Estudio del epitelio conjuntival de las ampollas filtrantes mediante citología de impresión / Evaluation of conjunctival epithelium of filtering blebs by impression cytology

OBJETIVO: Estudiar la superficie conjuntival de ampollas filtrantes mediante citología de impresión y comparar los resultados con el área de conjuntiva circundante. MÉTODO: Se incluyeron 12 ampollas de 8 pacientes; 4 tras trabeculectomía sin mitomicina C (MMC), 6 tras trabeculectomía con MMC y 2 tras esclerectomía profunda no perforante sin MMC. Se realizaron citologías de impresión conjuntival de las ampollas filtrantes y del área circundante. Se usó una clasificación de 0 a 3 para describir el grado de cohesión de las células epiteliales y la densidad de células caliciformes, siendo el grado 0 indicador de células epiteliales en placas y abundantes células caliciformes y el grado 3, de pérdida de cohesión del epitelio y ausencia de células caliciformes. RESULTADOS: El grado medio de la citología de impresión en las ampollas de filtración fue de 2,4 ± 0,9 y en el área circundante de 0,8 ± 0,3 (p < 0,001). Estas diferencias fueron independientes del uso de MMC (p = 0,48). El 83% de las ampollas presentaban células epiteliales cilíndricas dehiscentes y ausencia de células caliciformes. En la conjuntiva circundante, el 100% de los casos presentaban células epiteliales en placas con distintos grados de células caliciformes. CONCLUSIÓN: El epitelio de las ampollas filtrantes presentó cambios significativos que consistían en aumento de los espacios intercelulares y pérdida de células caliciformes. Estos espacios intercelulares aumentados podrían explicar un paso transcelular del humor acuoso. La pérdida de mucina secundaria a la pérdida de células caliciformes contribuiría al riesgo de infección de las ampollas filtrantes

PURPOSE: To study the ocular surface in filtering blebs using impression cytology, comparing the bleb side and areas outside the bleb edges. METHODS: Twelve filtering blebs of 8 patients were included: 4 cases of trabeculectomy without mitomycin C (MMC), 6 cases of trabeculectomy with MMC, and 2 cases of non-penetrating glaucoma surgery. Impression cytology specimens were taken from filtering blebs as well as outside the bleb area. A classification scale from 0 to 3 was used to describe the distribution of epithelial cells and the density of goblet cells. Grade 0 indicated cohesive epithelial cells and abundant goblet cells; and the grade 3 indicated loss of epithelial cohesion and absence of goblet cells. RESULTS: The mean grade of cytology in filtering blebs was 2.4 ± 0.9, and in the outside bleb area of 0.8 ± 0.3 (P<0.001). These differences were independent of the use of MMC (P=0.48). The large majority (83%) of filtering blebs showed a decrease in epithelial cohesion and absence of goblet cells. Outside the bleb area, 100% of the cases had cohesive epithelial cells with different grades of goblet cells. CONCLUSION: The conjunctival epithelium overlying the filtering blebs showed significant changes that consisted of increased intercellular spaces and loss of goblet cells. These increased intercellular spaces could explain the trans-epithelial pathway of aqueous humor. The least amount of mucin due to loss of goblet cells could contribute to increase the risk of infection in filtering blebs

[Evaluation of conjunctival epithelium of filtering blebs by impression cytology]. / Estudio del epitelio conjuntival de las ampollas filtrantes mediante citología de impresión.

PURPOSE: To study the ocular surface in filtering blebs using impression cytology, comparing the bleb side and areas outside the bleb edges. METHODS: Twelve filtering blebs of 8 patients were included: 4 cases of trabeculectomy without mitomycin C (MMC), 6 cases of trabeculectomy with MMC, and 2 cases of non-penetrating glaucoma surgery. Impression cytology specimens were taken from filtering blebs as well as outside the bleb area. A classification scale from 0 to 3 was used to describe the distribution of epithelial cells and the density of goblet cells. Grade 0 indicated cohesive epithelial cells and abundant goblet cells; and the grade 3 indicated loss of epithelial cohesion and absence of goblet cells. RESULTS: The mean grade of cytology in filtering blebs was 2.4 ± 0.9, and in the outside bleb area of 0.8 ± 0.3 (P<.001). These differences were independent of the use of MMC (P=.48). The large majority (83%) of filtering blebs showed a decrease in epithelial cohesion and absence of goblet cells. Outside the bleb area, 100% of the cases had cohesive epithelial cells with different grades of goblet cells. CONCLUSION: The conjunctival epithelium overlying the filtering blebs showed significant changes that consisted of increased intercellular spaces and loss of goblet cells. These increased intercellular spaces could explain the trans-epithelial pathway of aqueous humor. The least amount of mucin due to loss of goblet cells could contribute to increase the risk of infection in filtering blebs.