Log Contrast Sensitivity Function Research Articles

Normal- and Low-Luminance Automated Quantitative Contrast Sensitivity Assessment in Eyes With Age-Related Macular Degeneration

To assess the effectiveness of an active learning approach to measuring the contrast sensitivity function (CSF) in patients with various degrees of dry age-related macular degeneration (AMD) under multiple luminance conditions. Cross-sectional study. Patients with AMD (26 intermediate AMD, 19 AMD with subretinal drusenoid deposits [SDD], 20 geographic atrophy [GA]) and 23 age-matched controls were tested with the Manifold Contrast Vision Meter (Adaptive Sensory Technology) and the qCSF algorithm, which applies active learning to estimate a model of the CSF's global shape. Testing was performed under conditions of standard and low luminance. For each AMD severity, the area under log CSF (AULCSF) and contrast sensitivities at individual spatial frequencies were calculated for analysis. Low-luminance deficits (LLDs) for visual acuity (VA) and AULCSF were calculated as the difference between standard and low luminance values. Progressive decreases in AULCSF were observed as disease severity increased. For standard luminance, pairwise comparisons revealed significant differences between control/intermediate AMD (P < .0005), control/SDD (P < .0005), control/GA (P < .0005), and intermediate AMD/GA (P < .005). Similarly, for low luminance, pairwise comparisons revealed significant differences between the controls and each disease group (all P < .0005), in addition to significant differences between intermediate AMD/SDD (P < .005), and intermediate AMD/GA (P < .005). No correlations were found between LLD VA and LLD AULCSF in any AMD groups. Contrast sensitivity measured via qCSF under both standard- and low-luminance conditions correlates with advancing stages of dry AMD. The interaction between luminance and contrast sensitivity appears to reflect a different aspect of visual function than the interaction between luminance and VA.

Visual Improvements after Perceptual Learning Transfer from Normoxia to Hypoxia

ABSTRACT Objective: This study aimed to evaluate vision improvement in hypoxia following normoxic perceptual learning. Background: Visual functions are important for flight safety. However, the potential of perceptual learning to compensate for hypoxic vision damage is unclear. Method: Seven observers enrolled in this study and were exposed to a hypoxic (11.5% O2) and a mesopic (3 cd/m2) environment. Visual acuity (VA) and contrast sensitivity function (CSF) were evaluated in normoxia and hypoxia before and after the 8 daily training sessions. All observers trained in a monocular sine-wave grating detection task near their individual cutoff spatial frequencies while breathing normoxic gas. Results: The contrast sensitivity (CS) at the trained spatial frequency, the area under the log CSF (AULCSF) and VA decreased in a hypoxic environment. Additionally, all visual performances (i.e., CS, AULCSF and VA), regardless of whether they were measured in the normoxic or hypoxic condition, improved following normoxic perceptual learning. The degree of visual improvement did not differ between normoxia and hypoxia, indicating that visual improvement is completely transferable from normoxia to hypoxia. Conclusions: Preliminary evidence suggests that visual improvement remains even under environmental changes, and perceptual learning may be a noninvasive way to compensate for vision decreases in hypoxia.

Effects of Intermediate-Tinted Lenses on Pistol Marksmanship and Visual Performance.

