Desmascarando o queratocone: efeito do epitélio corneano no queratocone / Unmasking keratoconus: effect of corneal epithelium in keratoconus

Resumo Objetivo: Na presença de uma córnea irregular, como no queratocone, o epitélio tem uma distribuição diferente do normal, "mascarando" a irregularidade do estroma. A avaliação topográfica sem considerar o efeito do epitélio pode induzir uma avaliação menos correta, afetando a precisão de um eventual tratamento guiado por topografia. O objetivo deste trabalho é avaliar o efeito de "máscara" do epitélio no queratocone, comparando a tomografia corneana com e sem epitélio, no decurso da realização de Crosslinking (CXL). Métodos: Cinco olhos de 5 doentes com queratocone em progressão submetidos a CXL segundo o protocolo original de Dresden. Foi realizada tomografia corneana antes e durante o procedimento (imediatamente após a remoção do epitélio), e avaliados os valores da queratometria - K1, K2, K médio (Km), ponto de máxima curvatura (Kmax), valores paquimétricos e astigmatismo corneano. Resultados: Os valores médios de curvatura corneanas antes e após a remoção do epitélio foram de: K1: 43,50 ± 2,54D e 44,32±2,64D (p=0,080); K2: 46,64±2,35D e 49,38±2,86D (p=0,043); Km: 45,48±2,42D e 46,72±2,60D (p=0,042). Observou-se igualmente um aumento estatisticamente significativo do valor de queratometria máxima após a remoção do epitélio (p=0,043). Na paquimetria central observou-se uma redução média de 26,8µm de 524,8±33,0µm para 498,2±37,7µm (p= 0,042). Conclusão: Observou-se um aumento estatisticamente significativo nos valores do Kmax, K2, e Kmédio após remoção do epitélio. Este estudo demonstra o efeito de "máscara" que o epitélio exerce no queratocone.

Abstract Objective: In the presence of an irregular cornea, like in keratoconus, the corneal epithelium has a different profile "masking" the irregular corneal stroma surface. Topographical analysis without considering the epithelium effect can result in an incorrect assessment, affecting the accuracy of any topography guided treatment. The aim of this study was to evaluate the "masking" effect of the corneal epithelium on corneal curvature in patients with keratoconus, comparing topographical findings before and after removal of the epithelium during Crosslinking (CXL). Methods: Five eyes of 5 patients with progressive keratoconus submitted to CXL according to the original Dresden protocol. Corneal topography was performed before and during the procedure (immediately after epithelium removal) and values of keratometry: K1, K2, mean K (Km), maximum corneal apical curvature (Kmax), corneal thickness and corneal astigmatism were evaluated. Results: The average values of corneal curvature before and after epithelial remove were: K1: 43.50±2.54D and 44.32±2,64D (p=0.080); K2 46.64±2,35D and 49.38±2,86D (p=0.043); Km 45.48±2.42D and 46.72±2.60D (p=0.042). It was also observed a significant increase in the maximum values of corneal apical curvature after removal of the epithelium (p=0.043). In central corneal thickness there was seen a reduction of 26.8µm from 524.8±33.0µm to 498.2±37.7µm (p = 0.042). Conclusion: There was seen a significant increase in the values of Kmax, K2 and mean K. This study demonstrates the masking effect of corneal epithelium on corneal curvature in keratoconus.

Ceratoacantoma: aspectos morfológicos, clínicos e cirúrgicos / Keratoacanthoma: morphological, clinical, and surgical aspects

Introdução: O ceratoacantoma é uma neoplasia epitelial de rápido crescimento, mais frequente em áreas de exposição solar. Habitualmente, apresenta-se como lesão única, arredondada, com depressão central preenchida de queratina. As semelhanças clínicas e histopatológicas com o carcinoma de células escamosas, frequentemente, dificultam o diagnóstico diferencial. A biópsia excisional é a abordagem de escolha, permitindo diagnóstico e tratamento. Método: O presente estudo é observacional e retrospectivo, com dados de 162 pacientes tratados de 2005 a 2013, no Hospital Felício Rocho, em Belo Horizonte, MG. Todos os pacientes submeteram-se à excisão cirúrgica dos tumores. Foram estudados: sexo, idade, número de lesões, localização, tamanho do tumor e diagnóstico pré-operatório. Resultados: Dos 162 pacientes, totalizando 173 lesões, 154 (95,06%) apresentavam ceratoacantoma único. Noventa e dois eram do gênero masculino (56,80%) e 70 do feminino (43,20%). A idade dos pacientes variou de 11 a 96 anos, com média de 71,23 anos. As lesões localizavam-se predominantemente nos membros superiores (43,64%), na face (28,48%) e nos membros inferiores (17,58%). Nas hipóteses diagnósticas formuladas pelos cirurgiões, no pedido do exame anatomopatológico, houve diagnóstico correto em 63,13%. Conclusão: O ceratoacantoma é uma neoplasia epitelial de características morfológicas semelhantes ao carcinoma de células escamosas, o que, por muitas vezes, dificulta o diagnóstico. Torna-se necessária, portanto, a excisão cirúrgica completa das lesões suspeitas para diagnóstico e tratamento corretos.

