Hyperintensities of middle frontal gyrus in patients with diabetic optic neuropathy: a dynamic amplitude of low-frequency fluctuation study.

Diabetic optic neuropathy (DON) is a diverse complication of diabetes and its pathogenesis has not been fully elucidated. The purpose of this study was to explore dynamic cerebral activity changes in DON patients using dynamic amplitude of low-frequency fluctuation (dALFF). In total, 22 DON patients and 22 healthy controls were enrolled. The dALFF approach was used in all participants to investigate dynamic intrinsic brain activity differences between the two groups. Compared with HCs, DON patients exhibited significantly increased dALFF variability in the right middle frontal gyrus (P < 0.01). Conversely, DON patients exhibited obviously decreased dALFF variability in the right precuneus (P < 0.01). We also found that there were significant negative correlations between HADS scores and dALFF values of the right middle frontal gyrus in the DON patients (r = -0.6404, P <0.01 for anxiety and r = -0.6346, P <0.01 for depression; HADS, Hospital Anxiety and Depression Scale). Abnormal variability of dALFF was observed in specific areas of the cerebrum in DON patients, which may contribute to distinguishing patients with DON from HCs and a better understanding of DON, hyperintensities of right middle frontal gyrus may be potential diagnostic marker for DON.

White Matter Hyperintensities of Bilateral Lenticular Putamen in Patients with Proliferative Diabetic Retinopathy: A Voxel-based Morphometric Study.

OBJECTIVE: To explore the changes in gray matter volume (GMV) and white matter volume (WMV) in proliferative diabetic retinopathy (PDR) patients using voxel-based morphometry (VBM). PARTICIPANTS AND METHODS: In total, 15 patients (10 males, 5 females) with PDR were enrolled to the patient group and 15 healthy controls (10 males, 5 females) to the control group, matched for age, sex, handedness, and education status. All individuals underwent voxel-based morphometry scans. GMV and WMV were compared between the two groups. RESULTS: GMV in bilateral superior temporal gyrus, sixth area of left cerebellum, left middle temporal gyrus, left orbital inferior frontal gyrus and left middle cingulum gyrus and WMV in left thalamus and left precuneus were significantly lower in patients than controls (P<0.01). Conversely, WMV was significantly higher in bilateral lenticular putamen of patients than controls (P<0.01). CONCLUSION: Abnormal GMV and WMV in many specific areas of the cerebrum provide new insights for exploration of the occurrence and development of DR and its pathophysiology.

Vitrectomy alone or Vitrectomy Combined with Scleral Buckle in the Management of Giant Retinal Tears.

The aim of this study was to compare as to which treatment achieves better outcomes in the management of giant retinal tears (GRTs) - pars plana vitrectomy (PPV) alone or combined with scleral buckle (SB)? The Web of Science, PubMed, and Cochrane Library databases were searched from January 1, 1950 to October 1, 2020. Pooled odds ratios (ORs), 95% confidence intervals (CIs), heterogeneity, and publication bias were determined with Review Manager software. PPV combined with SB significantly decreased the risk of recurrent retinal detachment (RRD, OR = 0.39, 95% CI = 0.20-0.77, I2 = 35%, p = 0.006) in GRT management compared with PPV alone. However, the final anatomical success (OR = 0.74, 95% CI = 0.23-2.39, I2 = 0%, p = 0.61), final visual acuity (OR = 1.11, 95% CI = 0.48-2.58, I2=13%, p = 0.81), and risk factors of GRT ≥180° (OR = 0.43, 95% CI = 0.15-1.22, I2 = 0%, p = 0.11) were not significantly different between the two approaches. According to the final anatomical success, final visual acuity, and risk factors of GRT ≥180°, there were no significant differences between PPV combined with SB and PPV alone for the management of GRT in the current study, except in decreasing the risk of RRD. Key Words: Giant retinal tear, Pars plana vitrectomy, Scleral buckling, Recurrent retinal detachment.

Effect of intravitreal injection of ranibizumab on retinal ganglion cells and microvessels in the early stage of diabetic retinopathy in rats with streptozotocin-induced diabetes.

The aim of the present study was to investigate the effect of intravitreal injection of ranibizumab on retinal ganglion cells and microvessels at the early stage of diabetic retinopathy (DR) in rats with streptozotocin-induced diabetes mellitus (DM). DM was induced by a single intraperitoneal injection of 60 mg/kg body weight streptozotocin. A total of 80 diabetic rats were randomly assigned to four treatment groups (n=20 in each group) and were treated with an oculus dexter intravitreal injection of ranibizumab. Groups A and B were injected with ranibizumab two and four weeks after DM-induction, respectively, while groups a and b (controls) were injected with phosphate-buffered saline at the same time points. In addition, 20 normal rats were assigned to group N (blank control; without intraocular injection). Vitreous humors were isolated for vascular endothelial growth factor (VEGF)-A ELISA and retinas were obtained for hematoxylin and eosin staining, periodic acid-Schiff staining and fluorescence imaging techniques at six and eight weeks after the onset of DM. At six and eight weeks, a significantly increased in retinal ganglion cells (RGCs) was observed in group A compared with group a (P<0.01), and in group B compared with group b (P<0.01). In addition, there was a significant difference in the RGC level between groups A and B at six weeks after DM induction (P<0.01), but not at eight weeks (P>0.05). VEGF-A concentrations in rat vitreous humors were significantly lower in groups A and B compared with groups a and b at six and eight weeks after DM induction (P<0.01). Furthermore, the ratio of endotheliocytes to pericytes in groups A and B was significantly lower compared with groups a and b at six and eight weeks (P<0.05). Furthermore, it was also demonstrated that type IV collagen-positive strands were not present in group A during the eight-week observation period, which was significantly different from groups a, b and B (P<0.01). In conclusion, intravitreal injection of ranibizumab at a very early stage of DR in streptozotocin-induced DM rats slowed the progression of DR by reducing vascular regression or damage and maintaining RGC numbers, as well as reducing VEGF-A concentrations.