Intraindividual comparison of a blue-light filter on visual function: AF-1 (UY) versus AF-1 (UV) intraocular lens

Blue Light Filtration in Intraocular Lenses: Effects on Visual Function and Systemic Health

Blue light-filtering (BLF) intraocular lenses (IOLs) are designed to mimic the healthy natural adult crystalline lens. Studies that evaluated the relative merit of ultraviolet-only IOL design (ie, blocking wavelengths <400 nm) versus BLF IOL design (ie, filtering wavelengths ~400-475 nm in addition to blocking wavelengths <400 nm) on protection and function of the visual system suggest that neither design had a deleterious impact on visual acuity or contrast sensitivity. A BLF design may reduce some aspects of glare, such as veiling and photostress. BLF has been shown in many contexts to improve visual performance under conditions that are stressed by blue light, such as distance vision impaired by short-wave dominant haze. Furthermore, some data (mostly inferential) support the notion that BLF IOLs reduce actinic stress. Biomimetic BLF IOLs represent a conservative approach to IOL design that provides no harm for visual acuity, contrast sensitivity, or color vision while improving vision under certain circumstances (eg, glare).

Clinical Evaluation of a Modified Light Transmission Short-Wavelength Filtering Intraocular Lens Compared to a Colorless Control

INTRODUCTION

The aim of this study was to evaluate the safety and efficacy of a violet-light filtering intraocular lens (IOL) compared to a colorless IOL control.

METHODS

This was a prospective, bilateral, randomized, comparative, patient/evaluator-masked multi-center clinical trial at 12 sites in the USA. Patients underwent standard small-incision phacoemulsification cataract extraction. Visual acuity, contrast sensitivity, and color vision were tested 12 months postoperatively. Patient satisfaction and vision-related quality of life were evaluated based on directed patient responses obtained from a binocular subjective questionnaire.

RESULTS

A total of 250 subjects were bilaterally implanted with the violet-light filtering TECNIS monofocal ZV9003 (n = 126) and colorless TECNIS monofocal ZA9003 (n = 124). Mean uncorrected distance visual acuity (UDVA) was 0.123 LogMAR for ZV9003 and 0.116 LogMAR for the ZA9003 group. Mean corrected distance visual acuity (CDVA) was 0.00 LogMAR for both groups. No significant difference was found between the groups for 22/25 questionnaire categories, including color perception. A significant difference was found in favor of the ZV9003 group for day driving, night driving, and frustration with vision. Contrast sensitivity mean difference was < 0.05 log units across all lighting conditions and spatial frequencies.

CONCLUSION

No difference was found between groups for visual acuity, contrast sensitivity, color testing, and adverse events as well as with the majority of optical/visual symptoms. A statistical difference was noted in driving and frustration with eyesight that may be related to benefits of using a violet-light filtering chromophore. Overall, the violet-light filtering ZV9003 showed excellent visual acuity and contrast sensitivity results with a low incidence of optical/visual symptoms.

Unexpected vision performance with photochromic contact lenses in normal and low light conditions: An analysis of two randomized trials

PURPOSE

Evaluate the performance of a photochromic contact lens in various lighting conditions throughout the day, including those indoor and outdoor environments where the photochromic contact lens is in a less active or inactive state.

METHODS

Data from two clinical trials of a photochromic contact lens were analyzed to evaluate its performance in various light environments. Both studies involved a photochromic test lens (ACUVUE® OASYS with Transitions™ Light Intelligent Technology™) and a similar non-photochromic control lens (ACUVUE® OASYS 2-week with HYDRACLEAR® PLUS). The studies were both multi-visit, multi-site, 2-treatment by 3-period randomized crossover (i.e., Test/Control/Control or Control/Test/Test) dispensing studies, with follow-up visits after each 2-week dispensing period.

RESULTS

A total of 250 subjects were dispensed lenses across both studies, of which 237 total subjects completed. In situations where exposure to an activating light source is common (e.g., outdoors), the Test lens was preferred nearly 6:1 over the control lens. In situations where exposure to an activating light source is less common - indoors, driving at night, using digital devices -, the Test lens was still preferred over the control lens by margins of 4:1, nearly 4:1, and over 3:1 respectively. The Test lens was superior with respect to quality of vision, ability to see comfortably, clarity of vision, reduction of squinting while using computers and reduction of bright light while driving at night.

CONCLUSION

The photochromic test contact lens was rated superior to a non-photochromic control lens in environmental situations where the lens is in a less active or inactive state.

Effect of Blue Light-Filtering Intraocular Lenses on Age-Related Macular Degeneration: A Nationwide Cohort Study With 10-Year Follow-up

PURPOSE

To determine the incidence rate of age-related macular degeneration (AMD) after cataract surgery and compare the relative incidence of AMD in pseudophakes with blue light-filtering intraocular lenses (BF-IOLs) and non-BF-IOLs.

DESIGN

A nationwide cohort study conducted using the Taiwan National Health Insurance Research Database.

METHODS

We enrolled 186,591 patients who underwent cataract surgery in both eyes between 2008 and 2013 and monitored them from the index date (the date of first cataract surgery) until AMD, death, loss to follow-up, or December 31, 2017, whichever occurred first. Propensity score matching (PSM) was used to balance the baseline characteristics between the BF-IOL and non-BF-IOL groups.

RESULTS

BF-IOLs were implanted in 21,126 patients (11.3%) and non-BF-IOLs were implanted in 165,465 patients (88.7%). Patients in the BF-IOL group tended to be younger, with fewer men, different cataract surgery years, higher income, more nonmanual workers, more patients from urban and suburban areas, and fewer chronic diseases compared with the non-BF-IOL group. With a mean follow-up period of 6.1 years (range, 1-10 years) after cataract surgery, 12,533 and 1655 patients developed non-exudative AMD and exudative AMD, respectively. The incidence rate of non-exudative AMD and exudative AMD (per 1000 person-years) was 9.95 and 1.22 for the BF-IOL group and 11.13 and 1.44 for the non-BF-IOL group, respectively. After PSM, no statistical difference in the incidence rate of nonexudative AMD (hazards ratio, 0.95; 95% CI, 0.88-1.03) and exudative AMD (hazard ratio, 0.96; 95% CI, 0.77-1.18) was observed between the BF-IOL and non-BF-IOL groups.

CONCLUSIONS

In Taiwan, the incidence rate of AMD after cataract surgery was 11.59 per 1000 person-years. The use of a BF-IOL for up to 10 years had no apparent advantage over a non-BF-IOL in the incidence of AMD.

