Clear Intraocular Lens Research Articles

Comparison of color perception after tinted blue light–filtering and clear ultraviolet-filtering intraocular lens implantation

To compare color perception after implantation of clear and yellow-tinted intraocular lenses (IOLs). Dr. Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India. Comparative case series. This study evaluated eyes that had implantation of an Acrysof IQ SN60WF yellow-tinted IOL or an Acrysof SA60AT clear IOL. All eyes were evaluated postoperatively at 1 month and 3 months. The uncorrected distance visual acuity, intraocular pressure, and color vision (Ishihara pseudoisochromatic test, Edridge-Green lantern test, Heidelberg anomaloscope, and Farnsworth-Munsell (FM) 100-hue test) were evaluated. Both IOL groups comprised 50 eyes. There were no significant differences between the 2 groups in color vision on any of the 4 tests (P≥.05). Plotting the error scores on the polarity graph of the FM 100-hue test showed that eyes with a yellow-tinted IOL did not have a specific axis of confusion. There was no difference in color perception between the 2 IOLs irrespective of the color vision test used.

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.

Macular Pigment Changes in Pseudophakic Eyes Quantified with Resonance Raman Spectroscopy

We examined changes in macular pigment optical density (MPOD) levels after cataract surgery and compared the MPOD between eyes with clear intraocular lenses (IOLs) and yellow-tinted IOLs. Prospective, comparative case series. The MPOD levels were measured in 480 eyes of 337 patients after cataract surgery. Among them, the data from 259 eyes (clear IOL group, 121 eyes; yellow-tinted IOL group, 138 eyes) of 259 Japanese patients were selected for statistical analyses on the basis of the inclusion criteria: a postoperative visual acuity (VA) of ≥0.8 and no fundus diseases. Only 1 eye of each patient was enrolled. Patients provided informed consent to participate in this study on the basis of the approval of the institutional review board before surgery. The patients selected the type of IOL to be implanted. The MPOD levels were measured using resonance Raman spectroscopy on day 1 (baseline value); months 1, 3, and 6; and years 1 and 2 postoperatively. The difference in MPOD levels between the IOL groups was analyzed by unpaired t tests. The following parameters were analyzed by multiple regression analysis: age, gender, body mass index (BMI), smoking history, glaucoma, diabetes, preoperative VA, preoperative refractive error, and IOL power and type. We found no significant differences in the baseline characteristics between the 2 groups. Until 6 months postoperatively, the MPOD levels did not differ significantly between the groups. However, from 1 year onward, the levels were significantly higher in the yellow-tinted IOL group compared with the clear IOL group. By multiple regression analysis, 1 day postoperatively, older age and diabetes were correlated with lower MPOD levels; 1 year postoperatively and thereafter, however, lower MPOD levels were correlated with clear IOLs. Cataract surgery with clear IOLs induced a greater decrease in macular pigment levels compared with yellow-tinted IOLs during a longer follow-up period. These findings agreed with observations that excessive light exposure is associated inversely with MPOD, because clear IOLs transmit higher intensities of blue light than yellow-tinted IOLs.

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.

Comparison of photochromic, yellow, and clear intraocular lenses in human eyes under photopic and mesopic lighting conditions

To evaluate the results of the first blue light-filtering photochromic intraocular lens (IOL) and compare them with those of a regular yellow blue light-filtering IOL and a clear ultraviolet-filtering IOL in human eyes under various lighting conditions. Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University; Beijing Ophthalmology & Visual Sciences Key Laboratory, Beijing, China. Prospective comparative clinical study. This study evaluated eyes that had implantation of 1 of the following 3 IOLs: photochromic Aurium Matrix acrylic, model 400; yellow AF-1 (UY); or clear MC611MI. All eyes were followed for 3 months. The uncorrected (UDVA) and corrected (CDVA) distance visual acuities, contrast vision (lighting 400 lux, 30 lux, 5 lux), contrast sensitivity, color vision (Farnsworth-Munsell 100-hue test under 400 lux, 30 lux), and patient questionnaire responses were evaluated. The photochromic IOL group comprised 39 eyes; the yellow IOL group, 41 eyes; and the clear IOL group, 38 eyes. There were no significant differences between the 3 IOLs in UDVA, CDVA, contrast sensitivity, or questionnaire responses. The photochromic group had significantly better color vision than the yellow IOL group at 30 lux and better contrast vision at 5% contrast (P < .05); however, there were no significant differences between the photochromic IOL group and the clear IOL group (P > .05). The photochromic blue light-filtering IOL performed as well as the yellow and clear IOLs under photopic conditions. Under mesopic conditions, the yellow IOL gave poor color vision and contrast sensitivity.

