Contrast Glare Research Articles

Effect of larger corneal spherical aberration in improving the near visual acuity of eyes implanted with the TECNIS Symfony.

To explore the effect of corneal spherical aberration on the visual acuity and visual quality of eyes implanted with the TECNIS Symfony intraocular lens (IOL). A total of 43 patients with age-related cataract (60 eyes) undergoing phacoemulsification and TECNIS Symfony IOL implantation were enrolled in this study. The uncorrected distance (UDVA), intermediate (UIVA), near visual acuity (UNVA), corrected distance visual acuity (CDVA), contrast sensitivity, and ocular spherical aberration were recorded 3 months after surgery. Preoperative and postoperative corneal spherical aberration were also measured using the iTrace device. Objective scattering index (OSI), modulation transfer function cut-off frequency (MTF cut-off), and Strehl ratio (SR) were measured by the Optical Quality Analyzing System. Catquest-9SF questionnaire were applied too. Spearman's correlation analysis was used to evaluate the relationship between spherical aberration and visual quality parameters. Patients were satisfied with their postoperatively visual quality. And the postoperative logMAR UDVA, UIVA, UNVA, and CDVA was 0.05 ± 0.07, 0.04 ± 0.06, 0.15 ± 0.07, and 0.03 ± 0.05, respectively. The mean preoperative corneal spherical aberration was 0.24 ± 0.10 μm, which is the only factor influencing postoperatively UNVA, and it was negatively correlated with UNVA and glare contrast sensitivity under 18 cpd (cycle/degree, cpd) spatial frequency (r = -0.403, -0.300, -0.360; all P < 0.05). Additionally, the greater the residual spherical aberration of the cornea, the better the near vision after operation. The mean postoperative ocular spherical aberration was -0.03 ± 0.07 μm, it was not correlated with visual acuity, contrast sensitivity, and visual quality (all P > 0.05). Preoperative positive spherical aberration can benefit near vision while decrease contrast sensitivities at high spatial frequencies when implanted with the TECNIS Symfony IOL.

Predicting glare from daylight through microstructures solar control systems using matrix-based simulation methods in Radiance

In this study the five-phase method and a parallelized invocation of evalglare has been used, to evaluate the performance of a microstructure and a Low-E window w/wo external blind, in terms of glare. The first part of the results investigates how Bidirectional-Scattering-Distribution-Functions, BSDF, and aBSDF (Aperture BSDF) properties bias the predicted glare through a microstructure, linking BSDF rank to saturation glare and resolution to contrast glare. The investigation found a combination of correct rank, low resolution and peak extraction (aBSDF) to be the best trade-off between speed and accuracy. The later comparison found none of the investigated systems to be sufficient glare protection. The microstructure was found to outperform the external blinds, using the current shading schedule (9% peak difference in occupied hours exceeding a DGP of 0.45).

Comparing performance of discomfort glare metrics in high and low adaptation levels

Current discomfort glare prediction metrics usually account for at least one of the two categories of effects that induce discomfort glare – the saturation and contrast effects. Saturation-driven metrics (overall illuminance on the eye) are suited for brightly lit scenes in general. On the contrary, contrast-driven metrics (luminance ratio in the field of view) usually perform better in high contrast conditions such as with small-sized bright glare sources. Only a few existing metrics consider both effects, such as the Daylight Glare Probability (DGP). However, even these “hybrid” metrics may underperform in conditions other than those considered when they were developed, such as in dim scenes with high contrast glare. This paper investigates the ability of current glare indicators to predict perceived discomfort glare in user-evaluated scenes depending on two different adaptation levels. Towards this end, we used a composite dataset of six laboratory studies performed previously and separately in various parts of the world. According to Receiver Operator Characteristics (ROC) findings and complementary statistical research, the hybrid metrics DGP and Eccologit perform best in both investigated ranges (dimmer and brighter scenes). For the single-effect metrics, the contrast-driven metrics appear to perform better than saturation-driven metrics in lower adaptation levels (dimmer scenes), while the reverse is seen in higher adaptation levels (brighter scenes). As a result, metrics that only consider one effect should be used with caution. Although hybrid metrics continue to perform well in the investigated scenes, further research is needed to extend their applicability to a larger variety of lighting conditions that may be observed in work environments.

