Sensory Strabismus; A Literature Review.

Persistent unilateral or bilateral visual deprivation at any age, particularly in children, can compromise sensory fusion and result in a type of strabismus known as sensory or secondary strabismus. There are several pathologies that can induce visual impairment, such as severe anisometropia, congenital unilateral cataract, corneal opacity, retinal diseases, and optic nerve anomalies. Sensory strabismus may be horizontal or vertical or a combination of them; however, most reports indicate the development of horizontal deviation as sensory strabismus. Regardless of the direction of the sensory strabismus, early diagnosis and management of the underlying pathology are important before strabismus treatment. The primary treatment approach for patients with sensory strabismus is surgery to correct ocular misalignment and straighten the eyes. This can help to improve the patients' symptoms and diminish the negative psychosocial impacts. In this article, we review the underlying etiologies and background pathologies associated with sensory strabismus. In addition, we investigate the determinant factors of the direction of sensory strabismus and its management strategies.

Brown syndrome: a literature review.

The current data on various aspects of Brown syndrome are limited and sporadic. This review provides a coherent and comprehensive review of basic features, etiology, classification, differential diagnosis, and different management strategies of patients with Brown syndrome. In this topical review, PubMed, Scopus, and Google Scholar search engines were searched for papers, published between 1950 and January 2023 based on the keywords of this article. The related articles were collected, summarized, categorized, assessed, concluded, and presented. Brown syndrome is identified by restricted passive and active elevation of the eye in adduction. The condition is divided into congenital and acquired causes. The clinical features result from a restricted motion of the superior oblique tendon sheath through the trochlea while trying to look up in adduction. The newest explanation of the underlying pathophysiology has been explained as the presence of a fibrotic strand in the superior oblique muscle tendon with variable insertion sites which creates various elevation deficits seen in Brown syndrome. The most common clinical features include the presence of an abnormal head posture, V-pattern strabismus, and hypotropia in the primary position. Management of Brown syndrome includes watchful observation, surgical, and non-surgical procedures. Some cases might resolve spontaneously without any intervention; however, some acquired cases might require systemic and/or intra-trochlear steroid administration to treat the underlying causes. Surgical procedures such as superior oblique tenectomy and using a silicon tendon expander are indicated in the presence of hypotropia and significant abnormal head posture in the primary position.

Basic acquired nonaccommodative esotropia patients managed with surgery; a study of 2102 patients.

INTRODUCTION: Several studies investigated preoperative clinical features of patients with basic-acquired nonaccommodative esotropia (BANAET); however, their sample sizes were small, and they did not compare the clinical features among cases that needed different surgery times. The main purpose of this study is to compare the preoperative clinical features of patients with BANAET managed with one surgery with patients who underwent two or more strabismus surgery over 10 years. METHODS: This historical cohort study was performed on the hospital records of 13,252 Iranian strabismic patients who underwent surgery at Farabi eye hospital, Tehran, Iran, from 2012 to September 2022. Of those, 2102 cases with BANAET were selected as the sample size. Data collected included sex, age at the time of first surgery, corrected distance visual acuity (CDVA), refractive error, presence of amblyopia, angle of deviation, and times of surgery. RESULTS: The mean age was 18.9 ± 15.6 [1200 (57.1%) males and 902 (42.9%) females] and the median age was 14 years. In 1599 (76.1%) patients, esotropia was managed with one surgery; however, 342 (16.3%) cases were managed with two surgeries and 161 (7.6%) patients underwent three or more surgeries. The mean angle of horizontal deviation at distance and near in patients managed with two and ≥3 surgeries was significantly higher than in cases managed with one surgery (P < .001). Amblyopia was observed in 289 (18.1%) patients who were managed with one surgery, 69 (20.2%) patients with two surgeries and 43 (26.7%) patients with three or more surgeries (P < .001). Patients with BANAET managed successfully with only one surgery were younger, had better CDVA, lower astigmatism and less horizontal angle of deviation at distance and near than those who underwent two or more surgeries (all P < .001). DISCUSSION: The higher astigmatism, lower CDVA, greater angle of horizontal deviation, and higher frequency of amblyopia were found in the preoperative examinations of BANAET patients managed with two or more surgeries compared with cases managed with only one surgery.

Clinical features and refractive profile of Brown syndrome.

