Longitudinal Changes in the Peripapillary Retinal Nerve Fiber Layer Thickness in Hypertension: 4-Year Prospective Observational Study

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.

Differences in structural parameters in patients with open-angle glaucoma, high myopia and both diseases concurrently. A pilot study

PURPOSE

To evaluate the differences in structural parameters in patients with open-angle glaucoma (OAG), high myopia (M), and both diseases (OAG-M) concurrently.

METHODS

42 subjects with OAG (n = 14), M (n = 14) and OAG-M (n = 14) were included in a prospective pilot study. Mean peripapillary retinal nerve fiber layer (RNFL) thickness, RNFL in superior, temporal, inferior, nasal quadrants, macular ganglion cell complex (GCC) and its' layers, vessel density (VD) of optic nerve head (ONH) and macula were evaluated.

RESULTS

The OAG-M group showed significantly lowest thickness of mean peripapillary RNFL 89 (49-103) μm (p = 0.021), temporal quadrant 64.5 (51-109) μm (p = 0.001) and inferior quadrant 107 (64-124) μm (p = 0.025). The macular RNFL was thinnest in the OAG-M group (p <0.001). Macular VD in inferior quadrant was lowest in OAG-M group at superficial capillary plexus 45.92 (40.39-51.72) % (p = 0.014) and choriocapillaris 51.62 (49.87-56.63) % (p = 0.035). The lowest ONH VD of temporal quadrant was found in the OAG-M group 52.15 (35.73-59.53) % (p = 0.001) in the superficial capillary plexus. Similarly, the lowest VD of inferior quadrant was found in OAG-M group in the choriocapillaris 54.42 (46.31-64.64) % (p<0.001).

CONCLUSIONS

The M group showed the least thinning in the peripapillary RNFL thickness in the temporal quadrant and macular RNFL compared to other two groups. The highest macular VD in the inferior quadrant was in the M group in the superficial capillary plexus, deep capillary plexus and choriocapillaris. The M group showed highest VD in the temporal quadrant and in total VD of ONH at the superficial capillary plexus and in total VD of ONH at the deep capillary plexus.

PRACTICAL RECOMMENDATIONS

The observed decrease in peripapillary RNFL thickness of the temporal quadrant, macular RNFL thickness, the decrease of macular VD at the inferior quadrant and decrease in VD of the ONH temporal quadrant in deep capillary plexus could be beneficial for diagnosing glaucoma in high myopia.

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.

Retinal nerve fiber layer thinning as a novel fingerprint for cardiovascular events: results from the prospective cohorts in UK and China

BACKGROUND

Retinal structural abnormalities have been found to serve as biomarkers for cardiovascular disease (CVD). However, the association between retinal nerve fiber layer (RNFL) thickness and the incidence of CVD events remains inconclusive, and relevant longitudinal studies are lacking. Therefore, we aimed to examine this link in two prospective cohort studies.

METHODS

A total of 25,563 participants from UK Biobank who were initially free of CVD were included in the current study. Another 635 participants without retinopathy at baseline from the Chinese Guangzhou Diabetes Eye Study (GDES) were adopted as the validation set. Measurements of RNFL thickness in the macular (UK Biobank) and peripapillary (GDES) regions were obtained from optical coherence tomography (OCT). Adjusted hazard ratios (HRs), odd ratios (ORs), and 95% confidence intervals (CI) were calculated to quantify CVD risk.

RESULTS

Over a median follow-up period of 7.67 years, 1281 (5.01%) participants in UK Biobank developed CVD events. Each 5-μm decrease in macular RNFL thickness was associated with an 8% increase in incident CVD risk (HR = 1.08, 95% CI: 1.01-1.17, p = 0.033). Compared with participants in the highest tertile of RNFL thickness, the risk of incident CVD was significantly increased in participants in the lowest thickness tertile (HR = 1.18, 95% CI: 1.01-1.38, p = 0.036). In GDES, 29 (4.57%) patients developed CVD events within 3 years. Lower average peripapillary RNFL thickness was also associated with a higher CVD risk (OR = 1.35, 95% CI: 1.11-1.65, p = 0.003). The additive net reclassification improvement (NRI) was 21.8%, and the absolute NRI was 2.0% by addition of RNFL thickness over the Framingham risk score. Of 29 patients with incident CVD, 7 were correctly reclassified to a higher risk category while 1 was reclassified to a lower category, and 21 high risk patients were not reclassified.

