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Perceptual rivalry of ambiguous stimuli reflects the interaction of neural activity among multiple cortical regions. However, it remains unclear what drives a spontaneous perceptual alteration. We hypothesized that increased fluctuations in spontaneous neural activity due to arousal reduction drive the perceptual switch. Here, we show that the pupils shrank a few seconds prior to the onset of the spontaneous perceptual switch. Such pupil constriction was not observed before the exogenous perceptual switch. Pharmacological experiments confirmed that the pupil constriction disappeared when the peripheral parasympathetic pathway (pupil sphincter muscle) was blocked, but it remained intact when the peripheral sympathetic pathway (pupil dilator muscle) was manipulated. Furthermore, rapid pupil dilations with behavioral response are also mediated by the peripheral parasympathetic pathway. The present findings suggested that transient arousal drops, as denoted by the autonomic nervous modulation of pupil size, are involved in inducing the spontaneous perceptual switch of bistable stimuli., (Copyright © 2021 The Authors. Published by Elsevier B.V. All rights reserved.)

Purpose: To report on a second-generation prototype contact lens (modified lens) with enhanced optics to correct coma aberration and compare its performance with that of the prototype contact lens (conventional lens) used to optimise correction of coma aberration in keratoconus (KC)., Methods: Both lenses were designed as a set of standardised soft contact lenses (SCLs) with asymmetric powers along the posterior surface. The modified lens differs from the conventional lens in that the optical zone is decentred superiorly by 0.7 mm. The on-eye performance was compared between the SCLs and no-lens wearing in terms of manifest refraction, corrected distance visual acuity (CDVA), ocular aberrations, subjective quality of vision, and on-eye lens position relative to the pupil., Results: Thirty-four KC eyes were included. SCLs significantly decreased coma aberration compared to no-lens wear (none, 0.68 ± 0.27 μm; conventional lens, 0.37 ± 0.28 μm; modified lens, 0.19 ± 0.15 μm; P < 0.001), with the reduction in coma aberration being significantly greater with the modified lens than with the conventional lens (P = 0.018). No significant difference in manifest refraction or CDVA was found among the three conditions. Quality of vision was significantly better with the modified lens than with no SCL wear (P < 0.05) but no differences were found between the SCLs. The on-eye optical center position relative to the pupil was closer to the pupil centre using the modified lens than the conventional lens (P < 0.001)., Conclusion: Optimisation of the location of the optical zone in a standardised asymmetric SCL improves correction of coma aberrations and on-eye optical centration., (Copyright © 2021 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.)

Retinal prostheses are designed to restore a basic sense of sight to people with profound vision loss. They require a relatively intact posterior visual pathway (optic nerve, lateral geniculate nucleus and visual cortex). Retinal implants are options for people with severe stages of retinal degenerative disease such as retinitis pigmentosa and age-related macular degeneration. There have now been three regulatory-approved retinal prostheses. Over five hundred patients have been implanted globally over the past 15 years. Devices generally provide an improved ability to localize high-contrast objects, navigate, and perform basic orientation tasks. Adverse events have included conjunctival erosion, retinal detachment, loss of light perception, and the need for revision surgery, but are rare. There are also specific device risks, including overstimulation (which could cause damage to the retina) or delamination of implanted components, but these are very unlikely. Current challenges include how to improve visual acuity, enlarge the field-of-view, and reduce a complex visual scene to its most salient components through image processing. This review encompasses the work of over 40 individual research groups who have built devices, developed stimulation strategies, or investigated the basic physiology underpinning retinal prostheses. Current technologies are summarized, along with future challenges that face the field., Competing Interests: Funding and Declaration of Competing Interest LA receives licensing royalties for purchase by commercial entities for the IVI-VLV tool and is supported by a NHMRC Next Generation Fellowship (1151055) and an NHMRC Project Grant (1082358). GD is a consultant to Second Sight Medical Products (USA), and receives licensing royalties for purchase by commercial entities for the ULV-VFQ tool. JW is a consultant to Second Sight Medical Products (USA). BJ is supported by NIH grants R01 EY015128, R01 EY028927, a P30 EY014800 Vision Core Grant and an unrestricted grant from Research to Prevent Blindness to the Moran Eye Center. RH is an employee of Pixium Vision (France). MM is a consultant to Pixium Vision (France) and receives support from the National Institute for Health Research (NIHR) London Biomedical Research Centre (BRC) at Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology. MP and NB receive funding from Bionic Vision Technologies (Australia). DR is supported by the German Ministry for Education and Research, BMBF 031a308., (Copyright © 2019 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.)