Effect of Blue Light Filtering Intraocular Lenses on Visual Perception

Background and Objectives: This retrospective consecutive case control study compares best-corrected visual acuity (BCVA), mesopic contrast sensitivity (CS), color vision, and glare between a group of eyes with blue-light-filtering intraocular lenses and another with UV-light-filtering intraocular lenses. Materials and Methods: We used Early Treatment Diabetic Retinopathy Study charts to compare BCVA, Rabin charts for mesopic CS testing, Oculus HMC Anomaloscope MR to test for chromatic discrimination, and Oculus Mesotest II to measure scotopic CS with glare. For analysis, we used descriptive statistics and compared means with parametric and non-parametric tests. The level of significance was set as α = 0.05. Results: For the group with the blue-light-filtering intraocular lens, the average results were BCVA = 0.96 (SD ± 0.09), CS = 1.78 log (SD ± 0.12), chromatic discrimination results M = 63.91 (SD ± 11.88), R = 60.07 (SD ± 7.89). For mesopic CS with glare, the group achieved on average 2.54 (SD ± 1.50) points out of 4. For the group with the UV-light-filtering intraocular lens, the average results were BCVA = 0.93 (SD ± 0.14), CS = 1.79 log (SD ± 0.13), chromatic discrimination results M = 65.38 (SD ± 17.14), R = 60.79 (SD ± 10.39). For mesopic CS with glare, this group achieved an average of 2.79 (SD ± 1.53) points out of 4. Conclusion: No significant differences (p > 0.05) were found in any of the tested parameters between the analyzed groups. Slight shift in color vision was observed, although not statistically significant.

Uveal and capsular biocompatibility of a new hydrophobic acrylic microincision intraocular lens

PURPOSE

To evaluate uveal biocompatibility and capsular bag opacification of a new hydrophobic acrylic microincision intraocular lens (IOL) in comparison with a commercially available 1-piece hydrophobic acrylic IOL.

SETTING

John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, USA.

DESIGN

Experimental study.

METHODS

Eight New Zealand rabbits underwent bilateral phacoemulsification and implantation of the preloaded Nanex multiSert IOL in one eye and a commercially available preloaded lens (AcrySof IQ in UltraSert, model AU00T0) in the contralateral eye. A slitlamp examination was performed weekly for 4 weeks. The rabbits were then killed humanely and their globes enucleated. Capsular bag opacification was assessed from the Miyake-Apple view, and the eyes were subjected to histopathologic evaluation.

RESULTS

Postoperative inflammatory reactions were similar between the test and control eyes in the 8 New Zealand rabbits. The mean postmortem central posterior capsule opacification (PCO) was 0.93 ± 0.73 in the test group and 1.19 ± 0.53 in the control group. The mean postmortem peripheral PCO was 1.75 ± 0.92 in the test group and 2.06 ± 0.77 in the control group. Central and peripheral PCO scores were not statistically different between the test and control groups (P = .41 and P = .35, respectively, 2-tailed t test: paired 2-sample for means).

CONCLUSIONS

A new 1-piece hydrophobic acrylic microincision IOL incorporating an ultraviolet-ozone treatment on the posterior surface performed similarly to a commercially available 1-piece hydrophobic acrylic IOL in terms of uveal and capsular biocompatibility in the rabbit model. To our knowledge, this is the first hydrophobic acrylic microincision IOL to demonstrate similar PCO performance when compared with a conventional, commercially available IOL.

The Effect of Blue-blocking Lenses on Photostress Recovery Times

SIGNIFICANCE

The selective reduction in visible wavelengths transmitted through commercially available blue-blocking lenses (BBLs) is known to influence the appearance and contrast detection of objects, particularly at low light levels. This influence may impair the human retinal receptor response time to dynamic light changes during photostress events.

PURPOSE

This study aimed to assess whether BBLs selectively affect photostress recovery times (PSRTs) for chromatic and achromatic stimuli of different Weber contrasts that were viewed on a dark black background.

METHODS

Photostress recovery times were measured in 12 younger participants (18 to 39 years old) with no history of ocular disease or abnormal vision. Photostress recovery times were evaluated for four brands of BBLs, which were compared with a control lens. In these experiments, after exposure to an intense light source for 5 seconds, the time taken to recover vision and correctly identify a computer-generated letter stimulus viewed under low and high luminance levels was determined, which means perception is likely to be governed by mesopic and photopic conditions. Across conditions, the letter stimulus was achromatic and chromatic and could differ in luminance contrast.

RESULTS

Under photopic stimulus conditions, although reducing luminance contrast increased PSRTs, BBLs had no significant effect on PSRTs relative to control lens. However, under mesopic stimulus conditions, BBLs significantly affect PSRTs for both achromatic (F2.006,8.02 = 61.95, P < .0001) and chromatic stimuli (F3,16 =139.01, P < .0001), particularly for blue targets, which had considerably longer PSRTs (38.40 seconds). The brand of BBL was also shown to selectively affect PSRTs, with those with transmittance profiles that block the most blue light having longer PSRTs.

CONCLUSIONS

The present study suggests that, although the color and contrast of the target stimuli affected recovery times, the difference in recovery times between different types of BBLs was noticed only under low-light-level stimulus conditions.

Effect of blue-blocking lenses on colour contrast sensitivity

CLINICAL RELEVANCE

There is a significant unintended consequences of blue-blocking lenses on visual behaviour, particularly for the detection of colour. Optometrists need to be mindful of this when prescribing the appropriate blue-blocking lenses for individuals who work in environments in which blue light is prevalent.

BACKGROUND

The selective reduction in visible wavelengths transmitted through commercially available blue-blocking lenses is known to influence object appearance and luminance contrast, and also potentially object colour contrast. The present study investigated the effect of a number of commercially available blue-blocking lenses on colour contrast sensitivity in normal individuals under low and high contrast stimulus conditions.

METHODS

Five healthy participants (one man and four women), aged between 23 and 39-years, were recruited for this study. Crizal Prevencia (Essilor), Blue Guardian (Opticare), and Blu-OLP (GenOp) lenses were examined in this study in comparison to a control lens (clear lens without blue-filtering coating). In Experiment 1, colour contrast thresholds were measured using a visual search colour detection task in which the colour (CIE Lu'v' red, green, blue and yellow) of the target circle stimulus (randomly located in an annulus of achromatic circles) was systematically reduced using a staircase procedure. As blue-blocking lenses selectively block blue light, in Experiment 2, colour contrast thresholds were specifically quantified for a range of short wavelengths near the attenuation transmittance range of the blue-blocking lenses tested.

