Neutrophil/Lymphocyte Ratio as an Inflammatory Predictor of Dry Eye Disease: A Case-Control Study

New Biomarkers for Patients With Fungal Keratitis From Blood Routine Examination: Neutrophil-to-Lymphocyte Ratio and Platelet-to-Lymphocyte Ratio

Purpose: To assess the potential of neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) as novel diagnostic and prognostic biomarkers in fungal keratitis (FK). Methods: This study was carried out retrospectively in 77 FK patients and 77 matched cataract controls from Henan Eye Hospital. Peripheral venous blood samples were collected via venipuncture and analyzed using complete blood count for routine clinical evaluation. FK patients were classified into three subgroups: Fusarium, Aspergillus, and Candida groups. Inflammation severity was quantified using standardized clinical scoring. The treatment modalities were used to divide the FK patients into enucleation and nonenucleation groups. Results: NLR and PLR were significantly elevated in FK versus controls (p < 0.001). NLR correlated strongly with inflammation scores (r = 0.535, p < 0.0001), exceeding PLR's moderate correlation (r = 0.311, p=0.0059). FK patients in the enucleation group had significantly higher NLR (p=0.012) and PLR (p=0.021) values than those in the nonenucleation group. There were no significant biomarker differences across fungal species (p > 0.05). Conclusion: Elevated NLR and PLR values during routine laboratory testing might serve as supplementary indicators for early suspicion of FK and monitoring inflammatory progression, particularly in resource-limited settings where specialized ophthalmic diagnostics are unavailable.

Investigating Neutrophil-to-Lymphocyte and C-Reactive Protein-to-Albumin Ratios in Type 2 Diabetic Patients with Dry Eye Disease

BACKGROUND

Patients with Diabetes mellitus (DM) are at risk of developing dry eye disease (DED). We investigated routine laboratory parameters in patients with type 2 DM (T2D) and T2D-DED to identify potential inflammatory markers.

METHODS

A retrospective study of 241 randomly selected patients (30 DED non-diabetic, 120 T2D, and 91 with T2D-DED). The neutrophil-to-lymphocyte ratios (NLR), CRP-to-albumin ratios (CAR), and the glycosylated haemoglobin A1c (HbA1c) results were correlated between groups.

RESULTS

The NLR and HbA1c were significantly higher in the T2D-DED group (p≤0.001 and 0.0001, respectively) when compared with T2D and DED non-diabetic groups. CAR was insignificantly high in the three groups (p=0.192). A positive correlation was identified between CAR and NLR in T2D-DED patients (p= 0.008).

CONCLUSION

In T2D-DED patients, NLR was significantly high and positively correlate with CAR. These results predicate diabetes with dry eye complications, and biomarker-mediated inflammation may have important roles in DED pathogenesis.

Assessment of leukocyte and systemic inflammation index ratios in dyslipidemia patients with dry eye disease: a retrospective case‒control study

BACKGROUND

Dry eye disease (DED) is a complication of dyslipidemia (DLP) that is caused by metabolic syndrome and increased inflammation. This research aimed to assess leukocyte and systemic inflammation index ratios as potential biomarkers for systemic inflammation in dyslipidemia patients with dry eye disease (DLP-DED).

METHODS

Several blood biomarkers were studied in 32 patients with DLP-DED (study group) and 63 patients with DLP-only (control group). The evaluated blood biomarkers included specific systemic inflammation index ratios, such as the neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), monocyte-to-lymphocyte ratio (MLR), and neutrophil-to-lymphocyte and platelet ratio (NLPR), and lipid profiles, such as total cholesterol (TC), high-density lipoprotein cholesterol (HDL), low-density lipoprotein cholesterol (LDL), triglyceride (TG), albumin (ALB), and C-reactive protein (CRP) levels.

RESULTS

Lymphocyte levels were significantly greater in the DLP-DED group than in the DLP-only group (P = 0.044). In addition, a significant negative correlation between HDL and the NLPR (P = 0.007; r= -0.428) and a significant negative correlation between the serum ALB concentration and the PLR (P = 0.008; r= -0.420) were identified as potential inflammatory predictors of DLP-DED.

CONCLUSION

The findings of this study suggest that patients with DLP-DED may benefit from routine blood monitoring of their elevated lipid profile and blood inflammatory biomarkers, such as CRP, leukocytes, and systemic inflammation index ratios (NLR, PLR, MLR, and NLPR), to reduce the complications of DLP on ocular health. The correlation data suggest that the NLPR, PLR, serum ALB concentration, and serum HDL concentration may be valuable inflammatory biomarkers in DLP-DED patients. More research is required to ascertain the significance of the NLR, PLR, MLR, and NLPR and the additive role that leukocytes play.

