Descemet's membrane injury and regeneration, and posterior corneal fibrosis, in rabbits.

The purpose of this investigation was to study Descemet's membrane and corneal endothelial regeneration, myofibroblast generation and disappearance, and TGF beta-1 localization after Descemet's membrane-endothelial excision (Descemetorhexis) in rabbits. Thirty-six rabbits had 8 mm Descemetorhexis and standardized slit lamp photos at 1, 2 and 4 days, 1, 2 and 4 weeks, and 2, 4 and 6 months, as well as multiplex IHC for stromal cell markers keratocan, vimentin, and alpha-smooth muscle actin (SMA); basement membrane (BM) components perlecan, nidogen-1, laminin alpha-5, and collagen type IV; and corneal endothelial marker Na,K-ATPase ß1, and TGF beta-1, with ImageJ quantitation. Stromal transparency increased from the periphery beginning at two months after injury and progressed into the central cornea by six months. At six months, central transparency was primarily limited by persistent mid-stromal neovascularization. Stromal myofibroblast zone thickness in the posterior stroma peaked at one month after injury, and then progressively decreased until to six months when few myofibroblasts remained. The regeneration of a laminin alpha-5 and nidogen-1 Descemet's membrane "railroad track" structure was accompanied by corneal endothelial closure and stromal cell production of BM components in corneas from four to six months after injury. TGF beta-1 deposition at the posterior corneal surface from the aqueous humor peaked at one day after Descemetorhexis and diminished even before regeneration of the endothelium and Descemet's membrane. This decrease was associated with collagen type IV protein production by corneal fibroblasts, and possibly myofibroblasts, in the posterior stroma. Descemet's membrane and the corneal endothelium regenerated in the rabbit cornea by six months after eight mm Descemetorhexis. Real-time quantitative RT-PCR experiments in vitro with marker-verified rabbit corneal cells found that 5 ng/ml or 10 ng/ml TGF beta-1 upregulated col4a1 or col4a2 mRNA expression after 6 h or 12 h of exposure in corneal fibroblasts, but not in myofibroblasts. Stromal cells produced large amounts of collagen type IV that likely decreased TGF beta-1 penetration into the stroma and facilitated the resolution of myofibroblast-generated fibrosis.

Bilateral descemet membrane detachment in femtosecond laser-assisted cataract surgery / Descolamento de descemet bilateral em cirurgia de catarata com laser de femtosegundo

Abstract We report an unusual case of a 65-year old patient that developed localized bilateral Descemet membrane detachment during non-simultaneous femtosecond laser-assisted cataract surgery (FLACS). The detachment occurred when the laser was performing the secondary incision. In the operating room, the isolate-and-release technique was used to effectively manage this complication. To the best of our knowledge, this is the first reported case of bilateral Descemet membrane detachment during FLACS.

Resumo Relatamos um caso de uma paciente de 65 anos de idade que evoluiu com descolamento de Descemet localizado bilateral durante cirurgias de catarata não simultâneas com laser de femtosegundo. O descolamento ocorreu durante a realização da paracentese pelo laser. Na sala cirúrgica, foi utilizada a técnica de "isolar e liberar" para conduzir eficazmente esta complicação. De acordo com o nosso conhecimento, esse é o primeiro relato de caso de descolamento bilateral da membrana de Descemet durante cirurgia de catarata com laser de femtosegundo.

Management of Descemet Membrane Detachment After Forceps Birth Injury.

PURPOSE: To describe the clinical signs of Descemet membrane (DM) detachment due to forceps-related birth injury and its subsequent management using optical coherence tomography. METHODS: Case report. RESULTS: A 3-day-old term infant presented with left eye corneal clouding and a definitive history of traumatic forceps-assisted delivery. Despite topical therapy, corneal clouding persisted, necessitating an examination under anesthesia using ultrasound and handheld optical coherence tomography. This revealed not only a tear in DM but also a large detachment. Injection of air alone failed to achieve apposition of DM to the posterior stroma. Apposition was achieved only after penetration of the overlying cornea with the needle of a 10-0 nylon suture and release of clear viscous fluid. The cornea cleared within the first week and continued in the months to follow. CONCLUSIONS: Prolonged corneal edema should alert the physician to probable DM detachment after forceps-related birth injury. Injecting air alone may not be sufficient to reattach the detached DM.