The Effect of Night Glare on Myopia

Purpose : This study is to investigate the effect of night glare on myopia.Methods : Forty eight myopic eyes aged 20 to 30 year old were under the indoor illumination 1 lx or less for 5 minutes for the mesopic adaptation. Subjects were grouped by the equivalent spherical refraction -3.25 D. The group 1 with the refraction under -3.25 D and the group 2 with over -3.25 D were compared and analyzed. Two 100 Watt bulbs were placed by the side of the target whose illuminance at the position of subject's pupil was measured. The disability glare (contrast visual acuity and contrast sensitivity) was measured at 2, 5, and 10 lx and the discomfort glare was quantified by Deboer glare scale. The contrast acuity was measured by Reverse- Contrast chart at 100%, 25% and 10% of contrast LogMAR chart and the contrast sensitivity using the iPad program Clinic CSF 2.0 was measured at 3, 6, 12 and 18 cycles per degree.Results : The contrast acuity and contrast sensitivity of disability glare were both high in the group 1. The contrast acuity showed a significant difference after glare occurred (p 0.05).Conclusion : Considering the trend of higher nighttime activity in Korea, it is thought that not only a standard vision test for the night and the prescription to intervene the glare is needed regardless of age.

Flow of Light: Balancing Directionality and CCT in the Office Environment

ABSTRACT Human perception and vision have evolved in response to dynamic daylight, a combination of radiation from direct sunlight and diffuse skylight, which has created a flow of variations in light, in terms of direct:diffuse distribution, intensities and spectrum. This study investigates the qualities of the flow of light in an office after adding ceiling-mounted spotlights (32° tilt angle) to traditional diffuse ceiling panels. The intention is to create a flow of task light – a light-zone at each work-plane – complementing the directionality of the natural daylight inflow from the windows. An experiment was carried out in an office, in two parts. Four ratios of direct:diffuse light were tested by 30 people. Then one ratio was tested in five combinations of high, neutral and low color temperatures by 15 people in two daylight situations: overcast and clear sky. The visual light quality and perceived atmosphere of the office environment was tested through questionnaires, reaction cards and semi-structured interviews. The direct flow of light is recommended to be more than 15% of the total illuminance at the work-plane to provide the distinct visual appearance of modeling and a cozier atmosphere, which is preferable for socializing, and less than 45% to avoid glare and high contrast for visual tasks. Direct warm and diffuse cool lighting were perceived as the most natural but were not always preferred. There is an indication of slight preference for cooler ambient lighting in clear sky situations and warmer ambient lighting in overcast situations. Especially the preference in relation to sky conditions needs to be further investigated. A field study will implement these findings in a double dynamic lighting concept responding to daylight level and sky character. Strong individual preferences for combinations of color temperatures was identified, this open up new research areas for personalized flows of light in future dynamic lighting designs.

Visual fatigue during control room work in process industries.

BACKGROUND:Working in front of computer screens is visually demanding and related to adverse eye symptoms. Occurrence of glare further increases visual fatigue.OBJECTIVE:This paper presents results from an examination of visual ergonomics in control room environments at two Swedish process industries.METHODS:Visual conditions were examined and evaluated in nine control rooms and eighteen process operators answered questions about their perceived workload and visual experiences.RESULTS:When working in the control rooms, the mental workload was rated significantly higher by the participants, compared to experienced performance. The operators further experienced significantly higher visual fatigue and blurred vision compared to double vision and sore eyes. Visual demands were increased in conditions where contrast glare was present, as well as frequent changes of focusing distances, and low contrast between background and characters in computer screens.CONCLUSIONS:Suboptimal visual working conditions in the control rooms contributes to increased visual demands on the operators. Presence of glare is leading to visual fatigue and an unnecessary high mental load. The findings support the relevance of considering principles of general and visual ergonomics when designing and organizing work in control rooms. Workstation design should also be flexible to allow for individual and contextual adjustments.

