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Previous pattern electroretinogram studies indicate reduced retinal contrast gain in patients with a major depressive disorder (MDD) which may contribute to alterations in visual perception. In line, psychophysical investigations reported elevated contrast thresholds in MDD. This study aims to gain insights into higher-level processing of visual information in MDD by evaluating contrast suppression. We examined contrast suppression of 21 MDD patients and 23 healthy controls (HC) using four different stimulus conditions (spatial frequencies 6.3 and 12.6 cpd at 30% and 60% background contrast) in a psychophysical test. Participants were instructed to adjust perceived contrasts between two vertical target patches, embedded in a horizontally or vertically oriented grid background. With finer stimulus gratings, MDD patients exhibited less contrast suppression compared to HC, particularly when the stimulus contrast was high (p = 0.006; MDD vs. HC =  - 45%). Contrast suppression in the HC group was significantly reduced for the coarse compared to the fine grating, while contrast suppression scores in MDD did not change with the spatial properties of the stimulus. The reduced contrast suppression in patients with MDD supports the hypothesis of altered dopaminergic neurotransmission and could be attributed to alterations in the retinal receptive fields or in dysfunctional adaptation mechanisms in depression., Competing Interests: Declarations Competing interests KN, SPH, MBa, DE, KR, SK, SM, MBe, EF: no conflict of interest. LTvE: Advisory boards, lectures, or travel grants within the last 3 years: Roche, Eli Lilly, Janssen-Cilag, Novartis, Shire, UCB, GSK, Servier, Janssen and Cyberonics. KD: Formerly: Steering Committee Neurosciences and speaker honoraria, Janssen-Cilag, within the last three years. Ethics approval and consent to participate The Ethics Committee of the University Medical Center Freiburg (Approval ID: 314/18) approved the study. All participants gave written informed consent to participate., (© 2024. The Author(s).)

Contrast sensitivity, the amount of contrast required to discriminate an object, depends on spatial frequency (SF). The contrast sensitivity function (CSF) peaks at intermediate SFs and drops at other SFs. The CSF varies from foveal to peripheral vision, but only a couple of studies have assessed how the CSF changes with polar angle of the visual field. For many visual dimensions, sensitivity is better along the horizontal than the vertical meridian and at the lower than the upper vertical meridian, yielding polar angle asymmetries. Here, for the first time, to our knowledge, we investigate CSF attributes around polar angle at both group and individual levels and examine the relations in CSFs across locations and individual observers. To do so, we used hierarchical Bayesian modeling, which enables precise estimation of CSF parameters. At the group level, maximum contrast sensitivity and the SF at which the sensitivity peaks are higher at the horizontal than vertical meridian and at the lower than the upper vertical meridian. By analyzing the covariance across observers (n = 28), we found that, at the individual level, CSF attributes (e.g., maximum sensitivity) across locations are highly correlated. This correlation indicates that, although the CSFs differ across locations, the CSF at one location is predictive of that at another location. Within each location, the CSF attributes covary, indicating that CSFs across individuals vary in a consistent manner (e.g., as maximum sensitivity increases, so does the corresponding SF), but more so at the horizontal than the vertical meridian locations. These results show similarities and uncover some critical polar angle differences across locations and individuals, suggesting that the CSF should not be generalized across isoeccentric locations around the visual field.

Much progress has been made in understanding how the brain combines signals from the two eyes. However, most of this work has involved achromatic (black and white) stimuli, and it is not clear if the same processes apply in color-sensitive pathways. In our first experiment, we measured contrast discrimination ("dipper") functions for four key ocular configurations (monocular, binocular, half-binocular, and dichoptic), for achromatic, isoluminant L-M and isoluminant S-(L+M) sine-wave grating stimuli (L: long-, M: medium-, S: short-wavelength). We find a similar pattern of results across stimuli, implying equivalently strong interocular suppression within each pathway. Our second experiment measured dichoptic masking within and between pathways using the method of constant stimuli. Masking was strongest within-pathway and weakest between S-(L+M) and achromatic mechanisms. Finally, we repeated the dipper experiment using temporal luminance modulations, which produced slightly weaker interocular suppression than for spatially modulated stimuli. We interpret our results in the context of a contemporary two-stage model of binocular contrast gain control, implemented here using a hierarchical Bayesian framework. Posterior distributions of the weight of interocular suppression overlapped with a value of 1 for all dipper data sets, and the model captured well the pattern of thresholds from all three experiments.

In visual perception, an effect known as surround suppression occurs wherein the apparent contrast of a center stimulus is reduced when it is presented within a higher-contrast surrounding stimulus. Many key aspects of visual perception involve surround suppression, yet the neuromodulatory processes involved remain unclear. Psilocybin is a serotonergic psychedelic compound known for its robust effects on visual perception, particularly texture, color, object, and motion perception. We asked whether surround suppression is altered under peak effects of psilocybin. Using a contrast-matching task with different center-surround stimulus configurations, we measured surround suppression after 25 mg of psilocybin compared with placebo (100 mg niacin). Data on harms were collected, and no serious adverse events were reported. After taking psilocybin, participants (n = 6) reported stronger surround suppression of perceived contrast compared to placebo. Furthermore, we found that the intensity of subjective psychedelic visuals induced by psilocybin correlated positively with the magnitude of surround suppression. We note the potential relevance of our findings for the field of psychiatry, given that studies have demonstrated weakened visual surround suppression in both major depressive disorder and schizophrenia. Our findings are thus relevant to understanding the visual effects of psilocybin, and the potential mechanisms of visual disruption in mental health disorders.

The operation of the retina, like other brain circuits, is under modulatory control. One coordinator of changes in retinal function is dopamine, a neuromodulator released in a light-dependent way to adjust vision on a diurnal cycle. Here, we demonstrate that substance P is a similarly powerful retinal modulator that interacts with the dopamine system. By imaging glutamatergic synaptic transmission in larval zebrafish, we find that substance P decreases the contrast sensitivity of ON and OFF visual channels up to 8-fold, with suppression of visual signals being strongest through the "transient" pathway responding to higher frequencies. These actions are exerted in the morning, in large part by suppressing the amplification of visual signals by dopamine, but substance P is almost completely inactive in the afternoon. Modulation of retinal gain is accompanied by changes in patterns of vesicle release at the synapses of bipolar cells: increased gain shifts coding of stimulus strength from the rate of release events to their amplitude generated by a process of multivesicular release (MVR). Together, these actions of substance P reduce the flow of visual information, measured in bits, ∼3-fold. Thus, whereas dopamine "pushes" the retina to transmit information at higher rates in the afternoon, substance P acts in antiphase to suppress dopamine signaling and "pull down" information transmission in the morning., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

Purpose: To describe Light Adjustable Lens (RxSight, Inc) (LAL) visual and refractive outcomes in a Japanese patient population with and without prior refractive surgery., Methods: In this retrospective chart review of patients with cataract in a private eye clinic, 34 eyes from 21 patients underwent cataract surgery with LAL implantation. Eyes underwent light treatment to adjust the patients' refraction after implantation to meet individual visual goals. Standard visual and refractive outcomes were collected. Contrast sensitivity (to assess quality of vision), clinical defocus and vergence curves (to assess range of vision), and patient satisfaction were also collected., Results: The mean prediction error of the light adjustment was -0.04 ± -0.48. Thirty-one eyes (91%) and 33 eyes (97%) were within ±0.25 and ±0.50 diopters (D) of manifest spherical equivalent target, respectively. Thirty-two eyes (94%) had residual refractive cylinder of 0.50 D or less. The full depth of focus was 3.68 D. Monocular contrast sensitivity shows frequencies equivalent to a normal population aged 50 to 60 years. The mean satisfaction score was 8.8 (scale: 1 to 10). There were no adverse events and no eyes lost corrected distance visual acuity from the light treatment., Conclusions: LALs in cataract refractive surgery hold great promise, including for the Japanese population, which have unique ocular biometrics. By providing a safe procedure and the ability for postoperative adjustments, the LAL provided a tailored approach to vision correction, ultimately improving patient outcomes and satisfaction. [ J Refract Surg . 2024;40(11):e854-e862.] ., Competing Interests: Disclosure: The authors have disclosed no potential conflicts of interest, financial or otherwise.

Purpose: To assess the visual quality, patient satisfaction, and photic phenomena 3 and 12 months after the implantation of two similar diffractive intraocular lenses (IOLs) manufactured with different materials., Methods: This retrospective observational study included patients with the AcrySof PanOptix IOL or the Clareon Pan-Optix IOL (both Alcon Laboratories, Inc). Three and 12 months after the surgery, binocular contrast sensitivity under photopic conditions was measured. The presence of dysphotopsias and difficulties when driving in dim light conditions was also reported. Patient satisfaction was assessed through the Catquest 9-SF questionnaire and patients also reported the need for additional spectacles at different distances. Twelve months after the surgery, the presence of posterior capsule opacification and glistening was reported., Results: The study included 59 patients. Contrast sensitivity was stable in both groups 12 months after the surgery, the proportion of patients that always perceived halos decreased approximately 15%, and difficulties when driving at night were minimized. Both groups showed high and similar rates of satisfaction with their vision and achieved spectacle independence rates greater than 85% at the two visits. The presence of posterior capsule opacification was similar for both groups, whereas 64% and 90% of the eyes were free of glistening in the AcrySof and Clareon groups, respectively., Conclusions: Both diffractive IOLs offer consistent visual outcomes and high rates of patient satisfaction during the initial 12 months after surgery. The results also suggest that the novel material may better preserve the transparency of the IOL in the long term. [ J Refract Surg . 2024;40(11):e877-e883.] ., Competing Interests: Disclosure: The authors have disclosed no potential conflicts of interest, financial or otherwise.