CLINICAL SIGNIFICANCE: Understanding the refractive profile, amblyopia prevalence, binocular status, and head position in patients with Brown syndrome help clinicians become more familiar with this syndrome. BACKGROUND: Brown syndrome is identified as an active and passive restricted elevation of the eye in adduction. There is little information on clinical features, including refractive status, amblyopia, abnormal head posture (AHP), and types of deviation in these patients. METHODS: This study retrospectively evaluated records of 100 Brown syndrome patients from 2015 to 2022 at Farabi Eye Hospital, Iran. RESULTS: The mean age was 6.99 ± 6.33 years, including 48 (48%) males. A congenital source was found in 74 (74%) and 96 (96%) patients had unilateral involvement. The mean CDVA for the affected and non-affected eyes were 0.05 ± 0.11 and 0.03 ± 0.06 logMAR, respectively (P = 0.31). In unilateral cases, hyperopia, myopia, and emmetropia were observed in 55 (57.29%), 2 (2.08%), and 39 (40.63%) affected eyes, respectively. The most common type of deviation was pure hypotropia, which was found in 53 (53%) cases, followed by 'combined exotropia and hypotropia' observed in 26 (26%) patients. The mean angle of hypotropia and horizontal deviation in the primary position at distance was 12.10 ± 8.50 and 8 ± 13.20 prism dioptre, respectively. A V-pattern was found in 76 (76%) patients. Amblyopia was observed in 13 (21.67%) of 60 cooperative patients, and AHP was noticed in 66 (66%) patients, in which "combined chin up and contralateral face turn" was the most common type. CONCLUSION: About 75% of cases were congenital, 50% had pure hypotropia, 75% showed V-pattern, 20% had amblyopia, and AHP was observed in 67% of patients. The remarkable prevalence of amblyopia alongside the high occurrence of AHP should alert clinicians to carefully assess patients with Brown syndrome for sensory fusion and amblyopia.

The Correlation between Hypertropia and Head Tilt in Congenital Unilateral Superior Oblique Muscle Palsy.

PURPOSE: To evaluate the correlation between the angle of deviation in different gazes and the amount of head tilt in patients with congenital unilateral superior oblique muscle palsy (SOP). METHODS: This case series study was performed on 20 consecutive SOP patients with head tilt. Based on the Bielschowsky three-step test, the angle of deviation was measured in different gazes. Furthermore, the hypertropia difference between the two lateral gazes (gaze difference) and the two head tilt sides (bilateral head tilt difference) was calculated. For measuring head tilt, close-up pictures from 40 cm with a habitual abnormal head position were captured and analyzed by the Corel Draw X7 software. RESULTS: The mean age of patients was 13 ± 9 years (range, 2.5-31 years). The mean angle of hypertropia in ipsilateral and contralateral head tilt was 24.5 Δ ± 7.1 Δ and 6.5 Δ ± 4.2 Δ, respectively (P < 0.001), and in ipsilateral and contralateral lateral gaze positions, it was 8.2 Δ ± 5.5 Δ and 22.5 Δ ± 6.1 Δ, respectively (P < 0.001). The mean of bilateral head tilt hypertropia difference was 18 Δ ± 5.3 Δ and gaze hypertropia difference was 14.3 Δ ± 6.16 Δ. There was a positive correlation between bilateral head tilt hypertropia difference and the amount of head tilt (R = 0.609, R 2 = 0.371, P = 0.004, the amount of head tilt = 0.39 × [Bilateral head tilt hypertropia difference] +1.77). The amount of head tilt also had a positive correlation with the gaze hypertropia difference (R = 0.492, R 2 = 0.242, P = 0.028, the amount of head tilt = 0.27 × [gaze hypertropia difference] +4.81). CONCLUSION: In SOP patients, the amount of head tilt had a positive correlation with bilateral head tilt hypertropia difference and also gaze hypertropia difference.

Facial Asymmetry in Unilateral Congenital Superior Oblique Muscle Palsy.

SIGNIFICANCE: This study was conducted to evaluate facial asymmetry in unilateral congenital superior oblique muscle palsy (SOP). The results showed that all facial asymmetry parameters had a higher frequency in SOP patients compared with orthotropic individuals. PURPOSE: This study aimed to evaluate the characteristics of facial asymmetry in unilateral congenital SOP and compare with orthotropic individuals. METHODS: This cross-sectional comparative case series was conducted in 58 patients with ocular torticollis caused by SOP (mean ± standard deviation age, 18 ± 12 years) and 58 orthotropic individuals (mean ± standard deviation age, 19 ± 13 years). The exact form of torticollis was determined by direct observation from yaw, roll, and pitch axes. Four photographs were taken from patients: (1) with torticollis to calculate the amount of head tilt; (2) with the head in the straight position to calculate the facial angle and relative facial size (RFS); and (3 and 4) with the head positioned downward (to compare the cheek size) and upward (to assess columella deviation and nostril asymmetry). RESULTS: Twenty-nine patients (50%) had a head tilt, 23 (39.66%) had combined head tilt and a face turn, and 6 (10.44%) had a pure face turn. The mean ± standard deviation of head tilt, facial angle, and RFS was 10.11 ± 6.31°, 1.11 ± 1.67°, and 1.003 ± 0.126 in SOP patients, respectively, and the mean RFS and facial angle were significantly higher in SOP patients compared with orthotropic individuals (both P < .001). Facial hemihypoplasia, unilateral cheek compression, nostril asymmetry, and columella deviation were observed in 43 (74.1%), 31 (53.4%), 39 (67.2%), and 38 patients (65.5%), respectively, which were all significantly more common compared orthotropic individuals (P < .001). Facial asymmetry was seen in 52 patients (91.2%) and 17 orthotropic subjects (29.3%), respectively (P < .001). CONCLUSIONS: All quantitative and qualitative facial asymmetry parameters had a higher frequency in SOP patients compared with orthotropic subjects.

