Abstract:The great variability existing in the spectral transmission of the human crystalline lens is lesser between the ages of 40 and 59 years, but greater from the age of 60 and older. The decrement in transmittance between these two age groups varies from 40% for 420 nm to 18% for 580 nm. Nevertheless, it is proven that age is not the only parameter affecting crystalline transmission. In the range of 40 to 59 years, age does not bear an influence on total transmission of light, but from 60 years and older it does. … Show more
“…In this study, pupillary constriction responses to blue light were not selectively reduced in aging or in the presence of cataract, even though it is well established that more blue light is absorbed by the lens in older individuals613141516. Our findings are consistent with a recent study in which the magnitude of sustained pupillary constriction responses to blue light and green light stimuli (480 nm and 550 nm; 12.8, 13.5, or 14.0 log photons cm −2 s −1 ) did not differ between young and older subjects (18–30 years versus ≥55 years)17.…”
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.
“…In this study, pupillary constriction responses to blue light were not selectively reduced in aging or in the presence of cataract, even though it is well established that more blue light is absorbed by the lens in older individuals613141516. Our findings are consistent with a recent study in which the magnitude of sustained pupillary constriction responses to blue light and green light stimuli (480 nm and 550 nm; 12.8, 13.5, or 14.0 log photons cm −2 s −1 ) did not differ between young and older subjects (18–30 years versus ≥55 years)17.…”
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.
“…4 In terms of the IOL color, a clear lens has greater light transmittance than a yellow-colored IOL and thus the effect on circadian rhythm synchronization may be stronger. [43][44][45] Sleep quality is affected by many physiological and mental factors, as is photo-entrainment calculated from the IOL spectral transmission.…”
Background: Previously, we reported improvements in sleep quality and gait speed after implantation of a yellow-colored, blue light-blocking intra-ocular lens (IOL). This study evaluated systemic health parameters for 7 months after cataract surgery with implantation of a clear, ultraviolet (UV)-blocking IOL. Methods: A total of consecutive 71 patients (average age 74.1 years) underwent cataract surgery with the implantation of a clear, UV-blocking IOL. Participants were evaluated using the Pittsburgh Sleep Quality Index (PSQI) and the National Eye Institute Visual Function Questionnaire (VFQ-25) before and at 2 and 7 months after surgery. Four-meter gait speed was also determined. The metabolic parameters of serum glycated hemoglobin (HbA1c), triglycerides (TGs), low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol (HDL-C) were tested. Results: The pre-operative and post-operative (2 and 7 months after surgery) results were 66.4 -16.5, 79.5 -12.6, and 81.0 -13.0 for VFQ-25 score, 5.7 -3.5, 5.1 -3.1, and 4.8 -2.9 for PSQI, and 0.90 -0.22, 0.91 -0.22, and 0.92 -0.22 meters/sec for gait speed. Significant improvements following surgery were noted in the VFQ-25 score for all cases and in the PSQI for poor sleepers (preoperative PSQI > 5.5) (P < 0.05, paired t-test). The gait speed and metabolic parameters showed no significant changes. Conclusions: Cataract surgery with implantation of an UV-blocking clear IOL has the potential for improving circadian rhythm and systemic health parameters.
“…With increasing age and in the presence of systemic or ocular disease, media transmission is invariably altered (Wuerger 2013, Sakanishi et al 2012, Artigas et al 2012, Bron et al, 2000, Polo et al, 1996. This change in ocular media transparency and scattering effect (light diffusion) produced by a cataract can affect both spectral transmission and morphology.…”
To assess the impact of light scatter, similar to that introduced by cataract on retinal vessel blood oxygen saturation measurements using poly-bead solutions of varying concentrations.Eight healthy, young, non-smoking individuals were enrolled for this study. All subjects underwent digital blood pressure measurements, assessment of non-contact intraocular pressure, pupil dilation and retinal vessel oximetry using dual wavelength photography (Oxymetry Modul, Imedos Systems, Germany). To simulate light scatter, cells comprising a plastic collar and two plano lenses were filled with solutions of differing concentrations (0.001, 0.002 and 0.004%) of polystyrene microspheres (Polysciences Inc., USA). The adopted light scatter model showed an artifactual increase in venous optical density ratio (p=0.036), with the 0.004% condition producing significantly higher venous optical density ratio values when compared to images without a cell in place. Spectrophotometric analysis, and thus retinal vessel oximetry of the retinal vessels, is altered by artificial light scatter.
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