Strabismus最新文献

Introduction: Is Intermittent Exotropia being conceived and treated as an ocular-mechanical problem? Is etiology taken into account when planning for intervention? Which success criteria are used? Are they based on alignment or do they also consider visual function? In order to answer these questions, a review of studies assessing the outcomes of strabismus surgery in Intermittent Exotropia has been conducted. Methods: published between January 2003 and December 2023 were included. The database searched was MEDLINE following a predefined protocol. In addition to electronic database searches, manual searches were carried out and experts contacted. A total of 102 studies comprising 12 974 participants were included in this review. Results: Possible strabismus etiology was not stated in 91.2% of the studies. The underlying causes of the deviation were not taken into account for treatment consideration in any of the studies. Criteria for surgical success was based solely on ocular alignment (82.4%) and only 10 studies (9.8%) defined successful surgery with both motor and sensory criteria. Thirty-four different definitions of successful ocular alignment were identified. Discussion: In conclusion, Intermittent exotropia etiology is omitted in studies assessing surgical outcomes. The possible causes of the deviation are not taken into account when deciding on the type of surgery and are rarely mentioned. In most studies, the criteria for surgical success is based solely on eye alignment, independently of visual function and control.

Introduction: Aberrant regeneration of the third nerve is a known entity after trauma. It is important to recognize signs of aberrant regeneration and keep lid aperture disparity in mind before choosing the surgical procedure in such cases. Surgical procedure in these cases is often customized on case-to-case basis. Methods: Two cases with combined third and sixth nerve palsy are described. Both the patients had synergistic adduction on elevation and were treated by a single muscle transposition. Results: Both patients were orthotropic in the primary position with no diplopia and a reduction in synergistic adduction. Conclusion: Muscle transfer in the direction of aberrant movement works reasonably well in cases of partially recovered combined palsies. We present two cases detailing the usefulness of single muscle transposition, confirming the utility of this surgical technique in cases of aberrant regeneration.

Purpose: To study and evaluate the change in retinal nerve fiber layer (RNFL) and macular thickness and its clinical correlation with visual outcome following amblyopia therapy. Methods: In this prospective interventional study, children with moderate to severe amblyopia were given optical correction and part-time occlusion therapy. Visual assessment and optical coherence tomography (OCT) were performed at days 0 and 3, 6 months of follow-up. Results: A total of 30 children aged from 5 to 12 years with a mean age of 5.26 ± 1.65 years with moderate to severe amblyopia were included. About 19 patients (63.33%) were males and 11 patients (36.66%) were females. Anisometropia was the most common cause of amblyopia in our study population affecting 46.67% of patients. The mean global RNFL thickness in amblyopic eyes before and after patch therapy were 111.13 um and 104.96 um respectively (6.17 um thinner than better eyes). The macular thickness before and after patch therapy was 227.06 um and 226.80 um respectively (0.26 um thinner than better eyes). Conclusions: Part-time occlusion therapy results in visual gain in children with moderate to severe amblyopia. However, it causes thinning in both the RNFL and macular thickness at days 0 and 3, 6 months of follow-up.

Introduction: Amblyopia is a common disease, and interventions like patching treatment are well studied. When standard therapy fails, sometimes uncommon treatment options become necessary. Methods: We present three cases of patients with severe strabismic amblyopia with initial visual acuities of 20/400, 20/2000 and 20/160 who failed conventional treatment and subsequently received treatment with high-powered contact lenses (HPCL) of either + 22D or + 25D strength. Results: Visual acuity markedly improved in all three cases: 20/20, 20/50 and 20/25, respectively. Conclusion: While amblyopia treatment with HPCL will never be first-line therapy, our results are encouraging and show that this form of penalization should be considered if conventional therapy fails.

