PERIODONTAL DISEASE AND AGE-RELATED MACULAR DEGENERATION: Results From the National Health and Nutrition Examination Survey III

Assessment of Relation between Periodontal Disease and Macular Degeneration

Background and Aim

Periodontal disease may result in chronic inflammation and bacteremia in some people. The study aimed to evaluate the connection between periodontal disease and macular degeneration.

Materials and Methods

The specialist dental surgeon conducted the dental examination using a community periodontal index probe. An ophthalmologist performed the eye examination. Age-related macular degeneration (AMD) was identified through specific criteria such as the existence of particular types of drusen and pigmentary abnormalities.

Results

Two hundred participants were part of the study. According to the data, factors such as advanced age, limited education, low income, hypertension, cardiovascular disease (CVD), and hepatitis B surface antigen (HBsAg) presence were strongly linked to AMD in all participants.

Conclusion

Multiple studies have indicated a connection between periodontitis in the mouth and macular degeneration in individuals under 60 years of age.

Periodontitis and Outer Retinal Thickness: a Cross-Sectional Analysis of the United Kingdom Biobank Cohort

Purpose

Periodontitis, a ubiquitous severe gum disease affecting the teeth and surrounding alveolar bone, can heighten systemic inflammation. We investigated the association between very severe periodontitis and early biomarkers of age-related macular degeneration (AMD), in individuals with no eye disease.

Design

Cross-sectional analysis of the prospective community-based cohort United Kingdom (UK) Biobank.

Participants

Sixty-seven thousand three hundred eleven UK residents aged 40 to 70 years recruited between 2006 and 2010 underwent retinal imaging.

Methods

Macular-centered OCT images acquired at the baseline visit were segmented for retinal sublayer thicknesses. Very severe periodontitis was ascertained through a touchscreen questionnaire. Linear mixed effects regression modeled the association between very severe periodontitis and retinal sublayer thicknesses, adjusting for age, sex, ethnicity, socioeconomic status, alcohol consumption, smoking status, diabetes mellitus, hypertension, refractive error, and previous cataract surgery.

Main Outcome Measures

Photoreceptor layer (PRL) and retinal pigment epithelium-Bruch's membrane (RPE-BM) thicknesses.

Results

Among 36 897 participants included in the analysis, 1571 (4.3%) reported very severe periodontitis. Affected individuals were older, lived in areas of greater socioeconomic deprivation, and were more likely to be hypertensive, diabetic, and current smokers (all P < 0.001). On average, those with very severe periodontitis were hyperopic (0.05 ± 2.27 diopters) while those unaffected were myopic (-0.29 ± 2.40 diopters, P < 0.001). Following adjusted analysis, very severe periodontitis was associated with thinner PRL (-0.55 μm, 95% confidence interval [CI], -0.97 to -0.12; P = 0.022) but there was no difference in RPE-BM thickness (0.00 μm, 95% CI, -0.12 to 0.13; P = 0.97). The association between PRL thickness and very severe periodontitis was modified by age (P < 0.001). Stratifying individuals by age, thinner PRL was seen among those aged 60 to 69 years with disease (-1.19 μm, 95% CI, -1.85 to -0.53; P < 0.001) but not among those aged < 60 years.

Conclusions

Among those with no known eye disease, very severe periodontitis is statistically associated with a thinner PRL, consistent with incipient AMD. Optimizing oral hygiene may hold additional relevance for people at risk of degenerative retinal disease.

Financial Disclosures

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Association between Oral Active-Matrix Metalloproteinase-8 Levels and Subretinal Fibrosis among Wet Age-Related Macular Degeneration Patients

PURPOSE

Periodontitis causes low-grade systemic inflammation and has been associated with elevated active-matrix metalloproteinase (aMMP-8) levels, blood-ocular barrier breakdown and a risk of wet age-related macular degeneration. To assess the association between aMMP-8 levels and macular status among patients with wet age-related macular degeneration (AMD).

METHODS

Patients on anti-VEGF treatment for wet AMD were enrolled for oral aMMP-8 rinse test in Mehiläinen Private Hospital, Helsinki, Finland. Macular status was examined from spectral-domain optical coherence tomography (SD-OCT) scans by a medical retina specialist and aMMP-8 levels were analyzed with chairside point-of-care oral rinse (PerioSafe®) test and real-time quantitated by a dentist using the ORALyzer®- reader with a 10 ng/ml cut-off for aMMP-8 activity.

