Mean Platelet Volume in Patients with Nonarteritic Anterior Ischemic Optic Neuropathy

Exploring the contribution of carotid artery disease to the onset of non-arteritic ischemic optic neuropathies: A systematic review

PURPOSE

The role of carotid artery disease (CAD) in the development of various types of ocular arterial occlusive disorders has often been reported. This systematic review aims to evaluate and review the current evidence regarding the role of CAD and the subsequent carotid artery hemodynamic alterations in the development of non-arteritic anterior (NA-AION) and posterior (NA-PION) ischemic optic neuropathy.

METHODS

We systematically reviewed studies following Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. We systematically searched PubMed, Embase, and Scopus databases for relevant studies that clearly assessed the role of CAD and the subsequent carotid artery hemodynamic alterations in the development of NA-AION and NA-PION. All studies that examined the associations between CAD and the development of NA-AION and NA-PION in adults aged 18 years or older were synthesized. Quality assessment using the Newcastle-Ottawa Scale (NOS), and Joanna Briggs Institute (JBI) Critical Appraisal Checklist for Case Reports and Case-Series were also conducted.

RESULTS

Our search identified 1933 manuscripts published in the English language. The number of participants with non-arteritic ischemic optic neuropathy (NA-ION) ranged from 1 to 191, with a total of 478 patients experiencing either NA-AION (410 out of 478), NA-PION (13 out of 478), or a combination of thereof (1 out of 478). The number of participants with NA-ION due to atherosclerosis ranged from 1 to 191, with a total of 376 patients.

CONCLUSIONS

Although carotid artery disease may rarely contribute to the development of NA-ION, it should be considered as a possible cause of NA-ION.

Understanding the Etiopathogenesis of Non-Arteritic Anterior Ischemic Optic Neuropathy with Laboratory Findings

Objectives

The role of inflammation and hemostasis in non-arteritic anterior ischemic optic neuropathy (NAION) was investigated by examining related blood tests. The predictive values of these laboratory indicators and their effects on prognosis were reviewed.

Methods

In this study, 48 patients diagnosed with NAION and 50 healthy volunteers were included. All subjects underwent full ophthalmological examination. All patients were treated with oral corticosteroids (methylprednisolone 1 mg/kg/day) for 15 days after that corticosteroid medication was reduced and stopped. Each patient was monitored at least for 12 months. The mean platelet volume (MPV), platelet distribution width (PDW), neutrophil/lymphocyte ratio (NLR), and red cell distribution width (RDW) values were recorded. These findings were compared with control group.

Results

The mean MPV, RDW, and NLR values were significantly higher in NAION group (respectively, p<0.001, p=0.006, and p<0.001). There was no statistically significant difference between group 1 and group 2 in PDW values, but the mean PDW value was higher in the patient group compared to the control group (p=0.435). Based on the receiver operating characteristic (ROC) curve, the NLR had the strongest predictive value. This was followed by MPV, RDW, and PDW with lower diagnostic predictive values.

Conclusion

MPV, NLR, and RDW were found to be elevated and have diagnostic predictive values in NAION patients. Easily accessible and simple laboratory methods could help us show systemic inflammation and ischemic events in NAION patients. As a result, inflammatory reactions besides ischemic changes may play a role in the etiopathogenesis of NAION. These biomarkers can be evaluated to ensure that patients with risk factors for the development of NAION.

Risk Factors for Non-arteritic Anterior Ischemic Optic Neuropathy: A Large Scale Meta-Analysis

Objective: We conducted a meta-analysis to explore all the potential risk factors for non-arteritic anterior ischemic optic neuropathy (NAION) based on the published literature. Methods: A comprehensive literature search through the online databases was performed to obtain studies concerning the risk factors of NAION up to June 2020. Pooled unadjusted odds ratios (ORs) or rate ratios (RRs) were calculated to evaluate the weight of risk factors. This study was registered in PROSPERO under the number CRD42018084960. Results: Our meta-analysis included 49 original studies comprising of more than 10 million patients. The following risk factors were proved to be significantly associated with NAION: male gender (OR = 1.67, 95% CI: 1.50-1.85, P < 0.00001), hypertension (RR = 1.28, 95% CI: 1.20-1.37, P < 0.00001), hyperlipidemia (RR = 1.43, 95% CI: 1.26-1.62, P < 0.00001), diabetes mellitus (DM) (RR = 1.53, 95% CI: 1.36-1.73, P < 0.00001), coronary heart disease (CHD) (RR = 1.68, 95% CI: 1.24-2.27, P = 0.0008), sleep apnea (RR = 3.28, 95% CI: 2.08-5.17, P < 0.00001), factor V Leiden heterozygous (RR = 2.21, 95% CI: 1.19-4.09, P = 0.01), and medication history of cardiovascular drugs. Conclusion: We concluded that the above risk factors were significantly related to NAION. Better understanding of these risk factors in NAION can help the direct therapeutic approaches.

