Yellow Intraocular Lens Research Articles

Drusen classification and quantification in pseudophakic postmortem eyes implanted with or without blue-light filtering intraocular lenses

Abstract Purpose: To investigate the effect of blue-light filtering intraocular lenses on drusen formation in postmortem eyes via histopathological analysis. Materials and Methods: One hundred and ninety-three postmortem pseudophakic eyes (100 with a clear intraocular lenses [cIOL] and 93 with a yellow, yellow intraocular lenses [yIOL]) were obtained from the Lions Gift of Sight eye bank. Sex, age-at-surgery, age-at-death, surgery-to-death time, and clinical history were collected. Eyes were sectioned on their coronal and sagittal axes, and formalin-fixed paraffin-embedded macular cross sections were obtained. Sections were stained with hematoxylin and eosin and scanned with the Zeiss Axio Scan. Z1 scanner. Drusen were classified by type, size or subtype, and quantity. Results: Large, soft drusen were present in 49% (n = 95) of eyes, 9% (n = 17) had cuticular drusen, 16% (n = 30) had hard drusen, and 26% (n = 51) had no drusen. There were significantly more cIOL eyes with large, soft drusen (P < 0.001). There were significantly more yIOL eyes with no drusen (P < 0.0001). No significant differences in the presence of hard or cuticular drusen were found. yIOL eyes had significantly higher mean age-at-surgery (P < 0.001) and mean age-at-death (P < 0.05), while cIOL eyes had a significantly higher mean surgery-to-death time (P < 0.05). Finally, significantly more yIOL eyes had a history of smoking (P < 0.01) and hypertension (P < 0.05), while significantly more cIOL eyes had a history of glaucoma (P < 0.05). Conclusions: Large, soft drusen were significantly less prevalent in yIOL eyes than in cIOL eyes and significantly more yIOL eyes had no drusen. These findings suggest that yIOLs may prevent the incidence and development of age-related macular degeneration after cataract surgery.

Blue illusions on slit-lamp microscopy through yellow intraocular lens explained

Blue illusions on slit-lamp microscopy through yellow intraocular lens explained

Evaluation of a Novel Non-Diffractive Extended Depth of Focus Intraocular Lens – First Results from a Prospective Study

Purpose To evaluate a novel hydrophobic, non-diffractive, extended depth of focus (EDOF) intraocular lens (IOL) design in comparison to two monofocal aspheric lenses. Methods Inclusion criteria for this prospective, monocentric cohort study were opacification of the crystalline lens and patients’ wishes for surgery. In the case of the EDOF IOL, patients asked for a presbyopia correction. All patients received surgery on both eyes. Corrected and uncorrected distance visual acuity (CDVA, UCDVA), uncorrected and distance corrected intermediate visual acuity (UIVA, DCIVA) and defocus curves (all monocular and binocular) were compared three months postoperatively. Results Fifty-six eyes were implanted with an EDOF IOL (LuxSmartTM, Bausch & Lomb GmbH, Berlin, Germany), 50 eyes with a monofocal aspheric IOL: 32 eyes with a clear IOL (Polylens® AS 61, Polytech Domilens, Roßdorf, Germany), 16 eyes with a yellow IOL (iSert® 251, Hoya Surgical Optics GmbH, Frankfurt, Germany). Three months postoperatively, UCDVA was comparable with the EDOF IOL, versus the monofocal IOL (P > 0.9). Binocular DCIVA in the EDOF IOL was significantly higher than in the monofocal IOL (P = 0.001). Monocular DCIVA better than 20/23 Snellen was achieved in 10% with the monofocal IOL and in 68% (P < 0.0001) with the EDOF IOL. Defocus curves showed a depth of focus at 20/23 Snellen of 1.6 vs. 0.83 diopters (D) in the EDOF IOL, vs. the monofocal IOL. No patient reported halos or starbursts in non-standardized questioning. Conclusion This non-diffractive EDOF IOL provided comparably high UCDVA and significantly higher DCIVA than the mono-focal lenses, causing only mild optical phenomena.

Does Every Calculation Formula Fit for All Types of Intraocular Lenses? Optimization of Constants for Tecnis ZA9003 and ZCB00 Is Necessary.