Ceratoplastia com recobrimento de terceira pálpebra em felino domésticopara o tratamento de descemetocele com perfuração de córnea / Keratoplasty with covering third eyelid in domestic feline for descemetocele treatment with corneal perforation

Background: Descemetocele is a lesion on the descemet’s membrane most often caused by very deep ulcerations in the cornea, where the epithelium, basement membrane and stroma layers are exposed, leading to a distortion of the corneal structure. Because it is an injury whose evolution can lead to loss of vision, Descemetocele is considered a surgical emergency because, within the various techniques adopted, there is always an attempt to preserve the ocular bulb. Thus, the adoption of various reconstructive keratoplasty procedures have been described in descemet’s membrane repair and ocular perforations of varying degrees of extension. In this surgical technique, tissue fragments (autogenous, autologous or xenologous) are usually used, the surgical method being defined according to the degree of injury (partial or total) and the amount of tissue required to be replaced. The aim of this study was to report a case of Keratoplasty with a third eyelid covering for descemetocele correction with corneal perforation in a domestic cat. Case: A 2-year-old feline female was treated at the Veterinary Hospital of the University of Amazonia (UNAMA), presenting a traumatic ocular lesion with evolution of more than 25 days, refractory to treatment as eye drops. The ophthalmologic examination revealed presence of extravasated polymerized necrotic tissue in the cornea of the left eye, with Descemetocele as diagnosis. The treatment indicated was Reconstructive Keratoplasty without graft with third eyelid coating. As an anesthetic protocol, MPA was used with acepromazine, ketamine hydrochloride as the inducing agent and isoflurane in mask vaporization for the maintenance of the anesthetic plane. After preparation of the patient, the surgical procedure consisted of excision with a scalpel blade of the necrotic tissue, exposure of the endothelial layer and suture of the cornea with Vincryl®, in a simple discontinuous pattern. […]

Ceratoplastia com recobrimento de terceira pálpebra em felino domésticopara o tratamento de descemetocele com perfuração de córnea / Keratoplasty with covering third eyelid in domestic feline for descemetocele treatment with corneal perforation

Background: Descemetocele is a lesion on the descemets membrane most often caused by very deep ulcerations in the cornea, where the epithelium, basement membrane and stroma layers are exposed, leading to a distortion of the corneal structure. Because it is an injury whose evolution can lead to loss of vision, Descemetocele is considered a surgical emergency because, within the various techniques adopted, there is always an attempt to preserve the ocular bulb. Thus, the adoption of various reconstructive keratoplasty procedures have been described in descemets membrane repair and ocular perforations of varying degrees of extension. In this surgical technique, tissue fragments (autogenous, autologous or xenologous) are usually used, the surgical method being defined according to the degree of injury (partial or total) and the amount of tissue required to be replaced. The aim of this study was to report a case of Keratoplasty with a third eyelid covering for descemetocele correction with corneal perforation in a domestic cat. Case: A 2-year-old feline female was treated at the Veterinary Hospital of the University of Amazonia (UNAMA), presenting a traumatic ocular lesion with evolution of more than 25 days, refractory to treatment as eye drops. The ophthalmologic examination revealed presence of extravasated polymerized necrotic tissue in the cornea of the left eye, with Descemetocele as diagnosis. The treatment indicated was Reconstructive Keratoplasty without graft with third eyelid coating. As an anesthetic protocol, MPA was used with acepromazine, ketamine hydrochloride as the inducing agent and isoflurane in mask vaporization for the maintenance of the anesthetic plane. After preparation of the patient, the surgical procedure consisted of excision with a scalpel blade of the necrotic tissue, exposure of the endothelial layer and suture of the cornea with Vincryl®, in a simple discontinuous pattern. […](AU)

Novel spatula and dissector for safer deep anterior lamellar keratoplasty / Uso de espátula e dissector para otimização da ceratoplastia lamelar anterior profunda (DALK)