Abnormal Head Posture in Unilateral Superior Oblique Palsy.

Purpose: To evaluate the manifestations and severity of abnormal head posture (AHP) in unilateral congenital and acquired superior oblique palsy (SOP) patients and to assess the effect of AHP on facial appearance. Patients and methods: This case series study was performed on 60 consecutive SOP patients, which consisted of 47 patients with congenital SOP and 13 patients with the acquired source. The exact type of AHP in congenital and acquired cases was determined based on direct observation. In addition, a close-up picture from 40 cm with habitual AHP was captured from all patients. For evaluation of the severity of AHP and measurement of head tilt, these pictures were analyzed by the Corel Draw X7 software (Corel Corp, Canada). Besides, qualitative and quantitative facial asymmetry parameters were evaluated by the assessment of pictures of patients, which were taken in different gazes. Results: Five different manifestations of AHP were observed to the contralateral side of the palsy; 1 - pure head tilt, 2 - simultaneous head tilt and turn, 3 - pure head turn, 4 - head tilt and chin down, and 5 - head tilt and turn with chin down. The frequency of these five manifestations of AHP in the congenital group were 23 (48.9%), 10 (21.3%), 4 (8.5%), 5 (10.6%), and 5 (10.6%) patients, respectively (P <.001) and in acquired patients, were 1 (7.7%), 8 (61.5%), 2 (15.4%), 2 (15.4%), and 0 (0%), respectively (P =.024). In all SOP patients, the most common manifestations of AHP were pure head tilt (40%), simultaneous head tilt and turn (30%), and head tilt with chin down (11.7%), respectively. The mean degrees of head tilt in congenital and acquired patients were 15.10° ± 9.34° and 9.61° ± 5.84°, respectively (P =.022). Conclusion: The most common type of AHP in congenital SOP patients was contralateral head tilt, but in acquired cases was simultaneous head tilt and turn. The mean amount of head tilt in the acquired group was significantly higher than congenital patients; in contrast, the frequency of facial asymmetry was higher in the congenital group compared with the acquired patients.

Ocular Abnormal Head Posture: A Literature Review.

PURPOSE: To provide a comprehensive review on different characteristics of abnormal head postures (AHPs) due to different ocular causes, its measurement, and its effect on facial appearance. METHODS: In this review article, PubMed, Scopus, and Google Scholar search engines were searched for the scientific articles and books published between 1975 and September 2020 based on the keywords of this article. The selected articles were collected, summarized, classified, evaluated, and finally concluded. RESULTS: AHP can be caused by various ocular or nonocular diseases. The prevalence of ocular causes of AHP was reported to be 18%-25%. 1.1% of patients presenting to ophthalmology clinics has AHP. The first step in evaluating a patient with AHP is a correct differential diagnosis between nonocular and ocular sources by performing comprehensive eye examinations and ruling out other causes of orthopedic and neurological AHP. Ocular AHP occurs for a variety of reasons, the most important of which include nystagmus, superior oblique palsy, and Duane's retraction syndrome. AHP may be an essential clinical sign for an underlying disease, which can only be appropriately treated by the accurate determination of the cause. Long-standing AHP may lead to facial asymmetry and secondary muscular and skeletal changes. CONCLUSION: In conclusion, a proper differential diagnosis between nonocular and ocular causes, knowledge of the different forms of AHP and their measurement methods, accurate diagnosis of the cause, and proper and timely treatment of ocular AHP can prevent facial asymmetry and secondary muscular and skeletal changes in the patients.

Facial Asymmetry in Unilateral Duane Retraction Syndrome.