Background and Objectives: To evaluate the performance of intraocular lenses (IOLs) using power calculation formulas on different types of IOL. Materials and Methods: 120 eyes and four IOL types (BioLine Yellow Accurate Aspheric IOL (i-Medical), TECNIS ZCB00, TECNIS ZA9003 (Johnson & Johnson) (3-piece IOL) and Softec HD (Lenstec)) were analyzed. The performance of Haigis, Barret Universal II and SKR-II formulas were compared between IOL types. The mean prediction error (ME) and mean absolute prediction error (MAE) were analyzed. Results: The overall percentage of eyes predicted within ±0.25 diopters (D) was 40.8% for Barret; 39.2% Haigis and 31.7% for SRK-II. Barret and Haigis had a significantly lower MAE than SRK-II (p < 0.05). The results differed among IOL types. The largest portion of eyes predicted within ±0.25 D was with the Barret formula in ZCB00 (33.3%) and ZA9003 (43.3%). Haigis was the most accurate in Softec HD (50%) and SRK-II in Biolline Yellow IOL (50%). ZCB00 showed a clinically significant hypermetropic ME compared to other IOLs. Conclusions: In general, Barret formulas had the best performance as a universal formula. However, the formula should be chosen according to the type of IOL in order to obtain the best results. Constant optimizations are necessary for the Tecnis IOL ZCB00 and ZA9003, as all of the analyzed formulas achieved a clinically significant poor performance in this type of IOL. ZCB00 also showed a hypermetropic shift in ME in all the formulas.

Influence of Intraocular Lens Asphericity and Blue Light Filtering on Visual Outcome, Contrast Sensitivity, and Aberrometry after Uneventful Cataract Extraction.

Purpose To evaluate the effect of asphericity and blue light filter (BLF) of three different intraocular lenses (IOLs) on the visual performance, second- and third-order aberrations (defocus, coma, trefoil), and contrast sensitivity after uneventful cataract surgery.MethodsOne hundred and twenty eyes of 60 patients with clinically significant cataract were randomly assigned to receive one of the three IOL types: Bioline Yellow Accurate (aspheric, with BLF, i-medical, Germany), BioAcryl 60125 (spherical, without BLF, Biotech, France), and H65C/N (aspheric, without BLF, PhysIOL, Belgium). Each IOL was implanted in 40 eyes. Complete ophthalmologic examination, functional acuity contrast testing and wavefront analysis were performed 60 days postoperatively.Results The mean postoperative best-corrected visual acuity (BCVA) was 0.95 0.08, not differing statistically among the IOL groups (P = 0.83). Mean defocus and coma values did not yield any statistically significant difference through the IOL groups varying from –0.784 to –0.614 μm and 0.129 to 0.198 μm (P = 0.79 and 0.34, respectively). Bioline Yellow Accurate IOL presented less trefoil aberrations, 0.108 0.05 μm, compared to the other two IOL types (BioAcryl [0.206 0.19 μm] and Physiol [0.193 0.17 μm], P 0.05). Contrast sensitivity values did not differ among the groups under all lighting conditions. Bioline Yellow IOL showed a statistically higher loss of contrast sensitivity (between mesopic and mesopic with glare conditions) compared to the BioAcryl and PhysIOL in 12 and 3 cpd spatial frequencies, respectively (P 0.05).ConclusionBioline Yellow IOL indicated lower contrast sensitivity under mesopic conditions when glare was applied but resulted in less trefoil aberrations after uneventful cataract surgery. No further differences were noted in postoperative visual performance among three IOL groups.