Comparison of visual performance with blue light–filtering and ultraviolet light–filtering intraocular lenses

To compare the contrast sensitivity, glare, color perception, and visual acuity at different light intensities with yellow-tinted and clear intraocular lenses (IOLs) by different manufacturers. Ludwig Boltzmann Institute of Retinology and Biomicroscopic Laser-Surgery, Department of Ophthalmology, Rudolf Foundation Clinic, Vienna, Austria. Comparative case series. Eyes were randomized to 1 of the following IOLs: AF-1 (UY) (yellow tinted), AcrySof SN60AT (yellow tinted), AF-1 (UV) (clear), or AcrySof SA60AT (clear). One week and 2 months postoperatively, monocular contrast sensitivity function and color discrimination were tested and the corrected distance and near visual acuities were evaluated. All tests were performed under different light intensities (10 to 1000 lux). Of the 80 patients enrolled, 76 completed the study; there were 37 eyes in the yellow-tinted IOL group and 39 in the clear IOL group. There were no significant differences between yellow-tinted IOLs and clear IOLs except in color vision under mesopic conditions (10 lux). Patients with a yellow-tinted IOL made significantly more mistakes in the blue-light spectrum than patients with clear IOLs (P = .00015). There was no significant difference under photopic conditions (1000 lux). The yellow-tinted IOLs were equivalent to the clear IOLs in postoperative contrast sensitivity, visual acuity, and color perception under photopic conditions. Patients with yellow-tinted IOLs made statistically significantly more mistakes in the blue range under dim light than patients with clear IOLs.

The effect on visual function of Hydroview intraocular lens opacification: a cross-sectional study

Hydroview intraocular lenses (IOLs) have been associated with symptomatic opacification of the optic necessitating IOL exchange. Glare and misty vision have been noted as common presenting symptoms. This study's purpose was to investigate the impact of IOL opacification on objective measurements of visual function, including glare, and on vision-related quality of life. All patients who underwent Hydroview IOL implantation at Bristol Eye Hospital between December 2000 and the end of February 2001 were invited for assessment along with patients found to have Hydroview IOL opacification in routine ophthalmic clinics. Glare, visual acuity, contrast sensitivity, visual field, and colour vision were assessed. Vision-related quality of life and subject's symptoms were determined by questionnaire. IOL opacification was assessed by slit lamp bio-microscopy and anterior segment photography. Data from 129 patients were analysed. Fifty subjects had opacified IOLs and 79 clear IOLs. Subjects with opacified IOLs showed dramatically higher levels of glare (adjusted mean difference of 0.63 log units 95% CI, 0.45-0.82; P<0.001) with only mildly reduced visual acuity (adjusted mean difference of 0.09 logMAR units 95% CI, 0.03-0.15; P=0.002). Opacification was associated with poorer contrast sensitivity (P<0.001), visual field (P<0.001), and with lower vision-related quality of life (P<0.001). This study highlights the significant impact IOL opacification has on visual performance and experience, in particular glare and consequent impact on quality of life. The study shows that to quantify accurately the effect of IOL opacification on vision glare must be assessed.

Influence of a yellow-tinted intraocular lens on laser beam transmittance

To compare the transmittance of laser beams that are used for photocoagulation through a yellow-tinted intraocular lens (IOL) and a clear IOL. The transmittance of laser beams of different wavelengths (488 + 514, 514, 521, 568 and 647 nm) through yellow-tinted and clear IOLs of varying dioptric powers [+10, +20 and +30 dioptres (D)] was measured using a laser power meter. The transmittance ratio was defined as the ratio of the transmittance thorough a tinted IOL to that through a clear IOL, assuming that the transmittance value of the latter is 1; this ratio was calculated for each IOL and each wavelength of the laser beam. There were no apparent differences in the transmittance values between the tinted and clear IOLs when the 521, 568 and 647 nm wavelengths were used. In contrast, the transmittance ratio decreased for the tinted IOL when the short wavelengths - 488 + 514 and 514 nm - were used, especially when an IOL of a higher dioptric power was used. This ratio was found to be 91.9% for a +10 D, 86.7% for a +20 D and 82.2% for a +30 D lens when a 488 + 514 nm wavelength beam was used. When treating patients using photocoagulation, we must bear in mind the decreased transmittance ratio of short-wavelength laser beams when passed through tinted IOLs and increase the setting power of the beam accordingly.

