qCSF Method Research Articles

Contrast Sensitivity Function: A More Sensitive Index for Assessing Protective Effects of the Cilioretinal Artery on Macular Function in High Myopia.

To assess the benefits of the cilioretinal artery on macular function in high myopia using the quantitative contrast sensitivity function (qCSF) method. This cross-sectional study was conducted at the Eye and Ear, Nose, and Throat Hospital of Fudan University. In total, 137 highly myopic patients (with axial length [AL] ≥ 26.00 mm) were enrolled and divided into cilioretinal artery absent and present groups based on their fundus photographs. One eye in each patient was randomly selected. Choroid thickness was measured using macular optical coherence tomography. The best-corrected visual acuity (BCVA) was evaluated by Early Treatment Diabetic Retinopathy Study charts, and the area under the log CSF (AULCSF), CSF acuity, and CS at six spatial frequencies were evaluated with the qCSF method. Although no significant BCVA difference was found between the cilioretinal artery absent (97 patients) and present (40 patients) groups, choroid thickness, AULCSF, CSF acuity, and CSF at low and intermediate spatial frequencies (1-6 cycles per degree) were all significantly higher in the cilioretinal artery present group than in the absent group (all P < 0.05). In addition, eyes with temporal cilioretinal arteries exhibited significantly higher AULCSF, CSF acuity, and CSFs at 3 and 6 cycles per degree (all P < 0.05) than those with a nasal one (all P < 0.05). Multivariate analysis showed that better AULCSF was associated with the presence of cilioretinal artery and the interaction of AL and choroid thickness. The cilioretinal artery may associate with the larger choroid thickness in highly myopic eyes and may play a role in preserving qCSF outcomes, which are more sensitive than chart-based acuity tests.

Tolerance to lens tilt and decentration of two multifocal intraocular lenses: using the quick contrast sensitivity function method

BackgroundQuick contrast sensitivity function (qCSF) method is an advanced quick method for contrast sensitivity function (CSF) evaluation. This study evaluated the contrast sensitivity (CS) of eyes undergoing cataract surgery with multifocal intraocular lens (IOL) implantation and its tolerance to IOL tilt and IOL decentration using the qCSF method.MethodsPatients undergoing uneventful phacoemulsification and a trifocal IOL (Zeiss AT LISA tri 839MP, Carl Zeiss, Germany) or an extended depth-of-focus (EDOF) IOL (Tecnis Symfony ZXR00, Johnson & Johnsons, USA) implantation were included. Monocular contrast sensitivity was measured using the qCSF method at one month post-surgery. IOL tilt and decentration were measured using an optical aberrometer (OPD-Scan III, NIDEK, Japan).ResultsSeventy-two patients/eyes with the 839MP IOL and 64 patients/eyes with the ZXR00 IOL were included. Area under the log CSF (AULCSF) and CS acuity did not differ significantly between the two groups. The ZXR00 IOL group showed better CS at 1 cpd (1.137 ± 0.164 vs. 1.030 ± 0.183 logCS) and 1.5 cpd (1.163 ± 0.163 vs. 1.071 ± 0.161 logCS), while the 839MP IOL group had better CS at 6 cpd (0.855 ± 0.187 vs. 0.735 ± 0.363 logCS). In the 839MP IOL group, all CSF metrics were negatively correlated with IOL tilt (all P < 0.05), while in the ZXR00 IOL group, the CS at 3 cpd had no significant correlation with IOL tilt (P > 0.05). Among myopic eyes, fewer CSF metrics were negatively correlated with IOL tilt in the ZXR00 IOL group than in the 839MP IOL group. No significant correlation was found between CSF metrics and IOL decentration.ConclusionsThe ZXR00 and the 839MP IOL groups presented comparable CSF. CS was negatively correlated with IOL tilt, instead of decentration in multifocal IOLs, particularly among myopic eyes. The ZXR00 IOL had better tolerance to IOL tilt in myopic eyes.

Structure-function association between contrast sensitivity and retinal thickness (total, regional, and individual retinal layer) in patients with idiopathic epiretinal membrane.