Effects of Cataract Surgery on Melatonin Secretion in Adults 60 Years and Older

Cataract surgery, which increases perception of light, may increase melatonin secretion. Melatonin secretion has been associated with depression, diabetes, cognitive impairment, and breast cancer. To date, no evidence from a randomized clinical trial exists to support this cataract surgery hypothesis. To determine whether cataract surgery modifies the melatonin secretion at 3 months after cataract surgery in 169 adult patients. A parallel-group randomized clinical trial was conducted at a single referral center from July 1, 2014, to June 30, 2017. Data were analyzed from January 1, 2018, to March 31, 2019. Patients were aged 60 years or older, had no history of cataract surgery, and had cataracts with grade 2 or higher nuclear opacifications based on the Lens Opacities Classification System III. Analyses were based on intention to treat. Patients were randomized 1:1:1:1 to receive cataract surgery using artificial clear intraocular lens (IOL) or yellow IOL. Group 1 received prompt surgery with clear IOL, group 2, prompt surgery with yellow IOL, group 3, delayed surgery with clear IOL, and group 4, delayed surgery with yellow IOL. The intervention group consisted of groups 1 and 2, and the control group consisted of groups 3 and 4. Urinary melatonin excretion in the intervention group was measured at 3 months after surgery, and urinary melatonin excretion in the control group was measured before delayed surgery. Of the 169 randomized patients, 97 were men (57.4%). The mean (SD) age was 75.7 (6.7) years. Mean urinary melatonin excretion was calculated as standardized urinary concentration, the ratio of urinary concentration to urinary creatinine concentration (nanograms per milligram of creatinine), in the intervention group after cataract surgery. Mean urinary melatonin excretion was significantly higher than in the control group (adjusted mean difference of creatinine concentration, 0.159 log ng/mg, 95% CI, 0.045-0.273; P = .007) independent of baseline urinary melatonin excretion and potential confounders. Subgroup analysis comparing group 1 with group 3 revealed that concentration of urinary melatonin excretion in patients who received clear IOLs was higher than the control group by creatinine concentration 0.212 log ng/mg (95% CI of the difference, 0.058-0.365; P = .008). However, the difference between patients in group 2 and group 4 was not significant (adjusted mean difference for creatinine excretion, 0.083 log ng/mg, 95% CI, -0.087 to 0.253; P = .33). The difference of concentration of mean urinary melatonin excretion between patients in group 1 and those in group 2 was not significant (95% CI of the difference for creatinine concentration, -0.19 to 0.40 log ng/mg; P = .48). The findings in this study support the hypothesis that cataract surgery increases melatonin secretion. The effect of clear IOLs vs yellow IOLs on these outcomes was not shown to be different. UMIN-CTR Identifier: UMIN000014559.

Total Opacification of Intraocular Lens Implant After Uncomplicated Cataract Surgery: A Case Report

The introduction a few years ago of hydrophilic acrylic intraocular lenses (IOLs) a few years ago constituted a major advance in the field of Cataract Surgery. These lenses have become increasingly popular, thanks to the ease with which they can be folded and implanted in the capsular sac through a small incision; their good medium and long-term tolerance attributable to the great biocompatibility of the material employed; and the ease with which YAG laser capsulotomy can be performed where required, without damaging the lens and thus minimizing certain complications. Different models have been developed, generally offering good short- and middle-term vision performance, though little is known of their potential long-term results and complications.1 These complications include opacification of IOLs, which has been recognized for several years.3 Most reported cases have been late opacification of hydrophilic acrylic IOLs.4-10 Opacification reduces visual acuity (VA) and it requires some intervention. We report the clinical history and management of a cases of progressive opacification in hydrophilic yellow acrylic IOLs.

Intraocular lens power adjustment by a femtosecond laser: In vitro evaluation of power change, modulation transfer function, light transmission, and light scattering in a blue light–filtering lens

To evaluate intraocular lens (IOL) power, modulation transfer function (MTF), light transmission, and light scattering of a blue light-filtering IOL before and after power adjustment by a femtosecond laser obtained through increased hydrophilicity of targeted areas within the optic, creating the ability to build a refractive-index-shaping lens within an existing IOL. John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, USA. Experimental study. Ten CT Lucia 601PY single-piece yellow hydrophobic acrylic IOLs were used in this study. The IOL power and MTF were measured with a power and modulation transfer function device. Light transmission was measured using a Lambda 35 UV-VIS spectrophotometer. Backlight scattering was assessed with a Scheimpflug camera within the IOL substance. All measurements were done with hydrated IOLs. The IOLs were also evaluated under light microscopy (LM) before and after laser adjustment. After laser adjustment, a mean power change of -2.037 diopters was associated with a MTF change of -0.064 and a light transmittance change of -1.4%. Backlight scattering increased within the IOL optic in the zone corresponding to the laser treatment at levels that are not expected to be clinically significant. Treated areas within the optic could be well appreciated under LM without damage to the IOLs. Power adjustment of a commercially available hydrophobic acrylic blue light-filtering IOL by a femtosecond laser produced an accurate change in dioptric power while not significantly affecting the quality of the IOL.

