’opacification de l’implant acrylique hydrophile et sa prise en charge chirurgicale. Materiels et Methodes Nous rapportons les cas de deux patients operes de decollement de retine par vitrectomie, endolaser et gaz avec utilisation de perfluorocarbone liquide en per-operatoire qui ont ete operes dans les suites d’une cataracte par phacoemulsification avec mise en place d’un implant acrylique hydrophile dans le sac. Apres plusieurs mois, l’acuite visuelle des deux patients a baisse progressivement (inferieur a 2/10 P10) en rapport avec une opacification de la face anterieure de l’implant. Leur prise en charge a necessite une explantation et la mise en place d’un implant clippe a la face posterieure de l’iris. Discussion L’acuite visuelle des deux patients est remontee en post-operatoire (superieur a 6/10 P3). Il n’y a pas eu de complication per-operatoire ou post-operatoire. L’analyse en microscopie des implants a permis de confirmer la presence de materiel inerte translucide fixe a la face anterieure de l’implant et d’eliminer une origine calcique comme decrit dans la litterature. La nature de ces depots reste indeterminee mais une interaction entre le perfluorocarbone liquide et l’implant acrylique hydrophile est hautement probable. Conclusion L’opacification des implants acryliques hydrophiles est une complication rare mais grave dont la physiopathologie reste mal connue. Le traitement necessite une explantation qui emporte generalement le sac capsulaire.

Objectif Evaluer le Laser Femtoseconde comme alternative au laser Excimer dans les PKT. Materiels et Methodes 5 patients ont ete traites par PKT au Laser Femtoseconde FS 60. Ils presentaient tous une cataracte avec une keratopathie en bandelette (n = 4) et une opacite post-traumatique (n = 1). La cornee a ete operee avant chirurgie du cristallin. Le bilan pre-operatoire incluait une mesure subjective de l’AV et une photo de la cornee. La profondeur de la photoablation etait determinee par l’OCT-Visante. Une etude histologique du fantome de la decoupe a ete pratiquee afin d’evaluer la congruence et la regularite de l’epaisseur et de la surface d’ablation. Les decoupes ont ete faites en mode Flap/Raster en double passage avec une energie maximale (2.6-2.85 μJ) sur un diametre de 9 mm et une profondeur de 75 μm a 95 μm. Une lentille therapeutique etait posee systematiquement. Resultats Dans tous les cas, l’ablation du tissu a pu etre effectuee a la pince. A 3 mois, aucune recidive de l’opacite n’a ete diagnostiquee et la transparence corneenne a ete amelioree avec un axe optique bien degage. Les decoupes anatomo-pathologiques ont confirme la congruence et l’homogeneite de l’ablation estimee a l’OCT-Visante. Aucun retard de re-epithelisation n’a ete observe. Discussion Les PKT au laser Excimer dans les opacites corneennes profondes se heurtent aux difficultes de choix de la profondeur de l’ablation et de son diametre. Ce choix est fixe par l’analyse faite a l’OCT-Visante. Avec le laser Femtoseconde, il est indispensable d’utiliser des energies maximales (2.6 μJ-2.85μJ) en technique de double passage pour obtenir une decoupe efficace. Il est necessaire d’ajuster de 15 μm la profondeur du capot, mesuree a l’OCT-Visante pour s’assurer de l’ablation de la totalite de l’opacite. Conclusion L’OCT-Visante est un outil efficace et indispensable pour mesurer l’epaisseur a ablater dans les PKT au Laser FS. Les parametres de tir du laser Femtoseconde pour le Lasik (0.8 μJ-1.2μJ) sont a reajuster pour obtenir une meilleure decoupe en cornee opaque.