The standard issue clear or sun Military Combat Eye Protection (MCEP) is often inadequate in visually challenging training or combat environment. Intermediate-tinted lenses may offer a viable option for warfighters operating in dynamic visual conditions such as moving rapidly from bright sunny areas to darker building interiors in combat. Because the use of intermediate-tinted lenses has been delayed as a result of a potential negative impact on vision performance such as color perception, this investigation evaluated several commercially available intermediate-tinted lenses for operation performance during a U.S. military field training. Test lenses complied with all the requirements of the current MCEP except for the visible light transmittance (VLT) values that ranged between 32 and 62%. Study subjects consisted of 22 service members who attended a military Close Combat and Marksmanship training course in May 2019. Visual and pistol marksmanship performance of three intermediate-tinted lenses (Eye Safety Systems [ESS] Copper [32% VLT], Oakley Prizm TR45 [44% VLT], and ESS Bronze [62% VLT]) was compared to that of a standard issue MCEP, ESS Clear (90% VLT). Quick contrast sensitivity function test was used to assess quality vision (AULCSF, area under a log contrast sensitivity function) and visual acuity (CSF Acuity). Color vision was assessed by Cone Contrast Test. Pistol marksmanship (Bill Drill) was used for performance testing. A pre-survey inquired about MCEP use, and a MCEP survey during the pistol marksmanship testing inquired about lens performance and ranking. AULCSF and CSF Acuity were significantly affected by the lenses (general linear model, repeated measures, P < .05). Bonferroni post hoc test showed a significant reduction of binocular AULCSF from ESS Clear to Oakley Prizm TR45 (P = .003) and ESS Copper (P < .001) and a significant reduction in binocular CSF Acuity from ESS Clear to ESS Copper (P = .001). Color vision and pistol marksmanship performance were not significantly affected by wearing different lenses (P > .05). Subjectively, there were no statistically significant differences among study lenses in perceived "clarity of vision," "ability to clearly identify the target," or "overall performance" (Friedman test and Wilcoxon signed-rank post hoc test with Bonferroni adjustment, P > .017). Participants ranked Prizm TR45 (44% VLT) and ESS Bronze (62% VLT) lenses significantly more favorably than EES Clear (P = .001 and P = .009). Quality of vision and visual acuity decreased with darker lenses; however, the study lenses had insignificant impacts on pistol marksmanship and subjective acceptance. Our surveys indicated that Intermediate-tinted lenses were operationally acceptable and preferred over a standard issue MCEP. While more evaluations for color vision deficient subjects are needed, overall results suggest that commercially available intermediate-tinted lenses may be a viable option to enhance protection and performance in a visually dynamic combat environment.

A New Dichoptic Training Strategy Leads to Better Cooperation Between the Two Eyes in Amblyopia.

Recent clinical trials failed to endorse dichoptic training for amblyopia treatment. Here, we proposed an alternative training strategy that focused on reducing signal threshold contrast in the amblyopic eye under a constant and high noise contrast in the fellow eye (HNC), and compared it to a typical dichoptic strategy that aimed at increasing the tolerable noise contrast in the fellow eye (i.e., TNC strategy). We recruited 16 patients with amblyopia and divided them into two groups. Eight patients in Group 1 received the HNC training, while the other eight patients in Group 2 performed the TNC training first (Phase 1) and then crossed over to the HNC training (Phase 2). We measured contrast sensitivity functions (CSFs) separately in the amblyopic and fellow eyes when the untested eye viewed mean luminance (monocularly unmasked) or noise stimuli (dichoptically masked) before and after training at a particular frequency. The area under the log contrast sensitivity function (AULCSF) of masked and unmasked conditions, and dichoptic gain (the ratio of AULCSF of masked to unmasked condition) were calculated for each eye. We found that both dichoptic training paradigms substantially improved masked CSF, dichoptic gain, and visual acuity in the amblyopic eye. As opposed to the TNC paradigm, the HNC training produced stronger effects on masked CSFs, stereoacuity, dichoptic gain, and visual acuity in the amblyopic eye. Interestingly, the second-phase HNC training in Group 2 also induced further improvement in the masked contrast sensitivity and AULCSF in the amblyopic eye. We concluded that the HNC training strategy was more effective than the TNC training paradigm. Future design for dichoptic training should not only focus on increasing the tolerable noise contrast in the fellow eye but should also “nurture” the amblyopic eye under normal binocular viewing conditions and sustained interocular suppression.

Disorganisation of retinal inner layers is associated with reduced contrast sensitivity in retinal vein occlusion

Background/AimsTo determine if disorganisation of retinal inner layers (DRIL) is associated with reduced contrast sensitivity (CS) in patients with retinal vein occlusion (RVO) with a history of macular oedema (ME).MethodsProspective,...

