REVIEW URRENT C OPINION
Ultraviolet-blocking intraocular lenses: fact or fiction Edward Lai, Benjamin Levine, and Jessica Ciralsky
Purpose of review Ultraviolet-blocking intraocular lenses (IOLs) are used routinely in cataract surgery and are widely accepted. Blue-blocking IOLs, however, have been much debated since their inception. In this article, we will review the advantages and disadvantages of blue-blocking IOLs. Recent findings In experimental and animal studies, acute blue light exposure induces retinal damage and the use of blue-blocking IOLs lessens this damage. Many large epidemiologic studies have further investigated this relationship between blue light exposure and the development of age-related macular degeneration, and have shown conflicting results. Visual performance and circadian rhythm disturbances have also been explored in patients with blue-blocking IOLs; no significant negative effects have been shown. Summary The current literature on blue-blocking IOLs is contradictory. Studies have failed to conclusively prove that blue-blocking lenses provide photoprotection against age-related macular degeneration or cause any significant detrimental effects on visual function or circadian rhythms. Keywords age-related macular degeneration, blue-blocking intraocular lens, circadian rhythm, scotopic sensitivity, ultraviolet-blocking intraocular lens
INTRODUCTION The human eye is naturally designed to block harmful ultraviolet (UV) light. The retina’s first line of defense against phototoxic damage is the cornea and crystalline lens. The cornea blocks UV wavelengths below 300 nm, and the natural crystalline lens blocks UV wavelengths in the 300–400 nm range [1–5]. With age, the crystalline lens yellows, resulting in increased absorption of UV light, particularly in the blue portion of the spectrum [1–4,6–8]. When the natural crystalline lens is removed during cataract surgery, its protective effects are lost and the retina’s exposure to harmful blue light is increased. Intraocular lens (IOL) design has been modified over the years to try to simulate these protective properties of the natural crystalline lens. The earliest IOL implants allowed unrestricted UV and visible light to penetrate the eye [5,9]. In the mid-1980s, prompted by the concern that UV light could damage the retina, IOL implants began to incorporate UV radiation blocking chromophores [5,10]. Particular concern over the possible retinal toxicity from short wavelengths of visible light [11] led to the development
and adoption of the blue-blocking IOLs in the 1990s. There has been wide acceptance and little controversy surrounding the use of UV-blocking IOLs, especially as UV radiation is unnecessary for vision. Blue-blocking IOLs, on the other hand, have been much debated since their inception. There is no question that blue-blocking IOLs decrease the exposure of the retina to wavelengths of light in the blue spectrum; however, the increased photoprotective effect of these lenses remains in question. Advocates for the use of blue-blocking lenses cite its theoretical ability to decrease the risk of agerelated macular degeneration without compromising the visual acuity, color vision, scotopic vision, or contrast sensitivity [12–15]. Adversaries claim that blue-blocking lenses cause poorer scotopic vision Weill Cornell Medical College, New York, New York, USA Correspondence to Jessica Ciralsky, MD, Weill Cornell Medical College, 1305 York Avenue, 11th Floor, New York, NY 10021, USA. Tel: +1 646 962 2020; fax: +1 646 962 0603; e-mail: [email protected] Curr Opin Ophthalmol 2014, 25:35–39 DOI:10.1097/ICU.0000000000000016
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KEY POINTS The phototoxicity–age-related macular degeneration hypothesis is based on experimental and animal studies; large epidemiological studies have failed to conclusively prove this association. Most studies conducted have reported no significant changes in terms of color vision or contrast sensitivity with blue-blocking lenses; the only two studies to the contrary had nonsignificant findings. Given the great improvement in light transmission achieved simply by removing the cataract, it seems unlikely that blue-blocking intraocular lenses cause any significant disruptions to the circadian rhythm.
and disruption of circadian rhythms without providing any proven photoprotection against agerelated macular degeneration [16–19]. Many studies have been published in response to the blue-blocking debate; yet, there still seems to be a lack of consensus for or against their use among eye care professionals. In this article, we will review the major controversies associated with blue-blocking IOLs.
ULTRAVIOLET LIGHT PHOTOTOXICITY AND BLUE-BLOCKING INTRAOCULAR LENS RETINAL PHOTOPROTECTION Age-related macular degeneration affects 11.5% of the population in the USA and is one of the leading causes of blindness in the developed world [20,21]. With the aging general population, the incidence of age-related macular degeneration will increase considerably, likely doubling in the next 20 years [20,21]. This growing burden on patients and society has prompted the search for better treatments and prevention measures. Several experimental and animal studies have shown the danger of light exposure, particularly in the short wavelength spectrum, on the retina [11,22–26]. The biological basis of these experiments is thought to be blue-light-induced apoptosis of the retinal pigment epithelium, mediated by the lipofuscin fluorophore A2E [27,28]. These studies provide convincing evidence that blue light exposure can damage the retina in experimental and animal models; the implication for retinal damage in humans from long-term, low-intensity light exposure, however, is unclear. Many epidemiologic studies, both populationbased and case–control studies, have examined the association between exposure to environmental 36
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light and the development or progression of agerelated macular degeneration. A positive association between light exposure and age-related macular degeneration has been shown in quite a few studies [29–35], including a study by Taylor et al. [31], who found that patients with advanced age-related macular degeneration had a 48% higher exposure to blue light during the previous 20 years than controls. One additional study by Fletcher et al. [35] only showed an increased risk of age-related macular degeneration in the subset of patients with low antioxidant levels. A number of other large studies failed to find an association between light exposure and age-related macular degeneration [36–43]. The existing evidence is difficult to interpret, given the widely variable and conflicting data. Part of the problem stems from the fact that it is very challenging to determine a patient’s cumulative light exposure retrospectively. Additionally, agerelated macular degeneration is a multifactorial disease involving many variables including genetics, smoking, diet, and geographic location, making the analysis of one association more difficult [29]. Age-related macular degeneration development and progression has also been linked to cataract surgery. This linkage is based on the hypothesis that removal of the cataractous crystalline lens, which blocked a significant amount of blue light, allows more harmful blue light to reach the retina. A recent study by Klein et al. [44 ] evaluated the association between cataract, cataract surgery, and age-related macular degeneration over a 20-year interval. They did not find an association among cataract or cataract surgery and the development of early agerelated macular degeneration. They did, however, find that there was a positive association between cataract surgery and the incidence of late age-related macular degeneration, even after controlling for other risk factors. Several other studies have also supported a positive association reporting up to a 5.7-fold increase in the incidence of late-stage, agerelated macular degeneration in nonphakic vs. phakic individuals [44 ,45–54]. Conversely, many other studies have failed to find supporting evidence linking age-related macular degeneration to cataract surgery [40,55–59]. Furthermore, several studies have even shown a relationship between cataracts and age-related macular degeneration [46,47,54], making the previous results difficult to interpret. The possibility that blue-light exposure can increase the risk of age-related macular degeneration led to the development of blue-blocking, yellow tinted IOLs. Many studies have examined the transmittance spectrum of different available IOLs [9,60,61,62 ]. A recent report by Tanito et al. [62 ] showed that yellow tinted IOLs absorb more &&
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Ultraviolet-blocking intraocular lenses Lai et al.
blue light than clear IOLs and aphakic eyes. They showed that yellow tinted IOLs reduced blue-light irradiance by 62–82%, whereas clear UV-blocking lenses only provided reductions of 43–64%. To further explore this subject, several studies tested the ability of yellow filters to lessen the induced retinal damage previously shown in the experimental models [63–67]. Sparrow et al. [63] exposed cultured human retinal pigment epithelial cells to blue light in the presence or absence of an IOL. They showed a protective effect of blue-blocking lenses against retinal pigment epithelial cell death. The phototoxicity–age-related macular degeneration hypothesis is still very controversial. Experimental models show obvious retinal damage from high-intensity blue-light exposure and reduced retinal damage with the introduction of blue-blocking IOLs. The extrapolation of these findings to reallife scenarios, however, is unclear. Furthermore, large epidemiologic studies have reported contradictory findings. Several studies have shown a positive association between sunlight and age-related macular degeneration, and many other large studies have failed to find any correlation. Thus, the necessity of blue-blocking IOLs to decrease the risk of agerelated macular degeneration remains controversial and based mainly on theoretical protective properties.