But Etude de la preparation de greffons endotheliaux par laser Femtoseconde et determination des parametres de tirs optimaux. Objectifs et Methodes Les cornees sont montees sur chambre artificielle. Les decoupes posterieures endotheliales sont realisees au laser femtoseconde intralase utilisant le module greffe dans sa version upgradee integrant l’option greffe lamellaire posterieure. Les decoupes sont realisees a des profondeurs progressives (300, 600 et 800 microns) apres controle pachymetrique des cornees. Les procedures sont realisees avec un passage unique ou deux passages pour chaque profondeur. La decoupe de la partie endotheliale est evaluee en microscopie optique et electronique. Resultats La decoupe endotheliale est possible sur cornee œdemateuse de plus de 1 000 microns jusqu’a 800 microns de profondeur. L’obtention d’une decoupe reguliere necessite la technique du double passage. Le passage unique classique ne permet pas une separation aisee de la structure posterieure. Il n’existe pas d’atteinte endotheliale lorsque la bulle de cavitation affleure la region endotheliale. Aucun effet thermique n’est observe lors du passage double en dehors d’une discrete densification du tissu a l’interface. Une cartographie pachymetrique est necessaire pour permettre l’obtention d’une congruence des decoupes. Discussion Le laser femtoseconde est moins efficient dans les structures corneennes profondes et en cas d’œdeme ou d’opacite. Les energies doivent etre maximales (2.82 micro joules) et seul un passage double permet une decoupe reguliere et reproductible dans la version des lasers actuellement disponibles. Conclusion Cette etape est indispensable avant la realisation des premieres greffes endotheliales par laser femtoseconde en clinique humaine programmee pour janvier 2008.

Objectif Evaluation des 7 premieres keratoplasties transfixiantes en Z realisees au laser femtoseconde sur œdeme du pseudophake. Materiels et Methodes Les patients ont ete operes avec un laser femtoseconde de type Intralase integrant la fonction greffe. Les auteurs ont utilise la technique du double passage pour la preparation du greffon (sur chambre artificielle) et le traitement des patients (anesthesie topique). Pour chaque patient un gap de 50 microns a ete programme pour permettre une ouverture du globe oculaire dans un second temps sous anesthesie generale. Une greffe en Z a ete realisee pour chaque patient avec une energie comprise entre 2.52 et 2.82 microjoules. Les reliquats des decoupes des yeux de banque et les cornees pathologiques ont ete systematiquement evalues par microscopie optique et electronique. Resultats La duree de chaque trepanation est en moyenne de 227 secondes (211–239) en utilisant la technique du double passage (greffon ou receveur). Chaque procedure a ete realisee sans incident intercurrent. Les decoupes ont pu etre realisees facilement sans l’utilisation d’une decoupe manuelle complementaire. Aucun seidel post operatoire n’a ete observe. La congruence greffon — receveur est optimale. L’ablation des fils a 6 mois est envisagable sans entrainer de decalage secondaire du greffon. L’astigmatisme post operatoire est en moyenne de 3.7 dioptries (1.5 D-7 D). Les decoupes ne montrent pas d’effet thermique en microscopie, la decoupe est unique sans double decoupe et sans modification ultrastructurale en dehors d’une densification legere de l’interface. Discussion Le laser femtoseconde presente des limitations d’efficacite en cas de cornee opaque. Elles peuvent etre attenuees par l’augmentation des energies en moyenne 2.3 fois plus elevees que celles utilisees pour une procedure de type LASIK. Nous conseillons la technique du double passage pour obtenir des decoupes reproductibles et eviter des decoupes incompletes ou insuffisantes en cas de traitement de cornee opaque et epaisse. Conclusion Le laser femtoseconde peut etre utilise avec succes pour le traitement de cornee opaque par keratoplastie.