Clinical research of high myopia corrected by clear lens extraction and intraocular lens implantation

目的 探讨透明晶状体超声乳化吸出联合人工晶状体植入术治疗高度近视的临床治疗效果.方法 对21例(37眼)高度近视行透明晶状体超声乳化联合人工晶状体植入术,观察术中、术后并发症以及术后视力改善情况,术后随访时间6～18月,平均12月.结果 术后裸眼视力低于0.2者1眼,0.2～0.5者3眼,0.5～0.9者32眼,≥1.0者1眼,矫正视力0.2～0.5者2眼,0.5～0.9者28眼,≥1.0者7眼,较术前均有显著提高.术后4眼出现后囊轻度浑浊,未见黄斑水肿和视网膜脱离等并发症.结论 通过仔细的术前检查,并掌握娴熟的手术技巧,透明晶状体超声乳化联合人工晶状体植入术能够作为治疗高度近视安全、有效的方法。

The Effect of the AcrySof Natural Lens on Glare Disability and Photostress

To investigate whether implanting "blue-filtering" yellow intraocular lenses (IOL) could provide a visual benefit in terms of glare disability and photostress recovery. A case-control study. Researchers masked to group assignments tested 58 subjects: 17 with yellow IOLs (AcrySof Natural; SN60WF; Alcon Laboratories Inc, Fort Worth, Texas, USA), 20 with clear IOLs, and 21 phakic controls. Photostress recovery and visual acuity under veiling glare conditions were assessed in a Maxwellian view optical system. Photostress recovery was assessed by measuring the time required to detect a grating stimulus (1 degree diameter) after a 5-second exposure to an intense circular disk (1 degree diameter) of broad-band xenon light. For the veiling glare experiment, subjects fixated on the grating stimulus, and the intensity of a broad-band xenon annulus (the glare source, 10 degrees inner, 12 degrees outer diameter) was adjusted until the grating stimulus was no longer seen. Subjects with AcrySof Natural (P < .0001) and clear IOLs (P < .035) could withstand significantly more light than the phakic controls. Subjects with the AcrySof Natural lens could withstand significantly more light (P < .02) than subjects with clear IOLs. Photostress recovery was significantly longer for subjects with clear IOLs vs phakic controls (P < .01), but the AcrySof Natural lens was not different from phakic controls (P < .09). Photostress recovery was similar between subjects with clear or AcrySof Natural lens (P < .32). The AcrySof Natural lens is related to reduced glare disability relative to a clear IOL or phakic controls.

Intraindividual comparison of color contrast sensitivity in patients with clear and blue-light-filtering intraocular lenses

To evaluate the effect of blue-light-filtering intraocular lenses (IOLs) with a yellow chromophore on color contrast sensitivity by intraindividual comparison with an identically designed IOL without a blue-light filter. Medical University of Vienna, Department of Ophthalmology, Vienna, Austria. Randomized implantation of an AF-1 (UV) IOL (Hoya) in 1 eye and an AF-1 (UY) IOL (Hoya) in the contralateral eye was performed after phacoemulsification and primary posterior curvilinear capsulorhexis. Three months postoperatively, the best distance-corrected visual acuity was evaluated. Before color contrast sensitivity testing, a heterochromatic flicker test was performed in both eyes to avoid error in brightness matching. Central and peripheral tritan color contrast sensitivities were evaluated using the Moorfields Vision System (CH Electronics). Visual acuity did not differ significantly between the 2 IOL groups (P>.05). The central color contrast sensitivity threshold also did not differ significantly between eyes with a clear IOL and eyes with a yellow IOL at any tested spatial frequency. The peripheral color contrast sensitivity test showed slightly higher color contrast sensitivity thresholds in eyes with a yellow IOL, although the differences were not statistically significant. Two patients independently reported subjective changes in color perception in the eye with the yellow IOL. In this intraindividual comparison, the implantation of a blue-light-filtering IOL did not lead to a clinically significant change in color contrast sensitivity.