Reduced Contrast Sensitivity Function in Central and Peripheral Vision by Disability Glare.

Various glares can decrease visual performance and cause discomfort, thus increasing drivers' risk for traffic accidents in real life. The current study aimed to systematically investigate glare sensitivity in the central and peripheral visual fields by measuring contrast sensitivity function (CSF) under nonglare, steady glare, and transient glare conditions. Nine observers with normal visual acuity in the dominant eye were enrolled. The CSF in central and peripheral vision (the 5° upper left visual field) was measured in a mesopic environment while the stimulus was displayed under three conditions: nonglare, steady glare, and transient glare. An orientation identification task was used to obtain the CSF. After the experiment, the observers were asked to report their level of discomfort in the presence of the glare. The area under the log CSF (AULCSF) and cut-off spatial frequency served as indicators of visual performance. In agreement with previous studies, both steady and transient glare reduced the AULCSF and cut-off frequency. However, the AULCSF and cut-off frequency were reduced more for central vision than for nearly peripheral vision. In addition, the extent of the decreases in the AULCSF and cut-off frequency was greater for steady glare than for transient glare; in contrast, more discomfort was associated with transient glare than steady glare.

Improvement in Contrast Sensitivity Function after Lacrimal Passage Intubation in Eyes with Epiphora

This prospective case series aimed to investigate the contrast sensitivity function before and after lacrimal passage intubation (LPI) in eyes with epiphora due to lacrimal passage obstruction. We included 58 eyes of 51 patients who underwent LPI for lacrimal passage obstruction. The best-corrected visual acuity (BCVA), contrast sensitivity function, and lower tear meniscus were compared before LPI and one month after lacrimal duct stent removal. The area under the log contrast sensitivity function (AULCSF) was calculated for the analyses. Lower tear meniscus was assessed using anterior segment optical coherence tomography. The BCVA was comparable (p = 0.61) before and after LPI, while AULCSF increased significantly after treatment (before LPI: 1.29 ± 0.17, after LPI: 1.37 ± 0.14, p < 0.0001). Treatment resulted in a significant increase in contrast sensitivity at all spatial frequencies, 3–18 cycles/degree (p < 0.01 for 3, p < 0.01 for 6, p < 0.0005 for 12, p < 0.05 for 18 cycles/degree). The lower tear meniscus parameters improved significantly after treatment (p < 0.005); however, no correlation between the changes in the tear meniscus and those of the AULCSF was found. The contrast sensitivity significantly improved after LPI in eyes with epiphora due to lacrimal passage obstruction.

Deterioration of contrast sensitivity in eyes with epiphora due to lacrimal passage obstruction.

Epiphora causes deterioration in contrast sensitivity in some eye diseases. This study was conducted to investigate contrast sensitivity in eyes with epiphora caused by lacrimal passage obstruction. This single-center, prospective case series enrolled 57 patients with unilateral lacrimal passage obstruction. The best-corrected visual acuity (BCVA), contrast sensitivity function, and lower tear meniscus of the affected and contralateral unaffected eyes were compared. The area under the log contrast sensitivity function (AULCSF) was calculated. The BCVA did not significantly differ between the affected and contralateral eyes, while the AULCSF was significantly lower in the affected eyes than that in the contralateral eyes (median 1.35, interquartile range 1.22-1.44 vs. median 1.36, interquartile range 1.28-1.46, P = 0.032). Lower tear meniscus parameters were significantly higher in the affected eyes than those in the contralateral eyes (P < 0.005). The contrast sensitivity function is significantly diminished in eyes with epiphora caused by lacrimal passage obstruction.

Impact of posterior vitreous detachment on contrast sensitivity in patients with multifocal intraocular lens.

