[Sensibilidad foveal en ojos con edema macular diabético con y sin engrosamiento temporal perifoveal]. / Foveal sensitivity in eyes with diabetic macular edema with and without temporal perifoveal thickening.

BACKGROUND: Visual improvement after photocoagulation in focal diabetic macular edema is more frequent when temporal perifoveal area is not affected; functional status before treatment could be worse in eyes with perifoveal temporal thickening. The correlation between visual acuity and foveal sensitivity (usually significant), would allow to compare macular function. OBJECTIVE: To compare the correlation between retinal sensitivity and visual acuity in eyes with diabetic macular edema, with and without temporal perifoveal thickening. METHOD: Non-experimental, retrospective, comparative, cross-sectional study in type 2 diabetics with macular edema. The correlation between foveal sensitivity and visual acuity was compared in eyes without temporal perifoveal thickening (group 1) and eyes with it (group 2). Multiple regression analysis was used to identify the contribution of foveal sensitivity to the changes of visual acuity; other variables were: center point thickness, center field thickness, temporal perifoveal thickness and macular volume. RESULTS: 60 eyes in group 1, 29 eyes in group 2. Mean sensitivity did no differ between groups (30.0 ± 0.59 vs. 28.4 ± 1.05 dB; p = 0.2), but the correlation between sensitivity and visual acuity did it (group 1, rho: -0.41; group 2, rho: -0.25). In group 1, foveal sensitivity was the only explaining variable of the regression model (beta: -0.52), in group 2 no one explaining variable was included and temporal perifoveal thickness had a negative correlation with foveal sensitivity (rho: -0.60). CONCLUSIONS: Temporal perifoveal thickening reduces the correlation between foveal sensitivity and visual acuity in eyes with diabetic macular edema.

OBJETIVO: Comparar la correlación entre la sensibilidad foveal y la agudeza visual en ojos con edema macular diabético, con y sin engrosamiento temporal perifoveal, característica asociada con mala respuesta terapéutica. MÉTODO: Estudio observacional, prospectivo, comparativo, transversal, en diabéticos con edema macular. Se comparó la correlación entre la sensibilidad foveal y la agudeza visual entre ojos sin (grupo 1) y con (grupo 2) engrosamiento temporal perifoveal (Rho de Spearman). Mediante regresión múltiple se determinó la contribución de la sensibilidad a los cambios de agudeza visual. Se evaluaron también los grosores del punto central y temporal perifoveal, y el volumen macular. RESULTADOS: 60 ojos del grupo 1, 29 ojos del grupo 2. El promedio de sensibilidad no difirió entre grupos (30.0 ± 0.59 vs. 28.4 ± 1.05 dB; p = 0.2), pero la correlación entre sensibilidad y agudeza visual sí (grupo 1, rho: −0.41; grupo 2, rho: −0.25). En el grupo 1, la sensibilidad fue la variable explicativa de la agudeza visual (beta: −0.52); en el grupo 2, ninguna variable se incluyó en el modelo y el grosor temporal perifoveal correlacionó inversamente con la sensibilidad (rho: −0.60). CONCLUSIONES: el engrosamiento temporal perifoveal reduce la correlación entre la agudeza visual y la sensibilidad foveal en ojos con edema macular diabético.

Circularity of the foveal avascular zone and its correlation with parafoveal vessel density, in subjects with and without diabetes.

PURPOSE: To characterize the distribution of the foveal avascular zone circularity and its correlation with parafoveal vessel density, in subjects with and without diabetes. METHODS: Observational, descriptive, cross-sectional, and prospective study; subjects without diabetes (Group 1), with diabetes without retinopathy (Group 2), or with diabetic retinopathy (Group 3) were included. Means of foveal avascular zone circularity and parafoveal vessel density were compared between groups (Kruskal-Wallis) and their correlation was calculated with Spearman's Rho test. RESULTS: Seventy-seven eyes; central vessel density mean was higher in Group 1 than in Group 2 and higher in Group 2 than in Group 3; inner and complete vessel density means were also higher in Group 2 than in Group 3. The mean of the foveal avascular zone circularity did not differ between groups, and in Group 3 it had a positive correlation with central (0.45), inner (0.56), and complete (0.53) vessel densities. CONCLUSIONS: Circularity does not differ between subjects with diabetes, with and without retinopathy, and has only a low correlation with parafoveal vessel density in people with diabetic retinopathy, which does not allow anticipating a reduction of vessel density in this disease.

