Intermittent Exotropia Research Articles

The Comparison of Long-term Surgical Results for Sensory Exotropia and Comitant Exotropia

Purpose: To compare the long-term surgical outcomes of patients with sensory and concomitant exotropia and to define the factors associated with successful surgical outcomes in those with sensory exotropia.Methods: The medical records of patients with sensory exotropia who underwent operations and were followed-up for at least 2 years were retrospectively reviewed. We enrolled patients exhibiting only best-corrected visual acuities ≤ 20/100 of the operated eyes. Surgical success was defined as a final distance deviation < 10 prism diopters (PD) with the eye in the primary position. Twenty-eight patients operated upon to treat sensory exotropia and 28 who underwent operations to treat concomitant exotropia who did not differ in terms of the gaze deviation angle were matched in terms of age, sex, and the preoperative distance and near distributions; their surgical outcomes were compared. Factors affecting such outcomes were identified using a multivariate Cox’s proportional hazards model.Results: The mean follow-up times were 91.7 ± 45.8 months in the sensory and 42.6 ± 27.7 months in the concomitant exotropia groups. The cumulative probabilities of surgical success 2 years after surgery were 74.5% in the sensory and 74.4% in the intermittent exotropia groups, thus not significantly different (<i>p</i> = 0.988). The Cox’s proportional hazard model showed that a greater difference between the preoperative distant and near deviations was associated with recurrence (<i>p</i> = 0.091).Conclusions: The long-term surgical outcomes of patients with sensory and concomitant exotropia were comparable. A high-level near-distance disparity increased the risk of recurrence.

Clinical Outcomes and Nutritional Status of Children with Intermittent Exotropia Treated with Surgery During the Preschool and Post-School Age

In this study, we compared the clinical outcomes and differences in nutritional status between preschool and post-surgical treatment of intermittent exotropia. We selected 100 children with intermittent exotropia between August 2019 and August 2022 for the study. Among them, 42 children received surgical treatment before school age (4–6 years) and were considered to be in group A, whereas 58 children received surgical treatment after school age (7–12 years) and were considered to be in group B. We found no difference in orthokeratology, overcorrection, or undercorrection rates between the two groups of children before and after surgery (P > 0.05), and the strabismus was lower at 6 and 12 months after surgery than before surgery and lowest at 12 months after surgery (P < 0.05). In addition, the normal rates of visual function, fusion function, and binocular stereopsis were higher in group A than in the control group at 6 and 12 months postoperatively (P < 0.05). The Child Intermittent Exotropia Questionnaire scores were higher in both groups at 12 months postoperatively than at 6 months and were higher in group A than in group B (P < 0.05). Family members of children in group A were more satisfied with the treatment than in group B (P < 0.05), but the difference in albumin, transferrin, and proalbumin before and after surgery was lower in group B than in group A (P < 0.05). It follows that performing intermittent exotropia surgery before school age can more effectively improve the prognosis of children’s binocular visual function, whereas performing intermittent exotropia after school age has less impact on nutritional status.

Outcomes of inferior oblique myectomy versus recession combined with lateral rectus recession in V-pattern exotropias

PurposeTo compare outcomes of bilateral lateral rectus recession (BLRc) paired with either bilateral inferior oblique myectomy (BIOm) or bilateral inferior oblique recession (BIOc) to correct V-pattern exotropia. MethodsThe medical records of children (≤18 years) who underwent BLRc with BIOm or BIOc (10 mm) for V-pattern intermittent exotropia between December 2020 and May 2022 and who had at least 6 months’ postoperative follow-up were reviewed. Outcomes included horizontal alignment, bilateral inferior oblique action, stereopsis, postoperative exotropia control score, and additional strabismus surgeries. Analysis was stratified by preoperative V pattern into subgroups of 10Δ-14Δ and ≥15Δ. ResultsFifty patients underwent BLRc with BIOm (n = 26) or BIOc (n = 24), with no difference in age, sex, or follow-up length. Preoperatively, there were no differences in stereopsis, horizontal or vertical deviations in primary position, strabismus control, or inferior oblique overaction (IOOA). The BIOc group had greater preoperative V pattern than the BIOm group (18.1 ± 6.8 D vs 14.3 ± 7.0 D, resp. [P = 0.03]). There was no difference in BLRc surgical dose. At final follow-up (mean, 448 ± 189 days), both groups showed a postoperative decrease in horizontal deviation, amount of V pattern, and IOOA. For patients with ≥15Δ V pattern, BIOm decreased V pattern amount at distance (P = 0.02) and IOOA (P = 0.0035) more than BIOc, and BIOm patients had better control of residual strabismus at distance (P = 0.03) compared with the BIOc group overall, as well as for both V pattern subgroups. Two patients with BIOm and one with BIOc underwent additional strabismus surgery. ConclusionsBIOm or BIOc in combination with BLRc decreased the angle of exotropia and improved control. However, BIOm, especially with large V patterns, had a greater effect on decreasing the V pattern and IOOA and showed better control of residual strabismus.