Effect of central hole location in phakic intraocular lenses on visual function under progressive headlight glare sources

To analyze the effect of the central hole location in the V4c implantable collamer lens (ICL) on the quality of vision, including progressive headlight glare simulation and quality of life. IOBA-Eye Institute, Valladolid, Spain. Case series. The central hole location was determined by slitlamp and dual Scheimpflug imaging for 6months or more postoperatively. The visual acuity, mesopic contrast sensitivity, halogen glare contrast sensitivity, xenon glare contrast sensitivity, photostress recovery time after glare, de Boer scale, and Quality of Life Impact of Refractive Correction (QIRC) questionnaire results were evaluated. Multiple regression models were used to analyze the effect of the central hole location on parameters using the pupil center and visual axis as references based on Cartesian and polar coordinates. The safety index was 1.13 and the efficacy index, 1.12. Under all testing circumstances, central hole decentration did not affect the visual acuity or contrast sensitivity. With the visual axis as a reference, worse QIRC values were associated with greater upward central hole displacement (P=.03) and a lower polar angle value (P=.008); also, halogen glare discomfort was greater with a higher radius (P=.04). Using the pupil center as a reference, greater nasal central hole decentration was associated with longer xenon glare photostress recovery time (P=.002). Implantation of the ICL with a central hole yielded excellent visual outcomes, even under increasing glare sources, regardless of the hole's location. However, hole decentration might affect patient-perceived quality of life, bothersome halogen glare, and longer xenon glare photostress recovery time. Such complaints after the early postoperative period might be managed with discrete ICL centration if the central hole is decentered upward or nasally.

Daylight Discomfort Glare Evaluation with Evalglare: Influence of Parameters and Methods on the Accuracy of Discomfort Glare Prediction

Nowadays, discomfort glare indices are frequently calculated by using evalglare. Due to the lack of knowledge on the implications of the methods and parameters of evalglare, the default settings are often used. But wrong parameter settings can lead to inappropriate glare source detection and therefore to invalid glare indices calculations and erroneous glare classifications. For that reason, this study aims to assess the influence of several glare source detection methods and parameters on the accuracy of discomfort glare prediction for daylight. This analysis uses two datasets, representative of the two types of discomfort glare: saturation and contrast glare. By computing three different statistical indicators to describe the accuracy of discomfort glare prediction, 63 different settings are compared. The results suggest that the choice of an evalglare method should be done when considering the type of glare that is most likely to occur in the visual scene: the task area method should be preferred for contrast glare scenes, and the threshold method for saturation glare scenes. The parameters that should be favored or avoided are also discussed, although a deeper understanding of the discomfort glare mechanism and a clear definition of a glare source would be necessary to reliably interpret these results.

Comparison on visual quality of V4 and V4c cposterior chamber intraocular lens implantation for the correction of super high myopia

Objective To compare the visual quality after implantation phakic intraocular lens of ICL V4 and ICL V4c in patients with super high myopia. Methods The data of 84 eyes of 42 patients with super high myopia were selected. All patients were divided randomly into control group and observation group, with 42 eyes of 21 cases in each group.The control group were implanted with ICL V4, the observation group were implanted with ICL V4c. The visual quality of two groups were compared 3 months after treatment. Results The difference in uncorrected visual acuity after surgery was not statistically significant between the two groups (P=0.26). The BCVA after surgery improved ≥2 lines of control group was in 15 cases (71.4%) and the observation group in 16 cases(76.2%), the difference wasn’t statisti-cally significant between the two groups (P=0.32). The postoperative UCVA≥BCVA before surgery was in 19 cases(90.5%)of the control group and 20 cases(95.2%)of the observation group, the difference wasn’t statistically significant between the two groups (P=0.19). The difference of brightlight, dark light, bright light glare and dark glare contrast light sensitivity were not significant between the two groups (P>0.05). The higher order aberrations of the control group were (0.29±0.07)μm, and the observation group were (0.26±0.03)μm, and the difference was not significant between the two groups (P=0.37). Conclusion The difference is not significant in visual quality between ICL V4c and ICL V4 after surgery, but the patients with ICL V4c can avoid peripheral iridectomy. Key words: Myopia, super high; Phakic intraocular lens; ICL V4, ICL V4c; Visual quality

Tear lipid supplement prophylaxis against dry eye in adverse environments.

