Herpetic eye attacks: variability of circannual rhythms

Programmed ageing: decline of stem cell renewal, immunosenescence, and Alzheimer's disease

The characteristic maximum lifespan varies enormously across animal species from a few hours to hundreds of years. This argues that maximum lifespan, and the ageing process that itself dictates lifespan, are to a large extent genetically determined. Although controversial, this is supported by firm evidence that semelparous species display evolutionarily programmed ageing in response to reproductive and environmental cues. Parabiosis experiments reveal that ageing is orchestrated systemically through the circulation, accompanied by programmed changes in hormone levels across a lifetime. This implies that, like the circadian and circannual clocks, there is a master 'clock of age' (circavital clock) located in the limbic brain of mammals that modulates systemic changes in growth factor and hormone secretion over the lifespan, as well as systemic alterations in gene expression as revealed by genomic methylation analysis. Studies on accelerated ageing in mice, as well as human longevity genes, converge on evolutionarily conserved fibroblast growth factors (FGFs) and their receptors, including KLOTHO, as well as insulin-like growth factors (IGFs) and steroid hormones, as key players mediating the systemic effects of ageing. Age-related changes in these and multiple other factors are inferred to cause a progressive decline in tissue maintenance through failure of stem cell replenishment. This most severely affects the immune system, which requires constant renewal from bone marrow stem cells. Age-related immune decline increases risk of infection whereas lifespan can be extended in germfree animals. This and other evidence suggests that infection is the major cause of death in higher organisms. Immune decline is also associated with age-related diseases. Taking the example of Alzheimer's disease (AD), we assess the evidence that AD is caused by immunosenescence and infection. The signature protein of AD brain, Aβ, is now known to be an antimicrobial peptide, and Aβ deposits in AD brain may be a response to infection rather than a cause of disease. Because some cognitively normal elderly individuals show extensive neuropathology, we argue that the location of the pathology is crucial - specifically, lesions to limbic brain are likely to accentuate immunosenescence, and could thus underlie a vicious cycle of accelerated immune decline and microbial proliferation that culminates in AD. This general model may extend to other age-related diseases, and we propose a general paradigm of organismal senescence in which declining stem cell proliferation leads to programmed immunosenescence and mortality.

Seasonal Variation and Trend of Intraocular Pressure Decrease Over a 20-Year Period in Normal-Tension Glaucoma Patients

PURPOSE

To investigate the trend of seasonal variation of intraocular pressure (IOP) in patients with normal-tension glaucoma over a 20-year period by retrospectively analyzing the Kyoto Prefectural University of Medicine Glaucoma Registry database as real-world data.

DESIGN

Retrospective cohort study.

METHODS

Data points (n = 49,007) were extracted retrospectively from the medical records of 1774 patients with normal-tension glaucoma (665 male patients and 1109 female patients; mean ± SD age was 59.8 ± 14.4 years; and mean ± SD observation period was 5.6 ± 4.4 years) seen over the 20-year period. We first calculated the mean IOP from all available data of each month from January 1997 through December 2016. The data were then categorized into 5 groups of 4 consecutive years each (1997-2000, 2001-2004, 2005-2008, 2009-2012, and 2013-2016) and the mean IOP of each month within the group was calculated. Seasonal variations of IOP over the 20-year study period and in the 5 consecutive groups were then investigated via nonlinear multiple regression analysis.

RESULTS

A continuous decrease of IOP was detected throughout the 20-year period (P < .001), with distinct seasonal variation. The annual mean ± SD IOP was highest (13.9 ± 2.7 mm Hg) in the oldest group (1997-2000), with a gradual decrease in each subsequent group, finally becoming lowest (12.3 ± 2.7 mm Hg) in the most recent group (2013-2016) (P < .001), and all of them were accompanied by distinct seasonal variation (P < .001).

CONCLUSIONS

Based on the Kyoto Prefectural University of Medicine Glaucoma Registry real-world longitudinal data, our findings revealed a continuous decrease and distinct seasonal variation of IOP in patients with normal-tension glaucoma throughout the 20-year study period.

Seasonality of Acute Retinal Necrosis

Purpose

To study the seasonal variability in the occurrence of acute retinal necrosis (ARN) in a series of polymerase chain reaction (PCR)-positive patients.

Methods

Consecutive patients clinically diagnosed with ARN and a positive PCR result of aqueous humor during a seven-year period were studied retrospectively. Patients' demographics, causative viral agent(s), and the date of disease onset were extracted from medical records.

Results

Twenty eyes of 20 patients were enrolled; the mean age at presentation was 39.6 ± 14.4 (range, 6–62) years. Nine patients were female. The most common causative agent was varicella-zoster virus in 16 patients (80%), followed by herpes simplex virus in two patients (10%). The disease onset was in winter in 10 patients (50%), and the highest incidence was in February (five patients, 25%). The cumulative occurrence of ARN was significantly higher in the first half of the year (winter and spring) compared to the second half of the year (summer and fall) (P = 0.030). In general, seasons with a high incidence of ARN were preceded by cold seasons.

