The Outcome of Inferior Oblique Myectomy for Apparent Inferior Oblique Overaction Associated with Craniosynostosis.

Purpose: Strabismus in patients with craniosynostosis is common, but surgical correction of strabismus in these patients remains challenging. We report our findings in 6 patients (4 of whom were Korean) with craniosynostosis who underwent strabismus surgery to specifically address V-pattern horizontal strabismus with moderate-to-severe inferior oblique (IO) overaction, using IO myectomy at a single tertiary hospital between 2005 and 2016. Materials and. Methods: We recorded preoperative characteristics including sex, age, type of strabismus, versions grading, refractive error, and visual acuity. The grading of cyclorotation of horizontal rectus muscles by V-pattern categorized using coronal computed tomography (CT) imaging. Results: Of the six patients, exodeviation was found in four patients and vertical deviation in two patients in primary position. One patient had both horizontal and vertical strabismus. Available computed tomography imaging showed that V-patterns were category 1 (mild) in 2 patients, category 2 (moderate) in 1 patient, and category 3 (severe) in 2 patients. Complete success was defined as absence of IO overaction any more. Overall complete success rate of IO myectomy was 83.3 %. Conclusion: IO myectomy appeared to have some benefits in V-pattern horizontal strabismus with moderate-to-severe inferior oblique (IO) overaction in patients with craniosynostosis.

Surgical Outcome of Inferior Oblique Myectomy versus Recession-Anteriorization in the Treatment of Inferior Oblique Overaction.

Purpose: This study aimed to compare the surgical outcome of inferior oblique myectomy, IOM versus inferior oblique recession-anteriorization, IORA in the treatment of inferior oblique overaction, IOOA. Patients and Methods: A retrospective chart review was performed over a 12-year period, from 2009 to 2021. Eighty-nine patients diagnosed with IOOA who underwent IOM or IORA were included. The primary outcome was postoperative residual IOOA (grade 0 to +4) and percentage favorable outcome, defined as IOOA grade ≤1+ at 6 months post operation, in each group. The outcomes were compared between the two surgical procedures (IOM and IORA). The secondary outcome was the percentage of postoperative anti-elevation syndrome cases for each surgical procedure. Results: The median age at the time of surgery was 10.50 years (interquartile range, IQR: 2.83 to 28.33) in the IOM group and 5.08 years (IQR: 2.75 to 29.42) in the IORA group. The favorable outcome at 6 months was 90.91% in the IOM group, which was lower than the 95.74% in the IORA group but the difference was not statistically significant (P-value = 0.390, 95% CI: 0.07-2.82). The only surgical complication, anti-elevation syndrome, was detected in 3.77% of IOM cases and 5.80% of IORA cases, with an odds ratio of 0.64 on comparing the IOM group to the IORA group (P-value = 0.611, 95% CI: 0.11-3.62). Conclusion: These two weakening procedures are effective for treating IOOA. Although IORA seemed slightly superior to IOM in terms of favorable outcomes, the difference was not statistically significant. Moreover, the myectomy procedure was easier, was less time-consuming, had a lower risk of globe perforation and presented fewer complications such as anti-elevation syndrome.

Evaluation of graded recession of inferior oblique muscle for correction of different grades of V-pattern strabismus.

BACKGROUND: V pattern identification is essential for proper strabismus management. Graded recession is a tailored approach to treat inferior oblique overaction (IOOA). The aim is to evaluate the efficacy of graded recession of inferior oblique muscle for correction of different grades of V pattern. METHODS: Forty patients from 3 to 18 years old with V pattern strabismus and primary IOOA were evaluated by prism cover test to assess the grade of IOOA and amplitude of V-pattern. Graded recession of IO muscle depends on the amplitude of the V-pattern and degree of IOOA. Eight mm recession for amplitude 15 PD to 20 PD and mild IOOA (10 PD-15 PD or + 1) ,10 mm recession for amplitude 20-30 PD and moderate IOOA (15-25 PD or + 2) and maximum recession for amplitude more than 30 PD and marked IOOA (≥ 25 PD or + 3). Simultaneous correction of the horizontal deviation was performed. Follow up after I week,1 month ,3 month and 6-month. Trial Registration Number (TRN) (NCT05786053) on 23/3/2023. RESULTS: The mean age of the study patients was 9 ± 4.261. Twenty patients (50%) had V-pattern esotropia, 12 (30%) exotropia, 4 (10%) orthotropic and four (10%) had Dissociated vertical deviation (DVD). Four cases 10% were of grade 1, 20 cases (50%) grade 2 and 16 cases (40%) were of grade 3. Of eighty eyes, 66 eyes (82.5%) were fully corrected with no residual IOOA, and 14 eyes (17.5%) were under corrected. V-pattern was corrected in 28 cases 70% and only 12cases (30%) had residual V-pattern grade 1. CONCLUSIONS: Graded recession is an effective procedure for correction of V pattern strabismus with various grades of primary inferior oblique overaction. It can be tailored according to the the degree of IO overaction which is significantly related to the grade of V pattern. The 8 mm recession for IO was significantly related to recurrence or inadequate break of the V pattern in our studied cases. The grade of IOOA correlates with the amplitude of V-pattern. The amount of recession was planned according to preoperative IOOA and grade of V-pattern with frequent undercorrections obtained by the standard 8 mm recession. A + 2 overaction merits a 10-mm recession of the inferior oblique. A + 3 or + 4 overaction merits a 14-mm maximal recession.