Assessment of the systemic immune-inflammation index in type 2 diabetic patients with and without dry eye disease: A case-control study

Background

The inflammation plays a role in the pathophysiology of type-2 diabetes progression, and the mechanism remains unclear. The systemic immune-inflammation index (SII) is a novel inflammatory marker for type 2 diabetes patients and integrates multiple indicators in complete blood counts and routine blood tests.

Aim

Since there is no international diagnostic standard for dry eye disease (DED), this study uses low-cost inflammatory blood biomarkers to investigate the correlation between SII and DM2-DED and determine the diagnosis indices of other biomarkers in DM2-DED.

Methodology

A case-control retrospective analysis of totel patients n = 293 randomly selected and categorized into four groups: DED, DM2, DM2-DED, and healthy subjects. Demographic and blood biomarker variables were classified as categorical and continuous variables. The platelet-to-lymphocyte ratio (PLR), lymphocytes-to-lymphocyte ratio, neutrophil-to-lymphocyte ratio (NLR), and SII were calculated platelet count multiply by NLR and analyzed for their correlation for all groups.

Results

Focusing on DM2-DED patients was more common in females, 59.6%, than in males, 40.2%. The mean ages were 60.7 ± 11.85 years, a statistically significant difference with all groups. In the study group DM2-DED, there was an increase in all blood markers compared to all remaining groups except PLR. Only neutrophil, hemoglobin A1c (HbA1c), and fasting blood sugar levels were statistically significant differences in DM2-DED patients (p > 0.001, p < 0.001, and p < 0.001, respectively) compared to all groups. There was a positive correlation between HbA1c and PLR, HbA1c and NLR, and HbA1c and SII (r = 0.037, p = 0.705; r = 0.031, p = 0.754; and r = 0.066, p < 0.501, respectively) in the DM2-DED group.

Conclusion

This study demonstrated that elevated SII values were linked to elevated HbA1c in DM2-DED patients. The potential of SII and HbA1c as early diagnostic indicators for ocular problems associated with diabetes mellitus is highlighted by their favorable connection in diagnosing DM2-DED.

The inflammatory potential of diet is associated with the risk of age-related eye diseases

BACKGROUND & AIMS

Inflammation is involved in the pathogenesis of cataract, age-related macular degeneration (AMD), and possibly open-angle glaucoma (OAG). We assessed whether the inflammatory potential of diet (quantified using the dietary inflammatory index; DII) affects the incidence of these common blinding age-related eye diseases. Serum inflammation markers were investigated as possible mediators.

METHODS

Participants aged >45 years were selected from the prospective, population-based Rotterdam Study. From 1991 onwards, every 4-5 years, participants underwent extensive eye examinations. At baseline, blood samples and dietary data (using food frequency questionnaires) were collected. The DII was adapted based on the data available. Of the 7436 participants free of eye diseases at baseline, 4036 developed incident eye diseases during follow-up (cataract = 2895, early-intermediate AMD = 891, late AMD = 81, OAG = 169).

RESULTS

The adapted DII (aDII) ranged from -4.26 (i.e., anti-inflammatory) to 4.53 (i.e., pro-inflammatory). A higher aDII was significantly associated with increased inflammation. A higher neutrophil-lymphocyte ratio (NLR) was associated with an increased risk of cataract and AMD. Additionally, complement component 3c (C3c) and systemic immune-inflammation index (SII) were associated with increased risks of cataract and late AMD, respectively. Every point increase in the aDII was associated with a 9% increased risk of cataract (Odds ratio [95% confidence interval]: 1.09 [1.04-1.14]). The NLR and C3c partly mediated this association. We also identified associations of the aDII with risk of AMD (early-intermediate AMD, OR [95% CI]: 1.11 [1.03-1.19]; late AMD, OR [95% CI]: 1.24 [1.02-1.53]). The NLR partly mediated these associations. The aDII was not associated with OAG.

CONCLUSIONS

A pro-inflammatory diet was associated with increased risks of cataract and AMD. Particularly the NLR, a marker of subclinical inflammation, appears to be implicated. These findings are relevant for patients with AMD and substantiate the current recommendations to strive for a healthy lifestyle to prevent blindness.

Association between poor sleep quality and an increased risk of dry eye disease in patients with obstructive sleep apnea syndrome

Purpose

Obstructive sleep apnea (OSA) is related to an increased incidence of dry eye disease (DED). However, their exact relationship is unknown and requires further well-designed studies with advanced mechanisms detection.

Patients and methods

This case–control study included 125 OSA cases and 125 age–gender-matched controls enrolled in the hospital between 1 January and 1 October 2021. OSA diagnosis and classification were performed using a polysomnography (PSG) assay. Detailed ophthalmological examinations, including the Schirmer I test, corneal staining, and ocular surface disease index (OSDI), were used to detect DED-related parameters. A comprehensive ocular surface assay was performed to measure a series of parameters, including first non-invasive first tear film break-up time (f-NIBUT), average non-invasive first tear film break-up time (av-NIBUT), tear meniscus height (TMH), and loss of meibomian gland. In addition, the Pittsburgh Sleep Quality Index (PSQI) scale was used to assess sleep quality.