RESULTS

Experiments 1 and 2 showed that colour contrast was impaired only for blue colours, and this was most evident at low contrasts. Additionally, the blue-blocking lenses with lower transmittance profiles led to greater reductions in colour contrast sensitivity and shown to affect colour contrast thresholds.

CONCLUSION

Our results suggest that while reducing blue light potentially minimises the harmful effect of blue hazard light, blue-blocking lenses can unintentionally reduce colour contrast sensitivity, particularly at low light levels.

The Effect of Blue-Light Filtering Intraocular Lenses on the Development and Progression of Neovascular Age-Related Macular Degeneration

PURPOSE

To assess the effect of blue-light filtering (BLF) intraocular lenses (IOLs) on the prevention of neovascular age-related macular degeneration (nAMD) after cataract surgery.

DESIGN

Cohort study.

PARTICIPANTS

Patients who underwent uneventful cataract surgery between 2007 and 2018 at the Ophthalmology Unit of Kymenlaakso Central Hospital, Kotka, Finland.

METHODS

Subsequent nAMD rates were compared between patients who received BLF IOLs and those who received non-BLF IOLs. Kaplan-Meier and Cox regression analyses for the overall risk of nAMD developing were assessed. Best-corrected visual acuity (BCVA), foveal thickness, treatment interval, and total number of intravitreal injections were secondary outcomes. A separate analysis was performed on patients with pre-existing nAMD to assess the effect of BLF IOLs on nAMD progression. A single eye of each patient was included.

MAIN OUTCOME MEASURE

Neovascular age-related macular degeneration-free survival.

RESULTS

Included were 11 397 eyes of 11 397 patients with a mean age of 75.4 ± 8.3 years (62.5% women). The BLF IOL was used in 5425 eyes (47.6%), and the non-BLF IOL was used in 5972 eyes (52.4%). During follow-up (BLF IOL group, 55.2 ± 34.1 months; non-BLF IOL group, 50.5 ± 30.1 months; P < 0.001), 164 cases of new-onset nAMD were recorded (BLF group, n = 88; non-BLF group, n = 76). The nAMD-free survival was similar between the groups (P = 0.465, log-rank test). In a Cox regression analysis controlling for age, gender, and a documented diagnosis of macular degeneration, the use of a BLF IOL was not predictive of nAMD development (hazard ratio [HR], 1.075; 95% confidence interval [CI], 0.79-1.47; P = 0.652). In nAMD patients, secondary clinical outcomes at 1 year were comparable for BCVA (0.57 ± 0.4 logarithm of the minimum angle of resolution vs. 0.45 ± 0.4 logarithm of the minimum angle of resolution; P = 0.136), foveal thickness (285 ± 109 μm vs. 299 ± 103μm; P = 0.527), number of anti-vascular endothelial growth factor injections (6.5 ± 2.5 vs. 6.2 ± 2.7; P = 0.548), and treatment interval (7.5 ± 2.4 weeks vs. 8.1 ± 2.4 weeks; P = 0.271) for BLF and non-BLF IOLs, respectively. Similarly to patients in whom nAMD developed after the surgery, among patients with nAMD before surgery (BLF, n = 71; non-BLF, n = 74), the clinical outcomes again were comparable (all P > 0.05).

CONCLUSIONS

In a large cohort of patients who underwent cataract surgery, the use of a BLF IOL resulted in no apparent advantage over a non-BLF IOL in the incidence of nAMD or its progression, nor in clinical variables related to nAMD severity.

Intraocular cataract lens replacement and light exposure potentially impact procedural learning in older adults

Procedural learning declines with age and appropriately timed light exposure can improve cognitive performance in older individuals. Because cataract reduces light transmission and is associated with cognitive decline in older adults, we explored whether lens replacement (intraocular blue-blocking [BB] or UV-only blocking) in older patients with cataracts enhances the beneficial effects of light on procedural learning. Healthy older participants (n = 16) and older patients with post-cataract surgery (n = 13 with BB or UV lens replacement) underwent a randomized within-subject crossover laboratory design with three protocols. In each protocol, 3.5 hr dim-dark adaptation was followed by 2 hr evening blue-enriched (6,500K) or non-blue-enriched light exposure (3,000K or 2,500K), 30 min dim post-light, ~8 hr sleep and 2 hr morning dim light. Procedural learning was assessed by the alternating serial reaction time task (ASRT), as part of a larger test battery. Here, ASRT performance was indexed by type of trial (random or sequence) and sequence-specific (high or low probability) measures. During evening light exposure, we observed a significant effect of the interaction of "group" versus "light condition" on the type of trial (p = .04; p = .16; unadjusted and adjusted p-values, respectively) and sequence-specific learning (p = .04; p = .16; unadjusted and adjusted p-values, respectively), whereby patients with UV lens replacement performed better than patients with BB lens or non-cataract controls, during blue-enriched light exposure. Lens replacement in patients with cataracts may potentially be associated with beneficial effects of blue light on procedural learning. Thus, optimizing spectral lens transmission in patients with cataracts may help improve specific aspects of cognitive function, such as procedural learning.

Visual and refractive outcomes and glistenings occurrence after implantation of 2 hydrophobic acrylic aspheric monofocal IOLs

PURPOSE

To compare the Clareon IOL with the Tecnis PCB00 IOL in terms of visual performance, refractive outcomes, glistenings occurrence, and quality-of-life outcomes.

SETTING

Guy's and St Thomas' NHS Foundation Trust, London, United Kingdom.

DESIGN

Single-center, single-masked, prospective, randomized controlled trial.

METHODS

One hundred thirty-nine patients with bilateral cataracts were randomized to receive the Clareon (C IOL) or Tecnis (T IOL) IOL. Visual acuity, refraction, central corneal thickness (CCT), endothelial cell loss, contrast sensitivity, mesopic gap acuity, evaluation of glistenings, and rates of perioperative and postoperative complications were recorded. Quality-of-life outcomes were measured with the EuroQOL-5 dimensions questionnaire and the patient-reported outcome measures (PROMs) questionnaire. Optimized A-constants were available for the T IOL but not for the C IOL.