Blue Light–Filter Intraocular Lenses in Vitrectomy Combined with Cataract Surgery: Results of a Randomized Controlled Clinical Trial

To evaluate the effect of the blue light-filter intraocular lenses (IOLs) in vitrectomy combined with cataract surgery, focusing on the surgeon's ability to perform specific vitreoretinal procedures and on the patients' outcome. Randomized clinical trial. Sixty patients, recruited from our outpatient department, were assigned randomly to receive an ultraviolet-filter IOL (clear IOL group) or a blue light-filter IOL (yellow IOL group) combined with a vitreoretinal procedure. Main outcome measures were intraoperative conditions for the surgeon and the functional outcome. Second outcome measures were complication rates and vitreoretinal diagnoses. The questionnaire responses showed that the blue light-filter IOLs did not represent an impediment to vitreoretinal surgery (P>.05). No intraoperative complications were encountered in either group. Patients in both IOL groups showed comparable functional results with respect to visual acuity, contrast sensitivity, color vision, and glare effect (P>.05). The functional outcome was influenced significantly by the vitreoretinal diagnosis (P<.01). With the possible advantage of macular protection and no intraoperative or functional disadvantage, the routine use of the blue light-filter IOL in combined surgery can be recommended.

Luminance contrast with clear and yellow-tinted intraocular lenses

To determine whether yellow-tinted intraocular lenses (IOLs) negatively affect luminance contrast in postoperative cataract patients. Department of Ophthalmology, Sir Mortimer B. Davis Jewish General Hospital, McGill University, Montreal, Quebec, Canada. Luminance contrast was measured using the minimum-motion technique. The stimulus consisted of blue and red sinusoidal gratings differing in luminance. Patients had implantation of a clear or yellow-tinted IOL and were tested monocularly 2 to 9 weeks after cataract surgery. No patient had concomitant ocular diseases or congenital color defects, assessed by their ophthalmologist, or flicker-sensitive epilepsy. All patients had a visual acuity of 20/40 or better a mean of 4 weeks+/-2 (SD) postoperatively. Patients ranged in age from 55 to 89 years. An independent-samples Student t test showed that patients with a yellow-tinted IOL had significantly lower luminance contrast values than patients with a clear IOL (P<.05). The results suggest that yellow-tinted IOLs affect the perception of luminance under photopic conditions. More blue light was required to make luminance judgments with a yellow-tinted IOL than with a clear IOL. Further study of the functional impact of luminance reduction by yellow-tinted IOLs is warranted.

Refractive Surgery in Children: Is it Ready for Prime Time?

IntroductionPotential indications for excimer laser procedures in children include accommodative esotropia, bilateral high ametropia, and severe anisometropia. Treatment of these conditions has traditionally included spectacle or contact lens use. This treatment, however, is often ineffective in children with severe anisometropia or bilateral ametropia, especially those with neuropsychological disorders. Refractive surgery may be a viable treatment option for these conditions.MethodsThe visual and refractive results from our studies on photorefractive keratectomy for pediatric anisometropic amblyopia are discussed. Also, I will present a review of the world literature on excimer laser procedures for accommodative esotropia, pediatric high anisometropia, and pediatric bilateral high ametropia.ResultsIn our study, at 36 months follow-up, 7 of 9 patients who were able to perform psychophysical acuity testing preoperatively had improvement of two or more lines of uncorrected visual acuity and 6 of 9 had improvement of two or more lines of best corrected visual acuity. Fifty percent of the myopic patients and 100% of the hyperopic patients were within 2 D of refractive target at the 36-month follow-up visit. Refractive error stability has been good and corneal haze has been minimal.ConclusionsRefractive surgery in children to reduce amblyopiogenic levels of refractive error is proving to be relatively stable. Best corrected and uncorrected visual acuity has also been shown to improve following the excimer laser procedures. Refractive surgery also appears to be effective for pure accommodative esotropia. Randomized clinical trials are needed to fully establish safety and efficacy. Other refractive procedures, such as clear lens extraction and phakic intraocular lenses, may also prove to be valid treatment options for these conditions in the future.