To investigate posterior vitreous detachment (PVD) and pars plana vitrectomy (PPV) effects on contrast sensitivity function (CSF) in patients with a multifocal intraocular lens (MfIOL). This single-center prospective case-control study analyzed 27 patients with 43 consecutive eyes. Twenty patients with 36 consecutive eyes received MfIOL implantation with either ZLB00 or ZMB00. CSF was measured as the area under the log contrast sensitivity function (AULCSF) in the presence and absence of PVD (PVD+ group and PVD- group, respectively). Seven eyes associated with a symptomatic PVD and severe visual dissatisfaction after MfIOL implantation underwent PPV (symptomatic PVD+ group). CSF was measured prior to and after PPV. The mean AULCSF was significantly lower in the PVD+ group (1.5 ± 0.1) versus the PVD- group (1.7 ± 0.1, p < 0.0001). Major complaints in the symptomatic PVD+ group included floaters (n = 2) and blurry vision (n = 5). The preoperative AULCSF (1.4 ± 0.1) was significantly lower in the symptomatic PVD+ group versus the PVD- group (p < 0.0001) and PVD+ group (p = 0.02). The preoperative AULCSF in the symptomatic PVD+ group was significantly improved after PPV (1.4 vs. 1.7, respectively, p = 0.002). PVD significantly decreased CSF in patients with MfIOL. Patients with symptomatic PVD exhibited the greatest decrease in CSF, which was significantly improved after PPV. Measurement of CSF and careful assessment of PVD may be useful in determining the appropriateness of surgical intervention for improving visual performance and satisfaction in MfIOL patients with symptomatic PVD.

Associations between visual-related quality of life and monocular or binocular quick contrast sensitivity function in early cataract patients

Objective To assess the association between visual-related quality of life (QOL) and the severity of quick contrast sensitivity function (qCSF) defects in patients with early cataract. Methods A cross section design was performed.Ninety-two eyes of 46 patients with early cataract were enrolled in Zhongshan Ophthalmic Center from March to June in 2017.All subjects completed the Chinese version of the National Eye Institute Visual Function Questionnaire (NEI VFQ-25). The qCSF measurements were performed monocularly and binocularly while the patients wearing full spectacle correction spectacles.Rasch analysis was performed to obtain final NEI VFQ-25 scores.Best corrected visual acuity (BCVA)(LogMAR) was measured and the eye with the better or the worse visual acuity was defined accordingly.The correlation between the Rasch calibrated QOL composite scores and the qCSF measurements of the better eye, the worse eye and binoculus, including the area under Log contrast sensitivity function (AULCSF), qCSF under cut-off frequency and 1.0, 1.5, 3.0, 6.0, 12.0, 18.0 c/d were analyzed.This study protocol was approved by the Ethic Committee of Zhongshan Ophthalmic Center.This study complied with Declaration of Helsinki. Results The Rasch calibrated QOL composite score was 64.13±4.76.Significant negative correlations were found between composite scores of QOL and the BCVA of both the better or worse eye(the better eye: r=-0.386, P=0.008; the worse eye: r=-0.413, P=0.004). Significant positive correlations were found between the composite scores of QOL and the AULCSF of binoculus, the better and worse eye (binoculus: r=0.531, P<0.001; the better eye: r=0.524, P<0.001; the worse eye: r=0.711, P<0.001); Significant positive correlations were found between the composite scores of QOL and the qCSF under cut-off of binoculus, the better and worse eye (binoculus: r=0.504; the better eye: r=0.419; the worse eye: r=0.694, P<0.01). The composite scores of QOL was positively correlated with the qCSF under 1.5, 3.0, 6.0, 12.0 c/d of binoculus, the better and worse eye (binoculus: r=0.444, 0.544, 0.545, 0.493; all at P<0.05; the better eye: r=0.374, 0.506, 0.530, 0.431; all at P<0.05; the worse eye: r=0.513, 0.679, 0.710, 0.558; all at P<0.05). The composite scores of QOL was positively correlated with the qCSF under 1.0, 18.0 c/d of binoculus and the worse eye (1.0 c/d: r=0.296, 0.292; both at P<0.05; 18.0 c/d: r=0.386, 0.321; both at P<0.05). Conclusions The qCSF measurements can reflect visual function of patients with early cataract at different spatial frequencies.The qCSF measurements of binoculus, the better eye and the worse eye show significant correlations with the composite scores of QOL.The QOL of early cataract patients shows a strong dependency on the worse eye. Key words: Quick Contrast Sensitivity Function; Quality of life; Cataract

Vision Parameters Most Important to Functionality in Glaucoma.