RESULTS

Seventy-one patients (140 eyes) received the C IOLs and 68 patients (134 eyes) received the T IOLs. Data were analyzed for the first implanted eye. At 12 months, mean uncorrected distance visual acuity (logarithm of the minimum angle of resolution) was 0.02 ± 0.10 and 0.01 ± 0.08 (mean ± SD; P = .49; 95% CI, -0.02 to 0.04) in the C IOL and T IOL groups, respectively. Corrected distance visual acuity was -0.02 ± 0.09 and -0.03 ± 0.06, respectively (P = .45; 95% CI, -0.02 to 0.04). The increase in CCT was 14 ± 19 and 16 ± 28 μm, respectively (P = .63; 95% CI, -10.16 to 6.16). Mean absolute refraction spherical equivalent error from target refraction was 0.41 ± 0.28 for the C IOL and 0.25 ± 0.2 for the T IOL groups (P = .002; 95% CI, 0.08 to 0.24). Glistenings were minimal (median grade 0), with no difference in grades between groups (P = .2). PROMs improved postoperatively and were similar in both groups.

CONCLUSIONS

There were no differences in visual outcomes between the Clareon IOL and Tecnis PCB00 IOL. Glistenings were rarely observed in either IOL with no difference in grades. There was no difference in perioperative or postoperative complications. Surgeon optimization of the A-constant for the Clareon IOL is recommended.

The Effects of Blue Light-Filtering Intraocular Lenses on the Protection and Function of the Visual System

Filtration of high-energy short-wave visible light (blue light) to improve vision and protect against damage has evolved both in aquatic animals and terrestrial species. In humans, pigments in the inner layer of the macula absorb wavelengths between 400 and 520 nm and function to improve visual performance. In patients who undergo cataract surgery, replacing cataractous lenses with artificial intraocular lenses (IOLs) that do not mimic normal healthy adult lenses could result in preventable negative visual effects, including glare disability. Blue light-filtering (BLF) IOLs were designed to filter short-wave light in addition to ultraviolet light and mimic the natural crystalline lens. Current studies indicate that BLF IOLs may provide protection from blue light-induced retinal damage and slow the development and progression of age-related macular degeneration. Additionally, BLF IOLs have been shown to improve chromatic contrast, reduce photostress recovery time, reduce glare disability and discomfort, and generally improve visual performance under glare conditions. Although a number of concerns have been raised about the relative risks versus the benefits of BLF IOLs, recent studies reported no adverse effects on visual function or contrast under photopic conditions, no long-term effects on color vision, and no detrimental effects on circadian rhythms with BLF IOLs. Based on the current understanding of the field, evidence suggests that BLF IOLs would be returning the eye to a more natural state compared with non-BLF lenses.

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

OBJECTIVES

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.

Blue-light filtering intraocular lenses (IOLs) for protecting macular health

BACKGROUND

An intraocular lens (IOL) is a synthetic lens that is surgically implanted within the eye following removal of the crystalline lens, during cataract surgery. While all modern IOLs attenuate the transmission of ultra-violet (UV) light, some IOLs, called blue-blocking or blue-light filtering IOLs, also reduce short-wavelength visible light transmission. The rationale for blue-light filtering IOLs derives primarily from cell culture and animal studies, which suggest that short-wavelength visible light can induce retinal photoxicity. Blue-light filtering IOLs have been suggested to impart retinal protection and potentially prevent the development and progression of age-related macular degeneration (AMD). We sought to investigate the evidence relating to these suggested benefits of blue-light filtering IOLs, and to consider any potential adverse effects.

OBJECTIVES

To assess the effects of blue-light filtering IOLs compared with non-blue-light filtering IOLs, with respect to providing protection to macular health and function.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (which contains the Cochrane Eyes and Vision Trials Register) (2017, Issue 9); Ovid MEDLINE; Ovid Embase; LILACS; the ISRCTN registry; ClinicalTrials.gov and the ICTRP. The date of the search was 25 October 2017.

SELECTION CRITERIA

We included randomised controlled trials (RCTs), involving adult participants undergoing cataract extraction, where a blue-light filtering IOL was compared with an equivalent non-blue-light filtering IOL.

DATA COLLECTION AND ANALYSIS

The prespecified primary outcome was the change in distance best-corrected visual acuity (BCVA), as a continuous outcome, between baseline and 12 months of follow-up. Prespecified secondary outcomes included postoperative contrast sensitivity, colour discrimination, macular pigment optical density (MPOD), proportion of eyes with a pathological finding at the macula (including, but not limited to the development or progression of AMD, or both), daytime alertness, reaction time and patient satisfaction. We evaluated findings related to ocular and systemic adverse effects.Two review authors independently screened abstracts and full-text articles, extracted data from eligible RCTs and judged the risk of bias using the Cochrane tool. We reached a consensus on any disagreements by discussion. Where appropriate, we pooled data relating to outcomes and used random-effects or fixed-effect models for the meta-analyses. We summarised the overall certainty of the evidence using GRADE.

MAIN RESULTS

We included 51 RCTs from 17 different countries, although most studies either did not report relevant outcomes, or provided data in a format that could not be extracted. Together, the included studies considered the outcomes of IOL implantation in over 5000 eyes. The number of participants ranged from 13 to 300, and the follow-up period ranged from one month to five years. Only two of the studies had a trial registry record and no studies referred to a published protocol. We did not judge any of the studies to have a low risk of bias in all seven domains. We judged approximately two-thirds of the studies to have a high risk of bias in domains relating to 'blinding of participants and personnel' (performance bias) and 'blinding of outcome assessment' (detection bias).We found with moderate certainty, that distance BCVA with a blue-light filtering IOL, at six to 18 months postoperatively, and measured in logMAR, was not clearly different to distance BCVA with a non-blue-light filtering IOL (mean difference (MD) -0.01 logMAR, 95% confidence interval (CI) -0.03 to 0.02, P = 0.48; 2 studies, 131 eyes).There was very low-certainty evidence relating to any potential inter-intervention difference for the proportion of eyes that developed late-stage AMD at three years of follow-up, or any stage of AMD at one year of follow-up, as data derived from one trial and two trials respectively, and there were no events in either IOL intervention group, for either outcome. There was very low-certainty evidence for the outcome for the proportion of participants who lost 15 or more letters of distance BCVA at six months of follow-up; two trials that considered a total of 63 eyes reported no events, in either IOL intervention group.There were no relevant, combinable data available for outcomes relating to the effect on contrast sensitivity at six months, the proportion of eyes with a measurable loss of colour discrimination from baseline at six months, or the proportion of participants with adverse events with a probable causal link with the study interventions after six months.We were unable to draw reliable conclusions on the relative equivalence or superiority of blue-light filtering IOLs versus non-blue-light filtering IOLs in relation to longer-term effects on macular health. We were also not able to determine with any certainty whether blue-light filtering IOLs have any significant effects on MPOD, contrast sensitivity, colour discrimination, daytime alertness, reaction time or patient satisfaction, relative to non-blue-light filtering IOLs.