Introduction L’injection intra-vitreenne de triamcinolone acetonide est realisee en pratique courante pour traiter des affections oculaires d’origine diverses. Des travaux pre cliniques ont montre que la triamcinolone acetonide exercait in vitro et in vivo une toxicite retinienne, alors que d’autres etudes n’ont pas mis en evidence de toxicite fonctionnelle. Les mecanismes d’une eventuelle toxicite restent imparfaitement compris. But Le but de ce travail a ete d’analyser de facon systematique les effets de differents glucocorticoides in vitro et in vivo sur differents parametres de la survie cellulaire et les mecanismes de toxicite. Materiel et methodes Nous avons injecte 1 microl (40 microg) de Kenacort retard dans le vitre de rat Lewis et avons analyse les yeux 24 heures et 8 jours plus tard en ultra-structure et par detection de l’apoptose par l’activation des caspases, du cytochrome C, du facteur AIF, et par la methode TUNEL. Nous avons egalement recherche la presence d’autophagie. In vitro, sur des cultures de lignees cellules d’epithelium pigmentaire de la retine humaine et sur des cultures primaires d’epithelium pigmentaire de la retine et de cellules gliales de Muller de rat (RMG), nous avons teste les effets a differentes doses de triamcinolone acetonide et d’autres glucocorticoides et avons egalement recherche les differents marqueurs d’apoptose, de necrose et d’autres formes atypiques de mort cellulaire. Nous avons evalue les effets d’excipient du Kenacort et des cristaux de triamcinolone acetonide sur la toxicite. Resultats L’analyse ultra structurale de la retine apres injection intra-vitreenne met en evidence une souffrance de l’epithelium pigmentaire de la retine et des cellules gliales mais pas d’alteration des photorecepteurs. Aucun des marqueurs d’apoptose n’est positif. In vitro, la triamcinolone acetonide entraine une reduction de la survie des cellules gliales plus importante que celle observee sur les cellules d’epithelium pigmentaire de la retine. Les formes de glucocorticoides les plus hydrophobes sont les plus toxiques et l’excipient par lui-meme n’entraine pas de mort cellulaire. La toxicite observee met en jeu des mecanismes de mort atypique par paraptose, comme cela a ete observe dans certains neurones. Discussion Le type de mort que nous decrivons ici n’est pas detecte par les methodes de toxicologie classique, expliquant que d’autres etudes ont observe des signes de toxicite sans pouvoir les caracteriser. Conclusion Une toxicite directe de la triamcinolone acetonide est observee sur la retine par un mecanisme non classique de mort cellulaire. D’autres glucocorticoides sont mieux toleres et pourraient efficacement etre utilises en limitant les risques qui se cumulent avec la repetition des injections.

But Les auteurs presentent les resultats d’etudes preliminaires histologiques et ultra-structurales des effets secondaires du laser femtoseconde sur des greffons. Materiels et Methodes Un laser clinique et un dispositif experimental avec caracteristiques techniques comparables aux systemes commerciaux sont utilises. Les cornees, a but scientifique, sont delivrees par la Banque Francaise des Yeux. Des incisions dans le plan lamellaire et dans le plan posterieur-anterieur sont effectuees a differentes energies. Les echantillons sont analyses en microscopie optique et en microscopie electronique a transmission. Resultats L’observation histologique et ultra-structurale du tissu montre que des particules micrometriques de verre sont observees dans les cornees, lors des decoupes transfixiantes. Dans des cornees pathologiques, les decoupes transfixiantes a energie constante ne sont pas uniformes dans toute l’epaisseur. Des structures periodiques apparaissent en profondeur de la cornee lors des decoupes lamellaires. Discussion Les particules micrometriques proviennent d’ejectas issus de l’usinage laser dans les lentilles d’aplanation. Les decoupes non uniformes et la structure periodique seraient dues a des phenomenes d’interaction non lineaires du laser avec le tissu pathologique. Conclusion Il apparait que les protocoles de decoupe devront etre adaptes pour eviter la focalisation dans la lentille d’aplanation. L’optimisation de l’energie de decoupe permet de limiter les effets secondaires.

But Nous avons demontre l’efficacite de WST11 pour occlure selectivement les neovaisseaux choroidiens (NVC) chez le rat, sans dommages collateraux. Le but de ce travail a ete de definir les parametres optimaux de la phototherapie dynamique (PDT)-WST11 chez le singe avant une evaluation clinique. Materiels et Methodes Des NVC ont ete induits dans 12 yeux de macaques cynomologus au laser argon (50 μm, 575 MW, 0.1 s). Quatorze jours apres, une angiographie en fluorescence (AF) et ICG confirmait les NVC autour de 30 % des points d’impact laser. Deux dosages de WST11 ont ete testes (2.5 et 5 mg/Kg). L’illumination utilisait un laser 753 nm et des intensites de 25 J/cm2, 50 J/cm2 or 100 J/cm2 (600 W/cm) avec des temps d’illumination (TI) de 1, 5 ou 10 minutes Les angiographies etaient realisees immediatement apres traitement (aigue), a 2, 8, 15, 21 et 28 jours. Avec les parametres d’occlusion selectifs definis, 2 singes etaient sacrifies a J3 apres traitement. Des coupes histologiques semi et ultra-fines au site de lesion a chaque temps etaient effectuees pour evaluer l’effet de la PDT-WST11. A J3, un montage a plat des retines et choroides etait realise apres perfusion du singe au dextran-FITC. Resultats A 25 J/cm2 aucune occlusion des NVC n’etait observee, quelle que soit la dose de WST11 ou le TI. Sur les coupes histologiques, les cellules de l’epithelium pigmentaire (EP) ou les photorecepteurs autour des impacts laser ne presentaient aucune lesion. Avec 100 J/cm2 et 5 mg/Kg WST11, TI une minute ou 5 minutes, une occlusion non selective des NVC et retiniens etait observee entrainant une ischemie retinienne. Avec WST11, 2,5 mg/Kg, et 50 J/cm2, TI 1 ou 5 minutes, on observait une occlusion selective et stable des NVC sur les angiographies sans occlusion des vaisseaux retiniens, confirmee sur les montages des retines et choroides a plat a J3 et en histologie a J3, J8 et J21. Aucune effusion intra ou sous retinienne n’a ete constatee meme aux temps precoces post PDT avec ces parametres. Conclusion En utilisant les parametres selectifs, WST11 cree une occlusion efficace, selective et stable des NVC chez le singe, sans effets collateraux notables. Ces donnees sont en cours de confirmation sur un essai clinique de phase IIa.

