Caracterización de la membrana basal, los plexos nerviosos y el grosor corneal mediante microscopia confocal en pacientes diabéticos / Characterization of basal membrane, nervous plexus and corneal thickness by confocal microscopy in diabetic patients

RESUMEN Objetivo: Identificar las características morfológicas y morfométricas de las capas de la córnea mediante microscopia confocal en pacientes diabéticos. Métodos: Se realizó un estudio descriptivo, comparativo, en 90 ojos, 60 de ellos pertenecientes a pacientes diabéticos (30 tipo 1 y 30 tipo 2) y 30 a pacientes supuestamente sanos. El estudio se realizó en el Instituto Cubano de Oftalmología "Ramón Pando Ferrer" entre enero del año 2012 y enero de 2017. Resultados: El espesor del epitelio, el estroma y el endotelio corneal fue mayor en los ojos de diabéticos tipo 1 con una media de 54,6; 506,7 y 26,7 micras respectivamente. La membrana basal epitelial se observó en el 20 por ciento de los ojos de pacientes con diabetes mellitus tipo 1, y en el 10 por ciento de los diabéticos tipo 2. El grupo de diabéticos tipo 1 mostró uno y dos plexos nerviosos por campo de microscopia confocal para el 33,3 por ciento cada uno. En los diabéticos tipo 2, predominó un plexo nervioso (40 por ciento) y en pacientes sanos predominaron 4 plexos nerviosos (66,7 por ciento). Ambos grupos de pacientes diabéticos presentaron plexos verticales tortuosos (40 por ciento y 53,3 por ciento respectivamente) y plexos nerviosos oblicuos en el grupo de pacientes supuestamente sanos (80 por ciento). Conclusiones: El estudio de la córnea por microscopia confocal en pacientes diabéticos evidencia mayor espesor corneal total y por capas, membrana basal visible, disminución del plexo nervioso sub-basal con disposición vertical y tortuosidad de las fibras(AU)

ABSTRACT Objective: To identify the morphological and morphometric characteristics of the corneal layers by confocal microscopy in diabetic patients. Methods: A descriptive and comparative study was carried out in 90 eyes, 60 of which belonged to diabetic patients (30 type 1 and 30 type 2) and 30 to supposedly healthy patients. The study was conducted at Ramón Pando Ferrer Cuban Institute of Ophthalmology, between January 2012 and January 2017. Results: Epithelial thickness, stroma and corneal endothelium was greater in the eyes of type 1 diabetics with a mean of 54.6, 506.7 and 26.7 microns, respectively. The epithelial basement membrane was observed in 20 percent of the eyes of patients with type 1 diabetes mellitus, and in 10 percent of type 2 diabetics. The group of type 1 diabetics showed one and two nerve plexuses per confocal microscopy field for 33.3 percent each. In type 2 diabetics, one nerve plexus (40 percent) predominated, while in healthy patients, four nerve plexuses (66.7 percent) predominated. Both groups of diabetic patients presented tortuous vertical plexuses (40 percent and 53.3 percent, respectively) and oblique nerve plexuses in the group of supposedly healthy patients (80 percent). Conclusions: The study of the cornea by confocal microscopy in diabetic patients showed greater total and layered corneal thicknesses, visible basal membrane, decrease in the sub-basal nerve plexus with vertical arrangement, and tortuous fiber(AU)

Concordancia entre los diferentes conteos celulares según los parámetros morfológicos y morfométricos del endotelio corneal / Concordance between different cell counts according to morphologic and morphometric parameters of the corneal endothelium

RESUMEN Objetivo: Estimar los valores morfológicos y morfométricos del endotelio corneal según la cantidad de células y evaluar la concordancia interobservadores para los diferentes parámetros, considerados según los diferentes conteos celulares en adultos sin alteraciones corneales. Métodos: Se realizó una investigación observacional, descriptiva y transversal de serie de casos en el Servicio de Cirugía Refractiva del Instituto Cubano de Oftalmología "Ramón Pando Ferrer" en dos años de estudio. Después de aplicar los criterios de exclusión, la muestra quedó conformada por 200 ojos de 100 pacientes adultos sin alteraciones corneales. Se realizó microscopia endotelial de no contacto SP-3000P, para identificar los valores morfológicos (hexagonalidad y coeficiente de variabilidad) y morfométricos (densidad celular), así como el promedio del tamaño celular corneal según cantidad de células evaluadas. Resultados: Según la cantidad de células endoteliales evaluadas, no existieron diferencias significativas de las variables morfológicas y morfométricas (p> 0,05) en ambos ojos. La concordancia entre los diferentes conteos celulares según los valores de los coeficientes de correlación intraclase fueron todos altos. La concordancia interobservadores (excepto para la hexagonalidad) y los coeficientes de correlación intraclase fueron altos. Conclusiones: Los valores morfológicos y morfométricos del endotelio corneal según cantidad de células evaluadas, son similares en todos los conteos celulares. Se demuestra una buena concordancia entre los diferentes conteos celulares estudiados para los diferentes parámetros estimados(AU)