Preoperative visual function characteristics having an effect on the success of exotropia surgery

Background: There are individual reports on the effect of some preoperative characteristics of visual functions (like convergence, angle of deviation, presence of fusion and type of binocular vision) on the success of exotropia surgery. To date, however, it has not been established what are the major diagnosis-related prognostic factors for the success of surgery for exotropia. Purpose: To identify the preoperative characteristics of visual functions which have an effect on the success of surgery for exotropia. Material and Methods: Of the 59 exotropes (age range, 10 to 21 years) included in this study, 33 had basic constant exotropia (group 1) and 26, intermittent exotropia (group 2). Patients underwent an ophthalmological and ortoptic examination of the motor and sensory systems of the eye. Patients with surgery success (postoperative orthotropes) were compared to those who had a residual exotropia of more than 10 prism diopters (PD) postoperatively in terms of the preoperative accommodative convergence–accommodation (AC/A) ratio, near point of convergence (NPC), distance stereopsis and near stereoacuity threshold. Results: Our analysis of the preoperative NPC, AC/A ratio and stereopsis for the group with postoperative orthotropic alignment and the group with postoperative exotropic alignment found preoperative close to normal values of AC/A ratio (4.0 ± 1.65 PD/D), NPC (8.03 ± 3.02 cm), the presence of distance stereopsis and near stereopsis (passing the 200 second of arc image on the Lang II stereo card) and the absence of medial rectus hypofunction of hyperfunction in 83.05% of patients of the former group. Conclusion: Preoperative close to normal values of AC/A ratio (4.0 ± 1.65 PD/D), NPC (8.03 ± 3.02 cm), the presence of distance stereopsis and near stereopsis (passing the 200 second of arc image on the Lang II stereo card) and the absence of medial rectus hypofunction of hyperfunction can be the factors favoring the success of exotropia surgery.

Treatment of intermittent exotropia in children using a lateral rectus fenestration technique

To report the results of bilateral fenestration of the lateral rectus muscle in cases of intermittent exotropia in pediatric patients. Children <12 years of age with basic and pseudo-divergence excess type intermittent exotropia who underwent bilateral lateral rectus muscle fenestration were prospectively enrolled in this study. Success was defined as postoperative alignment within 8Δ of orthotropia in the primary position at the last follow-up. A total of 36 children were included. The mean preoperative angle of deviation at distance improved from 33.1Δ ± 3.8Δ (range, 25Δ-40Δ) preoperatively to 4.5Δ ± 5.7Δ (range, 0-16Δ) postoperatively (P < 0.001). The near angle was reduced from 32.0Δ ± 4.2Δ (range, 25Δ-35Δ) to 2.8Δ ± 4.5Δ (range, 0Δ-14 Δ) postoperatively (P < 0.001). Successful outcome was achieved in 81% of the cases at the 6-month follow-up. There were no reported intra- or postoperative complications. In our study cohort, bilateral fenestration of the lateral rectus muscle resulted in successful outcomes in the majority of patients, resulting in a significant reduction in angle of deviation in primary position at both distance and near fixation.

Surgical outcomes of bilateral lateral rectus recession versus unilateral recession and resection for the divergence excess type of intermittent exotropia.

