Preventing blindness and visual impairment in Europe: What do we have to do?

Circulating MicroRNAs as Biomarker for Vessel-Associated Retinal Diseases

INTRODUCTION

Vessel-associated retinal diseases are a major cause of blindness and severe visual impairment. The identification of appropriate biomarkers is of great importance to better anticipate disease progression and establish more targeted treatment options. MicroRNAs (miRNAs) are short, single-stranded, noncoding ribonucleic acids that are involved in the posttranscriptional regulation of gene expression through hybridization with messenger RNA. The expression of certain miRNAs can be different in patients with pathological processes and can be used for the detection and differentiation of various diseases. In this study, we investigate to what extent previously in vitro identified miRNAs are present as cell-free circulating miRNAs in the serum and vitreous of human patients with and without vessel-associated retinal diseases.

METHODS

Relative quantification by quantitative real-time polymerase chain reaction was used to analyze miRNA expression in patients with vessel-associated retinal diseases such as age-related macular degeneration (AMD), diabetic retinopathy (DR), and retinal vein occlusion compared with control patients.

RESULTS

In serum samples, miR-29a-3p and miR-192-5p showed increased expression in patients with neovascular AMD relative to control patients. Similarly, miR-335-5p, miR-192-5p, and miR-194-5p showed increased expression in serum from patients with proliferative DR. In vitreous samples, miR-100-5p was decreased in patients with proliferative DR. Differentially expressed miRNAs showed good diagnostic accuracy in receiver operating characteristic (ROC) and area under the ROC curve analysis.

CONCLUSION

The miRNAs investigated in this study may have the potential to serve as biomarkers for vessel-associated retinal diseases. Combining multiple miRNAs may enhance the predictive power of the analysis.

Prevalence of refractive errors in Hungary reveals three-fold increase in myopia

AIM

To examine the prevalence and composition of refractive errors in Hungary.

METHODS

Nationwide cross-sectional data collected between 2014 and 2019 were analysed from the Comprehensive Health Screening Program of Hungary, which provided spectacle dioptric power and autorefractometry data for 68 227 people (35 850 women and 32 377 men). Their age distribution, 18-99y, was similar to the national demographic distributions.

RESULTS

Of the total population, 16.50% of the refractive errors exhibited hyperopia, 40.05% emmetropia, and 43.45% myopia. Myopia was 3 times more frequent (58.7%) in younger ages (18-35y of age) compared to older age groups (19.4% of those 56-70y of age; P<0.001). High myopia showed a low prevalence (0.21%), and an increase parallel with ageing (r=0.716; P=0.009).

CONCLUSION

Myopia is the most frequent refractive error in Hungary. The prevalence of myopia is especially increased, up to 2-3 times, in the younger age groups. Nationwide actions need to be taken to reduce the onset of myopia and its associated consequences.

Time Trends of Etiologies of Blindness in Israel 2009-2020:Have Methods to Decrease Leading Causes of Blindness Been Exhausted?

PURPOSE

To perform a nationwide analysis of trends in the incidence of etiologies for legal blindness in Israel during 2009-2020, and to compare the results with those of the previous decade.

DESIGN

Descriptive, retrospective population-based trend study.

METHODS

Data were retrieved from the Israeli National Registry of the Blind during 2009-2020. Data obtained included demographics, years of registration, and causes. Primary and secondary outcomes were the incidence of new certified blindness cases and its comparison with that of the previous decade, respectively.

RESULTS

The age-standardized incidence rate of blindness in Israel decreased from 15.76 per 100,000 residents in 2009 to 11.83 in 2020, a 24.9% drop. The mean annual decline was evident until 2013 (P < .001, 6.15%), but subsequently flattened (P = .71, 0.42%). Age-related macular degeneration (AMD), glaucoma, optic atrophy, and cataract decreased until 2014, and reached a plateau that was maintained until the end of the study period. Diabetic retinopathy (DR) incidence rates diminished throughout the decade (P < .001, 9.2%), with attenuation of the rate of decline after 2014.

CONCLUSIONS

The impact of efforts to reduce the incidence of preventable causes of blindness may have nearly reached saturation for most of the leading causes of blindness in Israel, namely, AMD, glaucoma and cataract. The incidence of DR has been maintained; however, attenuation has been observed. New modalities to detect and treat these causes may have to emerge before a resurgence of improvement can occur.

Blindness and visual impairment in Central Europe

Purpose

To assess the prevalence and causes of visual impairment and blindness in a Central European country. The findings may have implications for the planning of further research and development of therapies in order to prevent blindness.

Setting

Department of Ophthalmology, Medical University of Graz, Austria.

Design

Retrospective, epidemiological study.