Changes in Corneal Astigmatism and High Order Aberrations After Clear Corneal Tunnel Phacoemulsification Guided by Corneal Topography

To study changes in corneal astigmatism and high order aberrations after clear corneal tunnel phacoemulsification guided by corneal topography. All patients were randomly assigned to the test group or the control group. Corneal topography-guided clear corneal tunnel phacoemulsification followed by intraocular lens (IOL) implantation was performed on 22 eyes of 16 patients in the test group and conventional temporal corneal tunnel phacoemulsification and IOL implantation were performed on 22 eyes of 21 patients in the control group. The corneal astigmatism and high order aberrations were measured using the NIDEK OPD-Scan aberrometer and topographer preoperatively and up to 3 months after surgery. The corneal astigmatism and sixth order root-mean-square (RMS) for corneal coma, trefoil, spherical, secondary coma, and secondary spherical aberrations at 4-mm pupil diameters were compared. Fifteen (69%) eyes in the test group and 8 (36%) eyes in the control group achieved > or =20/25 uncorrected visual acuity 3 months after surgery, which was statistically significant (P<.05). The best spectacle-corrected visual acuity was > or =20/20 in 14 (63%) eyes in the test group and 10 (45%) eyes in the control group. The mean surgically induced astigmatism in the test group was 0.58+/-0.39 diopters (D) compared with 0.73+/-0.41 D in the control group. The change in corneal astigmatism from preoperative to 3 months after surgery was -0.17+/-0.32 D for the test group and 0.10+/-0.41 D for the control group, which was statistically significant (P<.05). The RMS value of trefoil aberrations increased, and all other aberrations decreased at 3 months after surgery in the test group. The RMS values of all corneal high order aberrations increased in the control group, with the increase in trefoil being statistically significant. The comparison of surgically induced high order aberrations between the two groups showed that corneal coma, trefoil, and secondary coma were significantly different. Clear corneal tunnel phacoemulsification and IOL implantation guided by corneal topography can yield better visual acuity by reducing the pre-existing astigmatism and inducing less corneal aberrations than conventional temporal corneal tunnel phacoemulsification.

Protective effects of soft acrylic yellow filter against blue light-induced retinal damage in rats

Recently, a yellow intraocular lens (IOL) was developed for the purpose of reducing potential blue light-induced retinal damage after cataract surgery. However, the effect of yellow filters on retinal protection remains to be clarified. To test the protective effects of yellow filters on blue light-induced retinal damage, a yellow and a clear soft acrylic filter were attached to the right and left eyes, respectively, of albino rats and exposed to 4.5 k lux blue fluorescent lights with peak wavelength at 420 nm (ranging 380–500 nm; short blue) or 446 nm (ranging 400–540 nm; long blue) for 6 h. To assess retinal damage, the electroretinogram (ERG) was recorded at 7 days, outer nuclear layer (ONL) thickness and area were measured at 7 days, apoptosis was analyzed by TUNEL staining at 24 h, and the level of lipid peroxidation in retinas was assessed by Western dot blots using specific antibodies against 4-hydroxynonenal (4-HNE)- and carboxyethylpyrrole (CEP)-modified proteins immediately after light exposure. After short blue light exposure, a- and b-wave ERG amplitudes and the ONL thickness at 1–2.5 mm inferior and 0.5–2.5 mm superior to optic nerve head (ONH) were significantly reduced. TUNEL staining in the ONL at 0–2 mm inferior and 1–2 mm superior to the ONH, and retinal levels of 4-HNE- and CEP-modified proteins were significantly increased in the clear filter-covered eyes compared to yellow filter-covered eyes. After long blue light exposure, the only difference seen was a greater ONL thickness at 1.5 mm superior to the ONH in yellow filter-covered eye. Transmission of light through the yellow filter was 58% for short blue and 89% for long blue compared to the clear filter. The ONL area was not different between clear filter-covered and -uncovered eyes after exposure to short or long blue light. Given the results, yellow IOL material protects the retina against acute shorter wavelength blue light exposure more effectively than the clear IOL material.

