Associated depression in pseudophakic patients with intraocular lens with and without chromophore

[Blue light and intraocular lenses (IOLs): Beliefs and realities]

The first intraocular lenses (IOLs) used for cataract surgery transmitted both ultraviolet (UV) radiation and visible light to the retina. Colorless UV-blocking IOLs were introduced and rapidly adopted in the 1980s. Yellow-tinted blue-blocking (also known as blue-filtering) IOLs were marketed in the early 1990s. Blue-blocking IOLs were intended to simulate age-related crystalline lens yellowing to reduce the cyanopsia that some patients experienced after cataract surgery. When blue-filtering IOLs were introduced in North America, however, blue-blocking chromophores were advocated as a way to protect patients from age-related macular degeneration (AMD) despite the lack of evidence that normal environmental light exposure causes AMD. The "blue light hazard" is a term that describes the experimental finding that acute, abnormally intense light exposures are potentially more phototoxic to the retina when short rather than long wavelengths are used. Thus, in brief exposures to intense light sources such as welding arcs, ultraviolet radiation is more hazardous than blue light, which is more hazardous than longer wavelength green or red light. International commissions have cautioned that the blue light hazard does not apply to normal indoor or outdoor light exposures. Nonetheless, the hazard is used for commercial purposes to suggest misleadingly that ambient environmental light can cause acute retinal phototoxicity and increase the risk of AMD. Very large epidemiological studies show that blue-blocking IOLs do not reduce the risk or progression of AMD. Additionally, blue-filtering IOLs or spectacles cannot decrease glare disability, because they decrease image and glare illuminance in the same proportion. Blue light is essential for older adults' scotopic photoreception needed to reduce the risk of nighttime falling and related injuries. It is also critical for circadian photoreception that is essential for good health, sleep and cognitive performance. Unfortunately, age-related pupillary miosis, retinal rod and ganglion cell photoreceptor degeneration and decreased outdoor activity all reduce the amount of healthful blue light available to older adults. Blue-restricting IOLs further reduce the available blue light at a time when older adults need it most. Patients and ophthalmologists are exposed to hypothesis-based advertisements for blue-filtering optical devices that suppress short wavelength light critical for vision in dim lighting and for good physical and mental health. Spectacle and intraocular lens selections should be based on scientific fact, not conjecture. Ideal IOLs should improve photoreception rather than limit it permanently. Practice efficiency, surgical convenience and physician-manufacturer relationships may eliminate a patient's opportunity to choose between colorless blue-transmitting IOLs and yellow-tinted, blue-restricting IOLs. Cataract surgeons ultimately determine whether their patients have the opportunity to make an informed choice about their future photoreception.

Content, Readability, and Accountability of Online Health Information for Patients Regarding Blue Light and Impact on Ocular Health

Objective To evaluate the quality and readability of online health content regarding the ocular health effects of blue light. Methods Five commercial and five non-commercial websites with content regarding the ocular effect of blue light were examined. Quality evaluations were conducted using a 14-question assessment composed by the authors and the 16-question DISCERN instrument. Website accountability was evaluated via the Journal of the American Medical Association (JAMA) benchmarks. Readability was determined using an online tool (Readable). Correlational and comparative analyses were conducted where appropriate. Results The average questionnaire score was 84 (standard deviation [SD] ± 17.89, 95% confidence interval [CI] 77.32-90.68) out of 136 points (61.8%). Significant differences in quality were identified between websites (p = 0.02), with Healthline achieving the highest score. Compared to commercial websites, non-commercial websites trended toward having significantly higher median questionnaire scores (p = 0.06). Zero websites achieved all four JAMA benchmarks. The average reading grade level of content was 10.43 (SD ± 1.15, 95% CI 9.60 - 11.25), with differences between websites trending toward significance (p = 0.09). There was no correlation between resource readability and quality (ρ = 0.28; p = 0.43) or accountability (ρ = 0.47; p = 0.17). Conclusions There remain substantial deficiencies in the quality, accountability, and readability of online content concerning the effect of blue light on ocular health. Clinicians and patients must recognize such issues when recommending and consuming these resources.

