Variability in the Epithelial Expression of Ki67 and Polarization Characteristics of Collagen in Odontogenic Cysts and Tumours

ABSTRACT Objective: To assess the proliferation of epithelium (using the Ki67 index) and the polarization pattern of collagen in selected odontogenic cysts and tumours. In addition, an exploratory analysis of the effect of inflammation on the proliferation rate was done. Material and Methods: Following immunohistochemical staining, the labelling/proliferation index of Ki67 was calculated. The thickness and corresponding polarization colour of 100 juxta-epithelial picrosirius red-stained collagen fibers were assessed using linear micrometry with an eyepiece reticule under × 1000 magnification. Inflammation was graded subjectively as mild, moderate, and severe. Results: Overall Ki-67 expression was higher in the radicular cyst, Odontogenic Keratocyst, Ameloblastoma, while suprabasal Ki-67 positivity was maximum in Odontogenic Keratocyst. The stromal collagen fibers in Ameloblastoma showed predominantly green birefringence, whereas Odontogenic Keratocyst had orange birefringence. There was no significant association of inflammation with Ki-67 expression or birefringence patterns. Conclusion: The highest Ki67 expression in the radicular cyst, followed by Odontogenic Keratocyst and Ameloblastoma. Differences in the collagen maturation pattern were noted innately in five lesions studied and were further influenced by inflammatory changes. Epithelial proliferation and concomitant expression of thickness and maturity of the stromal collagen are innate features of the lesion further influenced by inflammation in various odontogenic cysts and tumours and may, in turn, guide the clinical behavior.

Collagen fibers in oral submucous fibrosis - A polarizing microscopy study using two special stains

Background: Oral submucous fibrosis (OSMF), a well-recognized oral potentially malignant disorder, results due to increased collagen production and reduced collagen degradation. Aims and Objectives: To qualitatively compare the staining properties of collagen in OSMF using two special stains based on their birefringent property using polarizing microscopy. The study also assessed the distribution and orientation of collagen fibers in different grades of OSMF. Materials and Methods: A total of 73 subjects with different clinical and histopathological staging of OSMF comprised the study population. Histopathological examination was done using hematoxylin and eosin stain, Van Gieson and picrosirius red. Collagen fibers were analyzed for polarization colors, distribution, and orientation. Results: Picrosirius red stained both thick and thin collagen fibers. Irrespective of the histopathological grades reddish orange and yellowish orange were the most predominant colors. Parallel arrangement of fibers was observed when stained with Van Gieson but picrosirius red stained sections showed a majority of parallel type I fibers with perpendicular type III fibers which increased with advancement in the histopathological grade. Yellowish orange and greenish yellow fibers were predominant in the lamina propria, while reddish orange fibers were predominant in the submucosa. Conclusion: Picrosirius red was found to be a better stain. Histopathological grading and polarization colors showed no association with each other. Collagen fibers were more thickly and tightly packed in the submucosa indicating that the process of fibrosis began there. The increase in perpendicular type III fibers with advancing histopathological grades suggested their role in fibrosis.

Clinical features and corneal optical anisotropies in a rabbit model of limbal stem cell deficiency / Fenótipos clínicos e anisotropias ópticas da córnea em coelhos com deficiência de células tronco limbais