Red Cell Distribution Width (RDW) and Complete Blood Cell Count-Derived Measures in Non-Arteritic Anterior Ischemic Optic Neuropathy

Purpose: To assess the role of complete blood cell count (CBC) dimensional indices and CBC-derived measures in non-arteritic anterior ischemic optic neuropathy (NA-AION). Methods: In this retrospective case-control survey, 37 newly diagnosed NA-AION patients and 37 sex- and age-matched cataract controls were enrolled in 2017-2018. On the same day of NA-AION diagnosis, a blood sample was collected and CBC was determined using an automatic blood counter. CBC dimensional indices, such as mean platelet volume (MPV) and red cell distribution width (RDW), and CBC-combined indices, including neutrophil/lymphocyte ratio (NLR), derived NLR [dNLR = neutrophils/(white blood cells - neutrophils)], and platelet/lymphocyte ratio (PLR), were evaluated. Erythrocyte sedimentation rate (ESR) was also measured. Results: Mean platelet count, median MPV, RDW, NLR, and dNLR were 221±48 x 10⁹/L, 8.2 fL (IQR=7.6-8.9), 13% (IQR=12-14.5), 2.50 (IQR=1.77-3.06), and 1.73 (IQR=1.31-2.07) in NA-AION patients and 248±56 x 10⁹/L, 7.60 fL (IQR=7.05-8.25), 12% (IQR=11.6-13), 1.95 (IQR=1.43-2.49) and 1.36 (IQR=1.07-1.69) in controls. NA-AION patients showed significantly lower platelet count (p=0.03) and significantly higher median values of MPV (p=0.01), RDW (p=0.015), NLR (p=0.03), and dNLR (p=0.01). Multivariate logistic regression models disclosed a significant correlation only between higher levels of RDW and NA-AION (p≤0.05). The attributable risk of the association between NA-AION and RDW was 33%. Conclusions: Results suggest that RDW may be somehow involved in the pathogenesis of NA-AION. However, high-quality cohort studies are warranted to confirm whether, or not, an altered RDW may be considered a potential biomarker of this vascular disorder affecting the optic nerve.

Mean Platelet Volume, Red Cell Distribution Width, and Complete Blood Cell Count Indices in Retinal Vein Occlusions

PURPOSE

To evaluate the role of some complete blood cell count (CBC)-derived measures in retinal vein occlusion (RVO).

METHODS

This was a retrospective case-control study, including 127 newly diagnosed RVO patients and 127 sex- and age-matched subjects without RVO. A blood sample was obtained and a complete blood cell count was performed. Neutrophil/lymphocyte ratio (NLR), derived NLR [dNLR = neutrophils/(white blood cells‒neutrophils)], and platelet/lymphocyte ratio (PLR) were calculated. We also performed a meta-analysis of the available data, ours included, on the correlation between mean platelet volume (MPV) and RVO. Standardized mean differences (SMD) were used to build forest plots and assess differences in MPV values between RVO patients and controls.

RESULTS

Median MPV and red cell distribution width (RDW) were 8.7 fL (IQR = 7.8-9.5) and 13.2% (IQR = 12.4-14.2) in RVO patients and 7.8 fL (IQR = 7.1-8.5) and 13% (IQR = 12-14) in controls. RVO patients had significantly higher values of MPV (P < .0001) and RDW (P = .005). There were no significant differences between the values of white blood cells, lymphocytes, neutrophils, platelets, NLR, dNLR, and PLR. Multivariable logistic regression analysis revealed a statistically significant correlation between increased MPV and RVO (OR = 1.74, 95% CI = 1.38-2.2, P < .0001). 519 RVO patients and 414 controls from 6 case-control studies were included in the meta-analysis. Pooled results disclosed that MPV values were significantly higher in RVO patients (SMD = 0.41 fL, 95% CI = 0.04-0.79, P = .032), but extreme heterogeneity was observed (I² = 86.1%, P < .001).

CONCLUSION

Results suggest lack of association between CBC-derived inflammatory indices and RVO. Conversely, MPV and, to a lesser extent, RDW may be disease biomarkers in RVO.

Research on Association of the Diameter of the Internal Carotid Artery Siphon and Nonarteritic Anterior Ischaemic Optic Neuropathy

Objective

To investigate the association of the diameter of the internal carotid artery siphon (ICAS) and nonarteritic anterior ischaemic optic neuropathy (NAION).

Methods

Thirty patients clinically diagnosed with NAION (unilateral affected) who presented to Beijing Friendship Hospital from January 2017 to October 2018 were selected. The eyes suffered from NAION were enrolled as the observation group, and the fellow healthy eyes were enrolled as the control group. The following indexes were measured: diameter of the ICAS and the ophthalmic artery (OA), intima-media thickness (IMT) of the internal carotid artery (ICA), degree of stenosis of the ICA and plaque formation, and hemodynamic parameters of the ICA and the short posterior ciliary arteries (SPCAs). All the values were compared between the two groups.