AUTHORS' CONCLUSIONS

This systematic review shows with moderate certainty that there is no clinically meaningful difference in short-term BCVA with the two types of IOLs. Further, based upon available data, these findings suggest that there is no clinically meaningful difference in short-term contrast sensitivity with the two interventions, although there was a low level of certainty for this outcome due to a small number of included studies and their inherent risk of bias. Based upon current, best-available research evidence, it is unclear whether blue-light filtering IOLs preserve macular health or alter risks associated with the development and progression of AMD, or both. Further research is required to fully understand the effects of blue-light filtering IOLs for providing protection to macular health and function.

Role of short-wavelength filtering lenses in delaying myopia progression and amelioration of asthenopia in juveniles

AIM

To evaluate the positive effects of blue-violet light filtering lenses in delaying myopia and relieving asthenopia in juveniles.

METHODS

Sixty ametropia juveniles (aged range, 11-15y) were randomized into two groups: the test group (30 children, 60 eyes), wearing blue-violet light filtering lenses; and the control group (30 children, 60 eyes), wearing ordinary aspherical lenses. Baseline refractive power of the affected eyes and axial length of the two groups was recorded. After 1-year, the patients underwent contrast sensitivity (glare and non-glare under bright and dark conditions), accommodation-related testing, asthenopia questionnaire assessment, and adverse reaction questionnaire assessment.

RESULTS

After 1y of wearing the filtering lenses, changes in refractive power and axial length were not significantly different between the two groups (P>0.05). Under bright conditions, the contrast sensitivities at low and medium-frequency grating (vision angles of 6.3°, 4.0°, and 2.5°) with glare in the test group were significantly higher than in the control group (P<0.05), while the contrast sensitivity at low-frequency grating (vision angles of 6.3° and 4.0°) in the absence of glare in the test group was higher than in the control group (P<0.05). Under glare and non-glare dark conditions, the contrast sensitivities of various frequencies in the test group did not show significant differences compared with those in the control group (P>0.05). In the test group, the amplitude of accommodation, accommodative lag, and accommodative sensitivity of patients wearing glasses for 6 and 12mo were significantly elevated (P<0.05), while the asthenopia gratings were significantly decreased (P<0.05). Nevertheless, in the control group, the amplitude of accommodation, accommodative lag, and accommodative sensitivity after 12mo were not significantly altered compared with baseline (P>0.05), and the asthenopia grating was not significantly decreased (P>0.05). In addition, after wearing glasses for 6 to 12mo, the asthenopia grating of patients in the test group decreased significantly compared with the control group (P<0.05). At 12mo, the constituent ratio of adverse reactions did not show significant difference between the two groups (P>0.05).

CONCLUSION

A 1-year follow-up reveal that compare with ordinary glasses, short-wavelength filtering lenses (blue/violet-light filters) increase the low- and medium-frequency contrast sensitivity under bright conditions and improved accommodation. They effectively relieved asthenopia without severe adverse reactions, suggesting potential for clinical application. However, no significant advantages in terms of refractive power or axial length progression were found compared with ordinary aspheric lenses.

Psychophysical Measurements of Luminance Contrast Sensitivity and Color Discrimination with Transparent and Blue-Light Filter Intraocular Lenses

Introduction

The purpose of this study was to measure luminance contrast sensitivity and color vision thresholdfs in normal subjects using a blue light filter lens and transparent intraocular lens material.

Methods

Monocular luminance grating contrast sensitivity was measured with Psycho for Windows (version 2.36; Cambridge Research Systems) at 3.0, 6.0, 12.0, 20.0, and 30.0 cycles per degree of visual angle (cpd) in 15 normal subjects (eight female), with a mean age of 21.6 years (SD = 3.8 years). Chromatic discrimination was assessed with the Cambridge colour test (CCT) along the protan, deutan, and tritan color confusion axes. Both tests were performed in a darkened room under two situations: with a transparent lens and with blue light filter lens. Subjective impressions were taken by subjects regarding their visual experience under both conditions.

Results

No difference was found between the luminance contrast sensitivity measured with transparent and blue light filter. However, 13/15 (87%) of the subjects reported more comfortable vision with the blue filter. In the color vision test, tritan thresholds were significantly higher for the blue filter compared with the transparent filter (p = 0.003). For protan and deutan thresholds no differences were found.

Conclusion

Blue-yellow color vision is impaired with the blue light filter, and no impairment occurs with the transparent filter. No significant differences in thresholds were found in the luminance contrast sensitivity comparing the blue light and transparent filters. The impact of short wavelength light filtering on intrinsically photosensitive retinal ganglion cells is also discussed.

Influence of yellow filters on straylight measurements

PURPOSE

To determine whether the yellow filters often used for glare reduction influence retinal straylight measured in healthy eyes.

SETTING

Department of Ophthalmology, Antwerp University Hospital, Edegem, Belgium.

DESIGN

Prospective case series.

METHODS

For each eye, the spherical equivalent (SE) was determined using an autorefractometer, followed by 5 straylight measurements taken with the compensation-comparison method. The first measurement was taken with a colorless plano lens placed in front of the eye, followed by 4 other measurements with yellow filters with cutoff wavelengths at 450 nm, 511 nm, 527 nm, and 550 nm. Ametropic volunteers were corrected using an additional lens in all measurements. Age, sex, and eye color were listed. In addition to the basic measurements, base- and age-corrected and base-, age-, and SE-corrected values were calculated.

RESULTS

The data from 56 right eyes of 56 healthy volunteers aged 28.7 years ± 10.3 (SD) were assessed. The straylight of the 4 yellow filters was significantly higher than that of the plano lens (P < .001, analysis of variance [ANOVA]). The straylight also increased with higher cutoff frequencies, albeit insignificantly (P > .05, ANOVA). No significant difference was found between sexes (P = .909) or between eye colors (P > .05).

CONCLUSIONS

The use of yellow filters increased retinal straylight by a small but significant amount compared with the use of unfiltered light. This suggests that the visual comfort often experienced while wearing these filters is not associated with reduced straylight.

A comparison of visual outcomes in three different types of monofocal intraocular lenses

AIM

To compare the visual outcomes (distance and near) in patients opting for three different types of monofocal intraocular lens (IOL) (Matrix Aurium, AcrySof single piece, and AcrySof IQ lens).