ABSTRACT Objective: To estimate the morphological and morphometric values of the corneal endothelium according to the number of cells and evaluate the interobserver concordance for the different parameters, estimated according to the different cell counts in adults without corneal alterations. Methods: An observational, descriptive and cross-sectional case series research was carried out in the Refractive Surgery Service of Ramón Pando Ferrer Cuban Institute of Ophthalmology during two years of study. After applying the exclusion criteria, the sample was made up of 200 eyes of 100 adult patients without corneal alterations. Non-contact endothelial microscopy SP-3000P was performed to identify morphological values (hexagonality and coefficient of variability) and morphometric values (cell density), as well as the average corneal cell size according to the number of cells evaluated. Results: According to the amount of endothelial cells evaluated, there were no significant differences between morphological and morphometric variables (p>0.05) in both eyes. The agreement between the different cell counts according to the values of the interclass correlation coefficients (ICC) were all high. The interobserver concordance and ICCs were also high, except for hexagonality. Conclusions: The morphological and morphometric values of the corneal endothelium, according to the number of cells evaluated, are similar in all cell counts. Good concordance between the different cell counts studied for the different estimated parameters is demonstrated(AU)

Endothelial assessment of donated tectonic corneas: a viable option for posterior lamellar transplantation / Avaliação da viabilidade do uso de córneas tectônicas em transplantes lamelares posteriores a partir da análise da vitalidade das células endoteliais

ABSTRACT Purpose: Donated corneas are classified as tectonic if there are defects within any layers of the cornea which would prevent a satisfactory visual outcome after transplantation. This study aimed to evaluate whether some tectonic corneas have sufficient endothelial characteristics to allow their use in posterior lamellar keratoplasty, and explored their reclassification for use in this sight-improving procedure. Methods: A retrospective review of all corneal tissues preserved by the Sorocaba Eye Bank from January to April of 2014 was performed. All donated corneas classified as tectonic were included. Endothelial tissue was defined as healthy and viable for posterior lamellar keratoplasty if endothelial cell density was ≥2000 cells/mm2. Additional parameters analyzed included Descemet folds and stretch marks, loss of endothelial cells, corneal endothelial polymegathism/ pleomorphism, pseudo-guttata, and reflectivity. Results: During the study period, 2,847 corneas were preserved, of which 423 (14.85%) were classified as tectonic. Of these, 87 (20.56%) were reported as having endothelial viability and were included in the posterior lamellar keratoplasty group. Average corneal endothelial cell density of this group was 2,471 SD ± 256 cells/mm2 (range 2012-2967 cells/mm2). Conclusion: A significant number of corneas classified as tectonic showed endothelial viability and were included in the posterior lamellar keratoplasty group (20.56%). Despite stromal and/or epithelial alterations, these corneas could have been potentially distributed for posterior lamellar transplantation to improve vision, thus reducing the corneal transplantation waiting period. This study highlights how corneal tissue reclassification could increase the potential amount of corneal tissue available for optical transplantation.

