Strabismus
Strabismus is a condition where the eyes do not align properly. Explore strabismus research studies to find new options.
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Found 83 Actively Recruiting clinical trials
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The transient diplopias (TD) is defined by a short diplopia. Their etiology may be ophthalmological, neurological non-ischemic or of ischemic origin. The difficulty is to recognize an ischemic mechanism which imposes emergency cares. A clinical score could help the clinician to recognize the etiology of the TD .
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At an enrollment visit, distance VA will be measured in trial frames with or without cycloplegia based on a cycloplegic refraction performed within 30 days. If still apparently eligible, children will be prescribed spectacles and will then return for a spectacle baseline visit, where they will wear their new spectacles for the first time for at least 10 minutes (but no more than 24 hours) and will be tested in those new spectacles to confirm final eligibility prior to randomization. Participants not found to be eligible in their new spectacles will end study participation. Participants eligible for the study will be randomly allocated to one of two treatment groups: Sequential (spectacles alone) and then patching if needed (monitored by ODM), or Simultaneous (spectacles and patching monitored by ODM). After randomization, follow-up visits will occur at 8-week intervals through 56 weeks. At each visit on or after the 8-week visit, participants will be classified as either: stable/worsening or improving; those stable/worsening are then classified as having either resolved or residual amblyopia, provided that the current and most recent previous visit were completed at least 6-weeks apart (target 8 weeks) and provided the required test and retest VA testing was completed. Participants who are stable/worsening and have residual amblyopia in the sequential group will start patching (monitored by ODM) and continue to be followed every 8 weeks. Participants in the simultaneous group, or in the sequential group after having advanced to patching, who are stable/worsening but have residual amblyopia will be released to treatment at investigator discretion. All participants continue 8-weekly visits until 56 weeks when Study participation ends.
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The prevalence of myopia in the world has exceeded 25% and is increasing year by year. Asia, especially China, is an area with high incidence of myopia. It is reported that the prevalence of myopia in children and adolescents in China was 53.6% in 2018. Low concentration atropine eye drops is one of the effective means to slow the progression of myopia. At present, low concentration atropine eye drops have been widely used in China, but its long-term efficacy and possible side effects still need to be studied. Atropine is a non-selective muscarinic acetylcholine (M) receptor antagonist that paralyzes the ciliary muscle, dilates the pupil, and reduces the power of accommodation. Current studies have confirmed the effect of low concentrations of atropine drops in slowing the progression of myopia. In the ATOM2 study, there was a rapid and dose-dependent decrease in accommodation after atropine drops: after 2 weeks of use, accommodation decreased from baseline 16.2D to 11.3D (4.9D) in the 0.01% atropine drops group, from baseline 16.7D to 3.8D (12.9D) in the 0.1% atropine group, and from baseline 15.8 D to 2.2 D (13.6 D) in the 0.5% atropine group; after 1 year of discontinuation, there was some recovery of the accommodation in all the three groups, but it was still lower than the baseline values for each group, with a mean decrease of 2.56 D. Similar results were found in the LAMP study by Janson C. Yam, 0.05% atropine drops reduced the accommodation by approximately 2D on average after 1 year of treatment. In general, if accommodation decreases by 2D or more compared to normal values, accommodation insufficiency is considered. There is a linkage between accommodation and convergence, therefore the decrease of accommodation will also affect the binocular vision. Above all, the effect of atropine eye drops on pupil size, near visual acuity, amplitude of accommodation which is still impaired after 1 years' withdrawal, make us have many concerns and doubts about indications of atropine eye drops in children with strabismus or after the strabismus surgery. Strabismus is a common eye disease in children, with an incidence rate of about 3%. It is reported that about 72% of strabismus cases in Asia are exotropia, of which intermittent exotropia is the most common type, and most cases are accompanied with myopia. It is found that patients with intermittent exotropia are often associated with abnormal accommodation. Ha SG reported that the amount of accommodation required to maintain binocular fusion in patients with intermittent exotropia was greater than that of normal controls. In addition, pupil size and visual clarity are also factors affecting accommodation. In conclusion, atropine eye drops may affect the occurrence and development of intermittent exotropia by reducing the amplitude of accommodation, dilating pupils and blurred near vision. At the same time, the reduction of accommodation causes poor focusing and inappropriate afferent signals of the convergence system, which will lead to the fatigue of the convergence and divergence system, which may affect the ocular alignment of exotropia after surgery. In most cases, the reduced accommodation and convergence might induce exotropia, but in some patients, they may use more accommodative stimuli to compensate the insufficiency of accommodation, and there may be an increase in convergence or even esotropia. In general, in China, myopia with exotropia or exophoria is a high incidence of eye disease in children, and low concentration atropine eye drops have been widely used to control the progression of myopia. It is urgent to carry out a large sample randomized controlled clinical trial to evaluate the impact of low concentration atropine on the ocular alignment and binocular vision of patients with exotropia and exophoria, and guide much safer application of the low concentration atropine eye drops.
