Longitudinal changes in the thickness of the ganglion cell-inner plexiform layer in patients with hypertension: a 4-year prospective observational study

Longitudinal changes in each retinal layer thickness in patients with non-ischemic central retinal vein occlusion

BACKGROUND

To identify longitudinal changes in each retinal layer thickness in central retinal vein occlusion (CRVO) patients with resolved macular edema (ME).

METHODS

In this retrospective observational study, CRVO patients without a recurrence of ME for more than 3 years and normal controls were enrolled. Each retinal layer thickness of the parafoveal area, including ganglion cell complex (GCC), inner nuclear layer (INL), outer plexiform layer (OPL), outer nuclear layer (ONL), photoreceptor layer (PRL), and retinal pigment epithelium (RPE) was measured. After the resolution of ME, three more examinations with a 1-year interval were analyzed.

RESULTS

A total of 98 eyes were enrolled, 50 eyes for the control group and 48 eyes for the CRVO group. The baseline GCC thickness was 114.2 ± 15.6 μm and 104.2 ± 25.4 μm in the control and CRVO groups, respectively, which was significantly different (P = 0.022). The thicknesses of other layers including INL, OPL, ONL, PRL, and RPE were not significantly different at baseline. The reduction rate of GCC, INL, OPL, and ONL was - 3.92, - 1.33, - 0.91, and - 2.31 μm/year in the CRVO group, whereas no significant reductions were observed in the control group. Best-corrected visual acuity was significantly associated with changes in the GCC, OPL, and ONL in the CRVO group.

CONCLUSIONS

In patients with CRVO, even in the absence of recurrent ME, retinal damage progresses over time, evidenced by thinning of the inner retina and outer retina including OPL and ONL. These changes may be associated with alterations in visual function.

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.

Arterial hypertension and retinal layer thickness: the Beijing Eye Study

PURPOSE

To investigate relationships between blood pressure and the thickness of single retinal layers in the macula.

METHODS

Participants of the population-based Beijing Eye Study, free of retinal or optic nerve disease, underwent medical and ophthalmological examinations including optical coherence tomographic examination of the macula. Applying a multiple-surface segmentation solution, we automatically segmented the retina into its various layers.

RESULTS

The study included 2237 participants (mean age 61.8±8.4 years, range 50-93 years). Mean thicknesses of the retinal nerve fibre layer (RNFL), ganglion cell layer (GCL), inner plexiform layer, inner nuclear layer (INL), outer plexiform layer, outer nuclear layer/external limiting membrane, ellipsoid zone, photoreceptor outer segments (POS) and retinal pigment epithelium-Bruch membrane were 31.1±2.3 µm, 39.7±3.5 µm, 38.4±3.3 µm, 34.8±2.0 µm, 28.1±3.0 µm, 79.2±7.3 µm, 22.9±0.6 µm, 19.2±3.3 µm and 20.7±1.4 µm, respectively. In multivariable analysis, higher systolic blood pressure (SBP) and diastolic blood pressure (DBP) were associated with thinner GCL and thicker INL, after adjusting for age, sex and axial length (all p<0.0056). Higher SBP was additionally associated with thinner POS and higher DBP with thinner RNFL. For an elevation of SBP/DBP by 10 mm Hg, the RNFL, GCL, INL and POS changed by 2.0, 3.0, 1.5 and 2.0 µm, respectively.

CONCLUSIONS

Thickness of RNFL, GCL and POS was inversely and INL thickness was positively associated with higher blood pressure, while the thickness of the other retinal layers was not significantly correlated with blood pressure. The findings may be helpful for refinement of the morphometric detection of retinal diseases.

Retinal thickness as a biomarker of cognitive impairment in manifest Huntington's disease

BACKGROUND

Cognitive decline has been reported in premanifest and manifest Huntington's disease but reliable biomarkers are lacking. Inner retinal layer thickness seems to be a good biomarker of cognition in other neurodegenerative diseases.

OBJECTIVE

To explore the relationship between optical coherence tomography-derived metrics and global cognition in Huntington's Disease.

METHODS

Thirty-six patients with Huntington's disease (16 premanifest and 20 manifest) and 36 controls matched by age, sex, smoking status, and hypertension status underwent macular volumetric and peripapillary optical coherence tomography scans. Disease duration, motor status, global cognition and CAG repeats were recorded in patients. Group differences in imaging parameters and their association with clinical outcomes were analyzed using linear mixed-effect models.