PurposeTo determine the importance of various vision parameters to functionality in glaucoma.MethodsVision was measured using seven parameters: visual acuity (VA), contrast sensitivity (CS), integrated visual field (IVF), area under the log CS function (AULCSF), color vision, stereoacuity, and VA with noise (ViN). Likelihood ratio testing (LRT) determined if the full set of visual parameters significantly explained variability in 10 functional outcomes. For outcomes where the visual contribution was significant, dominance analysis determined the relative importance of the various visual parameters.ResultsThe analysis included 151 glaucoma patients. Mean age was 70 ± 6.8 years, and 47% were men. Significant visual contributions (LRT P < 0.05) were noted for glaucoma quality of life (GQL-15), reading speed, driving cessation, daily steps, and base of support while walking, but not for fear of falling, balance, gait velocity, stride velocity, and stride length while walking (LRT P > 0.05). The most important parameter (and percent contribution) to vision-explained variability were AULCSF for daily steps (45%), IVF for base of support (35%), VA for reading speed (34%), CS for GQL-15 (30%), and VA for driving cessation (26%).ConclusionsMeasures of visual ability are important for several aspects of quality of life and functionality. The most important vision parameter for functionality differs depending on the domain studied. Reading and driving were explained by VA and IVF sensitivity. On the other hand, GQL-15 and daily steps were more heavily influenced by CS and AULCSF, which are rarely performed clinically.

Quantitative evaluation of visual function in patients with cornea verticillata associated with Fabry disease.

To evaluate the visual function of patients with cornea verticillata associated with Fabry disease through quantitative evaluations of contrast sensitivity function and straylight. We enrolled 28 eyes of 14 patients with Fabry disease (mean age, 37.1 ± 17.2 years) and 20 eyes of 20 age-matched healthy controls. Comprehensive ophthalmological examinations were performed and contrast sensitivity and letter contrast sensitivity were measured for all patients, following which the area under the log contrast sensitivity function (AULCSF) was calculated. Straylight was quantified using a straylight metre. Furthermore, subgroup analysis was performed according to the whorl-like pattern of cornea verticillata (mild and typical groups). All 28 eyes showed cornea verticillata. Visual acuity and letter contrast sensitivity values were the same for normal eyes and those with Fabry disease. AULCSF differed by 0.15 log[s] between the eyes with Fabry disease and the control eyes (p<0.001), while straylight differed by 0.45 log[s] between the two groups (p<0.001). Subgroup analysis based on the whorl-like pattern of cornea verticillata showed that AULCSF and straylight differed by 0.11 log[s] and 0.08 log[s], respectively, between the typical and mild groups (p=0.036 and p=0.147, respectively). Although cornea verticillata associated with Fabry disease does not affect the visual acuity and letter contrast sensitivity, more comprehensive testing of visual function by the inclusion of straylight and grating contrast sensitivity measurements shows clear functional deficits in these patients.

Effects of Myopic Orthokeratology on Visual Performance and Optical Quality.

To analyze the changes in visual performance and optical quality after orthokeratology (ortho-k) treatment and its correlation with the magnitude of lens decentration and the diameter of treatment zone (TxZ). A prospective study was conducted in 27 eyes of 27 patients wearing ortho-k contact lens. Area under log contrast sensitivity function (AULCSF), modulation transfer function cutoff values (MTFcutoff), Strehl ratio (SR), and objective scattering index (OSI) were measured and compared before and 1 month after ortho-k lens treatment. Refractive sphere, astigmatism, and diameter and decentration of TxZ were tested against the change in AULCSF, MTFcutoff, SR, and OSI after ortho-k treatment in stepwise multiple linear regression models. Objective scattering index significantly increased and AULCSF, MTFcutoff, and SR significantly decreased after ortho-k lens wear (all P<0.001). The mean TxZ diameter was 3.61±0.26 mm, and the mean magnitude of TxZ decentration was 0.60±0.16 mm. The amount of lens decentration significantly correlated with the change in AULCSF and MTFcutoff (P=0.027 and P=0.005, respectively). The diameter of TxZ significantly correlated with the change in MTFcutoff and SR (P=0.005 and P=0.024, respectively). Visual and optical quality decreases after ortho-k treatment, which can be alleviated by a larger TxZ diameter and a smaller lens decentration.