Hydrophilic acrylic intraocular lens exchange: Five-year experience

To evaluate clinical outcomes of opacified SC60B-0UV intraocular lens (IOL) (MDR, Inc.) and clear SC60B-0UV IOL exchange. Department of Ophthalmology, Queen's Hospital, Burton-on-Trent, United Kingdom. In a prospective audit, 149 patients with 152 SC60B-0UV hydrophilic acrylic IOLs were monitored over 5 years. Perioperative complications were evaluated. The best spectacle-corrected visual acuity, subjective quality of vision, and VF-14 scores were compared preoperatively and postoperatively. Ninety-eight IOLs developed opacification; 52 IOLs were exchanged between February 1999 and October 2004. The lens exchange procedure was uneventful in 39 eyes (75%). Perioperative complications included zonular dehiscence and posterior capsule rupture in 12 eyes (23.1%), total capsule-IOL extraction in 4 eyes (7.7%), iridodialysis in 3 eyes (5.8%), hyphema in 2 eyes (3.8%), and retained haptics in 5 eyes (9.6%). The mean logMAR visual acuity and mean VF-14 scores improved significantly after IOL exchange (P < .01). Forty-seven patients (90.4%) reported improvement in the subjective quality of vision after IOL exchange. However, after the exchange, visual acuity worsened in 5 patients (9.6%) and subjective quality of vision worsened in 3 patients (5.8%); the VF-14 scores decreased in 5 (14.7%) of the 34 patients tested. Visual function and quality of life were better after IOL exchange. However, poor outcomes in some patients mandate an extensive informed consent procedure for clear IOL exchange.

Implanting a Clear Intraocular Lens in One Eye and a Yellow Lens in the Other Eye: A Case Series

To describe the color vision disturbance reported by patients in whom a clear intraocular lens (IOL) was implanted in one eye and a yellow-tinted (blue-light-absorbing) IOL in the other eye. Retrospective interventional case series. Data recorded included demographic information, dates of surgery, IOL model and power (manufacturer is the same for all lenses), best-corrected visual acuity, and subjective visual complaints. Four of five patients had no spontaneous color vision complaints. When these patients were informed of the unintended mismatch, all remarked that they could perceive a color vision difference, but that it was not bothersome. One of the five patients reported "beige" vision. None of the patients wanted an IOL exchange. Many patients can tolerate the color vision imbalance that results when a clear IOL is implanted in one eye and a yellow-tinted IOL is implanted in the other eye.

Age‐related maculopathy and the impact of blue light hazard

The pathogenesis of age-related maculopathy (ARM), the most common cause of visual loss after the age of 60 years, is indeed a complicated scenario that involves a variety of hereditary and environmental factors. The pathological cellular and molecular events underlying retinal photochemical light damage, including photoreceptor apoptosis, have been analysed in experimental animal models. Studies of age-related alterations of the retina and photoreceptors, the accumulation of lipofuscin in retinal pigment epithelium (RPE) cells, and the formation of drusen have greatly contributed to our knowledge. A new concept of an inflammatory response to drusen has emerged, suggesting immunogenic and systemic reactions in Bruch's membrane and the subretinal space. Oxidative stress and free radical damage also impact on the photoreceptors and RPE cells in the ageing eye. Based on the photoelectric effect, a fundamental concept in quantum physics, the consequences of high-energy irradiation have been analysed in animal models and cell culture. Short-wavelength radiation (rhodopsin spectrum), and the blue light hazard (excitation peak 440 nm), have been shown to have a major impact on photoreceptor and RPE function, inducing photochemical damage and apoptotic cell death. Following cataract surgery, there is a dramatic change in ocular transmittance. In aphakic or pseudophakic eyes (with clear intraocular lenses), high-energy (blue) and ultraviolet-A radiation strikes the retina. Epidemiological data indicate a significantly increased 5-year incidence of late ARM in non-phakic eyes compared with phakic eyes. In recent years, putative prophylactic measures against ARM have emerged. The implantation of 'yellow' intraocular lenses (IOLs) that absorb high-energy blue radiation is, from a theoretical point of view, the most rational approach, and, from a practical point of view, is easy to accomplish. With increasing age, RPE cells accumulate lipofuscin (chromophore A2E). It is noteworthy that the yellow IOL not only protects A2E-laden human RPE cells from blue light (peak 430 nm) damage, but also alleviates the detrimental effects of green (peak 550 nm) and white light. A prophylactic treatment using antioxidants is aimed at counteracting oxidative stress and free radical cellular damage. The Age-Related Eye Disease Study (AREDS), a randomized clinical trial, showed a significantly lower incidence of late ARM in a cohort of patients with drusen maculopathy treated with high doses of antioxidants than in a placebo group. In recent years, considerable progress in retinal research has been achieved, creating a platform for the search for new prophylactic and therapeutic measures to alleviate or prevent photoreceptor and RPE degeneration in ARM.

Comparison of Contrast Sensitivity and Color Discrimination After Clear and Yellow Intraocular Lens Implantation

Comparison of Contrast Sensitivity and Color Discrimination After Clear and Yellow Intraocular Lens Implantation