CONCLUSIONS

RNFL thinning was independently associated with increased incident cardiovascular risk and improved reclassification capability, indicating RNFL thickness derived from the non-invasive OCT as a potential retinal fingerprint for CVD event across ethnicities and health conditions.

TRIAL REGISTRATION

ISRCTN 15853192.

Co-occurrence of chronic kidney disease and glaucoma: Epidemiology and etiological mechanisms

As the histology, physiology, and pathophysiology of eyes and kidneys show substantial overlap, it has been suggested that eye and kidney diseases, such as glaucoma and chronic kidney disease (CKD), may be closely interlinked. We review the relationship between CKD and various subtypes of glaucoma, including primary open-angle glaucoma, primary angle- closure glaucoma, normal tension glaucoma, pseudoexfoliation syndrome, and several glaucoma endophenotypes. We also discuss the underlying pathogenic mechanisms and common risk factors for CKD and glaucoma, including atherosclerosis, the renin-angiotensin system, genes and genetic polymorphisms, vitamin D deficiency, and erythropoietin. The prevalence of glaucoma appears elevated in CKD patients, and vice versa, and the literature points to many intriguing associations; however, the associations are not always confirmed, and sometimes apparently opposite observations are reported. Glaucoma and CKD are complex diseases, and their mutual influence is only partially understood.

Superficial capillary plexus vessel density/deep capillary plexus vessel density ratio in healthy eyes

BACKGROUND

To identify factors differently affecting the superficial capillary plexus (SCP) and deep capillary plexus (DCP) in healthy eyes using their vessel density (VD) ratio.

METHODS

Healthy eyes were enrolled. The ratio between the VD of SCP and DCP (SVD/DVD ratio) was calculated. Pearson correlation analyses were performed to identify the relationships between this ratio and other factors.

RESULTS

The mean SVD and DVD were 36.2 ± 5.7 and 37.7 ± 4.9%, respectively, and the mean SVD/DVD ratio was 0.96 ± 0.15. The SVD was significantly correlated with the best-corrected visual acuity (BCVA) (r = - 0.368, P <  0.001), age (r = - 0.408, P <  0.001), and OCTA quality (r = 0.520, P <  0.001). The DVD was significantly correlated with the BCVA (r = - 0.150, P = 0.008), age (r = - 0.229, P <  0.001), and OCTA quality (r = 0.555, P <  0.001). Among various factors, age (r = - 0.296, P <  0.001), the BCVA (r = - 0.237, P <  0.001), axial length (r = 0.234, P <  0.001), and OCTA quality (r = 0.270, P < 0.001) were significantly correlated with the SVD/DVD ratio.

CONCLUSIONS

Age, BCVA, axial length, and OCTA image quality were significantly correlated with the SVD/DVD ratio. Age, the BCVA, and OCTA quality were more strongly correlated with the SCP, and the axial length was more strongly correlated with the DCP.

Accelerated Peripapillary Retinal Nerve Fiber Layer Degeneration in Patients With Chronic Kidney Disease: A 2-Year Longitudinal Study

Purpose

To evaluate the longitudinal changes in the peripapillary retinal nerve fiber layer (pRNFL) in patients with chronic kidney disease (CKD).

Methods

In this prospective cohort study, the CKD group consisted of patients with CKD stage ≥ 3. Age-matched healthy controls were enrolled at a 1:4 ratio. Spectral-domain optical coherence tomography was used to measure the pRNFL at baseline, 1 year, and 2 years. Within-group longitudinal changes and between-group comparisons were performed using linear mixed models.

Results

Overall, 152 patients with CKD and 40 controls were included (mean ages, 62.8 ± 9.1 years vs. 63.0 ± 9.3 years; P = 0.931). The CKD group showed faster loss of pRNFL than the control group (-0.87 µm/y vs. -0.26 µm/y; P = 0.004). Subgroup analysis found that the rate of pRNFL change was -0.41 µm/y in stage 3a CKD, -0.74 µm/y in stage 3b, -0.98 µm/y in stage 4/5, and -1.38 µm/y in end-stage renal disease. Multiple linear regression analysis revealed that CKD stage (coefficient = -0.549; 95% confidence interval [CI], -0.966 to -0.131; P = 0.010), hypertension (coefficient = -1.557; 95% CI -3.013 to -0.101; P = 0.036), and rim area (coefficient = -1.505; 95% CI, -2.940 to -0.070; P = 0.040) were factors associated with the pRNFL change over 2 years.