RESULTS

Elevated aMMP-8 levels were found in 10 out of 32 patients. Age, gender, anti-VEGF (bevacizumab or aflibercept) distribution, cumulative number of anti-VEGF injections and treatment interval were comparable between patients with aMMP-8 levels below and above the point-of-care level. Macular status differed in regard to aMMP-8 activity; among patients with aMMP-8 levels below the point-of-care subretinal fibrosis was found in 6 out of 22 eyes, whereas among patients with aMMP-8 levels above the point-of-care subretinal fibrosis was found in 8 out of 10 eyes (p = 0.005). Respectively, the mean thickness of subretinal fibrosis at fovea was 19.5 ± 44.1 and 92.3 ± 78.3 µm (p = 0.018). No differences were found in the presence and in the area of geographic atrophy, or fluid distribution, whereas thicknesses of serous pigment epithelial detachment (65.5 ± 99.5 and 12.9 ± 27.9 µm, p = 0.038) and neuroretina (204.2 ± 57.8 µm and 143.0 ± 43.7 µm, p = 0.006) were greater in the eyes of patients with physiological aMMP-8 levels compared to those with elevated aMMP-8 levels.

CONCLUSION

Elevated aMMP-8 levels may account for subretinal fibrosis formation in wet AMD.

Epidemiology of geographic atrophy and its precursor features of intermediate age-related macular degeneration

Globally age-related macular degeneration (AMD) is a leading cause of blindness with a significant impact on quality of life. Geographic atrophy (GA) is the atrophic late form of AMD and its prevalence increases markedly with age with around 1 in 5 persons aged 85 and above having GA in at least one eye. Bilateral GA leads to severe visual impairment thus posing a significant burden on patients, careers and health providers. The incidence and prevalence of GA varies across different geographic regions, with the highest rates in those of European ancestry. Although heterogeneity in definitions of GA and reporting strategy can explain some of the discrepancies, the data overall are consistent in showing a lower prevalence in other ethnicities such as those of Asian heritage. This is at present unexplained but thought to be due to the existence of protective factors such as differences in eye pigmentation, diet, environmental exposures and genetic variability. This review covers key aspects of the prevalence and incidence of the ocular precursor features of GA (large drusen, pigmentary abnormalities and reticular pseudo-drusen), the late stage of GA and factors that have been known to be associated with modifying risk including systemic, demographic, environment, genetic and ocular. Understanding the global epidemiology scenario is crucial for the prevention of and management of patients with GA.

Salivary Exosomes in Health and Disease: Future Prospects in the Eye

Exosomes are a group of vesicles that package and transport DNA, RNA, proteins, and lipids to recipient cells. They can be derived from blood, saliva, urine, and/or other biological tissues. Their impact on several diseases, such as neurodegenerative, autoimmune, and ocular diseases, have been reported, but not fully unraveled. The exosomes that are derived from saliva are less studied, but offer significant advantages over exosomes from other sources, due to their accessibility and ease of collection. Thus, their role in the pathophysiology of diseases is largely unknown. In the context of ocular diseases, salivary exosomes have been under-utilized, thus creating an enormous gap in the literature. The current review discusses the state of exosomes research on systemic and ocular diseases and highlights the role and potential of salivary exosomes as future ocular therapeutic vehicles.

Association between periodontitis and blood-ocular barrier disruption

Purpose

Periodontitis causes low-grade systemic inflammation e.g., through circulatory periodontal endotoxins, and it has been associated with cardiovascular morbidity and wet age-related macular degeneration.

Methods

To assess the association between clinical severity of periodontitis and aqueous flare levels in the eyes. Patients with periodontitis (N = 15) who underwent periodontal treatment by a specialized dentist between the years 2020 and 2021 at the Chin and Mouth Disease Unit, Kymenlaakso Central Hospital, Kotka, Finland were enrolled. Aqueous flare levels, a surrogate marker for blood-aqueous and blood-retinal-barrier disruption, were measured using Laser Flare Meter (FM-600, Kowa Company, Ltd., Nagoya, Japan) before and right after the periodontal treatment and at 3 months. The number of teeth, periodontal probing depth (PPD), periodontal pathogens and antimicrobial treatment were recorded.

Results

At baseline, aqueous flare levels correlated with the number of clinically-relevant PPD (>5 mm) pockets (R = 0.789, P < 0.001) and inversely correlated with the number of teeth (R = −0.587, P = 0.035). At baseline, aqueous flare levels were 15.39 ± 13.24 photon units (pu)/ms among patients with periodontal pathogens, compared with 3.29 ± 1.67 pu/ms among those without any peridontal pathogens in PCR ( P = 0.018). At 3 months compared to baseline values, aqueous flare levels were reduced to <50% from baseline among 6 patients (40%), whereas the levels increased to >200% from baseline in 1 patient (7%) (repeated measures ANOVA, P < 0.026).