METHODS

The present study is a cross-sectional analysis of secondary clinical data collected from 153 eyes (52 eyes in Matrix Aurium, 48 in AcrySof single piece, and 53 in AcrySof IQ group) undergoing cataract surgery (2011-2012). We compared near vision, distance vision, distance corrected near vision in these three types of lenses on day 15 (±3) post-surgery.

RESULTS

About 69% of the eyes in the Matrix Aurium group had good uncorrected distance vision post-surgery; the proportion was 48% and 57% in the AcrySof single piece and AcrySof IQ group (P=0.09). The proportion of eyes with good distance corrected near vision were 38%, 33%, and 15% in the Matrix Aurium, AcrySof single piece, and AcrySof IQ groups respectively (P=0.02). Similarly, The proportion with good "both near and distance vision" were 38%, 33%, and 15% in the Matrix Aurium, AcrySof single piece, and AcrySof IQ groups respectively (P=0.02). It was only the Matrix Aurium group which had significantly better both "distance and near vision" compared with the AcrySof IQ group (odds ratio: 5.87, 95% confidence intervals: 1.68 to 20.56).

CONCLUSION

Matrix Aurium monofocal lenses may be a good option for those patients who desire to have a good near as well as distance vision post-surgery.

Effect on contrast sensitivity after clear, yellow and orange intraocular lens implantation

The objective of this study is to evaluate contrast sensitivity function (CSF) after clear, yellow- and orange-tinted intraocular lens (IOL) implantation. This was a prospective randomized study of 98 patients with senile cataract for a period of 6 months from day 1 of August 2014 to day 31 of January 2015. After phacoemulsification, 33 patients were implanted with clear IOLs (AcrySof UV-filtering IOL, SA60AT), 32 patients were implanted with yellow coloured IOLs (AcrySof Natural blue-light-attenuating and UV-filtering IOL, SN60AT with IMPRUV(®) filter) and 33 patients were implanted with orange-tinted blue-filtering IOLs (PC440Y Optech). After 1 month, monocular CSF was done under photopic (85 cd/m(2)) and mesopic (3 cd/m(2)) illumination condition with CSV-1000 test. The best corrected visual acuity (BCVA) after 1 month was 0.021 ± 0.058 logMAR for clear lens, 0.022 ± 0.059 logMAR for yellow lens and 0.019 ± 0.065 logMAR for orange lens (p = 0.989). Uniocular average photopic contrast sensitivity was 1.36 ± 0.19, 1.43 ± 0.18 and 1.46 ± 0.15 log units for clear lens, yellow lens and orange lens, respectively (statistically not significant; p = 0.076). Average mesopic contrast sensitivity was 1.02 ± 0.21 log units for clear lens, 1.00 ± 0.17 log units for yellow lens and 0.99 ± 0.15 log units for orange lens (statistically not significant; p = 0.771). Yellow or orange coloured blue-filtering IOLs are comparable to clear IOLs in terms of photopic and mesopic contrast sensitivity.

The Effect of Cataract Surgery on Circadian Photoentrainment: A Randomized Trial of Blue-Blocking versus Neutral Intraocular Lenses

PURPOSE

Cataract decreases blue light transmission. Because of the selective blue light sensitivity of the retinal ganglion cells governing circadian photoentrainment, cataract may interfere with normal sleep-wake regulation and cause sleep disturbances. The purpose was to investigate the effect of cataract surgery on circadian photoentrainment and to determine any difference between blue-blocking and neutral intraocular lenses (IOLs).

DESIGN

The study was a single-center, investigator-driven, double-masked, block-randomized clinical trial.

PARTICIPANTS

One eye in 76 patients with bilateral age-related cataract eligible for cataract surgery was included.

METHODS

Intervention was cataract surgery by phacoemulsification. Patients were randomized to receive a blue-blocking or neutral IOL.

MAIN OUTCOME MEASURES

Primary outcome was activation of intrinsic photosensitive ganglion cells using post-illumination pupil response (PIPR) to blue light from 10 to 30 seconds after light exposure as a surrogate measure. Secondary outcomes were circadian rhythm analysis using actigraphy and 24-hour salivary melatonin measurements. Finally, objective and subjective sleep quality were determined by actigraphy and the Pittsburgh Sleep Quality Index.

RESULTS

The blue light PIPR increased 2 days (17%) and 3 weeks (24%) after surgery (P < 0.001). The majority of circadian and sleep-specific actigraphy parameters did not change after surgery. A forward shift of the circadian rhythm by 22 minutes (P = 0.004) for actigraphy and a tendency toward an earlier melatonin onset (P = 0.095) were found. Peak salivary melatonin concentration increased after surgery (P = 0.037). No difference was detected between blue-blocking and neutral IOLs, whereas low preoperative blue light transmission was inversely associated with an increase in PIPR (P = 0.021) and sleep efficiency (P = 0.048).

CONCLUSIONS

Cataract surgery increases photoreception by the photosensitive retinal ganglion cells. Because of inconsistency between the significant findings and the many parameters that were unchanged, we can conclude that cataract surgery does not adversely affect the circadian rhythm or sleep. Longer follow-up time and fellow eye surgery may reveal the significance of the subtle changes observed. We found no difference between blue-blocking and neutral IOLs, and, because of the minor effect of surgery in itself, an effect of IOL type seems highly unlikely.

Effect of the color of the intraocular lens on optical and visual quality

Purpose: To analyze the optical quality of intraocular lenses (IOL) with an orange (PC440Y) and a yellow (SN60AT) filter, and correlate these results with the visual quality of patients with these implants. Setting: Fisabio Oftalmologνa Mιdica, Valencia, Spain. Design: Randomized prospective study. Materials and Methods: The IOL optical quality was determined using the modulation transfer function (MTF) and the spectral transmission. The visual quality of 87 eyes with cataract (51 with orange filter and 36 with yellow filter) was determined by best corrected visual acuity (BCVA) and contrast sensitivity function (CSF) under photopic and mesopic conditions. To analyze the results, we use a Student's t-test. Results: Orange lens filtered more of the blue spectrum (cut-off wavelength of 370 nm) than the yellow lens (390 nm). The MTF of the yellow lens was better than the orange lens (average modulation of 0.676 for natural and 0.672 for orange). The patients' BCVA was 0.02 + 0.10 logMAR for both lenses. The CSF obtained with the yellow lens was slightly better, although without statistically significant differences (P > 0.05). Conclusions: Both lenses are of good optical quality. The patients' visual quality was similar with both lenses, and optical quality was also similar. The color of the lens does not affect the visual quality of the patient.

