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

Towards the validation of quantitative contrast sensitivity as a clinical endpoint: correlations with vision-related quality of life in bilateral AMD

AIM

To investigate if active learning of contrast sensitivity (CS) in bilateral age-related macular degeneration (AMD) correlates better than visual acuity (VA) with vision-related quality of life (VRQoL) using factor analysis-calibrated National Eye Institute Visual Function Questionnaire-25 (NEI VFQ-25).

METHODS

Prospective cross-sectional observational study in 93 patients (186 eyes) with bilateral AMD. CS was measured in one eye at a time with the quantitative CS function (qCSF) method (Adaptive Sensory Technology). Same-day VRQoL was assessed with factor analysis-calibrated NEI VFQ-25 visual function and socioemotional scales. Mixed-effects multiple linear regression analyses evaluated the associations of the qCSF outcomes and VA with the NEI VFQ-25 scales. A subgroup analysis on patients with AMD with VA more than 20/25 in both eyes was performed.

RESULTS

Compared with VA, CS outcomes were associated with larger effect on both visual function scale (standardised beta coefficients (β*) for area under the logarithm of CSF (AULCSF) curve and CS thresholds at 1.5, 3 and 6 cycles per degree (cpd): β*=0.50, 0.48, 0.52, 0.46, all p<0.001, respectively, vs β*=-0.45 for VA, all p<0.001) and socioemotional scale (β* for AULCSF and CS threshold at 6 cpd: β*=0.44, 0.44 vs β*=-0.42 for VA, all p<0.001). In patients with AMD with VA more than 20/25 in both eyes (N=20), both VFQ-25 scales and all CS outcomes were significantly reduced.

CONCLUSIONS

qCSF-measured CS strongly correlates with patient-reported VRQoL in bilateral AMD, even stronger than VA does. This study further validates qCSF-measured CS as a promising functional endpoint for future clinical trials in AMD.

Quantitative Contrast Sensitivity Function and the Effect of Aging in Healthy Adult Eyes: A Normative Database

BACKGROUND AND OBJECTIVE

We sought to establish normative quantitative contrast sensitivity function (qCSF) values in healthy adult eyes and investigate the effect of age on qCSF.

PATIENTS AND METHODS

Healthy eyes underwent qCSF testing (adaptive sensory technology) and Snellen's visual acuity (VA). Descriptive statistics and mixed-effects multivariable linear regressions were evaluated.

RESULTS

A total of 334 eyes (290 patients) with median age 61 years (range 21 to 88) had qCSF values as follows: area under the log contrast sensitivity function curve: 1.18; contrast acuity: 1.32; contrast sensitivity (CS) at 1 cycle per degree (cpd): 1.32; CS at 1.5 cpd: 1.37; CS at 3 cpd: 1.38; CS at 6 cpd: 1.20; CS at 12 cpd: 0.69; CS at 18 cpd: 0.22. Linear reductions in qCSF values per decade of age ranged from -0.02 to -0.07 vs 0.01 for visual acuity (VA). Age had a greater effect on the majority of qCSF values than VA (beta standardized regression coefficient ranged from -0.309 to -0.141 for qCSF values vs 0.177 for VA).

CONCLUSIONS

We herein establish a normative database for qCSF and quantify the effect of age on qCSF values, adding evidence towards the validation of qCSF as a clinical endpoint. [Ophthalmic Surg Lasers Imaging Retina 2024;55:212-219.].

Associations of quantitative contrast sensitivity with wide-field swept-source optical coherence tomography angiography in retinal vein occlusion

PURPOSE

To investigate associations between contrast sensitivity (CS) and vascular metrics on wide-field swept-source optical coherence tomography angiography (WF-SS-OCTA) in patients with retinal vein occlusion (RVO).