OBJETIVO: Caracterizar la distribución de la circularidad de la zona avascular foveal y su correlación con la densidad vascular perifoveal, en sujetos con y sin diabetes. MÉTODO: Estudio observacional, descriptivo, transversal y prospectivo; se incluyeron sujetos sin diabetes (Grupo 1), con diabetes sin retinopatía (Grupo 2) y con retinopatía diabética (Grupo 3). Los promedios de circularidad de la zona avascular foveal y de la densidad vascular parafoveal se compararon entre grupos (Kruskal-Wallis), y se calculó su correlación mediante la prueba Rho de Spearman. RESULTADOS: Se estudiaron 77 ojos. El promedio de la densidad vascular central fue mayor en el Grupo 1 que en el Grupo 2, y mayor en el Grupo 2 que en el Grupo 3. Los promedios de la densidad vascular interna y completa también fueron mayores en el Grupo 2 que en el Grupo 3. El promedio de la circularidad de la zona avascular foveal no difirió entre grupos, y en el Grupo 3 tuvo una correlación positiva con la densidad vascular central (0.45), interna (0.56) y completa (0.53). CONCLUSIONES: La circularidad no difiere entre sujetos con y sin diabetes, con y sin retinopatía, y solo tiene una baja correlación con la densidad vascular parafoveal en sujetos con retinopatía diabética, lo cual no permite anticipar una reducción de la densidad vascular en esta enfermedad.

Reduction of foveal sensitivity in diabetic macular edema with visual acuity 20/20.

OBJECTIVE: To compare foveal sensitivity in eyes with and without diabetic macular edema, with 20/20 visual acuity. METHODS: Non-experimental, comparative, prospective, cross sectional study in eyes with and without retinopathy and focal macular edema, with 20/20 visual acuity. The sample was divided in 3 groups: (1) non-diabetic subjects, (2) diabetics without retinopathy, and 3) diabetics with non-proliferative retinopathy and clinically significant macular edema. Median foveal sensitivity was compared between groups (Kruskal Wallis test). RESULTS: 86 eyes (28 in group 1, 26 in group 2 and 32 in group (3). Medians shown a statistical difference between groups (p = 0.001). Median foveal sensitivity was significantly lower in group 3 than in group 1 (p = 0.001) and than in group 2 (p = 0.03). Median foveal sensitivity did not differ between groups 1 and 2 (p = 0.10). CONCLUSION: Foveal sensitivity in diabetic macular edema and visual acuity 20/20 is lower in eyes with center sparing clinically significant macular edema and 20/20 visual acuity. The prognostic value of this dysfunction requires evaluation, in order to learn whether early treatment is required in these eyes.

OBJETIVO: Comparar la sensibilidad foveal en ojos con y sin edema macular diabético, con agudeza visual 20/20. MÉTODO: Estudio observacional, comparativo, transversal y prospectivo, en ojos con y sin retinopatía y edema macular focal, con agudeza visual 20/20. La muestra se dividió en tres grupos: 1) sujetos sin diabetes, 2) diabéticos sin retinopatía, y 3) diabéticos con retinopatía diabética no proliferativa y edema macular focal. Se compararon las medianas de la sensibilidad foveal entre grupos mediante la prueba de Kruskal-Wallis. RESULTADOS: Se evaluaron 86 ojos (28 del grupo 1, 26 del 2 y 32 del 3). La comparación de medianas mostró una diferencia significativa entre grupos (p = 0.001). La sensibilidad foveal fue significativamente menor en el grupo 3 que en el grupo 1 (p = 0.001) y que en el grupo 2 (p = 0.03). La mediana de la sensibilidad foveal no difirió entre los grupos 1 y 2 (p = 0.10). CONCLUSIÓN: La sensibilidad foveal en el edema macular diabético con agudeza visual 20/20 es menor en ojos con edema macular clínicamente significativo sin engrosamiento del centro de la mácula y agudeza visual 20/20. Determinar el valor pronóstico de esta disfunción requiere una evaluación adicional para identificar si se necesita tratamiento temprano en estos ojos.

Should the outcome of focal photocoagulation for center-sparing diabetic macular edema require expanding the definition of center involvement?

Photocoagulation may still be a therapeutic choice for center-sparing diabetic macular edema. We compared the visual evolution after photocoagulation, in eyes with focal diabetic macular edema, stratified per the location of thickening with optical coherence tomography. We evaluated people with type 2 diabetes and focal diabetic macular edema, before and three weeks after focal photocoagulation. We divided the sample by edema location: central (group1); paracentral (group 2) and pericentral (group 3) and compared the proportions of eyes with baseline visual impairment, visual improvement, and visual deterioration between groups; central edema was evaluated with logistic regression, as an explaining variable of baseline visual impairment and visual improvement. The study included 160 eyes: 77 in group 1, 20 in group 2, 63 in group 3; baseline visual impairment was more frequent in groups 1 and 2 (52.6%) than in group 3 (28.6%, p = 0.002, OR 2.77) and as common in groups 1 (51.9%) and 2 (55.0%, p = 0.8). The proportions of visual improvement and visual deterioration did not differ between groups (p > 0.05). The outcome after focal photocoagulation was similar in paracentral (considered center-sparing) and central macular edema; the definition of center involvement, which needs intravitreal antiangiogenics, should expand to include paracentral thickening.