SCOTOPIC SENSITIVITY AND VISUAL FUNCTION Scotopic sensitivity and night vision decline with age as the number of rod photoreceptors naturally decrease each year [68]. As night vision peaks at approximately 500 nm, IOLs that filter out blue light can theoretically reduce scotopic sensitivity and decrease dark adaptation [69,70]. A significant decrease in scotopic sensitivity and dark adaptation can be detrimental in an elderly population, and has been correlated with a risk of falling [71]. Many researchers have compared scotopic sensitivity with blue-blocking and UV-blocking lenses. A few studies have found a decrease in scotopic sensitivity, by approximately 14–21%, when a blue-blocking lens was used [5,69,70,72]. Two additional studies also showed decreased scotopic sensitivity with the use of blue-blocking IOLs; however, they reported that the clinical effects were negligible [73,74]. Several other studies failed to find any decreased scotopic sensitivity with the use of blue-blocking lenses [75,76]. If scotopic sensitivity is indeed reduced, the clinical significance is likely minimal. Concern over the loss of contrast sensitivity and color vision with blue-blocking IOLs has also been raised. Many studies have explored this subject
in detail, and most have shown comparable results with blue-blocking and UV-blocking IOLs in terms of color vision and contrast sensitivity [75–85]. A few studies have even showed improved contrast sensitivity with blue-blocking IOLs [86,87]. Schmidinger et al. [88] showed that although there were no significant differences in color vision, two patients reported minor subjective color changes, although neither patient required explantation of the IOL. Another study by Wirtitsch et al. [89] found that patients with blue-blocking IOLs had worse contrast acuity compared with patients with UVblocking IOLs; the differences, though, were small and of unclear significance. The majority of the studies conducted have reported no significant changes in terms of color vision or contrast sensitivity with blue-blocking lenses. Only two studies to the contrary had nonsignificant findings.
CIRCADIAN CYCLE Behavioral adjustment to ambient light is a fundamental aspect of life. In 2002, blue-light-sensitive nonvisual ganglion cells in the retina were discovered. They contain melanopsin, a photopigment with maximal sensitivity in the blue portion of the spectrum. These ganglion cells respond directly to blue light stimulation and are thought to play a critical role in maintaining effective circadian photoentrainment [90]. They help control the biological clock through suppression of melatonin secretion [90]. In darkness, the pineal gland secretes melatonin and causes sleepiness; in bright light, melatonin is suppressed leading to increased alertness. Previous reports have shown that the prevalence of circadian disorders increases with age [91]. Part of this phenomenon may be due to the fact that there is a decreased amount of light reaching the visual system as we age, secondary to pupillary miosis and yellowing of the human crystalline lens. Cataract surgery improves the overall light transmission to the retina and has been shown to improve a patient’s sleep pattern. Concerns about the possible negative effects on the circadian rhythms with the use of blue-blocking lenses have been expressed. Mainster [5] showed that blue-blocking lenses decrease melatonin suppression by 27–38% compared with UV-blocking lenses. A study by Landers et al. [92], however, showed that the use of blueblocking IOLs had no detrimental effects on the quality of sleep. A recent study by Brondsted et al. [93 ] explored the effects of aging crystalline lenses and several different IOLs on the photoentrainment of the circadian rhythm. They showed that all of the IOLs (UV, violet-blocking, and blue-blocking) had a
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minimal effect on melanopsin activation, whereas older human lenses had a significant effect. Given the great improvement in light transmission simply by removing the cataract, it seems unlikely that blue-blocking IOLs cause any significant disruption to the circadian rhythm.
CONCLUSION The ideal IOLs should have a photoprotective effect against all harmful wavelengths of light, while maintaining optimal visual performance in photopic as well as scotopic environments. Review of the current literature shows that the relationship of blue light exposure to the development and progression of agerelated macular degeneration remains inconclusive, as does the association between cataract surgery and age-related macular degeneration. In addition, the majority of the literature states that there are no detrimental effects of blue-blocking IOLs on scotopic visual function or circadian rhythms, although there are a few studies to the contrary. There has been limited new information published on this topic in the last year. In order to definitively answer the questions surrounding the possible benefits and detriments of blue-blocking IOLs, prospective, randomized trials are necessary. It is the responsibility of every cataract surgeon to be familiar with the wide variety of available IOLs and to select the implant best suited for each individual patient. Acknowledgements None. Conflicts of interest The work of E.L., B.L., and J.C. is supported by a grant from Research to Prevent Blindness. There are no conflicts of interest.
REFERENCES AND RECOMMENDED READING Papers of particular interest, published within the annual period of review, have been highlighted as: & of special interest && of outstanding interest 1. Cuthbertson FM, Peirson SN, Wulff K, et al. Blue light-filtering intraocular lenses: review of potential benefits and side effects. J Cataract Refract Surg 2009; 35:1281–1297. 2. Boettner EA, Wolter JR. Transmission of the ocular media. Invest Ophthalmol 1962; 1:776–783. 3. Norren DV, Vos JJ. Spectral transmission of the human ocular media. Vision Res 1974; 14:1237–1244. 4. Mellerio J. Yellowing of the human lens: nuclear and cortical contributions. Vision Res 1987; 27:1581–1587. 5. Mainster MA. Violet and blue light blocking intraocular lenses: photoprotection versus photoreception. Br J Ophthalmol 2006; 90:784–792. 6. Mainster MA. Intraocular lenses should block UV radiation and violet but not blue light. Arch Ophthalmol 2005; 123:550–555. 7. Bron AJ, Vrensen GF, Koretz J, et al. The ageing lens. Ophthalmologica 2000; 214:86–104.