Conclusions

Patients with CKD experienced faster pRNFL loss than healthy controls did. Severity of CKD, hypertension, and rim area were independent factors associated with the loss of pRNFL.

Translational Relevance

This study contributes to our understanding of retinal neurodegeneration in normal aging and in patients with chronic kidney diseases.

Different characteristics of retinal damage between chronic hypertension and hypertensive retinopathy

The purpose of this study was to identify how chronic hypertension (HTN) and hypertensive retinopathy (HTNR) have different effects on retinal damage including inner retinal thinning and microvasculature impairment. The subjects were divided into three groups: controls, HTN patients without HTNR (HTN group), and patients with relieved HTNR (HTNR group). The ganglion cell-inner plexiform layer (GC-IPL) thickness, vessel density (VD), and GC-IPL/VD ratio were compared among the groups. A total of 241 eyes were enrolled; 101 in the control group, 92 in the HTN group, and 48 in the HTNR group. The mean GC-IPL thicknesses were 83.5 ± 5.7, 82.1 ± 6.2, and 75.9 ± 10.7 μm in each group, respectively (P < 0.001). The VD was 20.5 ± 1.3, 19.6 ± 1.4, and 19.5 ± 1.6 mm^-1 in each group, respectively (P = 0.001). The GC-IPL/VD ratio was 4.10 ± 0.33, 4.20 ± 0.40, and 3.88 ± 0.56 in each group, respectively (P < 0.001). In the HTNR group, HTN duration (B = 0.054, P = 0.013) and systolic blood pressure (SBP) (B = -0.012, P = 0.004) were significantly associated with the GC-IPL/VD ratio. In conclusion, inner retinal reduction and retinal microvasculature impairment were observed in patients with HTN and HTNR, and the GC-IPL/VD ratio of HTNR patients was significantly lower than that of HTN patients, indicating more prominent damage to the inner retina than microvasculature in HTNR patients. Additionally, the GC-IPL/VD ratio was significantly associated with SBP in HTNR patients, so more strict BP control is required in HTNR patients.

The Weiss Ring, a Major Confounding Factor For Measurements of Peripapillary Retinal Nerve Fiber Layer Thickness: Short title: The Impact of the Weiss Ring On RNFL Thickness Measurements

PURPOSE

To identify how the Weiss ring affects the measurement of mean and sectoral peripapillary retinal nerve fiber layer (pRNFL) thicknesses.

DESIGN

Retrospective, cross-sectional study.

METHODS

Subjects were divided into two groups: controls (control group) and subjects in which a Weiss ring was visible on optical coherence tomography fundus images (WR group). Mean and sectoral pRNFL thicknesses were compared between the two groups.

RESULTS

A total of 205 eyes were enrolled: 131 eyes in the control group and 74 eyes in the WR group. The mean pRNFL thicknesses of the control group and WR group were 97.2 ± 6.7 µm and 94.6 ± 10.8 µm, respectively (P = .042). In sectoral thickness, the inferior sector of the WR group was 112.1 ± 23.2 µm, which was significantly thinner than that of the control group (125.5 ± 13.3 µm; P < .001). The Weiss ring was located in 10 eyes (13.5%) in the superior sector, 7 eyes (9.5%) in the temporal sector, 40 eyes (54.1%) in the inferior sector, and 17 eyes (23.0%) in the nasal sector. In analyses of reproducibility, the coefficient of variation and intraclass coefficient of the inferior sector measurement were 10.90% and 0.409, respectively, indicating low reliability of the measurement.

CONCLUSIONS

Eyes with a Weiss ring showed thinner mean and inferior pRNFL thicknesses than normal controls, which would be a measurement error caused by the Weiss ring. This could be a major confounding factor for analyses of pRNFL changes, especially in glaucoma patients.

Associations of statin use with the onset and progression of open-angle glaucoma: A systematic review and meta-analysis

BACKGROUND

Statins, the first-line therapy for hyperlipidemia, have received considerable attention as candidates for glaucoma treatments given its neuroprotective effects. In this systematic review and meta-analysis, we intended to assess the association of statin use with the onset and progression of open-angle glaucoma (OAG).