To compare bilateral lateral rectus recession (BLR) with unilateral recession and resection (RR) for divergence excess intermittent exotropia (IXT). Retrospective analysis of 66 patients with divergence excess IXT who underwent either BLR or RR from January 2013 to December 2020 was conducted. Data on demographics, pre- and postoperative deviations, fusion, stereopsis, control, and accommodative convergence/accommodation ratio were collected. Success was defined as esodeviation ≤5 PD (prism diopter) to exodeviation ≤10 PD with a follow-up time of at least 8.0 ± 2.0 weeks. BLR (42 cases) and RR (24 cases) groups had the same success rate (83.3%, P = 0.688) and similar reduced postoperative deviations both in distance and at near (P > 0.05). Near-distance disparity decreased significantly in both groups (P = 0.000) with no intergroup difference (P = 0.193). BLR and RR were equally effective for divergence excess IXT with comparable outcomes of both distance and near deviations.

Effect of visual perception training on binocular visual function reconstruction in patients after strabismus surgery.

To explore the effect of visual perception learning software training (VPT) on binocular visual function reconstruction in children with intermittent exotropia after strabismus surgery. Ninety children with intermittent exotropia admitted to our hospital from June 2018 to December 2018 were included, and randomly divided into VPT and control groups. Children in the control group received basic binocular vision training, while those in the VPT group received VPT after strabismus surgery. Tertiary visual function, visual perception function, Newcastle Control Score (NCS), and ocular position retraction rate were compared at 3 and 12mo after the surgery. At 3 and 12mo after the surgery, the proportion of simultaneous perception, binocular fusion version and binocular stereo vision in the VPT group was conspicuously higher than that in the control group (P<0.05). After the vision training, the binocular visual perception functions of children in both groups were significantly improved compared with that before training (P<0.05). Interestingly, the grating sharpness, texture perception and texture motion perception in the VPT group were dramatically better than control group (P<0.01). The NCS in the VPT group was significantly lower than that in the control group (P<0.05). The ocular position retraction rate in the VPT group was significantly lower than that in the control group at 12mo (8.89% vs 26.67%, P=0.03). VPT effectively promotes binocular visual function reconstruction in intermittent exotropia children after strabismus surgery and reduces the strabismus severity and ocular position retraction rate.

Retracted: Contrast Agent and Molecular Imaging Meta-Analysis of the Clinical Effect of Intelligent Image Sensor Combined with Visual Training in the Treatment of Children with Intermittent Exotropia in China.

[This retracts the article DOI: 10.1155/2022/5387928.].

Characteristics of childhood intermittent exotropia with and without DVD

ABSTRACT Purpose: Although dissociated vertical deviation (DVD) is reported to occur rarely in children with intermittent exotropia (IXT), little is known regarding the clinical features of these children. The purpose of this study was to compare the demographic and clinical characteristics of children with intermittent exotropia and DVD to those without DVD. Methods: The medical records of all children diagnosed with intermittent exotropia at our institution from 1 January 2002, through 31 December 2018, who had 2 or more exams with 3 or more assessments of control, were retrospectively reviewed. Exotropic children with DVD were compared to those without DVD. Results: During the 17-year study period, 115 children met the inclusion criteria, of which 25 (21.7%) had DVD. Compared to the 90 exotropic children without DVD, children with IXT and DVD were more likely to have a motility disorder (p = .021), a worse mean distance control score (2.8 vs 2.4; p = .09), a larger mean angle of deviation (27.8 prism diopters [PD] vs 25.1 PD; p = .04), and a lower median stereopsis (200 secs vs 100 secs; p = .08). The children with DVD were more likely to have undergone surgery (p = .17) although there was no difference in the mean age at initial surgery between the two groups. Conclusions: The presence of dissociated vertical deviation in children with intermittent exotropia is associated with more motility disorders and worse binocular function compared to those without DVD. These children will likely require closer observation and earlier intervention.

Characterization and Classification of Postoperative Cysts After Strabismus Surgery: Clinical, Histological, and Anterior Segment OCT Analysis in a Large German Cohort.