Effects of astigmatic defocus on binocular contrast sensitivity.

PurposeTo determine the effects of astigmatism on contrast sensitivity (CS).MethodsEighteen normal volunteers (30.5 ± 6.0 [mean ± SD] years) were recruited. After correcting each refractive error by spectacles, against-the-rule (ATR) or with-the-rule (WTR) astigmatism of +1.00, +2.00 and +3.00 D was intentionally produced in both eyes, and then binocular CS was measured. The cylindrical addition of different powers (+1.00–+3.00 D) was compensated with spherical lenses so that the spherical equivalent refraction became zero in each eye. Subsequently, the above cylindrical addition was monocularly induced, and binocular CS was measured again. The relation between CS and astigmatic power, axis, and monocular or binocular astigmatism was investigated.ResultsWith binocular ATR and WTR astigmatism, increases in astigmatic power significantly correlated with decreases in the area under the log contrast sensitivity function (AULCSF). With monocular astigmatic defocus, astigmatic power addition did not affect AULCSF. With binocular astigmatic defocus of high-power (+2.00 and +3.00 D), ATR astigmatism deteriorated AULCSF more than WTR astigmatism. In a comparison between binocular and monocular astigmatic defocus, CS was significantly worse with binocular astigmatic defocus than with monocular astigmatic defocus at higher spatial frequencies regardless of astigmatic power.ConclusionsBinocular astigmatic defocus deteriorates CS depending on the amount of astigmatic power. ATR astigmatism reduces CS more than WTR astigmatism dose. In addition, binocular astigmatic defocus affects CS more severely than monocular astigmatic defocus especially at high spatial frequencies.

Predicting Visual Disability in Glaucoma With Combinations of Vision Measures.

PurposeWe characterized vision in glaucoma using seven visual measures, with the goals of determining the dimensionality of vision, and how many and which visual measures best model activity limitation.MethodsWe analyzed cross-sectional data from 150 older adults with glaucoma, collecting seven visual measures: integrated visual field (VF) sensitivity, visual acuity, contrast sensitivity (CS), area under the log CS function, color vision, stereoacuity, and visual acuity with noise. Principal component analysis was used to examine the dimensionality of vision. Multivariable regression models using one, two, or three vision tests (and nonvisual predictors) were compared to determine which was best associated with Rasch-analyzed Glaucoma Quality of Life-15 (GQL-15) person measure scores.ResultsThe participants had a mean age of 70.2 and IVF sensitivity of 26.6 dB, suggesting mild-to-moderate glaucoma. All seven vision measures loaded similarly onto the first principal component (eigenvectors, 0.220–0.442), which explained 56.9% of the variance in vision scores. In models for GQL scores, the maximum adjusted-R2 values obtained were 0.263, 0.296, and 0.301 when using one, two, and three vision tests in the models, respectively, though several models in each category had similar adjusted-R2 values. All three of the best-performing models contained CS.ConclusionsVision in glaucoma is a multidimensional construct that can be described by several variably-correlated vision measures. Measuring more than two vision tests does not substantially improve models for activity limitation.Translational RelevanceA sufficient description of disability in glaucoma can be obtained using one to two vision tests, especially VF and CS.

New Precision Metrics for Contrast Sensitivity Testing.