Methods

The database of the Main Confederation of Austrian Social Insurances was searched for patients with visual impairment, legal blindness or deaf-blindness. This database gathers data from patients of all insurance providers in the country who receive care due to visual impairment and blindness. To determine the prevalence of these conditions, the number of all entries recorded in February 2019 was evaluated. Additionally, all new entries between (January 1^st,) 2017, and (December 31^st,) 2018, were analysed for distinct characteristics, such as sex, the cause of blindness/visual impairment, and age. Since health care allowances can provide a considerable source of income (459.90€-936.90€ per month), good coverage of practically all patients who are blind and visually impaired in the country can be assumed.

Results

On February 2^nd, 2019, 17,730 patients with visual impairments, blindness or deaf-blindness were registered in Austria, resulting in a prevalence of these diagnoses of 0.2% in the country. During the observational period from 2017 to 2018, 4040 persons met the inclusion criteria. Of these, 2877 were female (65.3%), and 1527 were male (34.7%). The mean age was 75.7 ± 18.0 years (median 82). Most patients (n = 3675, 83.4%) were of retirement age, while 729 (16.6%) were working-age adults or minors. In total, an incidence of 25.0 (95% confidence limit (CL) 24.3–25.8) per 100,000 person-years was observed from 2017 to 2018. A higher incidence was observed for females (32.2, 95% CL 31.0–33.3) than for males (17.7, 95% CL 16.8–18.5). Incidences where higher for males in lower age groups (e.g. 10–14 years: rate ratio RR = 2.7, 95% CL 1.1–6.8), and higher for females in higher age groups (e.g. 70–74 years: RR = 0.6, 95% CL 0.5–0.8). In total, the most frequent diagnoses were macular degeneration (1075 persons, 24.4%), other retinal disorders (493 persons, 11.2%) and inherited retinal and choroidal diseases (IRDs) (186 persons, 4.2%). Persons with IRDs were significantly younger compared to persons with macular degeneration or retinal disorders (IRDs: median 57, range 2–96 vs 83, 5–98 and 82, 1–98 years, p<0.001). For persons of retirement age, macular degeneration, other retinal disorders and glaucoma were the three most frequent diagnoses. In contrast, among working-aged adults and children, IRDs were the leading cause of visual impairment and blindness (103 persons, 14.1%).

Conclusion

These data show that IRDs are the leading cause of blindness and visual impairment in working-aged persons and children in Austria. Thus, these findings suggest to draw attention to enhance further research in the fields of emerging therapies for IRDs.

The evaluation of a web-based tool for measuring the uncorrected visual acuity and refractive error in keratoconus eyes: A method comparison study

Purpose

To evaluate the outcome of a web-based digital assessment of visual acuity and refractive error, compared to a conventional supervised assessment, in keratoconus patients with complex refractive errors.

Material and methods

Keratoconus patients, aged 18 to 40, with a refractive error between -6 and +4 diopters were considered eligible. An uncorrected visual acuity and an assessment of refractive error was taken web-based (index test) and by manifest refraction (reference test) by an optometrist. Corrected visual acuity was assessed with the prescription derived from both the web-based tool and the manifest refraction. Non-inferiority was defined as the 95% limits-of-agreement (95%LoA) of the differences in spherical equivalent between the index and reference test not exceeding +/- 0.5 diopters. Agreement was assessed by a Bland-Altman analyses.

Results

A total of 100 eyes of 50 patients were examined. The overall mean difference of the uncorrected visual acuity measured -0.01 LogMAR (95%LoA:-0.63–0.60). The variability of the differences decreased in the better uncorrected visual acuity subgroup (95%LoA:-0.25–0.55). The overall mean difference in spherical equivalent between the index and reference test exceeded the non-inferiority margin: -0.58D (95%LoA:-4.49–3.33, P = 0.008). The mean differences for myopic and hyperopic subjects were 0.09 diopters (P = 0.675) and -2.06 diopters (P<0.001), respectively. The corrected visual acuities attained with the web-based derived prescription underachieved significantly (0.22±0.32 logMAR vs. -0.01±0.13 LogMAR, P <0.001).

Conclusions

Regarding visual acuity, the web-based tool shows promising results for remotely assessing visual acuity in keratoconus patients, particularly for subjects within a better visual acuity range. This could provide physicians with a quantifiable outcome to enhance teleconsultations, especially relevant when access to health care is limited. Regarding the assessment of the refractive error, the web-based tool was found to be inferior to the manifest refraction in keratoconus patients. This study underlines the importance of validating digital tools and could serve to increase overall safety of the web-based assessments by better identification of outlier cases.

Self-reported visual difficulties in Europe and related factors: a European population-based cross-sectional survey

PURPOSE

There is a relative paucity of self-reported vision problems data in European countries.