Decrease of over-elevation in adduction after surgery of medial rectus muscles in partially refractive accommodative esotropia.

SIGNIFICANCE: The course of over-elevation in adduction after strabismus surgery has been evaluated in a small number of research in the literature, we believe our study is the first to report the results in a specific group of esotropia (ET) patients. AIM: To report the course of postoperative over-elevation in adduction in patients who underwent surgery for horizontal deviation on the medial recti in partially accommodative ET. METHODS: The medical charts of patients who had partially accommodative ET with over-elevation in adduction were reviewed retrospectively. A scale from -4 to +4 was used to grade the oblique muscle function. Among these, 17 patients who were operated solely on the horizontal rectus muscles were identified. The primary outcome measure was the degree of improvement in over-elevation in adduction after medial rectus surgery. RESULTS: Nine (52.9%) of the 17 patients (mean age: 5.18 ± 2.24 months) were males and 8 (47.1%) were females. The mean follow-up period was 17.06 ± 15.32 months. Overall, 15 patients (88.2%) achieved surgical success. The mean inferior oblique overaction was found 1.44 ± 0.56 preoperatively and the final postoperative mean inferior oblique overaction was 0.53 ± 0.51 (P = 0.001). Postoperative over-elevation in adduction after 3 months was significantly decreased compared to the preoperative value (P = 0.003, P = 0.001, P = 0.001 at 3rd and 6th months and final visits respectively). CONCLUSION: Over-elevation in adduction accompanying partially refractive accommodative ET seems to regress after medial rectus weakening surgery. This finding should be considered in the presurgical evaluation of these patients.

Evaluation of the effect of unilateral and bilateral inferior oblique myectomy on fundus torsion in primary and secondary inferior oblique overaction.

OBJECTIVE: This article evaluates the effects of unilateral and bilateral inferior oblique myectomy (IOM) on fundus torsion in primary and secondary inferior oblique overaction (IOOA). METHODS: This study analyzed 230 OCT images of 53 eyes of 32 patients who had undergone IOM by a single surgeon in the last two years. The disc-foveal angle (DFA) was calculated by digitally measuring the angle between the horizontal line passing through the geometric center of the optic disc and the curved line connecting the fovea to the geometric center of the optic disc. DFA was classified into intorsion, normal torsion, and extortion. The DFA was measured from the OCT images before the operation in the first week, first month, third month, and sixth month. RESULTS: When all the patients in our study were evaluated together, IOM statistically reduced the mean DFA in the third month (p=0.00). The DFA was higher in the secondary IOOA group than in the primary IOOA group (p=0.24). Bilateral IOM statistically significantly reduced DFA in the third month (p=0.00) and decreased the DFA difference between the two eyes in the third month (p=0.583). Unilateral IOM increased the DFA, rather than decreasing it, in the first week in operated eyes (p=0594) and increased the DFA difference between the two eyes after surgery (p=0.477). When we evaluated the localization of the macula as an intorsion, normal intorsion, or extortion, the extortion decreased from 36 to nine in the third month after bilateral IOM, and intorsion was seen in only two. Unilateral surgery did not significantly change fundus torsion in primary IOOA, and it caused intorsion in 3 of 6 (50%) operated eyes in secondary IOOA. CONCLUSION: Although unilateral IOM provides a clinical improvement in secondary IOOA, it increases the difference in DFA between both eyes and causes intorsion in 50% of patients. Masked IOOA was detected in 3 of 11 (27.3%) patients who underwent unilateral IOM. When deciding on unilateral surgery, the possibility of increased DFA difference between both eyes, intorsion in the operated eye, and masked IOOA in the other eye should be considered.

Apert Syndrome - caveats of squint management.