The Blue Light Hazard Versus Blue Light Hype

PURPOSE

The blue light hazard is the experimental finding that blue light is highly toxic to the retina (photic retinopathy), in brief abnormally intense exposures, including sungazing or vitreoretinal endoillumination. This term has been misused commercially to suggest, falsely, that ambient environmental light exposure causes phototoxicity to the retina, leading to age-related macular degeneration (AMD). We analyze clinical, epidemiologic, and biophysical data regarding blue-filtering optical chromophores.

DESIGN

Perspective.

METHODS

Analysis and integration of data regarding the blue light hazard and blue-blocking filters in ophthalmology and related disciplines.

RESULTS

Large epidemiologic studies show that blue-blocking intraocular lenses (IOLs) do not decrease AMD risk or progression. Blue-filtering lenses cannot reduce disability glare because image and glare illumination are decreased in the same proportion. Blue light essential for optimal rod and retinal ganglion photoreception is decreased by progressive age-related crystalline lens yellowing, pupillary miosis, and rod and retinal ganglion photoreceptor degeneration. Healthful daily environmental blue light exposure decreases in older adults, especially women. Blue light is important in dim environments where inadequate illumination increases risk of falls and associated morbidities.

CONCLUSIONS

The blue light hazard is misused as a marketing stratagem to alarm people into using spectacles and IOLs that restrict blue light. Blue light loss is permanent for pseudophakes with blue-blocking IOLs. Blue light hazard misrepresentation flourishes despite absence of proof that environmental light exposure or cataract surgery causes AMD or that IOL chromophores provide clinical protection. Blue-filtering chromophores suppress blue light critical for good mental and physical health and for optimal scotopic and mesopic vision.

Effect of Blue Light-Filtering Intraocular Lenses on Insomnia After Cataract Surgery: A Nationwide Cohort Study With 10-Year Follow-up

PURPOSE

To compare the incidence of clinically diagnosed insomnia after cataract surgery in pseudophakic eyes with blue light-filtering intraocular lenses (BF-IOLs) and non-BF-IOLs.

DESIGN

Nationwide cohort study using the Taiwan National Health Insurance Research Database.

METHODS

We enrolled 171,415 patients who underwent cataract surgery in both eyes between 2008 and 2013 and followed them till 2018. Propensity score matching (PSM) was used to balance the baseline characteristics between the 2 IOL groups. The Cox model and cause-specific hazard model were used to estimate the hazard ratios (HRs) and subdistribution hazard ratio (SHR).

RESULTS

Overall, 19,604 (11.4%) and 151,811 (88.6%) patients had BF-IOL and non-BF-IOL implants, respectively. The BF-IOL group tended to be younger and had fewer chronic diseases. Within a mean follow-up period of 6.2 years, the incidence rates of insomnia (per 100 person-years) in the BF-IOL and non-BF-IOL groups were 2.97 and 3.21, respectively. There was no significant difference in the incidence rate of insomnia between the 2 IOL groups after treating all-cause mortality as a competing risk (SHR 0.98, 95% CI 0.95-1.01) and after PSM (HR 0.97, 95% CI 0.92-1.01), respectively. Subgroup analysis revealed no significant difference in the insomnia rate between the 2 IOL groups for various age groups, 2 sex groups, and men with and without benign prostatic hyperplasia.

CONCLUSION

In Taiwan, the use of a BF-IOL for up to 10 years had no apparent disadvantage over non-BF-IOLs with respect to insomnia.

Protector role of intraocular lenses under artificial light conditions

INTRODUCTION

The aim of this work is to analyse, in an in vitro model, the possible protective effects of ultraviolet- (UV-) or UV/ blue-filtering intraocular lens (IOLs) under LED lighting conditions.