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8. Weale RA. Age and the transmittance of the human crystalline lens. J Physiol 1988; 395:577–587. 9. Mainster MA. Spectral transmittance of intraocular lenses and retinal damage from intense light sources. Am J Ophthalmol 1978; 85:167–170. 10. Mainster MA. The spectra, classification, and rationale of ultraviolet-protective intraocular lenses. Am J Ophthalmol 1986; 102:727–732. 11. Ham WT, Mueller HA, Sliney DH. Retinal sensitivity to damage from short wavelength light. Nature 1976; 260:153–155. 12. Symes RJ, Cuthbertson FM. Blue-blocking intraocular implants should be used routinely during phacoemulsification surgery – yes. Eye 2012; 26:1397–1399. 13. Henderson BA, Grimes KJ. Blue-blocking IOLs: a complete review of the literature. Surv Ophthalmol 2010; 55:284–289. 14. Braunstein RE, Sparrow JR. A blue-blocking intraocular lens should be used in cataract surgery. Arch Ophthalmol 2005; 123:547–549. 15. Lee RMH, Cuthbertson FM, Soderberg P, Liu CS. A possible strategy for implanting blue-blocking intraocular lenses. Acta Ophthalmol 2012; 90:e151. 16. Lee RMH, Lam FC, Liu CSC. Blue-blocking intraocular implants should be used routinely during phacoemulsification surgery – no. Eye 2012; 26: 1400–1401. 17. Mainster MA, Turner PT. Blue-blocking intraocular lenses: myth or reality? Am J Ophthalmol 2009; 147:8–10. 18. Mainster MA, Turner PL. Blue-blocking IOLs vs. short-wavelength visible light: hypothesis-based vs evidence-based medical practice. Ophthalmology 2011; 118:1–2. 19. Mainster MA, Turner PL. Blue-blocking IOLs decrease photoreception without providing significant photoprotection. Surv Ophthalmol 2010; 55:272– 283. 20. Friedman DS, O’Colmain BJ, Munoz B, et al., Eye Disease Prevalence Research Group. Prevalence of age-related macular degeneration in the United States. Arch Ophthalmol 2004; 122:564–572. 21. Wong IYH, Koo SCY, Chan CWN. Prevention of age-related macular degeneration. Int Ophthalmol 2011; 31:73–82. 22. Gorgels GMF, Van Norren D. Ultraviolet and green light cause different types of damage in rat retina. Invest Ophthalmol Vis Sci 1995; 36:851–863. 23. Noell WK, Walker VS, Kang BS, et al. Retinal damage by light in rats. Invest Ophthalmol 1966; 5:450–473. 24. Van Norren D, Schellekens P. Blue light hazard in rat. Vision Res 1990; 30:1517–1520. 25. Grimm C, Wenzel A, Williams TP, et al. Rhodopsin-mediated blue-light damage to the rat retina: effect of photoreversal of bleaching. Invest Ophthalmol Vis Sci 2001; 42:497–505. 26. Ham WT Jr, Ruffolo JJ Jr, Mueller HA, et al. Histologic analysis of photochemical lesions produced in rhesus retina by short wave-length light. Invest Ophthalmol Vis Sci 1978; 1:1029–1035. 27. Sparrow JR, Nakanishi K, Parish CA. The lipofuscin fluorophore A2E mediates blue light-induced damage to retinal pigment epithelial cells. Invest Ophthalmol Vis Sci 2000; 41:1981–1989. 28. Hunter JJ, Morgan JIW, Merigan WH, et al. The susceptibility of the retina to photochemical damage from visible light. Prog Retin Eye Res 2012; 31:28– 42. 29. Tomany SC, Cruickshanks KJ, Klein R, et al. Sunlight and the 10-year incidence of age-related maculopathy: the Beaver Dam Eye Study. Arch Ophthalmol 2004; 122:750–757. 30. Taylor HR, Munoz B, West S, et al. Visible light and risk of age-related macular degeneration. Trans Am Ophthalmol Soc 1990; 88:163–173. 31. Taylor H, West S, Munoz B, et al. The long-term effects of visible light on the eye. Arch Ophthalmol 1992; 110:99–104. 32. Cruickshanks KJ, Klein R, Klein BE. Sunlight and age-related macular degeneration. The Beaver Dam Eye Study. Arch Ophthalmol 1993; 111: 514–518. 33. Cruickshanks KJ, Klein R, Klein BE, Nondahl DM. Sunlight and the 5-year incidence of early age-related maculopathy: the Beaver Dam Eye Study. Arch Ophthalmol 2001; 119:246–250. 34. Hirakawa M, Tanaka M, Tanaka Y, et al. Age-related maculopathy and sunlight exposure evaluated by objective measurement. Br J Ophthalmol 2008; 92:630–634. 35. Fletcher AE, Bentham GC, Agnew M, et al. Sunlight exposure, antioxidants, and age-related macular degeneration. Arch Ophthalmol 2008; 126:1396– 1403. 36. Darzins P, Mitchell P, Heller RF. Sun exposure and age-related macular degeneration: an Australian case–control study. Ophthalmology 1997; 104:770–776. 37. McCarty CA, Mukesh BN, Fu CL, et al. Risk factors for age-related maculopathy: the Visual Impairment Project. Arch Ophthalmol 2001; 119:1455– 1462. 38. Delcourt C, Carriere I, Ponton-Sanchez A, et al. Light exposure and the risk of age-related macular degeneration: the Pathologies Oculaires Liees a I’Age (POLA) study. Arch Ophthalmol 2001; 119:1463–1468. 39. Hirvela H, Luukinen H, Laara E, et al. Risk factors of age-related maculopathy in a population 70 years of age or older. Ophthalmology 1996; 103:871– 877. 40. Clemons TE, Milton RC, Klein R, et al. Risk factors of the incidence of advanced age-related macular degeneration in the Age-Related Eye Disease Study (AREDS). AREDS report no. 19. Ophthalmology 2005; 112:533–539.
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Ultraviolet-blocking intraocular lenses Lai et al. 41. Risk factors for neovascular age-related macular degeneration. The Eye Disease Case–Control Study Group. Arch Ophthalmol 1992; 110:1701–1708. 42. Khan JC, Shahid H, Thurlby DA, et al. Age related macular degeneration and sun exposure, iris colour, and skin sensitivity to sunlight. Br J Ophthalmol 2006; 90:29–32. 43. West SK, Rosenthal FS, Bressler NM, et al. Exposure to sunlight and other risk factors for age-related macular degeneration. Arch Ophthalmol 1989; 107:875–879. 44. Klein BE, Howard KP, Lee KE, et al. The relationship of cataract and cataract && extraction to age-related macular degeneration: the Beaver Dam Eye Study. Ophthalmology 2012; 119:1628–1633. This article evaluated the associations among cataract, cataract surgery, and agerelated macular degeneration over a 20-year interval. They found a positive association between cataract surgery and the incidence of late age-related macular degeneration, even after controlling for other risk factors. 45. Pollack A, Marcovich A, Bukelman A, Oliver M. Age-related macular degeneration after extracapsular cataract extraction with intraocular lens implantation. Ophthalmology 1996; 103:1546–1554. 46. Chaine G, Hullo A, Sahel J, et al. Case–control study of the risk factors for age related macular degeneration France-DMLA Study Group. Br J Ophthalmol 1998; 82:996–1002. 47. Klein R, Klein BE, Wong TY, et al. The association of cataract and cataract surgery with the long-term incidence of age-related maculopathy: the Beaver Dam Eye Study. Arch Ophthalmol 2002; 120:1551–1558. 48. Wang JJ, Klein R, Smith W, et al. Cataract surgery and the 5-year incidence of late-stage age-related maculopathy: pooled findings from the Beaver Dam and Blue Mountain Eye studies. Ophthalmology 2003; 110:1960–1967. 49. Klein R, Klein BE, Jensen SC, Cruickshanks KJ. The relationship of ocular factors to the incidence and progression of age-related maculopathy. Arch Ophthalmol 1998; 116:506–513. 50. Cugati S, Mitchell P, Rochtchina E, et al. Cataract surgery and the 10-year incidence of age-related maculopathy: the Blue Mountains Eye Study. Ophthalmology 2006; 113:2020–2025. 51. Chakravarthy U, Wong TY, Fletcher A, et al. Clinical risk factors for age-related macular degeneration: a systematic review and meta-analysis. BMC Ophthalmol 2010; 10:31. 52. Ho L, Boekhoorn SS, Liana van Duijn CM, et al. Cataract surgery and the risk of aging macula disorder: the Rotterdam study. Invest Ophthalmol Vis Sci 2008; 49:4795–4800. 53. Bockelbrink A, Roll S, Ruether K, et al. Cataract surgery and the development or progression of age-related macular degeneration: a systematic review. Surv Ophthalmol 2008; 53:359–367. 54. Freeman EE, Munoz B, West SK, et al. Is there association between cataract surgery and age-related macular degeneration? Data from three population based studies. Am J Ophthalmol 2003; 135:849–856. 55. Armbrecht AM, Findlay C, Aspinall PA, et al. Cataract surgery in patients with age-related macular degeneration: one-year outcomes. J Cataract Refract Surg 2003; 29:686–693. 56. Sutter FK, Menghini M, Barthelmes D, et al. Is pseudophakia a risk factor for neovascular age-related macular degeneration? Invest Ophthalmol Vis Sci 2007; 48:1472–1475. 57. Xu L, Li Y, Zheng Y, Jonas JB. Associated factors for age related maculopathy in the adult population in China: the Beijing Eye Study. Br J Ophthalmol 2006; 90:1087–1090. 58. Baatz H, Darawsha R, Ackermann H, et al. Phacoemulsification does not induce neovascular age-related macular degeneration. Invest Ophthalmol Vis Sci 2008; 49:1079–1083. 59. Chew EY, Sperduto RD, Milton RC, et al. Risk of advanced age-related macular degeneration after cataract surgery in the Age-Related Eye Diseases Study: AREDS report 25. Ophthalmology 2009; 116:297–303. 60. Brockmann C, Schulz M, Laube T. Transmittance characteristics of ultraviolet and blue-light-filtering intraocular lenses. J Cataract Refract Surg 2008; 34:1161–1166. 61. Tanito M, Okuno T, Ishiba Y, Ohira A. Transmission spectrums and retinal blue-light irradiance values of untinted and yellow-tinted intraocular lenses. J Cataract Refract Surg 2010; 36:299–307. 62. Tanito M, Okuno T, Ishiba Y, Ohira A. Measurements of transmission spectrums & and estimation of retinal blue-light irradiance values of currently available clear and yellow-tinted intraocular lenses. Jpn J Ophthalmol 2012; 56:82–90. This article compared the most recent spectral transmission characteristics of available intraocular lenses. Yellow tinted intraocular lenses reduced blue-light irradiance by 62–82%, whereas clear ultraviolet-blocking lenses only provided reductions of 43–64%. 63. Sparrow JR, Miller AS, Zhou J. Blue light-absorbing intraocular lens and retinal pigment epithelium protection in vitro. J Cataract Refract Surg 2004; 30:873– 878. 64. Mukai K, Matsushima H, Sawano M, et al. Photoprotective effect of yellowtinted intraocular lenses. Jpn J Ophthalmol 2009; 53:47–51. 65. Yanagi Y, Inoue Y, Iriyama A, Jang WD. Effects of yellow intraocular lenses on light-induced upregulation of vascular endothelial growth factor. J Cataract Refract Surg 2006; 32:1540–1544.
