Mesopic Conditions Research Articles

Evaluation of contrast sensitivity and color vision in lead and zinc mine workers

Purpose. This study was performed to determine achromatic contrast sensitivity and color vision in lead and zinc mine workers. Methods. A total of 230 male workers, who had been working in mine and had been in contact with minerals for at least 1 year, were considered as the case group, and the age of 90 years matched men who have not been in contact with minerals, being regarded as the control group. Contrast sensitivity was assessed using the Freiburg test at three frequencies of 1, 5 and 15 cycles of degree and under low mesopic light condition by two gratings and Landolt C stimuli. Color vision was assessed using the Farnsworth D-15 test under high mesopic light condition. Both tests were carried out monocularly. Data were analyzed using version 22 SPSS software. Results. There was a significant difference between studied groups with Landolt C stimulus in all three frequencies 1, 5 and 15 cycles per degree (p=0.009, p=0.016 and p=0.003). With Grating stimulus, there was a significant difference between the two groups in frequencies of 1 and 15 cycles per degree but at frequency of 5 cycles per degree, there was a border difference (p<0.0001, p=0.051 and p=0.008). A significant difference was observed between color confusion indexes of the two groups (p<0.0001). Conclusion. Chronic exposure to mineral in lead and zinc mine may cause color vision deficiency and decrease in contrast sensitivity. It is recommended that Farnsworth D-15 and Freiburg contrast sensitivity tests would be involved in the early diagnosis of neurodegenerative and visual disorders in workers exposed to minerals.

Comparing Visual Acuity, Low Contrast Acuity and Contrast Sensitivity After Trifocal Toric and Extended Depth of Focus Toric Intraocular Lens Implantation.

PurposeThe aim of this study was to compare visual acuity at various distances (far, intermediate and near), low contrast acuity and contrast sensitivity after trifocal toric and extended depth of focus (EDOF) toric intraocular lens (IOL) implantation.Patients and MethodsThis was a non-interventional two-arm comparative study of visual outcomes after uncomplicated bilateral cataract or refractive lens exchange surgery with IOL implantation between 6 months and 5 years before a single diagnostic examination visit. There was no masking and no control group. Subjects had to have uncorrected distance visual acuity (UDVA) of 20/40 (0.3 logMAR) or better measured at the time of their study visit. Clinical evaluations included the manifest refraction, visual acuity (VA) at distance, intermediate (60 cm) and near (40 cm), low contrast (10%) VA and contrast sensitivity.ResultsA total of 50 bilaterally implanted patients (25 trifocal, 25 EDOF) were examined; the two groups had similar characteristics, including corneal astigmatism. Postoperative refractive outcomes were also similar. There were no statistically significant differences in distance or intermediate VA between groups, but the trifocal group had significantly better near VA both uncorrected (p = 0.009) and distance-corrected (p = 0.014). There were no statistically significant differences in the low contrast acuity measures between IOLs at either distance or 40 cm, with or without glare. Contrast sensitivity in mesopic and photopic conditions was similar.ConclusionThe trifocal and EDOF toric IOLs performed similarly for all measures except near VA, where the trifocal toric provided significantly better acuity. For subjects interested in reducing spectacle independence at near, this may be an important consideration.

Visual performance comparison of 2 extended depth-of-focus intraocular lenses

To compare the visual acuity and satisfaction outcomes of 2 different concepts of extended depth-of-focus intraocular lenses (EDOF IOLs). University Eye Hospital Bochum, Germany. Prospective randomized comparative clinical trial. Patients undergoing cataract surgery with the implantation of 2 different concept EDOF IOLs. In the first group (IC-8 Group), a monofocal 1-piece Tecnis Z B00 IOL (Johnson & Johnson Vision Care, Inc.) was implanted in the dominant eye, and an IC-8 IOL (AcuFocus) was implanted in the nondominant eye. In the second group (Symfony Group), a Tecnis Symfony IOL (Johnson & Johnson Vision Care, Inc.) was implanted in both eyes. The target refraction of the dominant eye was emmetropia and slight myopia (mini-monovision, -0.75 diopters) in the nondominant eye. Visual and refractive outcomes and patient satisfaction rates were evaluated 3 months postoperatively. This study comprised 76 eyes of 38 patients. No intraoperative or postoperative complications occurred in either group. Target refraction was reached in both groups without statistically significant differences. The uncorrected distance visual acuity (UDVA, photopic and mesopic light conditions) was excellent in both groups with statistically significantly better results in the IC-8 goup (logarithm of the minimum angle of resolution; IC-8 Group (0.1 ± 0.07 logarithm of the minimum angle of resolution [logMAR]; Symfony Group 0.07 ± 0.1 logMAR, P value .02 [photopic]; IC-8 group 0.12 ± 0.09 logMAR, Symfony group 0.22 ± 0.1 logMAR, P value < .01 [mesopic]). Binocular uncorrected intermediate visual acuity (UIVA) and uncorrected near visual acuity (UNVA) were also good in both groups without statistically significant differences (UIVA: IC-8 Group, 0.01 ± 0.07 logMAR, Symfony Group 0.01 ± 0.08 logMAR, P value .35; UNVA: IC-8 Group 0.14 ± 0.11, Symfony Group 0.09 ± 0.08, P value .14). Subjective satisfaction was high in both groups. Both EDOF IOLs provided a very good UDVA with superior results in the IC-8 Group, and a good UIVA and UNVA under photopic light conditions. Subjective patient satisfaction was higher in the IC-8 Group.