ABSTRACT Purposes: To investigate the intra-laboratory reproducibility of clinical features and to evaluate corneal optical anisotropies in a rabbit model of limbal stem cell deficiency. Methods: Limbal injury was induced in the right eye of 23 adult New Zealand White rabbits using a highly aggressive protocol that combined 360 degrees limbal peritomy, keratolimbectomy, alkaline chemical burn, and mechanical removal of the epithelium. Clinical evaluation of the injured eyes was performed for 28 days and included corneal impression cytology. Corneas with a severe clinical outcome set typical of limbal stem cell deficiency were then collected, subjected to a histopathological examination, and examined for optical anisotropies. Corneas from healthy rabbit eyes were used as controls. Differences in optical path due to stromal collagen birefringence, as well as linear dichroism related to the expression and spatial orientation of glycosaminoglycan chains from proteoglycans, were measured from cross-sections under a quantitative polarized light microscope. Results: One eye showed signs of hypopyon and was excluded. Signs of ocular inflammation were observed in all eyes studied (n=22). Corneal impression cytology did not detect goblet cells. Twelve of the 22 corneas presented a clinical outcome set typical of limbal stem cell deficiency, which is characterized by the presence of epithelial defects, inflammatory cells, moderate-to-severe opacity, and neovascularization. Microscopic studies under polarized light revealed that relative to controls, limbal stem cell deficiency caused a 24.4% increase in corneal optical path differences. Further, corneas with limbal stem cell deficiency were less dichroic than controls. Conclusions: These results suggest that rabbit models of limbal stem cell deficiency must be rigorously screened for use in preclinical studies to ensure experimental homogeneity because protocols used to create limbal stem cell deficiency could be not associated with good intra-laboratory reproducibility of clinical features. Limbal stem cell deficiency, as induced herein, altered the optical anisotropic properties of the corneal stroma. Such alterations are indicative of changes in collagen packing and the spatial orientation of glycosaminoglycan chains from proteoglycans. Knowledge of these changes is important to potentiate strategies aimed at restoring the morphofunctional integrity of the corneal stroma affected by limbal stem cell deficiency.

RESUMO Objetivos: Investigar a reprodutibilidade intra-la­boratorial dos fenótipos clínicos e avaliar anisotropias ópticas em córneas de coelhos com deficiência de células tronco limbais. Métodos: Lesões ao limbo foram feitas no olho direito de 23 coelhos adultos da Nova Zelândia Branco, usando um protocolo altamente agressivo, que envolveu peritomia limbal em 360 graus, ceratolimbectomia, cauterização por álcali, e remoção mecânica de epitélio remanescente. Os olhos foram clinicamente avaliados por 28 dias, inclusive por citologia de impressão corneal. As córneas que manifestaram um conjunto de alterações típicas de deficiência de células tronco limbais foram coletadas e submetidas à estudos em histopatologia e em anisotropias ópticas. Córneas saudáveis foram usadas como controles. Diferenças de caminho óptico de birrefringência relacionada à organização do colágeno estromal, e dicroísmo linear relacionado à expressão e à orientação das cadeias de glicosaminoglicanos dos proteoglicanos estromais, foram quantificados por microscopia de luz polarizada. Resultados: Um olho apresentou hipópio e foi excluído do estudo. Todos os olhos estudados (n=22) apresentaram sinais de inflamação ocular. A citologia de impressão não detectou células caliciformes na superfície corneal. Doze de 22 córneas manifestaram alterações clínicas típicas de deficiência de células tronco limbais, caracterizado por defeitos epiteliais, infiltrados inflamatórios, opacidade de moderada à severa, e neovascularização. Estudos por microscopia de luz polarizada mostraram que a deficiência de células tronco limbais aumentou a diferenças de caminho óptico corneal em 24,4% (versus controles). As cór­neas com deficiência de células tronco limbais foram menos dicroicas do que as córneas controle. Conclusões: Coelhos com deficiência de células tronco limbais, para aplicações em estudos pré-clínicos, devem ser rigorosamente selecionados para assegurar homogeneidade experimental, pois há evidências de que protocolos utilizados para indução de deficiência de células tronco limbais não estão associados com boa reprodutibilidade intra-laboratorial de fenótipos clínicos. A deficiência de células tronco limbais, como induzida aqui, alterou as propriedades ópticas anisotrópicas do estroma corneal. Tais alterações são indicativas de mudanças no empacotamento de colágeno e na orientação das cadeias de glicosaminoglicanos dos proteoglicanos. Conhecimentos nessas alterações são importantes para potencializar estratégias que visam a restabelecer a integridade morfofuncional do estromal corneal acometido pela deficiência de células tronco limbais.