Purpose: To determine the vitreous levels of 27 types of cytokines in eyes with retinopathy of prematurity (ROP)., Design: Retrospective case-control study., Participants: Twenty-seven eyes of 19 infants with stage 4 ROP were studied. Six eyes of 5 patients with congenital cataract who underwent lensectomy were used as controls., Methods: The ROP eyes were divided into 2 groups according to vascular activity: 12 eyes with vascularly active ROP and 15 eyes with vascularly inactive ROP. Undiluted vitreous samples were collected, and the vitreous concentrations of 27 types of cytokines were determined by a multiplex bead analysis system: interleukin (IL)-1b, IL-1ra, IL-2, IL-4, IL-5, IL-6, IL-7, IL-8, IL-9, IL-10, IL-12, IL-13, IL-15, IL-17, Eotaxin, fibroblast growth factor (FGF) basic, granulocyte-colony stimulating factor (G-CSF), granulocyte macrophage colony-stimulating factor (GM-CSF), interferon-r, interferon-gamma-inducible protein (IP)-10, monocyte chemoattractant protein 1, macrophage inflammatory protein (MIP)-1a, MIP-1b, platelet-derived growth factor bb, regulated on activation, normal T cell expressed and secreted (RANTES), tumor necrosis factor alpha, and vascular endothelial growth factor (VEGF)., Main Outcome Measures: The vitreous levels of the 27 types of cytokines and a comparison of the levels in the 3 groups., Results: The postmenstrual age at vitrectomy was significantly younger in the vascularly active ROP eyes than in vascularly inactive ROP eyes. The cytokines that had significantly different vitreous levels among the 3 groups were: IL-6, IL-7, IL-10, IL-15, Eotaxin, FGF basic, G-CSF, GM-CSF, IP-10, RANTES, and VEGF (P<0.05). The vitreous levels of IL-6, IL-7, IL-15, Eotaxin, G-CSF, IP-10, and RANTES were significantly higher (P<0.05) in both vascularly active and inactive ROP eyes than in control eyes, whereas the vitreous level of VEGF was significantly higher (P<0.05) only in vascularly active ROP eyes than in control eyes. There was a significantly negative correlation (r = -0.382; P = 0.0495) between the VEGF level and the postmenstrual age at vitrectomy., Conclusions: These results indicate that, although cytokines other than VEGF may be involved in the pathologic changes in eyes with ROP, VEGF is likely to have the strongest correlation with the vascular activity in ROP eyes among these cytokines.