Conclusions

Poor periodontal status was associated with blood-ocular-barrier breakdown. These findings could expand our understanding of the potential mechanisms and therapeutic targets against retinal vascular diseases and systemic comorbidities in patients with periodontitis.

Evaluation of an Oral Care Program to Improve the Oral Health of Home-Dwelling Older People

The aim of this study was to evaluate the impact of the implementation of an Oral Care Program on home care nurses’ attitudes and knowledge about oral health (care) and the impact on older people’s oral health. A pre–post study, without a control group, was conducted. A preventive Oral Care Program (OCP) was designed, focusing on home care nurses and older people, in collaboration with dental hygienists. Implementation was measured with questionnaires at baseline and after 6 months for home care nurses; for older people, implementation was measured at baseline and after 3 months with the Oral Health Assessment Tool and a questionnaire about oral (self) care between January 2018 and September 2019. Although the study design has limitations, the oral health of older people improved significantly after 3 months and the OCP was most beneficial for people with full dentures. The OCP improved knowledge and attitude of home care nurses. The program fitted well with the daily work routines of home care nurses. Individual-centered care plans for older people, education of home care nurses and the expertise of the dental hygienists have added value in home care nursing. Future implementations should focus on older people with natural teeth.

Do Oral Pathogens Inhabit the Eye and Play a Role in Ocular Diseases?

Fascinatingly, the immune-privileged healthy eye has a small unique population of microbiota. The human microbiome project led to continuing interest in the ocular microbiome. Typically, ocular microflorae are commensals of low diversity that colonize the external and internal sites of the eye, without instigating any disorders. Ocular commensals modulate immunity and optimally regulate host defense against pathogenic invasion, both on the ocular surface and neuroretina. Yet, any alteration in this symbiotic relationship culminates in the perturbation of ocular homeostasis and shifts the equilibrium toward local or systemic inflammation and, in turn, impaired visual function. A compositional variation in the ocular microbiota is associated with surface disorders such as keratitis, blepharitis, and conjunctivitis. Nevertheless, innovative studies now implicate non-ocular microbial dysbiosis in glaucoma, age-related macular degeneration (AMD), uveitis, and diabetic retinopathy. Accordingly, prompt identification of the extra-ocular etiology and a methodical understanding of the mechanisms of invasion and host-microbial interaction is of paramount importance for preventative and therapeutic interventions for vision-threatening conditions. This review article aims to explore the current literature evidence to better comprehend the role of oral pathogens in the etiopathogenesis of ocular diseases, specifically AMD.

Periodontal and Peri-Implant Diseases and Systemically Administered Statins: A Systematic Review

Hyperlipidemia is a well-recognized risk factor for cardiovascular disease, which, in turn, acts as a contributory factor in periodontitis development. Periodontitis has been associated with benign tumors and cancers and withseveral disorders, including hyperlipidemia. Correspondingly, periodontal treatment may exert a positive effect on lipid metabolism, although opposite evidence has also been reported. As a counterpart, the therapy for hyperlipidemia, conventionally based on statins, has been proposed to positively affect periodontal conditions, mainly due to statin pleiotropic effects, reducing periodontal inflammation and promoting osseointegration. Therefore, the present systematic review aimed to evaluate, in subjects with untreated periodontitis and peri-implant disease (Population), the effect of routine systemically administered statins (Intervention), compared to non-statin use (Comparison), on periodontal parameters around natural teeth and implants (Outcome). Discordant results were found in periodontal parameters, and the current lack of such data related to peri-implant tissues and to alveolar bone loss highlights the need for further studies on the topic, potentially paving the way for a more comprehensive approach to periodontitis and peri-implantitis management. Indeed, the validation of the beneficial effect provided by systemically delivered statins on periodontal and peri-implant tissues may direct recall scheduling, predict response to therapy and, therefore, guide treatment strategies of periodontal and peri-implant treatments in statin users.

RISK OF AGE-RELATED MACULAR DEGENERATION IN PATIENTS WITH PERIODONTITIS: A Nationwide Population-Based Cohort Study

PURPOSE

Periodontitis is an inflammatory disease that results in loss of connective tissue and bone support. Evidence shows a possible relationship between periodontitis and age-related macular degeneration (AMD).

