Blue light-filtering intraocular lenses and post-operative mood: a pilot clinical study

Depression and Eye Disease-A Narrative Review of Common Underlying Pathophysiological Mechanisms and their Potential Applications

Background: Depression has been shown to be associated with eye diseases, including dry eye disease (DED), cataracts, glaucoma, age-related macular degeneration (AMD), and diabetic retinopathy (DR). This narrative review explores potential pathophysiological connections between depression and eye disease, as well as its potential correlations with ocular parameters. Methods: A literature search was conducted in August 2022 in PUBMED, EMBASE, and PsycINFO. Published articles related to the subject were consolidated and classified according to respective eye diseases and pathophysiological mechanisms. Results: The literature reviewed suggests that common pathophysiological states like inflammation and neurodegeneration may contribute to both depression and certain eye diseases, while somatic symptoms and altered physiology, such as disruptions in circadian rhythm due to eye diseases, can also influence patients' mood states. Grounded in the shared embryological, anatomical, and physiological features between the eye and the brain, depression is also correlated to changes observed in non-invasive ophthalmological imaging modalities, such as changes in the retinal nerve fibre layer and retinal microvasculature. Conclusions: There is substantial evidence of a close association between depression and eye diseases. Understanding the underlying concepts can inform further research on treatment options and monitoring of depression based on ocular parameters.

The association between cataract surgery and mental health in older adults: a review

BACKGROUND

Although cataract surgery has been proposed as a potentially modifiable protective factor for enhancing emotional well-being in cataract patients, studies examining the relationship between anxiety or depression and cataract surgery have yielded inconsistent findings. This review summarizes existing evidence to establish whether cataract surgery is associated with depression and anxiety in older adults.

METHODS

A literature search was conducted across PubMed, Medline, Web of Science, and Embase databases. An initial screening by abstracts and titles was performed, followed by a review and assessment of the methodological quality of the relevant full papers, and final inclusion of 44 studies were deemed eligible for inclusion in this review.

RESULTS

Among 44 included studies, 36 studies (81.8%) were observational studies concerning the association of cataract surgery or cataracts with anxiety or depression, four studies (9.1%) were interventional studies, and four studies (9.1%) were reviews. Cataract surgery notably enhances the mental health of individuals with impaired vision. However, the multifaceted nature of psychological well-being, influenced by various factors, suggests that cataract surgery may not address all aspects comprehensively. Additionally, preoperative anxiety and depression significantly impact cataract surgery outcomes.

CONCLUSION

Vision impairment in older adults is closely associated with increased symptoms of depression and anxiety. While surgical intervention for cataracts improves these symptoms, it might be less effective for mental disorders with multifactorial causes. Notably, anxiety or depression poses challenges to successful preoperative and intraoperative cataract surgeries.

Sleep and mood changes in advanced age after blue-blocking (yellow) intra ocular lens (IOLs) implantation during cataract surgical treatment: a randomized controlled trial

OBJECTIVES

Both advanced age and depression are characterized by changes in sleep patterns. Light exposure is one of the main synchronizers of circadian cycles and influences sleep by inhibiting melatonin secretion, which is mostly sensitive to light of low wavelengths (blue). Blue-blocking (yellow) intraocular lenses (IOLs) have supplanted the usual UV-blocking (clear) IOLs during cataract surgery to prevent age-related macular degeneration, however, the impact of yellow IOLs on sleep and mood is unclear. The purpose of this study was to compare the effects of yellow and clear IOLs on sleep and mood in aged patients undergoing bilateral cataract surgery.

METHODS

A randomized controlled superiority study was conducted within three ophthalmic surgical wards in France. A total of 204 subjects (mean age 76.2 ± 7.5 years) were randomized into yellow or clear IOLs groups. Patients completed a sleep diary, the pictorial sleepiness scale and the Beck Depression Inventory (BDI) one week before and eight weeks after the last surgical procedure.

RESULTS

According to an Intent To Treat (ITT) analysis, no significant difference was found between yellow and clear IOLs groups regarding sleep time, sleep latency, total sleep duration, quality of sleep and BDI scores. The rate of patients whose BDI score increased at the cutoff score of ≥5 after surgery was significantly higher in the yellow IOL group (n = 11, 13.1%) compared with the clear IOL group (n = 4; 4.7%); p = 0.02.

CONCLUSIONS

Using yellow IOLs for cataract surgery doesn't significantly impact sleep but may induce mood changes in aging.