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Healthy Volunteer
Amblyopia (lazy eye) is a developmental vision disorder in which the brain doesn't efficiently process images from one eye and which over time causes decreased vision in that eye. Early detection and early treatment, by age 7 years, are effective in reducing the burden of amblyopia. There is evidence from randomized clinical trials (RCTs) that 73-90% of amblyopic children in this age range treated with glasses and patching, the most commonly prescribed treatments for amblyopia, have improvements in visual acuity. More recently, binocular amblyopia treatments show similar effectiveness to patching in children \<7 years old. Yet, full recovery of normal visual acuity occurs in only 30-40% of children regardless of treatment approach; most amblyopic children have residual amblyopia post-treatment at age 8-12 years, when there is little or no benefit of additional or other standard-of care treatments. It is important investigate novel treatments for amblyopia in older children because the vision deficits in persistent residual amblyopia also have associated knock-on effects, including slow reading and impaired motor skills in natural binocular viewing conditions, diminished self-perception and reduced quality of life. Failure to detect and remediate amblyopia during childhood typically results in lifelong deficits and doubles the lifelong risk of visual impairment in the fellow eye. To address this need, we will conduct a pilot study to investigate whether the novel Curesight™ is effective in treating amblyopia in older children aged 8 to 12 years. CureSight™ is an eye-tracking based system designed to treat amblyopia under dichoptic conditions that incorporates eye-tracking and separation of streamed visual stimuli presented on a tablet into 2 separate digital channels, one for each eye . The treatment task consists of passively watching streamed video content presented by the system according to the child's personal preference from the web links approved by the parents. The main components of the system include : (1) a an 11.6-inch tablet for viewing the videos (2) an eye tracker bar placed below the tablet that tracks each eye's gaze position, (3) anaglyph (red-cyan) glasses worn while watching videos to separate stimuli presented to each eye and (4) proprietary software that uses the eye-tracking data to blur the central vision area of the visual stimuli presented to the fellow eye to encourage the brain to use the sharp, high resolution information from the amblyopic eye's center of vision. The diameter and magnitude of the blur are adjusted automatically during treatment according to the visual of each eye, as measured at follow-up visits, entered on the CureSight™ cloud portal (Health Insurance Portability and Accountability Act and General Data Protection Regulation compliant). Worse amblyopic eye visual acuity and larger differences in visual acuity between eyes result in more blur and greater diameter of blur. The Curesight™ device received Food and Drug Administration clearance (identifier, K221375; September 29, 2022; uploaded with this IRB application), indicated for improvement in visual acuity and stereo acuity in amblyopia patients, aged 4 - \<9 years, associated with anisometropia and/or with mild strabismus. This approval was based on data from a pilot study and a multi-center randomized clinical trial conducted with children aged 4 to 8 years.25,26 However, very few children older than age 7 years were included so the effectiveness of Curesight™ treatment for children aged 8 to 12 is unknown. Our pilot study will evaluate response to the Curesight™ treatment in this older age range.