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

ABSTRACTObjectives: 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.

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

BackgroundWith aging, the crystalline lens turns yellowish, which increases the absorption of wavelengths in the blue electromagnetic spectrum, reducing their photoreception in the retina. Since these wavelengths are the main stimulus in the regulation of the circadian rhythm, progressive reduction in their transmission is associated with chronic sleep disturbances and depression in elderly patients. Cataract extraction improves circadian photoreception at any age. However, lenses that block blue waves have 27% to 38% less melatonin suppression than lenses that block only ultraviolet (UV) rays.PurposeTo assess the depression symptoms in subjects who have had bilateral phacoemul-sification and intraocular lens (IOL) implants, one group with yellow chromophore IOLs and the other group with transparent IOLs were compared.SettingAssociation to Prevent Blindness in Mexico (APEC), Hospital “Dr Luis Sánchez Bulnes”.DesignThis was an observational, cross-sectional, and single-center study.Materials and methodsTwenty-six subjects between 60 and 80 years of age, with a history of bilateral phacoemulsification and placement of the same type of IOL in both eyes from 4 to 12 months prior to the study, who attended the follow-up visits and agreed to participate in this study, and provided signed informed consent were included in the study. They were asked to answer the short version of the 15-item Geriatric Depression Scale.ResultsThe average age of the study participants was 72.5±5.94 years. The group without chromophore included 46.1% (n=12) of the patients and the group with chromophore included 53.9% (n=14) of the patients (P=0.088).ConclusionIn the group of patients with IOLs that block the passage of blue light, the depression rate was 21.4%, a rate similar to that observed in the elderly population, whereas no patients in the group with transparent IOLs had depression.

Neutralization method for detecting the incidence of color perception changes after cataract surgery

To evaluate and compare the incidence of cyanopsia using the neutralization method in eyes in which clear or yellow intraocular lenses (IOLs) were implanted. Miyata Eye Clinic, Hiroshima, Japan. Retrospective comparative study. Patients who had cataract surgery with the implantation of a monofocal IOL were enrolled in the study. Group 1 had implantation of a clear IOL (Acrysof SA60AT, Sensar AR40e, N4-18B). Group 2 had implantation of a yellow IOL (AF-1 YA60BB, AN-6). A control group comprised healthy patients. The detection and degree of cyanopsia were evaluated using white gradation cards (1 white [W] and 5 white gradation cards with increasing intensity of yellow tint [Y1, Y2, Y3, Y4, and Y5]) (neutralization method). The study comprised 57 patients in Group 1, 96 in Group 2, and 41 in the control group. All patients in the control group selected the W, Y1, or Y2 cards as white. Cyanopsia was then defined as the perception of Y3, Y4, and Y5 as white. One month postoperatively, cyanopsia occurred significantly more frequently in Group 1 than in Group 2 (14.5% versus 4.9%) (P=.049). There was no significant difference at 3 months (9.1% versus 5.2%) (P > .05). In Group 1, cyanopsia was more frequent in eyes with monocular IOL implantation than in eyes with binocular IOL implantation (22.2% versus 2.7%; P = .035). The incidence of cyanopsia evaluated with the neutralization method was higher with clear IOLs than with yellow IOLs. In monocular implantation, yellow IOLs are recommended to avoid cyanopsia. The author has no financial or proprietary interest in any material or method mentioned.

Blue light-induced inflammatory marker expression in the retinal pigment epithelium-choroid of mice and the protective effect of a yellow intraocular lens material in vivo

Oxidative stress in the retinal pigment epithelium (RPE) is a well-accepted pathogenic change in vision-threatening diseases such as age-related macular degeneration. One source of oxidative stress is excessive light exposure, which causes excessive activation of the visual cycle. Because short wavelength light (blue light) has more energy, it is reported to be more harmful to photoreceptor cells than the other wavelengths of light. However, the biological effect of blue light in the RPE of living animals and the protective effect of a yellow intraocular lens (IOL) material that blocks blue light is still obscure. Therefore, we compared the pathogenic effect in the RPE-choroid complexes of mice exposed to light in a box made of a clear or a yellow IOL material. We measured the level of reactive oxygen species (ROS) using 2′, 7′-dichlorodihydrofluorescein diacetate, the mRNA levels of inflammatory cytokines and a macrophage marker by real-time polymerase chain reaction, and the protein level of monocyte chemotactic protein-1 (MCP-1) by ELISA. The ROS level after light exposure was suppressed in the RPE-choroids of light-exposed mice in the yellow IOL material box. In parallel, all the inflammatory cytokines that we measured and a macrophage marker were also suppressed in the RPE-choroids of light-exposed mice in the yellow IOL material box. Therefore, a yellow IOL material suppressed, and thus blue light exacerbated, the increase in the ROS level and inflammatory cytokine expression as well as macrophage recruitment in the RPE-choroid in vivo after light exposure.

