Effect of Systemic Hypertension on Peripapillary RNFL Thickness in Patients With Diabetes Without Diabetic Retinopathy

Impact of systemic hypertension on inner retinal layer thickness and macular microvasculature in patients with diabetic retinopathy

AIM

To investigate the effects of hypertension (HTN) on inner retinal thickness and macular microvasculature in patients with diabetic retinopathy (DR).

METHODS

Subjects were classified into three groups: patients with type 2 diabetes mellitus (T2DM) (T2DM group), patients with DR (DR-HTN group), and patients with DR and HTN (DR + HTN group). The ganglion cell complex (GCC) thicknesses and the macular vessel density (VD) were compared. Linear regression analyses were performed to identify factors associated with the VD in the DR + HTN group.

RESULTS

The mean GCC thicknesses were 112.2 ± 12.3, 109.2 ± 13.7, and 106.2 ± 11.2 μm in the T2DM, DR-HTN, and DR + HTN groups, respectively (P = 0.045). The mean VDs were 25.4 ± 5.0, 24.3 ± 8.9, and 21.2 ± 7.1% (P = 0.014) for the superficial capillary plexus (SCP) and 25.9 ± 4.3, 22.9 ± 8.5, and 20.2 ± 6.6% (P < 0.001) for the deep capillary plexus (DCP) in the T2DM, DR-HTN, and DR + HTN groups, respectively. In multivariate analyses, the duration of HTN was a significant factor associated with the VD of both SCP (B = -0.24, P = 0.010) and DCP (B = -0.21, P = 0.016).

CONCLUSIONS

Patients with both DR and HTN had a thinner GCC and lower VDs of SCP and DCP than those with DR alone. These outcomes could be associated with the synergistic ischemic effects in DR patients with HTN. Moreover, the duration of HTN in DR patients was significantly associated with macular VD in both SCP and DCP.

Impact of hypertension on changes in peripapillary retinal nerve fiber layer thickness in type 2 diabetes patients

To determine longitudinal changes in the peripapillary retinal nerve fiber layer (pRNFL) thickness in type 2 diabetes mellitus (T2DM) patients with hypertension (HTN). Participants were divided into three groups: normal controls (Group 1), patients with T2DM (Group 2), and patients with both T2DM and HTN (Group 3). Following the initial examination, patients underwent three additional examinations at 1-year intervals. Linear mixed models were used to identify significant changes in pRNFL thickness over time. The baseline mean pRNFL thickness was 95.4 ± 7.9, 93.6 ± 7.8, and 90.7 ± 10.1 μm in Group 1, Group 2, and Group 3, respectively, (P = 0.046). The reduction rate for mean pRNFL thickness was - 0.15 μm/y in Group 1, - 0.54 μm/y in Group 2, and - 1.06 μm/y in Group 3, respectively (P = 0.026). In Group 2, T2DM duration (estimate = - 0.63, P = 0.002) was a significant factor associated with changes in pRNFL thickness in multivariate analysis. In Group 3, HTN duration (estimate = - 0.59, P = 0.036) and HbA1c levels (estimate = - 4.44, P = 0.019) were significantly associated with pRNFL changes. Under ischemic conditions caused by HTN, pRNFL damage due to diabetic retinal neurodegeneration is considered to be more severe. In such patients, the duration of ischemic damage caused by HTN appears to have a significant impact on pRNFL damage, and stricter blood glucose level control could help reduce pRNFL damage.

Diagnosis of cognitive impairment and dementia: blood plasma and optical coherence tomography