66. Tanito M, Kaidzu S, Anderson RE. Protective effects of soft acrylic yellow filter against blue light-induced retinal damage in rats. Exp Eye Res 2006; 83:1493–1504. 67. Nilsson SE, Textorius O, Andersson BE, Swenson B. Clear PMMA versus yellow intraocular lens material. An electrophysiologic study on pigmented rabbits regarding ‘the blue light hazard’. Prog Clin Biol Res 1989; 314:539– 553. 68. Jackson GR, Owsley C, Curcio CA. Photoreceptor degeneration and dysfunction in aging and age-related maculopathy. Ageing Res Rev 2002; 1:381–396. 69. Mainster MA, Sparrow JR. How much blue light should an IOL transmit. Br J Ophthalmol 2003; 87:1523–1529. 70. Schwiegerling J. Blue-light-absorbing lenses and their effect on scotopic vision. J Cataract Refract Surg 2006; 32:141–144. 71. McMurdo ME, Gaskell A. Dark adaptation and falls in the elderly. Gerontology 1991; 37:221–224. 72. Pons A, Delgado D, Campos J. Determination of the action spectrum of the blue-light hazard for different intraocular lenses. J Opt Soc Am A Opt Image Sci Vis 2007; 24:1545–1550. 73. Werner JS. Night Vision in the elderly: consequences for seeing through a ‘blue filtering’ intraocular lens. Br J Ophthalmol 2005; 89:1518–1521. 74. Kiser AK, Deschler EK, Dagnelie G. Visual function and performance with blue-light blocking filters in age-related macular degeneration. Clin Exp Ophthalmol 2008; 36:514–520. 75. Greenstein VC, Chiosi F, Baker P, et al. Scotopic sensitivity and color vision with a blue-light-absorbing intraocular lens. J Cataract Refract Surg 2007; 33:667–672. 76. Muftuoglu O, Karel F, Duman R. Effect of a yellow intraocular lens on scotopic vision, glare disability and blue color perception. J Cataract Refract Surg 2007; 33:658–666. 77. Hayashi K, Hayashi H. Visual function in patients with yellow tinted intraocular lenses compared with vision in patients with nontinted intraocular lenses. Br J Ophthalmol 2006; 90:1019–1023. 78. Landers J, Tan TH, Yuen J, Liu H. Comparison of visual function following implantation of AcrySof natural intraocular lenses with conventional intraocular lenses. Clin Exp Ophthalmol 2007; 35:152–159. 79. Rodriguez-Galietero A, Montes-Mico R, Munoz G, Albarran-Diego C. Comparison of contrast sensitivity and color discrimination after clear and yellow intraocular lens implantation. J Cataract Refract Surg 2005; 31:1736– 1740. 80. Marshall J, Cionni RJ, Davison J, et al. Clinical results of the blue-light filtering AcrySof Natural foldable acrylic intraocular lens. J Cataract Refract Surg 2005; 31:2319–2323. 81. Raj SM, Vasavada AR, Nanavaty MA. AcrySof Natural SN60AT versus AcrySof SA60AT intraocular lens in patients with color vision defects. J Cataract Refract Surg 2005; 31:2324–2328. 82. Cionni RJ, Tsai JH. Color perception with AcrySof natural and AcrySof singlepiece intraocular lenses under photopic and mesopic conditions. J Cataract Refract Surg 2006; 32:236–242. 83. Bhattacharjee H, Bhattacharjee K, Medhi J. Visual performance: comparison of foldable intraocular lenses. J Cataract Refract Surg 2006; 32:451–455. 84. Vuori ML, Mantyjarvi M. Colour vision and retinal nerve fibre layer photography in patients with an AcrySof natural intraocular lens. Acta Ophthalmol Scand 2006; 84:92–94. 85. Leibovitch I, Lai T, Porter N, et al. Visual outcomes with the yellow intraocular lens. Acta Ophthalmol Scand 2006; 84:95–99. 86. Yuan Z, Reinach P, Yuan J. Contrast sensitivity and color vision with a yellow intraocular lens. Am J Ophthalmol 2004; 138:138–140. 87. Niwa K, Yoshino Y, Okuyama F, Tokoro T. Effects of tinted intraocular lens on contrast sensitivity. Ophthalmic Physiol Opt 1996; 16:297–302. 88. Schmidinger G, Menapace R, Pieh S. Intraindividual comparison of color contrast sensitivity in patient with clear and blue-light-filtering intraocular lenses. J Cataract Refract Surg 2008; 34:769–773. 89. Wirtitsch MG, Schmidinger G, Prskavec M, et al. Influence of blue-lightfiltering intraocular lenses on color perception and contrast acuity. Ophthalmology 2009; 116:39–45. 90. Turner PL, Mainster MA. Circadian photoreception: ageing and the eye’s important role in systemic health. Br J Ophthalmol 2008; 92:1439–1444. 91. Foley D, Ancoli-Israel S, Britz P, Walsh J. Sleep disturbances and chronic disease in older adults: results of the 2003 National Sleep Foundation Sleep in America Survey. J Psychosom Res 2004; 56:497–502. 92. Landers J, Tamblyn D, Perriam D. Effect of a blue-light-blocking intraocular lens on the quality of sleep. J Cataract Refract Surg 2009; 35:83–88. 93. Brondsted AE, Lundeman JH, Kessel L. Short wavelength light filtering by the && natural human lens and IOLs – implications for entrainment of circadian rhythm. Acta Ophthalmol 2013; 91:52–57. This article explored the effects of aging crystalline lenses and several intraocular lenses on the photoentrainment of the circadian rhythm. They showed that all of the intraocular lenses (UV, violet-blocking, and blue-blocking) had a minimal effect on melanopsin activation, whereas older human lenses had a significant detrimental effect.