But Les auteurs presentent une nouvelle methode d’utiliser l’emission optique non lineaire engendree dans le tissu corneen par laser femtoseconde chirurgical pour des fins d’imagerie et de controle de l’intervention in situ . Materiels et Methodes Nous utilisons un laser femtoseconde Nd : verre du type CPA ( chirped pulse amplification ) de parametres techniques comparables aux lasers cliniques. Le faisceau laser est delivre au moyen d’un microscope optique inverse et focalise par des optiques d’ouvertures numeriques entre 0,15 et 1,2. L’emission optique creee par des processus du type generation de seconde harmonique peut etre captee par un detecteur optique connecte a une electronique d’acquisition. L’emission optique generee par le faisceau laser est enregistree en fonction de la position pour des energies d’impulsion en dessous du seuil de claquage. Des incisions sont induites utilisant des energies plus elevees. Les echantillons sont analyses par microscopie optique, microscopie electronique a transmission. Resultats L’amplitude du signal optique de seconde harmonique depend fortement de l’etat de la cornee (presence d’œdemes…) et de la profondeur du laser dans le tissu. Des mesures du signal a profondeurs variables permettent de determiner les constantes d’attenuation dans les cornees. Au-dessus du seuil d’ablation, des incisions de dimensions laterales microniques ont pu etre induites. A des energies meme legerement superieures au seuil, des effets secondaires deviennent visibles (cavites residuelles, densifications, effets thermiques). Discussion La variation de l’energie en fonction de la profondeur, en utilisant les valeurs pour l’attenuation precedemment determinees, permettait d’induire des incisions de qualite uniforme dans toute la profondeur dans des cornees meme fortement diffusantes. Conclusion Dans la chirurgie corneenne par laser femtoseconde, il s’est avere important de controler l’energie des impulsions pour eviter des effets secondaires non souhaites. L’analyse du signal optique non lineaire de seconde harmonique fournit un outil de mesure in situ non destructive de l’attenuation.

But Les auteurs presentent les resultats d’etudes histologiques et ultrastructurales des effets du laser femtoseconde sur des cornees humaines. Materiels et Methodes Nous utilisons un laser femtoseconde Nd : verre equipe d’un systeme CPA. La longueur d’onde est de 1 065 nm. La frequence de tir est ajustable de 1 a 10 kHz avec une energie maximale de 60 μ J. Le faisceau laser est delivre a travers un systeme de lentilles optiques fixe sur une table optique. Les cornees, delivrees par la banque francaise des yeux, sont fixees sur une chambre anterieure artificielle mobilisable dans les trois dimensions par des moteurs de precision micrometrique. Les cornees sont traitees par des energies laser comprises entre le seuil de plasma et 5 fois le seuil de plasma. Les echantillons sont analyses en microscopie optique et en microscopie electronique a transmission. Resultats Les decoupes realisees avec une energie proche du seuil de plasma sont de taille micrometrique. Les incisions realisees avec une energie de deux fois le seuil de plasma presentent une forte desorganisation des berges (effets de cavitations et probable effets thermiques localises). Discussion Ces resultats pourraient expliquer les cas de keratite lamellaire diffuse observes lors de femtolasik a trop forte energie. Ils confirment l’interet de realiser des decoupes au plus proche du seuil de plasma. Conclusion Au vu de ces resultats, il apparait que le developpement des futurs lasers passera par l’utilisation de frequences de repetition plus elevees.