Purpose: To evaluate range of visual acuity, visual quality, and safety of the IC-8 small-aperture (SA) intraocular lens (IOL) (Apthera; Bausch & Lomb, Inc) in patients with cataract., Methods: This was a prospective, multicenter, open-label, parallel-group, non-randomized, examiner-masked, 12-month clinical study conducted at 21 sites in the United States. Included patients (N = 453) received either the SA IOL (targeted to -0.75 diopters) in one eye and a monofocal or monofocal toric IOL (targeted to plano) in the fellow eye (SA IOL group, n = 343) or bilateral monofocal/monofocal toric IOLs (control group, n = 110)., Results: At 6 months, the SA IOL group achieved superior binocular uncorrected intermediate and near visual acuity ( P < .0001) and equivalent binocular uncorrected distance visual acuity versus the control group. In SA IOL eyes, 99.1% achieved monocular corrected distance visual acuity of 0.3 logarithm of the minimum angle of resolution or better. The SA IOL and control groups had comparable binocular photopic and mesopic contrast sensitivities at 6 months both with and without glare. The SA IOL group reported few visual symptoms overall, although at higher rates than in the control group., Conclusions: The SA IOL group exhibited improved intermediate and near vision, comparable distance vision and binocular contrast sensitivities, and few visual symptoms or adverse events versus the bilateral monofocal/monofocal toric IOL group, suggesting that the SA IOL is an effective option for presbyopia correction at the time of cataract surgery. [ J Refract Surg . 2024;40(11):e824-e835.] ., Competing Interests: Disclosure: JV is a consultant for AcuFocus, Inc and Bausch & Lomb, Inc; BLF is a consultant for Alcon Laboratories, Inc, Bausch & Lomb, Inc, and Imprimis Pharmaceuticals and has participated in a safety monitoring board or advisory board for Stroma Medical and Ziemer. KS has received grants or contracts from AcuFocus, Inc (payment to institution) and Bausch Health (payment to institution), is a consultant for Bausch & Lomb, Inc, receives honoraria from Bausch & Lomb, Inc, and has received equipment, materials, drugs, medical writing, gifts, or other services from AcuFocus, Inc (delivered to institution) and Bausch & Lomb, Inc (delivered to institution). LL is a current employee of and MM is a former employee of AcuFocus, Inc. SM has disclosed no potential conflicts of interest, financial or otherwise.

Purpose: To assess visual outcomes and stability of lens alignment more than 3 years after implanting either the AT Lisa Tri Toric (Carl Zeiss Meditec) or the Acrysof IQ Restor Toric (Alcon Laboratories, Inc) intraocular lens (IOL)., Methods: Patients who had received either the AT Lisa Tri Toric or the Acrysof IQ Restor Toric IOL were included in the study. The average follow-up period was 5.4 years for the AT Lisa Tri Toric group and 7.9 years for the Acrysof IQ Restor group. The examinations covered included: subjective refraction, monocular and binocular corrected and uncorrected visual acuity at far (4 m), intermediate (75 cm), and near (40 cm) distances, binocular best-corrected defocus curve analysis (4 m), contrast sensitivity evaluation, assessment of IOL axial position, and presence of positive dysphotopsia., Results: A total of 42 eyes were evaluated. Both groups exhibited good long-term lens axial stability. The AT Lisa Tri Toric group had a mean misalignment of 4.8 ± 3.2° from the preoperatively determined axis, whereas the Acrysof IQ Restor Toric group had an average misalignment of 5.4 ± 4.5° (no statistically significant difference, P = .578). Mean achieved spherical equivalent was -0.19 ± 0.36 diopters (D) for the AT Lisa Tri Toric group and 0.15 ± 0.39 D for the Acrysof IQ Restor Toric group. In the AT Lisa Tri Toric group, 18 eyes (72%) achieved an uncorrected distance visual acuity of 0.10 logarithm of the minimum angle of resolution (20/25 Snellen) or better, compared to 15 eyes (88%) in the Acrysof IQ Restor Toric group. Overall, 21 eyes (84%) in the AT Lisa Tri Toric group and 14 eyes (83%) in the Acrysof IQ Restor Toric group achieved a postoperative spherical equivalent refraction between -0.50 and +0.50 D., Conclusions: Both the AT Lisa Tri Toric and the Acrysof IQ Restor Toric IOLs showed good long-term stability and functional outcomes. They proved to be effective options for restoring vision at far, intermediate, and near distances, providing a viable solution for presbyopia correction even several years after implantation. [ J Refract Surg . 2024;40(11):e845-e853.] ., Competing Interests: Disclosure: GUA and RK report research grants, travel expenses, lecture fees, and consulting for Alcon Laboratories, Inc, and research grants, travel expenses, and lecture fees for Carl Zeiss Meditec. The remaining authors have disclosed no potential conflicts of interest, financial or otherwise.

Flash sequences appear as steady emission of light if the frequency is above the flicker-fusion threshold. One can display flicker-fused letters against a background, and using the Talbot-Plateau law, vary the average luminance of the letters to control degree of match to background luminance. We have previously reported that the visual system can identify letters that have an average luminance that equals background luminance, which can be described as an anomalous contrast discrimination. The present work confirms the earlier report, and provides additional evidence that the phenomenon is not based on a shift in luminance balance. We discuss the possible role of ON and OFF retinal channels in registering the anomalous contrast., (© 2024 The Author(s). European Journal of Neuroscience published by Federation of European Neuroscience Societies and John Wiley & Sons Ltd.)

Purpose: This study investigates brimonidine's potential effect on visual functions, particularly contrast sensitivity (CS), an indicator of retinal ganglion cell function., Methods: In this single-blind, randomized clinical trial, 60 patients (aged 23-56) with first-episode acute optic neuritis within seven days of symptom onset were randomly assigned to brimonidine or control groups. The intervention group received brimonidine three times daily for three months, while the control group received synthetic tears with the same dosage and frequency. Primary outcomes were changes in CS, visual acuity (VA), and color vision at one and three months post-treatment. Repeated measures ANOVA was used to assess statistically significant and partial eta squared (η2) values, mean differences, and clinically significance important were reported., Results: All participants completed the study without complications. VA improved significantly in both groups by follow-up end (p < 0.001), with significant improvement from first to third month only in the brimonidine group (p < 0.001). The mean VA difference between groups was not statistically and clinically significant. CS showed statistically significant improvement within both groups (p < 0.001) and between groups (p < 0.001), with a large effect size (partial η2 = 0.28). The mean CS difference between groups (14.5) was clinically considerable. No significant changes in color vision were observed between groups (p = 0.96)., Conclusion: Brimonidine significantly improved contrast sensitivity compared to placebo and was well-tolerated. Its neuroprotective effects suggest it may be beneficial in treating optic neuritis and preserving retinal ganglion cell function., Trial Registration: Prospectively registered at Iranian Clinical Trial Registration; Registration date 3 December 2022; Registration number: IRCT20221127056631N1., Competing Interests: Declaration of competing interest All authors declare that they have no conflict of interest., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Neurons in primary visual cortex (area V1) adapt in varying degrees to the average contrast of the environment, suggesting that the representation of visual stimuli may interact with the state of cortical gain control in complex ways. To investigate this possibility, we measured and analyzed the responses of neural populations in mouse V1 to visual stimuli as a function of contrast in different environments, each characterized by a unique distribution of contrast values. Our findings reveal that, for a fixed stimulus, the population response can be described by a vector function r ( g e c ), where the gain g e is a decreasing function of the mean contrast of the environment. Thus, gain control can be viewed as a reparameterization of a population response curve, which is invariant across environments. Different stimuli are mapped to distinct curves, all originating from a common origin, corresponding to a zero-contrast response. Altogether, our findings provide a straightforward, geometric interpretation of contrast gain control at the population level and show that changes in gain are well matched among members of a population. NEW & NOTEWORTHY The authors study the responses of neural populations in mouse primary visual cortex as a function of stimulus contrast. Measurements are performed in different "environments," each characterized by a different distribution of contrast values. They find that responses across environments can be viewed as a reparameterization of a single contrast-response curve, offering a simple, geometric account of contrast gain control in neural populations.