In this work, we provide a detailed characterization of a rare complication-subconjunctival cyst formation after strabismus surgery-in a large German cohort. We conducted a retrospective analysis of 822 consecutive patients who underwent strabismus surgery between 2015 and 2022. The patients received comprehensive eye and orthoptic examinations preoperatively, at 1day, and at 3months postoperatively. Cysts were analyzed with slit-lamp examination, anterior segment optical coherence tomography (AS-OCT), and histopathological subsumption. Nineteen cases of postoperative cysts were observed (2.3%), 12 of which underwent surgical revision. Clinical evaluation including slit-lamp and AS-OCT as well as histological analysis resulted in a classification of three types of cysts: type 1, which is a single hyporeflective cyst, type 2, which is a multilobular hyporeflective cyst, and type 3, a dense hyperreflective granulomatous-like cyst. Eta (η) correlation ratio analysis could show a correlation between time of clinical appearance and type of cyst (Eta = 0.63). Most cysts developed within 20days after surgery. Not only did cysts more frequently affect the medial rectus muscle, which in most cases underwent a shortening procedure (11/19 tucks, 4/19 resections) for intermittent exotropia (X(T)), but the cyst also formed earlier than in the lateral rectus muscle (Eta = 0.45). No correlation could be shown between the type of surgical procedure and time of cyst occurrence (Eta = 0.1). Patient age and cyst type correlated strongly (Eta = 0.47). The underlying type of strabismus did not correlate with the type of cyst observed. Our cases showed a strong positive correlation to the type of strabismus (X(T)), age (young patients), and the procedure (tuck/resection). We introduce a grading system for postoperative cysts after strabismus surgery, complementing histopathology and slit-lamp aspects with AS-OCT information.

Refractive change in pediatric patients with intermittent exotropia

To determine the relationship between intermittent exotropia (IXT) and refractive change and the effects of the methods applied in IXT follow-up on refractive change. The medical records of 228 patients with IXT (group 1) and 110 patients without strabismus (group 2) who were followed between 2008 and 2022 were analyzed retrospectively. Group 1 was divided into three subgroups: overminus correction (group 1A), patients who underwent surgery (group 1B), and patients who were observed (group 1C). Annual myopic progression was -0.21 ± 0.32 D (range, -1.26 to +1.92) in group 1 and -0.07 ± 0.30 D (range, -1.13 to +1.00) in group 2 (P < 0.001). Annual myopic progression was -0.26 ± 0.29 D (range, -1.26 D to +0.12 D) in group 1A, -0.25 ± 0.35 D (range, -1.15 D to +0.25 D) in group 1B, and -0.19 ± 0.33 D (range, -1.12 D to +1.92 D) in group 1C. There was no difference in annual myopic progression between the subgroups (P = 0.670). The annual change in myopic refraction between each of the group 1 subgroups and group 2 was statistically significantly different (P < 0.001, P = 0.023, P< 0.001, resp.). Myopia progression was significantly greater in children with IXT than in the normal population. Myopia progression did not vary with exotropia treatment.

Changes in Angle of Exodeviation According to Distance after Monocular Occlusion in Intermittent Exotropia

Purpose: This study investigated changes in the angle of exodeviation at different distances and the characteristics of a group that showed an increased angle following monocular occlusion in intermittent exotropia.Methods: In all, 102 patients diagnosed with basic intermittent exotropia were enrolled. The deviation angle was measured using a mirror at 33 cm, 3 m, 6 m, 12 m, and 6 m. Moreover, the deviation was measured at 33 cm and 3 m after patching the non-dominant eye for 1 hour. Patients with a higher deviation angle at 33 cm after occlusion were categorized as the ‘increased group’, whereas those with lower deviation angles were classified as the ‘stationary group’.Results: There was a male-to-female ratio of 46:56 and an average age at surgery of 9.23 years. No significant differences were observed in deviation measurements taken at 3, 6, 12, and 6 m using a mirror. However, after occlusion, there was a significant increase in deviation at 33 cm (&lt;i&gt;p&lt;/i&gt; &lt; 0.01). The average log value of near stereoacuity was 1.96 ± 0.35 in the increased group and 2.16 ± 0.41 in the stationary group. The group with an increased near deviation after occlusion demonstrated a significantly improved near stereoacuity (&lt;i&gt;p&lt;/i&gt; = 0.01) and an increased proportion of good results in the near Worth 4 dot test (&lt;i&gt;p&lt;/i&gt; = 0.03).Conclusions: Preoperative measurement of maximum deviation after 1 hour of monocular occlusion can help reduce recurrence and insufficient correction, particularly in patients with good fusional ability.

Visual function in Norwegian children aged 5-13 years with prenatal exposure to opioid maintenance therapy: A case-control study.