METHODS

This population-based cohort study was conducted using data from the National Health Insurance Research Database in Taiwan, with a 13-year follow-up, to investigate the risk of AMD in patients with periodontitis. The periodontitis cohort included patients with newly diagnosed periodontitis between 2000 and 2012. The nonperiodontitis cohort was frequency-matched with the periodontitis cohort by age and sex, with a sample size of 41,661 in each cohort.

RESULTS

Patients with periodontitis had an increased risk of developing AMD compared with individuals without periodontitis (5.95 vs. 3.41 per 1,000 person-years, adjusted hazard ratio = 1.58 [95% confidence interval, 1.46-1.70]). The risk of developing AMD remained significant after stratification by age (adjusted hazard ratio = 1.48 [1.34-1.64] for age <65 years and 1.76 [1.57-1.97] for age ≥65 years), sex (adjusted hazard ratio = 1.40 [1.26-1.55] for women and 1.82 [1.63-2.04] for men), and presence of comorbidity (adjusted hazard ratio = 1.52 [1.40-1.66] for with comorbidity and 1.92 [1.63-2.26] for without comorbidity). In addition, patients with periodontitis showed an increased incidence for both nonexudative type AMD (5.43 vs. 3.13 per 1,000 person-years) and exudative type AMD (0.52 vs. 0.28 per 1,000 person-years).

CONCLUSION

People with periodontitis could be at a greater risk of developing AMD than those without periodontitis. However, we need more evidence to support this association.

[Association between age-related macular degeneration and periodontal disease]

PURPOSE

To evaluate the association between age-related macular degeneration (AMD) and periodontal disease, two frequent conditions in the elderly, with some risk factors in common.

METHODS

Single center, pilot, case-control study performed in a center specialized in the diagnosis and management of AMD. Periodontal status was evaluated in 43 AMD patients and 19 controls. Fundus examination and a complete periodontal examination were performed in all subjects.

RESULTS

AMD patients have a greater percentage of 3-4mm clinical attachment loss compared to controls (47% vs. 38%, [P=0.039]). However, no significant difference was found between the groups with regard to the prevalence of severe periodontitis.

CONCLUSIONS

These results suggest an association between AMD and attachment loss characteristic of periodontal disease and support the need for larger prospective studies to elucidate the relationships between these 2 highly prevalent and potentially severe diseases.

Barriers and facilitators of oral health care experienced by nursing home staff

Objectives to explore attitudes, perceptions, and perceived barriers to and the perceived facilitators of daily oral health care and the actual daily oral health care performances among nursing home staff. Methods A mixed methods study in 21 nursing homes was completed; a) questionnaires for nursing staff and managers; b) focus group interviews with nursing staff. Results 409 (21%) questionnaires were completed by nursing staff and 14 focus group interviews organized. Conclusions attitude was not a barrier in this study, while oral care was not performed according to guidelines. Nursing staff reported a lack of products, while toothbrushes are available. The most frequently mentioned barriers were lack of support of dental staff, oral care for clients with cognitive impairment, and a lack of education. Increasing facilitators could be; more (practical) education combined with tailored advice from internal dental staff. Where and on whom will the research have an impact? Nursing home staff, nursing home organizations/ managers and dental professionals working in nursing homes.

Association between age-related macular degeneration and periodontal and peri-implant diseases: a systematic review

The aim of the present systematic review was to assess the association between age-related macular degeneration (AMD) and periodontal and peri-implant diseases. The focused question was 'Is there a relationship between AMD and periodontal and peri-implant diseases?' Indexed databases were searched up to and including May 2020 to identify pertinent original studies. The Cochrane Collaboration's tool was used to assess the risk of bias. Five observational cohort studies were included that assessed the association between AMD and periodontitis. The number of patients with and without AMD ranged between 54 and 90 and 1697 and 12,171 individuals, respectively. Examiner blinding to the study groups was performed in 1 of the 5 studies. None of the studies were power adjusted. Scrutiny of studies showed that all 5 studies included in the present systematic review had a high risk of bias. Results from all studies reported a direct association between AMD and periodontitis. No studies assessed the association between AMD and peri-implant diseases. The association between AMD and periodontal and peri-implant diseases remains debatable. Further well-designed and power-adjusted studies are needed to determine whether or not a 'true' association exists between AMD and periodontal and peri-implant diseases.

