RESUMEN

In this paper, we compare the post-operative macular microvascular parameters (vascular density and foveal avascular zone) in eyes with refractory macular hole (MH) that underwent pars plana vitrectomy and autologous retinal transplant (ART) with the fellow unoperated eye. We conducted a retrospective case control study of six consecutive patients who underwent pars plana vitrectomy and ART with at least six months of post-operative follow-up. Pre-operatively, all eyes underwent SD-OCT (Spectral Domain Optical Coherence Tomography) examination. Post-operative OCT-A analyses included vascular density (VD) and the foveal avascular zone (FAZ) area. Six patients with a mean age of 63.7 ± 14.3 years were included. The mean follow-up was 24 months (range 6-30 months). The pre-operative BCVA (best-corrected visual acuity) was 0.99 ± 0.46 logMAR and 1.02 ± 0.23 logMAR at the last post-operative visit (p = 1.00). The mean MH diameter was 966 ± 620 µm. VD in the MH group was 28.1 ± 7.3% compared to 20.2 ± 2.9% in the fellow eyes group (p < 0.05). The mean post-operative FAZ area in the MH group was 109.8 ± 114.6 mm2 compared to 41.5 ± 10.4 mm2 in the control group (p < 0.05). In all six eyes, MH closure was obtained. The post-operative visual acuity did not improve after ART. Eyes with a closed MH showed a bigger FAZ with a higher VD compared to the fellow healthy eye.

RESUMEN

PURPOSE: Evaluate optical coherence tomography angiography (OCT-A) features in retinal vein occlusions (RVO) associated with visual outcomes after anti-VEGF. METHODS: Analytical observational study performed in eyes with macular edema secondary to RVO treated with anti-VEGF, with at least 6 months of follow-up. Bradley et al. classification of macular ischemia was used. Logistic regression analysis was used to investigate associations between final best-corrected visual acuity (BCVA) and OCT-A. RESULTS: A total of 62 eyes, 61 subjects, mean age of 70 ± 12,6 years were included. Median follow up time 21,2 months (IQR 24.8), 53,2% had central retinal vein occlusion (CRVO) and 46,8% branch retinal vein occlusion (BRVO). Median BCVA pre-treatment was 0,84 logMAR (IQR 0,83) and post-treatment 0,47 logMAR (IQR 0,52). BCVA improved at the end of follow-up (p = 0,01), as well as central retinal thickness (CRT) (p = 0,02). Regarding capillary densities (CD), there was a decrease for both plexus, Superficial CD (p = 0,01) and Deep CD (p = 0,01), being more involved the superficial plexus. The lower the capillary density in both plexus, the worse BCVA, Superficial CD (r - 0,27, p = 0,03) and Deep CD (r - 0,29, p = 0,02). Media FAZ pre-treatment was 0,30 mm2 (IQR 0,23), with enlargement to 0,37 mm2 (IQR 0,32) (p = 0,01) post-treatment. Preservation of External Limiting Membrane/ Ellipsoid Zone (ELM/EZ) was seen in 60% of subjects (n = 37). The majority had grade 3 macular ischemia. Variables that best explain visual results were, baseline visual acuity (p = 0,01), pre-treatment CRT (p = 0,02) and pretreatment foveal superficial CD (p = 0,02). CONCLUSIONS: Variables that best explain final vision after anti-VEGF were baseline visual acuity, CRT and foveal superficial CD.

Asunto(s)

RESUMEN

BACKGROUND: Timely detection of early microvascular changes in patients with prediabetes could help reduce the likelihood of progression of diabetes-related retinal complications. AIM: To determine early microvascular changes in patients with prediabetes using optical coherence tomography angiography (OCT-A). METHODS: In this single-center retrospective case-control study, macular OCT-A images of superficial capillary plexus (SCP) and deep capillary plexus (DCP) were analyzed in non-diabetic controls, and prediabetic and diabetic subjects. A quantitative analysis was performed using ImageJ software of the foveal avascular zone (FAZ) area, acircularity index (AI), perfusion density (PD), and vascular length density (VLD). RESULTS: A total of 94 eyes of 53 patients were included in this study. The global mean age was 57.7 years, 39.6% men and 60.4% women. In SCP, the mean PD was 0.283 ± 0.15, 0.186 ± 0.720, and 0.186 ± 0.07 in non-diabetic controls, and prediabetic and diabetic groups, respectively. The mean VLD was 8.728 ± 3.425 in non-diabetic controls, 6.147 ± 1.399 in prediabetic group, and 6.292 ± 1.997 in patients with diabetes. The comparison of prediabetic patients and controls shows statistical differences between PD and VLD in both plexus SCP (p = 0.002 and p = 0.001, respectively) and DCP (p = 0.005 and p = 0.002, respectively). The mean area of FAZ in patients with diabetes and normal individuals was 0.281 and 0.196 mm2, respectively (p < 0.001). AI was higher in the control group (0.87 ± 0.14) and prediabetic group (0.80 ± 0.17) compared to diabetic patients (0.64 ± 0.19). There were no differences in FAZ area and AI between prediabetic and non-diabetic controls. CONCLUSION: PD and VLD demonstrated to be early microvascular changes in prediabetic patients evaluated by OCT-A. No alterations of FAZ were evidenced in this group.