METHODS

Databases including PubMed, Embase and Web of Science Core Collection were searched for longitudinal studies reporting the association between statin use and OAG onset or progression on Feb 3, 2021. A meta-analysis was performed for the association between statin use and OAG onset. Relative risks (RRs) with 95% confidential intervals (CIs) were retrieved from included studies and pooled using random-effects models. Potential risks of bias were evaluated by the Newcastle-Ottawa Quality Assessment Scale for all eligible studies. This study had been registered on PROSPERO (CRD 42021232172).

FINDINGS

515,788 participants (mean age 68.7 years, 62.3% female) from ten studies were included in the systematic review of the association between statin use and OAG onset, and 26,347 OAG patients (mean age 67.3 years, 52.2% female) from seven studies were included for the association between statin use and OAG progression. Potential risks of bias were detected in 12 studies, which were mainly attributed to selection and confounding bias. In addition, 515,600 participants from eight studies were included in the meta-analysis which collectively showed that statin use was associated with a reduced risk of OAG onset (Pooled RR: 0.95; 95%CI: 0.93-0.98; I²=0.199;). No significant heterogeneity or publication bias was found for studies included in the meta-analysis. There were inconsistent evidences for the association between statin use and OAG progression.

INTERPRETATION

Statin use is associated with a slightly lower risk of OAG onset based on existing evidences from longitudinal observational studies, the association between statin use and OAG progression remains inconclusive. The included evidences were typically weak due to poor study design and under-powered studies. Current findings should be interpreted cautiously and still need to be validated in further research.

FUNDING

The National Key R&D Program of China (2018YFC0116500), Science and Technology Planning Project of Guangdong Province (2013B20400003), the China Postdoctoral Science Foundation (2019TQ0365), the National Natural Science Foundation of China (82000901 and 82101171).

Association of Neuroretinal Thinning and Microvascular Changes with Hypertension in an Older Population in Southern Italy

Background: Retinal microvasculature assessment at capillary level may potentially aid the evaluation of early microvascular changes due to hypertension. We aimed to investigate associations between the measures obtained using optical coherence tomography (OCT) and OCT-angiography (OCT-A) and hypertension, in a southern Italian older population. Methods: We performed a cross-sectional analysis from a population-based study on 731 participants aged 65 years+ subdivided into two groups according to the presence or absence of blood hypertension without hypertensive retinopathy. The average thickness of the ganglion cell complex (GCC) and the retinal nerve fiber layer (RNFL) were measured. The foveal avascular zone area, vascular density (VD) at the macular site and of the optic nerve head (ONH) and radial peripapillary capillary (RPC) plexi were evaluated. Logistic regression was applied to assess the association of ocular measurements with hypertension. Results: GCC thickness was inversely associated with hypertension (odds ratio (OR): 0.98, 95% confidence interval (CI): 0.97–1). A rarefaction of VD of the ONH plexus at the inferior temporal sector (OR: 0.95, 95% CI: 0.91–0.99) and, conversely, a higher VD of the ONH and RPC plexi inside optic disc (OR: 1.07, 95% CI: 1.04–1.10; OR: 1.04, 95% CI: 1.02–1.06, respectively) were significantly associated with hypertension. Conclusion: A neuroretinal thinning involving GCC and a change in capillary density at the peripapillary network were related to the hypertension in older patients without hypertensive retinopathy. Assessing peripapillary retinal microvasculature using OCT-A may be a useful non-invasive approach to detect early microvascular changes due to hypertension.

Retinal nerve fibre layer/ganglion cell-inner plexiform layer thickness ratio in patients with systemic hypertension

PURPOSE

Acute and chronic hypertension may have different pathophysiological mechanisms in the retina. Here, we compared the retinal nerve fibre layer (RNFL)/ganglion cell-inner plexiform layer (GC-IPL) thickness ratios of patients with 'relieved' severe hypertensive retinopathy (relieved HTNR) and chronic hypertension without retinopathy (chronic HTN) to those of normal controls.