To assess various aspects of visual function in school children prenatally exposed to opioid maintenance therapy (OMT) and to explore possible outcome differences between prenatal methadone and buprenorphine exposure. In a cross-sectional case-control study, 63 children aged 5-13 years with prenatal OMT exposure were compared with 63 age- and gender-matched, non-exposed controls regarding important visual parameters, such as visual acuity, orthoptic status, refractive state, colour vision, and visual field. The OMT-exposed children had significantly poorer visual acuity, both for the best eye, the worst eye and binocularly. Two children had mild visual impairment. Manifest strabismus was more frequent in the OMT group, 30%, vs. 4.8% in the control group. The most frequent types of strabismus were accommodative esotropia and intermittent exotropia. Manifest nystagmus was present in 10 (16%) of the exposed children compared to one among the non-exposed children. The accommodative amplitude was decreased in the OMT group compared to the controls. After adjusting for polydrug exposure and SGA (small-for-gestational-age), the between-group differences in visual acuity, strabismus, and nystagmus remained. The methadone-exposed children had poorer visual acuity, increased frequency of strabismus and a higher percentage of nystagmus, hypermetropia and astigmatism compared to the buprenorphine-exposed children. School-age children exposed to methadone or buprenorphine in utero had a higher prevalence of strabismus and nystagmus, and a lower visual acuity and accommodation amplitude. Buprenorphine exposure was associated with more favourable results than methadone exposure on most visual outcome measures and should be the preferred substance in OMT.

Eight-Year Outcomes of Bilateral Lateral Rectus Recessions versus Unilateral Recession-Resection in Childhood Basic-Type Intermittent Exotropia

To report 8-year outcomes from a randomized controlled trial (RCT) comparing bilateral lateral rectus muscle recession (BLRc) with unilateral recession-resection (R&R) for childhood intermittent exotropia (IXT). Eight-year follow-up of RCT cohort. Of 197 randomized participants, 123 agreed to continue follow-up after the 3-year outcome visit (baseline age, 3-< 11 years; basic-type IXT, 15-40 prism diopters [Δ] by prism and alternate cover test [PACT]; baseline stereoacuity, ≤ 400 arcsec; no prior surgery). After the RCT primary outcome at 3 years, annual follow-up from 4 through 8 years with treatment at investigator discretion. Suboptimal surgical outcome by 8 years after randomization, defined as any of the following at any visit: exotropia of 10 Δ or more by simultaneous prism cover test (SPCT) at distance or near, constant esotropia (ET) of 6 Δ or more by SPCT at distance or near, loss of near stereoacuity by 0.6 log arcsec or more from baseline, or reoperation. Secondary outcomes included (1) reoperation by 8 years and (2) complete or near-complete resolution at 8 years, defined as exodeviation of less than 10 Δ by SPCT and PACT at distance and near and 10 Δ or more reduction from baseline by PACT at distance and near, ET of less than 6 Δ at distance and near, no decrease in stereoacuity by 0.6 log arcsec or more from baseline, and no reoperation or nonsurgical treatment for IXT. The Kaplan-Meier cumulative probability of suboptimal surgical outcome through 8 years was 68% (55 events among 101 at risk) for BLRc and 53% (42 events among 96 at risk) for R&R (difference, 15%; 95% confidence interval [CI], -2% to 32%; P= 0.08). Complete or near-complete resolution at 8 years occurred in 15% (7/46) for BLRc and 37% (16/43) for R&R (difference, -22%; 95% CI, -44% to -0.1%; P= 0.049). The cumulative probability of reoperation was 30% for BLRc and 11% for R&R (difference, 19%; 95% CI, 2%-36%; P= 0.049). Despite no significant difference for the primary outcome, the 95% CI did not exclude a moderate benefit of R&R, which together with secondary outcomes suggests that unilateral R&R followed by usual care may yield better long-term outcomes than BLRc followed by usual care for basic-type childhood IXT using these surgical doses. Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Analysis of postoperative exodrift according to surgical methods for intermittent exotropia.