Differential diagnosis of periapical cyst using collagen birefringence pattern of the cyst wall

OBJECTIVES: Periapical lesions, including periapical cyst (PC), periapical granuloma (PG), and periapical abscess (PA), are frequently affected by chemical/physical damage during root canal treatment or severe bacterial infection, and thus, the differential diagnosis of periapical lesions may be difficult due to the presence of severe inflammatory reaction. The aim of this study was to make differential diagnosis among PC, PG, and PA under polarizing microscope. MATERIALS AND METHODS: The collagen birefringence patterns of 319 cases of PC (n = 122), PG (n = 158), and PA (n = 39) obtained using a polarizing microscope were compared. In addition, 6 cases of periodontal fibroma (PF) were used as positive controls. RESULTS: Collagen birefringence was condensed with a thick, linear band-like pattern in PC, but was short and irregularly scattered in PG, and scarce or absent in PA. PF showed intense collagen birefringence with a short, palisading pattern but no continuous band-like pattern. The linear band-like birefringence in PC was ascribed to pre-existing expansile tensile stress of the cyst wall. CONCLUSIONS: In this study all PCs (n = 122) were distinguishable from PGs and PAs by their characteristic birefringence, despite the absence of lining epithelium (n = 20). Therefore, the authors suggest that the presence of linear band-like collagen birefringence of the cyst wall aids the diagnostic differentiation of PC from PG and PA.

Efeito da aplicação do ultrassom terapêutico durante 4 e 5 minutos por área do transdutor no processo de reparação de tendão de ratos / Effect of application times 3, 4 and 5 minutes ERA of therapeutic ultrasound in tendon injury of calcaneal rats

O objetivo deste estudo foi avaliar o efeito dos tempos de aplicação 3, 4 e 5 minutos por ERA do ultrassom terapêutico (UST) na organização das fibras de colágeno em lesão do tendão do calcâneo de ratos. Foram utilizados quarenta ratos machos Wistar, dos quais 32 sofreram tenotomia total do tendão do calcâneo e foram divididos em 5 grupos: GC, sem tenotomia e tratamento; GT, com tenotomia e sem tratamento; UST3, UST4 e UST5 submetidos à tenotomia e tratados com UST nos tempos de 3, 4 e 5 minutos por área de radiação efetiva respectivamente. Os animais foram submetidos à primeira aplicação do UST foi 24 horas após a cirurgia de tenotomia. A irradiação ultrassônica foi aplicada com os seguintes parâmetros: 1 MHz, modo pulsado com 20% do ciclo de trabalho (2 ms de emissão / 8 ms de intervalo), frequência de 100 Hz, 0,5 W / cm² de intensidade e ERA de 0,5 cm². A aplicação foi realizada 1x/dia. Os animais foram sacrificados após a 10ª sessão de tratamento, no 12º dia pós-operatório. Os tendões foram retirados cirurgicamente para análise da organização das fibras colágenas através do método de birrefringência (retardo óptico - OR). As fibras colágenas mostraram melhor agregação e organização no grupo UST3, UST4 e UST5 quando comparado ao GT (p<0.05) e o UST5 apresentou melhor resposta na comparação intergrupos. Conclui-se que o UST, aplicado no tempo de 5 minutos por área de radiação efetiva, apresentou a melhor dose-resposta quanto à organização das fibras colágenas no reparo tecidual de tendões de ratos...

The aim of this study was to evaluate the effect of application times 3, 4 and 5 minutes ERA of therapeutic ultrasound in the organization of the collagen fibers in rat calcaneal tendon injury. Forty male Wistar rats were used, of which 32 underwent complete tenotomy of the calcaneal tendon and were divided into 5 groups: GC without tenotomy and treatment; GT tenotomy with and without treatment; UST3, UST4 UST5 and submitted to tenotomy treated with therapeutic ultrasound at times 3, 4 and 5 minutes per effective radiating area respectively. The animals were submitted to the first application of therapy US tenotomy 24 hours after surgery. Ultrasonic irradiation was applied with the following parameters: 1 MHz, pulsed mode at 20% duty cycle (2ms transmission / 8 ms interval), frequency 100 Hz, 0.5 W / cm² intensity and ERA 0.5 cm². The application was performed 1x / day. The animals were sacrificed after the 10th treatment session, on the 12th postoperative day. The tendons were surgically removed for analysis of the organization of the collagen fibers through birefringence method (optical delay - OR). The collagen fibers showed better aggregation and organization in group UST3, UST4 and UST5 when compared to the GT (p <0.05) and UST5 showed better response in the intergroup comparison. We conclude that the UST, applied in time of 5 minutes for effective radiation area, presented the best dose-response as the organization of the collagen fibers in tissue repair of rat tendons...