Previous studies identified two visual stimuli that can shorten the human eye by thickening the choroid after short-term visual stimulation, potentially inhibiting myopia: (1) watching digitally filtered movies where the red plane has full spatial resolution while green and blue are low-pass filtered according to the human longitudinal chromatic aberration (LCA) function (the "red in focus" filter), and (2) reading text with inverted contrast. This study aimed to determine whether combining these two stimuli would have an additive effect on axial length. Twenty-two emmetropic subjects were recruited to read text (standard and inverted contrast) for 30 min from a large screen, 2 m away, either unfiltered or filtered with the "red in focus" filter. Axial length was measured before and after each reading episode using low-coherence interferometry (Lenstar LS 900, Haag Streit). Reading text with conventional contrast polarity (dark letters on a bright background) resulted in no significant axial length change. Adding the "red in focus" filter did not alter the outcome. Consistent with previous findings, reading inverted contrast text made emmetropic eyes shorter. Surprisingly, when the text was combined with the "red in focus" filter, eyes became longer rather than shorter. A possible explanation for this contradictory result is that, for the text stimulus, the "red in focus" filter removes spatial information in the blue channel needed by the retina to use LCA analysis to thicken the choroid., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Purpose: To assess the visual impact of Diffusion Optics Technology™ 0.2 DOT lenses (SightGlass Vision Inc.) designed for myopia control on primary gaze. DOT spectacle lenses contain light scattering elements that scatter light as it passes through the lens which, in turn, reduces retinal image contrast., Methods: Fifty-one children (12.2 ± 1.3, range 10-14 years; 51% females) were randomly assigned to wear DOT spectacle (n = 27) or single vision lenses (n = 24) across six investigational sites in North America. Binocular high- and low-contrast distant visual acuities, near visual acuity, reading speed, contrast sensitivity, stereoacuity and glare were assessed in primary gaze after at least 3 years of wear, with the study 95% powered in all metrics to detect significant differences between the groups., Results: Mean binocular distance high-contrast (-0.09 ± 0.02 vs. -0.08 ± 0.02 logMAR, p = 0.81), low-contrast (0.05 ± 0.02 vs. 0.07 ± 0.02 logMAR, p = 0.52) and near visual acuity with glare sources (-0.06 ± 0.03 vs. -0.09 ± 0.03 logMAR, p = 0.32) were similar for DOT and single vision lens wearers, respectively. Contrast sensitivity was similar between children wearing DOT or single vision lenses across 11 of the 16 spatial frequencies (p > 0.05). Mean stereopsis was similar (p = 0.30) with the DOT lenses (33.2 ± 12.5″) and single vision lenses (38.1 ± 14.2″). Functional reading speed metrics were similar in both study groups, as was the objectively measured head tilt during reading (p > 0.05). The mean halo radius was 0.56° ± 0.17° with the DOT lenses compared with 0.50° ± 0.12° with single vision lenses (p = 0.02), but the statistically significant difference was smaller than the non-inferiority bound of 0.4°., Conclusion: Diffusion optics technology lenses provide a clinically equivalent visual experience to a standard single vision lens., (© 2024 SightGlass Vision. Ophthalmic and Physiological Optics published by John Wiley & Sons Ltd on behalf of College of Optometrists.)

Purpose: To evaluate signs and symptoms in patients diagnosed with dry eye disease (DED), divided into dry eye (DE) groups, in order to find a new biomarker that allows an accurate diagnosis, management and classification of DED., Methods: This cross-sectional, observational study included 71 DED subjects. Subjective symptoms, visual quality and DE signs were assessed using the Ocular Surface Disease Index (OSDI), the Quality of Vision (QoV) questionnaire, best corrected distance visual acuity (VA), functional visual acuity (FVA), contrast sensitivity (CS), high- and low-order corneal aberrations (HOA and LOA, respectively), tear break-up time (TBUT), Meibomian Gland Dysfunction (MGD), Schirmer test, corneal staining, lid wiper epitheliopathy (LWE) and meibography. Participants were classified into three groups based on dryness severity using a cluster analysis, i.e., mild (N = 17, 55.8 ± 15.4 years), moderate (N = 41, 63.5 ± 10.6 years) and severe (N = 13, 65.0 ± 12.0). A new Dry Eye Severity Index (DESI) based on ocular surface signs has been developed and its association with symptoms, visual quality and signs was assessed. Comparisons between groups were made using Kruskal-Wallis and Chi-squared tests. Spearman correlation analysis was also performed., Results: The DESI was based on three tests for DE signs: TBUT, Schirmer test and MGD. The DESI showed significant differences between different pairs of groups: Mild Dryness versus Moderate Dryness (p < 0.001), Mild Dryness versus Severe Dryness (p < 0.001) and Moderate Dryness versus Severe Dryness (p < 0.001). The DESI was significantly correlated with age (rho = -0.30; p = 0.01), OSDI score (rho = -0.32; p = 0.007), QoV score (rho = -0.35; p = 0.003), VA (rho = -0.34; p = 0.003), FVA (rho = -0.38; p = 0.001) and CS (rho = 0.42; p < 0.001) Also, significant differences between the severity groups were found for OSDI and QoV scores, VA, FVA, CS and MGD (p < 0.05)., Conclusions: The DESI has good performance as a biomarker for the diagnosis, classification and management of DED., (© 2024 The Author(s). Ophthalmic and Physiological Optics published by John Wiley & Sons Ltd on behalf of College of Optometrists.)

Objective: The aim of this work is to assess how drivers adapt their driving speed as a self-regulation mechanism when driving under the influence of alcohol, and the influence of alcohol consumption, visual performance, road complexity, and personal traits., Method: Thirty-one volunteers took part in the study. All of them underwent three experimental sessions: baseline (no alcohol), Alcohol 1 (low-moderate dose), and Alcohol 2 (moderate-high dose). Vision was tested using contrast sensitivity and retinal straylight. Driving performance was assessed using a driving simulator. The difference between the driving speed and the speed limit was calculated in 10 road scenarios of different complexity., Results: Drivers adapted their driving speed less (i.e., drove faster) in the Alcohol 1 condition compared with Alcohol 2 ( p = .007). This indicates that participants felt more confident under the influence of a low-moderate dose of alcohol. Participants with better contrast sensitivity drove faster ( p = .021). The complexity of the road and other factors such as driving experience, sex, or driving under the influence of alcohol frequency also influenced speed choice., Conclusions: Drivers under the influence of a low-moderate dose of alcohol seem to be less aware of the risk. Contrast sensitivity is a good predictor of the speed choice when driving under the influence of alcohol. A better understanding of drivers' behavior under the influence of substance use may be useful to adjust and improve traffic laws and driving regulations.

Purpose: To compare intraindividual monocular visual performance of a monofocal extended depth-of-focus (EDOF) and a trifocal EDOF intraocular lens (IOL) following bilateral cataract surgery., Design: Single-center, prospective, fellow-eye comparison clinical trial., Methods: All patients received uneventful bilateral cataract surgery with implantation of the monofocal EDOF Isopure IOL in the dominant eye and the trifocal EDOF FineVision Triumf IOL in the nondominant eye. Intraindividual monocular comparison included visual acuity at various distances, defocus curves, internal total higher-order aberration (HOA), spherical aberration (SA) Z(4.0), IOL decentration, and tilt. Additionally, subjective outcomes were evaluated using Halo and Glare simulation and the Seven-Item Visual-Functioning Index questionnaire., Results: In total, 25 patients (50 eyes) were included. Intraindividual monocular best-corrected distance visual acuity, distance-corrected intermediate visual acuity, and best-corrected near visual acuity were comparable (P > .05). However, monocular contrast acuity (P = .019), distance-corrected near visual acuity (P < .001), and defocus curves at defocus levels of 0.0 D (P = .005) and between -1.5 and -4.0 D (P < .001) differed significantly. At 5 mm, internal HOA and SA Z(4.0) were significantly different (P < .001) and comparable at 3-mm pupil diameter, as were IOL tilt and decentration (P > .05)., Conclusion: In this combined fellow-eye comparison, near vision was significantly better with the trifocal EDOF IOL. The monofocal EDOF IOL demonstrated similar distance and intermediate visual performance as the trifocal EDOF IOL. Overall, low values of photic phenomena and visual impairment were observed., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Purpose: The purpose of this study was to investigate the differences in guttae ultramorphology and their relation to visual function in eyes with Fuchs endothelial corneal dystrophy (FECD)., Methods: Thirty FECD eyes without ocular comorbidities were included. Visual functional parameters (best-corrected visual acuity with high-contrast and low-contrast letters and contrast sensitivity/LogCS) and corneal morphology measured with Scheimpflug tomography (Pentacam) were assessed. The surgically removed Descemet membranes were examined by light and transmission electron microscopy., Results: Preoperative mean best-corrected visual acuity (logarithm of the minimum angle of resolution) was 0.52 ± 0.18, LogCS 0.96 ± 0.21 and central corneal thickness 640 ± 55 μm. All eyes had signs of subclinical corneal edema in Scheimpflug tomography; clinically visible corneal edema was present in 40% of eyes. Histological findings included a posterior fibrillar zone (PFZ) in 10 specimens (33%) and abnormal collagen depositions in Descemet membranes in 14 specimens (47%). Guttae buried within the PFZ were present only in eyes with clinically visible edema (n = 4, 13%). There was no difference in visual function results and tomography parameters between eyes with and without PFZ or between protruding guttae and guttae embedded in a PFZ, respectively., Conclusions: Guttae morphology and density were not correlated with visual functional parameters. Guttae buried in a PFZ occurred only in eyes with clinically manifest edema, and thereby, they are an ultramorphological sign for advanced FECD. Subclinical edema was present in all eyes and might be more relevant for quality of vision than guttae ultramorphology., Competing Interests: The authors have no funding or conflicts of interest to disclose., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Background: To prospectively evaluate binocular visual outcomes after implantation of trifocal intraocular lenses (IOLs) with high-water-content hydrophobic acrylic material in Japanese patients., Methods: In 59 patients (mean age 65.1 ± 7.9 years), Clareon PanOptix (CNWTT0: Alcon) with a high-water-content hydrophobic acrylic material was implanted bilaterally. Three months postoperatively, binocular uncorrected visual acuity (BUCVA) and distance-corrected visual acuity (BDCVA) at distances of 5 m, 80, 60, and 40 cm, binocular defocus curves, and binocular photopic contrast sensitivity were examined. Subjective symptoms (night vision disturbance, glare, halos, haze, or blurry vision) were also assessed., Results: The mean postoperative BUCVA/BDCVA at 5 m, 80 cm, 60 cm, and 40 cm were - 0.115/-0.163, -0.052/-0.047, -0.054/-0.075, and - 0.043/-0.067 logMAR, respectively. A smooth defocus curve, contrast sensitivity within the normal range, and acceptable subjective symptom rates were obtained., Conclusions: The trifocal IOL, composed of a high-water-content hydrophobic acrylic material, provides good continuous binocular vision from distance to near., Trial Registration: This investigator-initiated study was registered in the Japan Registry for Clinical Trials (identifier: jRCTs032220042) on April 26, 2022., (© 2024. The Author(s).)