Comparison of contrast sensitivity between three aspheric acrylic monofocal intraocular lenses: a prospective randomised trial

Introduction: Evolution of cataract surgery and implantation of intraocular lenses (IOL) with new technological designs to optimise functional vision has been the aim of cataract surgery today. Aspherical lens design is a new lens technology to counteract spherical aberration exerted by a conventional IOL.&#x0D; Purpose: To compare the contrast sensitivity after cataract surgery between aspheric IOLs with negative spherical aberration (Tecnis ZA9003TM and AcrySof IQTM) and zero spherical aberration IOLs (Akreos Adapt Advance Optic [AO]TM).&#x0D; Study design: Interventional, single-blinded, randomised controlled trial.&#x0D; Methods: Ninety-six patients were recruited with 32 eyes in each study arm. All patients underwent standard phacoemulsification with implantation of an aspheric acrylic IOL randomised to one of the three lens models by a single experienced surgeon. Pre- and postoperative contrast sensitivity was analysed using the CSV1000E chart under photopic and mesopic conditions with and without glare testing.&#x0D; Results: All three lenses showed statistically significant improvement in contrast sensitivity postoperatively at all spatial frequencies under photopic, mesopic, and scotopic conditions with glare. There was no statistically significant difference between the groups. Tecnis ZA9003TM showed marked improvement in mesopic contrast sensitivity at 18 cycles/degree (cpd) at 12 weeks (p &lt; 0.05). The zero aberration Akreos Adapt AOTM showed better photopic contrast sensitivity compared to mesopic contrast sensitivity (p &gt; 0.05).&#x0D; Conclusion: AcrySof IQTM, Akreos Adapt AOTM, and Tecnis ZA9003TM performed equally well in contrast sensitivity at all spatial frequencies under photopic and mesopic conditions with and without glare testing. All lenses had statistically significant improvement in contrast sensitivity after cataract surgery. The negative aberration IOL Tecnis ZA9003TM showed marked improvement in mesopic contrast sensitivity at 18 cpd at 12 weeks. The zero aberration IOL, Akreos Adapt AOTM showed better photopic contrast sensitivity compared to mesopic contrast sensitivity.

A comparative study on early vision quality after implantation of refractive segmental and diffractive multifocal intraocular lens.

Objectives:To compare early subjective and objective vision quality of postoperative patients undergoing phacoemulsification cataract surgery combined with implantation of refractive segmental multifocal intraocular lens (MIOL) SBL-3 and apodized diffractive MIOL SN6AD1.Methods:As a prospective study, it enrolled 53 patients (53 eyes) to undergo phacoemulsification cataract surgery combined with MIOL implantation. According to differences in MIOL implanted, patients were divided into a SBL-3 group (25 eyes) and a SN6AD1 group (28 eyes). Ophthalmological evaluation included uncorrected (UDVA) and corrected (CDVA) distance visual acuities, uncorrected intermediate (UIVA) and near (UNVA) visual acuities, distance-corrected intermediate (DCIVA) and near (DCNVA)visual acuities and corrected near(CNVA) visual acuity, contrast sensitivity, modulation transfer function (MTF) and high order aberration (4 mm pupil diameter) at three months postoperatively. Moreover, a questionnaire survey was carried out to assess near spectacle independence, patient satisfaction and symptoms of visual disturbance.Results:At three months after surgery, UIVA and UNVA in the SBL-3 group are statistically significantly superior to those of the SN6AD1 group (P>0.05). There was statistical difference in contrast sensitivity at four spatial frequencies (3, 6, 12, 18cycles/degree) under mesopic conditions and mesopic conditions with glare (P>0.05). The total ocular high order aberration, coma and trefoil were statistically significantly larger in the SBL-3 group than in the SN6AD1 group with 4.0 mm pupil diameters (P>0.05). Statistical differences were found in the MTF at spatial frequencies of 5, 10 and 15 cycles/degree between the groups. There were no significant differences in spectacle independence, patient satisfaction and visual disturbance between the groups (P>0.05).Conclusions:Both the two multifocal intraocular lens provided an excellent level of quality of vision three months postoperatively. However, the application effect of SBL-3 MIOL is superior to that of SN6AD1 MIOL as far as intermediate vision, near vision and contrast sensitivity are concerned.