Objective: We describe a novel spatula and dissector to facilitate the big-bubble technique in deep anterior lamellar keratoplasty (DALK). Methods: A 29-year-old man who was diagnosed with bilateral keratoconus underwent deep anterior lamellar keratoplasty (DALK). After 350μm partial thickness incision of the recipient cornea, the Bonfadini dissector was inserted at the deepest point in the peripheral incision and could be advanced to the center of the cornea safely because of its "semi-sharp" tip. After achieving the big-bubble (BB) separation of Descemet membrane (DM) from the overlying stroma, the anterior stromal disc was removed. Viscoelastic material was placed on the stromal bed to prevent uncontrolled collapse and perforation of DM during the paracentesis blade incision into the BB. We could detect the safe opening of the BB using the Bonfadini dissector by the leakage of air bubbles into the viscoelastic material. After injecting viscoelastic material into the BB space, we inserted the Bonfadini spatula into the bigbubble safely because of its curved profile and blunt edges. The groove along the length of the Bonfadini spatula enables safe and efficient incision or the residual stromal tissue using the pointed end of a sharp blade while protecting the underlying DM. After removal of posterior stroma, the donor button was sutured with 16 interrupted 10-0 nylon sutures. Results: This technique and the use of the Bonfadini spatula and dissector facilitate exposure of Descemet membrane. Conclusion: The smooth Bonfadini DALK spatula and dissector facilitate safe and efficient completion of DALK surgery. .

Objetivo: Descrevemos o uso de novos instrumentais cirúrgicos para facilitar a técnica de "big-bubble" na ceratoplastia lamelar anterior profunda (DALK). Métodos: Paciente masculino, 29 anos, foi diagnosticado com ceratocone bilateral e submetido à ceratoplastia lamelar anterior profunda (DALK). Após incisão da córnea receptora numa profundidade de 350μm de espessura parcial, o dissector Bonfadini foi inserido no ponto mais profundo da incisão periférica e pode avançar para o centro da córnea com segurança devido à sua ponta semiafiada. Depois de realizar a "big-bubble" (BB) e atingir a separação da Membrana de Descemet (MD) do estroma sobrejacente, o disco corneano de estroma anterior foi removido. Um viscoelástico foi colocado sobre o leito do estroma remanescente para impedir o colapso não-controlado e perfuração da MD durante a incisão na BB com lâmina de paracentese. Verificamos segurança no rompimento do estroma remanescente com o auxílio do dissector Bonfadini, para liberação da bolha de ar da BB através do viscoelástico. Depois de injetar o viscoelástico no espaço da BB, inserimos a espátula Bonfadini neste espaço, o que demonstrou-se seguro devido ao formato curvo e das bordas arredondadas do instrumental. A chanfradura ao longo do comprimento da espátula Bonfadini permite a incisão pela ponta de uma lâmina afiada, protegendo assim a MD subjacente. Após a remoção do estroma posterior, o botão doador foi suturado com 16 pontos interrompidos de fio nylon 10.0. Resultados: Esta técnica e o uso da espátula Bonfadini e dissector facilitam a exposição de membrana de Descemet. Conclusão: A superfície lisa da espátula Bonfadini e dissector, facilitam a realização segura e eficiente da ceratoplastia lamelar anterior profunda (DALK). .

O papel da membrana de Descemet na patogenia do edema corneano após cirurgia de segmento anterior / The role of Descemet's membrane in the pathogeny of corneal edema following anterior segment surgery