Accurate and early diagnosis of Alzheimer's disease and vascular dementia is crucial for enabling timely interventions and improving patient outcomes. This study evaluates the diagnostic performance of plasma biomarkers (neurofilament light chain and phosphorylated tau181) and retinal biomarkers (retinal nerve fibre layer and ganglion cell-inner plexiform layer), individually and in combination, in differentiating moderate cognitive impairment and dementia from mild cognitive impairment and no cognitive impairment. A cross-sectional study was conducted involving 509 participants, aged 50 and older, recruited from a memory clinic. The participants were categorized as normal (n = 100), mild cognitive impairment (n = 144), moderate cognitive impairment (n = 90) or dementia (n = 175) based on detailed clinical assessments, neuropsychological testing and MRI scans. The thickness of the ganglion cell-inner plexiform layer (P < 0.001) and retinal nerve fibre layer (P = 0.030) decreased progressively from normal cognition to cognitive impairment and dementia. The thickest layers were observed in individuals with no cognitive impairment (mean ± standard deviation: ganglion cell-inner plexiform layer: 76 ± 11 µm, retinal nerve fibre layer: 92 ± 10 µm), while the thinnest layers were found in individuals with dementia (ganglion cell-inner plexiform layer: 72 ± 14 µm, retinal nerve fibre layer: 89 ± 12 µm). Plasma biomarker levels increased progressively from normal cognition to cognitive impairment and dementia (P < 0.001). Levels were lowest in individuals with no cognitive impairment [median (interquartile range): neurofilament light chain: 15 (9) pg/mL, phosphorylated tau181: 1.85 (1.00) pg/mL] and highest in those with dementia [neurofilament light chain: 34 (27) pg/mL, phosphorylated tau181: 3.24 (2.81) pg/mL]. After adjusting for retinal scan signal strength, neurofilament light chain showed a stronger negative association with retinal nerve fibre layer thickness [standardized beta estimate (β) = -0.184] and ganglion cell-inner plexiform layer thickness (β = -0.139) compared to phosphorylated tau181, which exhibited weaker associations with ganglion cell-inner plexiform layer (β = -0.091) and retinal nerve fibre layer (β = -0.059). While retinal parameters provided modest discriminatory ability (AUC = 0.60), plasma biomarkers demonstrated superior diagnostic performance (AUC = 0.76). Notably, neurofilament light chain had a stronger association with retinal thinning than phosphorylated tau181 and offered superior diagnostic value for identifying moderate cognitive decline. These findings underscore the potential of plasma biomarkers, particularly neurofilament light chain, for the early detection of dementia.

A cross-sectional study on the impact of hemodialysis duration on retinal nerve fiber layer thinning in hemodialysis patients

This study aimed to investigate the relationship between hemodialysis duration (HDD) and retinal nerve fiber layer (RNFL) thickness. A total of 60 patients receiving maintenance hemodialysis and 67 healthy controls were analyzed. Spectral domain optical coherence tomography (SD-OCT) was employed to measure annular RNFL thicknesses. The hemodialysis group exhibited reduced temporal and inferior RNFL thicknesses relative to the control group. In hemodialysis patients, the inferior RNFL thickness was negatively correlated with HDD and positively correlated with intraocular pressure (IOP). Moreover, IOP was positively correlated with HDD. Mediation analysis showed that the negative correlation between HDD and inferior RNFL thickness was mediated by IOP. In conclusion, hemodialysis leads to temporal and inferior RNFL thinning, and the thickness reduction is proportional to hemodialysis duration. However, such changes are not induced by an increase in IOP.

Prediction of the Cause of Glaucoma Disease Identified by Glaucoma Optical Coherence Tomography Test in Relation to Diabetes and Hypertension at a National Hospital in Seoul: A Retrospective Study

Glaucoma remains the primary cause of long-term blindness. While diabetes mellitus (DM) and hypertension (HTN) are known to influence glaucoma, other factors such as age and sex may be involved. In this retrospective study, we aimed to investigate the associations between age, sex, DM, HTN, and glaucoma risk. We employed optical coherence tomography (OCT) conducted using a 200 × 200-pixel optic cube (Cirrus HD OCT 6000, version 10.0; Carl Zeiss Meditec, Dublin, CA, USA). Effects obscured by low-test signals were disregarded. Data were amassed from 1337 patients. Among them, 218 and 402 patients had DM and HTN, respectively, with 133 (10%) exhibiting both. A sex-based comparison revealed slightly greater retinal nerve fiber layer (RNFL) and ganglion cell-inner plexiform layer (GCIPL) thickness in females. Patients without DM and HTN were predominantly in their 50 s and 60 s, whereas DM and HTN were most prevalent in those in their 60 s and 70 s. Both RNFL and GCIPL thicknesses decreased with advancing age in most patients. The study revealed that older individuals were more prone to glaucoma than younger individuals, with a higher incidence among patients with DM and HTN and reduced RNFL and GCIPL thicknesses. Furthermore, early detection before advancing age could furnish valuable preventive insights.

