Blue Filtering Intraocular Lenses Research Articles

Evaluation of Visual Comfort and Mental Effort Under Different Light Conditions for Ultraviolet-Absorbing and Additional Blue-Filtering Intraocular Lenses for Cataract Surgery

Patients with an ultraviolet blocking lens (UV) (n = 5) or blue filter lens (BB) (n = 8) after intraocular lens (IOL) replacement for cataract and age-adjusted controls (AACs) (n = 16) underwent a balanced crossover within-subject design. After 1.5 h of dark adaptation, they were exposed to polychromatic light at 6500 K (blue-enriched) and 2500 K and 3000 K (non-blue-enriched) for 2 hours in the evening. Visual comfort and mental effort were repeatedly assessed by the Visual Analogue Scale (0 - 100) and the Visual Comfort and Mental Effort Rating Scale (0 - 100) for each light condition. The results were compared using mixed model analysis. The mean (± SD) age for AAC and patients with UV or BB was 69.8 ± 6.2 y, 70.8 ± 4 y, and 63.6 ± 5.6 y, respectively. Irrespective of the light condition, patients with UV and BB felt mentally more tired during the experiments compared to AACs (F = 6.15, p = 0.003). However, patients with BB were mentally more motivated to perform the exercises compared to patients with UV and AACs (F = 8.1, p < 0.001). Patients with BB perceived ambient light as less glary (F = 4.71, p = 0.01) than patients with UV. Blue ambient light was felt less intensely in patients with BB (F = 2.51, p = 0.042) compared to those with UV and the AACs. Lens replacement in older cataract patients may increase visual comfort and minimize mental effort. While subtle, the magnitude of these effects may depend on the type of intraocular lens. BB intraocular lenses may have potential benefits, as ambient light is perceived as having less glare and less visual tension.

The effect of cataract surgery on sleep quality: a systematic review and Meta-analysis.

To evaluate the effect of cataract surgery on sleep quality and to compare the difference between ultraviolet-blocking clear intraocular lens (UVB-IOL) and blue-filtering intraocular lens (BF-IOL) implantation. Electronic search was performed of PubMed, MEDLINE, Embase and the Cochrane Library up to January 2016. Studies were eligible when they evaluated the sleep quality before and after cataract surgery by Pittsburgh sleep quality index (PSQI). A random/fixed-effects Meta-analysis was used for the pooled estimate. Heterogeneity was assessed with the I2 test. Six studies were selected from 5623 references. Cataract surgery significantly reduced the PSQI scores at postoperative 0-3mo [mean difference (MD) =-0.62, 95%CI: -1.14 to -0.11, P=0.02, I2=66%] and 3-12mo (MD=-0.32, 95%CI: -0.62 to -0.02, P=0.04, I2=0), respectively. Considering different intraocular lens (IOL) implantations, relative post-operative PSQI reduction was found for both UVB-IOL and BF-IOL, but a significant reduction was detected only for UVB-IOL. No significant difference was found with the effect of BF-IOL vs UVB-IOL on sleep quality. This study found that cataract surgery significantly improved the PSQI score-derived subjective sleep quality irrespective of the IOL type implanted. These findings highlight a substantial benefit of cataract surgery on systemic health with photoreceptive restoration in addition to visual acuity improvements.

백내장 수술 후 수면 변화에 관한 통합적 고찰

Purpose: The purpose of this study was to review previous literature with an aim to explore the sleep disturbance level after a patient undergoes cataract surgery using an integrative review. Methods: We used the key words, ‘cataract surgery’, ‘sleep’, and ‘intraocular lens’ to find peer-reviewed publications in seven databases. Among 450 searched articles, eight articles were selected after exclusion of articles that did not meet the criteria. Results: Five of the articles submitted that subjective sleep quality of the patients with blue-filtering intraocular lens (BF-IOL) implant improved as compared to that before surgery. The change of saliva melatonin concentration after BF-IOL implant did not coincide in two of the articles. Two of the articles reported an increased level of intrinsically photosensitive retinal ganglion cells response after BF-IOL implantation. Conclusion: The published studies stated that BF-IOL implant did not have any negative impact on quality of sleep among cataract patients suffering with poor sleep. Rregardless of intraocular lens type, cataract surgery may increase photoreception of intrinsically photosensitive retinal ganglion cells one year after surgery although the mechanism was not clear. It is necessary to identify various factors influencing the quality of sleep such as gender and activities among cataract patients with BF-IOL implant in the future. Key Words: Cataract; Lenses; Intraocular; Review; Sleep Key Words: 백내장; ì¸ê³µìˆ˜ì •ì²´; ì¢ ì„¤; 수면

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.