RECRUITING
BACKGROUNDS Nowadays, phacoemulsification for cataract treatment is the most common surgical procedure performed and anesthetics procedure has been shifted from retrobulbar or peribulbar anesthesia to topical anesthesia (TA). Phacoemulsification under TA proved to be a safe and low risk procedure with the incidence of adverse events requiring medical emergency team interventions to be 0.04%. However, it is not uncommon that patients can suffer from pain, anxiety and unpleasant visual sensation during this procedure. Complementary sedation has long been thought to alleviate the anxiety and pain of the patient during surgery with local anesthesia. Studies revealed that approximately one fourth of the patients underwent phacoemulsification under TA or retrobulbar anesthesia requested additional intravenous sedation of midazolam. \[8\] However, the intravenous sedation, such as midazolam, propofol, or etomidate, increase the risk of additional anesthetic complications of heart rate, blood pressure, body temperature, and nausea, \[9,10\] and therefore, anesthesia monitoring was mandatory during the surgery. Compared with intravenous sedation, oral sedation is less costly and less invasive. Studies with different oral sedation agents revealed different effects. In the study of 41 patients serving themselves as control, patients reported more pain and photophobia in the surgery with TA alone than the other with midazolam syrup and oral transmucosal fentanyl citrate. However, two studies comparing oral diazepam or triazolam with intravenous midazolam showed similar rates of anxiety and pain or noninferior satisfaction. Moreover, the randomized control trial containing 50 procedures in each groups revealed that patients received TA alone during phacoemulsification reported similar pain or anxiety level to those received complementary intravenous midazolam. Despite the abundant results from above, nearly 40% patients reported moderate to extremely anxiety during phacoemulsification under TA, and approximate 7% of patients rated themselves extreme anxiety or were diagnosed as anxiety. A simple comparison between with or without complementary sedation for general patients underwent phacoemulsification with TA is merely not enough. Further investigations to reduce the anxiety experienced during phacoemulsification with TA according to patients' characteristics is therefore mandatory. Previous studies had showed that patients with higher level of trait anxiety reported higher anxiety response for a stressful situation. Preoperative anxiety levels were also reported to be a significant predictor of pain experience during phacoemulsification with TA. The need for complementary sedation could be different in patients with different trait anxiety. Furthermore, different severity levels of anxiety and pain were experienced during the first and second eye surgery. Therefore, in this study, the investigators will investigate the trait anxiety of patients planned for phacoemulsification under TA and its effect on their anesthetic satisfaction with complementary oral sedation. The investigators will also analysis the anxiety and pain experienced in the first and second eye phacoemulsification in patients with different levels of trait anxiety. The investigators choose alprazolam as the oral sedative. It was reported to have a shorter half-life and less side effects of drowsiness and lightheadedness than diazepam used in previous studies.
RECRUITING
Poor compliance, limited improvement of visual functions, and regression after recovery of visual acuity have been observed in the management of amblyopia using conventional patching. Recently, dichoptic/binocular digital therapy has been developed, but no widely accepted binocular treatments with superiority available for children and adults with amblyopia (Pineles et al., 2020; Oscar et al., 2023). Here, we designed an innovative binocular therapy using augmented reality (AR) training, based on neural deficits in amblyopia, to achieve better outcomes. Selective deficits were found in the parvocellular pathway (P pathway) compared to the magnocellular pathway (M pathway) in the monocular processing of visual information in the amblyopic eye (AE) (Wen et al., 2021). In addition to monocular deficits, imbalanced binocular suppression may also play important roles in the visual deficits of amblyopia as suggested by clinical evidence (DeSantis, 2014; Von Noorden, 1996) and psychophysical studies (Baker et al., 2008; Holopigian et al., 1988; Li et al., 2011; Zhou et al., 2013). Based on the neural deficits in unilateral amblyopia, we first apply the push-pull approach (Xu, He \& Ooi, 2010; Ooi et al., 2013), which was aimed to reduce sensory eye dominance in previous literatures, into the rebalance of functions of M and P pathways in the AE and the rebalance of binocular interaction, to improve the high spatial detail perception of the AE in daily life under binocular viewing condition, as well as binocular functions. Using AR technique combined with dichoptic device, we present differentially-processed images to each eye of the patients in real time, allowing them to interact with the surrounding environment during the visual training. Using a Butterworth filter with the cutoff at 2 cycle pre degree, the images captured in real time are divided into information with high and low spatial frequencies (SFs) corresponding to the P and M pathways, respectively. For the AE, original low SF phase of captured images is scrambled into random noise with the refresh rate of the display, while the original information with high SF is retained completely. As a result, the function of the P pathway is pulled while the function of the M pathway is pushed, actively encouraging the interaction with the surrounding environment through high SF information. For the fellow eye (FE), original high SF phase of captured images is scrambled into random noise with increased contrast and reduced temporal frequency, while the contrast of the original high SF information is reduced. As a result, in addition to the push-pull in monocular P\&M pathways, the function of the P pathway in the FE is pulled and while the function of the P pathway in the AE is pushed, actively improving the rebalance of binocular inhibition. The proposed trial will be conducted in 4 different study sites in China. For the AR training group, patients need to perform AR training for 2 hours per day at home. For the patching group, patients need to patch the FE for 2 hours per day at home.