Comparative analysis of the functional results after implantation of various diffractive trifocal intraocular lenses

To compare visual outcomes after implantation of two models of diffractive trifocal IOLs using various vision assessment systems. The study included 25 patients (25 eyes) who were implanted with AcrySof IQ PanOptix (TFN) and 25 patients (25 eyes) implanted with AT LISA tri 839 MP (TRI). Postoperative examination at 1 year included assessment of monocular visual acuity for far, intermediate and near distance using decimal scale, as well as LogMAR and an interactive computer program (ICP). Contrast sensitivity was assessed with the Optec 6500 device. A questionnaire was used to evaluate subjective quality of vision and the intensity of optical phenomena. Uncorrected visual acuity (UCVA) at distance, intermediate and near was better in the TFN group in comparison with the TRI group as measured with decimal scale, ICP and LogMAR. Under photopic and mesopic conditions with and without glare, at all spatial frequencies the contrast sensitivity function (CSF) was higher after implantation of TFN in comparison with TRI. The average VF-14 score was 97.2 after implantation of TFN and 96.7 after implantation of TRI. The amount of patients who required spectacle correction after the surgery was 5.5% less in the TFN group compared to the TRI group. High visual outcomes at all distances were observed in patients after implantation of both trifocal IOLs with TFN showing a slight advantage. Evaluation of the visual outcomes using various systems showed the benefits of the ICP assessment. The CSF had typical configuration with maximum value in the mid-range region and a decrease in the high-frequency range after implantation of both IOLs, however the indicators were better in the TFN group. The postoperative period was characterized by high levels of patient satisfaction and spectacle independence in both groups.

Pupillodynamics and corneal spherical aberrations in a set of Indian cataract patients and its implications for aberrometric customisation of intraocular lenses.

Purpose:Assessment of pupil diameter in various light conditions and the corresponding corneal spherical aberrations in a cohort of Indian eyes with bilateral senile cataracts and the possible use of this data in aberrometric customization of intraocular lenses (IOLs).Methods:In this prospective observational study done at a tertiary eye care centre in India, the selected patients were subjected to measurement of their pupil diameters in scotopic, mesopic, and photopic conditions as well as the corresponding corneal spherical aberrations, using the Sirius Topographer (Costruzione Strumenti Oftalmici, Florence, Italy). Shapiro–Wilk test, Independent t-test, ANOVA with Bonferroni correction on post-hoc testing were used for statistical analysis.Results:104 eyes of 52 patients were enrolled for the study. The mean age was 53 ± 11.88 years. The mean scotopic, mesopic, and photopic pupil sizes were 4.37 mm (4.11–4.63 mm), 3.92 mm (3.71 mm–4.15 mm), and 3.37 mm (3.18–3.67 mm), respectively. There was a statistically significant difference (P = <0.001) in the mean corneal spherical aberration measured at the 6 mm zone (0.23 ± 0.02 microns) and at the 4 mm zone (0.06 ± 0.01 microns).Conclusion:The mean corneal spherical aberration corresponding to the average mesopic pupil size of our patient population was substantially lower than that of the scotopic pupil size and also less than the amount corrected by most of the negative aspheric IOLs. This perhaps indicates the need for customising IOLs based on the spherical aberrations of cornea at the zone corresponding to the mesopic pupil diameter for optimal residual total postoperative spherical aberrations.

Nighttime driving: visual, lighting and visibility challenges.