Purpose: To compare the characteristics of the quantitative contrast sensitivity function (qCSF) in eyes with early keratoconus (Early-KC) and normal control (NC) eyes and investigate the associated factors., Design: A cross-sectional study., Methods: This study included 43 eyes of 43 patients with Early-KC (including subclinical keratoconus [SKC] and forme fruste keratoconus [FFKC]) and 77 NC eyes of 77 participants with corrected distance visual acuity (CDVA) all ≥ 20/20. Contrast sensitivity (CS) was assessed using the qCSF tests. Subgroup analysis was performed according to keratoconus type(SKC and FFKC) and astigmatism(cylindrical refraction >-1.0D or ≤-1.0D)., Results: Sex ratio, spherical refraction, and spherical equivalent (SE) varied significantly between the two groups (all P < 0.01). The area under log CSF (AULCSF), CSF Acuity, and CS at low (1.0 and 1.5 cycles per degree [cpd]) and high (12.0 and 18.0 cpd) spatial frequencies decreased significantly in the Early-KC group than that in the NC group (all P < 0.05). The subgroup analysis revealed a similar decrease in the SKC group (all P < 0.05). AULCSF, CSF Acuity, and CS at high spatial frequencies of patients with cylindrical refraction ≤-1.0D in the Early-KC group decreased significantly (all P < 0.05) than those in the NC group. The index of vertical asymmetry and index of height decentration correlated negatively with CS at 1.5 cpd (r= -0.321 and -0.306; both P < 0.05)., Conclusions: CS decreased significantly at low and high spatial frequencies in Early-KC, though with normal CDVA. The qCSF test can sensitively reflect visual performance in early keratoconus., (© 2024. The Author(s).)

We developed and validated digital twins (DTs) for contrast sensitivity function (CSF) across 12 prediction tasks using a data-driven, generative model approach based on a hierarchical Bayesian model (HBM). For each prediction task, we utilized the HBM to compute the joint distribution of CSF hyperparameters and parameters at the population, subject, and test levels. This computation was based on a combination of historical data (N = 56), any new data from additional subjects (N = 56), and "missing data" from unmeasured conditions. The posterior distributions of the parameters in the unmeasured conditions were used as input for the CSF generative model to generate predicted CSFs. In addition to their accuracy and precision, these predictions were evaluated for their potential as informative priors that enable generation of synthetic quantitative contrast sensitivity function (qCSF) data or rescore existing qCSF data. The DTs demonstrated high accuracy in group level predictions across all tasks and maintained accuracy at the individual subject level when new data were available, with accuracy comparable to and precision lower than the observed data. DT predictions could reduce the data collection burden by more than 50% in qCSF testing when using 25 trials. Although further research is necessary, this study demonstrates the potential of DTs in vision assessment. Predictions from DTs could improve the accuracy, precision, and efficiency of vision assessment and enable personalized medicine, offering more efficient and effective patient care solutions., (© 2024. The Author(s).)

Natural scenes are highly dynamic, challenging the reliability of visual processing. Yet, humans and many animals perform accurate visual behaviors, whereas computer vision devices struggle with rapidly changing background luminance. How does animal vision achieve this? Here, we reveal the algorithms and mechanisms of rapid luminance gain control in Drosophila, resulting in stable visual processing. We identify specific transmedullary neurons as the site of luminance gain control, which pass this property to direction-selective cells. The circuitry further involves wide-field neurons, matching computational predictions that local spatial pooling drive optimal contrast processing in natural scenes when light conditions change rapidly. Experiments and theory argue that a spatially pooled luminance signal achieves luminance gain control via divisive normalization. This process relies on shunting inhibition using the glutamate-gated chloride channel GluClα. Our work describes how the fly robustly processes visual information in dynamically changing natural scenes, a common challenge of all visual systems., (© 2024. The Author(s).)

In binocular vision, the relative strength of the input from the two eyes can have significant functional impact. These inputs are typically balanced; however, in some conditions (e.g., amblyopia), one eye will dominate over the other. To quantify imbalances in binocular vision, we have developed the Dichoptic Contrast Ordering Test (DiCOT). Implemented on a tablet device, the program uses rankings of perceived contrast (of dichoptically presented stimuli) to find a scaling factor that balances the two eyes. We measured how physical interventions (applied to one eye) affect the DiCOT measurements, including neutral density (ND) filters, Bangerter filters, and optical blur introduced by a +3-diopter (D) lens. The DiCOT results were compared to those from the Dichoptic Letter Test (DLT). Both the DiCOT and the DLT showed excellent test-retest reliability; however, the magnitude of the imbalances introduced by the interventions was greater in the DLT. To find consistency between the methods, rescaling the DiCOT results from individual conditions gave good results. However, the adjustments required for the +3-D lens condition were quite different from those for the ND and Bangerter filters. Our results indicate that the DiCOT and DLT measures partially separate aspects of binocular imbalance. This supports the simultaneous use of both measures in future studies.

Diffusion optics Technology (DOT) myopia control spectacle lenses are based on contrast theory. This innovative theory represents a radical departure from the classical concept of visual deprivation myopia. However, traditional theories have evolved, arriving at remarkably similar solutions for myopia control as the DOT lenses. Nonetheless, contrast theory still represents a departure from mainstream theories. Here, in an effort to resolve discrepancies, we review the science behind contrast theory and compare it to more conventional blur and defocus theories. Finally, we consider the implications of the different theories for the rational design of myopia control solutions.

Purpose: Studies have reported that individuals with certain ocular disorders may have significant decreases in contrast sensitivity function (CSF) despite having normal or near normal visual acuity (VA). This study seeks to elucidate this phenomenon by investigating the relationship between VA and CSF., Methods: We analyzed data from 14 eyes tested with Electronic Early Treatment Diabetic Retinopathy and quantitative CSF under four Bangerter foil conditions (n = 56). From the CSF data, we estimated peak gain, peak frequency, and contrast sensitivity acuity (CSA). We explored the correlations between VA and various CSF parameters and evaluated five predictive models of VA using CSA alone and in combination with additional CSF parameters through ridge regression., Results: We found that similar VA scores can correspond with markedly different CSFs and observed significant correlations among all CSF parameters and between VA and each CSF parameter (all P < 0.001). The most effective predictive model, incorporating CSA and peak gain, explained 90.97% of the variance with a root mean squared error of 0.0676 logMAR, which is comparable with the average standard deviation of the VA scores (0.0627 logMAR) and accounted for 38.6% of the residual variance not explained by the CSA-alone model., Conclusions: This study offers the first empirical inference of the quantitative relationship between VA and CSF, suggesting that various CSF parameter combinations can yield identical VA. This might help to explain why some clinical populations with normal or near-normal VA exhibit significant CSF deficits and calls for further research in different clinical settings.

Purpose: The mechanisms underlying a myopia control strategy using scattering lenses are unclear. Therefore, this study investigates the short-term effects of scatter lenses on central and peripheral choroidal thickness and axial length, which serve as a biomarker in myopia progression research., Methods: In total, 23 participants underwent a 60-minute lens wear phase each to five lens conditions: medium peripheral scattering, high peripheral scattering, medium full-field scattering, high full-field scattering and control (clear lens). Central and peripheral choroidal thickness, foveal axial length, and central visual acuity were measured before and after each lens wear condition., Results: Peripheral choroidal thickening was found after the lens wear phase of the medium peripheral scattering condition (+3.91 ± 5.37 µm, P = 0.04), revealing a significant difference to the control lens condition (P = 0.004), most pronounced in the superior peripheral retina (+1.95 ± 10.74 µm, P = 0.02). In the central retina, significant choroidal thickening was only found in the nasal part after exposure to medium full-field scattering (+3.91 ± 11.72 µm) compared to the control condition (P = 0.001). High peripheral and full-field scattering conditions did not significantly affect central or peripheral choroidal thickness. Visual acuity was significantly reduced in the full-field scattering conditions compared to control and peripheral scattering lenses, with no improvement after 60-minute lens wear. Axial length did not differ significantly after 60-minute exposure to any scattering lens condition or when compared to the control lens., Conclusions: The results indicate a local retinal contrast detection mechanism signals the choroid to thicken peripherally after adaptation to medium peripheral scattering but not high peripheral scattering or full-field scattering at all, while central thickening was only significant nasally after exposure to medium full-field scattering. This emphasizes the importance of the peripheral retina and the level of contrast reduction in the context of myopia research., Translational Relevance: This finding gives insight into the mechanism behind the myopia control strategy inducing peripheral scattering.

Purpose: Palinopsia (persistent afterimages and/or trailing) is a common but poorly understood symptom of the neurological condition visual snow syndrome. This study aimed to collect a phenotypical description of palinopsia in visual snow syndrome and probe for abnormalities in temporal visual processing, hypothesizing that palinopsia could arise from increased visibility of normal afterimage signals or prolonged visible persistence., Methods: Thirty controls and 31 participants with visual snow syndrome (18 with migraine) took part. Participants completed a palinopsia symptom questionnaire. Contrast detection thresholds were measured before and after brief exposure to a spatial grating because deficient contrast adaptation could increase afterimage visibility. Temporal integration and segregation were assessed using missing-element and odd-element tasks, respectively, because prolonged persistence would promote integration at wide temporal offsets. To distinguish the effects of visual snow syndrome from comorbid migraine, 25 people with migraine alone participated in an additional experiment., Results: Palinopsia was common in visual snow syndrome, typically presenting as unformed images that were frequently noticed. Contrary to our hypotheses, we found neither reduced contrast adaptation (F(3.22, 190.21) = 0.71, P = 0.56) nor significantly prolonged temporal integration thresholds (F(1, 59) = 2.35, P = 0.13) in visual snow syndrome. Instead, participants with visual snow syndrome could segregate stimuli in closer succession than controls (F(1, 59) = 4.62, P = 0.04, ηp2 = 0.073) regardless of co-occurring migraine (F(2, 53) = 1.22, P = 0.30). In contrast, individuals with migraine alone exhibited impaired integration (F(2, 53) = 4.44, P = 0.017, ηp2 = 0.14)., Conclusions: Although neither deficient contrast adaptation nor prolonged visible persistence explains palinopsia, temporal resolution of spatial cues is enhanced and potentially more flexible in visual snow syndrome.