Stromal characterization and comparison of odontogenic cysts and odontogenic tumors using picrosirius red stain and polarizing microscopy: A retrospective and histochemical study.

INTRODUCTION: Odontogenic lesions represent a range of conditions, the features of which probably depend on the stage of induction towards tooth formation reached prior to neoplastic or hamartomatous proliferation. It has been also suggested that inductive changes may allow progression from one type of odontogenic tumor to another. The epithelium also plays an important role in the pathogenesis of these lesions; even stroma is likely to play an equally important role in the pathogenesis and biological behavior. So, this study was performed to investigate, compare, and correlate different types of collagen fibers in odontogenic cysts and odontogenic tumors. MATERIALS AND METHODS: Thirty each pre‑diagnosed odontogenic cysts and tumors were histochemically analyzed using a special stain (Picrosirius red stain) and polarizing microscopy. RESULTS: Seven cases (99%) of inflammatory cysts exhibited predominantly greenish‑yellow birefringence indicating procollagen, intermediate, or pathologic collagen fibers suggestive of loosely packed collagen fibers. Predominant yellowish‑orange birefringence exhibited by 21 cases (99%) of developmental cysts was comparable to the yellowish‑orange and orangish‑red to red birefringence exhibited by odontogenic tumors suggesting tightly packed fibers. CONCLUSIONS: The Picrosirius red stain in conjunction with polarizing microscopy serves as a specific and sensitive tool in characterizing collagen fibers in odontogenic cysts and odontogenic tumor.

Temperature Sensor By Using Selectively Filled Photonic Crystal Fiber Sagnac Interferometer.

This paper reviews the application of a selectively filled photonic crystal fiber to construct sagnac interferometer (OFSI) based temperature sensor. The transmission of the OFSI is in sinusoidal form and dependent on temperature. A higher sensitivity is obtained by selective filling as compare to non selective filling, the sensitivity depends on infiltration length ratio.

Cutaneous amyloidosis at the site of insulin injection with coexistence of acanthosis nigricans.

Skin is one of the important organs affected by amyloidosis which is characterized by extracellular deposition of fibrillary proteins having homogenous, eosinophilic on routine staining with distinct tinctorial properties. Nodular cutaneous amyloidosis is rare and may affect dermis, subcutis and also vascular walls. Nodular amyloid deposits in the deeper dermis occurring at the site of insulin injection are a rare observation, which is described here. This description indicates that cutaneous amyloidosis may be associated with local subcutaneous injections of insulin and may clinically mimic a neoplasm or lipodystrophic lesion.

Influencia de un enjuague a base de fluoruro y xilitol en la remineralización in vitro del esmalte en dientes temporales / Influence exerted by a xylitol and fluoride based mouthwash on the in vitro enamel remineralization of primary teeth

El propósito del estudio fue evaluar la eficacia de un enjuague bucal con fluoruro de sodio y xilitol, en la remineralización del esmalte de dientes temporales. Se utilizaron 40 dientes sin caries, aplicando ácido fosfórico al 35% durante 20 segundos, y fueron inmersos en el enjuague por 0, 15, 30, 45 y 60 días. Se observaron cortes longitudinales de 150-250 µm de cada muestra y se valoró la remineralización, de acuerdo a la birrefringencia observada después de aplicarles solución de Thoulet (1.47 IR) bajo luz polarizada en un fotomicroscopio. A los 15 días tuvo una media de 0.444 (± 0.527), a los 30 días de 0.778 (± 0.441), a los 45 de 1.444 (± 0.527) y a los 60 días de 1.47 (± 0.483). El análisis de varianza permitió establecer diferencias estadísticamente significativas entre los grupos (p < 0.001), y comparándolos entre sí (p < 0.05). Puede concluirse que el enjuague empleado tuvo un ligero efecto remineralizante en el esmalte.