Incomplete response to Anti-VEGF therapy in neovascular AMD: Exploring disease mechanisms and therapeutic opportunities

Intravitreal anti-vascular endothelial growth factor (VEGF) drugs have revolutionized the treatment of neovascular age-related macular degeneration (NVAMD). However, many patients suffer from incomplete response to anti-VEGF therapy (IRT), which is defined as (1) persistent (plasma) fluid exudation; (2) unresolved or new hemorrhage; (3) progressive lesion fibrosis; and/or (4) suboptimal vision recovery. The first three of these collectively comprise the problem of persistent disease activity (PDA) in spite of anti-VEGF therapy. Meanwhile, the problem of suboptimal vision recovery (SVR) is defined as a failure to achieve excellent functional visual acuity of 20/40 or better in spite of sufficient anti-VEGF treatment. Thus, incomplete response to anti-VEGF therapy, and specifically PDA and SVR, represent significant clinical unmet needs. In this review, we will explore PDA and SVR in NVAMD, characterizing the clinical manifestations and exploring the pathobiology of each. We will demonstrate that PDA occurs most frequently in NVAMD patients who develop high-flow CNV lesions with arteriolarization, in contrast to patients with capillary CNV who are highly responsive to anti-VEGF therapy. We will review investigations of experimental CNV and demonstrate that both types of CNV can be modeled in mice. We will present and consider a provocative hypothesis: formation of arteriolar CNV occurs via a distinct pathobiology, termed neovascular remodeling (NVR), wherein blood-derived macrophages infiltrate the incipient CNV lesion, recruit bone marrow-derived mesenchymal precursor cells (MPCs) from the circulation, and activate MPCs to become vascular smooth muscle cells (VSMCs) and myofibroblasts, driving the development of high-flow CNV with arteriolarization and perivascular fibrosis. In considering SVR, we will discuss the concept that limited or poor vision in spite of anti-VEGF may not be caused simply by photoreceptor degeneration but instead may be associated with photoreceptor synaptic dysfunction in the neurosensory retina overlying CNV, triggered by infiltrating blood-derived macrophages and mediated by Müller cell activation Finally, for each of PDA and SVR, we will discuss current approaches to disease management and treatment and consider novel avenues for potential future therapies.

Temporal Trends over a Decade in Serious Vision Impairment in a Large, Nationally Representative Population-based Sample of Older Americans: Gender, Cohort and Racial/Ethnic Differences

Purpose: The objectives of this study are:1)To identify temporal trends in the age-sex-race/ethnicity adjusted prevalence of vision impairment among Americans aged 65+ from 2008-2017; To determine if these temporal trends in vision impairment differ by 2)gender and age cohort, and 3)race/ethnicity, and; 4)To investigate if improvements in cohort educational attainment partially attenuate these trends.Methods: Secondary analysis of 10 years of annual nationally-representative data from the American Community Survey with 5.4 million community-dwelling and institutionalized older adults aged 65+. The question on vision impairment was "Is this person blind or does he/she have serious difficulty seeing even when wearing glasses?".Results: The prevalence of serious vision impairment in the US population aged 65+ declined from 8.3% to 6.6% between 2008 and 2017. There would have been an additional 848,000 older Americans with serious vision impairment in 2017 if rates had remained at the 2008 level. After age, sex and race/ethnicity were controlled, women had a 2.1% per year decline in the odds of vision impairment (OR = 0.979; CI = 0.977, 0.980), which represents a 21% decline over the decade, and men had a 9% decline over the decade (OR = 0.991; CI = 0.989, 0.993). Adjusting for education attenuated the decade decline among women, reducing it to 13%, and completely attenuated the decline among men. Most of the decline was among those aged 75+. Racial/ethnic disparities narrowed over the decade.Conclusion: Between 2008 and 2017, the prevalence of serious vision impairment among older Americans declined significantly, with steeper declines among African Americans and Hispanic Americans than among non-Hispanic White Americans.