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Ultraviolet-blocking intraocular lenses: fact or fiction Edward Lai, Benjamin Levine, and Jessica Ciralsky
Purpose of review Ultraviolet-blocking intraocular lenses (IOLs) are used routinely in cataract surgery and are widely accepted. Blue-blocking IOLs, however, have been much debated since their inception. In this article, we will review the advantages and disadvantages of blue-blocking IOLs. Recent findings In experimental and animal studies, acute blue light exposure induces retinal damage and the use of blue-blocking IOLs lessens this damage. Many large epidemiologic studies have further investigated this relationship between blue light exposure and the development of age-related macular degeneration, and have shown conflicting results. Visual performance and circadian rhythm disturbances have also been explored in patients with blue-blocking IOLs; no significant negative effects have been shown. Summary The current literature on blue-blocking IOLs is contradictory. Studies have failed to conclusively prove that blue-blocking lenses provide photoprotection against age-related macular degeneration or cause any significant detrimental effects on visual function or circadian rhythms. Keywords age-related macular degeneration, blue-blocking intraocular lens, circadian rhythm, scotopic sensitivity, ultraviolet-blocking intraocular lens
INTRODUCTION The human eye is naturally designed to block harmful ultraviolet (UV) light. The retina’s first line of defense against phototoxic damage is the cornea and crystalline lens. The cornea blocks UV wavelengths below 300 nm, and the natural crystalline lens blocks UV wavelengths in the 300–400 nm range [1–5]. With age, the crystalline lens yellows, resulting in increased absorption of UV light, particularly in the blue portion of the spectrum [1–4,6–8]. When the natural crystalline lens is removed during cataract surgery, its protective effects are lost and the retina’s exposure to harmful blue light is increased. Intraocular lens (IOL) design has been modified over the years to try to simulate these protective properties of the natural crystalline lens. The earliest IOL implants allowed unrestricted UV and visible light to penetrate the eye [5,9]. In the mid-1980s, prompted by the concern that UV light could damage the retina, IOL implants began to incorporate UV radiation blocking chromophores [5,10]. Particular concern over the possible retinal toxicity from short wavelengths of visible light [11] led to the development
and adoption of the blue-blocking IOLs in the 1990s. There has been wide acceptance and little controversy surrounding the use of UV-blocking IOLs, especially as UV radiation is unnecessary for vision. Blue-blocking IOLs, on the other hand, have been much debated since their inception. There is no question that blue-blocking IOLs decrease the exposure of the retina to wavelengths of light in the blue spectrum; however, the increased photoprotective effect of these lenses remains in question. Advocates for the use of blue-blocking lenses cite its theoretical ability to decrease the risk of agerelated macular degeneration without compromising the visual acuity, color vision, scotopic vision, or contrast sensitivity [12–15]. Adversaries claim that blue-blocking lenses cause poorer scotopic vision Weill Cornell Medical College, New York, New York, USA Correspondence to Jessica Ciralsky, MD, Weill Cornell Medical College, 1305 York Avenue, 11th Floor, New York, NY 10021, USA. Tel: +1 646 962 2020; fax: +1 646 962 0603; e-mail: [email protected] Curr Opin Ophthalmol 2014, 25:35–39 DOI:10.1097/ICU.0000000000000016
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KEY POINTS The phototoxicity–age-related macular degeneration hypothesis is based on experimental and animal studies; large epidemiological studies have failed to conclusively prove this association. Most studies conducted have reported no significant changes in terms of color vision or contrast sensitivity with blue-blocking lenses; the only two studies to the contrary had nonsignificant findings. Given the great improvement in light transmission achieved simply by removing the cataract, it seems unlikely that blue-blocking intraocular lenses cause any significant disruptions to the circadian rhythm.
and disruption of circadian rhythms without providing any proven photoprotection against agerelated macular degeneration [16–19]. Many studies have been published in response to the blue-blocking debate; yet, there still seems to be a lack of consensus for or against their use among eye care professionals. In this article, we will review the major controversies associated with blue-blocking IOLs.
ULTRAVIOLET LIGHT PHOTOTOXICITY AND BLUE-BLOCKING INTRAOCULAR LENS RETINAL PHOTOPROTECTION Age-related macular degeneration affects 11.5% of the population in the USA and is one of the leading causes of blindness in the developed world [20,21]. With the aging general population, the incidence of age-related macular degeneration will increase considerably, likely doubling in the next 20 years [20,21]. This growing burden on patients and society has prompted the search for better treatments and prevention measures. Several experimental and animal studies have shown the danger of light exposure, particularly in the short wavelength spectrum, on the retina [11,22–26]. The biological basis of these experiments is thought to be blue-light-induced apoptosis of the retinal pigment epithelium, mediated by the lipofuscin fluorophore A2E [27,28]. These studies provide convincing evidence that blue light exposure can damage the retina in experimental and animal models; the implication for retinal damage in humans from long-term, low-intensity light exposure, however, is unclear. Many epidemiologic studies, both populationbased and case–control studies, have examined the association between exposure to environmental 36
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light and the development or progression of agerelated macular degeneration. A positive association between light exposure and age-related macular degeneration has been shown in quite a few studies [29–35], including a study by Taylor et al. [31], who found that patients with advanced age-related macular degeneration had a 48% higher exposure to blue light during the previous 20 years than controls. One additional study by Fletcher et al. [35] only showed an increased risk of age-related macular degeneration in the subset of patients with low antioxidant levels. A number of other large studies failed to find an association between light exposure and age-related macular degeneration [36–43]. The existing evidence is difficult to interpret, given the widely variable and conflicting data. Part of the problem stems from the fact that it is very challenging to determine a patient’s cumulative light exposure retrospectively. Additionally, agerelated macular degeneration is a multifactorial disease involving many variables including genetics, smoking, diet, and geographic location, making the analysis of one association more difficult [29]. Age-related macular degeneration development and progression has also been linked to cataract surgery. This linkage is based on the hypothesis that removal of the cataractous crystalline lens, which blocked a significant amount of blue light, allows more harmful blue light to reach the retina. A recent study by Klein et al. [44 ] evaluated the association between cataract, cataract surgery, and age-related macular degeneration over a 20-year interval. They did not find an association among cataract or cataract surgery and the development of early agerelated macular degeneration. They did, however, find that there was a positive association between cataract surgery and the incidence of late age-related macular degeneration, even after controlling for other risk factors. Several other studies have also supported a positive association reporting up to a 5.7-fold increase in the incidence of late-stage, agerelated macular degeneration in nonphakic vs. phakic individuals [44 ,45–54]. Conversely, many other studies have failed to find supporting evidence linking age-related macular degeneration to cataract surgery [40,55–59]. Furthermore, several studies have even shown a relationship between cataracts and age-related macular degeneration [46,47,54], making the previous results difficult to interpret. The possibility that blue-light exposure can increase the risk of age-related macular degeneration led to the development of blue-blocking, yellow tinted IOLs. Many studies have examined the transmittance spectrum of different available IOLs [9,60,61,62 ]. A recent report by Tanito et al. [62 ] showed that yellow tinted IOLs absorb more &&
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Ultraviolet-blocking intraocular lenses Lai et al.
blue light than clear IOLs and aphakic eyes. They showed that yellow tinted IOLs reduced blue-light irradiance by 62–82%, whereas clear UV-blocking lenses only provided reductions of 43–64%. To further explore this subject, several studies tested the ability of yellow filters to lessen the induced retinal damage previously shown in the experimental models [63–67]. Sparrow et al. [63] exposed cultured human retinal pigment epithelial cells to blue light in the presence or absence of an IOL. They showed a protective effect of blue-blocking lenses against retinal pigment epithelial cell death. The phototoxicity–age-related macular degeneration hypothesis is still very controversial. Experimental models show obvious retinal damage from high-intensity blue-light exposure and reduced retinal damage with the introduction of blue-blocking IOLs. The extrapolation of these findings to reallife scenarios, however, is unclear. Furthermore, large epidemiologic studies have reported contradictory findings. Several studies have shown a positive association between sunlight and age-related macular degeneration, and many other large studies have failed to find any correlation. Thus, the necessity of blue-blocking IOLs to decrease the risk of agerelated macular degeneration remains controversial and based mainly on theoretical protective properties.