To compare the prophylactic efficacy of single application of lipid and non-lipid containing tear supplements, prior to exposure of symptomatic dry eye subjects to a simulated adverse environment. Thirty subjects with mild-to-moderate dry eye symptoms participated in the prospective, randomised, double-masked, paired-eye trial. A lipomimetic drop (Systane® Balance) was applied to one eye (randomised), and a non-lipid containing drop (Systane® Ultra) applied simultaneously to the contralateral eye. Subjects were subsequently exposed to a validated simulated adverse environment model created by a standing fan directed towards the eye, at a distance of 1m, for 2.5min. Low contrast glare acuity, lipid layer grade (LLG), non-invasive tear break-up time (NIBUT), temperature variation factor (TVF), and tear meniscus height (TMH) were evaluated at baseline, following eye drop instillation and following simulated adverse environment exposure. Both therapies resulted in increased NIBUT (both p<0.001), and prevented its decline below baseline with simulated adverse environment exposure (both p>0.05). However, only the lipomimetic drop increased LLG (p<0.001) and precluded its fall below baseline post-adverse environment exposure (p=0.15). Furthermore, post-instillation and post-exposure LLGs and NIBUT were significantly higher in the lipomimetic group (all p<0.05). No significant changes were observed in glare acuity, TVF and TMH (all p>0.05). More subjects (67%) reported greater ocular comfort in the eye receiving the lipomimetic. Single application of both lipid and non-lipid containing eye drops conferred protective effects against exposure to adverse environmental conditions in subjects with mild-to-moderate dry eye, although the lipomimetic demonstrated superior prophylactic efficacy.

Comparative study of visual function and ocular aberrations of two different one-piece designed hydrophilic acrylic intraocular lens.

To determine whether the aspherical IOL, Tecnis ZCB00, can improve the visual quality by measuring visual acuity, wavefront aberrations, and contrast sensitivity. It was a retrospective case series. Patients who underwent phacoemulsification cataract surgery were divided into two groups. One group (Group TC) was implanted with one-piece aspherical acrylic IOL (Tecnis ZCB00, AMO); the other (Group SA) was implanted with one-piece spherical acrylic IOL (Sensar AAB00, AMO). Eighty-eight eyes were selected into this study, among them 43 eyes in 26 male cases and 45 eyes in 29 female cases. Thirty-six eyes in 23 cases were in Group TC, and 52 eyes in 32 cases were in Group SA. Threemonths postoperatively, aberrations were analyzed with i-Trace visual function analyzer (Tracy Technologies, USA). Contrast sensitivities were measured with Takaci-CGT-1000 contrast glare tester (Seiko, Japan). All the 88 eyes underwent phacoemulsification with intraocular lens implantation, without complications during or after surgery. Threemonths postoperatively, the uncorrected vision acuity in Group TC was significantly better than in Group SA (P=0.007). At the pupil size of 5.0mm, higher-order aberrations in Group TC were significantly higher than in Group SA (P=0.02), especially the spherical aberration (Z 40 ) (P<0.001); at the pupil size of 4.0mm, Z 40 in Group SA was statistically higher than in Group TC (P<0.001); at the pupil size of 3.0mm, higher-order aberrations such as coma (Z 3-1,1 ) and trefoil aberration (Z 3-3,3 ) in Group SA were obviously higher than in Group TC (P=0.01). In the low spatial frequency, the contrast sensitivity and the glare sensitivity in Group TC were significantly higher than in Group SA (P<0.05). By the short-term follow-up (3months), the aspherical acrylic IOL can reduce the higher-order aberrations (especially the spherical aberration) and increase the contrast sensitivity to improve the visual performance.

Compatibility of phospholipid liposomal spray with silicone hydrogel contact lens wear.

To assess the effects of two weeks of regular phospholipid liposomal spray application on lipid layer grade, tear film stability, subjective comfort, visual acuity, and lipid deposition in silicone hydrogel contact lens wearers. Thirty-one existing contact lens wearers were enrolled and fitted with two week planned replacement silicone hydrogel contact lenses (Acuvue® Oasys®) in a prospective, randomized, paired-eye, investigator-masked trial. A phospholipid liposomal spray (Tears Again®) was applied to one eye (randomized) four times daily for two weeks. LogMAR high contrast visual acuity (VA), low contrast glare acuity (LCGA), non-invasive tear film break-up time (NIBUT), and lipid layer grade (LLG) were measured at baseline and day 14, in both treated and control eyes. Subjective comfort relative to baseline, and spectrofluorophotometric assessment of contact lens surface lipid deposition were also assessed on day 14. All measurements did not differ at baseline between treated and control eyes. Lipid layer thickness and tear film stability were increased on day 14 in treated eyes (all p<0.05), but not in control eyes (all p>0.05). A greater proportion of participants reported improved comfort in the treated eye relative to the control eye (p=0.002). There were no significant differences in visual acuity or in contact lens surface lipid deposition, between treated and control eyes, on day 14 (all p>0.05). The phospholipid liposomal spray increased tear film stability, lipid layer thickness and subjective comfort in silicone hydrogel contact lens wearers, without adversely affecting visual acuity or contact lens surface lipid deposition.