Visual sensitivity is comprehensively described by the contrast sensitivity function (CSF), but current routine clinical care does not include its assessment because of the time-consuming need to estimate thresholds for a large number of spatial frequencies. The quick CSF method, however, dramatically reduces testing times by using a Bayesian information maximization rule. We evaluate the test-retest variability of a tablet-based quick CSF implementation in a study with 100 subjects who repeatedly assessed their vision with and without optical correction. We first discuss two commonly used measures of repeatability, intraclass correlation and the Bland-Altman Coefficient of Repeatability, and show that they are vulnerable to artifacts. Instead, we propose to formulate precision as an information retrieval task: from all repeat test scores, can we retrieve a certain individual based on their first test score? We then use rank-based analyses such as mean average precision as a better measure to compare different test metrics, and show that the highest test-retest precision is achieved using a summary statistic, the area under the log CSF (AULCSF). This demonstrates the benefit of assessment of the whole CSF compared to sensitivity at individual spatial frequencies only. AULCSF also yields best discrimination performance (99.2%) between measurements that were taken with and without glasses, respectively, even better than CSF Acuity. The tablet-based quick CSF thus enables the rapid and reliable home monitoring of visual function, which has the potential to improve early diagnosis and treatment of ophthalmic pathologies such as diabetic retinopathy or age-related macular degeneration.

The Effect of Ocular Surface Regularity on Contrast Sensitivity and Straylight in Dry Eye.

To investigate the association between visual function and ocular surface regularity in dry eye. We enrolled 52 eyes of 52 dry eye patients (34 dry eyes with superficial punctate keratopathy [SPK] in the central corneal region [central SPK] and 18 dry eyes without central SPK) and 20 eyes of 20 normal control subjects. All eyes had a best-corrected distance visual acuity better than 20/20. We measured two indices of contrast sensitivity function under photopic conditions: contrast sensitivity and letter contrast sensitivity. The area under the log contrast sensitivity function (AULCSF) was calculated from the obtained contrast sensitivity data. Straylight was quantified using a straylight meter. Dry eyes with central SPK had significantly decreased contrast sensitivity function, including AULCSF and letter contrast sensitivity than those without central SPK and normal eyes (P < 0.05 for each). While the straylight values in both dry eye groups did not differ, straylight values were greater than those in normal eyes (P < 0.05 for both). In dry eye, the AULCSF and letter contrast sensitivity negatively correlated with the central SPK score (R = -0.485, P < 0.001, and R = -0.541, P < 0.001, respectively). In dry eye, reduced contrast sensitivity in part results from central SPK overlying the optical zone and the increased straylight results from tear film instability rather than central SPK.

Factors influencing contrast sensitivity function in myopic eyes.

PurposeTo evaluate the factors affecting the area under the log contrast sensitivity function (AULCSF) in healthy myopic eyes.MethodsWe retrospectively examined 201 eyes of 201 consecutive subjects (age, 31.8±7.4 years (mean ± standard deviation)) with myopic refractive errors of −1.25 to −8.25 diopters (D). From the contrast sensitivity data, the area under the log contrast sensitivity function (AULCSF) was calculated. Stepwise multiple regression analysis was used to assess the factors affecting the AULCSF.ResultsThe mean AULSCF was 1.09±0.09 (0.89 to 1.55). Explanatory variables relevant to the AULCSF were, in order of influence, the objective scattering index (OSI) (p = 0.018, partial regression coefficient B = –0.032) and logMAR CDVA (p = 0.022, B = –0.209) (adjusted R2 = 0.231). No significant correlation was seen with other clinical factors such as gender, manifest refraction, pupil size, lens density, corneal HOAs, or ocular HOAs.ConclusionsAlthough the great majority of the variance remains unexplained, eyes with lower OSI and better CDVA are more predisposed to show higher contrast sensitivity function. These results indicate that not only CDVA but also intraocular forward scattering may play some role in predicting the contrast sensitivity function in myopic subjects.

Contrast sensitivity and foveal microstructure following vitrectomy for epiretinal membrane.