SCOTOPIC SENSITIVITY AND VISUAL FUNCTION Scotopic sensitivity and night vision decline with age as the number of rod photoreceptors naturally decrease each year [68]. As night vision peaks at approximately 500 nm, IOLs that filter out blue light can theoretically reduce scotopic sensitivity and decrease dark adaptation [69,70]. A significant decrease in scotopic sensitivity and dark adaptation can be detrimental in an elderly population, and has been correlated with a risk of falling [71]. Many researchers have compared scotopic sensitivity with blue-blocking and UV-blocking lenses. A few studies have found a decrease in scotopic sensitivity, by approximately 14–21%, when a blue-blocking lens was used [5,69,70,72]. Two additional studies also showed decreased scotopic sensitivity with the use of blue-blocking IOLs; however, they reported that the clinical effects were negligible [73,74]. Several other studies failed to find any decreased scotopic sensitivity with the use of blue-blocking lenses [75,76]. If scotopic sensitivity is indeed reduced, the clinical significance is likely minimal. Concern over the loss of contrast sensitivity and color vision with blue-blocking IOLs has also been raised. Many studies have explored this subject
in detail, and most have shown comparable results with blue-blocking and UV-blocking IOLs in terms of color vision and contrast sensitivity [75–85]. A few studies have even showed improved contrast sensitivity with blue-blocking IOLs [86,87]. Schmidinger et al. [88] showed that although there were no significant differences in color vision, two patients reported minor subjective color changes, although neither patient required explantation of the IOL. Another study by Wirtitsch et al. [89] found that patients with blue-blocking IOLs had worse contrast acuity compared with patients with UVblocking IOLs; the differences, though, were small and of unclear significance. The majority of the studies conducted have reported no significant changes in terms of color vision or contrast sensitivity with blue-blocking lenses. Only two studies to the contrary had nonsignificant findings.
CIRCADIAN CYCLE Behavioral adjustment to ambient light is a fundamental aspect of life. In 2002, blue-light-sensitive nonvisual ganglion cells in the retina were discovered. They contain melanopsin, a photopigment with maximal sensitivity in the blue portion of the spectrum. These ganglion cells respond directly to blue light stimulation and are thought to play a critical role in maintaining effective circadian photoentrainment [90]. They help control the biological clock through suppression of melatonin secretion [90]. In darkness, the pineal gland secretes melatonin and causes sleepiness; in bright light, melatonin is suppressed leading to increased alertness. Previous reports have shown that the prevalence of circadian disorders increases with age [91]. Part of this phenomenon may be due to the fact that there is a decreased amount of light reaching the visual system as we age, secondary to pupillary miosis and yellowing of the human crystalline lens. Cataract surgery improves the overall light transmission to the retina and has been shown to improve a patient’s sleep pattern. Concerns about the possible negative effects on the circadian rhythms with the use of blue-blocking lenses have been expressed. Mainster [5] showed that blue-blocking lenses decrease melatonin suppression by 27–38% compared with UV-blocking lenses. A study by Landers et al. [92], however, showed that the use of blueblocking IOLs had no detrimental effects on the quality of sleep. A recent study by Brondsted et al. [93 ] explored the effects of aging crystalline lenses and several different IOLs on the photoentrainment of the circadian rhythm. They showed that all of the IOLs (UV, violet-blocking, and blue-blocking) had a
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minimal effect on melanopsin activation, whereas older human lenses had a significant effect. Given the great improvement in light transmission simply by removing the cataract, it seems unlikely that blue-blocking IOLs cause any significant disruption to the circadian rhythm.
CONCLUSION The ideal IOLs should have a photoprotective effect against all harmful wavelengths of light, while maintaining optimal visual performance in photopic as well as scotopic environments. Review of the current literature shows that the relationship of blue light exposure to the development and progression of agerelated macular degeneration remains inconclusive, as does the association between cataract surgery and age-related macular degeneration. In addition, the majority of the literature states that there are no detrimental effects of blue-blocking IOLs on scotopic visual function or circadian rhythms, although there are a few studies to the contrary. There has been limited new information published on this topic in the last year. In order to definitively answer the questions surrounding the possible benefits and detriments of blue-blocking IOLs, prospective, randomized trials are necessary. It is the responsibility of every cataract surgeon to be familiar with the wide variety of available IOLs and to select the implant best suited for each individual patient. Acknowledgements None. Conflicts of interest The work of E.L., B.L., and J.C. is supported by a grant from Research to Prevent Blindness. There are no conflicts of interest.
REFERENCES AND RECOMMENDED READING Papers of particular interest, published within the annual period of review, have been highlighted as: & of special interest && of outstanding interest 1. Cuthbertson FM, Peirson SN, Wulff K, et al. Blue light-filtering intraocular lenses: review of potential benefits and side effects. J Cataract Refract Surg 2009; 35:1281–1297. 2. Boettner EA, Wolter JR. Transmission of the ocular media. Invest Ophthalmol 1962; 1:776–783. 3. Norren DV, Vos JJ. Spectral transmission of the human ocular media. Vision Res 1974; 14:1237–1244. 4. Mellerio J. Yellowing of the human lens: nuclear and cortical contributions. Vision Res 1987; 27:1581–1587. 5. Mainster MA. Violet and blue light blocking intraocular lenses: photoprotection versus photoreception. Br J Ophthalmol 2006; 90:784–792. 6. Mainster MA. Intraocular lenses should block UV radiation and violet but not blue light. Arch Ophthalmol 2005; 123:550–555. 7. Bron AJ, Vrensen GF, Koretz J, et al. The ageing lens. Ophthalmologica 2000; 214:86–104.