Nighttime driving is dangerous and is one of the most challenging driving situations for most drivers. Fatality rates are higher at night than in the day when adjusted for distances travelled, particularly for crashes involving pedestrians and cyclists. Although there are multiple contributory factors, the low light levels at night are believed to be the major cause of collisions with pedestrians and cyclists at night, most likely due to their reduced visibility. Understanding the visibility problems involved in nighttime driving is thus critical, given the increased risk to road safety. This review discusses research that highlights key differences in the nighttime road environment compared to the day and how this affects visual function and driving performance, together with an overview of studies investigating how driver age and visual status affect nighttime driving performance. Research that has focused on the visibility of vulnerable road users at nighttime (pedestrians and cyclists) is also included. Collectively, the research evidence suggests that visual function is reduced under the mesopic lighting conditions of night driving and that these effects are exacerbated by increasing age and visual impairment. Light and glare from road lighting and headlights have significant impacts on vision and night driving and these effects are likely to change with evolving technologies, such as LED streetlighting and headlights. Research also highlights the importance of the visibility of vulnerable road users at night and the role of retroreflective clothing in the 'biomotion' configuration for improving their conspicuity and hence safety.

Clinical outcomes of a novel presbyopia-correcting soft contact lens with a small aperture

PurposeTo investigate the efficacy and safety of a newly developed pinhole soft contact lens (Eyelike Pinhole II; Koryo Eyetech Co. Ltd.) for presbyopia correction. MethodsThis prospective clinical study enrolled 29 patients with presbyopia between October 2018 and December 2018. All participants wore the Eyelike Pinhole II in the non-dominant eye for >3 h/day for a period of 1 week. Binocular and monocular uncorrected near visual acuities, distance-corrected near visual acuity (DCNVA), uncorrected distance visual acuity, and corrected distance visual acuity (CDVA) were measured before and after the intervention. All visual acuities were measured in logarithm of the minimal angle of resolution (logMAR) units. In addition, binocular defocus curves were generated, and contrast sensitivity values were obtained under photopic and mesopic conditions before and after lens wear. ResultsThe mean DCNVA of the treated eye and the mean binocular DCNVA improved from 0.34 ± 0.12 to 0.15 ± 0.14 (P < 0.001) and 0.31 ± 0.13 to 0.11 ± 0.10 (P < 0.001) logMAR, respectively, after pinhole contact lens wear. Although the mean CDVA of the treated eye deteriorated from −0.04 ± 0.05 to 0.02 ± 0.11 logMAR (P = 0.015), there was no significant change in the mean binocular CDVA (P = 0.79). The binocular defocus curve showed a significant improvement from −5.0 dioptres (D) to −1.0 D after pinhole contact lens wear. ConclusionsThe newly developed Eyelike Pinhole II soft contact lens showed safe and effective outcomes; thus, it could be a promising option for the treatment of presbyopia.

Функциональные результаты оптимизированной асферической технологии с использованием номограммы в сравнении с асферическим и стандартным алгоритмом у пациентов с миопией на отечественной эксимерлазерной установке «Микроскан-Визум»

Purpose. Comparison of FOZ (Functional-Optical Zone), Spatial-Contrast Sensitivity (SCS) under various illumination conditions, evaluation of efficacy, safety, predictability and stability in correction of myopia using the MicroScan-Visum unit in patients of comparative, control and main study groups. Material and methods. The results of FemtoLasik operations were analyzed in 78 patients with myopia (130 eyes), which were divided into the following groups: ≪Nomogram≫ (50 eyes) – the calculation was made according to the nomogram developed by the authors; ≪Aspheric≫ (30 eyes), where Q was 0.2; ≪Standard≫ (50 eyes) – using the standard method. Results. In the Nomogram group, the uncorrected visual acuity (UCVA) was 1.08±0.04, the Aspheric group – 1.06±0.02, the Standard group – 1.04±0.03. In the Nomogram group, average FOZ (functional-optical zone) value was 5.71±0.09 mm, in the Aspheric group – 5.61±0.12 mm, in the Standard group – 5.38±0,75 mm. Statistically significant differences in FOZ values between the Aspheric and Nomogram groups in the area of moderate and high myopia were 5.18±0.12 mm and 5.52±0.08 mm, respectively. The visual acuity in all light conditions by 6th month was higher than the preoperative one in all the groups except the Standard group. In the SCS analysis under photopic conditions with and without light a growth of indicators in all groups at all frequencies was observed. By 6th month under mesopic conditions without light for the Aspheric and Nomogram groups a SCS recovery was noted, with difference at 18 cyclo/deg frequency, with a slight decrease for the Aspheric group, and an increase for the Nomogram group. In the mesopic conditions with light in the Aspheric and Nomogram groups, the SCS values increased on high frequencies almost twice as opposed to the preoperative level, and also the values of the Nomogram group increased twofold as opposed to those of the Aspheric group. Conclusion. The Nomogram group showed the best characteristics of efficiency, safety, predictability and stability as opposed to the comparative and control groups.