METHODS

We performed cross-sectional study. The eyes were divided into the following groups: normal controls (Group A, age ≥50 years; Group D, age <50 years); chronic HTN (Group B, <10 years of HTN; TNHT; Group C, ≥10 years of HTN); and relieved HTNR (previously diagnosed with grade IV HTNR and relieved retinopathy for >1 year; Group E), and the RNFL/GC-IPL thickness ratio was compared among Groups A-C and between Groups D and E.

RESULTS

A total of 379 eyes were included in this study. Groups A-E consisted of 145, 59, 63, 60 and 52 eyes, respectively. The RNFL/GC-IPL thickness ratios were 1.161 ± 0.093, 1.158 ± 0.082 and 1.162 ± 0.089 in groups A-C, respectively, and did not showed a statistically difference (p = 0.966). The RNFL/GC-IPL thickness ratio of groups D and E were 1.169 ± 0.080 and 1.221 ± 0.080, respectively, and showed a statistically difference (p = 0.001).

CONCLUSIONS

The RNFL/GC-IPL thickness ratios of the chronic HTN group did not show a difference compared with the normal controls. However, relieved HTNR patients showed a higher ratio than the normal controls. Physicians should be aware that acute hypertensive injury could affect the RNFL/GC-IPL thickness ratio.

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

Type 2 diabetes mellitus (T2DM) and hypertension (HTN) are both relatively common systemic diseases and cause damage to the retina, such as inner retina reduction and microvascular impairment. The purpose of this study was to identify peripapillary retinal nerve fiber layer (pRNFL) damage by diabetic neurodegeneration and the effects of HTN on the pRNFL thickness in patients with T2DM without clinical diabetic retinopathy. Subjects were divided into three groups: healthy control subjects (group 1), patients with T2DM (group 2), and patients with both diabetes and HTN (group 3). The pRNFL thickness was measured using optical coherence tomography and compared among each group. Linear regression analyses were performed to identify factors associated with pRNFL thickness. A total of 325 eyes were included: 143 eyes in the group 1, 126 eyes in group 2, and 56 eyes in group 3. The mean pRNFL thicknesses of each group were 96.1 ± 7.7, 94.4 ± 8.6, and 91.6 ± 9.6 μm, respectively (P = 0.003). In multivariate linear analyses, diabetes duration (β = -0.236; P = 0.018) and HTN (β = -3.766; P = 0.008) were significant factors affecting the pRNFL thickness in groups 2 and 3. Additionally, the HTN duration was significantly correlated with pRNFL thickness in group 3 (R ² = 0.121; P = 0.008). In conclusion, patients with T2DM with HTN showed thinner pRNFL thickness than those with T2DM only. Additionally, the duration of HTN was significantly correlated with pRNFL thickness in patients with both diabetes and HTN.

Impacts of Systemic Hypertension on the Macular Microvasculature in Diabetic Patients Without Clinical Diabetic Retinopathy

Purpose

To identify the impact of hypertension (HTN) on macular microvasculature in type 2 diabetes (T2DM) patients without clinical diabetic retinopathy.

Methods

In this retrospective cross-sectional study, subjects were divided into three groups: controls (control group), patients with T2DM (DM group), and patients with both T2DM and HTN (DM + HTN group). The vessel length density (VD) was compared among the groups. Linear regression analyses were performed to identify factors associated with VD.

Results

The VD in the control, DM, and DM + HTN groups was 20.43 ± 1.16, 19.50 ± 1.45, and 18.19 ± 2.06 mm⁻¹, respectively (P < 0.001). The best-corrected visual acuity (B = −9.30; P = 0.002), duration of T2DM (B = −0.04; P = 0.020), HTN (B = −0.51; P = 0.016), signal strength (B = 1.12; P < 0.001), and ganglion cell–inner plexiform layer thickness (B = 0.06; P < 0.001) were significant factors affecting VD in patients with T2DM. Additionally, the hemoglobin A1c (HbA1c) (B = −0.49; P = 0.016) was significantly associated with VD in patients with both T2DM and HTN.

Conclusions

Patients with T2DM had impaired macular microvasculature, and patients with T2DM with HTN exhibited greater impairment of the microvasculature than did patients with T2DM only. Additionally, physicians should be aware that the macular microvasculature would be more vulnerable to hyperglycemic damage under ischemic conditions by HTN.