Retinal neurodegeneration in diabetic retinopathy with systemic hypertension

PURPOSE

To identify the impact of hypertension (HTN) on inner retinal layer thickness in patients with diabetic retinopathy (DR).

METHODS

In this retrospective cross-sectional study, participants were divided into three groups: type 2 diabetes patients without DR (DM group), patients with DR (DR group), and patients with both DR and HTN (DR+HTN group). The peripapillary retinal nerve fiber layer (pRNFL) and ganglion cell-inner plexiform layer (GC-IPL) thicknesses, measured using optical coherence tomography, were compared among the groups.

RESULTS

A total of 470 eyes were enrolled: 224 eyes in the DM group, 131 eyes in the DR group, and 115 eyes in the DR+HTN group. The mean RNFL thicknesses were 95.0 ± 7.7, 92.5 ± 10.1, and 89.2 ± 11.2 μm, and the mean GC-IPL thicknesses were 84.0 ± 5.7, 82.0 ± 7.6, and 79.2 ± 8.1 μm in each group, respectively (all P < 0.001). In the DR+HTN group, the DR stage showed a significant association with pRNFL (B = - 5.38, P = 0.014) and GC-IPL (B = - 5.18, P = 0.001) thicknesses in multivariate analyses. Subgroup analyses revealed that pRNFL (P = 0.007) and GC-IPL (P = 0.005) thicknesses decreased significantly as DR progressed only in the DR+HTN group.

CONCLUSIONS

Patients with both DR and HTN exhibited much thinner pRNFL and GC-IPL, compared with patients with DR only. These results may have been related to the amplified diabetic retinal neurodegeneration and synergistic impact of ischemia in DR patients with concurrent HTN. Additionally, the progression of DR resulted in more severe inner retinal damage when combined with HTN.

Segregation of neuronal and vascular retinal damage in patients with hypertension and diabetes

This study aimed to examine the impact of diabetes and hypertension on retinal nerve fiber layer (RNFL) thickness components. Optical coherence tomography (OCT) measurements do not consider blood vessel contribution, which this study addressed. We hypothesized that diabetes and/or hypertension would lead to thinner RNFL versus controls due to the vascular component. OCT angiography was used to measure the RNFL in 121 controls, 50 diabetes patients, 371 hypertension patients, and 177 diabetes patients with hypertension. A novel technique separated the RNFL thickness into original (vascular component) and corrected (no vascular component) measurements. Diabetes-only (98 ± 1.7 µm; p = 0.002) and diabetes with hypertension (99 ± 0.8 µm; p = 0.001) patients had thinner original RNFL versus controls (102 ± 0.8 µm). No difference was seen between hypertension-only patients (101 ± 0.5 µm; p = 0.083) and controls. After removing the blood vessel component, diabetes/hypertension groups had thinner corrected RNFL versus controls (p = 0.024). Discrepancies in diabetes/hypertension patients were due to thicker retinal blood vessels within the RNFL thickness (p = 0.002). Our findings suggest that diabetes and/or hypertension independently contribute to neurodegenerative thinning of the RNFL, even in the absence of retinopathy. The differentiation of neuronal and vascular components in RNFL thickness measurements provided by the novel technique highlights the importance of considering vascular changes in individuals with these conditions.