Exacerbation of AMD Phenotype in Lasered CNV Murine Model by Dysbiotic Oral Pathogens

Emerging evidence underscores an association between age-related macular degeneration (AMD) and periodontal disease (PD), yet the biological basis of this linkage and the specific role of oral dysbiosis caused by PD in AMD pathophysiology remains unclear. Furthermore, a simple reproducible model that emulates characteristics of both AMD and PD has been lacking. Hence, we established a novel AMD+PD murine model to decipher the potential role of oral infection (ligature-enhanced) with the keystone periodontal pathogen Porphyromonas gingivalis, in the progression of neovasculogenesis in a laser-induced choroidal-neovascularization (Li-CNV) mouse retina. By a combination of fundus photography, optical coherence tomography, and fluorescein angiography, we documented inflammatory drusen-like lesions, reduced retinal thickness, and increased vascular leakage in AMD+PD mice retinae. H&E further confirmed a significant reduction of retinal thickness and subretinal drusen-like deposits. Immunofluorescence microscopy revealed significant induction of choroidal/retinal vasculogenesis in AMD+PD mice. qPCR identified increased expression of oxidative-stress, angiogenesis, pro-inflammatory mediators, whereas antioxidants and anti-inflammatory genes in AMD+PD mice retinae were notably decreased. Through qPCR, we detected Pg and its fimbrial 16s-RrNA gene expression in the AMD+PD mice retinae. To sum-up, this is the first in vivo study signifying a role of periodontal infection in augmentation of AMD phenotype, with the aid of a pioneering AMD+PD murine model established in our laboratory.

Immunological Aspects of Age-Related Macular Degeneration

Increasing evidence over the past two decades points to a pivotal role for immune mechanisms in age-related macular degeneration (AMD) pathobiology. In this chapter, we will explore immunological aspects of AMD, with a specific focus on how immune mechanisms modulate clinical phenotypes of disease and severity and how components of the immune system may serve as triggers for disease progression in both dry and neovascular AMD. We will briefly review the biology of the immune system, defining the role of immune mechanisms in chronic degenerative disease and differentiating from immune responses to acute injury or infection. We will explore current understanding of the roles of innate immunity (especially macrophages), antigen-specific immunity (T cells, B cells, and autoimmunity), immune amplifications systems, especially complement activity and the NLRP3 inflammasome, in the pathogenesis of both dry and neovascular AMD, reviewing data from pathology, experimental animal models, and clinical studies of AMD patients. We will also assess how interactions between the immune system and infectious pathogens could potentially modulate AMD pathobiology via alterations in in immune effector mechanisms. We will conclude by reviewing the paradigm of "response to injury," which provides a means to integrate various immunologic mechanisms along with nonimmune mechanisms of tissue injury and repair as a model to understand the pathobiology of AMD.

Possible Association of Periodontal Disease and Macular Degeneration: A Case-Control Study

Oral pathogens have been identified in bioptic specimens from Age-Related Macular Degeneration (ARMD) patients, and alveolar bone loss has been related to ARMD. Therefore, the possible association between ARMD and periodontal disease was investigated in the present case-control study, evaluating clinical and radiographic periodontal parameters, primarily, in cases vs. controls and, secondarily, in relation to ARMD risk factors, in cases, to highlight a possible pathogenic link between the disorders. Forty ARMD cases and 40 non-ARMD controls, matched for age (±3 years) and gender and homogeneous for ARMD risk factors, therefore comparable, underwent full-mouth periodontal charting, panoramic radiograph, and medical data, including ARMD risk factors, collection. Statistical analysis was conducted using the language R. Comparisons between groups were made using both traditional t-tests and Yuen’s test with bootstrap calibration. Enrolled subjects were ≥55 years old, and 50 females and 30 males were equally distributed among the two groups. No statistically significant difference was found in clinical and radiographic periodontal parameters in cases vs. controls. In the case group, no differences were found when relating the periodontal parameters to ARMD risk factors, except for Clinical Attachment Level values that were statistically significantly higher in hypertensive ARMD subjects. A possible association between periodontal disease and ARMD may be hypothesized in hypertensive ARMD subjects, with hypertension as a possible pathogenic link between the disorders.

Eye on the Enigmatic Link: Dysbiotic Oral Pathogens in Ocular Diseases; The Flip Side

Mouth and associated structures were regarded as separate entities from the rest of the body. However, there is a paradigm shift in this conception and oral health is now considered as a fundamental part of overall well-being. In recent years, the subject of oral-foci of infection has attained a resurgence in terms of systemic morbidities while limited observations denote the implication of chronic oral inflammation in the pathogenesis of eye diseases. Hitherto, there is a paucity for mechanistic insights underlying the reported link between periodontal disease (PD) and ocular comorbidities. In light of prevailing scientific evidence, this review article will focus on the understudied theme, that is, the impact of oral dysbiosis in the induction and/or progression of inflammatory eye diseases like diabetic retinopathy, scleritis, uveitis, glaucoma, age-related macular degeneration (AMD). Furthermore, the plausible mechanisms by which periodontal microbiota may trigger immune dysfunction in the Oro-optic-network and promote the development of PD-associated AMD have been discussed.