RESUMO Objetivo: Avaliar a vitalidade endotelial das córneas classificadas como tectônicas e discutir a viabilidade de seu uso na ceratoplastia lamelar posterior. Métodos: Realizou-se uma revisão retrospectiva de todos os tecidos corneanos preservados pelo Banco de Olhos Sorocaba de janeiro a abril de 2014. Todas as córneas doadas classificadas como tectônicas foram incluídas e avaliadas com ênfase na vitalidade endotelial. Os parâmetros de avaliação da lâmpada de fenda de cada córnea e densidade de células endoteliais medidos por microscópio especular foram registrados: córneas que apresentavam vitalidade endotelial apesar de alterações no estroma e/ou no epitélio foram selecionadas e incluídas em um grupo denominado grupo lamelar posterior. O tecido endotelial foi definido como saudável e viável para a ceratoplastia lamelar posterior, se houvesse uma densidade de células endoteliais ≥2.000 células/mm2. Outros parâmetros também foram analisados, incluindo; estrias ou pregas na Descemet, perda de células endoteliais, polimegatismo e pleomorfismo endotelial, pseudo-guttata e reflexividade endotelial. Resultados: Durante o período do estudo, foram preservadas 2.847 córneas, das quais 423 (14,85%) foram classificadas como tectônicas. Dessas, 87 (20,56%) apresentaram vitalidade endotelial e foram incluídos no grupo lamelar posterior. A densidade média das células endoteliais da córnea deste grupo era de 2.471 SD ± 256 células/mm2, variando de 2.012 a 2.967 células/mm2. Conclusão: Um número significativo de córneas classificadas como tectônicas apresentaram vitalidade endotelial e foram incluídas no grupo lamelar posterior (20,56%). Apesar de alterações estromais e/ou epiteliais, estas córneas poderiam ter sido potencialmente distribuídas para transplantes lamelares posteriores com finalidade ótica, otimizando a disponibilidade de tecidos, com impacto positivo na saúde pública.

Morfología y morfometría del endotelio corneal / Morphometry and morphology of the corneal endothelium

El estudio de parámetros morfológicos y morfométricos del endotelio corneal en poblaciones de individuos sanos ha sido motivo de diversas investigaciones a nivel internacional en los últimos años. La microscopia especular permite una visión clara de las células endoteliales vivas sin alterar su función ni su morfología. A su vez, se puede realizar un recuento por área de superficie y determinar si existe una alteración en la forma o tamaño de las células endoteliales, parámetros a tener en cuenta para conocer la capacidad funcional del endotelio corneal. Se realizó una búsqueda actualizada de los últimos diez años de diversos artículos publicados, con el objetivo de conocer las características cuantitativas y cualitativas de las células endoteliales en las diferentes poblaciones estudiadas. Se utilizó la plataforma Infomed, específicamente la Biblioteca Virtual de Salud(AU)

The study of morphological and morphometric parameters of the corneal endothelium in healthy individuals have been the main subject of several research studies at international level in the last few years. The specular microscopy allows us a clear vision of the alive endothelial cells without altering either their function or their morphology; a counting per surface area can be made and to determine whether an alteration exists in the form or the size of the endothelial cell, this is a parameter to be kept in mind to know the functional capacity of the corneal endothelium. An updated search of the published articles in the last ten years was made with the objective of determining the quantitative and qualitative characteristics of the endothelial cells in the different studied populations. Infomed platform, particularly the Virtual Library of Health, was used to this end(AU)

Endotelio corneal de riesgo en pacientes con indicación de cirugía de catarata / Risky corneal endothelium in patients with indication of cataract surgery

Objetivo: identificar el riesgo de edema relacionado con los parámetros morfofuncionales del endotelio corneal en pacientes con indicación de cirugía de catarata. Métodos: se realizó un estudio descriptivo, transversal en 200 ojos de pacientes en la consulta preoperatoria de cirugía de catarata. Las variables estudiadas fueron edad, sexo, riesgo de edema, pleomorfismo y polimegatismo para lo cual se examinó a cada uno de ellos con microscopia especular. Además se examinaron en lámpara de hendidura en busca de la presencia de guttas corneales. Resultados: se obtuvo una edad media de 70,7 años y existió un predominio de las mujeres (67,7 por ciento) frente a los hombres (32,3 por ciento). No hubo riesgo de edema en un 80,5 por ciento y sí lo hubo en 39 ojos para un 19,5 por ciento. Se relacionó el polimegatismo y la edad estando presente en 176 ojos para un 88,0 por ciento y con un predominio del estadio leve en todos los grupos de edades con un 80,5 por ciento. El pleomorfismo estuvo presente en 186 ojos (93 por ciento) y de ellos 103 (51,5 por ciento) se encontraron en el estadio leve y 78 (39,0 por ciento) en el moderado. Conclusiones: la disminución de la densidad celular no es el único parámetro que indica que un endotelio es de riesgo para una cirugía de catarata, otros como el polimegatismo, el pleomorfismo, así como la presencia de guttas; también son de importancia