Electroencephalogram alertness responses to blue light stimulus in elderly people with cataract

Daytime blue light exposure can reduce fatigue and increase alertness in young healthy adults. Little is known of the daytime blue light influence on alertness in elders. A prospective with-in subject study was carried out in Peking University Third Hospital to evaluate the impact of cataract surgery on visual functions and the electroencephalogram alertness response to blue light stimulus before and after surgery. 14 participants diagnosed with age-related cataract were scheduled for monocular cataract surgery with ultraviolet-filtering intraocular lens (IOL) implantation. Best corrected visual acuity (BCVA), color discrimination and electroencephalogram results were measured before and after surgery. Exposure to blue light resulted in decreased delta (0.25-3.00 Hz) activity and increased beta (13.25-30.00 Hz) activity both before and after cataract surgery. Significant improvements in the BCVA and Farnsworth-Munsell-100-hue total error scores were found after cataract surgery. The partial error scores in the red-yellow, green blue-blue, and blue purple-purple red bands also showed significant differences, with the green blue-blue band showing the most obvious improvement. Day-time blue light stimulus can increase alertness in elderly people with significant cataracts. Cataract surgery with ultraviolet-filtering IOL implantation can increase light, particularly blue light transmittance. Opaque lens removal does not increase the alertness responses to blue light 1 day after surgery. Nevertheless, the increase in light especially blue light perception can be beneficial for the health of elder people in the long run.

Pupillary responses to short-wavelength light are preserved in aging

With aging, less blue light reaches the retina due to gradual yellowing of the lens. This could result in reduced activation of blue light-sensitive melanopsin-containing retinal ganglion cells, which mediate non-visual light responses (e.g., the pupillary light reflex, melatonin suppression, and circadian resetting). Herein, we tested the hypothesis that older individuals show greater impairment of pupillary responses to blue light relative to red light. Dose-response curves for pupillary constriction to 469-nm blue light and 631-nm red light were compared between young normal adults aged 21–30 years (n = 60) and older adults aged ≥50 years (normal, n = 54; mild cataract, n = 107; severe cataract, n = 18). Irrespective of wavelength, pupillary responses were reduced in older individuals and further attenuated by severe, but not mild, cataract. The reduction in pupillary responses was comparable in response to blue light and red light, suggesting that lens yellowing did not selectively reduce melanopsin-dependent light responses. Compensatory mechanisms likely occur in aging that ensure relative constancy of pupillary responses to blue light despite changes in lens transmission.

Ultraviolet or blue-filtering intraocular lenses: what is the evidence?

Cataract surgery was revolutionised by the introduction of modern intraocular lenses in the late 1940's. By the late 1960's to 1970's evidence had emerged that short-wavelength light caused phototoxicity at the retina and retinal pigment epithelium. By the early 1980's ultraviolet filters had been incorporated into intraocular lenses. This caused intense controversy, as there was concern that the UV-filtering chromophore might leach out into the eye causing toxicity. With the arrival of blue-filtering intraocular lenses (BFIOLs) in 1990's, a further debate was ignited as to their safety and potential disadvantages. Selecting the optimal performing intraocular lens to obtain the best visual performance with the fewest potential drawbacks has become complex and challenging for cataract surgeons and their patients with the wide choice of lenses available. Choosing a personalised lens to address astigmatism, presbyopia, spherical aberration, chromatic aberration, and potentially to shield the retina from short-wavelength light is now possible. The potential benefits and possible side effects of these different innovations emphasise the importance of assessing the evidence for their clinical utility, allowing the surgeon and the patient to weigh-up the risk benefit ratio and make an informed decision. The BFIOLs were developed to reduce cyanopsia, address chromatic aberration, and improve contrast sensitivity in different lighting conditions, as well as to prevent short-wavelength light reaching the retina thus potentially reducing the risk of developing age-related macular degeneration. Further design development of the BFIOLs was to mimic the natural crystalline lens absorption and transmittance properties in adulthood. Multiple publications have reported on the potential benefits and pitfalls of implanting a blue-filtering lens. The potential disadvantages raised in the literature over the last 25 years since their introduction, regarding compromise of visual function and disruption of the circadian system, have been largely dispelled. The clear benefits of protecting the retina from short-wavelength light make a BFIOLs a sensible choice. The purpose of this article presented at the Cambridge symposium 2015 is to review the literature on this subject.