Periodontal Disease and Age-Related Macular Degeneration: A Meta-Analysis of 112,240 Participants

OBJECTIVE

Epidemiological studies have shown a correlation between periodontal disease (PD) and age-related macular degeneration (AMD). However, the results have been inconsistent, and no relevant meta-analysis has been performed on this topic. Hence, we performed a meta-analysis to evaluate whether the two diseases are related. Material and Methods. The PubMed, Embase, Cochrane Library, and Web of Science databases were searched up to April 20, 2020, for related articles. Two authors independently conducted literature screening and data extraction and then used the Stata 15.1 software to calculate the relative risk (RRs) and 95% confidence intervals (CIs) to assess the association between PD and AMD.

RESULTS

A total of 5 observational studies involving 112,240 participants and 5,005 AMD patients were included. The results of meta-analysis using the random-effects model showed that the incidence of AMD in PD patients was 1.35 times that of non-PD patients; the difference was statistically significant (RR = 1.35, 95%CI = 1.07-1.70, P = 0.011). Sensitivity analysis showed that the results were stable.

CONCLUSIONS

PD patients have a higher risk of AMD, but the causal relationship between PD and AMD has not been confirmed. Further research should be carried out to verify the exact relationship between the two.

Automated Process Incorporating Machine Learning Segmentation and Correlation of Oral Diseases with Systemic Health

Imaging fluorescent disease biomarkers in tissues and skin is a non-invasive method to screen for health conditions. We report an automated process that combines intraoral fluorescent porphyrin biomarker imaging, clinical examinations and machine learning for correlation of systemic health conditions with periodontal disease. 1215 intraoral fluorescent images, from 284 consenting adults aged 18-90, were analyzed using a machine learning classifier that can segment periodontal inflammation. The classifier achieved an AUC of 0.677 with precision and recall of 0.271 and 0.429, respectively, indicating a learned association between disease signatures in collected images. Periodontal diseases were more prevalent among males (p=0.0012) and older subjects (p=0.0224) in the screened population. Physicians independently examined the collected images, assigning localized modified gingival indices (MGIs). MGIs and periodontal disease were then cross-correlated with responses to a medical history questionnaire, blood pressure and body mass index measurements, and optic nerve, tympanic membrane, neurological, and cardiac rhythm imaging examinations. Gingivitis and early periodontal disease were associated with subjects diagnosed with optic nerve abnormalities (p<; 0.0001) in their retinal scans. We also report significant co-occurrences of periodontal disease in subjects reporting swollen joints (p=0.0422) and a family history of eye disease (p=0.0337). These results indicate cross-correlation of poor periodontal health with systemic health outcomes and stress the importance of oral health screenings at the primary care level. Our screening process and analysis method, using images and machine learning, can be generalized for automated diagnoses and systemic health screenings for other diseases.

Invasion of Human Retinal Pigment Epithelial Cells by Porphyromonas gingivalis leading to Vacuolar/Cytosolic localization and Autophagy dysfunction In-Vitro

Recent epidemiological  studies link Periodontal disease(PD) to age-related macular degeneration (AMD). We documented earlier that Porphyromonas gingivalis(Pg), keystone oral-pathobiont, causative of PD, efficiently invades human gingival epithelial and blood-dendritic cells. Here, we investigated the ability of dysbiotic Pg-strains to invade human-retinal pigment epithelial cells(ARPE-19), their survival, intracellular localization, and the pathological effects, as dysfunction of RPEs leads to AMD. We show that live, but not heat-killed Pg-strains adhere to and invade ARPEs. This involves early adhesion to ARPE cell membrane, internalization and localization of Pg within single-membrane vacuoles or cytosol, with some nuclear localization apparent. No degradation of Pg or localization inside double-membrane autophagosomes was evident, with dividing Pg suggesting a metabolically active state during invasion. We found significant downregulation of autophagy-related genes particularly, autophagosome complex. Antibiotic protection-based recovery assay further confirmed distinct processes of adhesion, invasion and amplification of Pg within ARPE cells. This is the first study to demonstrate invasion of human-RPEs, begin to characterize intracellular localization and survival of Pg within these cells. Collectively, invasion of RPE by Pg and its prolonged survival by autophagy evasion within these cells suggest a strong rationale for studying the link between oral infection and AMD pathogenesis in individuals with periodontitis.

