Background: To assess the safety and efficacy of supracapsular implantation with optic capture of the posterior chamber intraocular lens in Chinese children with aphakic after traumatic cataract.
Methods: It was a retrospective case series study. Fifteen cases (15 eyes) Chinese children received supracapsular implantation with optic capture of the posterior chamber intraocular lens. Pre- and post-operative visual acuities were recorded. Intra- and post-operative complications were observed. The follow-up period ranged from 7 to 43 (28.7±7.2) months.
Results: Implantation of optic capture of the posterior chamber intraocular lens was successfully performed in 15 eyes. The best corrected visual acuity (BCVA) ranged from 0.3 to 1.0 (0.61±0.19). No optic axis opaque was found in 15 eyes with optic capture. The major complications of optic capture were iris posterior synechia and intraocular lens (IOL) precipitates. Intraocular dislocation was found in one case three weeks after the operation.
Conclusions: Supracapsular implantation with optic capture of the posterior chamber intraocular lens is safe and effective for the treatment of traumatic cataract in Chinese children.
Background: To report a new simplified surgical technique to manage small iris coloboma or traumatic iris defect.
Methods: A new surgical technique in which simplified pupilloplasty technique through only a clear corneal paracentesis to manage the iris coloboma or traumatic iris defect within the 120° range was designed. A retrospective revision of the medical records of patients treated with this technique between the years 2013 and 2016 was made. Six eyes of six patients with iris coloboma or traumatic iris defect treated with this new technique were included.
Results: All the operated eyes quickly recovered with central round pupil, negligible complications, inessential symptoms of photophobia and glare, and mild inflammation after a median follow-up time of 22 months (range: 6–34 months).
Conclusions: The simplified pupilloplasty technique presented here could be a good alternative for the management of small iris coloboma or traumatic iris defect.
Abstract: Acute retinal arterial ischemia, which includes transient monocular vision loss (TMVL), branch retinal artery occlusion (BRAO), central retinal artery occlusion (CRAO) and ophthalmic artery occlusion (OAO), is most commonly the consequence of an embolic phenomenon from the ipsilateral carotid artery, heart or aortic arch, leading to partial or complete occlusion of the central retinal artery (CRA) or its branches. Acute retinal arterial ischemia is the ocular equivalent of acute cerebral ischemia and is an ophthalmic and medical emergency. Patients with acute retinal arterial ischemia are at a high risk of having further vascular events, such as subsequent strokes and myocardial infarctions (MIs). Therefore, prompt diagnosis and urgent referral to appropriate specialists and centers is necessary for further work-up (such as brain magnetic resonance imaging with diffusion weighted imaging, vascular imaging, and cardiac monitoring and imaging) and potential treatment of an urgent etiology (e.g., carotid dissection or critical carotid artery stenosis). Since there are no proven, effective treatments to improve visual outcome following permanent retinal arterial ischemia (central or branch retinal artery occlusion), treatment must focus on secondary prevention measures to decrease the likelihood of subsequent ischemic events.
Background: Understanding the neurophysiological mechanisms of Amblyopia, a neurodevelopmental disorder of the visual cortex, will bring us closer to full recovery. Past findings have been contradictory. Results have shown that despite having severe acuity impairment, amblyopes can nonetheless perceive sharp edges. In this study, we explore the representation of blur through a series of image blur-discrimination and matching tasks, to understand more about the amblyopes’ visual system.
Methods: Monocular image blur-discrimination thresholds were measured in a spatial two-alternative forced-choice procedure whereby subjects had to decide which image was the blurriest. Subjects also had to interocularly match pictures that were identical to those used for the image blur discrimination task. Ten amblyopes, as well as a group of ten controls were under study.
Results: Data on amblyopes and controls will be presented for both experiments. According to previous research that was done on blur-edge discrimination and matching, we predict that subjects’ performance will follow a dipper function, that is, all observers will be better at discriminating between both images when a small amount of blur is applied rather than when the image is either sharp or very blurry. We also predict that amblyopes’ blur discrimination will be noisier, but that they will paradoxically be able to match the sharpness of the images presented in the matching task.
Conclusions: This would confirm our hypothesis about amblyopes’ visual system, that they can represent blur levels defined by spatial frequencies that are beyond their resolution limit, and would also raise interesting questions about the visual system in general regarding the different perceptions driven by images versus edges.
Background: In situations where one eye gives a more blurred input to visual processing than the other, the input from the sharper eye tends to dominate the percept. This phenomenon has clinical relevance for monovision treatment, where the two eyes are corrected separately for different distances. We performed a psychophysical investigation of subjects’ ability to identify which of a set of images was blurred in one eye.
Methods: We tested 17 subjects with normal or corrected-to-normal vision. On each trial, subjects viewed an array of four pictures using a monitor with shutter goggles. In the first experiment, three of the pictures were sharp in both eyes (distractors). The fourth picture was sharp in one eye and blurred by a low-pass filter in the other. Subjects identified that odd-one-out target over many trials with different degrees of blur. In the second experiment the target picture was given the same treatment, but the three non-target pictures were made monocular (sharp in one eye, mean grey in the other).