This study aimed to compare the periods for exodrift stabilization and the long-term surgical outcomes among different surgical methods in intermittent exotropia. The medical records of 350 patients who had undergone intermittent exotropia correcting surgery [unilateral lateral rectus recession-medial rectus resection (R&R, n = 221), bilateral lateral rectus recession (BLR, n = 51) and unilateral lateral rectus recession (ULR, n = 78)] with a postoperative follow-up period of 1.5 years or more were retrospectively reviewed. The deviation angles every 6 months after surgery, periods of exodrift stabilization and surgical outcomes were analysed. The period of postoperative exodrift stabilization was defined as when exodrift was no longer significantly different from that at the next visit (p > 0.05). An alignment of 5 PD (prism diopters) esotropia to 10 PD exotropia at a distance and near fixation was considered surgical success. The mean angle of exodeviation was significantly different among surgical procedures at postoperative 1 month (BLR > ULR > R&R, p < 0.001); however, there were no differences among the procedures at 6 months (p = 0.088). The periods of exodrift stabilization were 6 months after ULR, 1 year after BLR and 4.5 years after R&R. The surgical success and reoperation rates did not show significant differences among procedures at the final follow-up. Patients undergoing R&R showed smaller exodeviation shortly after surgery but required a longer period to stabilize the exodrift. Following ULR, exodeviation was larger in the early postoperative period, but the exodrift was stabilized earlier. Therefore, the long-term surgical outcomes were similar among ULR, BLR and R&R.

Refractive Profile of Surgical Patients with Intermittent Exotropia: A Large-Sample Cross-Sectional Study in Southern China

Purpose To describe the refractive profile of surgical patients with intermittent exotropia (IXT) residing in southern China. Methods Medical records of patients who received strabismus surgery between June 2014 and August 2020 were retrospectively reviewed. Clinical data, including age, sex, refractive errors, preoperative angle of deviation, types of exotropia, accommodative convergence to accommodation ratio (AC/A ratio) and stereopsis, were investigated. Results A total of 2250 patients were included, and 93.6% of patients were younger than 30 years of age. The mean angle of exodeviation was 37.0 ± 14.7 prism degree (PD) and 37.5 ± 15.8 PD at distance and near, respectively. Mean spherical equivalent refraction (SER) values were -0.7 ± 2.4 D and −0.8 ± 2.5 D in the dominant eye and nondominant eye, respectively. Significant differences in SER were observed between the dominant eye and nondominant eye among children at 6 years old or younger. The percentage of myopia increased from 11.0% in children (≤6 years old) to 77.9% in teenagers (13-18 years of age). Significant positive associations between the magnitude of exodeviation and the magnitude of myopia were observed (p < 0.0001). Patients with convergence insufficiency type IXT (p < 0.0001) or AC/A < 2 (p < 0.05) showed a greater magnitude of myopia. The mild hyperopia group included a larger proportion of subjects showing a certain degree of stereopsis (p < 0.05). Conclusions Myopia was present in more than half of our patients (51.2%), which is much higher than the percentage in the general population of southern China. Patients with convergence insufficiency, an AC/A ratio < 2, or a larger angle of deviation tended to have a greater magnitude of myopia.

Structural and spontaneous functional brain changes in visual and oculomotor areas identified by functional localization task in intermittent exotropia children

Intermittent exotropia (IXT) is characterizedby an intermittent outward deviation of the eyes. Yet, the neural substrates associated with IXT are not fully understood. This study investigated brain structure and spontaneous functional activity changes in children with IXT. All participants underwent detailed ophthalmological examinations and multimodal magnetic resonance imaging (MRI) scanning. During functional scanning, binocular visual stimuli were presented to subjects to determine brain areas involved in visual and oculomotor processing. Regions of interest(ROI) were subsequently selected based on functional activation to investigate brain structural and spontaneous functional differences between IXT children and healthy controls (HCs) using small volume correction (SVC). Reduced gray matter density (GMD) was found in the right frontal eye field (FEF) and bilateral inferior parietal lobe (IPL) in IXT children compared with HCs. Besides, reduced fractional amplitude of low-frequency fluctuations (fALFF) values were observed in the left lingual gyrus, right inferior occipital gyrus (IOG), bilateral IPL, and bilateral cerebellum in the IXT children compared to the HCs. IXT children with worse eye position control ability exhibited lower GMD and fALFF values in these areas. Finally, resting state functional connectivity (RSFC) was reduced in frontoparietal oculomotor processing areas in IXT children compared to HCs. In addition, increased cortical thickness was found in the right visual areas and bilateral IPL. These results showed that IXT-related structural and functional brain abnormalities occurred in childhood and may be related to underlying neuropathological mechanisms.

Myopic progression in school-aged children with moderate intermittent exotropia.