Apert Syndrome (AS) is a rare form of acrocephalosyndactyly. The aim of the manuscript was to underline the challenging squint management in a case of Apert Syndrome. A 1.5-year-old male with craniosynostosis, diagnosed at birth, with history of incomplete closure of eyes, more so in the right eye, and squinting of left eye since birth, was brought to eye OPD by the mother. Presence of acrocephaly, prominent forehead with bony irregularity, chin down with left head tilt, fused cervical vertebrae, marked proptosis, cleft palate, dental anomaly and syndactyly confirmed the diagnosis of AS. Old serial photographs of the child were examined to look for progression of squint and proptosis. Squint evaluation revealed 70-75 PD exotropia with 10PD right hypertropia in primary gaze. The right hypertropia increased further in the left gaze, whereas a left hypertropia was noted in the right gaze. The patient underwent bilateral LR recession of 9 mm with full muscle width transposition (upshift) with Inferior Oblique recession of 4:1 mm in the right eye and 3:2 mm in the left eye. Post-operative follow-up after 2 months showed that V pattern collapsed with residual exotropia of 20 PD. Post-operative follow-up after 1 year showed improvement in head posture with pattern collapsed. However, recurrent exotropia was noted on evaluation, for which bilateral medial recti resection was done later. The management of squint in AS and other craniosynostosis poses a multitude of challenges for the ophthalmologists. Frequent follow-ups are needed in patients with AS for the timely management of its ocular manifestations and better visual rehabilitation.

Occurrence and subsequent development of vertical deviations in patients treated surgically for infantile esotropia.

Purpose: The purpose of this study was to evaluate the onset of dissociated vertical deviation (DVD) and inferior oblique overaction (IOOA), their subsequent development, and their correlation with pre and postoperative parameters. Methods: Medical records of patients with infantile esotropia who underwent surgery between 2005 and 2017 were retrospectively reviewed. DVD and IOOA were measured before and after surgery. Patients were divided into two groups based on horizontal and vertical deviation at the time of presentation: those with infantile esotropia only (group A) and patients with infantile esotropia who developed vertical deviation (group B). Results: Out of a total of 102 patients, DVD occurrence was seen in 53 patients (51.9%) and IOOA was seen in 50 patients (48.04%). DVD was seen in 22 patients at the time of initial examination and in 31 patients postoperatively. IOOA at presentation was seen in 45 patients (44.1%) and 5 patients (8.8%) postoperatively. No statistical difference was found in the age of surgery, angle of deviation, mean follow-up, and mean refractive error within both groups. The postoperative motor outcome was statistically comparable between the two groups (P = 0.29). Sensory outcomes of fusion (P = 0.048) and stereopsis (P-value = 0.00063) were better in group A. Conclusion: No correlation was found between the age of occurrence and development of vertical deviation with refractive error, angle of deviation, age, or type of surgery. We found that motor outcomes are not affected but sensory outcomes are affected in patients with vertical deviations. This indicates that DVD and IOOA are developed due to inherent disruption of fusion and stereopsis.

Pre- and postsurgical measurements in patients with strabismus sursoadductorius a retrospective study.

PURPOSE: Strabismus sursoadductorius is the most common strabismus of the oblique eye muscles. The changes in squint angle, elevation in adduction, abnormal head posture and binocular vision were collected to get an overview of the results at the largest clinic in Austria. METHODS: This study is a retrospective study. The orthoptic and ophthalmologic parameters of 102 patients who were treated in the Department of Ophthalmology and Optometry between January 2017 und September 2020 were collected and statistically analysed. RESULTS: The mean age was 12.2 ± 14.8 years. The squint angle changed from 18.3 ± 6.3 presurgical to 13.4 ± 9.7 (p = 0.09) with Hirschberg measurement. The squint angle changed from 12.5 ± 7.7 to 6.7 ± 4.9 (p < 0.01) at distance and from 12.5 ± 7.6 to 6.1 ± 4.5 (p < 0.01) at near with the prism covertest. Elevation in adduction showed a highly significant change (p < 0.01) from 15 ± 5.6 to 1.4 ± 2.8 degrees on average postsurgical. In binocular vision at distance there was also a highly significant (p < 0.01) change with 21.6% to postsurgical 37.3% positive tests. At near, the positives also increased significantly (p = 0.01) from 32.4% to 39.2%. There was no significant change in stereo vision (p = 1.0). Presurgical 52.9% of the sample had an abnormal head posture, postsurgical it was 38.2%, this change is also highly significant (p < 0.01). CONCLUSION: The change was significant to highly significant for most parameters (i.e., squint angle, elevation in adduction, and abnormal head posture).