Results: The results from the first experiment with binocular distractors followed our expectations, with subjects showing better performance at detecting more severe blurs. In the second experiment with monocular distractors, we found large individual differences between our observers. Some performed the same as they did in the first condition, others now found the task impossible, and a few performed worse with severe blurs than they did with slight blurs.
Conclusions: Previous studies have reported individual differences in blur suppression, however this study reveals that these differences may depend on the precise details of the judgements being made.
Background: Short-term monocular deprivation has been recently shown to temporarily increase the sensitivity of the patched eye. Many studies have patched subjects for an arbitrary period of 2.5 hours, but for no principled reason. Our goal is to show a relationship, if any, between the length of patching duration and the strength of its effect.
Methods: We tested nine subjects with three different patching durations: 1-, 2-, 3-hour. Four of the nine subjects were patched for 5-hour. Monocular deprivation was achieved by the use of a translucent eyepatch. A session included two rounds of baseline testing of interocular eye balance, patching, and post-patching tests. Each post-patching test occurred at 0, 3, 6, 12, 24, 48, 60 and 96 minutes after patching to track the patching effect over time. Every subject performed two sessions per condition.
Results: One-hour patching produced a small shift in ocular dominance. A larger shift occurred from 2-hour patching, but 3-hour patching produced a comparable effect to the one measured after 2-hour patching.
Conclusions: These results show a saturation of the patching effect beyond 2-hour patching. Hence, we believe that 2-hour patching duration is the optimal duration for eye dominance changes induced by monocular deprivation.
Background: Visual cortex neurons often respond to stimuli very differently on repeated trials. This trial-by-trial variability is known to be correlated among nearby neurons. Our long-term goal is to quantitatively estimate neuronal response variability, using multi-channel local field potential (LFP) data from single trials.
Methods: Acute experiments were performed with anesthetized (Remifentanil, Propofol, nitrous oxide) and paralyzed (Gallamine Triethiodide) cats. Computer-controlled visual stimuli were displayed on a gamma-corrected CRT monitor. For the principal experiment, two kinds of visual stimuli were used: drifting sine-wave gratings, and a uniform mean-luminance gray screen. These two stimuli were each delivered monocularly for 100 sec in a random order, for 10 trials. Multi-unit activity (MUA) and LFP signals were extracted from broadband raw data acquired from Area 17 and 18 using A1X32 linear arrays (NeuroNexus) and the OpenEphys recording system. LFP signal processing was performed using Chronux, an open-source MATLAB toolbox. Current source density (CSD) analysis was performed on responses to briefly flashed full-field stimuli using the MATLAB toolbox, CSDplotter. The common response variability (global noise) of MUA was estimated using the model proposed by Scholvinck et al. [2015].
Results: On different trials, a given neuron responded with different firing to the same visual stimuli. Within one trial, a neuron’s firing rate also fluctuated across successive cycles of a drifting grating. When the animal was given extra anesthesia, neurons fired in a desynchronized pattern; with lighter levels of anesthesia, neuronal firing because more synchronized. By examining the cross-correlations of LFP signals recorded from different cortical layers, we found LFP signals could be divided to two groups: those recorded in layer IV and above, and those from layers V and VI. Within each group, LFP signals recorded by different channels are highly correlated. These two groups were observed in lighter and deeper anesthetized animals, also in sine-wave and uniform gray stimulus conditions. We also investigated correlations between LFP signals and global noise. Power in the LFP beta band was highly correlated with global noise, when animals were in deeper anesthesia.
Conclusions: Brain states contribute to variations in neuronal responses. Raw LFP correlation results suggest that we should analyze LFP data according to their laminar organization. Correlation of low-frequency LFP under deeper anesthesia with global noise gives us some insight to predict noise from single-trial data, and we hope to extend this analysis to lighter anesthesia in the future.
Background: To investigate and analyze the hospitalization costs of inpatients with primary acute angle closure glaucoma (PACG), and to explores the influencing factors of hospitalization cost and to provide reference for specialized hospitals to carry out clinical pathways.
Methods: The first page diagnostic data of PACG patients’ medical records were collected, and an Excel database was established according to the International Classification of Diseases (ICD-10) code. Statistical analysis of hospitalization data was performed using SPSS 17.0 software.
Results: Hospitalization days and clinical pathway which affect the change of the hospitalization cost (P<0.001).
Conclusions: Hospitalization day is an important factor affecting the hospitalization cost, reducing unnecessary hospitalization time can control the increase of hospitalization cost.
Abstract: Advances in intraocular lens (IOL) design have rendered cataract surgery a refractive procedure. Newer IOL types include bifocal, trifocal and extended depth of focus (EDOF) IOLs. Their basic difference nestles in the number of focal points that each lens provides, which in turn leads to different visual outcomes. Familiarity of surgeons with the various characteristics of each lens is of utmost importance for accurate IOL selection to match each patient’s needs. In this review, we aim to compare the clinical outcomes after implantation of multifocal and EDOF IOLs in terms of distance, intermediate and near vision, contrast sensitivity, and reading performance. Finally, we discuss the defocus curve and the optical and photic phenomena associated with each type of IOL.