It is still controversial whether intermittent exotropia (IXT) affects myopic progression during the critical period of visual development. This study retrospectively analyzed the long-term myopic changes and the impact of IXT surgery on myopic progression in school-aged children with moderate IXT. The medical records of 65 children from 5 to 13 years old with or without IXT between 2015 and 2021 were retrospectively reviewed. Patients whose spherical equivalent refraction (SER) were less than -3.00 diopter (D) were included and divided into three groups: IXT surgery group (Group A), which comprised 22 IXT patients who received IXT surgery, IXT observation group (Group B), which comprises 19 IXT patients who only received long-term observational follow-up; and normal control group (Group C), which comprised 24 normal controls without IXT. The main outcome measurement was the rate of myopic progression, which was defined as the mean myopic shift in SER per year. The 3- and 5-years long-term follow-up rates of myopic progression were -0.47 ± 0.28 D per year and -0.48 ± 0.23 D per year respectively in Group B, and those were significantly slower than that in Group C (-0.73 ± 0.32 D per year and -0.76 ± 0.19 D per year respectively). However, there was no significant difference in the rate of myopic progression between Group A and B or between Group A and C. Moderate IXT may have lower rate of myopic progression in school-aged children. Whether IXT surgery influence the rate of myopic progression still needs further study.

Survey of Surgical Management in Intermittent Exotropia

Purpose: To obtain an overview of the surgical practices for the management of intermittent exotropia among experienced surgeons.Methods: We conducted a survey of members of the Korean Association for Pediatric Ophthalmology and Strabismus, who had experience of &gt; 15 years in strabismus surgery, via e-mail. Surgical methods for basic-type intermittent exotropia, angle of deviation for determining the surgical dose, reasons for surgical dose adjustment, and the postoperative target angle of deviation were analyzed.Results: Bilateral lateral rectus recession was preferred over unilateral recession and resection for basic-type intermittent exotropia with or without a dominant eye. The preoperative maximum angle of deviation was preferred for determining the surgical dose by 56% of the participants. Two-thirds of the participants preferred to reduce the surgical dose in specific circumstances, lateral incomitancy being the most common reason. In case of true divergence excess-type intermittent exotropia, 47.7% of the participants reduced the surgical dose. The most preferred target angle of deviation at 1 day postoperatively was 11-15 prism diopter esodeviation, as reported by 40% of the participants.Conclusions: Although experienced surgeons had different surgical preferences for intermittent exotropia, a general trend was found. This survey may be a useful reference for beginners in strabismus surgery.

Functional changes in fusional vergence-related brain areas and correlation with clinical features in intermittent exotropia using functional magnetic resonance imaging.

To explore the functional changes of the frontal eye field (FEF) and relevant brain regions and its role in the pathogenesis of intermittent exotropia (IXT) children via functional magnetic resonance imaging (fMRI). Twenty-four IXT children (mean age, 11.83 ± 1.93 years) and 28 normal control (NC) subjects (mean age, 11.11 ± 1.50 years) were recruited. During fMRI scans, the IXT children and NCs were provided with static visual stimuli (to evoke sensory fusion) and dynamic visual stimuli (to evoke motor fusion and vergence eye movements) with binocular disparity. Brain activation in the relevant brain regions and clinical characteristics were evaluated. Group differences of brain activation and brain-behavior correlations were investigated. For dynamic and static visual disparity relative to no visual disparity, reduced brain activation in the right FEF and right inferior occipital gyrus (IOG), and increased brain activation in the left middle temporal gyrus complex (MT+) were found in the IXT children compared with NCs. Significant positive correlations between the fusional vergence amplitude and the brain activation values were found in the right FEF, right IPL, and left cerebellum in the NC group. Positive correlations between brain activation values and Newcastle Control Scores (NCS) were found in the left MT+ in the IXT group. For dynamic visual disparity relative to static visual disparity, reduced brain activation in the right middle occipital gyrus, left cerebellum, and bilateral IPL was found in the IXT children compared with NCs. Significant positive correlations between brain activation values and the fusional vergence amplitude were found in the right FEF and right cerebellum in the NC group. Negative correlations between brain activation values and NCS were found in the right middle occipital gyrus, right cerebellum, left IPL, and right FEF in the IXT group. These results suggest that the reduced brain activation in the right FEF, left IPL, and cerebellum may play an important role in the pathogenesis of IXT by influencing fusional vergence function. While the increased brain activation in the left MT+ may compensate for this dysfunction in IXT children.