RESULTS

Premanifest and manifest Huntington's disease patients presented thinner retinal external limiting membrane-Bruch's membrane complex, and manifest patients had thinner temporal peripapillary retinal nerve fiber layer compared to controls. In manifest Huntington's disease, macular thickness was significantly associated with MoCA scores, inner nuclear layer showing the largest regression coefficients. This relationship was consistent after adjusting for age, sex, and education and p-value correction with False Discovery Rate. None of the retinal variables were related to Unified Huntington's Disease Rating Scale score, disease duration, or disease burden. Premanifest patients did not show a significant association between OCT-derived parameters and clinical outcomes in corrected models.

CONCLUSIONS

In line with other neurodegenerative diseases, OCT is a potential biomarker of cognitive status in manifest HD. Future prospective studies are needed to evaluate OCT as a potential surrogate marker of cognitive decline in HD.

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.

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.

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.

Retinal Thickness Predicts the Risk of Cognitive Decline in Parkinson Disease

Objective

This study was undertaken to analyze longitudinal changes of retinal thickness and their predictive value as biomarkers of disease progression in idiopathic Parkinson's disease (iPD).

Methods

Patients with Lewy body diseases were enrolled and prospectively evaluated at 3 years, including patients with iPD (n = 42), dementia with Lewy bodies (n = 4), E46K‐SNCA mutation carriers (n = 4), and controls (n = 17). All participants underwent Spectralis retinal optical coherence tomography and Montreal Cognitive Assessment, and Unified Parkinson's Disease Rating Scale score was obtained in patients. Macular ganglion cell–inner plexiform layer complex (GCIPL) and peripapillary retinal nerve fiber layer (pRNFL) thickness reduction rates were estimated with linear mixed models. Risk ratios were calculated to evaluate the association between baseline GCIPL and pRNFL thicknesses and the risk of subsequent cognitive and motor worsening, using clinically meaningful cutoffs.

Results

GCIPL thickness in the parafoveal region (1‐ to 3‐mm ring) presented the largest reduction rate. The annualized atrophy rate was 0.63μm in iPD patients and 0.23μm in controls (p < 0.0001). iPD patients with lower parafoveal GCIPL and pRNFL thickness at baseline presented an increased risk of cognitive decline at 3 years (relative risk [RR] = 3.49, 95% confidence interval [CI] = 1.10–11.1, p = 0.03 and RR = 3.28, 95% CI = 1.03–10.45, p = 0.045, respectively). We did not identify significant associations between retinal thickness and motor deterioration.

Interpretation

Our results provide evidence of the potential use of optical coherence tomography–measured parafoveal GCIPL thickness to monitor neurodegeneration and to predict the risk of cognitive worsening over time in iPD. ANN NEUROL 2021;89:165–176

Characteristics of the inner retinal layer in the fellow eyes of patients with unilateral exudative age-related macular degeneration

OBJECTIVE

To investigate the thicknesses of the ganglion cell-inner plexiform layer (GC-IPL) and retinal nerve fiber layer (RNFL) of the fellow eyes of patients with unilateral exudative age-related macular degeneration (AMD).

METHODS

A total of 107 patients with unilateral exudative AMD [34 of typical choroidal neovascularization (tCNV), Group A; 73 of polypoidal choroidal vasculopathy (PCV), Group B] and 73 normal control eyes (Group C) were included. Drusen and subretinal drusenoid deposits were assessed in all participants using fundus photography, autofluorescence, and optical coherence tomography (OCT). The GC-IPL and RNFL thicknesses were measured using Cirrus HD-OCT and compared among groups. Linear regression analyses were used to evaluate the factors associated with GC-IPL thicknesses.

RESULTS

The average GC-IPL thicknesses of Groups A, B, and C were 77.09 ± 3.87, 80.10 ± 6.61, and 80.88 ± 6.50 μm, respectively (p = 0.022). Sectoral GC-IPLs and central macular thicknesses (CMTs) were significantly different among groups (all, p <0.05), whereas none of the RNFL parameters differed significantly (all, p >0.05). Multivariate linear regression analyses revealed that age (p <0.001), CMT (p <0.001), and tCNV (p = 0.013) were significantly associated with average GC-IPL thickness, and the rate of reduction of GC-IPL thickness with increasing age in the fellow eyes of tCNV patients was higher than those in the PCV and control groups.

CONCLUSIONS

Unilateral tCNV patients exhibited statistically significant reduction of the GC-IPL thickness in the fellow eyes, compared to values of the fellow eyes of unilateral PCV patients or control patients. RNFL values trended to be lower but did not reach statistical significance.