Results

Compared to the control, the OSA group showed an increased DED risk (P = 0.016) along with an increased PSQI score and a higher rate of poor quality sleep (P < 0.001 and P = 0.007, respectively). Stratification of OSA cases indicated that DED-related parameters were impaired in patients with severe OSA (P < 0.05). The analysis of DED-parameters-related factors showed significant correlations between OSA-related indexes and PSQI (P < 0.05). Moreover, the poor sleep quality group in the OSA cases showed worse DED-related parameters (P < 0.05), which was not observed in the control group.

Conclusion

OSA, especially the severe stage OSA, was related to an increased risk of DED. Also, sleep quality was correlated with the onset of both OSA and DED, where poor sleep quality revealed a relationship between OSA and the risk of DED. Overall, our findings provided evidence for advanced management of DED and OSA in future.

The Diagnostic Value of Neutrophil to Lymphocyte Ratio as an Effective Biomarker for Eye Disorders: A Meta-Analysis

The neutrophil to lymphocyte ratio (NLR) reflects a dynamic relationship between the innate (neutrophils) and adaptive (lymphocytes) cellular immune response. This systematic review and meta-analysis was conducted to critically evaluate the literature regarding the use of the NLR as a reliable means to detect several ocular disorders. Our study was registered with the PROSPERO (ID: CRD42022314850). Three databases, including PubMed, Embase, Scopus, and the Web of Science, were searched on September 9, 2022, with no restrictions on the article's language. Finally, 32 articles were recognized as eligible for our meta-analysis. We found that patients with eye diseases had significantly elevated levels of NLR in comparison to healthy controls (SMD =0.53, 95% CI =0.35-0.71, P < 0.001). In subgroup analysis, patients with keratoconus (SMD =0.69; 95% CI =0.33-1.05, P < 0.001), glaucoma (SMD =0.56, 95% CI =0.25-0.87, P < 0.001), pterygium (SMD =0.14; 95% CI =0.01-0.26, P < 0.001), and idiopathic epiretinal membrane (SMD =0.14; 95% CI =0.01-0.26, P < 0.001) had higher levels of NLR compared to healthy controls. However, NLR levels of patients with dry eye disease were similar to healthy controls (SMD =0.32, 95% CI = -0.49-1.13, P = 0.435). It can be said that NLR is a valuable marker of systemic inflammation, which is significantly increased in many eye disorders, suggesting that inflammation plays a key role in the pathophysiology of these diseases.

Systemic immune-inflammation index could be associated with pseudophakic cystoid macular edema after an uneventful phacoemulsification surgery in patients without risk factors

BACKGROUND

To evaluate the association between serum biomarkers and pseudophakic cystoid macular edema (PCME) in eyes without risk factors after uneventful phacoemulsification cataract surgery.

METHODS

This is a case-control study. Patients without risk factors and who developed clinically significant PCME after uncomplicated phacoemulsification surgery were enrolled in the study. The age- and sex-matched control group that had normal fundus examination findings and 10/10 visual acuity in the first week, first month and following postoperative control visits was randomly recruited from the same study cohort. The neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and systemic immune-inflammation index (SII) were obtained from the preoperative complete blood count (CBC) test and compared between the two groups. Linear regression analysis was used to assess the relationship between central macular thickness (CMT) and biomarkers. A binary logistic regression model was generated to evaluate the significance of the biomarkers in predicting PCME. The receiver operating characteristic (ROC) curves of the significant parameters in the logistic regression model were presented to detect the area under the curve (AUC), the cut-off point, the sensitivity and the specificity.

RESULTS

The study cohort included 5352 patients. Of these patients, 52 (0.97%) met the inclusion criteria, and 60 age- and sex-matched patients were recruited as the control group. PLR, NLR, and SII were significantly different between the two groups (p = 0.006, p = 0.002, p < 0.001, respectively). According to the linear regression analysis, SII was found to have a significant relationship with CMT (p < 0.001). Only SII was assessed as significant in the logistic regression model (p = 0.046). In the ROC curve, the AUC of SII was 0.709. The sensitivity and specificity of SII for PCME prediction were 65.38% and 75%, respectively, and the cut-off point was 433.70.

CONCLUSION

SII is associated with the occurrence of PCME in eyes without risk factors after uneventful phacoemulsification surgery. SII could be a useful tool to predict PCME in eyes without risk factors.