Introduction: Keratoacanthoma is an epithelial neoplasm of rapid growth, more frequent in areas of sun exposure, and usually appears as a single, rounded lesion with a central depression filled with keratin. Clinical and histopathological similarities with squamous cell carcinoma often make differential diagnosis difficult. Excisional biopsy is the approach of choice, allowing diagnosis and treatment. Method: This is an observational and retrospective study, in which data of 162 patients treated at the Hospital Felício Rocho from 2005 to 2013, in Belo Horizonte, MG, were analyzed. All patients underwent surgical excision of tumors. Data on sex, age, number of lesions, location, tumor size, and preoperative diagnosis were studied. Results: Of the 162 patients, with a total of 173 lesions, only 154 (95.06%) had keratoacanthoma. There were 92 male (56.80%) and 70 female (43.20%) patients. The age of patients ranged from 11 to 96 years, with an average of 71.23 years. The lesions were located predominantly in the upper limbs (43.64%), face (28.48%), and lower limbs (17.58%). In the diagnostic hypotheses formulated by surgeons at the request of the pathology, the diagnosis was correct in 63.13%. Conclusion: Keratoacanthoma is an epithelial tumor with morphological characteristics similar to those of squamous cell carcinoma, which often complicates the diagnosis. Therefore, the complete excision of the suspicious lesions is necessary for correct diagnosis and treatment.

Urethroplasty Using Autologous Urethral Tissue-embedded Acellular Porcine Bladder Submucosa Matrix Grafts for the Management of Long-Segment Urethral Stricture in a Rabbit Model

We conducted this study to evaluate the combined effect of acellular bladder submucosa matrix (BSM) and autologous urethral tissue for the treatment of long segment urethral stricture in a rabbit model. To prepare the BSM, porcine bladder submucosa was processed, decellularized, configured into a sheet-like shape, and sterilized. Twenty rabbits were randomized to normal control, urethral stricture, urethroplasty using BSM only or BSM/autologous urethral tissue (n=5 per group). Retrograde urethrography was performed at 4, 8, and 12 weeks postoperatively, and the grafted specimens were harvested at week 12 to evaluate urethral reconstruction through histopathologic and immunohistochemical analysis. The mean urethral width of the control, stricture, BSM, and BSM/autologous urethral tissue groups at week 12 was 10.3+/-0.80, 3.8+/-1.35, 8.8+/-0.84, and 9.1+/-1.14 mm, respectively. The histopathologic study revealed that the BSM/autologous urethral tissue graft had a normal area of urethral lumen, compact muscular layers, complete epithelialization, and progressive infiltration by vessels in the regenerated urethra. In contrast, the BSM grafts revealed keratinized epithelium, abundant collagenized fibrous connective tissue, and were devoid of bundles of circular smooth muscle. Nontransected ventral onlay-augmented urethroplasty using an acellular BSM scaffold combined with an autologous urethral tissue graft represents a feasible procedure for urethral reconstruction.

Urethroplasty Using Autologous Urethral Tissue-embedded Acellular Porcine Bladder Submucosa Matrix Grafts for the Management of Long-Segment Urethral Stricture in a Rabbit Model

We conducted this study to evaluate the combined effect of acellular bladder submucosa matrix (BSM) and autologous urethral tissue for the treatment of long segment urethral stricture in a rabbit model. To prepare the BSM, porcine bladder submucosa was processed, decellularized, configured into a sheet-like shape, and sterilized. Twenty rabbits were randomized to normal control, urethral stricture, urethroplasty using BSM only or BSM/autologous urethral tissue (n=5 per group). Retrograde urethrography was performed at 4, 8, and 12 weeks postoperatively, and the grafted specimens were harvested at week 12 to evaluate urethral reconstruction through histopathologic and immunohistochemical analysis. The mean urethral width of the control, stricture, BSM, and BSM/autologous urethral tissue groups at week 12 was 10.3+/-0.80, 3.8+/-1.35, 8.8+/-0.84, and 9.1+/-1.14 mm, respectively. The histopathologic study revealed that the BSM/autologous urethral tissue graft had a normal area of urethral lumen, compact muscular layers, complete epithelialization, and progressive infiltration by vessels in the regenerated urethra. In contrast, the BSM grafts revealed keratinized epithelium, abundant collagenized fibrous connective tissue, and were devoid of bundles of circular smooth muscle. Nontransected ventral onlay-augmented urethroplasty using an acellular BSM scaffold combined with an autologous urethral tissue graft represents a feasible procedure for urethral reconstruction.

Surgical treatment of melanin-pigmented gingiva; an esthetic approach.

The aim of this clinical article is to review the methods of depigmentation of melanin pigmentation of gingiva and explain scalpel surgical technique for depigmentation of gingiva.