The authors present four cases of Merkel cells tumor of the eyelid. These cases conform to the standard clinical and histological criteria specified in the dermatological literature. Immuno-histochemical studies have been performed (specific neuron enolase, cytokeratin KL 1). Il the last case an ultrastructural study has made evident the characteristic neurosecretory granulations and intermediate filaments. Various hypothesis concerning the origin of this tumor are discussed in light of anatomical evidence.

Acanthamoeba keratitis is a rare but very severe necrotizing stromal keratitis due to a non-parasitic free-living soil and freshwater amoeba. It affects more readily soft and hard lens wearers. It is often clinically mistaken for herpetic keratitis because of the similarity of the signs and the difficulty in performing the specific microbiological tests. This is the reason why the diagnosis is most often made at the time of penetrating keratoplasty and histological study of the buttons with special stains. Medical treatment is effective only when starting at the beginning of the disease.

Clear cell sarcoma of tendons and aponeuroses actually is a well identified soft tissue tumor. A primary orbital involvement is presented, with an optical and electron microscopic study. The orbital topography of such a tumor seems to be an exceptional opportunity. The histological study showed the typical pattern of this clear cell tumor. Ultrastructurally, there are not absolute specific features to establish the diagnosis, except the finding of intra-cellular melanosomes. Histogenesis has been debated for a long time between a melanotic or a synovial origin. According to present knowledge, this tumor may be attributed to a neural crest origin.

We analysed the histological and ultrastructural aspects of corneal buttons obtained by keratoplasty in two patients presenting breaks in Descemet's membrane. The edges of the breaks appear clinically as glassy ridges or ledges and are also called Haab's lines. One patient had a birth trauma and the other had congenital glaucoma. The edges of the breaks coiled anteriorly towards the stroma and were dramatically thickened by a multilaminar Descemet's like membrane that exhibited excrescences within its outer part and that was secreted by regenerated endothelial cells. Only one case was analysed by SEM. Secondary guttuta could not be detected by this technique because it was completely covered by a sheet of newly secreted fibrous tissue that prevented the warts from indenting the endothelial cells. The part of cornea corresponding to the break was also covered by a new thick Descemet's like membrane exhibiting guttate warts. This study is thus a good opportunity to discuss the mechanisms of endothelial and Descemet's membrane regeneration.

Histological and ultrastructural examination of the corneas of a woman presenting with marginal pellucid degeneration, treated by bilateral perforating keratoplasty, revealed obvious analogies with keratoconus. The condition of marginal pellucid degeneration is really only an excentric keratoconus. Marginal pellucid degeneration is a rare affection but it has been clinically sell defined. Many authors seem to have recognized it under various different names (cylindrical keratoconus, corneal protusion, piriform cornea). It is a pouch-shaped deformity of the cornea overlying a thinning of the linear stroma concentric to the limbus, always inferior and bilateral, perfectly transparent, non-vascularized, and without signs of corneal of conjunctival inflammation. The affection usually occurs in young adults.

The corneal oedema of acute keratoconus is related to a break in endothelial-Descemetic continuity. This break was confirmed by optical and electron microscopical study of an anatomical section taken during a perforating keratoplasty; the methods of repair were studied five months after the incident. The corneal endothelium had almost totally recoversed the surfaces of the detached Descemet's membrane and the posterior surface of the bare corneal stroma. Electron microscopic study tended to indicate that the endothelial repair occurred more by cellular extension rather than mitosis (very flat cells) and showed that the inter-cellular connecting systems (focal tight junctions) were not regular, or even absent altogether, which explained the clinical finding of persistant corneal oedema. The endothelial cells secrete a Descemet neo-membrane over all their area which is more or less complete. They revover an original scarred stroma of fibrocytes of the posterior stroma.