To evaluate contrast sensitivity (CS) in patients with epiretinal membrane (ERM) following vitrectomy and to investigate the relationship between CS and foveal microstructures with spectral-domain optical coherence tomography (SD-OCT). Thirty-one eyes of 31 patients with ERM were included. We examined CS with a CSV-1000E chart, a logMAR best-corrected visual acuity (BCVA), and foveal microstructure by using SD-OCT before and at 6 months after surgery. From the CS data, the area under the log contrast sensitivity function (AULCSF) was calculated. Based on the OCT images, we quantified the mean thickness of the ganglion cell layer (GCL), the inner nuclear layer (INL), and the outer retinal layer (outer nuclear layer and outer plexiform layer [ONL+OPL]). The status of the photoreceptor inner and outer segment junction (IS/OS) and external limiting membrane (ELM) was also evaluated. Vitrectomy significantly improved logMAR BCVA and AULCSF. Even in patients with poor improvement of visual acuity (changes in logMAR BCVA by surgery was ≤0.2), postoperative AULCSF significantly increased by treatment (P < 0.05). Postoperative AULCSF showed a significant correlation with preoperative (P < 0.05) and postoperative (P < 0.05) ONL+OPL thickness, whereas other parameters were not relevant. Postoperative logMAR BCVA significantly correlated with postoperative status of IS/OS (P < 0.05) and preoperative ONL+OPL thickness (P < 0.05). In patients with ERM, CS improved even though their visual acuity did not recover significantly by vitrectomy. CS was associated with the thickness of outer retinal layer.

Efficacy and safety of continuous full-time patching therapy initiated in pure anisometropic amblyopic children aged 8 to 14 years

To investigate the efficacy and safety of full-time patching therapy of anisometropic amblyopia in children aged 8-14 years. It was a prospective case series study.Forty-three patients with anisometropic amblyopia without strabismus (ranged from 8-14 years, mean 10.8 years) were included in this study. All of the patients received eye patching for the entire day, 29 days a month, during the first 3 months. Distance best corrected visual acuity in LogMAR units; cycloplegic refraction and contrast sensitivity function were performed on all the patients before treatment, at a month later of full-time patching therapy, and all recorded at 3 months later, and evaluation the spatial function with visual acuity, the area under the log contrast sensitivity function (AULCSF), the co-ordinates of the peak of the CSF (maximum sensitivity, Smax, and the spatial frequency at which it occurs, Frmax) and the cut-off spatial frequency. Difference among groups was evaluated by analysis of variance (One-Way ANOVA), and the Bonferroni test investigated the pairwise comparison of the groups. The degree of amblyopia and the D-value of binocular AULCSF of before full-cover treatment, after one month's and three months' full-cover treatment were -0.70 ± 0.30, -0.57 ± 0.29, -0.47 ± 0.28 and 0.78 ± 0.48, 0.63 ± 0.43, 0.53 ± 0.42, respectively, which showed statistically significant differences (F = 6.406, P < 0.01; F = 3.517, P = 0.028). The degree of amblyopia, the D-value of binocular AULCSF after three months' full-cover treatment had significant difference compared with those before full-cover treatment (P < 0.01; P = 0.02). There were statistically significant differences along with time in the best corrected visual acuity (BCVA) of the amblyopic eye, AULCSF and CutSF (F = 6.906, P < 0.01; F = 4.016, P = 0.02; F = 5.717, P < 0.01). The BCVA of the amblyopic eye, AULCSF and CutSF after three months' full-cover treatment had significant difference compared with those before full-cover treatment (P < 0.01; P = 0.028; P < 0.01). However, the BCVA, AULCSF of the normal eye, and Smax, Frmax of amblyopic eye showed no statistically significant differences among groups along with time (F = 0.243, P = 0.785; F = 0.265, P = 0.768; F = 0.949, P = 0.390; F = 2.934, P = 0.057). The present results show that continuous full-time patching in older children with anisometropic amblyopia improves visual acuity, and cut off spatial sensitivity with no serious complications. The use of continuous full-time patching in after-school children to improve amblyopia seems promising.