Automated photographic analysis of inferior oblique overaction based on deep learning.

Background: Inferior oblique overaction (IOOA) is a common ocular motility disorder. This study aimed to propose a novel deep learning-based approach to automatically evaluate the amount of IOOA. Methods: This prospective study included 106 eyes of 72 consecutive patients attending the strabismus clinic in a tertiary referral hospital. Patients were eligible for inclusion if they were diagnosed with IOOA. IOOA was clinically graded from +1 to +4. Based on photograph in the adducted position, the height difference between the inferior corneal limbus of both eyes was manually measured using ImageJ and automatically measured by our deep learning-based image analysis system with human supervision. Correlation coefficients, Bland-Altman plots and mean absolute deviation (MAD) were analyzed between two different measurements of evaluating IOOA. Results: There were significant correlations between automated photographic measurements and clinical gradings (Kendall's tau: 0.721; 95% confidence interval: 0.652 to 0.779; P<0.001), between automated and manual photographic measurements [intraclass correlation coefficients (ICCs): 0.975; 95% confidence interval: 0.963 to 0.983; P<0.001], and between two-repeated automated photographic measurements (ICCs: 0.998; 95% confidence interval: 0.997 to 0.999; P<0.001). The biases and MADs were 0.10 [95% limits of agreement (LoA): -0.45 to 0.64] mm and 0.26±0.14 mm between automated and manual photographic measurements, and 0.01 (95% LoA: -0.14 to 0.16) mm and 0.07±0.04 mm between two-repeated automated photographic measurements, respectively. Conclusions: The automated photographic measurements of IOOA using deep learning technique were in excellent agreement with manual photographic measurements and clinical gradings. This new approach allows objective, accurate and repeatable measurement of IOOA and could be easily implemented in clinical practice using only photographs.

Spontaneous Recovery of Inferior Oblique Overaction in Three Saudi Children: A Case Report.

The inferior oblique muscle overaction (IOOA) results in eye elevation on adduction, head tilt, difficulty in reading/writing, and changing ocular alignments in different gazes. Surgical correction is the management. We present two cases of bilateral and one case of unilateral IOOA that resolved spontaneously, and surgery differed. There was no IOOA six months after diagnosis. A sustained resolution IOOA following correction of hyperopia, improvement of vision, and esotropia correction possibly leading to rebalancing and maturing of extraocular muscles. Ophthalmologists should refer all IOOA cases to strabismologists, should not hurry to operate, counsel parents, and monitor a child's ocular movements.

Transposición del vientre del oblicuo inferior sin desinserción en el tratamiento de la hipertropia en aducción / Transposition of the inferior oblique muscle belly without disinsertion for overshoot in adduction treatment

Propósito Analizar la eficacia y la seguridad de la transposición del oblicuo inferior con miopexia en pacientes con hiperfunción primaria o secundaria del oblicuo inferior leve-moderada, con o sin diplopía. Método Estudio observacional retrospectivo de 12 pacientes tratados con dicha técnica entre octubre de 2018 y septiembre de 2021. Se suturó el oblicuo inferior a esclera a 5mm posterior a la inserción temporal del recto inferior. Todos tenían desviación vertical de pequeño ángulo (media ±DE: 4,42±1,62) en posición primaria (≤6 dioptrías prismáticas [dp]), hipertropia en aducción leve-moderada y 10 tenían diplopía. Los diagnósticos fueron: paresia del IVnervio (9), DVD (1) e hipertropia en aducción unilateral (2). De los 12 casos, 7 presentaban tortícolis, 2 torsión subjetiva y 2 torsión objetiva. Resultados La edad media de la muestra fue 46,86±25,1 años (50% hombres). De los 10 casos con diplopía, en 9 se resolvió. La desviación vertical media final en mirada al frente fue: 1,5dp ±2,93 (p=0,001). De 7 casos con hipertropia en aducción leve, en 3 desapareció y 4 quedaron igual. De 5 casos con hipertropia en aducción moderada, 2 mejoraron a leves y en 3 desapareció. El tortícolis se resolvió en 5 casos, y en otros 2 mejoró. El tiempo de seguimiento medio fue de 14,08±8,05 meses. No se registraron hipercorrecciones. Conclusiones La transposición del oblicuo inferior con miopexia es una nueva técnica eficaz y segura en pacientes con leve-moderada hipertropia en aducción e hipertropia de pequeño ángulo, con o sin diplopía (AU)