RECRUITING
Patients belonging to the UOC Ophthalmology, the UOS Diagnosis and Treatment of Ocular Motility Disorders and the Pediatric Ophthalmology Outpatient Clinic, Fondazione Policlinico Universitario A. Gemelli IRCCS in Rome who meet the inclusion criteria will be recruited. Patients will be divided into two groups according to the nature of strabismus (congenital or acquired). All patients, regardless of the nature of strabismus, will undergo a complete ophthalmologic and orthoptic examination and balance examination before strabismus surgery (baseline, T0), at 30 days after surgery (T1), at 90 days after surgery (T2), and at 180 days after surgery (T3). All patients will undergo clinical evaluation and assessment of balance and fall risk at all assessment timepoints
RECRUITING
To date, all studies of contrast-rebalanced binocular amblyopia treatment games used the same 10% per day contrast-increment that was designed for short-term intervention studies lasting 1-4 weeks; i.e., after 18 days of successful game play, both eyes viewed 100% contrast (no contrast-rebalancing).This study will investigate two alternative protocols designed to extend the game treatment period beyond 4 weeks to allow for more complete recovery of visual acuity. The new protocols will be compared with the original 10% contrast-increment game protocol in an 8-week 3-arm RCT to determine whether one or both of the new protocols is more effective than the current 10% increment. Based on pilot data, we expect about 40% of amblyopic children to achieve normal visual acuity in 8 weeks. In an effort to also promote recovery of binocular vision, children who attain ≤0.4 logMAR at 8 weeks will be enrolled in stereoacuity training at the 8-week visit for the next 4 weeks. Children with residual amblyopia (BCVA \>0.4 logMAR) at the 8-week visit will be provided with dichoptic movies for additional amblyopia treatment for another 4 weeks.
RECRUITING
The objective of this study is to determine if the binocular visual therapy with red-green glasses and the use of electronic devices is effective for amblyopia treatment in children. Participants will be randomly assigned to one of three treatment modalities: Group A: eye patch on the fellow eye and to near-vision activities (such as reading, drawing, etc) Group B: an eye patch on the fellow eye and a electronic tablet Group C: red/green glasses and a electronic tablet Treatment will be done buy the three groups daily during 2 consecutive hours, and will be completed for four months. Children will then suspend the therapy for 2 months, and will be reevaluated to determine lazy eye relapses . All groups will be compared to see which patients achieved greater improvement on visual acuity and depth perception.
RECRUITING
Background: Infantile idiopathic nystagmus (IIN) or congenital motor nystagmus is most common among infantile nystagmus cases. It has a characteristic waveform eye movement pattern with an exponentially increasing velocity slow-phase followed by a saccadic fast phase. IIN is present from infancy but usually recognized few months into life and may even be evident only after the child has reached several years of age. Characteristics of IIN include the following: conjugate eye movements with equal frequency and amplitude in each eye, gaze position does not change the direction of fast phase, a null point may be present with less motor instability, convergence achieves better motor stability, head turn and head tilt present to facilitate viewing at null point and absence of oscillopsia in most cases. When the patient is asymptomatic no treatment is required. However, if the visual acuity is decreased with abnormal head posture and oscillopsia interventions are warranted. Traditional used therapies include muscle surgery, optical devices, drugs and botulinum toxin injections. All current available therapies aim at changing the functional balance among eye muscles responsible for eye movements with hope that they will produce better ocular stability and better foveation time for incoming images with better vision. All such cases also require Low Vision Rehabilitation interventions to improve functional vision and Quality of Life. Rationale for the study: Active eye movement control training, an old and still most prevalent intervention in low vision rehabilitation (LVR) was never used in nystagmus cases with low vision for various reasons. One of them was the inability to document accurately eye movements and fixation characteristics in patients with low vision, nystagmus cases included. Biofeedback training (BT) is the latest and newest technique for oculomotor control training in cases with low vision when using available modules in the new microperimetry instruments. Sporadic reports in the literature highlighted positive benefits from using BT in a variety of nystagmus cases. The purpose of this study is to assess systematically the impact of BT in a series of cases with IIN and formulate guidelines for further use of this intervention in nystagmus cases in general. Study hypothesis The visual and audio parts of the BT program improve in a synergistic way oculomotor control through attention improvement and volitional eye