METHODS

10 models of IOLs were evaluated. Light transmission spectrum was recorded from 300 to 800 nm, in steps of 1 nm. Photodamage in vitro model was induced in ARPE-19 cells by blue LED light (465-475 nm). Changes in cell viability and oxidative stress variables were studied to assess the protective effect of IOLs.

RESULTS

UV/blue-filtering IOLs models block blue light spectrum in different proportion and UV-filtering IOLs blocking wavelength below 400 nm. However, in vitro study under blue LED light exposure does not show protective effects related with mitochondrial dysfunction and oxidative stress of UV/blue-filtering IOLs.

CONCLUSIONS

The current in vitro study suggest that UV/blue filtering IOLs are not useful in terms of photoprotection in artificial light conditions. The results obtained indicate that it is needed to give attention to other IOLs parameters besides the type of filter, as it seems they could have influence also protective role.

Association between conventional or blue-light-filtering intraocular lenses and survival in bilateral cataract surgery patients

Circadian rhythms regulate adaptive alterations in mammalian physiology and are maximally entrained by the short wavelength blue spectrum; cataracts block the transmission of light, particularly blue light. Cataract surgery is performed with two types of intraocular lenses (IOL): (1) conventional IOL that transmit the entire visible spectrum and (2) blue-light-filtering (BF) IOL that block the short wavelength blue spectrum. We hypothesized that the transmission properties of IOL are associated with long-term survival. This retrospective cohort study of a 15-hospital healthcare system identified 9,108 participants who underwent bilateral cataract surgery; 3,087 were implanted with conventional IOL and 6,021 received BF-IOL. Multivariable Cox proportional hazards models that included several a priori determined subgroup and sensitivity analyses yielded estimates supporting that conventional IOL compared with BF-IOL may be associated with significantly reduced risk of long-term death. Confirming these differences and identifying any potential causal mechanisms await the conduct of appropriately controlled prospective translational trials.

•

Risk of all-cause mortality in 9,108 patients after bilateral cataract surgery

•

Comparison of conventional intraocular lenses to blue-light-filtering intraocular lenses

•

Conventional lenses that transmit the entire visible spectrum may improve survival

•

Glaucoma patients particularly may benefit from conventional intraocular lenses

Blue light filtered white light induces depression-like responses and temporary spatial learning deficits in rats

OBJECTIVES

Ambient light has a vital impact on mood and cognitive functions. Blue light has been previously reported to play a salient role in the antidepressant effect via melanopsin. Whether blue light filtered white light (BFW) affects mood and cognitive functions remains unclear. The present study aimed to investigate whether BFW led to depression-like symptoms and cognitive deficits including spatial learning and memory abilities in rats, and whether they were associated with the light-responsive function in retinal explants.

METHODS

Male Sprague-Dawley albino rats were randomly divided into 2 groups (n = 10) and treated with a white light-emitting diode (LED) light source and BFW light source, respectively, under a standard 12 : 12 h L/D condition over 30 days. The sucrose consumption test, forced swim test (FST) and the level of plasma corticosterone (CORT) were employed to evaluate depression-like symptoms in rats. Cognitive functions were assessed by the Morris water maze (MWM) test. A multi-electrode array (MEA) system was utilized to measure electro-retinogram (ERG) responses induced by white or BFW flashes.

RESULTS

The effect of BFW over 30 days on depression-like responses in rats was indicated by decreased sucrose consumption in the sucrose consumption test, an increased immobility time in the FST and an elevated level of plasma CORT. BFW led to temporary spatial learning deficits in rats, which was evidenced by prolonged escape latency and swimming distances in the spatial navigation test. However, no changes were observed in the short memory ability of rats treated with BFW. The micro-ERG results showed a delayed implicit time and reduced amplitudes evoked by BFW flashes compared to the white flash group.

CONCLUSIONS

BFW induces depression-like symptoms and temporary spatial learning deficits in rats, which might be closely related to the impairment of light-evoked output signals in the retina.