Conclusion

In our series, we observed seasonal variability in the incidence of ARN, with the highest incidence during winter and spring. However, further epidemiologic studies in different geographical areas are required to elucidate the true seasonal nature of ARN.

Do Season and Environment Have a Role in the Incidence of Anterior Uveitis Attacks?

PURPOSE

To investigate the seasonal influence on the incidence of uveitis attacks.

METHODS

An ecological study was designed including 731 uveitis attacks in 594 patients diagnosed at the eye emergency of a hospital in Madrid between 2014 and 2017. The incidence of uveitis attacks, B27+, and presumed herpetic attacks were calculated, and their correlations with seasonal and environmental variables in the same timeframe were analyzed. The analyzed variables were precipitation, barometric pressure, temperature, humidity, wind speed, global solar radiation, ultraviolet radiation, air pollution components (particulate matter and polluting gases), and the incidence of influenza.

RESULTS

The incidence of attacks was significantly higher in the winter than in the autumn (p = .025). It showed a significant correlation to the number of rainy days per month (r = 0.612;p = .04), and the average wind speed (r = 0.469;p = .02) after Bonferroni correction.

CONCLUSION

Uveitis episodes happened more frequently under rainy and windy conditions. Most factors were not significantly correlated to attacks.

Climate and season: the effects on ophthalmic diseases

Seasonal changes and climate have a significant impact on human health. Diseases influenced by temperature and climate conditions are likely to undergo dynamic pattern shifts with consequent impact on human health. A number of infectious and non-infectious ophthalmic diseases are influenced by temperature and seasonality. Awareness of this is important from public and global health perspective in addition to resource allocation strategies. We examine the evidence for a seasonal pattern to ophthalmic diseases and assess the possible impact of climate change.

Association between unprotected ultraviolet radiation exposure and recurrence of ocular herpes simplex virus

Studies have suggested that exposure to ultraviolet (UV) light may increase risk of herpes simplex virus (HSV) recurrence. Between 1993 and 1997, the Herpetic Eye Disease Study (HEDS) randomized 703 participants with ocular HSV to receipt of acyclovir or placebo for prevention of ocular HSV recurrence. Of these, 308 HEDS participants (48% female and 85% white; median age, 49 years) were included in a nested study of exposures thought to cause recurrence and were followed for up to 15 months. We matched weekly UV index values from the National Oceanic and Atmospheric Administration to each participant's study center and used marginal structural Cox models to account for time-varying psychological stress and contact lens use and selection bias from dropout. There were 44 recurrences of ocular HSV, yielding an incidence of 4.3 events per 1,000 person-weeks. Weighted hazard ratios comparing persons with ≥8 hours of time outdoors to those with less exposure were 0.84 (95% confidence interval (CI): 0.27, 2.63) and 3.10 (95% CI: 1.14, 8.48) for weeks with a UV index of <4 and ≥4, respectively (ratio of hazard ratios = 3.68, 95% CI: 0.43, 31.4). Though results were imprecise, when the UV index was higher (i.e., ≥4), spending 8 or more hours per week outdoors was associated with increased risk of ocular HSV recurrence.

Efficacy of oral antiviral prophylaxis in preventing ocular herpes simplex virus recurrences in patients with and without self-reported atopy

PURPOSE

To compare the efficacy of oral antiviral prophylactic treatment for herpes simplex virus (HSV) recurrences in patients with and without self-reported atopy.

DESIGN

Retrospective cohort comparative study.

METHODS

setting: Cornea Service, Wills Eye Hospital. study population: Patients who presented with previously diagnosed ocular HSV between March 2003 and March 2004. From 244 patients invited, 54 patients (58 eyes) were included. One hundred and ninety patients were excluded according to exclusion criteria: no active episode during follow-up, immunosuppression, less than one year of follow-up, or previous history of penetrating keratoplasty. The Questionnaire regarding history of atopic disease, considers: presence of allergic rhinitis, asthma or atopic dermatitis, and chart review of ocular history. main outcome measures: Incidence of all types of HSV recurrences with and without antiviral prophylaxis within each group and between groups. HSV episodes were classified into infectious, inflammatory, and mixed for analysis.

RESULTS

Atopic/nonatopic (P value): mean follow-up without prophylaxis 8.1 (+/- 8.2)/7.3 years (+/- 8.6) (P = .71); mean follow-up with prophylaxis 2.9 (+/- 2.3)/2.6 years (+/- 2.2) (P = .51); the effect of prophylaxis significantly reduced the all recurrences in both groups except in the inflammatory recurrences in the atopic group and in the mixed recurrences in both groups. Prophylaxis decreased infectious episodes by 44% in nonatopic and 76% in atopics and decreased inflammatory manifestations by 69% in the nonatopic group and 8% in the atopic group.