Purpose: To assess the visual outcomes in patients with cataract implanted with a small-aperture intraocular lens (IOL) in eyes with aberrated corneas., Methods: This prospective, non-interventional, single-center clinical study was conducted at Singapore National Eye Centre, Singapore. Twenty-one patients with aberrated corneas had IC-8 IOL (Bausch & Lomb, Inc) implantation. An aberrated cornea was defined as from natural causes: keratoconus (n = 1, 4.8%), high coma (n = 2, 9.5%), corneal scar (n = 1, 4.8%), or iatrogenic causes: keratorefractive procedure (n = 17, 86%). Uncorrected and corrected visual acuities were measured at distance (600 cm) (UDVA and CDVA), intermediate (66.7 cm) (UIVA and CIVA), and near (40 cm) (UNVA and CIVA). Defocus curve was tested monocularly and binocularly. Contrast sensitivity (CS) was measured under photopic and mesopic conditions with and without glare., Results: In IC-8 eyes, the mean ± standard deviation UDVA, UIVA, and UNVA was 0.24 ± 0.18, 0.19 ± 0.18, and 0.14 ± 0.14 logMAR, respectively. Mean CDVA, CIVA, and CNVA in IC-8 eyes was 0.12 ± 0.17, 0.16 ± 0.15, and 0.19 ± 0.13 logMAR, respectively. Binocular mean UDVA, UIVA, and UNVA was 0.07 ± 0.10, 0.07 ± 0.10, and 0.13 ± 0.12 logMAR, respectively. Defocus curve testing yielded a depth of focus of 1.50 D monocularly and 2.00 D binocularly at a 0.2 logMAR threshold. Photopic binocular CS with and without glare improved over monocular CS of IC-8 and fellow eyes under all spatial frequencies. Mesopic binocular CS with and without glare were similar among monocular IC-8 and fellow eyes across spatial frequencies. Most patients reported low levels of visual symptoms., Conclusions: The IC-8 IOL provides good monocular and binocular visual outcomes for patients with cataract who had aberrated corneas. [ J Refract Surg . 2024;40(10):e716-e723.] .

The present study continued to investigate whether the effects of length misperception caused by cross-shaped (formed by two pairs of the oppositely oriented Müller-Lyer wings) contextual distractors can be explained by the combined manifestation of two different (i.e., the Müller-Lyer and filled-space) geometric illusions of extent. In psychophysical experiments, the luminance of one pair of wings was randomly changed, while the luminance of the other pair remained constant. Two different distractor orientations were used-when the wings with constant luminance formed the right side of the cross or the left side, otherwise. To separately evaluate the manifestation of the Müller-Lyer illusion under different luminance conditions, two distracting crosses of the same orientation were attached to the lateral stimulus terminators in the first series of experiments. In the following four series, a single distracting cross (with different orientation) was attached to one of the lateral stimulus terminators and various combinations of the constant and background luminance were used. To interpret the experimental data, we used the basic computational principles of previously developed quantitative models of hypothetical visual mechanisms underlying the emergence of the Müller-Lyer illusion and the filled-space illusion. It was shown that the results of theoretical calculations adequately approximate the experimental curves obtained for all modifications of stimuli, which strongly supports the suggestion that the joint manifestations of these two illusions can be considered among the main factors determining the features of the illusion investigated., (© 2024. The Psychonomic Society, Inc.)

Background: We developed and tested a dichoptic treatment designed for younger children that can be viewed freely and involves a dichoptic manipulation of a popular animation series that enables contrast-rebalancing without disrupting fusion. Our aim was to assess whether this novel amblyopia treatment is superior to patching in children aged 3-5 years., Methods: A total of 34 children with amblyopia were randomly assigned to contrast-rebalanced dichoptic cartoons (4 hours/week) or patching (14 hours/week) for 2 weeks. Children in the cartoon group continued watching cartoons for an additional 2 weeks. Designed to target the youngest and most treatable children, the dichoptic cartoons presented the entire scene to the amblyopic eye at 100% contrast, while the fellow eye view was presented at reduced contrast with the main character omitted. Best-corrected visual acuity (BCVA), stereoacuity, suppression, and manual dexterity were measured at each visit., Results: After 2 weeks, improvement in amblyopic eye BCVA was greater for dichoptic treatment than for patching, with a mean improvement of 0.11 ± 0.08 versus 0.06 ± 0.09 logMAR, respectively (P = 0.04). Stereoacuity, suppression, and manual dexterity did not improve significantly more in the dichoptic group than the patching group at 2 weeks. After 4 weeks of dichoptic cartoon treatment, mean visual acuity improvement in the dichoptic group was 0.16 logMAR (95% CI, 0.10-0.21)., Conclusions: In our study cohort, a contrast-rebalanced dichoptic cartoon was more effective than patching in treating childhood amblyopia after 2 weeks. Dichoptic cartoons that rebalance contrast to overcome suppression provide an additional treatment option for amblyopia in young children., (Copyright © 2024 American Association for Pediatric Ophthalmology and Strabismus. Published by Elsevier Inc. All rights reserved.)

Illusory contours demonstrate an important function of the visual system-object inference from incomplete boundaries, which can arise from factors such as low luminance, camouflage, or occlusion. Illusory contours can be perceived with varying degrees of clarity depending on the features of their inducers. The present study aimed to evaluate whether illusory contour clarity influences visual search efficiency. Experiment 1 compared visual search performance for Kanizsa illusory stimuli and nonillusory inducer stimuli when manipulating inducer size as a clarity factor. Experiment 2 examined the effects of illusory contour clarity on visual search by manipulating the number of rings with missing arcs (i.e., line ends) comprising the inducers, for both illusory and nonillusory stimuli. To investigate whether surface alterations had an impact on visual search in Experiment 1, Experiment 3 examined search performance for Kanizsa-like stimuli formed from "smoothed" inducers compared with standard Kanizsa figures. The results of Experiments 1 and 2 indicated that while Kanizsa produced inefficient search, this was not contingent on the clarity of the illusory contours. Experiment 3 suggested that surface alterations of Kanizsa figures did impact visual search performance. Together, the results indicated that illusory contour clarity did not have much bearing on search performance. In certain conditions, Kanizsa figures even facilitated search compared with nonillusory stimuli, suggesting that rather than contour inference, surface features might have greater relevance in guiding visual attention., (© 2024. The Psychonomic Society, Inc.)

Importance: Vision impairment is a potentially modifiable risk factor for dementia. Although few prior studies have estimated the contribution of vision impairments to dementia, none have reported on multiple objectively measured vision impairments (eg, distance and near visual acuity and contrast sensitivity) in a nationally representative sample of older adults., Objective: To quantify population attributable fractions of dementia from objective vision impairments in older adults, stratified by age, self-reported sex, self-reported race and ethnicity, and educational attainment., Design, Setting, and Participants: This was a population-based cross-sectional analysis in the National Health and Aging Trends Study, which gathers nationally representative information on Medicare beneficiaries aged 65 years and older in the US. A total of 2767 community-dwelling adults eligible for vision and cognitive testing in 2021 were included. Data were analyzed from April to August 2023., Exposures: Near and distance visual acuity impairments were each defined as >0.30 logMAR. Contrast sensitivity impairment was defined as <1.55 logCS. At least 1 vision impairment was defined as impairment to either near acuity, distance acuity, or contrast sensitivity., Main Outcomes and Measures: Adjusted population attributable fractions of prevalent dementia, defined using a standardized algorithmic diagnosis (≥1.5 SDs below mean on 1 or more cognitive domains, self- or proxy-reported dementia diagnosis, or the Ascertain Dementia-8 Dementia Screening Interview Score of probable dementia)., Results: The survey-weighted prevalence of vision impairment among participants aged 71 and older (1575 [54.7%] female and 1192 [45.3%] male; 570 [8.0%] non-Hispanic Black, 132 [81.7%] Hispanic, 2004 [81.7%] non-Hispanic White, and 61 [3.3%] non-Hispanic other) was 32.2% (95% CI, 29.7-34.6). The population attributable fraction of prevalent dementia from at least 1 vision impairment was 19.0% (95% CI, 8.2-29.7). Contrast sensitivity impairment yielded the strongest attributable fraction among all impairments (15.0%; 95% CI, 6.6-23.6), followed by near acuity (9.7%; 95% CI, 2.6-17.0) and distance acuity (4.9%; 95% CI, 0.1-9.9). Population attributable fractions from at least 1 impairment were highest among participants aged 71 to 79 years (24.3%; 95% CI, 6.6-41.8), female (26.8%; 95% CI, 12.2-39.9), and non-Hispanic White (22.3%; 95% CI, 9.6-34.5) subpopulations, with estimates consistent across educational strata., Conclusions and Relevance: The population attributable fraction of dementia from vision impairments ranged from 4.9%-19.0%. While not proving a cause-and-effect relationship, these findings support inclusion of multiple objective measures of vision impairments, including contrast sensitivity and visual acuity, to capture the total potential impact of addressing vision impairment on dementia.