METHODS

This prospectively recruited, cross-sectional observational study included RVO patients who underwent quantitative CS function (qCSF) testing and WF-SS-OCTA using 3 × 3, 6 × 6, and 12 × 12 mm angiograms on the same day. The study measured several qCSF outcomes and WF-SS-OCTA vascular metrics, including vessel density (VD), vessel skeletonized density (VSD), and foveal avascular zone (FAZ). The data were analyzed using multivariable regression analysis controlling for age and central subfield thickness (CST).

RESULTS

A total of 43 RVO eyes of 43 patients and 30 fellow eyes were included. In RVO eyes, multiple vascular metrics were associated with CS outcomes but not visual acuity (VA). On 12 × 12 images, CS thresholds at 1 cpd, 1.5 cpd, and 3 cpd were significantly associated with VD and VSD, but VA was not. When comparing standardized regression coefficients, we found that vascular metrics had a larger effect size on CS than on VA. For instance, the standardized beta coefficient for FAZ area and CS at 6 cpd (β* = - 0.46, p = 0.007) was larger than logMAR VA (β* = 0.40, p = 0.011).

CONCLUSION

Microvascular changes on WF-SS-OCTA in RVO had a larger effect size on CS than VA. This suggests CS may better reflect the microvascular changes of RVO compared to VA. qCSF-measured CS might be a valuable adjunct functional metric in evaluating RVO patients.

Test-retest repeatability and agreement of the quantitative contrast sensitivity function test: towards the validation of a new clinical endpoint

PURPOSE

The purpose of this study is to investigate test-retest reliability and agreement of the quantitative contrast sensitivity function test (qCSF) in the retina clinic.

METHODS

A total of 121 right eyes of 121 patients were tested and consecutively re-tested with qCSF in the retina clinic. Outcomes included area under the logarithm of contrast sensitivity function curve (AULCSF), contrast acuity, and contrast sensitivity thresholds at 1-18 cycles per degree (cpd). Test-retest means were compared with paired t-test, variability was compared with the Brown-Forsythe test, and intraclass correlation coefficient (ICC) and Bland Altman plots evaluated reliability and agreement.

RESULTS

Mean test-retest differences for all qCSF metrics ranged from 0.02 to 0.05 log units without statistically significant differences in variability. Standard deviations ranged from 0.08 to 0.14. Coefficients of repeatability ranged from 0.16 to 0.27 log units. ICC > 0.9 for all metrics except 1cpd (ICC = 0.84, all p < 0.001); AULCSF ICC = 0.971.

CONCLUSION

qCSF-measured contrast sensitivity shows great test-retest repeatability and agreement in the retina clinic.

Binocular visual function improvement after pars plana vitrectomy for epiretinal membrane

PURPOSE

To report binocular visual function changes after pars plana vitrectomy for epiretinal membrane (ERM) and the related outcomes.

METHODS

Twenty-three eyes of 23 patients operated on for ERM were included in a retrospective study. Clinical data, best-corrected visual acuity (BCVA), contrast sensitivity and binocular visual function were assessed pre- and 1 and 3 months post-operatively. Binocular visual function assessment included the evaluation of fusional amplitudes (i.e., vergences) by the synoptophore, far distance stereopsis using polarized glasses and near stereopsis using Randot and TNO tests. Central macular thickness (CMT) was measured on Spectral Domain - Optical Coherence Tomography.

RESULTS

Mean age of the patients was 67 years. Mean BCVA and contrast sensitivity significantly improved post-operatively at one (p = 0.0006 and p = 0.0022, respectively) and 3 months (p < 0.0001 and p < 0.0001, respectively), while CMT significantly decreased after 1-3 months (p < 0.0001 and p < 0.0001, respectively). Fusional amplitudes improved after 3 months (p < 0.0001). Far distance and near stereopsis significantly improved after 3 months (p < 0.0001 and p = 0.0007 for Randot test, and p < 0.0001 for TNO test, respectively).

CONCLUSIONS

Pars plana vitrectomy for ERM surgery leads to an improvement of monocular and binocular visual functions (i.e., binocular fusion, near and far distance stereopsis), within 3 months post-operatively.