movements towards pre-designated targets. Improved oculomotor control results in better fixation stability of eyes. Better fixation stability in turn results in better vision for distance and near. Dual sensory BT is a therapy used in low vision for more than ten years, showing good results for near and distance vision in cases with macular degeneration and other pathologies. The study hypothesis, never tested before, is that BT in cases with IIN will impact positively oculomotor control and visual acuity as it was proven to do in cases with macular degeneration. Significance of the study: Most cases with IIN suffer also from poor visual acuity and in essence are visually impaired. Where as in cases with visual impairment near vision can be easily improved to functional levels using magnification in spectacle glasses, distance vision cannot be improved further with spectacle glasses and other low vision devices are required. BT in IIN cases may result in significant improvement in visual abilities for distance in a similar way that BT results in improved distance vision in cases with macular degeneration. Clinical trial design: This is prospective clinical randomized trial to include a control group and take place over a period of up to 24 months. The objectives set for this trial is to verify if BT impacts on oculomotor control in cases with IIN and results in better distance visual acuity in those trained with BT. Clinical trial population: The intended population for this clinical trial is to be found among the Low Vision Rehabilitation (LVR) clinical practice patients. Patients will be considered for inclusion into the study if they meet the trial entry criteria. The following is an overview of the study procedures: following obtaining consent from study participants, confirmation of eligibility, and baseline assessments (Visit1, V1), participants will undergo 4 BT sessions (V2, V3, V4 and V5). Upon completion of the 4 BT sessions participants will return for a follow up after 1 week (V6) and 3 months (V7). Baseline procedures During the baseline visit (Visit 1) participants will be assessed for Best Corrected Visual Acuity (BCVA) for distance vision with ETDRS charts at 4 meters, preferred retinal locus (PRL) characteristics, fixation stability (FS) estimates and nystagmus amplitude with the MAIA microperimeter (Centervue, Padova, Italy). Participants will be assessed also for near vision and contrast sensitivity measured with the 2 contrast levels Colenbrander chart, stereopsis will be assessed with the Frisby Stereo Test and Quality of Life estimates will be assessed with the children's visual function questionnaire (CVFQ). This visit may take an hour time. Training procedure during training procedure visits (V2-5) the participant is seated in front of the instrument while visual targets are presented to the eye and auditory stimuli are presented in tandem with the visual stimuli. Patient has to identify targets and respond by pressing a button. BT includes 4 BT attempts of 5 minutes each with 5 minutes rest time between each attempt. The procedure involves presentation of a standard LED fixation target (FT) consisting of a small red circle of about 0.76° diameter. A fixation training target (FTT) will be selected by the trainer at a perceived better fixation point. Initially the participant will be instructed to stare at the FT circle. Following this stage, the participant will be guided to look in the direction of the FTT and listen simultaneously to the audio feedback. As performing this task, the participant will actively control the eye movements until the audio feedback becomes more frequent and then becomes a continuous sound pattern. This continuous sound will signalize to the patient is controlling nystagmus. Simulated BT includes presentation of a C10-2 microperimetry program. The procedure involves presentation of a standard LED fixation target (FT) consisting of a small red circle of about 0.76° diameter. Initially the participant will be instructed to stare at the FT circle. Following this stage, the participant will be guided to look at the FT and simultaneously to be aware of any flashing lights in the periphery of vision. As performing this task, the participant will actively control the eye movements and similar to computer games, the patient has to identify targets in the peripheral field of vision and respond by pressing a button. Participants will be given take-home efficiency reading exercises. Training visits are repeated to a total of 4 on a weekly interval. End of study procedures Additional follow up Visits 6 and 7 will take place at 5 weeks and 4 months following visit 1. Participants will be assessed also for near vision and contrast sensitivity measured with the 2 contrast levels Colenbrander chart, stereopsis will be assessed with the Frisby Stereo Test and Quality of Life estimates will be assessed with the children's visual function questionnaire (CVFQ). There are no known risks or side effects known from using biofeedback training. In some cases, perceived side effects observed are general fatigue, tiredness due to the efforts to fixate, discomfort or eye strain.
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