Neon color spreading (NCS) is an illusory color phenomenon that provides a dramatic example of surface completion and filling-in. Numerous studies have varied both spatial and temporal aspects of the neon-generating stimulus to explore variations in the strength of the effect. Here, we take a novel, parametric, low-level psychophysical approach to studying NCS in two experiments. In Experiment 1, we test the ability of both cone-isolating and equiluminant stimuli to generate neon color spreading for both increments and decrements in cone modulations. As expected, sensitivity was low to S(hort-wavelength) cone stimuli due to their poor spatial resolution, but sensitivity was similar for the other color directions. We show that when these differences in detection sensitivity are accounted for, the particular cone type, and the polarity (increment or decrement), make little difference in generating neon color spreading, with NCS visible at about twice detection threshold level in all cases. In Experiment 2, we use L-cone flicker modulations (reddish and greenish excursions around grey) to study sensitivity to NCS as a function of temporal frequency from 0.5 to 8 Hz. After accounting for detectability, the temporal contrast sensitivity functions for NCS are approximately constant or even increase over the studied frequency range. Therefore there is no evidence in this study that the processes underlying NCS are slower than the low-level processes of simple flicker detection. These results point to relatively fast mechanisms, not slow diffusion processes, as the substrate for NCS., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Purpose: Assessment of central and peripheral contrast sensitivity (CS) in thyroid eye disease (TED) with and without dysthyroid optic neuropathy (DON)., Methods: This cross-sectional study enrolled 33 eyes of 18 treatment-naïve TED patients and 18 age- and sex-matched healthy controls for comparative analysis. A detailed ophthalmic examination included visual acuity (VA), intraocular pressure measurement, slit-lamp biomicroscopy, and CS testing (central and four peripheral regions) using Spaeth-Richman Contrast Sensitivity test was done., Results: The average age of TED patients was 47.17 ± 13.99 years and a female preponderance was noted (66.66%, n = 12). Twenty-five eyes (75.8%) were diagnosed as TED without DON, while eight eyes (24.2%) had DON. Nine eyes (27.2%) were in the active stage of disease and 29 eyes (87.8%) had proptosis. The difference in mean logMAR visual acuities between TED patients and controls was statistically insignificant ( P = 0.189), but a significant difference was noted in central and total CS score ( P < 0.001, Wilcoxon-Mann-Whitney test). On CS comparison between DON and non-DON eyes, a significant difference in average scores was noted in central and all peripheral areas ( P < 0.05, Wilcoxon-Mann-Whitney test). With increasing clinical activity score, a statistically significant reduction was noted in CS in three out of four peripheral regions (Spearman correlation, P < 0.05)., Conclusion: Visual function compromise can be detected in TED in the presence of intact VA, by testing CS. Peripheral CS deteriorates with increasing inflammation and in DON. Serial monitoring of both central and peripheral CS may help in diagnosing DON early., (Copyright © 2024 Copyright: © 2024 Indian Journal of Ophthalmology.)

Purpose: Our aim was to explore the effect of ambient lighting on the pattern ERG (PERG)., Methods: We compared PERGs recorded in two conditions; room lights on and room lights off. PERGs from 21 adult participants were recorded from each eye to high contrast checks of 50' side width, reversing 3rps in a large (30°) and then standard (15°) field. This was performed first in lights-ON conditions, then 2 min after the room lights were switched off. A minimum of 2 averages of 300 trials were acquired for each condition. A subset of 10 participants had PERGs recorded to a 50' check width with a range of stimulus contrasts (96-18%), also to a range of different check widths (100'-12') at high contrast in both ambient lighting conditions in a 30° field., Results: The lights-ON P50 median peak time (PT) was 3 ms earlier than the lights-OFF P50 from the 30° field (range 0-5 ms) and 15° field (range 0-6 ms). The earlier lights-ON P50 PT was evident at different stimulus contrasts, even after accounting for stimulus contrast reductions associated with stray ambient lighting in lights-ON conditions. Lights-OFF and lights-ON P50 PT were similar to different check widths; the lights-OFF P50 PT to a 50' check width matched the lights-ON P50 PT to a 25' check width., Conclusion: PERG P50 PT in lights-ON ambient light conditions can be earlier than in lights-OFF ambient light conditions. The difference in P50 PT with ambient light may reflect alterations in spatial sensitivity associated with retinal adaptation. These results emphasise the clinical importance of consistent ambient lighting for PERG recording and calibration., (© 2024. The Author(s).)

Purpose: To evaluate the impact of baseline and change in vision on the risk of developing dementia., Design: Retrospective cohort study., Methods: This longitudinal analysis utilized data from the 2021 and 2022 National Health and Aging Trends Study. Binocular presenting vision was assessed, including distance (DVA) and near (NVA) visual acuity, and contrast sensitivity (CS). Dementia status was defined based on: (1) medical diagnosis of dementia, (2) dementia score, or (3) poor cognitive test performance., Results: Of the 2,159 adults included in this study, weighted mean (SD) age was 77.9 years (5.2), with the majority being female (weighted: 54%), and White (88%). The baseline median (interquartile range [IQR]) DVA was 0.08 (0-0.20) logMAR, NVA was 0.17 (0.09-0.26) logMAR, and CS was 1.80 (1.65-1.85) logCS. Over the 1-year follow up period, 192 (6.6%) adults developed dementia. In time-to-event analyses, baseline DVA (HR: 1.08 [95% CI: 1.02-1.14], per 0.1 logMAR), NVA (HR: 1.07 [95% CI: 1.01-1.13], per 0.1 logMAR), and CS (HR: 1.09 [95% CI: 1.03-1.15], per 0.1 logCS) were associated with greater likelihood of incident dementia. Further, change in CS (HR: 1.14 [95% CI: 1.04-1.25], per 0.1 logCS worse/year), but not VA, was associated with greater likelihood of incident dementia., Conclusions: Worse baseline VA and CS are associated with greater likelihood of incident dementia. Further, worsening CS over time, but not VA, was associated with higher likelihood of incident dementia. Future work is needed to study interventions targeted at improving vision deficits and examine their impact on decreasing dementia risk., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background: To evaluate clinical outcomes and visual quality 3 months after mini-monovision (spherical equivalent [SE] between - 0.25 D and - 0.50 D) femtosecond laser-assisted in situ keratomileusis (FS-LASIK) for correction of high myopia in patients with presbyopia., Methods: Patients who had mini-monovision FS-LASIK for high myopia (SE < -6.0 D) and aged between 40 and 50 years were included. At the 3-month postoperative visit, we evaluated full range of visual acuity; defocus curve; optical quality; accommodation function, contrast sensitivity and stereopsis. Binocular tests were done twice, once in mini-monovision condition and once with the residual myopia in the non-dominant eye corrected. Subjective visual quality was evaluated with questionnaire postoperatively with mini-monovision correction., Results: Clinical data of 31 cases were analyzed. The average patient age was 42.58 ± 3.06 years. At the 3-month follow-up, the mean uncorrected binocular visual acuity at distance, intermediate, and near was - 0.11 ± 0.07, -0.06 ± 0.10, and 0.04 ± 0.11 logMAR separately. In comparison, patients with binocular full distance correction achieved better uncorrected distance visual acuity (UDVA), and they achieved superior uncorrected near visual acuity (UNVA, P = 0.04) with mini-monovision correction. FS-LASIK induced significant increases in higher-order aberrations (HOAs) (P < 0.001). For accommodative function, only the negative relative accommodation (NRA) improved significantly after surgery (P < 0.001). A slight decrease in contrast sensitivity was observed at low spatial frequency with mini-monovision correction (P < 0.05). Questionnaire demonstrated high satisfaction with near vision and visual quality., Conclusion: FS-LASIK with mini-monovision (SE between - 0.25 D and - 0.50 D) appeared to be safe and effective in treating high myopia combined with presbyopia to get satisfying visual quality at distant and at near., (© 2024. The Author(s).)

Background: Instrumental activities of daily living (IADL) are typically self-reported ability to perform complex tasks vital for independent living. There is a need for a complementary objective, performance-based approach especially in tracking outcomes in visual rehabilitation for patients with irreversible vision impairment ("low vision"). Our goals are: (1) To describe the validity of timed performance of instrumental activities of daily living (timed IADL or TIADL) tasks in individuals with irreversible vision impairment, by examining its association with visual function (visual acuity, contrast sensitivity, visual field), (2) To explore the correlation between TIADL and self-reported IADL., Methods: Twenty TIADL tasks were administered to 88 patients (median age 63.3 years, IQR 37.4-78.0) recruited from the UAB Department of Ophthalmology, Callahan Eye Hospital Clinics. An average Z-score incorporating time and accuracy of task completion was constructed. Minor accuracy errors were penalized 1 standard deviation from their calculated Z-score and major accuracy errors were assigned maximum allotted time. Linear regression was used to analyze the association between TIADL score and measured visual acuity (Early Treatment Diabetic Retinopathy Study, ETDRS chart), contrast sensitivity (Pelli-Robson), and binocular visual field (Esterman) with an unadjusted model and an adjusted model accounting for age, comorbidities, and depression scale (Center for Epidemiological Studies Depression, CES-D). Pearson correlation was used to estimate the correlation between TIADL and IADL., Results: Increased time to task completion was associated with decreased visual function. Each decreased line of ETDRS read was associated with an increase of 0.002 (95% CI 0.001, 0.002) Z-score (P < 0.01). A decreased ability to discern each Pelli-Robson letter was associated with an increase of 0.26 (95% CI 0.19, 0.33) Z-score (P < 0.01). For each less Esterman target identified, there was an increase of 0.01 (95% CI 0.003, 0.02) Z-score. Self-reported IADL and TIADL were correlated for reading tasks such as newspapers, nutrients on food can, and microwave timer (P < 0.05)., Conclusions: Longer time to perform TIADL is associated with decreased visual acuity, contrast sensitivity, and binocular visual field. TIADL and self-reported IADL are significantly correlated for reading tasks providing an accurate, complementary outcome measure in clinical practice and research., (© 2024. The Author(s).)