The purpose of the present study was to assess the effectiveness on primary teeth of a fluoride and xylitol based mouthwash. 40 caries-free teeth were used. 35% phosphoric acid was applied during 20 seconds. Teeth were then immersed in the mouthwash for 0, 15, 30, 45 and 60 days. 150-250μm longitudinal slices were taken of each sample. Re-mineralization was assessed according to bi-refringence observed after applying Thoulet solution (1.47 IR). Assessment was conducted under polarized light in a photo-microscope. At 15 days, a mean of 0.444 (± 0.527) was observed. After 30 days the observed mean was 0.778 (± 0.441). At 45 days, observed mean was 1.444 (± 0.527), and at 60 days, observed mean was 1.47 (± 0.483). Variance analysis established statistically significant differences among groups (p < 0.001) as well as when comparisons among groups were established (p < 0.05). After conducting the aforementioned tests it could be concluded that the employed mouthwash exerted a slight re-mineralizing effect upon the enamel of treated teeth.

Primary cutaneous amyloidosis: A clinico-pathological study with emphasis on polarized microscopy.

Background: Primary localized cutaneous amyloidosis (PCA) is a relatively rare condition characterized by amyloid deposition in dermis without systemic involvement. Although, histopathological examination of the lesion reveals amorphous eosinophilic deposits in papillary dermis examination of congo red stained slides under polarized light will give definitive diagnosis Aims: To study the clinicopathological features of cutaneous amyloidosis emphasizing the utility of polarized light in diagnosis. Materials and Methods : A clinicopathological study of primary cutaneous amyloidosis over a period of 8 years was undertaken. All the cases, clinically diagnosed and histopathologically proven as cutaneous amyloidosis were stained with congo red and studied under polarized light. Results and Conclusions: Of the 45 cases of clinically suspected amyloidosis, 32 cases were proven histopathologically as primary cutaneous amyloidosis and confirmed by congo red stain under polarized light which showed apple green birefringence. Among the two types of PCA, lichen amyloidosis was the most common variant accounting to 65.63% with pure cases of macular amyloidosis accounting for only 15.63%. Biphasic amyloidosis was seen in 18.75%. Knee was the commonest site of involvement with pruritis being the most common symptom. Histopathologically, the most common findings were hyperkeratosis, irregular acanthosis and expansion of dermal papillae by amyloid deposits showing apple green birefringence under polarized microscope with congo red staining. Although, H and E stain gives a clue for the diagnosis of amyloid nevertheless congo red staining under polarized light forms a very sensitive and definitive method for confirmation.

Identificación de colágeno I y III con picrosirius red/ polarización en el estroma de tumores salivales / Identification of type I and III collagen by picrosirius red/polarization of tumoral salivary stroma

El estroma juega un rol importante en los procesos tumorales de invasión y metástasis. Las fibras de colágeno tipo I son el principal componente estructural del estroma en distintos tumores. Sin embargo, hay muy pocos estudios en los tumores de glándulas salivales. Basándonos en estos antecedentes el objetivo de la presente comunicación fue estudiar las características del colágeno con Picrosirius red/polarización en tumores benignos y malignos de glándulas salivales para evaluar su posible rol en los mecanismos de progresión tumoral. Cortes histológicos de adenoma pleomórfico, carcinoma adenoide quístico y carcinoma epitelial mioepitelial se colorearon con H/E y Picrosirius red y se examinaron con microscopio de polarización. La birrefringencia del colágeno con Picrosirius/polarización resultó diferente en el estroma de los tumores malignos (carcinoma adenoide quístico y carcinoma epitelial mioepitelial), con predominio de colágeno I, en comparación con el tumor benigno (adenoma pleomórfico), con predominio de colágeno III. El diferente perfil de coloración en las fibras colágenas producidas en el estroma de los tumores analizados podría relacionarse con diferentes mecanismos de expansión tumoral, los que fueron poco estudiados en los tumores de glándulas salivales. Más estudios son necesarios para obtener resultados más concluyentes que contribuyan al diagnóstico, pronóstico y tratamiento.

The stroma plays an important rol in tumoral invasion and metastasis. Type I collagen is the main structural component of the stroma in several tumors. However, there are few studies on salivary gland tumors. Based on this background the objective of the present communication was to study collagen characteristics with picrosirius red/polarization on malignant and benign tumors of salivary glands to evaluate its posible rol in the tumoral progression mechanism. Histological sections of pleomorphic adenoma, adenoid cystic carcinoma and epithelial/myoepithelial carcinoma were stained with H/E and picrosirius red and were studied with polarization microscope. Collagen birefringence with Picrosirius/polarization was different in the malignant tumor stroma (adenoid cystic carcinoma and epithelialmyoepithelial carcinoma), with predominance of type I collagen, compared with a benign tumor (pleomorphic adenoma), with predominance of type III collagen. The different staining profile in collagen fibers produced in the benign and malignant stroma tumors analized could be related with different tumoral expansion mechanism, which were scarce studied on the salivary glands tumors. More studies are needed to obtain more conclusive results to contribute to diagnosis, prognosis and treatment.