Purpose: To determine the vitreous levels of erythropoietin and vascular endothelial growth factor (VEGF) in eyes with retinopathy of prematurity (ROP) and to study the correlation between the 2 levels., Design: Retrospective case-control study., Participants: Forty eyes of 27 infants with stage 4 ROP (4A, 30 eyes; 4B, 10 eyes) were studied. Five eyes of 4 patients with congenital cataract were used as controls., Methods: The eyes with ROP were classified by the vascular activity into 3 groups: highly vascular-active ROP (n = 16), moderately vascular-active ROP (n = 10), and mildly vascular-active ROP (n = 14). Eyes with highly vascular-active ROP initially received an intravitreal injection of 0.5 mg bevacizumab and underwent vitrectomy approximately 1 week after the injection. The eyes in the other groups underwent vitrectomy without bevacizumab. Undiluted vitreous samples were obtained at the beginning of vitrectomy, and the vitreous concentrations of erythropoietin and VEGF were measured by enzyme-linked immunosorbent assay., Main Outcome Measures: The vitreous concentrations of erythropoietin and VEGF were determined and compared among the 4 groups., Results: The vitreous level of erythropoietin was significantly higher (P<0.05) in the highly and moderately vascular-active ROP eyes than in control eyes. The median concentration of erythropoietin was 744.6 mIU/ml in the highly vascular-active ROP eyes, 729.9 mIU/ml in the moderately vascular-active ROP eyes, 478.0 mIU/ml in the mildly vascular-active ROP eyes, and 0 mIU/ml in control eyes. The vitreous VEGF level was significantly higher (P<0.05) in the moderately vascular-active ROP eyes than in control eyes. The median concentration of VEGF was 44.7 pg/ml in the highly vascular-active ROP eyes that had received an intravitreal bevacizumab injection, 360.8 pg/ml in the moderately vascular-active ROP eyes, 0 pg/ml in the mildly vascular-active ROP eyes, and 11.4 pg/ml in control eyes. There was a significant positive correlation (r = 0.410; P = 0.047) between the erythropoietin and VEGF levels in moderately and mildly vascular-active ROP eyes., Conclusions: The elevated level of erythropoietin and its correlation with the VEGF level in eyes with stage 4 ROP suggest that not only VEGF but also erythropoietin may contribute to the pathogenesis of ROP., Financial Disclosure(s): The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Purpose: To examine highly localized photoreceptor disruptions in the fovea by a high-resolution adaptive optics (AO) fundus camera combined with Fourier-domain optical coherence tomography (FD OCT)., Design: Observational case series., Participants: Three eyes of 3 patients who showed dark foveal spots by slit-lamp biomicroscopy., Methods: Three patients who reported metamorphopsia but showed no changes in the retina in conventional fundus photographs were examined. High-resolution retinal images were obtained with the AO fundus camera and by FD OCT. The images were compared with the findings obtained by standard clinical tests, including Amsler charts and fluorescein angiography (FA)., Main Outcome Measures: Quantitative measurements of the area of photoreceptor disruption., Results: Slit-lamp biomicroscopy revealed an irregularly shaped dark spot in the fovea centralis but no changes in FA in the 3 cases. The photoreceptor mosaic was absent in a highly localized area of the fovea in the images obtained by the AO fundus camera, and the photoreceptor outer segment was absent or disturbed at the corresponding area by FD OCT in all 3 cases. The horizontal and vertical sizes of the area of disturbance of the photoreceptor mosaic in the AO images in the 3 eyes were 400x200 microm, 300x120 microm, and 300x200 microm. These sizes were comparable to the photoreceptor outer segment disturbances in the OCT images which were 330x150 microm, 280x100 microm, 200x150 microm, respectively., Conclusions: Localized OS disturbances were able to be detected in eyes with a dark foveal spot by AO fundus camera 2-dimensionally and by FD OCT axially. The good correspondence of the sizes of the area of photoreceptor disturbances obtained by AO images to those by FD OCT images indicate that the AO images can be used to evaluate and follow the 2-dimensional area of focal changes of the photoreceptors in the fovea quantitatively.