Objective: To investigate the effect of wearing dual-focus soft contact lenses (DFSCL) on the visual performance of school-age children., Methods: In this randomized controlled clinical trial, 64 children aged 8 to 12 years with spherical equivalent refraction between -0.75 D and -4.00 D were recruited in our hospital in October 2022. Using the envelope method, the subjects were evenly and randomly assigned to the control group wearing single vision spectacles (SVS) or the intervention group wearing MiSight dual-focus soft contact lenses (DFSCL) from CooperVision. Follow-up examinations were conducted once every 3 months. The corrected visual acuity, contrast sensitivity function (CSF), and the scores for National Eye Institute Refractive Error Quality of Life Instrument-42 (NEI-RQL-42) were compared between the control and intervention groups., Results: By December 2023, a total of 58 subjects completed follow-up (30 in the SVS group and 28 in the DFSCL group). No significant difference in corrected visual acuity was observed between subjects wearing DFSCL and those wearing SVS. The CSF of the DFSCL group was comparable to that of the SVS group across the spatial frequencies of 3, 6, 12, and 18 cpd ( P >0.05). According to the results of the NEI-RQL-42 survey at the 6-month follow-up, the score for ocular discomfort symptoms was 89±14 in the SVS group and 79±16 in the DFSCL group ( P =0.008), reflecting that the DFSCL group had a 12.66% higher level of discomfort. For appearance, the score was 70±32 in the SVS group and 92±22 in the DFSCL group ( P =0.002), showing a 31.43% improvement in the DFSCL group., Conclusion: In addition to providing the normal visual acuity and CSF, wearing MiSight DFSCL also leads to better satisfaction with the appearance., Competing Interests: 利益冲突　本文作者刘陇黔是本刊编委会编委。该文在编辑评审过程中所有流程严格按照期刊政策进行，且未经其本人经手处理。除此之外，所有作者声明不存在利益冲突。, (© 2024《四川大学学报（医学版）》编辑部 版权所有Copyright ©2024 Editorial Office of Journal of Sichuan University (Medical Sciences).)

Lighting modification is commonly performed by optometrists and occupational therapists to enhance visibility and visual comfort among schoolchildren with low vision. The purpose of this study is to determine the optimal illumination level for visual function and visual comfort of schoolchildren with low vision and the relationship between them. A cross-sectional study was conducted to assess five levels of illumination ranging from 125 lux to 2000 lux to determine the optimal illumination for visual functions and visual comfort in schoolchildren with low vision from a special education school for blind in Malaysia. Purposive sampling was done to recruit forty-two schoolchildren with low vision for this study. Visual functions assessed were visual acuity, measured using the Early Treatment Diabetic Retinopathy Study LogMAR chart at distance and near, contrast sensitivity (CS) measured using the Pelli-Robson chart at distance and the Mars CS chart at near. Reading speed was determined using the Universiti Kebangsaan Malaysia Malay Language Related Word Reading Text test chart. Subjects were asked to rate their visual comfort using a validated questionnaire at the end of each measurement of visual functions and reading speed for the different illumination levels. Visual acuity and contrast sensitivity at distance and near, visual comfort and reading speed improved significantly with increase in illumination levels (p<0.05). However, the interaction between illumination level and level of low vision was not significant (p>0.05). Visual comfort was significantly associated with visual function (p<0.05), while direct association between visual comfort and illumination level was not significant (p>0.05). Optimal illumination for improvement of visual function, reading speed and visual comfort range from 276.67 lux to 701.59 lux. Majority of the schoolchildren with low vision had improved visual function, reading speed and visual comfort with increased illumination. Illumination of at least 600 lux is recommended for maximum visual functioning and visual comfort of schoolchildren with low vision., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Yong et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Background: To compare clinical outcomes of trifocal intraocular lens in patients with and without prior history of laser in situ keratomileusis (LASIK)., Methods: A retrospective study included patients who underwent bilateral cataract surgery and PanOptix trifocal intraocular lens (IOLs) implantation. Patients were grouped: Group A for patients with history of LASIK and Group B for patients without history of LASIK. Postoperative outcome measures comprised distance, intermediate, and near visual acuity, manifest refraction, defocus curve, contrast sensitivity, visual quality, patient satisfaction, and the rate of spectacle independence., Results: A total of 288 eyes (144 patients) were included: 132 eyes in Group A and 156 eyes in Group B. At 6 months post-surgery, patients of both groups achieved a continuous satisfying visual acuity from 33 cm to distance. 73% of eyes in Group A and 75% of eyes in Group B were within ± 0.50 D of emmetropia (P > 0.05). The percentages of eyes within ± 1.00 D of emmetropia were 98% for Group A and 96% for Group B (P > 0.05). The total scores of satisfaction were 52.58 ± 3.46 for Group A and 53.23 ± 3.46 for Group B (P > 0.05). Most of patients (98% for Group A, 99% for Group B) were able to be spectacle independence for daily living. 53% of patients in Group A and 51% in Group B experiencd mild to moderate negative visual symptoms, which made it a little or moderate difficult to drive at night., Conclusions: Cataract patients with and without history of LASIK could safely undergo implantation of the PanOptix IOLs, which results in precise refractive outcomes and satisfactory visual acuity. Although contrast sensitivity decreased and some negative visual symptoms were observed, patients' satisfaction was generally high due to the high rate of spectacles independence. There were no statistically significant differences between the study groups., (© 2024. The Author(s).)

Contrast sensitivity (CS), which constrains human vision, decreases from fovea to periphery, from the horizontal to the vertical meridian, and from the lower vertical to the upper vertical meridian. It also depends on spatial frequency (SF), and the contrast sensitivity function (CSF) depicts this relation. To compensate for these visual constraints, we constantly make saccades and foveate on relevant objects in the scene. Already before saccade onset, presaccadic attention shifts to the saccade target and enhances perception. However, it is unknown whether and how it modulates the interplay between CS and SF, and if this effect varies around polar angle meridians. CS enhancement may result from a horizontal or vertical shift of the CSF, increase in bandwidth, or any combination. In addition, presaccadic attention could enhance CS similarly around the visual field, or it could benefit perception more at locations with poorer performance (i.e., vertical meridian). Here, we investigated these possibilities by extracting key attributes of the CSF of human observers. The results reveal that presaccadic attention (1) increases CS across SF, (2) increases the most preferred and the highest discernable SF, and (3) narrows the bandwidth. Therefore, presaccadic attention helps bridge the gap between presaccadic and postsaccadic input by increasing visibility at the saccade target. Counterintuitively, this CS enhancement was more pronounced where perception is better-along the horizontal than the vertical meridian-exacerbating polar angle asymmetries. Our results call for an investigation of the differential neural modulations underlying presaccadic perceptual changes for different saccade directions., Competing Interests: The authors declare no competing financial interests., (Copyright © 2024 Kwak et al.)

The presaccadic preview of a peripheral target enhances the efficiency of its postsaccadic processing, termed the extrafoveal preview effect. Peripheral visual performance-and thus the quality of the preview-varies around the visual field, even at isoeccentric locations: It is better along the horizontal than vertical meridian and along the lower than upper vertical meridian. To investigate whether these polar angle asymmetries influence the preview effect, we asked human participants to preview four tilted gratings at the cardinals, until a central cue indicated which one to saccade to. During the saccade, the target orientation either remained or slightly changed (valid/invalid preview). After saccade landing, participants discriminated the orientation of the (briefly presented) second grating. Stimulus contrast was titrated with adaptive staircases to assess visual performance. Expectedly, valid previews increased participants' postsaccadic contrast sensitivity. This preview benefit, however, was inversely related to polar angle perceptual asymmetries; largest at the upper, and smallest at the horizontal meridian. This finding reveals that the visual system compensates for peripheral asymmetries when integrating information across saccades, by selectively assigning higher weights to the less-well perceived preview information. Our study supports the recent line of evidence showing that perceptual dynamics around saccades vary with eye movement direction., Competing Interests: Competing interests statement:The authors declare no competing interest.

Purpose: To assess structural (optical coherence tomography, fundus autofluorescence) and functional (contrast sensitivity and visual field) test results which were used for detecting early retinal changes in patients using oral hydroxychloroquine., Methods: Patients using oral hydroxychloroquine for at least one year were divided into two groups according to the duration of drug use. Groups 1 and 2 consisted of patients with drug use for more than 5 years and 1-5 years, respectively. The drug-using groups were compared with the control group. The mean retinal nerve fiber layer (RNFL), central macular thickness (CMT), ganglion cell-inner plexiform layer (GC-IPL), static 10-2 visual field, fundus autofluorescence (FAF) imaging, and contrast sensitivity tests were performed and statistically compared between groups., Results: Median and temporal quadrant RNFL thicknesses were found to be statistically significantly lower in the drug groups. In the drug groups, the GC-IPL sectoral and mean thicknesses were found to be statistically lower in all quadrants. Central macular thickness was also found to be similar in all three groups. There was no significant difference between the groups in visual field parameters. Macular FAF images were significantly higher in the drug users, but there was no significant difference between the three groups in foveal FAF images. Contrast sensitivity measurements were significantly lower in the drug groups than in the control group at all spatial frequencies except 6 and 18 cycles/degree., Conclusions: The combined use of structural and functional tests in patients using hydroxychloroquine provides useful information in detecting early retinal changes., (© 2024. The Author(s), under exclusive licence to Springer Nature B.V.)