Preference pattern of low vision aids in glaucoma-redefining guidelines

Context: Low vision is an important aspect of glaucoma care which required custom based prescription of low vision devices (LVDs) to suit the needs of the patient. Purpose: To evaluate preference pattern of LVDs in glaucoma patients. Setting and Design: Retrospective hospital-based review in a low vision service of a tertiary eye care center. Materials and Methods: Criteria for low vision was defined as best corrected distance visual acuity < 20/80 in the better eye with logarithm of the minimum angle of resolution chart and/or near visual acuity < N10 binocularly with Bailey-Lovie word reading chart and/or visual field 20° or < 20° from the point of fixation. The data collected included age, gender, diagnosis, extent of visual field loss (mean deviation and central residual field of vision), type of visual disability, and the type of low vision aid preferred by the patients for daily routine use. Statistics: Multivariate logistic regression was used to assess the association between different variables influencing preference of particular LVD. Results: The mean age of patients (n = 67) was 50 ± 22.7 (9-83 years) which included 21 developmental (31%), 11 primary angle closure glaucoma (16%) and 35 primary open angle glaucoma (52%) with 61% older than 50 years. On multivariate regression, age < 30 years (β = −0.04, P = 0.005), color matching disability (β = 3.08, P = 0.002), glare (β = 2.04, P < 0.001) were significant influences for preference for electronic LVD. Conclusions: Younger patients < 30 years with glare and color contrast impairment may be prescribed electronic LVDs for optimal visual function.

Evaluating a New Suite of Luminance-Based Design Metrics for Predicting Human Visual Comfort in Offices with Daylight

ABSTRACTA new suite of visual comfort metrics is proposed and evaluated for their ability to explain the variability in subjective human responses in a mock private office environment with daylight. Participants (n = 48) rated visual comfort and preference factors, including 1488 discreet appraisals, and these subjective results were correlated against more than 2000 unique luminance-based metrics that were captured using high dynamic range photography techniques. Importantly, luminance-based metrics were more capable than illuminance-based metrics for fitting the range of human subjective responses to data from visual preference questionnaire items. No metrics based upon the entire scene ranked in the top 20 squared correlation coefficients, nor did any based upon illuminance or irradiance data, nor did any of the studied glare indices, luminance ratios, or contrast ratios. The standard deviation of window luminance was the metric that best fit human subjective responses to visual preference on seven of 12 questionnaire items (with r2 = 0.43). Luminance metrics calculated using the horizontal 40° band (a scene-independent mask) and the window area (a scene-dependent mask) represented the majority of the top 20 squared correlation coefficients for almost all subjective visual preference questionnaire items. The strongest multiple regression model was for the semantic differential rating (too dim–too bright) of the window wall (adjR2 = 0.49) and was built upon three variables; standard deviation of window luminance, the 50th percentile luminance value from the lower view window, and mean luminance of the 40° horizontal band.

Clinical study of customized aspherical intraocular lens implants.