Patient-Reported Difference following Implantation of a Blue Light-Filtering Aspheric Intraocular Lens and a UV-Filtering Aspheric Intraocular Lens

We report on a series of 6 patients who experienced yellow vision after uncomplicated cataract surgery in their second eye. In the first eye, an aspheric blue-light filtering intraocular lens (IOL) was implanted, followed by the implantation of a 1-Piece aspheric IOL in the second eye. The time between the surgeries ranged from 12 months to 3 years. The patients experienced noticeable differences between the yellow and the clear lens. It is suggested to avoid mixing blue light-filtering and UV-filtering IOLs in the same patient, particularly in those who have high expectations following cataract surgery.

Premium IOLs in Glaucoma

Advanced technology or premium intraocular lenses have been developed to meet the patient expectations of perfect distance and near vision without the need for spectacles. Careful patient selection is critical when implanting these implants. This brief review focusses mainly on multifocal and toric IOLs and their application and limitations in patients with glaucoma.

How to cite this article: Ichhpujani P, Bhartiya S, Sharma A. Premium IOLs in Glaucoma. J Current Glau Prac 2013;7(2): 54-57.

[Refractive predictability and stability of three-piece versus single-piece intraocular lenses in patients with high axial myopia]

BACKGROUND

Based on previous data on single-piece and three-piece intraocular lenses (IOLs) there is no evidence for significant differences in decentration, tilt and refractive shift. The purpose of the current study was to compare single-piece and three-piece IOLs in patients with high axial myopia.

MATERIAL AND METHODS

A total of 68 eyes of 50 patients with high axial myopia (axis length ≥ 28.00 mm) with and without cataract who underwent complication-free phacoemulsification and IOL implantation were retrospectively examined. To compare single-piece and three-piece IOLs, the patients were retrospectively grouped depending on IOL type: group 1 acrylic single-piece IOL (n = 37; ACR6D SE, Corneal, France) and group 2 acrylic three-piece IOL with fixed haptic frame (n = 31; AF-1 UY, Hoya, Japan). Patient files were analyzed regarding best spectacle-corrected visual acuity (BSCVA), refractive predictability and stability.

RESULTS

In this study the mean BSCVA was determined as 0.22 ± 0.12 logMAR and 0.13 ± 0.11 logMAR 6 months postoperatively for the ACR6D SE group and the AF-1 UV group, respectively (p = 0.09). Refractive predictability was less accurate in the ACR6D SE (+ 1.75 ± 2.2 dpt) compared to the AF-1 UV (- 0.37 ± 1.1) treated eyes (p = 0.001). Refractive stability, defined as the difference in diopters between the first week and the sixth month after surgery, resulted in  + 0.40 ± 1.7 dpt and -0.16 ± 1.2 dpt for the ACR6D SE and the AF-1 UV, respectively (p = 0.022).

CONCLUSIONS

The three-piece AF-1 UV showed satisfactory refractive predictability and stability in patients with high axial myopia. The ACR6D SE has a high refractive unpredictability and should not be used in eyes with high axial myopia.

Comparison of blue light-filtering IOLs and UV light-filtering IOLs for cataract surgery: a meta-analysis

BACKGROUND

A number of published randomized controlled trials have been conducted to evaluate visual performance of blue light-filtering intraocular lenses (IOL) and UV light-filtering intraocular lenses (IOL) after cataract phacoemulsification surgery. However, results have not always been consistent. Therefore, we carried out a meta-analysis to compare the effectiveness of blue light-filtering IOLs versus UV light-filtering IOLs in cataract surgery.

METHODS AND FINDINGS

Comprehensive searches of PubMed, Embase, Cochrane Library and the Chinese BioMedical literature databases were performed using web-based search engines. Fifteen trials (1690 eyes) were included for systematic review, and 11 of 15 studies were included in this meta-analysis. The results showed that there were no significant differences in postoperative mean best corrected visual acuity, contrast sensitivity, overall color vision, or in the blue light spectrum under photopic light conditions between blue light-filtering IOLs and UV light-filtering IOLs [WMD = -0.01, 95%CI (-0.03, 0.01), P = 0.46; WMD = 0.07, 95%CI (-0.04, 0.19), P = 0.20; SMD = 0.14, 95%CI (-0.33, 0.60), P = 0.566; SMD = 0.20, 95%CI (-0.04, 0.43), P = 0.099]. However, color vision with blue light-filtering IOLs was significantly reduced in the blue light spectrum under mesopic light conditions [SMD = 0.74, 95%CI (0.29, 1.18), P = 0.001].

CONCLUSION

This meta-analysis demonstrates that postoperative visual performance with blue light-filtering IOLs is approximately equal to that of UV light-filtering IOLs after cataract surgery, but color vision with blue light-filtering IOLs demonstrated some compromise in the blue light spectrum under mesopic light conditions.

Effect of blue-light filtering on multifocal visual-evoked potentials

PURPOSE

To perform an objective functional assessment of the impact of blue-light filters on cortical processing to evaluate the potential side effects of the filters on higher tier visual function at the neural level.

SETTING

Department of Ophthalmology, Otto-von-Guericke-University Magdeburg, Magdeburg, Germany.

DESIGN

Cohort study.

METHODS

Multifocal pattern-reversal visual-evoked potentials (multifocal VEPs) were recorded monocularly in pseudophakic patients with a clear intraocular lens (IOL) under 2 conditions: (1) stimulus perception through a yellow filter with the filter characteristics of an AF-1 YA-60BB IOL (blue filtering); (2) stimulus perception through a neutral filter that homogeneously attenuates the effective stimulus intensity as under the blue-light filtering condition but independent of the wavelength (neutral filtering). Second-order kernel multifocal VEPs were extracted for 60 visual field locations, and amplitude and latency effects were determined for 6 stimulus eccentricities.

RESULTS

The study evaluated 20 patients. Typical multifocal VEPs were obtained for the blue-light and neutral filtering conditions at all eccentricities. No significant effects on amplitudes were obtained, and a subtle latency effect (<0.5 millisecond delay for neutral filtering; P<.02) did not reach significance in an eccentricity-specific analysis.

CONCLUSIONS

The induced short-term change in the spectral composition of the visual stimulus left neural activity at the level of the primary visual cortex largely unaffected, providing an objective account of the integrity of visual processing under this condition.