METHODS

In this context, we investigated self-reported vision problems through European Health Interview Survey 2, a cross-sectional European population survey based on a standardized questionnaire including 147 medical, demographic and socioeconomic variables applied to non-institutionalized individuals aged 15 years or more in 28 European countries, in addition to Iceland and Norway.

RESULTS

The survey included 311 386 individuals (54.18% women), with overall crude prevalence of self-reported vision problems of 2.07% [95% CI; 2.01-2.14]. Among them, 1.70 % [1.61-1.78] of men, 2.41% [2.31-2.51] of women and 4.71% [4.53-4.89] of individuals aged 60 or more reported to have a lot of vision problems or to be not able to see. The frequency of self-reported vision problems was the highest in Eastern European countries with values of 2.43% [2.30-2.56]. In multivariate analyses, limiting long-standing illness, depression, daily smoking, lack of physical activity, lower educational level and social isolation were associated with self-reported vision problems with ORs of 2.66 [2.42-2.92], 2.16 [2.01-2.32], 1.11 [1.01-1.23], 1.31 [1.21-1.42], 1.29 [1.19-1.40] and 1.45 [1.26-1.67], respectively, while higher income was associated with less self-reported vision problems with OR of 0.80 [0.73-0.86].

CONCLUSIONS

This study demonstrated inequalities in terms of prevalence of self-reported vision problems in Europe, with higher prevalence in Eastern European countries and among women and older individuals.

Microfluidic and Microscale Assays to Examine Regenerative Strategies in the Neuro Retina

Bioengineering systems have transformed scientific knowledge of cellular behaviors in the nervous system (NS) and pioneered innovative, regenerative therapies to treat adult neural disorders. Microscale systems with characteristic lengths of single to hundreds of microns have examined the development and specialized behaviors of numerous neuromuscular and neurosensory components of the NS. The visual system is comprised of the eye sensory organ and its connecting pathways to the visual cortex. Significant vision loss arises from dysfunction in the retina, the photosensitive tissue at the eye posterior that achieves phototransduction of light to form images in the brain. Retinal regenerative medicine has embraced microfluidic technologies to manipulate stem-like cells for transplantation therapies, where de/differentiated cells are introduced within adult tissue to replace dysfunctional or damaged neurons. Microfluidic systems coupled with stem cell biology and biomaterials have produced exciting advances to restore vision. The current article reviews contemporary microfluidic technologies and microfluidics-enhanced bioassays, developed to interrogate cellular responses to adult retinal cues. The focus is on applications of microfluidics and microscale assays within mammalian sensory retina, or neuro retina, comprised of five types of retinal neurons (photoreceptors, horizontal, bipolar, amacrine, retinal ganglion) and one neuroglia (Müller), but excludes the non-sensory, retinal pigmented epithelium.

National studies from the Netherlands and Finland and the impact of regulations on incidences of fireworks-related eye injuries

Fireworks-related eye injuries occur all over the world whenever fireworks are available for the public. The two prospective registers from Finland over 20 years and from the Netherlands over 10 years have tracked the effect of regulations, awareness, and safety campaigns. The incidence of fireworks-related injuries in these two countries has been reduced to about one half during the last 10 years through addressing the number of hours allowed for private fireworks, the use of safety glasses, awareness campaigns, and stricter regulations on fireworks available for purchase. Although the total number of injuries has decreased, the average severity of eye injuries in the Netherlands seems to have increased due to higher content of gunpowder in fireworks. Boys and young men are mainly affected as well as bystanders who account for more than half of fireworks-related eye injuries. More work on safety of fireworks is still needed through regulating private consumer use of fireworks, a challenge that lies ahead for ophthalmologic organizations worldwide, including the European Society of Ophthalmology (SOE), the International Council of Ophthalmology (ICO) and national societies. But every eye saved from severe injury is worth the effort.

[National studies from the Netherlands and Finland and the impact of regulations on incidences of fireworks-related eye injuries. German version]

Fireworks-related eye injuries occur all over the world whenever fireworks are available for the public. The two prospective registers from Finland over 20 years and from the Netherlands over 10 years have tracked the effect of regulations, awareness, and safety campaigns. The incidence of fireworks-related injuries in these two countries has been reduced to about one half during the last 10 years through addressing the number of hours allowed for private fireworks, the use of safety glasses, awareness campaigns, and stricter regulations on fireworks available for purchase. Although the total number of injuries has decreased, the average severity of eye injuries in the Netherlands seems to have increased due to higher content of gunpowder in fireworks. Boys and young men are mainly affected as well as bystanders who account for more than half of fireworks-related eye injuries. More work on safety of fireworks is still needed through regulating private consumer use of fireworks, a challenge that lies ahead for ophthalmologic organizations worldwide, including the European Society of Ophthalmology (SOE), the International Council of Ophthalmology (ICO) and national societies. But every eye saved from severe injury is worth the effort.