Introduction: There remains a lack of compelling objective evidence on whether stereopsis is necessary for an ophthalmic surgical career. It is also unclear if high-grade stereoacuity correlates with better surgical performance. The present study attempts to address this question by comparing the simulated surgical performance of subjects with different levels of stereoacuity using a virtual reality (VR) intraocular surgical simulator (EYESi, VRmagic, Mannheim, Germany). Methods: Subjects were tested based on their stereoacuity level and stratified in three age-matched groups: normal stereopsis, subnormal stereopsis, and patients with no measurable stereoacuity in the clinical setting. Eleven subjects in each group to make a total of 33 subjects with no prior surgical experience were recruited from the IWK Health Centre, Halifax, Canada (REB trial registration: 1023183). Subjects performed three attempts on a standardized microsurgical module on the EYESi VR simulator. Results: There was no significant main effect of the stereo-group that the participants belonged to on their total scores, or on the time needed to complete the task, or on the odometer value, or on the amount of injury to surrounding tissues. Discussion: This study showed that for a basic simulated microsurgical task on the EYESI intraocular surgical simulator, the performance of individuals with reduced and absent stereoacuity was statistically indistinguishable from those with normal stereoacuity. Therefore, caution is still recommended when advocating for mandatory high level of stereoacuity as a requirement for admission to training programs in ophthalmology. There is still definite need for solid evidence that stereopsis is necessary to achieve satisfactory skills in ophthalmic microsurgery.

Background: Inferior oblique muscle overaction (IOOA) is a prevalent ocular muscle motility disorder. This study aimed to investigate the outcomes and impact of IO muscle myectomy with and without tucking the proximal end of the muscle into Tenon's capsule in two surgical groups as a treatment for IOOA. Methods: Randomized cohort study that involves two surgical groups. A total of 33 patients (55 eyes). Patients were randomly divided into two groups: first group underwent myectomy without tucking the proximal end of the muscle, whereas the second group underwent myectomy with tucking of the proximal end of the muscle. Each patient had four visits. During each visit, each patient had a comprehensive ophthalmic examination. Surgical success was defined as IOOA grade range of 0 to + 1 and correction of hypertropia in primary gaze. Results: The median age was 6 years. Sixteen (48.5%) patients underwent IO muscle myectomy with tucking, while 17 (51.5%) had an IO myectomy without tucking. Both the tucking and without tucking groups showed reductions in the angles of deviations, but there was no significant difference between the groups at baseline or postoperatively at 6 months. The success rate was 92.85% for the tucking group and 92.59% for the without tucking group. Conclusion: The study suggests that both surgical techniques are effective in correcting IOOA and associated HT, without any clear benefits of the addition of tucking. Ultimately, the two surgical techniques are equally effective, and the choice of surgical technique remains a personal preference of the surgeon.

Purpose: Given the current scenario of increased smartphone use in youth, this study aims to evaluate the proportion of ocular symptoms and binocular dysfunction and their association with smartphone use in adolescents through a hospital-based cross-sectional study.

Methods: The participants were asked to fill out questionnaires related to smartphone use and symptoms of eyestrain experienced (Balik et al. and Kucer). They were asked about the following seven symptoms: blurring of vision, redness, visual disturbance, secretion, inflammation, lacrimation, and dryness. Each symptom out of the 7, was scored on a scale of 0-1 and was used to calculate an Ocular Symptom Score (OSS) by summing the scores of each symptom.Depending upon the duration of smartphone usage, the participants were classified into four groups: <2 hours/day, 2-4 hours/day, 4-6 hours/day, and >6 hours/day. Binocular functions were assessed using near point of convergence (NPC), near point of accommodation (NPA), Accommodative convergence/Accommodation (AC/A) ratio, dissociated heterophoria, and binocular accommodative facility (BAF).

Results: A total of 123 smartphone user adolescents, aged 10-19 years were included in this study. The mean age of the study population was 16.58 + 2.8 years, out of which 52.03% were males. Prevalence of ocular symptoms was higher in groups with greater duration of smartphone use (2 to 4, 4 to 6, and >6 hours/day as compared to <2 hours/day: 90.48%, 94.74%, 100% vs. 75% respectively). The mean of NPC was 8.51, it was highest in subjects using smartphones for >6 hours. (p-value = .001). The mean AC/A ratio was 2.83 + 1.03: 1. A low AC/A ratio was associated with a longer duration of smartphone usage (p-value = .0001). The mean of BAF was 7.4 + 3.18 cycles/min, only 30 (24.4%) participants had BAF beyond the normal range (<5 cycles/min). The mean of BAF was lowest in the group with >6 hours/day of smartphone use (p-value < .0001). No significant change was found in NPA and dissociated heterophoria with the duration of smartphone usage.

Conclusion: Higher duration of smartphone use (>2 hours/day) is associated with various ocular symptoms and binocular dysfunction. However, additional research is necessary to authenticate the results of the study.

