Adult Strabismus Preferred Practice Pattern®

Evaluation of Publications from the American Academy of Ophthalmology: A 5-Year Analysis of Ophthalmology Literature

Objective

To analyze recent publications in Ophthalmology, the journal of the American Academy of Ophthalmology.

Design

Retrospective review of published articles.

Participants

No human participants were involved in the study.

Methods

Articles published in Ophthalmology from January 2018 to December 2022 were reviewed and analyzed.

Main Outcome Measures

Research and review articles were included and analyzed per the following: total number of published articles based on related subspecialty area, level of evidence using the modified Oxford level of evidence, number of citations, number of listed authors, gender of the corresponding author, country of affiliation of the corresponding and contributing author(s), and involvement of consortium(s), group(s), or committee(s).

Results

A total of 965 articles were included. The mean (standard deviation) number of authors per article was 8.6 (5.7) and the majority of corresponding authors were male (665, 70.7%). The greatest number of published articles were related to retina (296, 30.7%) followed by glaucoma (172, 17.8%). The greatest number of Preferred Practice Pattern guidelines were also related to retina (7/24, 29.1%), followed by cornea/dry eye syndrome/external disease (6/24, 25%). Retina (77) had the most level 1 evidence, glaucoma (30) for level 2 evidence, and retina for levels 3 (69) and 4 (65). There were 223 articles contributed by consortia/groups/committees, with most from retina (73, 32.7%) followed by glaucoma (40, 17.9%). The mean number of citations per subspecialty article was highest in retina (45.8/article), followed by uveitis (31.7/article). The United States had the greatest number of affiliated corresponding authors (544, 56.4%), followed by the United Kingdom (68, 7.0%). There were 357 (37.0%) articles with coauthors affiliated outside the corresponding author's country of affiliation, although with a downward trend over the most recent 5-year period. There has been an increasing trend in the number of authors and consortia/group/committee involvement in publications.

Conclusions

Although team science and collaborations have increased recently, ongoing efforts to diversify individuals, groups, and subspecialties may be needed.

Financial Disclosures

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Deficits of Visual Cortex Function in Acute Acquired Concomitant Esotropia Patients

Purpose

The purpose of this study was to explore the cortical deficits of patients with acquired concomitant esotropia (AACE) using the resting-state functional magnetic resonance imaging (rs-fMRI) technique.

Methods

Rs-fMRI signals from 25 patients with AACE and 25 matched controls were collected. The repeated-measures analysis of variance (RM-ANOVA) test and two-sample t-test were used to investigate statistical differences of the amplitudes of low-frequency fluctuation (ALFF) signals and correlation analysis was performed to validate the relationship of signal change and clinical features.

Results

The AACE group showed decreased ALFF in both hemispheres symmetrically (t = 0.38, P = 0.71), with peak t in both middle occipital gyrus. The ALFF signal from the upper left inferior frontal gyrus was negatively correlated with the age of onset (r = 0.62, P = 0.0008), and the ALFF signal from the right superior temporal gyrus was negatively correlated with the near work hours (r = 0.63, P = 0.0008). The ALFF signal in the left fusiform gyrus was positively correlated with both near (r = 0.48, P = 0.01) and far (r = 0.44, P = 0.03) deviation, whereas it was only positively correlated with far deviation (r = 0.44, P = 0.03) in the right. Besides, the age of onset and the near work hour were independent factors of signal changes.

Conclusions

Using the ALFF signal of rs-fMRI, we found functional deficits in the primary visual cortex and dorsal pathway in patients with AACE. There were functional changes in the fusiform gyrus, and the greater the deviation angle, the higher the changing level. These findings reveal the association of AACE and the visual center, giving us more clues about the treatment of AACE.

Cortical Reorganization After Optical Alignment in Strabismic Patients Outside of Critical Period

PURPOSE

To measure visual crowding, an essential bottleneck on object recognition and reliable psychophysical index of cortex organization, in older children and adults with horizontal concomitant strabismus before and after strabismus surgery.

METHODS

Using real-time eye tracking to ensure gaze-contingent display, we examined the peripheral visual crowding effects in older children and adults with horizontal concomitant strabismus but without amblyopia before and after strabismus surgery. Patients were asked to discriminate the orientation of the central tumbling E target letter with flankers arranged along the radial or tangential axis in the nasal or temporal hemifield at different eccentricities (5° or 10°). The critical spacing value, which is the minimum space between the target and the flankers required for correct discrimination, was obtained for comparisons before and after strabismus surgery.

RESULTS

Twelve individuals with exotropia (6 males, 21.75 ± 7.29 years, mean ± SD) and 15 individuals with esotropia (6 males, 24.13 ± 5.96 years) participated in this study. We found that strabismic individuals showed significantly larger critical spacing with nasotemporal asymmetry along the radial axis that related to the strabismus pattern, with exotropes exhibiting stronger temporal field crowding and esotropes exhibiting stronger nasal field crowding before surgical alignment. After surgery, the critical spacing was reduced and rebalanced between the nasal and temporal hemifields. Furthermore, the postoperative recovery of stereopsis was associated with the extent of nasotemporal balance of critical spacing.

CONCLUSIONS

We find that optical realignment (i.e., strabismus surgery) can normalize the enlarged visual crowding effects, a reliable psychophysical index of cortical organization, in the peripheral visual field of older children and adults with strabismus and rebalance the nasotemporal asymmetry of crowding, promoting the recovery of postoperative stereopsis. Our results indicated a potential of experience-dependent cortical organization after axial alignment even for individuals who are out of the critical period of visual development, illuminating the capacity and limitations of optics on sensory plasticity and emphasizing the importance of ocular correction for clinical practice.