Results

The diameter of the ICAS in the observation group (0.30 ± 0.07 cm) significantly narrowed compared with that of the control group (0.32 ± 0.06 cm) (P < 0.05), but the diameter of the OA of the two groups had no significant difference. The detection rate of carotid atherosclerosis plaque, the average blood flow velocity (Vm), and the resistance index (RI) of the ICA in the observation group (46.67%, 26.81 ± 1.78 cm/s, and 0.72 ± 0.06) had significant differences compared with those of the control group (16.67%, 28.19 ± 2.75 cm/s, and 0.70 ± 0.05) (P < 0.05), but the gradings of ICA stenosis and IMT between the two groups had no significant differences. The peak systolic velocity (PSV) and the end diastolic velocity (EDV) of the SPCAs in the observation group (10.72 ± 2.88 cm/s and 3.43 ± 1.01 cm/s) were significantly lower than those of the control group (13.62 ± 3.93 cm/s and 4.59 ± 1.71 cm/s) (P < 0.05), but the RI of the SPCAs of the two groups had no significant differences.

Conclusion

The diameter of the ICAS has a close relationship with NAION.

Could Platelet Indices and Neutrophil to Lymphocyte Ratio Be New Biomarkers for Differentiation of Arteritic Anterior Ischemic Neuropathy from Non-Arteritic Type?

The aim of this study was to assess the possible relationship between AAION (arteritic anterior ischemic optic neuropathy) and NAION (non-arteritic anterior ischemic optic neuropathy) with blood platelet parameters and NLR (neutrophil-to-lymphocyte ratio). The medical records of 12 patients with AAION, 33 patients with NAION, and 35 healthy subjects were examined. MPV, PDW, and PCT values showed marked elevation in AAION and NAION groups compared with control group. The mean NLR was statistically significantly higher only in AAION group compared to the NAION and control groups, suggesting that platelet function plays an important role in AIONs and NLR might be used to differentiate AAION from NAION.

Association between coagulation function and patients with primary angle closure glaucoma: a 5-year retrospective case-control study

OBJECTIVE

To evaluate the association between coagulation function and patients with primary angle closure glaucoma (PACG).

DESIGN

A retrospective, hospital-based, case-control study.

SETTING

Shanghai, China.

PARTICIPANTS

A total of 1778 subjects were recruited from the Eye & ENT Hospital of Fudan University from January 2010 to December 2015, including patients with PACG (male=296; female=569) and control subjects (male=290; female=623).

OUTCOME MEASURES

Sociodemographic data and clinical data were collected. The one-way analysis of variance test was used to compare the levels of laboratory parameters among the mild, moderate and severe PACG groups. Multivariate logistic regression analyses were performed to identify the independent risk factors for PACG. The nomogram was constructed based on the logistic regression model using the R project for statistical computing (R V.3.3.2).

RESULTS

The activated partial thromboplastin time (APTT) of the PACG group was approximately 4% shorter (p<0.001) than that of the control group. The prothrombin time (PT) was approximately 2.40% shorter (p<0.001) in patients with PACG compared with the control group. The thrombin time was also approximately 2.14% shorter (p<0.001) in patients with PACG compared with the control group. The level of D-dimer was significantly higher (p=0.042) in patients with PACG. Moreover, the mean platelet volume (MPV) of the PACG group was significantly higher (p=0.013) than that of the control group. A similar trend was observed when coagulation parameters were compared between the PACG and control groups with respect to gender and/or age. Multiple logistic regression analyses revealed that APTT (OR=1.032, 95% CI 1.000 to 1.026), PT (OR=1.249, 95% CI 1.071 to 1.457) and MPV (OR=1.185, 95% CI 1.081 to 1.299) were independently associated with PACG.

CONCLUSION

Patients with PACG had a shorter coagulation time. Our results suggest that coagulation function is significantly associated with patients with PACG and may play an important role in the onset and development of PACG.

Carotid artery intimal medial thickness and carotid artery plaques in hypertensive patients with non-arteritic anterior ischaemic optic neuropathy

PURPOSE

To assess the correlation of carotid artery intimal medial thickness (C-IMT) and carotid artery plaque score (CPS) of the common carotid artery with non-arteritic anterior ischemic optic neuropathy (NAION) in hypertensive patients.

METHODS

This case-control study recruited 192 subjects. Forty-eight patients had NAION with systemic hypertension, 46 had hypertension without visual complaints, and 98 were normal controls. C-IMT and common carotid arterial plaque were measured by high-resolution vascular ultrasonography.

