BACKGROUND: Persistent hyperplastic primary vitreous (PHPV) is a rare congenital developmental ocular disorder caused by incomplete regression of the embryonic hyaloid vasculature. Here we report a case of nonsurgical unilateral anterior PHPV that was managed by amblyopia treatment and resulted in an improvement of visual acuity and regression of the fetal vasculature.
METHODS: A three-year-old girl was diagnosed with unilateral anterior PHPV in the left eye, manifested with posterior pole cataract, posterior capsule opacification, tunica vasculosa lentis, and a floating hyaloid artery connected to the retrolental mass. The plaque was not large enough to fill the pupil, and conservative management along with amblyopia treatment was conducted. Nineteen months later, the visual acuity in the affected eye improved from 20/100 to 20/50 with correction, and the fetal vasculature regressed gradually and finally into a nonperfusion ghost vessel.
CONCLUSIONS: In PHPV-affected children, regression of the fetal vasculature may be observed, and conservative management and amblyopia treatment may be helpful for visual improvement.

Purpose: To demonstrate the therapeutic benefit of extended wear bandage contact lens (BCL) use in patients with epidermolysis bullosa (EB) suffering from recurrent, painful, and slow-to-heal corneal epithelial defects.Methods: Case reports of three patients.Results: We report ophthalmic treatment of three pediatric patients, two with recessive dystrophic EB (RDEB) and one with junctional EB (JEB), who suffered frequently recurrent corneal abrasions and were treated with 30-day extended-wear bandage contact lenses (BCLs), replaced every month for at least 1 year. Pain and frequency of corneal abrasions improved immediately, and the BCLs were well tolerated. Vision was maintained or improved in all cases. Corneal ulcers did not occur while on antibiotic prophylaxis.Conclusions: Continuous and prolonged BCL therapy in patients with EB can be an effective way to immediately alleviate pain, prevent recurrent abrasions, and improve patient quality of life.

OBJECTIVE: Available pharmacological treatment of mania is insufficient. Virtual darkness therapy (blue light-blocking treatment by means of orange-tinted glasses) is a promising new treatment option for mania. The basis for this might be the recently identified blue light-sensitive retinal photoreceptor, which is solely responsible for light stimulus to the circadian master clock. This is the first case report describing the clinical course of a closely monitored, hospitalized patient in a manic episode first receiving clear-lensed, and then blue light-blocking glasses.
METHODS: A 58-year-old Caucasian man, with bipolar I disorder and three previous manic episodes, was hospitalized during a manic episode. In addition to pharmacological treatment, he was treated with clear-lensed glasses for seven days, then one day without glasses, followed by six days of blue light-blocking glasses. During the entire observational period, he wore an actigraph with internal light sensors.
RESULTS: Manic symptoms were unaltered during the first seven days. The transition to the blue-blocking regime was followed by a rapid and sustained decline in manic symptoms accompanied by a reduction in total sleep, a reduction in motor activity during sleep intervals, and markedly increased regularity of sleep intervals. The patient\'s total length of hospital stay was 20 days shorter than the average time during his previous manic episodes.
CONCLUSIONS: The unusually rapid decline in symptoms, accompanied by uniform sleep parameter changes toward markedly increased regularity, suggest that blue-blockers might be targeting a central mechanism in the pathophysiology of mania that needs to be explored both in clinical research and in basic science.

Although amblyopia typically manifests itself as a monocular condition, its origin has long been linked to unbalanced neural signals from the two eyes during early postnatal development, a view confirmed by studies conducted on animal models in the last 50 years. Despite recognition of its binocular origin, treatment of amblyopia continues to be dominated by a period of patching of the non-amblyopic eye that necessarily hinders binocular co-operation. This review summarizes evidence from three lines of investigation conducted on an animal model of deprivation amblyopia to support the thesis that treatment of amblyopia should instead focus upon procedures that promote and enhance binocular co-operation. First, experiments with mixed daily visual experience in which episodes of abnormal visual input were pitted against normal binocular exposure revealed that short exposures of the latter offset much longer periods of abnormal input to allow normal development of visual acuity in both eyes. Second, experiments on the use of part-time patching revealed that purposeful introduction of episodes of binocular vision each day could be very beneficial. Periods of binocular exposure that represented 30-50% of the daily visual exposure included with daily occlusion of the non-amblyopic could allow recovery of normal vision in the amblyopic eye. Third, very recent experiments demonstrate that a short 10 day period of total darkness can promote very fast and complete recovery of visual acuity in the amblyopic eye of kittens and may represent an example of a class of artificial environments that have similar beneficial effects. Finally, an approach is described to allow timing of events in kitten and human visual system development to be scaled to optimize the ages for therapeutic interventions.