Objetivo: Encontrar fatores importantes na patogenia do edema corneano pós-cirúrgico, em casos de pós-facectomia e pósceratoplastia, por meio do estudo dos achados histopatológicos, a fim de ver o que pode ser feito para evitar sucessivas ceratoplastias. Métodos: Estudo retrospectivo descritivo das alterações histopatológicas de casos de edema corneano pós-cirúrgicos. Os tecidos foram provenientes de ceratoplastia penetrante no período compreendido entre setembro de 2009 e agosto de 2013. Foi realizada revisão de prontuários em busca principalmente de informações sobre cirurgias prévias. Resultados: Foram incluídos 70 botões corneanos, sendo 34 de pacientes do sexo masculino e 36 do sexo feminino. A média das idades foi de 63,1±17,20 (média ± DP) anos. A maioria dos casos era de falência após transplante (71,43%). A rarefação celular foi a principal alteração encontrada no endotélio (58 casos), sendo também a alteração histopatológica mais frequente. Na membrana de Descemet, predominaram as alterações de integridade (53 casos), seja na forma de ruptura, de descolamento isolado ou de descolamento associado à ruptura. Foi frequente a associação de alterações endoteliais à ausência da integridade da membrana de Descemet. Conclusão: Descolamento da membrana de Descemet é um achado histopatológico frequente nos casos de edema corneano pós-cirúrgicos estudados, devendo ser considerado um fator importante na patogenia dos mesmos. Essa alteração deve ser procurada com atenção nos pós-operatórios, a fim de ser diagnosticada e tratada precocemente, vindo possivelmente a evitar muitas indicações de ceratoplastia. .

Objective: To find relevant factors in the pathogeny of postoperative corneal edema in post-cataract surgery and post-keratoplasty cases, through the study of histopathological findings in order to see what can be done to avoid successive keratoplasties. Methods: Retrospective descriptive study of histopathological findings in postoperative corneal edema cases. Tissues were obtained from penetrating keratoplasty in the period between september 2009 and august 2013. A medical record review was conducted primarily looking for information about previous surgeries. Results: Seventy corneal buttons were included, out of which 34 were from male patients and 36 were from female patients. The mean age was 63.1±17.20 (mean ± SD) years. Most of cases were corneal failure after keratoplasty (71.43%). The main change found in endothelium was cellular rarefaction (58 cases), and it was also the most common histopathological change. Changes in integrity predominated in Descemet's membrane (53 cases), whether in the form of rupture, isolated detachment or detachment associated with rupture. Endothelial changes associated with the absence in Descemet's membrane integrity were frequent. Conclusion: Descemet's membrane detachment is a frequent histopathological finding in postoperative corneal edema cases studied, thus it should be considered an important factor in the pathogeny of such cases. This change should be carefully researched in the postoperative period in order to be diagnosed and treated early, possibly avoiding many keratoplasty indications. .

[Technique for separating Descemet membrane for corneal endothelial cells transplantation: experimental study in rabbits]. / Técnica de separação da membrana de Descemet para transplante de células endoteliais da córnea: estudo experimental em coelhos.

PURPOSE: To evaluate the percentage of endothelial cell damage induced during a surgical technique of Descemet's membrane separation containing healthy endothelium, analyze the viability and efficacy of this technique, and evaluate the percentage of endothelial cell damage caused by inversion of the cornea on an artificial anterior chamber. METHODS: The corneas from three groups of 12 New Zealand rabbits were evaluated. The Group one was used as the control, so the corneas were analyzed after collected and trephinated. The Group two was analyzed after inversion of the cornea (endothelial side up at a convex shape) mounted on an artificial anterior chamber to calculate the percentage of endothelial cell damage caused by this inversion. The Group three was evaluated after the separation between the Descemet's membrane and the stroma using viscoelastic substance in corneas inverted and mounted on an artificial anterior chamber. The endothelial cell damage was analyzed by digital photographs taken under a microscope after staining the endothelium with alizarin red. Group three samples were processed for histologic evaluation. RESULTS: The Group three (viscoelastic separation) showed an index of endothelial cell damage of 10.06%, the Group two showed an index of 3.58% and the control group an index of 0.18% of endothelial cell damage (p<0.05). Histological evaluation of the Group three corneas revealed that approximately a 120 microm thickness of stroma remained attached to the Descemet's membrane. CONCLUSION: This technique should be better investigated because it is a viable and efficient alternative of Descemet's membrane separation for endothelial cells transplantation, since the percentage of induced cell damage is 10.06%. The percentage of endothelial cell damage caused by inversion of the cornea on an artificial anterior chamber was 3.58%.