Effect of cataract surgery on retinal nerve fiber layer thickness parameters using scanning laser polarimetry (GDxVCC).

Purpose: To study the effect of cataract extraction on the retinal nerve fiber layer (RNFL) thickness, and assessment by scanning laser polarimetry (SLP), with variable corneal compensation (GDx VCC), at the glaucoma service of a tertiary care center in North India. Materials and Methods: Thirty-two eyes of 32 subjects were enrolled in the study. The subjects underwent RNFL analysis by SLP (GDx VCC) before undergoing phacoemulsification cataract extraction with intraocular lens (IOL) implantation (Acrysof SA 60 AT) four weeks following cataract surgery. The RNFL thickness parameters evaluated both before and after surgery included temporal, superior, nasal, inferior, temporal (TSNIT) average, superior average, inferior average, and nerve fiber index (NFI). Results: The mean age of subjects was 57.6 ± 11.7 years (18 males, 14 females). Mean TSNIT average thickness (μm) pre- and post-cataract surgery was 49.2 ± 14.1 and 56.5 ± 7.6 (P = 0.001). There was a statistically significant increase in RNFL thickness parameters (TSNIT average, superior average, and inferior average) and decrease in NFI post-cataract surgery as compared to the baseline values. Mean NFI pre- and post-cataract surgery was 41.3 ± 15.3 and 21.6 ± 11.8 (P = 0.001). Conclusions: Measurement of RNFL thickness parameters by scanning laser polarimetry is significantly altered following cataract surgery. Post the cataract surgery, a new baseline needs to be established for assessing the longitudinal follow-up of a glaucoma patient. The presence of cataract may lead to an underestimation of the RNFL thickness, and this should be taken into account when analyzing progression in a glaucoma patient.

Influência de diferentes comprimentos de onda da laserterapia de baixa intensidade na regeneração tendínea do rato após tenotomia / Influence of different low-intensity laser therapy wavelengths for rat tendon regeneration following tenotomy

OBJETIVO: Comparar a influência da terapia laser baixa intensidade (TLBI) na organização das fibras de colágeno, na dose de 3J/cm² em dois comprimentos de onda (lambda) (670nm e 904nm) e na associação de ambos, durante o reparo do tendão calcâneo de ratos. MÉTODO Foram utilizadas 37 ratas da raça Wistar divididas em 5 grupos, submetidas a tenotomia total por meio de cisalhamento transversal do tendão na porção média entre a inserção calcânea e a junção miotendínea, com exceção do grupo GP (n= 6) que não houve lesão. O grupo GA (n= 8) foi submetido à irradiação laser lambda= 904nm, diodo de GaAs, emissão pulsada, duração do pulso de 180ns, freqüência de pulso de 2000Hz e potência de pico de 15W e dose de 3J/cm². O grupo GB (n= 8) foi submetido à irradiação laser lambda= 670nm, diodo de AlGaInP, emissão contínua, potência 30mW e dose de 3J/cm². O grupo GAB (n= 8) recebeu irradiação de ambos os lasers 670nm e 904nm associados. O grupo GCL (n= 7) foi submetido a um tratamento placebo, assim como um grupo padrão. Após um total de 12 sessões de laserterapia, os animais foram submetidos à eutanásia no 14º dia pós-operatório. Após processamento histológico padrão, foi realizada a quantificação do retardo óptico pela birrefringência. RESULTADOS: A análise estatística mostra que todos os grupos irradiados apresentaram valores de retardo óptico maiores quando comparados ao grupo placebo (p= 0,00001), o que indica que apresentaram melhor organização das fibras colágenas ao longo do eixo longitudinal do tendão, evidenciando melhor qualidade no reparo. O grupo GAB foi o que apresentou melhores resultados (p= 0,00001) quando comparado aos demais grupos, excetuando-se o GP, que é o referencial de retardo óptico para esta faixa etária.