Reliability of Mesopic Measures of Visual Acuity and Contrast Sensitivity and Their Correlation with Rod and Cone Function in Retinitis Pigmentosa

Background: Mesopic conditions elicit both rod and cone responses, and they are more commonly encountered in daily life than are scotopic conditions; yet visual function outcome measures of mesopic visual acuity (VA) or contrast sensitivity (CS) are rarely evaluated. Objective: In retinitis pigmentosa (RP), we explored whether visual reductions in mesopic versus photopic conditions were correlated with cone or rod function, as well as the between-visit test-retest variability in mesopic measures. Methods: At each of two visits, 22 RP subjects completed mesopic and photopic ETDRS VA and Pelli-Robson chart CS tests obtained with and without a U23 NoIR 4% transmission filter; testing of perifoveal scotopic cone or rod sensitivity with the AdaptDx; and the Rabin Cone Contrast Test (CCT). Results: A greater CS reduction in mesopic versus photopic conditions was significantly related to absence of scotopic rod function (p = 0.038) or longer self-reported duration of night vision loss (p = 0.044). VA reductions >0.2 logMAR in mesopic versus photopic conditions were significantly related to reduced cone-mediated scotopic sensitivity (p = 0.038). Significant predictors of the CCT ratio of S-cone to M- and L-cone sensitivity were mesopic VA (p = 0.038) and absence of AdaptDx rod function (p = 0.008). Test-retest 95% coefficients of repeatability were not significantly different when comparing between photopic and mesopic tests of VA (0.16 and 0.12 logMAR, respectively) or CS (0.21 and 0.24 logCS, respectively). Conclusions: Perifoveal scotopic rod and cone function measured with the AdaptDx was significantly correlated with mesopic CS and VA, respectively, which had good, acceptable test-retest repeatability; thus, they appear to be suitable outcome measures to monitor mesopic visual function in clinical practice or trials. RP subjects with reduced mesopic VA and no perifoveal rod function had a greater loss of sensitivity for S-cones than for L-/M-cones.

Monovision with a Bifocal Diffractive Multifocal Intraocular Lens in Presbyopic Patients: A Prospective, Observational Case Series

We report the visual outcomes and patient satisfaction after bilateral implantation of a bifocal diffractive intraocular lens with monovision. Prospective, observational case series. Twenty-one subjects underwent cataract surgery or refractive lens exchange with bilateral implantation of the ZMB00 intraocular lens, with the dominant eye and nondominant eye targeted for plano and-1.25 to-1.00 diopters, respectively. Postoperative assessments included visual acuity (VA) at various distances under photopic and mesopic conditions; defocus curve, contrast sensitivity, and stereopsis; and Visual Function Questionnaire-25 and supplementary questionnaire. Mean binocular uncorrected VA at distance, intermediate (67cm), and near (30cm) were-0.03 ± 0.06, 0.12 ± 0.18, and 0.11 ± 0.05, respectively. No eyes lost >1 line of corrected distance VA. Binocular intermediate VA was significantly better in the uncorrected condition (P= .004) whereas binocular distance VA was better in the distance-corrected condition (P= .014). Near VA was similar in both conditions (P > .05). Stereoacuity and contrast sensitivity were within normal limits. All subjects had a composite score of ≥90 for vision-targeted items in the National Eye Institute Visual Function Questionnaire-25. Halos, glare, and starbursts occurred in 52%, 29%, and 24% of subjects, respectively. All subjects reported a satisfaction score of ≥3.5 of 5 and required no spectacles postoperatively. No intraocular lens exchange was required. Monovision with bilateral bifocal multifocal intraocular lens was safe and provided satisfactory vision at various distances, with good stereopsis and contrast sensitivity. Complete spectacle independence and high satisfaction score were achieved. In comparisonwith bilateral emmetropic bifocal multifocal intraocularlens, it provided better vision at intermediate and atvery near distances without inducing more dysphotopsia.

Comparison of contrast sensitivity based on the surgical results for intermittent exotropia.