Association of Dry Eye Diseases and Auditory Sensitivity

This study aimed to evaluate the association between dry eye and inner ear diseases in a Korean population. Methods: Data from the Korean National Health and Nutrition Survey (KNHANES V, 2010−2012), a national cross-sectional health examination and survey, were collected by the Korea Centers for Disease Control and Prevention. The association between dry eye and inner ear disease was determined using the chi-square test and logistic regression analysis. The individuals were divided into two age groups (<60 and ≥60 years). Results: In total, 17,542 individuals (n = 11,932 in the <60 years group and n = 5610 in the ≥60 years group) were enrolled. After adjusting for confounding factors, the logistic regression model revealed that the associated factors were dizziness and loss of balance experience (OR, 1.315; 95% CI, 1.143−1.513), self-awareness of abnormal voice (OR, 1.372; 95% CI, 1.120−1.679), subjective hearing discomfort (OR, 1.278; CI, 1.084−1.506), and tinnitus (OR, 1.265; 95% CI, 1.101−1.453). The inversely associated factor for dry eye was bilateral hearing loss (OR, 0.497; 95% CI, 0.367−0.672). The hearing threshold was lower in the dry eye group than in the non-dry eye group (p < 0.05). Conclusions: Tinnitus was associated with dry eye and bilateral hearing loss was inversely associated with dry eye. These results suggest that hypersensitivity of the senses and nerves, which is neuropathic hyperesthesia, is one of the main mechanisms of dry eye. Treatment of neuropathy may help in treating dry eye associated with dizziness or tinnitus.

The Role of Neutrophil Extracellular Traps in the Ocular System

Purpose: Neutrophils remain at the top of congenital and adaptive immune systems. The past 20 years witnessed a steep rise in the interest in neutrophil extracellular traps (NETs), which are a novel type of anti-pathogen mechanism coordinated with neutrophils. However, accumulating data revealed that excessive NETs in the host were associated with exacerbated inflammation, thrombosis, and autoimmunity. Increasing evidence found the participation of NETs in the pathophysiological process of many infectious and sterile diseases in the ocular system. Therefore, we discussed the role of neutrophil extracellular traps in the ocular system in this review.Methods: Articles were searched on PubMed, Embase and Web of science up to December 2021.Results: In this review, we exhibited the protective role of neutrophils patrolling the ocular surface from invading pathogens and their contribution to exacerbated inflammation and thrombogenesis in some ocular diseases. We also discussed the physiological and pathological processes of NET generation to identify novel biomarkers and therapeutic targets to interrupt immoderate NET formation and alleviate NET-induced harmful effects.Conclusions: Neutrophils and NETs are quite important for immune responses in the ocular system, while their negative effects on ocular tissue should also be emphasized, which could serve as novel biomarkers and potential therapeutic targets.

A new non-human primate model of desiccating stress-induced dry eye disease

Dry eye disease (DED), a multifactorial ocular surface disease, is estimated to affect up to 34% of individuals over 50 years old. Although numerous animal models, including rodents and rabbits, have been developed to mimic the pathophysiologic mechanisms involved in dry eye, there is a lack of non-human primate (NHP) models, critical for translational drug studies. Here, we developed a novel desiccating stress-induced dry eye disease model using Rhesus macaque monkeys. The monkeys were housed in a controlled environment room for 21 to 36 days under humidity, temperature, and airflow regulation. Following desiccating stress, NHPs demonstrated clinical symptoms similar to those of humans, as shown by increased corneal fluorescein staining (CFS) and decreased tear-film breakup time (TFBUT). Moreover, corticosteroid treatment significantly reduced CFS scoring, restored TFBUT, and prevented upregulation of tear proinflammatory cytokines as observed in dry eye patients following steroid treatment. The close resemblance of clinical symptoms and treatment responses to those of human DED patients provides great translational value to the NHP model, which could serve as a clinically relevant animal model to study the efficacy of new potential treatments for DED.

The omega-3 index is inversely associated with the neutrophil-lymphocyte ratio in adults'

The neutrophil-lymphocyte ratio (NLR) is a biomarker of systemic inflammation and measures innate-adaptive immune system balance. The omega-3-index (O3I) measures the amount of EPA+DHA in blood. Both a low O3I and an elevated NLR are associated with increased risk for chronic disease and mortality, including cardiovascular diseases and cancer. Hypothesizing that low O3I may partly contribute to systemic chronic inflammation, we asked if a relationship existed between O3I and NLR in healthy adults (≥18 y, n = 28,871, 51% female) without inflammation [C-reactive protein (CRP) <3 mg/mL)] who underwent a routine clinical assessment. NLR was inversely associated with O3I before (p < 0.0001) and after adjusting for age, sex, BMI, and CRP (p < 0.0001). Pearson correlations of other variables with NLR were r = 0.06 (CRP), r = 0.14 (age), and r = 0.01(BMI). In this healthy population, an O3I < 6.6% was associated with increasing NLR whereas NLR remained relatively constant (low) when O3I > 6.6%, suggestive of a quiescent, balanced immune system.