RESULTS

High-density lipoprotein (HDL) in patients with NAION (1.24 ± 0.31) was significantly lower than that of the Hypertensive group (1.39 ± 0.30, P = 0.034). The C-IMT in the affected side of patients with NAION (1.00 ± 0.23) was significantly increased compared to the unaffected side (0.83 ± 0.19, P < 0.001), the Hypertensive group (0.83 ± 0.17, P < 0.001), and the Normal group (0.69 ± 0.16, P < 0.001). The presence of carotid artery plaque was more frequent in the patients with NAION, compared to either the Hypertensive group (P = 0.001) or the Normal group (P < 0.001). By multiple regression analysis, lower high-density lipoprotein (HDL) (P = 0.009), thicker C-IMT (P = 0.002), CPS Grade = 1 (P = 0.028), and Grade = 2 (P = 0.005) were associated with increased NAION risk, when the NAION group compared with the Hypertensive group (OR > 1.0). Systolic blood pressure (P = 0.001), thicker C-IMT (P < 0.001), CPS Grade = 1 (P = 0.006), Grade = 2 (P = 0.002), and Grade = 3 (P = 0.015) were associated with increased NAION risk, when the NAION group compared with the Normal group (OR > 1.0).

CONCLUSIONS

C-IMT and CPS were associated with NAION in hypertensive patients, suggesting that NAION might be associated with carotid artery atherosclerosis. This association may be due to similar pathological changes of the inner vascular walls in the carotid artery and the arteries supplying the optic nerve head.

Role of Platelet Parameters on Neovascular Glaucoma: A Retrospective Case-Control Study in China

Purpose

Retinal vein occlusion (RVO) and diabetic retinopathy (DR) are two major sight-threatening diseases which may lead to neovascular glaucoma (NVG). The aim of this study was to explore the association between platelet parameters and NVG.

Methods

A total of 185 subjects were enrolled for the study from January, 2012 to December, 2015 at the Eye-ENT Hospital of Fudan University. Patients include those with NVG secondary to RVO (RVO group, n = 38), patients with NVG secondary to DR (DR group, n = 47), diabetics mellitus without retinopathy (DM group, n = 52), and healthy individuals (control group, n = 48). A complete ophthalmological examination including visual field examination, A-scan ultrasound, Fundus photography, and measurement of platelet parameters were performed for NVG subjects.

Results

There was no statistical difference in the mean age and gender among the RVO, DR, and control groups (p>0.05). The mean level of platelet distribution width (PDW) was higher (p<0.001) in the RVO group (15.16±2.13fl) and DR group (16.17±1.66fl) when compared with the control group (13.77±2.99fl). The mean plateletcrit (PCT) value of the RVO group (0.229±0.063%) was also higher (p = 0.049) than the control group (0.199±0.045). In the DR group, mean platelet volume (MPV) value (10.72±1.57fl) was significantly higher (p = 0.002) than the control group (9.75±0.89fl). A similar trend was observed when platelet parameters were compared among the 3 groups with respect to age. The mean level of PDW was significantly higher (p<0.001) in the DR group (16.17±1.66fl) compared with the DM group (13.80±3.32fl). Stepwise multiple logistic regression analysis revealed that PDW (OR = 1.44, 95%CI = 1.149–1.805, p = 0.002) and MPV (OR = 1.503, 95%CI = 1.031–2.192, p = 0.034) were associated with the DR group, PDW (OR = 1.207, 95%CI = 1.010–1.443, p = 0.039) and PCT (OR = 1.663, 95%CI = 1.870–2.654, p = 0.036) were associated with the RVO group.

Conclusion

Our results suggest that increased PDW and MPV are associated with the NVG secondary to DR group, elevated PDW and PCT are associated with the RVO group. It indicates that platelets might be an important factor in the onset and/or development of NVG.

Relationship between mean platelet volume and central serous chorioretinopathy

The aim of this study was to investigate the mean platelet volume (MPV) of patients with central serous chorioretinopathy (CSCR). Thirty patients were included in the study. Thirty healthy volunteers were recruited as the control group. All patients and control subjects underwent complete ocular examination. Hemoglobin, hematocrit, white blood cell, neutrophil, lymphocyte, platelet count, and MPV of the participants were recorded. Data of patients with CSCR were compared with the control subjects. Patients with CSCR had significantly higher MPV values (9.76 ± 1.36 fL) compared with the control subjects (8.37 ± 0.72 fL) (p = 0.004). No significant difference was found in platelet counts between the CSCR group and the control group (259 ± 53.75 and 243 ± 52.11 K/Ul, p = 0.253). According to the receiver operator characteristics curve analysis, the optimal cut-off value of MPV to predict the CSCR was >9.4, with 60.0 % sensitivity and 93.3 % specificity. Our results demonstrated that the MPV values were significantly higher in patients with CSCR. MPV may be used as a predictive tool for identifying risk for CSCR.