Association of high myopia with peripapillary retinal nerve fiber layer in patients with hypertension

Purpose

To identify the impacts of hypertension (HTN), high myopia, and the combination thereof on peripapillary retinal nerve fiber layer (pRNFL) thickness.

Methods

All subjects were divided into four groups: control (group 1); patients with HTN without high myopia (group 2); patients with high myopia without HTN (group 3); and patients with both HTN and high myopia (group 4). The pRNFL thicknesses were compared using a one-way analysis of variance. Univariate and multivariate linear regression analyses were used to identify factors affecting pRNFL thickness in subjects with and without HTN.

Results

The mean pRNFL thicknesses were 93.9±8.8, 88.7±6.8, 86.4±8.1, and 82.5±9.6 μm in group 1, 2, 3, and 4, respectively, and differed significantly (P<0.001). On multivariate linear regression analyses, age (β = -0.181, P = 0.044), axial length (β = -1.491, P<0.001), and HTN (β = -4.876, P = 0.044) significantly affected pRNFL thickness. Additionally, age and axial length affected the pRNFL thickness in subjects with HTN (age, β = -0.254, P = 0.020; axial length, β = -1.608, P<0.001) much more than in subjects without HTN (age, β = -0.028, P = 0.712; axial length, β = -1.324, P<0.001).

Conclusions

High myopia and HTN affected pRNFL reduction and a combination of the 2 diseases exacerbated pRNFL damage. This could be a confounding factor in interpreting pRNFL thickness in patients with ophthalmic diseases affecting the pRNFL thickness when combined with the 2 diseases.

Effects of prolonged type 2 diabetes on changes in peripapillary retinal nerve fiber layer thickness in diabetic eyes without clinical diabetic retinopathy

To identify the effects of prolonged type 2 diabetes (T2DM) on changes in peripapillary retinal nerve fiber layer (pRNFL) thickness in patients without clinical diabetic retinopathy. Subjects were divided into two groups: controls and patients with T2DM (DM group). After the initial visits, the pRNFL thicknesses were measured three more times at 1-year intervals. Subgroup analyses were performed in patients with T2DM duration ≥ 10 years. The mean pRNFL thickness at each visit was 95.8 ± 8.1, 95.4 ± 8.3, 94.9 ± 8.1, and 94.5 ± 8.3 μm in the control group (P = 0.138) (n = 55); and 93.4 ± 9.1, 92.1 ± 9.3, 90.9 ± 9.3, and 89.5 ± 9.2 μm in the DM group (P < 0.001) (n = 85). The estimated rate of reduction in mean pRNFL thickness was - 0.45 μm/year in the control group and - 1.34 μm/year in the DM group, respectively. In the DM group, the BCVA and HbA1c (both P = 0.001) were significant factors associated with pRNFL reduction. In patients with T2DM duration ≥ 10 years, the estimated pRNFL reduction rate was - 1.61 μm/year, and hypertension was a significant factor affecting the pRNFL reduction (P = 0.046). We confirmed rapid pRNFL reduction over time in T2DM, and the reduction rate was higher in patients with T2DM ≥ 10 years. Additionally, BCVA and HbA1c levels were significantly associated with the change in pRNFL thickness in T2DM patients.

Association of Myopia with Peripapillary Retinal Nerve Fiber Layer Thickness in Diabetic Patients Without Diabetic Retinopathy

Purpose

To investigate the association between myopia and peripapillary retinal nerve fiber layer (pRNFL) thickness in diabetic patients without diabetic retinopathy (DR).

Methods

A total of 271 eyes of 271 participants were included. They were divided into four groups according to the presence of myopia (≤ -3 diopters [D]) and diabetes without DR: (1) control group (n = 76), (2) myopia group (n = 57), (3) diabetes group (n = 82), and (4) diabetes + myopia group (n = 56). The peripapillary average and sector RNFL thicknesses were measured and compared among the four groups to determine the effects of myopia and diabetes. Covariates were adjusted using analyses of covariance. Linear regression analyses were fitted to evaluate the factors associated with pRNFL.