Técnica de separação da membrana de Descemet para transplante de células endoteliais da córnea: estudo experimental em coelhos / Technique for separating Descemet membrane for corneal endothelial cells transplantation: experimental study in rabbits

OBJETIVO: Avaliar a porcentagem de dano endotelial induzido por uma técnica cirúrgica para a separação da membrana de Descemet contendo endotélio sadio, analisar a viabilidade e eficácia desta técnica, e avaliar a porcentagem de dano endotelial causado pela inversão da córnea em câmara anterior artificial. MÉTODOS: As córneas de três grupos de 12 coelhos da linhagem Nova Zelândia foram avaliadas. O grupo 1 foi usado como controle; portanto, as córneas foram analisadas após coletadas e trepanadas. O grupo 2 foi analisado após a inversão da córnea (endotélio para cima na posição convexa), montada em câmara anterior artificial, para o cálculo da porcentagem do dano endotelial induzido por esta inversão. O grupo 3 foi avaliado após a separação entre a membrana de Descemet e o estroma com o uso de substância viscoelástica em córneas invertidas e montadas em câmara anterior artificial. O dano endotelial foi avaliado por meio de fotografias digitais tiradas no microscópio após impregnar o endotélio com vermelho de alizarina. Amostras do grupo 3 foram processadas para avaliação histopatológica. RESULTADOS: O grupo 3 (separação viscoelástica) apresentou um índice de lesão celular endotelial de 10,06 por cento, o grupo 2 apresentou um índice de 3,58 por cento e o grupo controle um índice de 0,18 por cento de lesão celular endotelial (p<0,05). A avaliação histológica das córneas do grupo 3 revelou que aproximadamente 120 µm de espessura estromal manteve-se aderido à membrana de Descemet. CONCLUSÃO: Esta técnica deve ser melhor investigada, pois é uma alternativa viável e eficaz de separação da membrana de Descemet para transplante celular endotelial, já que o porcentual de dano celular induzido é de 10,06 por cento. A porcentagem de dano celular causado pela inversão da córnea em câmara anterior artificial foi de 3,58 por cento.

PURPOSE: To evaluate the percentage of endothelial cell damage induced during a surgical technique of Descemet's membrane separation containing healthy endothelium, analyze the viability and efficacy of this technique, and evaluate the percentage of endothelial cell damage caused by inversion of the cornea on an artificial anterior chamber. METHODS: The corneas from three groups of 12 New Zealand rabbits were evaluated. The Group one was used as the control, so the corneas were analyzed after collected and trephinated. The Group two was analyzed after inversion of the cornea (endothelial side up at a convex shape) mounted on an artificial anterior chamber to calculate the percentage of endothelial cell damage caused by this inversion. The Group three was evaluated after the separation between the Descemet's membrane and the stroma using viscoelastic substance in corneas inverted and mounted on an artificial anterior chamber. The endothelial cell damage was analyzed by digital photographs taken under a microscope after staining the endothelium with alizarin red. Group three samples were processed for histologic evaluation. RESULTS: The Group three (viscoelastic separation) showed an index of endothelial cell damage of 10.06 percent, the Group two showed an index of 3.58 percent and the control group an index of 0.18 percent of endothelial cell damage (p<0.05). Histological evaluation of the Group three corneas revealed that approximately a 120 µm thickness of stroma remained attached to the Descemet's membrane. CONCLUSION: This technique should be better investigated because it is a viable and efficient alternative of Descemet's membrane separation for endothelial cells transplantation, since the percentage of induced cell damage is 10.06 percent. The percentage of endothelial cell damage caused by inversion of the cornea on an artificial anterior chamber was 3.58 percent.

Manjeo del desprendimiento de la membrana de Descemet / Descemet's membrane detachment management

Reportamos 4 casos de desprendimiento de la membrana de Descemet (DMD) y presentamos una breve revisión del manejo de estos casos

Degeneración marginal de Terrien. Reporte de un caso en una menor de 7 años / Terrien's marginal degenration. Case report

La degeneración marginal de Terrien, enfermedad no inflamatoria que afecta la córnea periférica, generalmente se presenta en individuos de edad media y es habitualmente unilateral al inicio, tendiendo posteriormente a la bilateralidad. Consiste en una delgazamiento de la córnea periférica que cursa sin afección epitelial y que en su borde de avance muestra infiltrados lipídos. Se presenta un caso de la enfermedad en una niña de 7 años