To compare if there is an improvement in visual functions with age-related cataracts between patients receiving a aspherical intraocular lens (IOL) based on corneal wavefront aberration and patients randomly assigned lenses. A total of 124 eyes of 124 patients with age-related cataracts were placed in experimental group and a group receiving randomly assigned (RA) lenses. The experimental group was undergone Pentacam corneal spherical aberration measurement before surgery; the targeted range for residual total spherical aberration after surgery was set to 0-0.3 µm. Patients with a corneal spherical aberration <0.3 µm were implanted with a zero-spherical aberration advanced optics (AO) aspherical IOL and patients with an aberration ≥0.3 µm received a Tecnis Z9003 aspherical lens in experimental group. RA patients were randomly implanted with an AO lens or a Tecnis Z9003 lens. Three months after surgery total spherical aberration, photopic/mesopic contrast sensitivities, photopic/mesopic with glare contrast sensitivities, and logMAR vision were measured. Statistical analysis on logMAR vision showed no significant difference between two groups (P=0.413). The post-surgical total spherical aberration was 0.126±0.097 µm and 0.152±0.151 µm in the experimental and RA groups, respectively (P=0.12). The mesopic contrast sensitivities at spatial frequencies of 6, 12 and 18 c/d in the experimental group were significantly higher than of the RA group (P=0.00; P=0.04; P=0.02). The mesopic with glare contrast sensitivity in the experimental group at a spatial frequency of 18 c/d was also significantly higher vs the RA group (P=0.01). Pre-surgical corneal spherical aberration measurement in cataract patients followed by customized selection of aspherical IOL implants improved mesopic contrast sensitivities at high spatial frequencies, and thus is a superior strategy compared to the random selection of aspherical IOL implants.

The correlation between retinal sensitivity assessed by microperimetry and contrast sensitivity in diabetic macular oedema

AimTo investigate the relationship between contrast sensitivity (CS) and retinal sensitivity (RS) assessed by microperimetry (MP) in diabetic retinopathy (DR) with clinically significant macular oedema (CSME).MethodsA retrospective study was performed...

Low vision rehabilitation : skills for occupational therapists

Many older people referred to occupational therapy may experience sight loss, yet, in the presence of other disability, it is commonly overlooked by health professionals (Horowitz 2004). Sight loss can result in significant difficulty with activities of daily living (Dahlin Ivanoff et al 1998) and can be very challenging, particularly for older people who also experience other agerelated disability (Colenbrander & Fletcher, 1995). Low vision rehabilitation includes relatively simple techniques that, if used correctly, can enable the individual to make best use of remaining vision. Incorporating low vision rehabilitation techniques into occupational therapy can enable clients to perform occupations and enhance quality of life (Scheiman et al 2006). Workshop outline: Specific approaches used in low vision rehabilitation will be explored, including: • an introduction to low vision aids; • correct use and ergonomic positioning of low vision aids; • task lighting; • eccentric fixation training, a technique for central vision loss; • strategies to help homonymous hemianopia and additional cognitive or perceptual complications including visual neglect and visual overload; • management of disability glare and/or poor contrast sensitivity. Workshop outcomes: This workshop, jointly facilitated by a low vision therapist and an occupational therapist, will provide both knowledge and practical skills. These can be used to augment current practice, enable appropriate early referral to specific services if appropriate and can reduce the risk of the myriad negative outcomes associated with sight loss for older people (Scheiman et al 2006).

Relationship between absorptive lenses and contrast sensitivity in healthy young subjects with glare under photopic- and mesopic-vision conditions

We investigated the effect of absorptive lenses on contrast sensitivity under photopic- and mesopic-visions with glare, from the viewpoint of luminous transmittance (LT) and spectral transmittance. The subjects were 24 healthy volunteers. Log contrast sensitivity (logCS) under two luminance conditions with glare was measured with a contrast glare test device. Binocular logCSs with absorptive lenses were compared with those without absorptive lenses (control condition). Furthermore, to investigate the effect of spectral transmittance, we calculated the ratio of stimulus quantity and the correlation between this ratio and logCS. Compared with that in the control, logCS was hardly affected in the case of high-luminous-transmittance absorptive lenses under binocular visions with glare. Middle- and long-wavelength lights effectively contribute to contrast sensitivity under photopic-vision and lights at each wavelength showed almost the same coefficients of correlation under mesopic-vision. Previous studies suggested that absorptive lenses provide users with protection against harmful radiation and glare. Our present results suggested that short-wavelength and high-LT absorptive lenses are particularly useful in daylight.