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8. Weale RA. Age and the transmittance of the human crystalline lens. J Physiol 1988; 395:577–587. 9. Mainster MA. Spectral transmittance of intraocular lenses and retinal damage from intense light sources. Am J Ophthalmol 1978; 85:167–170. 10. Mainster MA. The spectra, classification, and rationale of ultraviolet-protective intraocular lenses. Am J Ophthalmol 1986; 102:727–732. 11. Ham WT, Mueller HA, Sliney DH. Retinal sensitivity to damage from short wavelength light. Nature 1976; 260:153–155. 12. Symes RJ, Cuthbertson FM. Blue-blocking intraocular implants should be used routinely during phacoemulsification surgery – yes. Eye 2012; 26:1397–1399. 13. Henderson BA, Grimes KJ. Blue-blocking IOLs: a complete review of the literature. Surv Ophthalmol 2010; 55:284–289. 14. Braunstein RE, Sparrow JR. A blue-blocking intraocular lens should be used in cataract surgery. Arch Ophthalmol 2005; 123:547–549. 15. Lee RMH, Cuthbertson FM, Soderberg P, Liu CS. A possible strategy for implanting blue-blocking intraocular lenses. Acta Ophthalmol 2012; 90:e151. 16. Lee RMH, Lam FC, Liu CSC. Blue-blocking intraocular implants should be used routinely during phacoemulsification surgery – no. Eye 2012; 26: 1400–1401. 17. Mainster MA, Turner PT. Blue-blocking intraocular lenses: myth or reality? Am J Ophthalmol 2009; 147:8–10. 18. Mainster MA, Turner PL. Blue-blocking IOLs vs. short-wavelength visible light: hypothesis-based vs evidence-based medical practice. Ophthalmology 2011; 118:1–2. 19. Mainster MA, Turner PL. Blue-blocking IOLs decrease photoreception without providing significant photoprotection. Surv Ophthalmol 2010; 55:272– 283. 20. Friedman DS, O’Colmain BJ, Munoz B, et al., Eye Disease Prevalence Research Group. Prevalence of age-related macular degeneration in the United States. Arch Ophthalmol 2004; 122:564–572. 21. Wong IYH, Koo SCY, Chan CWN. Prevention of age-related macular degeneration. Int Ophthalmol 2011; 31:73–82. 22. Gorgels GMF, Van Norren D. Ultraviolet and green light cause different types of damage in rat retina. Invest Ophthalmol Vis Sci 1995; 36:851–863. 23. Noell WK, Walker VS, Kang BS, et al. Retinal damage by light in rats. Invest Ophthalmol 1966; 5:450–473. 24. Van Norren D, Schellekens P. Blue light hazard in rat. Vision Res 1990; 30:1517–1520. 25. Grimm C, Wenzel A, Williams TP, et al. Rhodopsin-mediated blue-light damage to the rat retina: effect of photoreversal of bleaching. Invest Ophthalmol Vis Sci 2001; 42:497–505. 26. Ham WT Jr, Ruffolo JJ Jr, Mueller HA, et al. Histologic analysis of photochemical lesions produced in rhesus retina by short wave-length light. Invest Ophthalmol Vis Sci 1978; 1:1029–1035. 27. Sparrow JR, Nakanishi K, Parish CA. The lipofuscin fluorophore A2E mediates blue light-induced damage to retinal pigment epithelial cells. Invest Ophthalmol Vis Sci 2000; 41:1981–1989. 28. Hunter JJ, Morgan JIW, Merigan WH, et al. The susceptibility of the retina to photochemical damage from visible light. Prog Retin Eye Res 2012; 31:28– 42. 29. Tomany SC, Cruickshanks KJ, Klein R, et al. Sunlight and the 10-year incidence of age-related maculopathy: the Beaver Dam Eye Study. Arch Ophthalmol 2004; 122:750–757. 30. Taylor HR, Munoz B, West S, et al. Visible light and risk of age-related macular degeneration. Trans Am Ophthalmol Soc 1990; 88:163–173. 31. Taylor H, West S, Munoz B, et al. The long-term effects of visible light on the eye. Arch Ophthalmol 1992; 110:99–104. 32. Cruickshanks KJ, Klein R, Klein BE. Sunlight and age-related macular degeneration. The Beaver Dam Eye Study. Arch Ophthalmol 1993; 111: 514–518. 33. Cruickshanks KJ, Klein R, Klein BE, Nondahl DM. Sunlight and the 5-year incidence of early age-related maculopathy: the Beaver Dam Eye Study. Arch Ophthalmol 2001; 119:246–250. 34. Hirakawa M, Tanaka M, Tanaka Y, et al. Age-related maculopathy and sunlight exposure evaluated by objective measurement. Br J Ophthalmol 2008; 92:630–634. 35. Fletcher AE, Bentham GC, Agnew M, et al. Sunlight exposure, antioxidants, and age-related macular degeneration. Arch Ophthalmol 2008; 126:1396– 1403. 36. Darzins P, Mitchell P, Heller RF. Sun exposure and age-related macular degeneration: an Australian case–control study. Ophthalmology 1997; 104:770–776. 37. McCarty CA, Mukesh BN, Fu CL, et al. Risk factors for age-related maculopathy: the Visual Impairment Project. Arch Ophthalmol 2001; 119:1455– 1462. 38. Delcourt C, Carriere I, Ponton-Sanchez A, et al. Light exposure and the risk of age-related macular degeneration: the Pathologies Oculaires Liees a I’Age (POLA) study. Arch Ophthalmol 2001; 119:1463–1468. 39. Hirvela H, Luukinen H, Laara E, et al. Risk factors of age-related maculopathy in a population 70 years of age or older. Ophthalmology 1996; 103:871– 877. 40. Clemons TE, Milton RC, Klein R, et al. Risk factors of the incidence of advanced age-related macular degeneration in the Age-Related Eye Disease Study (AREDS). AREDS report no. 19. Ophthalmology 2005; 112:533–539.
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Ultraviolet-blocking intraocular lenses Lai et al. 41. Risk factors for neovascular age-related macular degeneration. The Eye Disease Case–Control Study Group. Arch Ophthalmol 1992; 110:1701–1708. 42. Khan JC, Shahid H, Thurlby DA, et al. Age related macular degeneration and sun exposure, iris colour, and skin sensitivity to sunlight. Br J Ophthalmol 2006; 90:29–32. 43. West SK, Rosenthal FS, Bressler NM, et al. Exposure to sunlight and other risk factors for age-related macular degeneration. Arch Ophthalmol 1989; 107:875–879. 44. Klein BE, Howard KP, Lee KE, et al. The relationship of cataract and cataract && extraction to age-related macular degeneration: the Beaver Dam Eye Study. Ophthalmology 2012; 119:1628–1633. This article evaluated the associations among cataract, cataract surgery, and agerelated macular degeneration over a 20-year interval. They found a positive association between cataract surgery and the incidence of late age-related macular degeneration, even after controlling for other risk factors. 45. Pollack A, Marcovich A, Bukelman A, Oliver M. Age-related macular degeneration after extracapsular cataract extraction with intraocular lens implantation. Ophthalmology 1996; 103:1546–1554. 46. Chaine G, Hullo A, Sahel J, et al. Case–control study of the risk factors for age related macular degeneration France-DMLA Study Group. Br J Ophthalmol 1998; 82:996–1002. 47. Klein R, Klein BE, Wong TY, et al. The association of cataract and cataract surgery with the long-term incidence of age-related maculopathy: the Beaver Dam Eye Study. Arch Ophthalmol 2002; 120:1551–1558. 48. Wang JJ, Klein R, Smith W, et al. Cataract surgery and the 5-year incidence of late-stage age-related maculopathy: pooled findings from the Beaver Dam and Blue Mountain Eye studies. Ophthalmology 2003; 110:1960–1967. 49. Klein R, Klein BE, Jensen SC, Cruickshanks KJ. The relationship of ocular factors to the incidence and progression of age-related maculopathy. Arch Ophthalmol 1998; 116:506–513. 50. Cugati S, Mitchell P, Rochtchina E, et al. Cataract surgery and the 10-year incidence of age-related maculopathy: the Blue Mountains Eye Study. Ophthalmology 2006; 113:2020–2025. 51. Chakravarthy U, Wong TY, Fletcher A, et al. Clinical risk factors for age-related macular degeneration: a systematic review and meta-analysis. BMC Ophthalmol 2010; 10:31. 52. Ho L, Boekhoorn SS, Liana van Duijn CM, et al. Cataract surgery and the risk of aging macula disorder: the Rotterdam study. Invest Ophthalmol Vis Sci 2008; 49:4795–4800. 53. Bockelbrink A, Roll S, Ruether K, et al. Cataract surgery and the development or progression of age-related macular degeneration: a systematic review. Surv Ophthalmol 2008; 53:359–367. 54. Freeman EE, Munoz B, West SK, et al. Is there association between cataract surgery and age-related macular degeneration? Data from three population based studies. Am J Ophthalmol 2003; 135:849–856. 55. Armbrecht AM, Findlay C, Aspinall PA, et al. Cataract surgery in patients with age-related macular degeneration: one-year outcomes. J Cataract Refract Surg 2003; 29:686–693. 56. Sutter FK, Menghini M, Barthelmes D, et al. Is pseudophakia a risk factor for neovascular age-related macular degeneration? Invest Ophthalmol Vis Sci 2007; 48:1472–1475. 57. Xu L, Li Y, Zheng Y, Jonas JB. Associated factors for age related maculopathy in the adult population in China: the Beijing Eye Study. Br J Ophthalmol 2006; 90:1087–1090. 58. Baatz H, Darawsha R, Ackermann H, et al. Phacoemulsification does not induce neovascular age-related macular degeneration. Invest Ophthalmol Vis Sci 2008; 49:1079–1083. 59. Chew EY, Sperduto RD, Milton RC, et al. Risk of advanced age-related macular degeneration after cataract surgery in the Age-Related Eye Diseases Study: AREDS report 25. Ophthalmology 2009; 116:297–303. 60. Brockmann C, Schulz M, Laube T. Transmittance characteristics of ultraviolet and blue-light-filtering intraocular lenses. J Cataract Refract Surg 2008; 34:1161–1166. 61. Tanito M, Okuno T, Ishiba Y, Ohira A. Transmission spectrums and retinal blue-light irradiance values of untinted and yellow-tinted intraocular lenses. J Cataract Refract Surg 2010; 36:299–307. 62. Tanito M, Okuno T, Ishiba Y, Ohira A. Measurements of transmission spectrums & and estimation of retinal blue-light irradiance values of currently available clear and yellow-tinted intraocular lenses. Jpn J Ophthalmol 2012; 56:82–90. This article compared the most recent spectral transmission characteristics of available intraocular lenses. Yellow tinted intraocular lenses reduced blue-light irradiance by 62–82%, whereas clear ultraviolet-blocking lenses only provided reductions of 43–64%. 63. Sparrow JR, Miller AS, Zhou J. Blue light-absorbing intraocular lens and retinal pigment epithelium protection in vitro. J Cataract Refract Surg 2004; 30:873– 878. 64. Mukai K, Matsushima H, Sawano M, et al. Photoprotective effect of yellowtinted intraocular lenses. Jpn J Ophthalmol 2009; 53:47–51. 65. Yanagi Y, Inoue Y, Iriyama A, Jang WD. Effects of yellow intraocular lenses on light-induced upregulation of vascular endothelial growth factor. J Cataract Refract Surg 2006; 32:1540–1544.