Spektrale Durchlässigkeit bei Blaufilter-Intraokularlinsen

There is uncertainty in ophthalmology concerning the quality and spectral transmission of light of so-called blue filter intraocular lenses (IOL). Clinical users have noticed that such IOL's appear to have different color intensities. The discussion on medical changes by means of such IOL's is dependent on the real light transmission of these IOL's. To add some objective data we compared these IOL's by systematic transmission measurements and observed technical differences of diffraction and geometry as well as transmission differences. The result gives objective indications that differences between blue filter IOL's from different manufacturers are important and are detailed in this paper.

Preferring Blue Light-filtering Lenses

The spectral permeability of intraocular lenses (IOL) determines the known “blue hazard” for the retina, which affects the development of age related macular degeneration (AMD). On the one hand, the blue hazard causes irreversible damage to the blue receptors. Further, the yellow lipofuscins that are deposited during the daily partial replacement of the outer segments of the photoreceptors on the retina tend to fluoresce in the blue light. This light energy activates the oxygen that is present, resulting in the formation of highly active, toxic radicals (reactive oxygen species, ROS). These can be warded off only to a degree. The eye protects itself against UV damage because the lens absorbs UV light and may thus develop a cataract. The age related yellowing of the lens is akin to an increase in the blue protection and makes sense physiologically because with increasing age the risk of retinal damage increases owing to the imbalance of ROS lipofuscins and repair mechanisms. The blue hazard that is caused by a colorless intraocular lens is clearly in excess of that of a 4 year old child (!) and, because it happens to a retina that is already weakened, it increases the risk of AMD. For the violet and blue spectrum, the blue-filtering intraocular lens imitates the permeability curve of the lens of a 50 year old. Although several questions remain unanswered (1), the blue-filtering lens should be preferred and colorless lenses used only for particular indications. Further, the permeability curve of sunglasses is crucial for the risk associated with light and the progression of AMD (2, 3).

Sharp cutoff filters in intraocular lenses optimize the balance between light reception and light protection

To facilitate the selection of the spectral filter in intraocular lenses (IOLs). Department of Ophthalmology, University Medical Center Utrecht, Utrecht, The Netherlands. The spectral transmission of commercially available IOLs was measured, and information from manufacturer data sheets and the literature was gathered. Illumination with sunlight filtered by the natural eye media (aged 20 and 70 years) and artificial eye media resulted in calculated values for the blue-light damage and the signals from the sensory systems (rods, cones, melatonin suppression, and melanopsin). Results were presented as log differences with respect to the 20-year-old human lens. A single rating value for each lens was calculated to facilitate the selection. The 70-year-old lens showed a reduction in blue-light damage of 0.45 log units compared to the 20-year-old lens, although a similar reduction occurred in the signal from the short-wave-sensitive cones. Intraocular lenses showed a range of nearly 1 log unit in blue-light damage protection. A change in dioptric power in blue-filtering IOLs, with a corresponding change in thickness, strongly influenced behavior. Dioptric power was less of a factor in IOLs with sharp cutoff filters. Blue-filtering IOLs sometimes showed density spectra very different from those of the natural lens; however, their filtering generally caused only mild sensory losses. Nearly none of the IOLs offered an optimum tradeoff between protection and signal reduction. Sharp cutoff filtering near 445 nm provided better performance, removing limitations in optical design.

Visuelle Funktion mit Blaulichtfilter-IOL

Recently, intraocular lenses (IOLs) with a blue light filter have been introduced to protect the retina from age-related macular degeneration (AMD) after cataract extraction. A reduction of longitudinal chromatic aberration by filtering blue light may enhance patient's visual function. In this study we compared subjective and objective parameters of visual function following implantation of blue light filter (yellow) IOLs and IOLs of the same design without filter. 21 patients (21 eyes) underwent implantation of an IOL with a blue light filter (AF-1 UY, Hoya, Japan), 22 patients (22 eyes) received an IOL without blue light filter (AF-1 UV, Hoya, Japan). Patients were examined three months postoperatively for uncorrected and best corrected spectacle visual acuity, mesopic and photopic contrast sensitivity, colour vision and subjective quality of vision by a standard questionnaire. Eyes with blue light filter IOLs did not show any significant difference in any parameter analysed when compared to eyes without the blue light filter IOL. Subjective quality of vision was considered to be high by all patients and no significant difference was observed between the two IOL groups. The visual function of patients with blue filter IOLs is not significantly different to those without blue light filter IOLs. Since blue light filter IOLs did not show any functional disadvantage, but potentially protect the macula from AMD, blue light filter IOLs may be considered as a reasonable alternative to traditional IOLs, especially in eyes with a high risk for the development of macular degeneration.