OBJECTIVE: The aim of this study was to compare the effect of the low level laser therapy in the organization of the collagen fibers with 3 J/cm² of dose in two wavelengths (670nm and 904nm) and in the combination of both on the tissue repair of the calcaneus tendon. METHODS: We used 37 female Wistar rats divided in 5 groups which had been submitted to the total tenotomy. Group GA (n= 8) was submitted to the laser irradiation in lambda= 904nm, GaAS diode, pulsated emission, peak power 15W and dose of 3J/cm², group GB (n= 8) was submitted to laser irradiation lambda= 670nm AlGaInP diode, continuous emission, power 30 mW and dose 3J/cm², group GAB (n= 8) was submitted to association of both of lasers and group GCL (n= 7) which the calcaneum tendon was submitted to placebo treatment. The group GP (n= 6) was a standard group without lesion and treatment. The animals received 12 sessions of lasertherapy and submitted to euthanasia on 14th day after surgery. The tendons were submitted to histological procedure and were analyzed to evaluate the optic retardation (in nm) for the birefringence measurement. RESULTS: The statistic analysis showed that the irradiated groups have higher values of optic retardation statistically significant than placebo group (p= 0,00001). It indicates that all the treated groups show better organization of collagen fibers in the longitudinal axis of the tendon, evidencing better quality in the tissue repair. The group GAB was that shown best results (p= 0,00001) when compared to another groups.

Discriminating Ability of Scanning Laser Polarimetry with Variable Corneal Compensation in Normal and Glaucomatous Eyes

PURPOSE: We investigated the diagnostic ability of scanning laser polarimetry with variable corneal compensation (GDx VCC) parameters to distinguish glaucomatous eyes with different degrees of visual field abnormality from normal eyes. METHODS: Subjects were divided into a control group (n=47) and an early to moderate glaucoma group (n=100). The latter included 53 early glaucoma patients (mean deviation > -6dB with a Humphrey Field Analyzer). Using a receiver operating characteristic (ROC) curve, the diagnostic power of GDx VCC parameters was analyzed and the correlations between those parameters and Humphrey Field Analyzer (HFA) indices were statistically analyzed. RESULTS: Nerve fiber indicator (NFI) provided the best discriminating ability with the highest area under the ROC curve (AUROC) value for detecting eyes with early to moderate perimetric glaucoma. TSNIT average showed the highest AUROC value for detecting eyes with early perimetric glaucoma. The optimal NFI cut-off value to discriminate between the control group and early to moderate group was 22, offering the best combination of sensitivity (88.0%) and specificity (83.0%). The optimal TSNIT average cut-off value to discriminate between the control group and early glaucoma group was 53.49 micrometer, providing the best combination of sensitivity (84.9%) and specificity (85.1%). Most of the thickness parameters showed higher AUROC values than those of the ratio or modulation parameters. A statistically significant correlation was found between the GDx VCC parameters and HFA indices. CONCLUSIONS: Measurement of the retinal nerve fiber layer (RNFL) by scanning laser polarimetry with variable corneal compensation is useful in discriminating between normal and glaucomatous eyes.

A Case of Vitreous Amyloidosis

PURPOSE: To report a case of vitreous amyloidosis. METHODS: A 51-year old male presented with bilateral floater and decreased visual acuity of 3 months duration. Small white dots attached to the posterior lens surface were observed on slit lamp examination. The vitreous opacity, which connected with the small white dots to the posterior lens surface, were observed on funduscopic examination, and multiple hyperechoic plaques in the vitreous cavity on B-scan. The pars plana vitrectomy was performed. RESULTS: The aspirate of the pars plana vitrectomy was stained with Congo red and observed with light microscope, and polarized light. Electron microscopy was also performed. The vitreous smear stained with Congo red showed greenish dichroism and birefringent nature with polarized light and fine fibrillar nature of amyloid material was noted on electron microscopy. CONCLUSIONS: To our knowledge, this is the first Korean report of vitreous amyloidosis. The authors diagnosed vitreous amyloidosis that developed in a 51-year-old male patient. The diagnosis was confirmed by light microscope, polarized light and electron microscope.