The extended depth-of-focus AcrySof IQ Vivity intraocular lens technology offers promising features for presbyopia management, evaluated in this research in a 6 months real-world setting. Prospective interventional mono-centric study including 40 patients who underwent elective bilateral phacoemulsification. We performed one pre-operative visit (V0) and one evaluation six months post-operatively (V1), evaluating uncorrected and corrected visual acuity for near (UNVA/CNVA), intermediate (UIVA/CIVA) and far (UDVA/UCVA), slit-lamp evaluation, tomography with static pupillometry, endothelial cell count and contrast sensitivity chart. In order to assess post-operative Quality of Life, we administered the patients McAlinden's Quality of Vision test and Morlock's Patient-Reported Spectacle Independence Questionnaire. We divided eyes in with Toric-IOL and with non-Toric IOL. A total of 36 eyes received non-tonic IOL implantation, whereas 44 eyes received toric IOL implantation. There were no statistically significant disparities observed in visual outcome measures and contrast sensitivity between the toric group and the non-toric group. Furthermore, we assessed the predictive preoperative refractive astigmatism (PPRA) and residual refractive astigmatism (RRA) in both cohorts, and no statistical significance was found between the two cohorts (p = 0.08). Twenty-one (53%) patients reported total independence from their glasses at all distances. The mean difference between the predicted and measured refractive error, as calculated by spherical equivalent, was 0.09 D. AcrySof IQ Vivity is a well-tolerated and effective IOL with optimal refractive target for both distant and intermediate vision, needing slight spherical addition for the best near vision. Great questionnaire-based satisfaction was reported by the patients., (© 2024. The Author(s).)

Purpose: People with albinism (PwA) are known to have visual impairments; however, little is known about whether these functions are disrupted across earlier and later stages of the visual pathway. We investigated distinct perceptual functions and fixation stability within each observer and compared the data with age- (±5 years) and sex-matched controls., Methods: Twenty-one self-reported PwA and twenty-one controls were recruited. Angular-indication measurement (AIM) and foraging-interactive-D-prime (FInD) psychophysical methods were deployed to measure OS, OD, and OU near visual acuity, spatial contrast sensitivity function (CSF), temporal contrast sensitivity (tCS; 0.5 c/°; horizontal grating: 0, 1, 2, 4, and 8 Hz), OU glare acuity, threshold-versus-contrast (2c/° vertical grating), long, medium, and short wavelength cone-isolated color detection, color discrimination, stereoacuity across spatial frequencies (1c/°, 2c/°, 4c/°, 8c/°), horizontal, circular, radial pattern and motion coherence, and equivalent-noise motion detection. Thresholds were determined by AIM and FInD and compared using N-ANOVAs, t-tests, planned multi-comparisons, correlations, and unsupervised, agglomerative hierarchical cluster analysis for each group., Results: We found significant differences between groups for most visual functions except for simple and complex form-coherence (two way-ANOVAs, P > 0.05) and complex motion coherence. Correlations between outcomes revealed more significant correlations for PwA and differences in the specific correlates between groups. Unsupervised hierarchical clustering revealed different functional clusters between groups., Conclusions: AIM and FInD successfully interrogated visual deficits in PwA. Overall, PwA showed impaired performance in achromatic, chromatic, temporal, and binocular functions, and had higher intrinsic noise levels. Midlevel vision was comparable between groups. Unsupervised cluster analysis and correlation between outcomes revealed a difference in functional outcome clusters between groups. The results may help to increase the efficiency of screening and identify target deficits for rehabilitation.

Contrast processing is suggested to interact with eye growth and myopia development. A novel contrast-reducing myopia control lens design decreases image contrast and was shown to slow myopia progression. Limited insights exist regarding neural visual processing following adaptation to image contrast reduction. This study investigated foveal neural contrast sensitivity in 29 young adults following a 30-minute adaptation to scattering using a Bangerter occlusion foil 0.8, +0.5-diopter defocus, and a clear lens control condition. Neural contrast sensitivity at its peak sensitivity of 6 cycles per degree was assessed before and after adaptation to the lens conditions, employing a unique interferometric system. Pre-adaptation measurements were averaged from six replicates and post-adaptation measurements by the first and last three of six replicates. The change in neural contrast sensitivity was largest for scattering across the first and last three post-adaptation measurements (+0.05 ± 0.01 logCS and +0.04 ± 0.01 logCS, respectively) compared with control and defocus (all +0.03 ± 0.01 logCS). For scattering, the observed increase of neural contrast sensitivity within the first three measurements differed significantly from the pre-adaptation baseline (p = 0.04) and was significantly higher compared with the control condition (p = 0.04). The sensitivity increases in the control and defocus conditions were not significant (all p > 0.05). As the adaptation effect diminished, no significant differences were found from baseline or between the conditions in the last three measurements (all p > 0.05). When post-adaptation neural contrast sensitivities were clustered into 25-second sequences, a significant effect was observed between the conditions, with only a significant relevant effect between control and scattering at 25 seconds (p = 0.04) and no further significant effects (all p > 0.05). The alteration in neural contrast sensitivity at peak sensitivity was most pronounced following adaptation to the scattering condition compared with defocus and control, suggesting that induced scattering might be considered for myopia control.

The lightness of a surface depends not only on the amount of light reflected off, it but also on the context in which it is embedded. Despite a long history of research, neural correlates of context-dependent lightness perception remain a topic of ongoing debate. Here, we seek to expand on the existing literature by measuring functional magnetic resonance imaging (fMRI) responses to lightness variations induced by the context. During the fMRI experiment, we presented 10 participants with a dynamic stimulus in which either the luminance of a disk or its surround is modulated at four different frequencies ranging from 1 to 8 Hz. Behaviorally, when the surround luminance is modulated at low frequencies, participants perceive an illusory change in the lightness of the disk (lightness induction). In contrast, they perceive little or no induction at higher frequencies. Using this frequency dependence and controlling for long-range responses to border contrast and luminance changes, we found that activity in the primary visual cortex (V1) correlates with lightness induction, providing further evidence for the involvement of V1 in the processing of context-dependent lightness.

Purpose: To determine the acute effect of caffeine intake on the retinal responses as measured with a global-flash multifocal electroretinogram (gfmERG) protocol at different contrast levels., Methods: Twenty-four young adults (age = 23.3 ± 2.4 years) participated in this placebo-controlled, double-masked, balanced crossover study. On two different days, participants orally ingested caffeine (300 mg) or placebo, and retinal responses were recorded 90 minutes later using a gfmERG at three contrast levels (95%, 50%, and 29%). The amplitude response density and peak time of the direct and induced components (direct component [DC] and induced component [IC], respectively) were extracted for five different eccentricities (1.3°, 5.0°, 9.6°, 15.2°, and 21.9°). Axial length, spherical equivalent refraction, habitual caffeine intake, and body weight were considered as continuous covariates., Results: Increased IC amplitude response density was found after caffeine ingestion in comparison to placebo (P = 0.021, ƞp2 = 0.23), specifically for the 95% and 50% stimulus contrasts (P = 0.024 and 0.018, respectively). This effect of caffeine on IC amplitude response density was independent of the retinal eccentricity (P = 0.556). Caffeine had no effect on DC amplitude response density or DC and IC peak times., Conclusions: Our results show that oral caffeine intake increases the inner electro-retinal activity in young adults when viewing stimuli of high- (95%) to medium-contrast (50%). Given the increasing evidence that the inner retinal function is involved in the emmetropization process, these results may suggest that caffeine or its derivatives could potentially play a role in the mechanisms involved in eye growth.

Purpose: To develop a novel classification of highly myopic eyes using artificial intelligence (AI) and investigate its relationship with contrast sensitivity function (CSF) and fundus features., Methods: We enrolled 616 highly myopic eyes of 616 patients. CSF was measured using the quantitative CSF method. Myopic macular degeneration (MMD) was graded according to the International META-PM Classification. Thickness of the macula and peripapillary retinal nerve fiber layer (p-RNFL) were assessed by fundus photography and optical coherence tomography, respectively. Classification was performed by combining CSF and fundus features with principal component analysis and k-means clustering., Results: With 83.35% total variance explained, highly myopic eyes were classified into four AI categories. The percentages of AI categories 1 to 4 were 14.9%, 37.5%, 36.2%, and 11.4%, respectively. Contrast acuity of the eyes in AI category 1 was the highest, which decreased by half in AI category 2. For AI categories 2 to 4, every increase in category led to a decrease of 0.23 logarithm of the minimum angle of resolution in contrast acuity. Compared with those in AI category 1, eyes in AI category 2 presented a higher percentage of MMD2 and thinner temporal p-RNFL. Eyes in AI categories 3 and 4 presented significantly higher percentage of MMD ≥ 3, thinner nasal macular thickness and p-RNFL (P < 0.05). Multivariate regression showed AI category 4 had higher MMD grades and thinner macular compared with AI category 3., Conclusions: We proposed an AI-based classification of highly myopic eyes with clear relevance to visual function and fundus features., Translational Relevance: This classification helps to discover the early hidden visual deficits of highly myopic patients, becoming a useful tool to evaluate the disease comprehensively.