The biocompatibility of polytetrafluoroethylene (E. PTFE) keratoprosthetic skirts was studied for periods of observation from 4 to 14 weeks. In a first experimental study, the authors showed that E. PTFE was well tolerated but without fibrovascular ingrowth. In this study, eight perforating keratoplasties were performed and a disk of E. PTFE with a diameter of 4.5 mm was sutured in and covered with a conjunctival flap. The results show that E. PTFE allows fibrovascular ingrowth without a significant foreign body response or encapsulation. Coverage of E. PTFE with conjunctival was essential for fibrovascular ingrowth and to prevent extrusion and rejection.

Bilateral penetrating keratoplasties were performed in a case of Schnyder's crystalline stromal dystrophy and the buttons were examined by light and electron microscopy. Staining for lipids was negative probably because they had been dissolved during the dehydrating stage of the embedding process. In electron microscopy the deposits were highly suggestive of lipids. These deposits appeared as electron-lucent spaces, either empty and of regular geometrical form suggestive of cholesterol crystals, or smaller, rounded, and containing relative electron-lucent material also believed to be lipids. The crystals randomly accumulated in the superficial stroma, in Bowman's layer and in some basal epithelial cells, and the rounded spaces could be seen in all the layers of the stroma. Bowman's layer exhibited many disruptions. The endothelium and Descemet's membrane were unaffected. Our findings are compared with previous histological and electron microscopical reports.

Transfixing keratoplasty was performed in a patient seven years after a lens extraction, following the appearance of corneal edema with hypertony and proliferation of a retrocorneal veil. Scanning electron microscopy examination of the posterior surface of the removed graft demonstrated the presence of a vast cellular veil formed of epithelial cells. The principal characteristics of these cells were their polygonal shape, slightly raised edges, and the presence of numerous surface microvilli. Because of the particular characteristics of this epithelium, scanning electron microscopy can be used to observe mitoses in the deep layer as well as for differentiation of the superficial layers. The epithelial cell appears to be identical, as far as its evolution is concerned, both in the aqueous humor and when in contact with the lacrymal film. When compared with other modern investigational techniques, the scanning electron microscope appears to be an effective method for studying epithelial invasion of the anterior chamber. In fact, optical microscopy is of little value in such cases, and transmitted light electron microscopy too heavy a technique for the results expected. Scanning electron microscopy enables precise definition of epithelial cells and can confirm their corneal or conjunctival origin.

Terrien's disease is characterized by slowly progressive thinning of the pre-limbal cornea in middle-aged patients. It usually leads to peripheral ectasia with marked astigmatism. It is rarely accompagnied by inflammation and its cause is unknown. Very few histopathologic examinations have been published, in particular those using electron microscopy We present detailed results concerning 6 patients in whom perforating keratoplasty permitted histopathologic and electron microscopic examination. Clinical and histological features reveal marked degeneration of the peripheral corneal stroma, with lipid accumulation unaccompagnied by significant inflammatory cellular infiltration in each case. Of interest is the association in one patient with keratoconus. The generally accepted pathogenic theories are fully discussed. The wealth of electron microscopic data provides a complete review of stromal degenerative changes.

Keratoglobus is a bilateral corneal disease characterised by thinning and protrusion of the entire corneal surface. The cornea is of normal size and usually transparent. Acute corneal edema due to rupture of Descemet's membrane and perforation even from minimal trauma are the most frequent complications. Keratoglobus may be associated with blue sclera, hyperextensibility of the joints or auditory problems. Most often it is a congenital disease with autosomal recessive transmission, but it may be secondarily acquired to an advanced keratopathy (keratoconus), to trauma or to exophthalmos. We report 5 cases of keratoglobus. 4 patients underwent penetrating keratoplasty. The anatomical abnormalities of congenital keratoglobus (3 cases) are constants : an absent Bowman's membrane, a disorganized stroma containing granular material, a thickened, striated Descemet's membrane with breaks, folds and verrucosities. On the other hand, acquired keratoglobus (1 case) shows localised breaks in Bowman's membrane resembling those of keratoconus. The anatomopathological differences are discussed.