Recent studies provide an updated clinical perspective on blue light-filtering IOLs

Background

Recent reviews of blue light-filtering intraocular lenses (IOLs) have stated their potential risks for scotopic vision and circadian photoentrainment. Some authors have challenged the rationale for retinal photoprotection that these IOLs might provide. Our objective is to address these issues by providing an updated clinical perspective based on the results of the most recent studies.

Methods

This article evaluates the currently available published papers assessing the potential risks and benefits of blue light-filtering IOLs. It summarizes the results of seven clinical and two computational studies on photoreception, and several studies related to retinal photoprotection, all of which were not available in the previous reviews. These results provide a clinical risk/benefit analysis for an updated review for these IOLs.

Results

Most clinical studies comparing IOLs with and without the blue light-filtering feature have found no difference in clinical performance for; visual acuity, contrast sensitivity, color vision, or glare. For blue light-filtering IOLs, three comparative clinical studies have shown improved contrast sensitivity and glare reduction; but one study, while it showed satisfactory overall color perception, demonstrated some compromise in mesopic comparative blue color discrimination. Comparative results of two recent clinical studies have also shown improved performance for simulated driving under glare conditions and reduced glare disability, better heterochromatic contrast threshold, and faster recovery from photostress for blue light-filtering IOLs. Two computational and five clinical studies found no difference in performance between IOLs with or without blue light-filtration for scotopic vision performance and photo entrainment of the circadian rhythm. The rationale for protection of the pseudophakic retina against phototoxicity is discussed with supporting results of the most recent computational, in-vitro, animal, clinical, and epidemiological investigations.

Conclusions

This analysis provides an updated clinical perspective which suggests the selection of blue light-filtering IOLs for patients of any age, but especially for pediatric and presbyopic lens exchange patients with a longer pseudophakic life. Without clinically substantiated potential risks, these patients should experience the benefit of overall better quality of vision, reduced glare disability at least in some conditions, and better protection against retinal phototoxicity and its associated potential risk for AMD.

Electronic supplementary material

The online version of this article (doi:10.1007/s00417-011-1697-6) contains supplementary material, which is available to authorized users.

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

PURPOSE

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.

SETTING

Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University; Beijing Ophthalmology & Visual Sciences Key Laboratory, Beijing, China.

DESIGN

Prospective comparative clinical study.

METHODS

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.

RESULTS

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).

CONCLUSION

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

PURPOSE

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.

SETTING

Ludwig Boltzmann Institute of Retinology and Biomicroscopic Laser-Surgery, Department of Ophthalmology, Rudolf Foundation Clinic, Vienna, Austria.

DESIGN

Comparative case series.

METHODS

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).

RESULTS

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).

CONCLUSIONS

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.

Accelerated 20-year sunlight exposure simulation of a photochromic foldable intraocular lens in a rabbit model

PURPOSE

To assess the long-term biocompatibility and photochromic stability of a new photochromic hydrophobic acrylic intraocular lens (IOL) under extended ultraviolet (UV) light exposure.

SETTING

John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, USA.

DESIGN

Experimental study.

METHODS

A Matrix Aurium photochromic IOL was implanted in right eyes and a Matrix Acrylic IOL without photochromic properties (n = 6) or a single-piece AcrySof Natural SN60AT IOL (n = 5) in left eyes of 11 New Zealand rabbits. The rabbits were exposed to a UV light source of 5 mW/cm(2) for 3 hours during every 8-hour period, equivalent to 9 hours a day, and followed for up to 12 months. The photochromic changes were evaluated during slitlamp examination by shining a penlight UV source in the right eye. After the rabbits were humanely killed and the eyes enucleated, study and control IOLs were explanted and evaluated in vitro on UV exposure and studied histopathologically.

RESULTS

The photochromic IOL was as biocompatible as the control IOLs after 12 months under conditions simulating at least 20 years of UV exposure. In vitro evaluation confirmed the retained optical properties, with photochromic changes observed within 7 seconds of UV exposure. The rabbit eyes had clinical and histopathological changes expected in this model with a 12-month follow-up.

CONCLUSIONS

The new photochromic IOL turned yellow only on exposure to UV light. The photochromic changes were reversible, reproducible, and stable over time. The IOL was biocompatible with up to 12 months of accelerated UV exposure simulation.

Color discrimination by patients with different types of light-filtering intraocular lenses

PURPOSE

To evaluate photopic and mesopic color discrimination in patients with different types of light-filtering intraocular lenses (IOLs).

SETTING

Peking University Third Hospital, Peking University Eye Center, Beijing, China.

METHODS

Cataract patients with different types of IOLs were enrolled 3 months postoperatively. Overall and partial color discrimination under photopic (1000 lux) and mesopic (40 lux) conditions were evaluated with the Farnsworth-Munsell (FM) 100-hue test. Corrected distance visual acuity (CDVA) was tested under both conditions. Subjective visual quality was assessed with the 25-item National Eye Institute Visual Functioning Questionnaire (NEI VFQ-25).

RESULTS

The study evaluated 43 patients with a blue light-filtering IOL (15 photochromic, 13 yellow tinted) or an IOL filtering ultraviolet light only (n = 15). The difference in the FM 100-hue total error scores under photopic or mesopic conditions was not statistically significant between groups. There were no statistically significant differences in partial error scores in the 10 bands of the FM 100-hue color circle under photopic conditions. Under mesopic condition, there were statistically significant differences in partial error scores in the green to blue-green band (color caps 36 to 46) and the blue-green to blue band (color caps 46 to 54) (P = .005 and P = .030, respectively). There were no statistically significant differences in mean overall or subheading NEI VFQ-25 scores.

CONCLUSIONS

Filtering blue lights under mesopic conditions seemed to modify color discrimination in the green-to-blue bands postoperatively. The modification did not disturb overall color discrimination or cause subjective discomfort.

Cataract surgery with implantation of an artificial lens

BACKGROUND

Cataract surgery, the most frequently performed operative procedure worldwide, typically concludes with the implantation of an artificial intraocular lens (IOL) to correct aphakia (absence of the crystalline lens).

METHOD

Selective literature review including current regulations, guidelines and recommendations for cataract surgery.

RESULTS

The main symptom of cataract is loss of visual acuity, which usually progresses slowly. It can arise in one eye or both. There is a basic distinction between congenital and acquired cataracts. The probability of developing a cataract rises with age because of biochemical aging processes. The development of a cataract becomes highly likely from the sixth decade of life onward.

CONCLUSIONS

As no effective medications for cataract are available at present, its current standard treatment is the removal of the clouded lens. In industrialized countries, this is usually done with ultrasound (phacoemulsification), followed by the implantation of an IOL.