Macular thickness measured by optical coherence tomography in pseudophakic eyes with clear vs yellow implant

ObjectiveTo study the use of optical coherence tomography (OCT), for measuring the macular thickness variations produced over time in elderly pseudophakic subjects implanted with a clear intraocular lens (IOL) in one eye, and a yellow IOL in the other eye. MethodsMacular thickness measurements were obtained in the 36 eyes of 18 subjects over 65 years, with cataracts surgically removed from both eyes and implanted with different absorbance (clear and yellow) IOLs in two separate surgeries. Stratus-OCT was used to determine the macular thickness in two sessions with 5 years of difference. ResultsAfter 5 years of follow-up, the eyes implanted with clear IOLs revealed a significant decrease in macular thickness. However, in eyes implanted with yellow IOLs the macular thickness remained stable. The mean overall decrease in macular thickness in eyes implanted with clear IOLs was 5±8μm (p=0.02), and foveal thickness reduction was 10±17μm (p=0.02). ConclusionsThe macular thickness changes produced in eyes implanted with a yellow IOL differ from those with a clear IOL. These observations point to a possible protective effect of yellow IOL against the harmful effects of light in elderly pseudophakic subjects. However, studies with a longer follow-up are still needed to confirm that the protection provided by this IOL model is clinically significant.

Espesor macular medido con tomografía de coherencia óptica en ojos pseudoafáquicos con implante amarillo vs. transparente

ObjectiveTo study the use of optical coherence tomography (OCT), for measuring the macular thickness variations produced over time in elderly pseudophakic subjects implanted with a clear intraocular lens (IOL) in one eye, and a yellow IOL in the other eye. MethodsMacular thickness measurements were obtained in the 36 eyes of 18 subjects over 65 years, with cataracts surgically removed from both eyes and implanted with different absorbance (clear and yellow) IOLs in 2 separate surgeries. Stratus-OCT was used to determine the macular thickness in 2 sessions with 5 years of difference. ResultsAfter 5 years of follow-up, the eyes implanted with clear IOLs revealed a significant decrease in macular thickness. However, in eyes implanted with yellow IOLs the macular thickness remained stable. The mean overall decrease in macular thickness in eyes implanted with clear IOLs was 5±8μm (P=.02), and foveal thickness reduction was 10±17μm (P=.02). ConclusionsThe macular thickness changes produced in eyes implanted with a yellow IOL differ from those with a clear IOL. These observation point to a possible protective effect of yellow IOL against the harmful effects of light in elderly pseudophakic subjects. However, studies with a longer follow-up are still needed to confirm that the protection provided by this IOL model is clinically significant.

The yellow intraocular lens and the natural ageing lens

The purpose of this study is to review and evaluate the advantages and disadvantages of blue light (400-480 nm) filtering intraocular lenses (IOLs) when compared with the ultraviolet (UV)-blocking IOLs. Theories that blue light could be related to the pathogenesis of age-related macular degeneration (AMD) have led to the use of yellow tinted IOLs in cataract surgery to filter short wavelength light. In spite of the potential benefits, some concerns have been raised. The potential advantages of the blue light filtering IOLs are that they could better mimic the conditions of phakia and therefore be more protective for the retina in decreasing the incidence of AMD. However, the potential disadvantages are that blue light filtering could negatively affect scotopic vision and circadian rhythms in older patients. These advantages and disadvantages of blue light filtering IOLs have not been proven clinically and thus many questions remain. Studies have shown that each type of IOL may have its own benefits and the type of IOL should be picked on the basis of patients' specific situations. In cataract surgery, considerations such as preexisting AMD, night vision problems or sleep problems may be considered with the choice of IOL.