Cells of the superficial layer of the corneal epithelium demonstrate differences in luminosity on scanning electron microscopy which has led to their classification as clear, intermediate or dark cells, differences attributed to varying amounts of surface microvillosities. Evidence is provided confirming that differences between cells is not due to artefacts during preparation or observation of specimens. On the other hand, this technique cannot demonstrate whether different evolutory stages of the same cell are involved. Scanning microscopy cannot confirm a single evolutory epithelial cell are involved. Scanning microscopy cannot confirm a single evolutory epithelial cell cycle from the position of the cell in relation to adjacent desquamating cells, or the study of the cell nuclei. Nor can a satisfactory response to the problem be supplied by studying mucosubstances deposited by the lacrimal film on the surface of the epithelium, either by optical microscopy or after scanning electron microscopy with or without washing with acetylcysteine. The presence of superficial epithelial cells of different appearances on scanning microscopy must be due to variations in the amount of glycocalix, the mucus film adsorbed onto the cell surface.

The opportunity to follow the descendants of a family carrying the defect of a bilateral corneal lesion already described in the literature has led the authors to recommend surgical treatment and the lesions have been studied by light and electron microscopy. The two diagnoses are discussed: scleocornea and dermoid. They retain the latter diagnosis and give their reasons.

Optical, scanning and transmission electron microscopy examinations were performed in two cases of polymorphic posterior corneal dystrophy. The first case demonstrated typical clinical features, histologic examination revealing the presence of granular deposits in the posterior stroma, and an anarchic fibrillary zone between the stroma and Descemet's membrane. The latter was thickened, with a normal striated fetal zone, an intermediate zone composed of fibrils and long and short collagen fibers, and a normal adult zone. Cells lining the anterior chamber were of the typical endothelial type. Clinical signs in the second case were less evocative even though the father of the patient presented a typical form. Histology showed similar granular deposits in the posterior stroma, and the fibrillary zone beneath Descemet's membrane, which was thickened and delaminated and composed of three layers. Anterior chamber lining cells were disposed in several layers and had numerous surface microvillosities. They were linked by many desmosomes. These cells were therefore of the epithelial type. Comparing the findings in these two cases demonstrates that whereas many common signs existed there was a fundamental difference between the cell types on the posterior surface of the cornea. A review of all possible hypotheses led to the conclusion that the epithelial type cells are of mesenchymatous origin, similar to endothelial cells, as they possess the identical property of secreting a normal adult type of Descemet's membrane and of ensuring deturgescence of the corneal stroma. The pathological mechanisms involved, probably biochemical in nature, which provoke this anomaly can be fairly precisely determined as developing during fetal life, but they remain totally inexplicable. This hypothesis of a mesenchymatous cell developing into an epithelial type allows polymorphic posterior dystrophy to be regarded as a distinct entity, with similar features to other neonatal posterior dystrophies and a vast group of endothelial dystrophies including, among others, congenital edematous dystrophy.

A 6 month old white male infant had bilateral congenital diffuse sclerocornea. A penetrating keratoplasty was performed in his left eye. Histologic examination by electron microscopy demonstrated: the presence of vacuoles in the superficial epithelial layer, the absence of Bowman's membrane, a disorganization of collagen fibers and lamellae more prominent in the middle stroma, and an extremely thin Descemet's membrane. A comparison, using an automatized image analysis method, was carried out between the stroma of sclerocornea and a normal cornea. Morphometric analysis of the collagenous fibril's diameter and the interfibrillar distances demonstrated a statistically significant difference (p less than 0.001) between the two corneas examined.

Two cases of gelatinous drop-like dystrophy of the cornea in young North-African (Algeria, Tunisia) subjects are reported. Clinical examination revealed characteristic subepithelial gelatinous drops in the cornea. Histology showed the amyloid nature of the subepithelial deposits, their fibrillary from being demonstrated on ultrastructural examination. Lamellar keratoplasty did not prevent recurrences. A pathogenic hypothesis is suggested involving a role of epithelial induction in the fibroblast development.

In 1939, R. Turpin and al. described cases of hereditary and congenital corneal opacities in three generations of one family. The members of this family have since been followed-up regularly by the author, examination of the corneas of the grandmother and the grand'daughter made by electron microscopy, the morphology compared, and an attempt made to establish the progression of the lesion. It so happened that at the same time, witschel and al. published (June, 1978) the results of their examination of the American members of the same family. Their conclusions were the same, in that this familial congenital dystrophy of the cornea is mainly stromal and differs therefore from familial congenital endothelial dystrophies. The author's analysis is complementary to theirs.