To compare contrast sensitivity (CS) based on the surgical results for intermittent exotropia (IXT) and to examine the relationship between CS and photophobia. Medical records of the patients who underwent bilateral lateral rectus muscle recession for IXT between 4 and 12 years old were reviewed retrospectively. They were categorized based on the surgical results; successful correction group (n=36) and overcorrection group (esotropia ≥10 PD at 3mo postoperatively, n=18). Using CGT-2000 test for CS was performed binocularly, and subjective reports of photophobia was investigated preoperatively and at 3mo postoperatively. Objective photophobia was defined as a significant decrease in CS in the presence of glare. Preoperatively, there was no difference in CS between the groups. Postoperatively, under mesopic conditions, significant improvement of CS was observed at 6.3°, 4°, and 2.5° in the successful correction group and at 6.3° and 4° in the overcorrection group, regardless of glare. Under photopic conditions, at all visual angles except 0.64°, improvement in CS was noted in both groups while CS worsened significantly at 0.64° in the overcorrection group postoperatively. At all visual angles under photopic conditions postoperatively, regardless of glare, CS in the overcorrected group was significantly worse than that in the successful correction group, and CS was significantly decreased by addition of glare in both groups. All patients except one (96.4%) in the successful correction group and 8 patients (61.5%) in overcorrection group showed improvement of photophobia postoperatively, which correlated with CS under photopic conditions (P=0.001, 0.03). After surgery for IXT, CS under photopic conditions improve at all visual angles except 0.64°, while CS is significantly worse in the overcorrection group postoperatively at 0.64°. Subjective photophobia have significant correlation with CS under photopic conditions, and may be used as an objective indicator of photophobia.

An Alternative Psychophysical Diagnostic Indicator of the Aging Eye.

Purpose Impaired adaptation to changes in lighting levels as well as mesopic visual function is a common complaint in those over the age of 65. The use of photostress is a well-established method to test the adaption rate and the response of the visual cycle. In this study, we test visual function recovery to mesopic luminance stimuli following a long duration photostress in young and elderly subjects. If successful in strongly differentiating aging macular function, these methods may also be useful in the study of pathologies such as age-related macular degeneration. Methods A group of 12 older normal subjects (mean age 75.1 ± 4.79) and a control group of 5 younger normal subjects (mean age 26.2 ± 4.19) were subjected to macular photostress using the OraLux photostress system. The OraLux system provides a diffuse light source bleaching 84% of cone photopigment while maintaining an exposure safety factor of 200 times less than the maximum safe exposure. After each photostressing session, macular recovery was tracked using a foveal, variable contrast, flickering stimulus of mean luminance in the high mesopic range. Recovery was tracked for 300 seconds. The endpoint was time to recovery to each individual's baseline sensitivity as determined by two static sensitivity trials prior to photostress. Results Proportional hazards analysis of recovery time yielded a statistically significant difference between the older group and the young group (HR = 0.181; p=0.0289). The estimated hazard ratio of 0.181 indicates that older subjects return to baseline at less than one-fifth the rate of younger subjects. The hazards ratio remained statistically significant after adjusting for visual acuity (HR = 0.093; p=0.0424). Conclusion Photostress recovery of flicker sensitivity under mesopic conditions is a strong differentiator of aging macular function. This agrees with subject-reported complaints in reduced luminance conditions after exposure to bright lights such as night driving. The qualitative similarity between the aging retina and changes in early AMD suggests that flicker recovery following photostress may be useful as a surrogate endpoint in AMD clinical trials.

The effects of two longpass filters on visual performance

PurposeThis study compared visual performance and optical properties of three filters. MethodTwo groups of twenty adults were recruited: wearers of progressive addition lenses (PAL, 46–73 years) and wearers of single vision lenses (SVL, 26–55 years). Three spectacle filters (Hoya, Japan) were compared: clear control, Standard Drive (STD), and Professional Drive (PRO) lenses. Optical transmittance was measured by a Jasco V-650 spectrophotometer. Best corrected visual acuity (BCVA) was measured in photopic (BCVAphotopic) and mesopic (BCVAmesopic) conditions and under glare (BCVAglare). Photopic contrast sensitivity (CS) was also measured. ResultsThe three longpass filters show cutoff at 426±2nm (STD/PRO) and 405±2nm (clear lens). BCVAglare improved with Drive filters compared to the clear one (p<0.05) from 0.03 to -0.02 (STD) and to -0.01 (PRO) for PAL and from -0.08 to -0.12 (STD and PRO) for SVL. For PAL, BCVAmesopic improved from 0.15 to 0.12 (STD, p<0.05) and 0.13 (PRO), while no substantial difference was observed for SVL. CS showed some improvements with Drive lenses at some angular frequencies between 6 and 18 cycles/deg, mainly for the PAL group. No BCVAphotopic differences were found. After testing all filters, each for two weeks, 79% (PAL) and 60% (SVL) of participants preferred Drive lenses. ConclusionsDrive lenses are found to maintain or improve some visual functions compared to the clear lens. The improvement of mesopic visual acuity, visual acuity under glare, and contrast sensitivity is mainly attributed to the reduction of intraocular light scattering as a consequence of the total light attenuation in the spectral range below the cutoff.