Purpose To evaluate the efficacy and safety of inferior oblique muscle transposition and myopexy in patients with mild/moderate inferior oblique muscle overaction, with or without diplopia. Method We retrospectively analysed data for the 12 patients who underwent the technique. Data were collected from October 2018 to September 2021. Surgery was performed by suturing the inferior oblique belly to the sclera at 5mm posterior to the temporal end of the inferior rectus. All 12 patients had mild hypertropia (≤6 prism diopters [pd]) in primary position and mild/moderate inferior oblique overaction. Mean preoperative hypertropia was 4.42pd ±1.62. Diplopia was recorded in 10 cases. The diagnoses were fourth nerve paresis (9), unilateral primary inferior oblique overaction (2) and dissociated vertical deviation (1). Torticollis was observed in 7 cases, 2 had subjective torsion and 2 objective torsion. Results Mean age was 46.86±25.1 years (50%: men). Diplopia resolved in 9 of the 10 cases. The mean final vertical deviation was 1.5±2.93 (P=.001) pd in straight gaze. Of 7 mild overshoot in adduction, it disappeared in 3 and 4 remained the same. Of 5 moderate overshoot in adduction, 2 improved to mild and 3 disappeared. Torticollis was eliminated in 5 patients and improved in another 2. Mean time from surgery was 14.08±8.05 months. There were no overcorrections Conclusions Inferior oblique muscle transposition with myopexy is a safe and effective procedure in patients with mild-to-moderate inferior oblique muscle overaction and small-angle hypertropia, with or without diplopia (AU)

Inferior Oblique Anterior Transposition versus Myectomy for Inferior Oblique Overaction: Systematic Review and Meta Analysis.

The objective of this study was to compare the outcomes of inferior oblique anterior transposition (IOAT) versus inferior oblique myectomy (IOM) in patients with primary inferior oblique overaction (IOOA) or secondary IOOA to superior nerve palsy. A systematic review and meta-analysis were performed using the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) Guidelines and an electronic search was conducted to identify studies comparing IOAT versus IOM for IOOA. Residual inferior oblique function, reduction in hypertropia and post-operative complications were identified as primary outcomes. Secondary outcomes included superior oblique function, head tilt improvement, effect on the contralateral eye, operation time and macular changes. The analysis was based on fixed or random-effects modelling. Eleven studies enrolling 729 patients were identified. Inferior oblique function was not significantly different between both interventions, namely the elimination of IOOA (Odds Ratio[OR] = 0.97, P = 0.97), reduction in IOOA (Mean Difference[MD] = -0.06, P = 0.68), post-operative inferior oblique under-action (OR = 1.06, P = 0.83) and residual overaction (OR = 0.71, P = 0.15). Similarly, no significant difference was noted between both groups in reducing hypertropia. Regarding post-operative complications, no significant difference was observed, including the incidence of anti-elevation syndrome (P = 0.10). No significant difference was noted regarding superior oblique function, improvement in head tilt, effect on the contralateral eye and macular changes, although surgical time was shorter in the IOM group. In conclusion, IOAT and IOM are both effective surgical procedures in the management of IOOA as they produced comparable outcomes in the improvement in hypertropia, post-operative inferior oblique function and incidence of complications.

Transposition of the inferior oblique muscle belly without disinsertion for overshoot in adduction treatment.

PURPOSE: To evaluate the efficacy and safety of inferior oblique muscle transposition and myopexy in patients with mild/moderate inferior oblique muscle overaction, with or without diplopia. METHOD: We retrospectively analysed data for the 12 patients who underwent the technique. Data were collected from October 2018 to September 2021. Surgery was performed by suturing the inferior oblique belly to the sclera at 5 mm posterior to the temporal end of the inferior rectus. All 12 patients had mild hypertropia (≤6 prism diopters [pd]) in primary position and mild/moderate inferior oblique overaction. Mean preoperative hypertropia was 4.42 pd ±â€¯1.62. Diplopia was recorded in 10 cases. The diagnoses were fourth nerve paresis (9), unilateral primary inferior oblique overaction (2) and dissociated vertical deviation (1). Torticollis was observed in 7 cases, 2 had subjective torsion and 2 objective torsion. RESULTS: Mean age was 46.86 ±â€¯25.1 years (50%: men). Diplopia resolved in 9 of the 10 cases. The mean final vertical deviation was 1.5 ±â€¯2.93 (p = 0.001) pd in straight gaze. Of 7 mild overshoot in adduction, it disappeared in 3 and 4 remained the same. Of 5 moderate overshoot in adduction, 2 improved to mild and 3 disappeared. Torticollis was eliminated in 5 patients and improved in another 2. Mean time from surgery was 14.08 ±â€¯8.05 months. There were no overcorrections. CONCLUSIONS: Inferior oblique muscle transposition with myopexy is a safe and effective procedure in patients with mild-to-moderate inferior oblique muscle overaction and small-angle hypertropia, with or without diplopia.