Changes in peripapillary microvasculature in patients with type 2 diabetes patients: effect of systemic hypertension

To determine the effect of hypertension (HTN) on the peripapillary microvasculature in type 2 diabetes mellitus (T2DM) patients without diabetic retinopathy (DR). The patients were classified into three groups: the control group (group 1), T2DM group (group 2), and both T2DM and HTN group (group 3). Peripapillary vessel density (VD) was compared using analysis of covariance and linear regression analysis was performed to identify the factors affecting the peripapillary VD. A total of 286 eyes were enrolled: 124 in group 1, 111 in group 2, and 51 in group 3. The peripapillary VDs for the full area were 18.3 ± 0.6, 17.8 ± 1.0, and 17.3 ± 1.2 mm-1 in group 1, group 2, and group 3, respectively, which were significantly different after adjustment for age and best-corrected visual acuity (P < 0.001). In post hoc analyses, group 1 versus group 2 (P < 0.001), group 1 versus group 3 (P < 0.001), and group 2 versus group 3 (P = 0.001) showed significant differences. In linear regression analysis, HTN (B =  - 0.352, P = 0.043) and peripapillary retinal nerve fiber layer (pRNFL) thickness (B = 0.045, P < 0.001) were significantly associated with peripapillary VD in T2DM patients. Peripapillary VD in T2DM patients without clinical DR were lower compared to normal controls, and they were more decreased when HTN was comorbid. The combination of ischemic damage by high blood pressure and impairment of the neurovascular unit by hyperglycemia would result in more severe deterioration of peripapillary microvasculature, and this impairment could be also reflected by pRNFL thinning.

Effect of myopia on the progression of normal tension glaucoma

PURPOSE

Identify risk factors of progression in treated normal-tension glaucoma (NTG) in highly myopic and non-highly myopic eyes.

METHODS

This retrospective, observational case series study included 42 highly myopic glaucoma (HMG, <-6D) eyes and 39 non-highly myopic glaucoma (NHG,≧-6D) eyes. Glaucoma progression was determined by serial visual field data. Univariate and multivariate logistic regression method were used to detect associations between potential risk factors and glaucoma progression.

RESULTS

Among 81 eyes from 81 normal-tension glaucoma patients (mean follow-up, 3.10 years), 20 of 42 eye (45.24%) in the HMG and 14 of 39 eyes (35.90%) in the NHG showed progression. The HMG group had larger optic disc tilt ratio (p = 0.007) and thinner inferior macular thickness (P = 0.03) than the NHG group. Changes in the linear regression values for MD for each group were as follows: -0.652 dB/year for the HMG and -0.717 dB/year for the NHG (P = 0.298). Basal pattern standard deviation (PSD) (OR: 1.55, p = 0.016) and post treatment IOP (OR = 1.54, p = 0.043) were risk factors for visual field progression in normal tension glaucoma patients. In subgroup analysis of HMG patients, PSD (OR: 2.77, p = 0.017) was a risk factor for visual field progression.

CONCLUSION

Reduction IOP was postulated to be contributing in the prevention of visual field progression, especially in highly myopic NTG patients with large basal pattern standard deviation.

Effects of Blood Pressure and Arterial Stiffness on Retinal Neurodegeneration: Cross-Sectional and Longitudinal Evidence From UK Biobank and Chinese Cohorts

BACKGROUND

Hypertension might be a modifiable risk factor for neurodegeneration diseases. However, the associations between blood pressure (BP), arterial stiffness index and retinal neurodegeneration remain unclear.

METHODS

This study used cross-sectional data from the United Kingdom BioBank (UKB) and longitudinal data from the Chinese Ocular Imaging Project (COIP). The macular ganglion cell-inner plexiform layer thickness (mGCIPLT) and macular retinal nerve fiber layer thickness were measured using spectral domain optical coherence tomography imaging. Swept-source optical coherence tomography was performed to obtain the longitudinal trajectory of the mGCIPLT and peripapillary retinal nerve fiber layer thickness in the COIP cohort. Multivariable linear models were used to analyze the associations between BP and retinal measurements.