Évaluation d’une nouvelle plateforme d’implant intraoculaire : centrage et stabilité rotatoire

To assess the rotational stability and centration of a single-piece hydrophilic acrylic intraocular lens (IOL) during the first postoperative year. Clinique Beausoleil, 117, avenue de Lodève, 34070 Montpellier, France. Retrospective case series. The POD AY 26% monofocal aspheric yellow intraocular lens is designed to facilitate its intraoperative orientation within the capsular bag. This study consists of a retrospective analysis of 117 consecutive eyes implanted with this IOL to determine its postoperative stability. Data collected include ocular biometry, patient history, IOL power, pre- and postoperative visual acuity and refraction, and slit lamp photos after one and three weeks, and 3 and 12 months. Mean postoperative visual acuity was 0.95 after 3 months and remained stable after 1 year. The refraction was also stable over time, although a slight effect related to corneal healing could be observed (0.1D). The mean absolute rotation of the implant was 2.5 ± 2.6°. The position of the center of the implant relative to the pupillary center expressed as a vector was 0.01 mm at 70°. This new IOL design is as stable as a C-Loop IOL but provides much better maneuverability during implantation. It provides physiologic centration and good rotational stability over 1 year. It would be a perfect platform for a toric optic.

Contrast sensitivity and color perception with orange and yellow intraocular lenses

To evaluate contrast sensitivity function (CSF) and color vision after implantation of either orange or yellow-tinted intraocular lenses (IOLs). Fifty-six eyes of 28 cataract patients who had bilateral implantation of orange-tinted (PC440Y Orange, Ophtec), yellow-tinted (AcrySof Natural SN60AT, Alcon), or clear (AcrySof SA60AT, Alcon) IOLs were examined. Six months postoperatively, monocular CSF under photopic and mesopic (with and without glare) conditions were measured using the Functional Visual Analyzer. Color discrimination was determined with the Farnsworth-Munsell 100-Hue test. Patients implanted with orange-tinted, yellow-tinted, or clear IOLs displayed similar CSF values, with no statistically significant differences at any spatial frequency (p>0.05). There were no statistically significant differences in chromatic discrimination among the 3 groups of patients (p>0.05). Orange or yellow blue-filtering IOL implantation is comparable to a clear IOL in terms of photopic and mesopic contrast sensitivity or color discrimination.

Influence of Blue Light-filtering Intraocular Lenses on Retinal Nerve Fiber Layer Measurements by Spectral-domain Optical Coherence Tomography

Purpose: The purpose of this study was to assess the influence of blue light-filtering intraocular lenses (IOL) on peripapillary retinal nerve fiber layer (RNFL) thickness measurements by spectral-domain (SD) optical coherence tomography (OCT).Methods: This prospective study included 50 eyes of 50 patients. Patients were randomly assigned to receive either a blue light-filtering IOL (acrysof IQ (SN60WF) [Alcon]) or a clear IOL (Tecnis (Z9003) [AMO]). The peripapillary RNFL thickness was measured using a Cirrus SD OCT before and 8 weeks after cataract surgery. Perioperative differences in RNFL thickness measurements and signal strengths (SS) were evaluated and compared in both IOL groups.Results: Thirty-nine eyes of 39 patients were included in the final analysis. There was a significant increase in average RNFL thickness and SS after cataract surgery in both IOL groups. No significant difference in perioperative changes of RNFL measurements was noted between yellow and clear IOL groups. In the multivariable analysis, the factor affecting perioperative differences of RNFL measurements was not IOL type but SS.Conclusions: Our data suggests that blue-light filtering IOL does not influence RNFL thickness measurements by Cirrus SD-OCT.