Differences in gene expression between the primary and secondary inferior oblique overaction.

Background: This study sought to define different adaptive changes in the molecular levels of the overacting inferior oblique muscle in primary and secondary inferior oblique overaction. Methods: The inferior oblique muscles of patients with congenital superior oblique palsy (SOP) and those of patients with congenital esotropia were collected during surgery. RNA-seq technology was performed to detect the differentially expressed genes (DEGs) between the two groups. A comprehensive analysis of the gene expression profiles was then conducted, including the identification of DEGs, a Gene Ontology (GO) analysis, and a gene set enrichment analysis (GSEA). Finally, a protein-protein interaction (PPI) network was constructed with Search Tool for the Retrieval of Interacting Genes/Proteins (STRING) and Cytoscape software. Results: We identified 221 DEGs, of which 104 were significantly upregulated and 117 were downregulated in the SOP group. Additionally, several isoforms of the myosin heavy chain (MyHC) gene were found to be significantly and differentially expressed in the SOP group, including 3 upregulated fast-twitch MyHC isoforms (i.e., MYH1, MYH4, and MYH13) and 1 downregulated slow-twitch MyHC isoform (i.e., MYH3). The GO analysis indicated that the upregulated DEGs were mainly enriched in the muscle system process and muscle contraction. The GSEA analysis revealed that the upregulated pathways of ribosome, proteasome, oxidative phosphorylation, fatty acid metabolism, viral myocarditis, and cardiac muscle contraction were enriched. Conclusions: Our findings provide insights into the different molecular changes of inferior oblique muscle overaction secondary to SOP and suggest the potential pathological mechanisms of inferior oblique overaction (IOOA) in SOP. The results suggest that upregulated fast-twitch MyHC isoforms and downregulated slow-twitch MyHC isoform in SOP may contribute to the increased force of its inferior oblique muscle.

Effect of bilateral inferior oblique partial myectomy on V pattern exotropia with inferior oblique overaction.

PURPOSE: To compare the effect of bilateral inferior oblique partial myectomy on V-pattern exotropia patients with bilateral symmetric inferior oblique overaction (IOOA) and asymmetric IOOA. METHODS: This was a retrospective study including 53 V-pattern exotropia patients with bilateral IOOA of all grades who underwent bilateral inferior oblique partial myectomy. Success was defined as the elimination of the IOOA and the collapse of the V pattern at the final follow-up. The fovea-disc angle (FDA) and V-pattern exotropia were compared before and after surgery. RESULTS: This study included 53 V-pattern exotropia patients, containing 29 patients with symmetric IOOA (Group I) and 24 patients with asymmetric IOOA (Group II). The last follow-up ranged from 3 to 16 months (mean of 5 months). After myectomy, 3 eyes in Group I and 2 eyes in Group II were observed with residual grade 1 IOOA. The surgical success rates of IOOA correction in Group I and Group II were 96% and 95%, respectively. The difference was not statistically significant (P = 0.808). V-pattern exotropia collapsed with residual 2 (min. 0, max. 6) PD for Group I and 2 (min. 0, max. 10) PD for Group II, and there was a statistically significant difference between pre- and postoperative V-pattern exotropia in the two groups (P = 0.000). No inferior oblique (IO) underaction or antielevation syndrome (AES) was found in either group. The average preoperative FDA of the right eye and the left eye was (8.93 ± 4.34)° and (10.86 ± 4.27)° in Group I and (9.08 ± 4.92)° and (11.00 ± 5.69)° in Group II. There was a significant difference in preoperative FDA between the right eye and the left eye in the two groups (Group I p = 0.029; Group II p = 0.038). CONCLUSIONS: Bilateral inferior oblique partial myectomy can bring "symmetric" effectiveness in the correction of IOOA and FDA. It can potentially be used as a safe and successful treatment for V-pattern exotropia with bilateral IOOA. In addition, the FDA may be a promising index for evaluating fundus extorsion.