Objective: to identify the risk of edema associated with the morphological and functional parameters of the corneal endothelium in those patients with indication of cataract surgery. Methods: a cross-sectional and descriptive study was performed in 200 eyes from the patients attending the preoperative cataract surgery service. The studied variables were age, sex, risk of edema, pleomorphism and polymegatism. Each patient was examined with the specular microscopy and also a slit-lamp examination was made to look for cornea guttata. Results: the average age of the group was 70.7 years, with females predominating (67.7 percent) over males (32.3 percent). There was no risk of edema in 80.5 percent of cases whereas the risk was present in 19.5 percent (39 eyes). Polymegatism and age were associated, being this problem present in 176 eyes for 88 percent of the total number and predominant in its mild staging in all the age groups for 80.5 percent. Pleomorphism affected 186 eyes (93 percent) and 103 of them (51.5 percent) was at the mild staging and 78 (39 percent) at the moderate staging. Conclusions: reduction in the cell density is not the only parameter indicative of a risky endothelium for a cataract surgery, since others such as polymegatism, pleomorphism and presence of cornea guttata are also important

Cornea stress test--evaluation of corneal endothelial function in vivo by contact lens induced stress.

Reliable and valid assessment of corneal endothelial function is a critical input for diagnosing, prognosticating and monitoring progression of disorders affecting corneal endothelium. In 123 eyes, corneal endothelial function was assessed employing data from the corneal hydration recovery dynamics. Serial pachometric readings were recorded on Haag-Striet pachometer with Mishima-Hedbys modification before and after two hours of thick soft contact lens wear. Percentage Recovery Per Hour (PRPH) was derived from raw data as an index of endothelial function. Assessed PRPH in pseudophakic corneal oedema and Fuchs' endothelial dystrophy eyes (35.9 +/- 9.8%) was significantly lower than normal controls (61.9 +/- 10.5%). On employing receiver operation characteristics curve analysis the tested results demonstrated high sensitivity (87%) and specificity (92%) for detection of low endothelial function at PRPH cut off of 47.5%. Using this PRPH cut off, 80% of Fuchs' endothelial dystrophy and 93.3% of pseudophakic corneal oedema eyes could be demonstrated to have low endothelial function. A total of 66.7% of diabetic eyes also demonstrated PRPH of lower than 47.5%. Clear corneal grafts demonstrated PRPH values of 24.6% to 73.0%. Of 6 corneal grafts that demonstrated initial PRPH of lower than 47.5%, 4 failed within 4 to 6 months. Our data demonstrated high sensitivity and specificity of this corneal stress test. PRPH index was useful in quantifying endothelial function in clinical disorders including diabetes mellitus. The index PRPH was demonstrated to be useful in monitoring and prognosticating outcome of corneal grafts.

Estudo do endotélio corneano em portadores de diabetes mellitus tipo II por microscopia especular de córnea / Study of the corneal endothelium of carrier of diabetes mellitus type II by specular microscopy of the cornea

Utilizando a microscopia especular de córnea, foram analisados e comparados os endotélios corneanos de 120 indivíduos, 24 não portadores de Diabetes mellitus (grupo controle), e os demais portadores de Diabetes mellitus tipo II, 24 sem retinopatia diabética, 24 com retinopatia diabética leve a moderada, 24 com retinopatia não proliferativa severa e 24 com retinopatia proliferativa. Constatou-se densidade endotelial média no grupo controle, de 2366 ñ 227 células/mm², polimegatismo 1,56 ñ 0,26 e pleomorfismo 0,19 ñ 0,02. A análise estatística (teste F associado à análise da variância e pelo teste de Dunnett) não demonstrou diferença significativa entre o polimegatismo endotelial dos grupos sem retinopatia diabética e com retinopatia diabética leve a moderada, o que ocorreu nos grupos com retinopatia diabética não proliferativa severa e retinopatia diabética proliferativa. Não foi observada diferença significativa entre a densidade endotelial e pleomorfismo nos grupos estudados. Pondera-se sobre maiores cuidados na utilização de córneas de portadores de Diabetes mellitus com retinopatia diabética não proliferativa severa e retinopatia diabética proliferativa em transplantes de córnea com finalidade óptica.

Endotélio corneano: microscopia especular / Corneal endothelium: specular microscopy

O autor historia os fatos que possibilitaram um melhor exame do endotélio corneano. Após explicar suscintamente a microscopia especular com e sem contato, conclue das suas vantagens, em especial a possibilidade do exame "in vivo". Estuda a importância desta camada corneana, bem como sua fisiologia e alteraçöes que pode sofrer com o envelhecimento, traumatismos diretos, cirurgias, drogas e irrigaçäo da câmara anterior. Avalia a importância do estudo especular de córneas a serem transplantadas