Objective: To compare the ocular wavefront aberrations of normal and keratoconic eyes and to describe the characteristics of the higher-order aberrations in eyes with keratoconus., Design: Prospective case control and observational study., Participants: Thirty-five keratoconic eyes and thirty-eight normal controls., Methods: Higher-order aberrations in refraction were measured with a wavefront sensor, and those aberrations resulting from the cornea were evaluated by videokeratographic data., Main Outcome Measures: Coma-like (S(3 + 5)), spherical-like (S(4 + 6)), and total (S(3 + 4 + 5 + 6)) higher-order aberrations in both refraction and the cornea., Results: The mean +/- standard deviation of S(3 + 5) (1.88 +/- 1.16), S(4 + 6) (0.70 +/- 0.55), and S(3 + 4 + 5 + 6) (2.03 +/- 1.23) in refraction (6-mm diameter, root mean square, micro m) were significantly higher in the keratoconic eyes than in normal controls (0.26 +/- 0.10, 0.19 +/- 0.10, 0.34 +/- 0.11, respectively; Mann-Whitney U test, P = 0.001). Coma-like aberrations were 2.32 times larger than spherical-like aberrations in keratoconic eyes., Conclusions: The increase of ocular higher-order aberrations in keratoconic eyes results from an increase of corneal higher-order aberrations. Coma-like aberrations were dominant compared with spherical-like aberrations in keratoconic eyes. Wavefront sensing will enable us not only to evaluate the quality of vision but also to differentiate keratoconic eyes from normal eyes by analyzing the characteristics of the higher-order aberrations.

Objective: To assess the relation between magnitude of refractive correction and changes in higher order wavefront aberrations of the cornea after laser in situ keratomileusis., Design: Prospective, consecutive, nonrandomized comparative trial (self-controlled)., Participants: One hundred eyes of 53 patients with myopia (-2.0 to -13.0 diopters) were included., Intervention: Laser in situ keratomileusis was performed. Videokeratography measurements were conducted before and 1 month after surgery., Main Outcome Measures: The videokeratography data were used to calculate the higher order wavefront aberrations of the cornea for both small (3 mm) and large (6 mm) pupils., Results: For a 3-mm pupil, the surgery significantly increased coma-like (2.4 +/- 1.3-fold, P < 0.001, paired t test) and spherical-like (1.8 +/- 0.9-fold, P < 0.001) aberrations. For a 6-mm pupil, both coma-like (4.4 +/- 3.3-fold, P < 0.001) and spherical-like (9.4 +/- 5.2-fold, P < 0.001) aberrations were significantly increased by surgery. The amount of achieved correction showed significant correlations with the changes in coma-like (Pearson correlation coefficient r = 0.446, P < 0.001) and spherical-like (r = 0.348, P < 0.001) aberrations for a 3-mm pupil, and coma-like (r = 0.566, P < 0.001) and spherical-like (r = 0.693, P < 0.001) aberrations for a 6-mm pupil. The eyes that lost 2 or more lines of baseline spectacle-corrected visual acuity showed significantly larger induced increases in coma-like (P = 0.003, Mann-Whitney U test) and spherical-like (P = 0.009) aberrations for a 3-mm pupil than those that either improved or remained within 1 line of spectacle-corrected visual acuity, Conclusions: Laser in situ keratomileusis, performed using the current algorithms, increases higher order wavefront aberrations of the cornea, dependent on the amount of refractive correction.

Objective: To examine the anatomic features and surgical indications of familial exudative vitreoretinopathy (FEVR) complicated with rhegmatogenous or tractional retinal detachment., Design: Retrospective noncomparative case series., Participants: Twenty-eight eyes of 25 patients who had either clinically suspected or fully diagnosed FEVR. Of these, 25 had rhegmatogenous retinal detachment, 2 had tractional retinal detachment, and 1 had tractional retinal detachment plus vitreous hemorrhage., Interventions: The authors carefully observed the vitreoretinal interface during surgery, studied the clinical and anatomic features of FEVR, and then evaluated the surgical results., Results: The vitreoretinal adhesions were so strong in the peripheral avascular area that iatrogenic retinal breaks easily occurred in 22 of 28 eyes. In all cases, the bimanual technique with vitreous scissors and forceps was required to dissect the posterior vitreous membrane from the retinal surface. The retina was reattached in 24 of 28 cases (85.7%), and visual acuity improved in 20 eyes (71.4%)., Conclusion: Dissection of the vitreous in the peripheral avascular area is very difficult in FEVR, and those patients for whom this procedure was not successfully performed may have a poorer prognosis.