Inferior oblique belly transposition in the treatment of mild inferior oblique overaction with small angle vertical strabismus / 国际眼科杂志(Guoji Yanke Zazhi)

@#AIM:To observe the effect of inferior oblique belly transposition(IOBT)in unilateral mild inferior oblique overaction with small angle vertical stabismus.<p>METHODS: The data of patients who underwent IOBT in our hospital from September 2019 to August 2021 were analyzed retrospectively. Inclusion criteria targeted patients with mild inferior oblique overaction(2+ and below)and small angle incomitant vertical strabismus(4-9PD). The horizontal deviation and vertical deviation in both primary and lateral gazes were measured, and the degree of inferior oblique overaction and fovea-disc angle(FDA)were also evaluated preoperatively and postoperatively.<p>RESULTS: A total of 16 cases(16 eyes)were included, aged 4-39 years. One case was 5a postoperative congenital esotropia with secondary unilateral inferior oblique overaction by mild superior oblique palsy, whereas 15 patients had monocular primary inferior oblique overaction with horizontal strabismus. The follow-up was 3-6mo. The mean improvement of inferior oblique overaction was 2.00(1.25, 2.00)grade from +2.00(2.00, 2.00)preoperatively to 0.00(0.00, 0.00)postoperatively, the difference was statistically significant(<i>Z</i>=-3.70, <i>P</i><0.001). The horizontal strabismus decreased from 69.13±25.86PD preoperatively to 2.75±2.59PD postoperatively(<i>t</i>= 9.929, <i>P</i><0.001). The vertical strabismus in the primary position decreased from preoperative 7.44±1.32PD to 1.00±1.21PD postoperatively(<i>t</i>=22.335, <i>P</i><0.001), mean corrected hypertropia 6.44±1.15PD, and vertical strabismus in lateral gazes decreased from preoperative 12.44±2.73PD to 3.00±2.13PD postoperatively, mean corrected hypertropia 9.44±2.73PD, these differences were statistically significant(<i>t</i>=13.819, <i>P</i><0.001). The FDA decreased from -8.85°±6.53° preoperatively to -6.49°±7.01° postoperatively, the difference was statistically significant(<i>t</i>=-2.384, <i>P</i><0.001), with a mean reduction of 2.36°. No postoperative complications such as postoperative overcorrection or inferior oblique underaction were observed.<p>CONCLUSION:IOBT is safe and effective in correcting unilateral mild inferior oblique overaction with small angle vertical strabismus.

Inferior Oblique Recession with 5 mm Loop to Correct Vertical Deviation and Inferior Oblique Overaction Secondary to Superior Oblique Palsy.

Purpose: To evaluate the effect of augmented inferior oblique recession (recession +5 mm loop) on the vertical deviation in primary position (PP) and the inferior oblique overaction (IOOA) in patients with unilateral congenital or acquired superior oblique palsy.Patients and methods: The medical records of patients who underwent unilateral inferior oblique recession with 5 mm loop during 2012 and 2019 were retrospectively reviewed. All patients had small to moderate manifest or intermittent hypertropia in PP and overaction of the inferior oblique muscle of +2 or +3 in lateral gaze. Patients who had combined inferior rectus surgery of the contralateral eye or who had previous vertical muscle surgery were excluded.Results: A total of 26 patients were included. Of these, three patients had combined horizontal muscle surgery. In 22 patients, the superior oblique palsy was congenital or longstanding, in 4 it was acquired and stable for more than 9 months. The mean preoperative vertical deviation in PP at distance and near was 14.7Δ and 11.2Δ, respectively. The mean postoperative vertical deviation was 5.7Δ and 4.1Δ after a mean follow-up of 19 months. The IOOA improved in all patients, 16 patients had an improvement of +2 and 10 patients had an improvement of +1.Conclusion: Inferior oblique recession with a 5 mm loop is a simple and quick technique to correct small to moderate hypertropia in primary position and inferior oblique overaction in contralateral gaze in patients with congenital, longstanding or acquired superior oblique palsy without risk of overcorrection.

Effect of inferior oblique muscle belly transposition on versions and vertical alignment in primary position.

PURPOSE: To evaluate the effect of inferior oblique muscle belly transposition (IOBT) on vertical deviation (VD) in primary position and inferior oblique overaction (IOOA). METHODS: Twenty-eight patients who underwent unilateral IOBT for mild hypertropia (≤ 10△) due to unilateral IOOA were included. Surgical results regarding the correction of hypertropia, IOOA, and fovea disc angle (FDA) were analyzed and compared between groups A (VD ≤ 5△) and B (5△ < VD ≤ 10△). RESULTS: IOBT showed an overall reduction of 5.86△ (± 2.24△) of primary position VD, a mean correction of 1.00 (± 0.27) of IOOA, and an average change of 1.83° (± 3.02°) of FDA. The surgical success rate of IOBT for VD correction and IOOA elimination in all patients was 68% and 71%, respectively. The correction of VD was correlated with preoperative VD significantly (r = 0.86, p < 0.001). Consistently, IOBT demonstrated comparable efficacy in reduction of VD between group A and group B (p = 0.507). Furthermore, the two groups were comparable in the success rates for correcting VD and IOOA (both p > 0.05). None of the patients developed consecutive hypotropia, postoperative contralateral IOOA, or anti-elevation syndrome postoperatively. CONCLUSIONS: IOBT achieved satisfactory outcomes in patients with mild primary position VD (≤ 10△) that is associated with unilateral IOOA, without any risk of overcorrection of VD and contralateral IOOA for a follow-up period of up to 12 months. This procedure is considered effective and safe alternative for weakening the IO in patients with appropriate surgical indications.