CONCLUSION

Antiviral prophylaxis for HSV recurrences was more effective in reducing infections in atopics and less effective in reducing inflammatory episodes in atopics versus nonatopics.

Seasonal variation of Bell's palsy in Athens, Greece - a hospital-based retrospective evaluation over fifteen years

Epidemiological data on the incidence of Bell's palsy (BP) are conflicting. The aim of this retrospective study was to evaluate the variation of cases of BP acutely presented in the emergency room of our department over a 15-year period (January 1990 to December 2004). We examined the monthly and seasonal distribution of BPs among 36,312 patients who came to our emergency services and compared it with the assumed equal distribution of cases over the year (null hypothesis) using chi(2) techniques. During the observation period 1,252 of all patients (3.45%) presented due to BP. A decline during the summer was observed, in contrast to a peak documented during the autumn and winter. January and July were the months with the highest and lowest frequency of BP, respectively. Statistical analysis revealed a significantly different seasonal (chi(2) = 10.569; d.f. = 3; p = 0.014) and monthly (chi(2) = 25.445; d.f. = 11; p = 0.008) pattern of BP cases. The distribution of cases of BP shows a significant variation with a decline during the summer and an increase during the colder period of the year. A similar pattern has been described for reactivated herpetic ocular infections. Since a similar pathogenetic mechanism is regarded as the main cause of BP, the chronobiological aspects and the influence of meteorological factors on the reactivation of latent infections deserves further prospective evaluation.

Bilateral acute depigmentation of the iris

PURPOSE

To report on five cases of unusual bilateral stromal depigmentation of the iris and pigment dispersion masquerading as uveitis.

METHODS

We describe the clinical features of five consecutive patients who presented with acute depigmentation of the iris stroma between June and October 2003.

RESULTS

Four patients were female, one was male. Age at presentation ranged from 15 to 25 years. Presenting symptoms were sudden-onset ocular discomfort and red eye in four patients and change of eye color in one patient. All patients had bilateral involvement, with a symmetrical diffuse depigmentation of the iris stroma in three cases and patchy areas of iris depigmentation in two. Other common features were mild ciliary injection (seven eyes), Krukenberg spindle (seven eyes), circulating pigment in the anterior chamber (eight eyes), and heavy pigment deposition in the angle (ten eyes). No eyes had iris transillumination defects, inflammatory keratic precipitates or inflammatory cells in the anterior chamber. Systemic laboratory work-up was unrewarding in all cases, and PCR analysis of the aqueous humor for HSV1 and 2 was negative in one patient. Four patients were treated with a short course of topical corticosteroids and three with oral acyclovir. One patient was lost to follow-up. The remaining four patients were followed up for 6-19 months with a stable clinical picture.

CONCLUSION

In contrast to pigment dispersion syndrome, pigment seemed to be released from iris stroma in the five cases described here. Although patchy depigmentation of the iris resembled the lesions seen in herpetic iridocyclitis in two of the patients, symmetrical bilateral involvement and lack of intraocular inflammation were the differentiating features. The patients described here could represent a new entity or an unusual presentation of herpetic eye disease.

Herpes simplex virus epidemiology and ocular importance

PURPOSE

To review the changing epidemiology of herpes simplex disease and correlate it with the epidemiology of ocular herpes simplex disease.

METHOD

A review of pertinent reports in the world literature about the epidemiology of herpes simplex and specifically about ocular herpes simplex.

RESULTS

In developed countries, many individuals are reaching adolescence and adulthood without prior herpesvirus infection. Herpes simplex genital infection is increasing at a rapid rate in sexually active adolescents and adults, with about one in six adults now infected in the United States. Similar statistics are confirmatory worldwide in developed countries. Active herpes simplex infection is a risk factor for acquisition of human immunodeficiency virus. The Herpetic Eye Disease Study, as well as prior studies from Moorfields Eye Hospital and the Mayo Clinic in Rochester, Minnesota, provides us with the epidemiology of ocular herpes simplex. Recent studies suggest an older age of onset and perhaps overall more severe ocular disease as compared with the older literature.

CONCLUSIONS

Herpes simplex is a significant health concern at present with genital infections increasing in epidemic proportions. This is also reflected in a rise in the incidence of neonatal herpes. Herpes simplex virus type 1 (HSV-1) infection is being acquired for the first time in an older age group. A significant and increasing proportion of genital herpes is caused by HSV-1. Serologic studies are no longer as useful in distinguishing orofacial herpes from genital herpes. More acute retinal necrosis syndrome cases are associated with HSV-2. Speculation about the future of ocular herpes is made based on this changing epidemiology.