66. Tanito M, Kaidzu S, Anderson RE. Protective effects of soft acrylic yellow filter against blue light-induced retinal damage in rats. Exp Eye Res 2006; 83:1493–1504. 67. Nilsson SE, Textorius O, Andersson BE, Swenson B. Clear PMMA versus yellow intraocular lens material. An electrophysiologic study on pigmented rabbits regarding ‘the blue light hazard’. Prog Clin Biol Res 1989; 314:539– 553. 68. Jackson GR, Owsley C, Curcio CA. Photoreceptor degeneration and dysfunction in aging and age-related maculopathy. Ageing Res Rev 2002; 1:381–396. 69. Mainster MA, Sparrow JR. How much blue light should an IOL transmit. Br J Ophthalmol 2003; 87:1523–1529. 70. Schwiegerling J. Blue-light-absorbing lenses and their effect on scotopic vision. J Cataract Refract Surg 2006; 32:141–144. 71. McMurdo ME, Gaskell A. Dark adaptation and falls in the elderly. Gerontology 1991; 37:221–224. 72. Pons A, Delgado D, Campos J. Determination of the action spectrum of the blue-light hazard for different intraocular lenses. J Opt Soc Am A Opt Image Sci Vis 2007; 24:1545–1550. 73. Werner JS. Night Vision in the elderly: consequences for seeing through a ‘blue filtering’ intraocular lens. Br J Ophthalmol 2005; 89:1518–1521. 74. Kiser AK, Deschler EK, Dagnelie G. Visual function and performance with blue-light blocking filters in age-related macular degeneration. Clin Exp Ophthalmol 2008; 36:514–520. 75. Greenstein VC, Chiosi F, Baker P, et al. Scotopic sensitivity and color vision with a blue-light-absorbing intraocular lens. J Cataract Refract Surg 2007; 33:667–672. 76. Muftuoglu O, Karel F, Duman R. Effect of a yellow intraocular lens on scotopic vision, glare disability and blue color perception. J Cataract Refract Surg 2007; 33:658–666. 77. Hayashi K, Hayashi H. Visual function in patients with yellow tinted intraocular lenses compared with vision in patients with nontinted intraocular lenses. Br J Ophthalmol 2006; 90:1019–1023. 78. Landers J, Tan TH, Yuen J, Liu H. Comparison of visual function following implantation of AcrySof natural intraocular lenses with conventional intraocular lenses. Clin Exp Ophthalmol 2007; 35:152–159. 79. Rodriguez-Galietero A, Montes-Mico R, Munoz G, Albarran-Diego C. Comparison of contrast sensitivity and color discrimination after clear and yellow intraocular lens implantation. J Cataract Refract Surg 2005; 31:1736– 1740. 80. Marshall J, Cionni RJ, Davison J, et al. Clinical results of the blue-light filtering AcrySof Natural foldable acrylic intraocular lens. J Cataract Refract Surg 2005; 31:2319–2323. 81. Raj SM, Vasavada AR, Nanavaty MA. AcrySof Natural SN60AT versus AcrySof SA60AT intraocular lens in patients with color vision defects. J Cataract Refract Surg 2005; 31:2324–2328. 82. Cionni RJ, Tsai JH. Color perception with AcrySof natural and AcrySof singlepiece intraocular lenses under photopic and mesopic conditions. J Cataract Refract Surg 2006; 32:236–242. 83. Bhattacharjee H, Bhattacharjee K, Medhi J. Visual performance: comparison of foldable intraocular lenses. J Cataract Refract Surg 2006; 32:451–455. 84. Vuori ML, Mantyjarvi M. Colour vision and retinal nerve fibre layer photography in patients with an AcrySof natural intraocular lens. Acta Ophthalmol Scand 2006; 84:92–94. 85. Leibovitch I, Lai T, Porter N, et al. Visual outcomes with the yellow intraocular lens. Acta Ophthalmol Scand 2006; 84:95–99. 86. Yuan Z, Reinach P, Yuan J. Contrast sensitivity and color vision with a yellow intraocular lens. Am J Ophthalmol 2004; 138:138–140. 87. Niwa K, Yoshino Y, Okuyama F, Tokoro T. Effects of tinted intraocular lens on contrast sensitivity. Ophthalmic Physiol Opt 1996; 16:297–302. 88. Schmidinger G, Menapace R, Pieh S. Intraindividual comparison of color contrast sensitivity in patient with clear and blue-light-filtering intraocular lenses. J Cataract Refract Surg 2008; 34:769–773. 89. Wirtitsch MG, Schmidinger G, Prskavec M, et al. Influence of blue-lightfiltering intraocular lenses on color perception and contrast acuity. Ophthalmology 2009; 116:39–45. 90. Turner PL, Mainster MA. Circadian photoreception: ageing and the eye’s important role in systemic health. Br J Ophthalmol 2008; 92:1439–1444. 91. Foley D, Ancoli-Israel S, Britz P, Walsh J. Sleep disturbances and chronic disease in older adults: results of the 2003 National Sleep Foundation Sleep in America Survey. J Psychosom Res 2004; 56:497–502. 92. Landers J, Tamblyn D, Perriam D. Effect of a blue-light-blocking intraocular lens on the quality of sleep. J Cataract Refract Surg 2009; 35:83–88. 93. Brondsted AE, Lundeman JH, Kessel L. Short wavelength light filtering by the && natural human lens and IOLs – implications for entrainment of circadian rhythm. Acta Ophthalmol 2013; 91:52–57. This article explored the effects of aging crystalline lenses and several intraocular lenses on the photoentrainment of the circadian rhythm. They showed that all of the intraocular lenses (UV, violet-blocking, and blue-blocking) had a minimal effect on melanopsin activation, whereas older human lenses had a significant detrimental effect.
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