Results

Spherical equivalents were 0.12 ± 1.31 D in the control group, -4.00 ± 1.47 D in the myopia group, 0.00 ± 1.05 D in the diabetes group, and -4.33 ± 1.70 D in the diabetes + myopia group (P < 0.001). The respective axial lengths (ALs) were 23.91 ± 0.99 mm, 25.16 ± 0.94 mm, 23.68 ± 0.77 mm, and 25.34 ± 1.33 mm (P < 0.001). The average pRNFL showed a progressive decrease from the control group (97.16 ± 8.73 µm) to the myopia group (94.04 ± 9.13 µm) to the diabetes group (93.33 ± 9.07 µm) to the diabetes + myopia group (91.25 ± 9.72 µm) (P = 0.009). Age, diabetes, hypertension, and AL were significantly correlated with the pRNFL. The rate of reduction of pRNFL with increasing age was higher in the diabetes + myopia group than in the other groups, and pRNFL in the diabetes groups decreased more steeply with increasing AL compared to the non-diabetic groups.

Conclusions

Myopia and diabetes are important factors affecting pRNFL thickness, and the simultaneous presence of diabetes and myopia results in greater pRNFL damage than observed with either pathology alone.

Retinal Neurovascular Impairment in Patients with Essential Hypertension: An Optical Coherence Tomography Angiography Study

Purpose

To investigate retinal neurovascular structural changes in patients with essential hypertension.

Methods

This observational cross-sectional study consisted of 199 right eyes from 169 nondiabetic essential hypertensive patients, divided into groups as follows: group A, 113 patients with hypertensive retinopathy (HTNR); group B, 56 patients without HTNR; and a control group of 30 healthy subjects. Peripapillary retinal nerve fiber layer (RNFL), radial peripapillary segmented (RPC), ganglion cell–inner plexiform layer (GC-IPL), and superficial (SVP) and deep (DVP) vascular plexus density at the macula (6 × 6 mm²) were measured by optical coherence tomography angiography (OCTA).

Results

DVP density was significantly reduced in groups A and B compared to the control group (group A DVP, P = 0.001; group B DVP P = 0.002). GC-IPL, RNFL thickness, and RPC and SVP density in group A were significantly decreased compared to the control group or group B (all P < 0.05). In hypertensive patients, GC-IPL and RNFL thickness were negatively correlated with severity of HTNR (GC-IPL, r = –0.331, P < 0.001; RNFL, r = –0.583, P < 0.001) and level of home blood pressure monitoring (HBPM) (GC-IPL, r = –0.160, P = 0.050; RNFL, r = –0.282, P = 0.001) and were positively correlated with SVP (GC-IPL, r = 0.267, P = 0.002; RNFL, r = 0.361, P < 0.001) and RPC density (GC-IPL, r = 0.298, P < 0.001; RNFL, r = 0.663, P < 0.001). Among subjects with grade 2 or 3 retinopathy, the superior RNFL was significantly thinner in patients with high HBPM level than in those with normal HBPM level (grade 2, P = 0.016; grade 3, P = 0.006).

Conclusions

Reduction of retinal vessel density and RNFL thickness is observed in patients with HTNR and is inversely associated with level of HBPM.

Longitudinal changes in the peripapillary retinal nerve fiber layer thickness in the fellow eyes of unilateral retinal vein occlusion

To analyze longitudinal changes in peripapillary retinal nerve fiber layer (pRNFL) thicknesses over time in the fellow eyes of patients with unilateral retinal vein occlusion (RVO). A total of 47 patients with unilateral RVO and 47 healthy controls were enrolled. The mean and sectoral pRNFL thicknesses were measured using spectral domain-optical coherence tomography at 1 year intervals, and followed for 3 years. Linear mixed models were performed to calculate and compare the reduction rates of pRNFL thicknesses over time. The mean pRNFL thickness decreased significantly during the 3-year follow-up, with a significant decrease over time in both groups. The reduction rate in mean pRNFL thicknesses was -0.41 μm/year in the control group and -0.68 μm/year in the fellow eyes of RVO group, and the decrease was significantly higher in the fellow eyes of RVO group than in the control group (p < 0.001). Using a multivariate linear mixed model, age (estimate: -0.41, p = 0.011) and hypertension (HTN) (estimate: -6.51, p = 0.014) were significantly associated with the reduction in mean pRNFL thicknesses in fellow eyes of RVO group. The fellow eyes of RVO patients showed a greater reduction in pRNFL thickness over time than normal controls. Age and HTN should be considered as factors to decrease the pRNFL thickness over time in fellow eyes of RVO group.