A possible strategy for implanting blue‐blocking intraocular lenses

Editor, Age-related macular degeneration (AMD) is said to be associated with sunlight exposure. This is supported by some epidemiological studies but not others. Epidemiological studies have also shown AMD progression following cataract surgery (Cuthbertson et al. 2009). Lipofuscin is considered a biomarker for cellular ageing and oxidative damage with one fluorophore A2E found in the retinal pigment epithelium (RPE) with peak sensitivity of short wavelength. It is thought to be an important mediator of AMD progression generating reactive oxygen species on photoexcitation and being phototoxic to RPE cells in culture (Algvere et al. 2006). Short wavelength light is absorbed by the ageing crystalline lens and this protective effect is lost following cataract surgery, likely resulting in cellular damage as a result (Algvere et al. 2006). Experimental studies showing the protective nature of a yellow intraocular lens (IOL) against radiation damage between 400 and 500 nm and the peak blue-light hazard of wavelengths at 435–440 nm (ICNIRP 1997) support this hypothesis (Cuthbertson et al. 2009). However the data is experimental and with conflicting evidence from epidemiological studies, the role of sunlight exposure in AMD remains inconclusive. In the 1980s, patients undergoing phacoemulsification surgery were given protection against radiation of wavelengths below 400 nm with clear UVR-blocking IOLs but not the blue-light hazard. Considering the experimental (Ham et al. 1976) and the epidemiological evidence that blue light induces damage in the retina, it is rational to implant a yellow IOL following phacoemulsification surgery, in patients at risk of AMD. However, early theoretical reports suggest yellow IOLs may have an effect on scotopic vision, reducing visual performance and contrast sensitivity when compared to a clear IOL due to blue light absorption. On the other hand, filtering out blue light improves the contrast on the retina in the sense that Rayleigh scattering in the vitreous is inversely proportional to the forth power of the wavelength. With foveal scotopic vision decreasing with age, the loss of blue light in the image caused by yellow IOLs may have an impact on night activities such as walking down stairs. Theoretical comparison between yellow IOLs and a middle aged crystalline lens indicated that the loss of blue light in the image may cause reduced scotopic sensitivity but this may not be clinically significant for scotopic vision and clinical trials with blue blocking IOLs have demonstrated no impact on contrast sensitivity (Cuthbertson et al. 2009). Blue light is said to have a role in the regulation of circadian rhythms which could affect sleep and lead to depression, although it is unclear how clinically relevant this is. Therefore, using clear IOLs with UV filters is also recommended over yellow IOLs further complicating the choice in IOL selection. Ideally, an IOL should have no effect on scotopic sensitivity and circadian rhythm with maximal protective effective against short wavelength phototoxicity. However, each of these scenarios has different peak wavelengths and therefore IOL selection will be a balance of these functions. Thus, clinical trials were not able to demonstrate a negative impact of blue blocking IOLs (Cuthbertson et al. 2009). However, if concern exists one option is to implant a clear IOL in one eye and a yellow IOL in the fellow eye. In a patient with bilateral asymmetrical AMD, we recommend that consideration should be given to implanting the yellow IOL in the eye with less severe disease to minimize AMD progression. The literature reports that most patients do not notice a problem with colour vision having a clear IOL in one eye and a yellow one in the other (Marshall et al. 2005; Algvere et al. 2006). There is only one case report of a patient who required explantation of the yellow IOL due to colour perception problems (Shah & Miller 2005). We anticipate this strategy will help minimize AMD progression and while preserving scotopic vision for patients undergoing cataract surgery if scotopic vision is an issue.

The Effect of Yellow Tinted Intraocular Lenses on the Result of Frequency Doubling Perimetry after Cataract Surgery

PurposeTo investigate the effect of yellow tinted intraocular lenses (IOLs), implanted in the bag after phacoemulsification, on the result of frequency doubling technique (FDT) perimetry.MethodsFor 68 eyes of 52 patients, an IOL was implanted in the bag after phacoemulsification. The patients were categorized into three groups according to the type of implanted IOLs used. IOLs were selected randomly among two types of yellow IOLs (Acrysof SN60WF IOL, Hoya YA60BBR IOL) and a clear IOL was used as a control. A FDT Humphrey matrix was performed 2 months after the surgery. The mean deviation (MD) and pattern standard deviation (PSD) among these three groups was analyzed using Mann-Whitney U-test.ResultsTwo months after the procedure, there was no significant difference between each of the three groups: the clear IOL and Hoya YA60BBR IOL (MD, p = 0.21; PSD, p = 0.27), the clear IOL and Alcon SN60WF IOL (MD, p = 0.11; PSD, p = 0.22), and the Hoya YA60BBR IOL and Alcon SN60WF IOL (MD, p = 0.33; PSD, p = 0.56).ConclusionsWhen interpreting the result of the FDT after cataract surgery, the color and type of IOLs used should not be considered.