To investigate structure-function associations between retinal thickness, visual acuity (VA), and contrast sensitivity (CS), using the quantitative contrast sensitivity function (qCSF) method in patients with idiopathic epiretinal membrane (ERM). Retrospective, cross-sectional observational study. Patients with a diagnosis of idiopathic ERM were included. Patients underwent complete ophthalmic examination, spectral-domain optical coherence tomography imaging (SD-OCT) (SPECTRALIS® Heidelberg), and CS testing using the qCSF method. Outcomes included area under the log CSF (AULCSF), contrast acuity (CA), and CS thresholds at 1, 1.5, 3, 6, 12, and 18 cycles per degree (cpd). A total of 102 eyes of 79 patients were included. Comparing standardized regression coefficients, retinal thickness in most ETDRS sectors was associated with larger reductions in AULCSF, CA, and CS thresholds at 3 and 6cpd than those in logMAR VA. These differences in effect on VA and CS metrics were more pronounced in the central subfield and inner ETDRS sectors. Among the retinal layers, increased INL thickness had the most detrimental effect on visual function, being significantly associated with reductions in logMAR VA, AULCSF, CA, and CS thresholds at 3 and 6cpd (all p < .01), as well as at 1.5 and 12cpd (p < .05). Retinal thickness seems to be associated with larger reductions in contrast sensitivity than VA in patients with ERM. Measured with the qCSF method, contrast sensitivity may serve as a valuable adjunct visual function metric for patients with ERM.

Contrast Sensitivity Is Associated With Chorioretinal Thickness and Vascular Density of Eyes in Simple Early-Stage High Myopia.

ObjectiveTo evaluate the contrast sensitivity function (CSF), chorioretinal thickness and vascular density as well as their relationships in subjects with simple early-stage high myopia.MethodsEighty-one young subjects were enrolled in this study. They were categorized into the simple high myopia group (sHM, n = 51) and the low-moderate myopia group (control group, n = 30). Monocular CSF under best correction was measured with the qCSF method. Retinal superficial and deep vascular density, inner and outer retinal thickness and choroidal thickness were measured using optical coherence tomography angiography.ResultsThe area under log CSF (AULCSF) and cutoff spatial frequency (Cutoff SF) of the sHM group were significantly reduced compared to those of the control group (P = 0.003 and P < 0.001, respectively). The parafoveal and perifoveal retinal thickness, deep vascular density and choroidal thickness were also significantly reduced in the sHM group (all P < 0.05). Multiple regression analysis revealed that AULCSF was significantly correlated with retinal deep vascular density, outer retinal thickness in the parafoveal and perifoveal areas (all P < 0.05).ConclusionCompared to low to moderate myopic eyes, patients with simple high myopia have thinner retinal and choroidal thickness, lower retinal vascular density, and reduced contrast sensitivity. Moreover, the CSF was correlated with the measures of chorioretinal structure and vasculature. The results suggest that the CSF is a sensitive functional endpoint in simple early-stage high myopia.

Hierarchical Bayesian modeling of contrast sensitivity functions in a within-subject design.

Recent development of the quick contrast sensitivity function (qCSF) method has made it possible to obtain accurate, precise, and efficient contrast sensitivity function (CSF) assessment. To improve statistical inference on CSF changes in a within-subject design, we developed a hierarchical Bayesian model (HBM) to compute the joint distribution of CSF parameters and hyperparameters at test, subject, and population levels, utilizing information within- and between-subjects and experimental conditions. We evaluated the performance of the HBM relative to a non-hierarchical Bayesian inference procedure (BIP) on an existing CSF dataset of 112 subjects obtained with the qCSF method in three luminance conditions (Hou, Lesmes, Kim, Gu, Pitt, Myung, & Lu, 2016). We found that the average d′s of the area under log CSF (AULCSF) and CSF parameters between pairs of luminance conditions at the test-level from the HBM were 33.5% and 103.3% greater than those from the BIP analysis of AULCSF. The increased d′ resulted in greater statistical differences between experimental conditions across subjects. In addition, simulations showed that the HBM generated accurate and precise CSF parameter estimates. These results have strong implications for the application of HBM in clinical trials and patient care.

Contrast sensitivity function in patients with macular disease and good visual acuity

IntroductionContrast sensitivity function (CSF) may better estimate a patient’s visual function compared with visual acuity (VA). Our study evaluates the quick CSF (qCSF) method to measure visual function in eyes...