Bruch's membrane pathology: A mechanistic perspective

Bruch's membrane, an extracellular matrix located between the retinal pigment epithelium and the choroid, plays a vital role as structural and functional support to the retinal pigment epithelium. Dysfunction of Bruch's membrane in both age-related macular degeneration and other ocular diseases is caused mostly by extracellular matrix degeneration, deposit formation, and angiogenesis. Although these factors are dealt in greater detail with respect to the cells that are degenerated such as the retinal pigment epithelium and the endothelial cells, the pathology involving the Bruch's membrane is often underrated. Since in most of the macular degenerations early degenerative changes are also observed in the Bruch's membrane, addressing only the cellular component without the underlying membrane will not yield an ideal clinical benefit. This review aims to discuss the factors and the mechanisms affecting the integrity of the Bruch's membrane, which would aid in developing an effective therapy for these pathologies.

Periodontal Diseases and Age-Related Macular Degeneration: Is There a Link? A Review

BACKGROUND

Age-related macular degeneration (AMD) induces irreversible loss of vision in older people. The exact physiopathology remains unclear, but numerous studies highlight the role of inflammation and multiple risk factors. Recent data show an altered periodontal condition subject to AMD. Periodontal diseases lead to the destruction of tooth-supporting tissues, mainly caused by the periodontal infection inducing a chronic inflammation. Periodontal diseases are known to be associated with several extraoral diseases such as diabetes, polyarthritis (rheumatoid arthritis), cardiovascular disease, and preeclampsia.

OBJECTIVES

To assess emerging evidence suggesting an association between periodontitis and AMD.

METHODS

To support this review, we performed a literature search using PubMed, Cochrane, and Google Scholar databases, completed by manual searches in periodontology journals. We included only the original studies published before July 2017 reporting data on periodontal diseases and AMD. No restrictions were made on the language.

RESULTS

Persons with AMD showed more periodontal diseases, fewer teeth, and more alveolar bone loss than those without AMD. Also, a significant association was observed between periodontal diseases and AMD, but only in the youngest individuals studied.

CONCLUSION

According to the studies included in this review, periodontal disease may be a plausible risk factor for AMD and may have a potential role in the earlier stages of this eye disease. Further studies should be encouraged for better understanding of this potential new relationship.

The association between periodontal disease and age-related macular degeneration in the Korea National health and nutrition examination survey: A cross-sectional observational study

Periodontal disease (PD) is associated with various systemic diseases. We investigated the association between PD and age-related macular degeneration (AMD).For this population-based, cross-sectional study, we enrolled 13,072 adults at least 40 years of age with gradable retinal fundus photographs and community periodontal index (CPI) data from the Korean National Health and Nutrition Examination Survey (KNHANES) (2008-2010 and 2012). Participants were divided into a middle age group (age ≤62 years) and old age group (age >62 years). PD was divided into 2 categories of mild and severe. Logistic regression analysis was used to evaluate the association between PD and AMD (early and late).The prevalence of PD and AMD in the study population was 37.4% ± 0.8% and 5.6% ± 0.2%, respectively. Overall, there was no significant difference in the proportion of participants with PD between those with and without AMD. Only participants with AMD in the middle age group had more any PD than those without AMD (P = 0.031). Multivariate logistic regression model after adjusting for all confounding factors showed that PD was not significantly associated with AMD (odds ratio [OR] 1.03, 95% confidence interval [CI] 0.86-1.22). However, according to degree of PD, participants with severe PD in the middle age group were 1.61 times more likely to have AMD (OR 1.61, 95% CI 1.02-2.54).Our data, collected from an Asian population, showed that only severe PD is independently associated with AMD in individuals aged 62 years or younger.

Potential relationship between periodontal diseases and eye diseases

Periodontal diseases are inflammatory lesions initiated by oral bacteria and lead to the destruction of the supporting structures of the teeth (gingiva, periodontal ligament and alveolar bone) in susceptible patient. Via several biological mechanisms, periodontal diseases have been associated with multiple systemic diseases, such as rheumatoid arthritis, diabetes, cardiovascular diseases, Alzheimer's disease and adverse pregnancy outcomes. Similarly certain eye diseases have been associated with systemic diseases of the inflammatory pathway. We hypothesized that periodontal diseases are associated with eye diseases. Thus using literature data we find that several studies have reported that eye disorders are associated with the presence of periodontal diseases. But the mechanisms of this relationship are not clear. However the innate immune response involvement, the sharing of similar risk factors in pathogenesis and the changes of eye choroid thickness may be suggested as several hypotheses to explain this potential association.