SIGNIFICANCE: The overall objective of this study was to evaluate facial asymmetry in patients with unilateral Duane retraction syndrome (DRS). The results showed a high frequency of facial asymmetry parameters of the opposite side of head turn in unilateral DRS patients. PURPOSE: The purposes of this study were to evaluate the characteristics of facial asymmetry in unilateral exotropic and esotropic DRS and to compare the findings with orthotropic subjects. METHODS: This cross-sectional comparative case series study was performed in 44 consecutive patients with head turn caused by DRS and 44 orthotropic subjects from 2016 to 2019. Four pictures were taken from the patients' faces. The first and second pictures were taken when patients had head turn and when the head was completely straight for calculating the facial angle and relative facial size, respectively. The third and fourth pictures were taken when the head was positioned downward (to compare the size of the cheek) and upward (to evaluate nose asymmetry). RESULTS: The mean ± SD age of DRS patients and orthotropic subjects was 16.23 ± 9.92 and 20.68 ± 11.82 years, respectively. The frequency of facial asymmetry and all facial parameters (cheek compression, nasal tip and columella deviation, and compression of one of the nostrils) was significantly higher in DRS patients compared with orthotropic subjects (P < .001). In DRS patients with facial asymmetry, columella and nasal tip deviation (P = .006) and cheek and face compression (P = .03) were significantly more prevalent in the opposite direction of head turn. In the DRS group, the mean ± SD age of the patients with and without facial asymmetry was 17.37 ± 9.76 and 7.40 ± 6.54 years, respectively (P = .02). CONCLUSIONS: The frequency of facial asymmetry and all facial parameters was significantly higher in DRS patients compared with orthotropic subjects. In unilateral DRS patients, the face was more commonly affected on the opposite side of head turn.

The effect of different amblyopia treatment protocols on axial length of non-amblyopic eyes in anisohyperopic patients.

PURPOSE: To evaluate the effect of full-time and part-time occlusion therapy on axial length (AL) of non-amblyopic eyes in anisohyperopic patients. METHODS: Sixty-five patients who were treated for anisohyperopic amblyopia were recruited for this prospective cross-sectional study. Treatment was provided as patching of the non-amblyopic for 4 h or less (part-time occlusion therapy, n = 42), patching of the non-amblyopic for 8 h or more (full-time occlusion therapy, n = 13) and refractive correction (spectacles, non-patched group, n = 10). AL measurements were calculated by a Lenstar LS 900 at the last session of amblyopia therapy. RESULTS: The mean age of patients treated for anisohyperopic amblyopia was 4.90 ± 0.80 years, and the mean follow-up period was 1.50 ± 0.80 years. The mean of spherical equivalent in amblyopic and non-amblyopic eyes were +3.58 ± 2.26 and +1.84 ± 0.97 diopter (D) before treatment, and +3.21 ± 2.28 and +1.49 ± 0.99 D after treatment, respectively. The mean of spherical equivalent in non-amblyopic eyes before (F = 0.452, df = 2, P = 0.639) and after (F = 0.190, df = 2, P = 0.828) treatment did not have any significant difference between the three groups. The mean AL of amblyopic and non-amblyopic eyes were 22.11 ± 93.0 and 22.68 ± 1.07 mm, respectively. The mean AL of the non-amblyopic eye was significantly higher in the full-time occlusion therapy group when compared to the part-time patch and the non-patched groups (P < 0.001). The mean AL of amblyopic eyes showed no difference across the three treatment groups (P = 0.840). CONCLUSIONS: The results show that a longer AL in the non-amblyopic eye, but not the amblyopic eye, can be expected with longer daily hours of patching in anisohyperopic patients. Future studies are needed to evaluate the effect of patching on AL in children with anisohyperopic amblyopia.

The prevalence of strabismus types in strabismic Iranian patients.

PURPOSE: To determine the frequency of different types of strabismus and amblyopia in the patients of strabismus clinics from 2008 to 2014. METHODS: This retrospective cross-sectional study was conducted using data from the archives of Farabi Hospital in Tehran, Iran, from 2008 to 2014. The study consisted of using records of strabismic patients. From these, strabismus types and associated abnormalities, types of amblyopia and other ocular pathological findings were recorded. RESULTS: In this study, 1174 strabismic patients were studied. Accommodative esotropia (ET) was the most prevalent type of strabismus accounting for 25.04% of all strabismic patients while intermittent exotropia (XT), nonaccommodative ET and partially accommodative ET, with 12.09%, 11.24% and 10.39%, respectively, were relatively common. Also, 63.03% of all strabismic patients had esodeviation with XT coming second accounting for 24.53% of patients. Other ocular pathologic findings in addition to strabismus were found in 236 (20.1%) patients. The most common association with those types of strabismus was inferior oblique over action accounting for 11.07% of all cases, and 88 patients had nystagmus in addition to strabismus. Significantly 45% of patients had no amblyopia and 37% of patients had a combined type of amblyopia which was the most common type of amblyopia found in strabismic patients. CONCLUSION: The prevalence of ET was two and a half times more than XT and almost half of strabismic patients suffer from amblyopia. This study suggests that strabismus screening of children could be useful in the early detection of strabismus, appropriate management of it and prevention of strabismic amblyopia.