RESUMEN

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.

Asunto(s)

RESUMEN

BACKGROUND: Parafoveal capillary density changes have not been characterized in type 2 diabetics without retinopathy. OBJECTIVE: To compare parafoveal capillary density between healthy subjects, and diabetics with and without retinopathy. METHOD: Observational, prospective, transversal and comparative study; subjects without diabetes (group 1), diabetics without retinopathy (group 2), with retinopathy (group 3) and with diabetic macular edema (group 4), without macular ischemia, were included. The study variable was parafoveal capillary density, and the predictor variables were the measures of the foveal avascular zone, retinal thickness and the group. The variables were compared between groups using Kruskal-Wallis and Spearman's Rho tests. RESULTS: One hundred and forty eyes were evaluated; parafoveal capillary density was higher in group 1 than in the rest (p < 0.05). Area, perimeter and diameter of the foveal avascular zone were higher in group 3. A positive correlation existed a positive between parafoveal capillary density and central field thickness in groups 1, 2 and 3. CONCLUSION: Parafoveal capillary density decreases as diabetes-induced damage increase; a reduction may exist in diabetics without retinopathy and normal retinal thickness and foveal avascular zone are normal. The clinical impact of this finding requires further evaluation.

ANTECEDENTES: Los cambios de densidad parafoveal no se han caracterizado en diabéticos tipo 2 sin retinopatía. OBJETIVO: Comparar la densidad capilar parafoveal entre sujetos sanos y diabéticos con y sin retinopatía. MÉTODO: Estudio observacional, prospectivo, transversal y comparativo. Se incluyeron sujetos sin diabetes (grupo 1), diabéticos tipo 2 sin y con retinopatía (grupos 2 y 3), y con edema macular (grupo 4), sin isquemia macular. La variable de estudio fue la densidad capilar parafoveal, y las variables predictoras fueron las mediciones de la ZAF, el grosor retiniano y el grupo. Se compararon las diferencias entre grupos mediante las pruebas de Kruskal-Wallis y Rho de Spearman. RESULTADOS: 144 ojos; la densidad capilar parafoveal del grupo 1 superó la de los restantes (p < 0.05). El área, el perímetro y el diámetro de la ZAF fueron mayores en el grupo 3. Existió correlación positiva entre la densidad capilar parafoveal y el grosor del campo central en los grupos 1, 2, y 3. CONCLUSIONES: La densidad capilar parafoveal disminuye conforme avanza el daño por diabetes tipo 2; puede existir una reducción en sujetos con diabetes sin retinopatía, con grosor retiniano y ZAF normales. El impacto clínico de este hallazgo requiere evaluación adicional.

Asunto(s)

RESUMEN

Abstract Introduction A new method for segmenting and quantifying the macular area based on morphological alternating sequential filtering (ASF) is proposed. Previous studies show that persons with diabetes present alterations in the foveal avascular zone (FAZ) prior to the appearance of retinopathy. Thus, a proper characterization of FAZ using a method of automatic classification and prediction is a supportive and complementary tool for medical evaluation of the macular region, and may be useful for possible early treatment of eye diseases in persons without diabetic retinopathy. Methods We obtained high-resolution retinal images using a non-invasive functional imaging system called Retinal Function Imager to generate a series of combined capillary perfusion maps. We filtered sequentially the macular images to reduce the complexity by ASF. Then we segmented the FAZ using watershed transform from an automatic selection of markers. Using Hu's moment invariants as a descriptor, we can automatically classify and categorize each FAZ. Results The FAZ differences between non-diabetic volunteers and diabetic subjects were automatically distinguished by the proposed system with an accuracy of 81%. Conclusion This is an innovative method to classify FAZ using a fully automatic algorithm for segmentation (based on morphological operators) and for the classification (based on descriptor formed by Hu's moments) despite the presence of edema or other structures. This is an alternative tool for eye exams, which may contribute to the analysis and evaluation of FAZ morphology, promoting the prevention of macular impairment in diabetics without retinopathy.