Comitant strabismus etiology: extraocular muscle integrity and central nervous system involvement-a narrative review

Strabismus is not a condition in itself but the consequence of an underlying problem. Eye misalignment can be caused by disease, injury, and/or abnormalities in any of the structures and processes involved in visual perception and oculomotor control, from the extraocular muscles and their innervations to the oculomotor and visual processing areas in the brain. A small percentage of all strabismus cases are the consequence of well-described genetic syndromes, acquired insult, or disease affecting the extraocular muscles (EOMs) or their innervations. We will refer to them as strabismus of peripheral origin since their etiology lies in the peripheral nervous system. However, in most strabismus cases, that is comitant, non-restrictive, non-paralytic strabismus, the EOMs and their innervations function properly. These cases are not related to specific syndromes and their precise causes remain poorly understood. They are generally believed to be caused by deficits in the central neural pathways involved in visual perception and oculomotor control. Therefore, we will refer to them as central strabismus. The goal of this narrative review is to discuss the possible causes behind this particular type of eye misalignment and to raise awareness among eyecare professionals about the important role the central nervous system plays in strabismus etiology, and the subsequent implications regarding its treatment. A non-systematic search was conducted using PubMed, Medline, Cochrane, and Google Scholar databases with the keywords "origins," "causes," and "etiology" combined with "strabismus." A snowball approach was also used to find relevant references. In the following article, we will first describe EOM integrity in central strabismus; next, we will address numerous reasons that support the idea of central nervous system (CNS) involvement in the origin of the deviation, followed by listing several possible central causes of the ocular misalignment. Finally, we will discuss the implications CNS etiology has on strabismus treatment.

Visual Crowding Reveals Field- and Axis-Specific Cortical Miswiring After Long-Term Axial Misalignment in Strabismic Patients Without Amblyopia

Purpose

Inspired by physiological and neuroimaging findings that revealed squint-induced modification of cortical volume and visual receptive field in early visual areas, we hypothesized that strabismic eyes without amblyopia manifest an increase in critical spacing of visual crowding, an essential bottleneck on object recognition and reliable psychophysical index of cortical organization.

Methods

We used real-time eye tracking to ensure gaze-contingent display and examined visual crowding in patients with horizontal concomitant strabismus (both esotropia and exotropia) but without amblyopia and age-matched normal controls.

Results

Nineteen patients with exotropia (12 men, mean ± SD = 22.89 ± 7.82 years), 21 patients with esotropia (10 men, mean ± SD = 23.48 ± 6.95 years), and 14 age-matched normal controls (7 men, mean ± SD = 23.07 ± 1.07 years) participated in this study. We found that patients with strabismus without amblyopia showed significantly larger critical spacing with nasotemporal asymmetry in only the radial axis that related to the strabismus pattern, with exotropia exhibiting stronger temporal hemifield crowding and esotropia exhibiting stronger nasal hemifield crowding, in both the deviated and fixating eyes. Moreover, the magnitude of crowding change was related to the duration and degree of strabismic deviation.

Conclusions

Using visual crowding as a psychophysical index of cortical organization, our study demonstrated significantly greater peripheral visual crowding with nasotemporal asymmetry in only the radial axis in patients with strabismus without amblyopia, indicating the existence of hemifield- and axis-specific miswiring of cortical processing in object recognition induced by long-term adaptation to ocular misalignment.

Trends in Etiologies, Demographics, and Neuroimaging in New-Onset Adult Strabismus at an Ophthalmic Emergency Department

PURPOSE

To evaluate new-onset strabismus in adults presenting to an ophthalmic emergency department, and to identify which patients require neuroimaging.

METHODS

This was a retrospective review of electronic medical records of patients 18 years and older who presented to an ophthalmic emergency department between January 1, 2019 and December 31, 2020 with new-onset strabismus. Data regarding demographics, causes, neuroimaging, and resolution were recorded and analyzed.

RESULTS

Of the 557 patients in the current study, 54.8% were men and the mean age was 57.3 ± 16.7 years (range: 18 to 92 years). Most patients (72.4%) presented with diplopia. Esotropia was the most common ocular misalignment (43.6%) and was more common in women than men (51.6% vs 37.0%, respectively) (P = .001). The most common diagnoses were cranial nerve palsies (66.8%) for both sexes and all age groups, with the most common etiology being microvascular (48.1%) for patients 50 years and older and idiopathic (20.1%) for patients between 18 and 49 years old. The incidence of cranial nerve palsies was significantly higher in older patients (P < .001). Neuroimaging was performed in 58% of patients (n = 323), of whom 37.2% (n = 120) had abnormal findings. The most common abnormal neuroimaging finding was mass for all age groups and sexes (19.2%). Patients with cranial nerve palsy and microvascular etiology had a significantly lower proportion of abnormal neuroimaging findings (P < .001).

CONCLUSIONS

Most cases of new-onset strabismus in adults presenting to the emergency department were due to cranial nerve palsy, particularly in older patients. Despite high rates of neuroimaging, patients with cranial nerve palsy had mostly normal findings. The current study supports the belief that neuroimaging may be deferred in patients older than 50 years with micro-vascular risk factors. [J Pediatr Ophthalmol Strabismus. 2022;59(4):269-273.].

Ocular Complaints, Disease, and Emergencies in the General Medical Setting

Primary care physicians see nearly half of all clinical visits, and 2% to 3% of those are for eye complaints. Taking a good ocular history is essential to establishing the diagnosis. Patient complaints fall into several categories including visual change, redness, and pain. Primary care physicians can screen for patients at risk of vision loss from glaucoma, diabetes, and toxic medication and ensure that patients have appropriate eye evaluations. Examination techniques such as direct ophthalmoscopy, evaluation of the red reflex, eversion of the upper lid, checking pupillary response, and using fluorescein to stain the cornea are helpful in evaluating patients' ocular complaints.