Surgical outcomes and occurrence of associated vertical strabismus during a 10-year follow-up in patients with infantile esotropia.

PURPOSE: Authors analyzed long-term surgical outcomes of infantile esotropia and the occurrence of associated strabismus, inferior oblique overaction (IOOA), and dissociated vertical deviation (DVD). Clinical factors related to the occurrence of IOOA and DVD in patients with infantile esotropia were also evaluated. METHODS: Medical records of patients with infantile esotropia, who underwent surgery between 1995 and 2008, were reviewed retrospectively. Included patients were followed for at least 10 years. The incidence and age at development of IOOA and DVD were analyzed. To evaluate predisposing factors for developing IOOA or DVD, patients were divided into two groups: those with infantile esotropia only (group A) and those who developed IOOA or DVD (group B). RESULTS: A total of 122 patients were enrolled and mean follow-up period was 16.0 years (range: 10-32 years). The mean number of surgeries was 1.7 (range: 1-5), and 64 (52.5%) patients achieved optimal horizontal alignment (esotropia <10 prism diopters [PD] and orthotropia). Fifty (41.0%) patients developed IOOA at a median age of 3 years (range: 1-21 years); 54 (44.3%) developed DVD at a median age of 5 years (range: 1-25 years). Patients in group B underwent more horizontal surgeries than those in group A (P = 0.028), and favorable surgical outcomes between the two groups were not different at final visit. There were no other significant differences in clinical factors between the two groups. CONCLUSION: Approximately, 52.5% of patients achieved favorable surgical outcomes through 1.7 surgeries during the 10-year follow-up period. DVD tended to develop at a later age than IOOA, and in some cases, up to 20 years after diagnosis of infantile esotropia. To achieve favorable horizontal alignment at final visit, patients with associated vertical strabismus underwent more horizontal muscle surgeries than patients with infantile esotropia only. The presence of IOOA/DVD may affect horizontal alignment outcomes.

Inferior Oblique Overaction: The Results of Myectomy in Cases with a Primary Position Vertical Deviation Less and More Than 20 Prism Diopters.

PURPOSE: The purpose of this study is to evaluate the results of myectomy in inferior oblique overaction cases with a vertical deviation angle of <20 and ≥20 prism diopters (PD) in the primary position. METHODS: The medical records of cases with inferior oblique overaction that underwent inferior oblique myectomy for ≥6 PD hypertropia in the primary position and >+1 inferior oblique overaction were reviewed. Preoperative and postoperative examination findings and success rates were compared of cases with a deviation angle <20 PD (Group 1) and ≥20 PD (Group 2). RESULTS: The mean age of 35 (58%) female and 25 (42%) men cases of Group 1 (n = 60) were 12.8 ± 9.4 years; the mean age of 25 (58%) female and 18 (42%) male cases of Group 2 (n = 43) were 14.8 years (P = 0.340). The near hypertropia was decreased from 11 to 0.5 PD in Group 1, from 22.1 to 5.1 PD in Group 2 cases (P < 0.001). The distance hypertropia was decreased from 11.3 to 0.5 PD in Group 1 and from 23.3 to 6.1 PD in Group 2 cases (P < 0.001). The mean degree of hypertropia at near and distance was statistically significantly higher both pre- and post-operatively in Group 2 than in Group 1 (P < 0.001), and improved statistically significantly with the initial surgery in both groups (P < 0.001). The rate of the presence of stereopsis of ≥3000 s/arc and fusion, the main criteria of binocular vision (BOV), was not statistically significantly different between the Groups before (P = 0.577) and after the surgery (P = 0.678), but the presence of BOV significantly increased both in Group 1 (P < 0.001) and Group 2 (P = 0.004) postoperatively. The number of cases with surgical success was 57 (95%) and 25 (58%), respectively, in Groups 1 and 2 (P < 0.001). CONCLUSIONS: Myectomy is an effective surgical procedure that can be easily and quickly performed in inferior oblique overaction cases and has high success rates in cases with a small-to-moderate angle of deviation.