Measuring the Contrast Sensitivity Function Using the qCSF Method With 10 Digits.

PurposeThe Bayesian adaptive quick contrast sensitivity function (qCSF) method with a 10-letter identification task provides an efficient CSF assessment. However, large populations are unfamiliar with letters and cannot benefit from this test. To overcome the barrier, we conducted this study.MethodA new font for digits (0∼9) was created. The digits were then filtered with a raised cosine filter, rescaled to different sizes to cover spatial frequencies from 0.5 to 16 cycles per degree (cpd), and used as stimuli in a 10-alternative forced choice (10AFC) digit identification task. With the 10AFC digit identification task, the CSFs of five young and five old observers were measured using the qCSF and Psi methods. The estimates from the latter served as reference.ResultsThe new digit font showed significantly improved similarity structure, Levene's test, F(1, 88) = 6.36, P = 0.014. With the 10-digit identification task, the CSFs obtained with the qCSF method matched well with those obtained with the Psi method (root mean square error [RMSE] = 0.053 log10 units). With approximately 30 trials, the precision of the qCSF method reached 0.1 log10 units. With approximately 75 trials, the precision of the CSFs obtained with the qCSF was comparable to that of the CSFs measured by the Psi method in 150 trials.ConclusionsThe qCSF with the 10 digit identification task is validated for both young and old observers.Translational RelevanceThe qCSF method with the 10-digit identification task provides an efficient and precise CSF test especially for people who are unfamiliar with letters.

Quick contrast sensitivity measurements in the periphery.

Measuring the contrast sensitivity function (CSF) in the periphery of the eye is complicated. The lengthy measurement time precludes all but the most determined subjects. The aim of this study was to implement and evaluate a faster routine based on the quick CSF method (qCSF) but adapted to work in the periphery. Additionally, normative data is presented on neurally limited peripheral CSFs. A peripheral qCSF measurement using 100 trials can be performed in 3 min. The precision and accuracy were tested for three subjects under different conditions (number of trials, peripheral angles, and optical corrections). The precision for estimates of contrast sensitivity at individual spatial frequencies was 0.07 log units when three qCSF measurements of 100 trials each were averaged. Accuracy was estimated by comparing the qCSF results with a more traditional measure of CSF. Average accuracy was 0.08 log units with no systematic error. In the second part of the study, we collected three CSFs of 100 trials for six persons in the 20° nasal, temporal, inferior, and superior visual fields. The measurements were performed in an adaptive optics system running in a continuous closed loop. The Tukey HSD test showed significant differences (p < 0.05) between all fields except between the nasal and the temporal fields. Contrast sensitivity was higher in the horizontal fields, and the inferior field was better than the superior. This modified qCSF method decreases the measurement time significantly and allows otherwise unfeasible studies of the peripheral CSF.

QCSF in Clinical Application: Efficient Characterization and Classification of Contrast Sensitivity Functions in Amblyopia

The qCSF method is a novel procedure for rapid measurement of spatial contrast sensitivity functions (CSFs). It combines Bayesian adaptive inference with a trial-to-trial information gain strategy, to directly estimate four parameters defining the observer's CSF. In the present study, the suitability of the qCSF method for clinical application was examined. The qCSF method was applied to rapidly assess spatial CSFs in 10 normal and 8 amblyopic participants. The qCSF was evaluated for accuracy, precision, test-retest reliability, suitability of CSF model assumptions, and accuracy of amblyopia screening. qCSF estimates obtained with as few as 50 trials matched those obtained with 300 Ψ trials. The precision of qCSF estimates obtained with 120 and 130 trials, in normal subjects and amblyopes, matched the precision of 300 Ψ trials. For both groups and both methods, test-retest sensitivity estimates were well matched (all R > 0.94). The qCSF model assumptions were valid for 8 of 10 normal participants and all amblyopic participants. Measures of the area under log CSF (AULCSF) and the cutoff spatial frequency (cutSF) were lower in the amblyopia group; these differences were captured within 50 qCSF trials. Amblyopia was detected at an approximately 80% correct rate in 50 trials, when a logistic regression model was used with AULCSF and cutSF as predictors. The qCSF method is sufficiently rapid, accurate, and precise in measuring CSFs in normal and amblyopic persons. It has great potential for clinical practice.