Multizentrische Studie zur Fahreignungsbegutachtung von LASIK- und Orthokeratologie-Patienten im Vergleich zu konventionell korrigierten Personen

Corneal optical zone induced by LASIK and orthokeratology (Ortho-K) treatment modifies the refraction of the incoming light bundle in its border area in situations of dawn and darkness. Considering the legal regulations of the driver's license and the recommendations of the German Society of Ophthalmology (DOG) and the American Academy of Ophthalmology (AAO), the vision for driving suitability of ortho-K patients is tested and compared with that of LASIK patients and a reference group (juvenile: < 30 years, adult: > 40 years) under different criterions. The examination of the visual acuity, contrast sensitivity under mesopic conditions and glare contrast sensitivity are main topics of the study. This multicentre retrospective study includes 333 eyes of 167 subjects. 65 subjects were habitual wearers of reverse-geometry contact lenses, 60 subjects were treated by LASIK. 42 subjects use glasses, contact lenses or none of them. The follow-up time was 22.8 ± 11.9 months. The measurement of the visual acuity was based on DIN Standard 58220 part 3 and the ISO Standard 8596. The Mesotest II (Oculus Inc.) was used for testing contrast sensitivity under mesopic conditions and glare contrast sensitivity. Detecting the personal evaluation of vision and satisfaction, subjects were instructed to complete a questionnaire (NEI-RQL-42). Relating to the legal requirements in Germany, sufficient visual acuity was found in 76.7 % of the LASIK group, in 73.9 % of the Ortho-K users and in 85.7 % of the reference group (72.7 % in the adult group, 100 % in the juvenile group). Considering the DOG recommendations under inclusion of mesopic vision and glare sensitivity, 71.7 % of the LASIK subjects and 95.7 % of the Ortho-K subjects are suitable for driving a motor vehicle of the German classes A, A1, B, BE, M, S, L and T. With regard to the legal situation in the USA, 100 % of the Ortho-K users, 93.2 % of the LASIK group, 86.4 % of the adult reference group and 100 % of the juvenile reference group are fit to drive. The evaluation of the subjective questionnaire showed very high ratings in the Ortho-K (mean 85 of 100 points) and the LASIK (mean 86 of 100 points) group with no statistically significant differences. Considering the legal regulations, the volume of the subjects of Ortho-K and LASIK showed no significant difference of individuals considered fit to drive in comparison to a reference group. Neither LASIK nor Ortho-K patients have any restriction in the ability to drive a vehicle. The requirements of the DOG with regard to contrast sensitivity under mesopic conditions and glare contrast sensitivity for driving a vehicle are better fulfilled in the Ortho-K group compared to the group of LASIK patients. According to the DOG recommendations there are fewer subjects that are suitable for driving a motor vehicle as in the reference group. This fact must be discussed preoperatively.

Efficacy of vision restoration therapy after optic neuritis (VISION study): study protocol for a randomized controlled trial

BackgroundOptic neuritis is a frequent manifestation of multiple sclerosis. Visual deficits range from a minor impairment of visual functions through to complete loss of vision. Although many patients recover almost completely, roughly 35% of patients remain visually impaired for years, and therapeutic options for those patients hardly exist. Vision restoration therapy is a software-based visual training program that has been shown to improve visual deficits after pre- and postchiasmatic injury. The aim of this pilot study is to evaluate whether residual visual deficits after past or recent optic neuritis can be reduced by means of vision restoration therapy.Methods/designA randomized, controlled, patient- and observer-blinded clinical pilot study (VISION study) was designed to evaluate the efficacy of vision restoration therapy in optic neuritis patients. Eighty patients with a residual visual deficit after optic neuritis (visual acuity ≤0.7 and/or scotoma) will be stratified according to the time of optic neuritis onset (manifestation more than 12 months ago (40 patients, fixed deficit) versus manifestation 2 to 6 months ago (40 patients, recent optic neuritis)), and randomized into vision restoration therapy arm or saccadic training arm (control intervention). Patients will be instructed to complete a computer-based visual training for approximately 30 minutes each day for a period of 6 months. Patients and evaluators remain blinded to the treatment allocation throughout the study. All endpoints will be analyzed and P-values < 0.05 will be considered statistically significant. The primary outcome parameter will be the expansion of the visual field after 3 and 6 months of treatment as determined by static visual field perimetry and high resolution perimetry. Secondary outcome variables will include visual acuity at both low and high contrast, glare contrast sensitivity, visually evoked potentials, optical coherence tomography and other functional tests of the visual system, alertness, health-related quality of life, fatigue, and depression.DiscussionIf vision restoration therapy is shown to improve visual function after optic neuritis, this method might be a first therapeutic option for patients with incomplete recovery from optic neuritis.Trial registrationNCT01274702