RESULTS

In a cross-sectional analysis of 22 801 participants from UKB, thinner mGCIPLT was related to higher systolic BP (β: -0.103 [-0.146 to -0.061]; P<0.001), and higher diastolic BP (β: -0.191 [-0.265 to -0.117]; P<0.001), and was significantly associated with higher mean arterial pressure (β: -0.174 [-0.238 to -0.109]; P<0.001) and higher mean pulse pressure (β: -0.080 [-0.139 to -0.020]; P=009). In a longitudinal analysis of 2012 eligible COIP participants, higher levels of baseline systolic BP, diastolic BP, mean arterial pressure, and mean pulse pressure were associated with faster thinning in mGCIPLT and peripapillary retinal nerve fiber layer thickness (all P<0.001). The strongest association was the effect of mean arterial pressure on mGCIPLT (β: -0.118 [-0.175 to -0.061]; P<0.001). The results of the analysis of macular retinal nerve fiber layer thickness and peripapillary retinal nerve fiber layer thickness were consistent with those of mGCIPLT.

CONCLUSIONS

BP levels were independently and consistently associated with various retinal neurodegenerative exacerbations.

HDAC3 Inhibition Alleviates High-Glucose-Induced Retinal Ganglion Cell Death through Inhibiting Inflammasome Activation

Purpose

The exact effects of histone deacetylase 3 (HDAC3) inhibition in DR related retinal ganglion cells (RGCs) death remained unclear. This study is aimed at detecting the influence of HDAC3 on the high-glucose-induced retinal ganglion cell death.

Methods

The retinal HDAC3 expression in DR of different time points was analyzed by immunohistochemical assay and western blot. Besides, the expression of HDAC3 and both retinal thickness and RGC loss were analyzed. The effects of HDAC3 inhibitor on cell viability, oxidative stress, and apoptosis in high-glucose- (HG-) treated RGCs were analyzed. Both inflammatory and antioxidative factors were detected by ELISA.

Results

Advanced effects of HDAC3 inhibition on the expression of NLRP3 inflammasome were detected using western blots. High HDAC3 expression was detected only in the late DR mice (4 months of diabetes duration) but not early DR mice (2 months of diabetes duration). The immunohistochemical assay showed that HDAC3 expression was correlated with both retinal thickness and RCG contents. HDAC3 inhibitor significantly protected the HG-treated RGCs from damaged cell viability, severe apoptosis, and oxidative stress. Advanced pathway analyses showed that HDAC3 inhibition inactivated NLRP3 inflammasome and thus alleviated retinal inflammation. Conclusion. In conclusion, HDAC3 was involved in RGC loss and thus promoted the progression of neurodegeneration of DR. Besides, HDAC3 inhibitor demonstrated protective effects in neurodegeneration in DR through downregulation of NLRP3 activity. The effects of HDAC3 inhibitor in DR management should be confirmed in clinical trials.

Changes in and the association of retinal blood perfusion and retinal nerves in diabetic patients without retinopathy

OBJECTIVE

To explore intraretinal blood flow perfusion and nerve changes, as well as the correlation between them, in diabetic patients without diabetic retinopathy (NDR).

METHOD

Eighty-six NDR patients (86 eyes) who attended the ophthalmology clinic between December 2019 and December 2021 were included. Sixty-four eyes of 64 healthy examined controls in the same period were selected as the control group. The patients underwent routine ophthalmological examination, optical coherence tomography (OCT) and OCT angiography.

RESULTS

The average thickness, minimum thickness and thickness of each quadrant except for the superior temporal quadrant of the ganglion cell-inner plexiform layer (GCIPL) in the macular area of the affected eyes in the NDR group were lower than that of the tested eyes in the control group (P < 0.05). The average retinal nerve fibre layer (RNFL) thickness of the NDR group and the superior, inferior and nasal quadrants around the optic disc of the affected eyes in the NDR group were lower compared with the tested eyes in the control group (P < 0.001, P = 0.003, P = 0.001, P = 0.009). The mean vessel length density in the parafoveal and perifoveal areas in the NDR group was positively associated with the mean GCIPL thickness in the macular area (ρ = 0.265, ρ = 0.257 and P < 0.001). No blood flow perfusion parameters in the NDR group were correlated with the RNFL thickness of the corresponding quadrant around the optic disc (P > 0.05).

CONCLUSION

In diabetic patients without diabetic retinopathy, the superficial retinal vessel density in the macular area positively correlated with GCIPL thickness, and the superficial retinal vessel density around the optic disc was not correlated with RNFL thickness.