Purpose: To describe the pathophysiology, importance of multimodal imaging approach, and the clinical outcomes of incomplete lacerating rectus muscle injuries. Methods: A retrospective review was conducted to identify patients with ocular deviation secondary to rectus muscle injuries. Between 2019 and 2022, a total of 30 patients were identified, amongst whom eleven patients had incompletely lacerated rectus muscles (secondary to penetrating adnexal trauma and sino-orbital surgeries). Patients' demography, nature of injury, computed tomography/magnetic resonance imaging, anterior segment optical coherence tomography features, intra-operative findings, and post-operative outcomes were reviewed. Results: The mean age of 11 patients was 31.36 ± 14.38 years. All patients had external trauma which severed the muscle in its anterior portion. Five patients had isolated inferior rectus muscle injury (45.45%), three had inferior and medial rectus muscle injuries together (27.27%), two had isolated lateral rectus muscle injury (18.18%), and one remaining patient had isolated medial rectus muscle injury (9.05%). In ten patients (90.90%) CT/MRI revealed features suggestive of muscle injury, however details with respect to muscle insertion and scleral course were lacking. In this difficult scenario, ASOCT filled these lacunae in nearly 90% of the patients by providing surgically useful details. Moreover, when CT/MRI-ASOCT imaging features were combined, the management and outcomes were even more predictable. Conclusions: Penetrating rectus muscle injuries can be better identified as incompletely lacerated muscle using multimodal imaging approach. This simple image correlation process customizes the treatment approach and hence the clinical outcomes.

Introduction: For decades, the saccadic system has been a favorite target of neurophysiologists seeking to elucidate the neural control of eye movements, partly because saccades are characterized by a set of highly stereotyped relationships between amplitude, duration, and peak velocity. There is a large literature describing the dynamics and trajectories of these movements in normal primates, but there are no similarly detailed analyses for subjects with infantile strabismus syndrome. Previous studies have shown the amplitudes and directions of saccades often differ for the two eyes in this disorder, but it is unknown whether a similar disconjugacy exists for duration. The present study was designed to determine whether or not saccade duration differs for the two eyes in strabismus, and whether there are abnormalities involving the trajectories of these movements. Methods: Dynamic analyses of saccade trajectories and durations were performed for two normal monkeys, two with esotropia and two with exotropia. The amount of curvature was compared for the two eyes. For each monkey with strabismus, the amount of curvature was compared to normal controls. Saccades were placed into 12 bins, based on direction; for each bin, the mean saccade duration was compared for the two eyes (duration disconjugacy). The duration disconjugacy for each bin was then compared for monkeys with strabismus, versus normal control animals. Results: Surprisingly, the amount of curvature was not consistently greater in subjects with pattern strabismus. However, saccade curvature differed for the two eyes by a significantly greater amount for all monkeys with strabismus, compared to normal controls. In addition, for a subset of saccades in subjects with strabismus, saccade duration differed for the two eyes by more than 10 ms, even when the animal was fully alert. Discussion: To the best of the author's knowledge, this is the first study to show that, in strabismus, saccade durations can differ for the two eyes by an abnormally large amount. These data also suggest that, in monkeys with pattern strabismus, abnormal horizontal-vertical crosstalk in brainstem can lead to directional disconjugacy without significantly impairing component stretching. These results place important constraints on future attempts to model the neural mechanisms that contribute to directional disconjugacy in pattern strabismus.

An abnormal head position (AHP) refers to a condition where the head is deviated from the usual, upright posture considered normal. AHPs can manifest as the chin being raised or lowered, the head tilted to the right or left, the face turned to either side, or a combination of these movements. Patients with AHP may present to ophthalmologic clinics; however, there are several etiologies for AHP that may not be commonly recognized by ophthalmologists. Key words from this article were searched in PubMed, Scopus, and Google Scholar search engines from 1975 to December 2023. Various etiologies were identified, evaluated, summarized, and then categorized. The maintenance of a normal head posture during our daily activities relies on the complex interaction of different parts of the brain, with the encoding of related sensory inputs occurring in the vestibular nuclei. Abnormal head posture can stem from a variety of etiologies, including ocular, neurological, orthopedic, otolaryngological, gastroenterological, and other factors. This review provides a comprehensive overview of the different characteristics of AHP based on its etiology. Lack of awareness regarding the wide spectrum of causes may lead to patients undergoing unnecessary extensive workups. Conversely, failure to recognize potentially life-threatening causes may result in adverse outcomes for the patient.