Retinal Contrast Gain Control and Temporal Modulation Sensitivity Across the Visual Field in Glaucoma at Photopic and Mesopic Light Conditions.

Glaucoma affects many aspects of visual performance, including adaptation, and this may depend on ambient luminance. We determine the influence of glaucoma and luminance on temporal aspects of adaptation, specifically on contrast gain control and temporal modulation sensitivity (TMS). This case-control study included 12 glaucoma patients and 25 age-similar controls (50-70 years). Threshold perimetry was performed with a minimized testing grid (fovea and four peripheral locations). Stimuli (Goldmann size III 50 ms increment/decrement) were presented on a time-varying background with sinusoidally-modulated luminance (amplitude 60%; frequency 0-30 Hz; mean background luminance, 1 and 100 cd/m2). TMS (2.5-30 Hz) was measured in the same locations with a sinusoidally-modulated stimulus (Goldmann size IV, 334 ms) on a steady background (1 and 100 cd/m2). In healthy subjects, contrast sensitivity decreased with increasing background modulation frequency and increased again at very high frequencies, indicating contrast gain control. Minimum sensitivity was located between 2.5 and 20 Hz, depending on luminance and eccentricity. In glaucoma patients, the same frequency dependency was found (P = 0.12) but with an overall reduced sensitivity (P = 1 × 10-5), independent of luminance (P = 0.20). Decrements differentiated better between glaucoma and healthy subjects than increments (P = 0.004). TMS was reduced in glaucoma (P = 5 × 10-6) across all frequencies and luminance levels, with complete loss for high frequencies at 1 cd/m2. Contrast gain control is largely unaffected in glaucoma, suggesting intact amacrine cell function. Perimetry with decrements or a high-frequency stimulus on a low-luminance background seems best to differentiate between glaucoma and healthy subjects.

Blue light–filtering and violet light–filtering hydrophobic acrylic foldable intraocular lenses: Intraindividual comparison

To compare the clinical outcomes after cataract surgery and implantation of a blue light-filtering IOL (AcrySof IQ SN60WF) or a violet light-filtering intraocular lens (IOL) (OptiBlue ZCB00V). Four surgical sites in Japan. Prospective case series. One eye of patients with bilateral cataract was randomly allocated to the blue light-filtering IOL and the fellow eye to the violet light-filtering IOL. Visual acuity and contrast sensitivity were assessed over 3months. The incidence of cyanopsia was evaluated using the neutralization method. The study enrolled 110 eyes of 55 patients. There was no significant difference in visual acuity between the two IOLs. Based on the neutralization results 1week postoperatively, 15 cases (27.8%) with the light-filtering IOL and 8 cases (14.8%) with the violent light-filtering IOL had cyanopsia; the difference reached statistical significance (P=.049). After 2weeks, the difference in the incidence of cyanopsia was not significant. Postoperative contrast sensitivity under photopic condition at 1week and 3months and contrast sensitivity under mesopic conditions at 3months were significantly better with the violet light-filtering IOL than with the blue light-filtering IOL (P<.05). The violet light-filtering IOL yielded highly satisfactory clinical outcomes, including reduction of cyanopsia and a potential improvement in contrast sensitivity. The different chromophores of the IOL and its different material and design might have contributed.