OBJECTIVE: The aims of this study were to assess (1) the relationship between interocular suppression and visual function in patients with anisometropic amblyopia, (2) whether suppression can be simulated in matched controls using monocular defocus or neutral density filters, (3) the effects of spectacle or rigid gas-permeable contact lens correction on suppression in patients with anisometropic amblyopia, and (4) the relationship between interocular suppression and outcomes of occlusion therapy.
METHODS: Case-control study (aims 1-3) and cohort study (aim 4).
METHODS: Forty-five participants with anisometropic amblyopia and 45 matched controls (mean age, 8.8 years for both groups).
METHODS: Interocular suppression was assessed using Bagolini striated lenses, neutral density filters, and an objective psychophysical technique that measures the amount of contrast imbalance between the 2 eyes that is required to overcome suppression (dichoptic motion coherence thresholds). Visual acuity was assessed using a logarithm minimum angle of resolution tumbling E chart and stereopsis using the Randot preschool test.
METHODS: Interocular suppression assessed using dichoptic motion coherence thresholds.
RESULTS: Patients exhibited significantly stronger suppression than controls, and stronger suppression was correlated significantly with poorer visual acuity in amblyopic eyes. Reducing monocular acuity in controls to match that of cases using neutral density filters (luminance reduction) resulted in levels of interocular suppression comparable with that in patients. This was not the case for monocular defocus (optical blur). Rigid gas-permeable contact lens correction resulted in less suppression than spectacle correction, and stronger suppression was associated with poorer outcomes after occlusion therapy.
CONCLUSIONS: Interocular suppression plays a key role in the visual deficits associated with anisometropic amblyopia and can be simulated in controls by inducing a luminance difference between the eyes. Accurate quantification of suppression using the dichoptic motion coherence threshold technique may provide useful information for the management and treatment of anisometropic amblyopia.
BACKGROUND: Proprietary or commercial disclosure may be found after the references.

Visual stress is a condition characterised by symptoms of eyestrain, headaches and distortions of visual perception when reading text. The symptoms are frequently alleviated with spectral filters and precision tinted ophthalmic lenses. Visual stress is thought to arise due to cortical hyperexcitability and is associated with a range of neurological conditions. Cortical hyperexcitability is known to occur following stroke. The case presented describes visual stress symptoms resulting from stroke, subsequently managed with spectral filters and precision tinted ophthalmic lenses. The case also highlights that the spectral properties of the tint may need to be modified if the disease course alters.

It is well established that refractive development is regulated by visual feedback. However, most optical treatment strategies designed to reduce myopia progression have not produced the desired results, primarily because some of our assumptions concerning the operating characteristics of the vision-dependent mechanisms that regulate refractive development have been incorrect. In particular, because of the prominence of central vision in primates, it has generally been assumed that signals from the fovea determine the effects of vision on refractive development. However, experiments in laboratory animals demonstrate that ocular growth and emmetropization are mediated by local retinal mechanisms and that foveal vision is not essential for many vision-dependent aspects of refractive development. However, the peripheral retina, in isolation, can effectively regulate emmetropization and mediate many of the effects of vision on the eye\'s refractive status. Moreover, when there are conflicting visual signals between the fovea and the periphery, peripheral vision can dominate refractive development. The overall pattern of results suggests that optical treatment strategies for myopia that take into account the effects of peripheral vision are likely to be more successful than strategies that effectively manipulate only central vision.

Charles Bonnet first described visual hallucinations in a ground of visual deprivation in the 18th century. In this paper, two case reports with the syndrome are presented (female 83 years old, male 68 years old) along with a short literature review. The distinction of the syndrome from other psychiatric disorders (delirium, dementia), where visual hallucinations are also present, demands the presence of the diagnostical triad: visual hallucinations, visual impairment, intact cognitive status. The hallucinations are rich in colors and tension, people usually have the \"leading roles\" and patients mostly are curious, enjoy the hallucinations and are not afraid of them. More often hallucinations appear after acute visual impairment and in older patients. There are several theories concerning the mechanisms that lead to the syndrome. The Charles Bonnet syndrome appears to be self-restricted and there are no clear guidelines regarding its treatment.

In immersive virtual environments, judgments of perceived egocentric distance are significantly underestimated, as compared with accurate performance in the real world. Two experiments assessed the influence of graphics quality on two distinct estimates of distance, a visually directed walking task and verbal reports. Experiment 1 demonstrated a similar underestimation of distances walked to previously viewed targets in both low- and high-quality virtual classrooms. In Experiment 2, participants\' verbal judgments underestimated target distances in both graphics quality environments but were more accurate in the high-quality environment, consistent with the subjective impression that high-quality environments seem larger. Contrary to previous results, we suggest that quality of graphics does influence judgments of distance, but only for verbal reports. This behavioral dissociation has implications beyond the context of virtual environments and may reflect a differential use of cues and context for verbal reports and visually directed walking.

Latent nystagmus (LN) and manifest latent nystagmus (MLN) are closely associated with early visual deprivation and strabismus. In both cases, the eyes oscillate horizontally in an involuntary manner and the fast phases always beat towards the attending or fixing eye. By simultaneously recording eye movements during the dichoptic viewing of dissimilar visual stimuli we present evidence that MLN offers a unique opportunity to examine the nature of sensori-motor switching. In particular, we show how the nystagmus beat direction is strongly influenced by endogenous and exogenous attention. A model describing the possible mechanisms underpinning the sensori-motor switching is proposed.