The effect of tints on distance stereoacuity under varying retinal illuminations

Background: Stereopsis is the accurate awareness of relative depth necessary for efficient hand–eye coordination and navigation. A popular brand of sunglasses claims to enhance depth perception. Aim: This study set out to investigate the effect of tinted lenses on distance stereoacuity under varying retinal illumination. Setting: This study was set at the Discipline of Optometry, University of KwaZulu-Natal. Methods: A pretest–post-test research design was used. Forty participants were recruited using convenience sampling. The Howard–Dolman apparatus was used to measure distance stereoacuity with different tints of a popular sporting brand under varying retinal illumination. The tinted lenses and their respective transmission values used included persimmon (61%), light grey (38%), G30 (30%) and black iridium (10%). The placebo comprised of a white lens (100% transmission). Habitual distance stereoacuity was measured with no lens as the control. Retinal illumination was varied with neutral density filters to simulate mesopic and scotopic conditions. The Friedman and paired t -tests were used to analyse the data. Results: The mean stereoacuity for each lens was significantly different across the three retinal illumination levels ( p < 0.05). A statistically significant difference ( p = 0.012) was found with only the light grey tint under scotopic conditions when compared to the habitual stereoacuity. However, clinically significant differences were noted with the persimmon, light grey and black iridium tints. Overall, poorer stereoacuity was noted in mesopic and scotopic conditions compared to photopic for all five lenses. Conclusion: Tinted lenses used had no statistically significant effect on distance stereoacuity but clinically significant changes were noted. However, the change in retinal illumination adversely affected distance stereoacuity.

Influence of trifocal intraocular lenses on standard autorefraction and aberrometer-based autorefraction

To study the agreement between manifest refraction and objective refraction measured with two autorefractor models and an aberrometer in eyes implanted with a trifocal diffractive intraocular lens (IOL). IOA Madrid Innova Ocular, Madrid, Spain. Prospective comparative cohort study. An autorefractor keratometer (KR-8800), based on a Scheiner double pinhole, and a 3-dimension wavefront topography aberrometer system (OPD-Scan III), based on the scanning-slit retinoscopy principle, were used to obtain objective refraction readings. In addition, lower-order Zernike coefficients (Z) were used to calculate objective refraction. A set of 7 different results was obtained in power vector notation (spherical equivalent [SE], Jackson cross-cylinder, axes at 180 degrees and 90 degrees [J0] and Jackson cross-cylinder, axes at 45 degrees and 135 degrees [J45]) for 7 different methods: manifest refraction, autorefraction obtained with the autorefractor keratometer, WF-P (Z-based objective refraction for the photopic pupil), WF-M (Z-based objective refraction for the mesopic pupil), WF-4 (Z-based objective refraction for a 4.0mm pupil), OPD-C (autorefraction measured with the 3-dimension wavefront topography aberrometer system under photopic conditions), and OPD-M (autorefraction measured with the 3-dimension wavefront topography aberrometer system under mesopic conditions). The study comprised 102 eyes from 51 cataract patients who underwent binocular implantation of a diffractive trifocal IOL (FineVision POD F). All 6 objective methods yielded more negative SE values than manifest refraction (P<.001). As for the astigmatism components (J0 and J45), only autorefraction (P=.003) and OPD-M (P<.001) differed significantly from manifest refraction. The best and worst correlation for the SE component were intraclass correlation coefficient (ICC)=0.70 (for WF-M) and ICC=0.48 (for WF-4). Objective methods tend to yield more negative sphere values than manifest refraction.

Influence of refractive error on pupil diameters in highly myopic eyes with implantable collamer lenses.

To investigate the influence of refractive error on pupil diameters in highly myopic eyes with implantable collamer lenses. Shanghai, China. A prospective consecutive observational study. Sixty-six eyes of 66 patients that underwent ICL V4c implantation were included. Pupil diameters before and 1 week, 1 month, and 3 months after surgery were measured using an automatic pupillometry system (MonCv3; Metrovision, Pérenchies, France) under four standardized illumination conditions: 0, 1, 10, and 100 cd/m2. The correlations between changes in pupil diameter and spherical equivalent values and patient age were investigated. Based on preoperative spherical equivalent values, included eyes were divided into a high-myopia group (-6.3 to -9.9 D (diopters)) and a super-high-myopia group (-10 to -20 D). Pupil sizes remained unchanged after surgery in the high-myopia group and decreased at 1 and 10 cd/m2 in the super-high-myopia group. A between-group comparison showed that pupils were significantly smaller in the super-high-myopia group 1 week postoperatively under all illumination conditions and remained smaller at 1 month and 3 months under 1 and 10 cd/m2 lighting conditions. Preoperative spherical equivalent values were significantly correlated with the percent decrease in pupil diameter 1 week postoperatively under 0, 1, and 10 cd/m2 illumination conditions; the greater the degree of myopia, the greater the reduction in pupil diameter. Preoperative refractive error significantly affects pupil diameter in highly myopic eyes after implantable collamer lens implantation. Pupils of super highly myopic eyes remained smaller than preoperative levels under mesopic conditions after implantable collamer lens implantation.