Postoperative outcome and influencing factors of strabismus surgery in infants aged 1-6 years.

PURPOSE: To evaluate the postoperative outcome of strabismus surgery performed in children aged 1-6 years by investigating the change of the preoperative angle of deviation (AOD), elevation in adduction, best-corrected visual acuity (BCVA) and refractive error. METHODS: Retrospective chart review of 62 children who received strabismus surgery between January 2018 and December 2021 at the Department of Ophthalmology and Optometry of the Medical University of Vienna. Age, sex, type of strabismus, AOD, BCVA, refractive error and visual acuity were evaluated with respect to the postoperative outcome. RESULTS: Mean follow-up was 13.55 ± 11.38 months with a mean age of 3.94 ± 1.97 years (range: 1.0-6.0) at time of surgery. 74.19% of patients (n = 46) had isolated or combined esotropia, 12.90% (n = 8) had isolated or combined exotropia and 12.90% (n = 8) had isolated strabismus sursoadductorius. Mean preoperative AOD of 15.69 ± 16.91°/15.02 ± 14.88° (near/distance) decreased to 4.00 ± 9.18°/4.83 ± 7.32° (near/distance) at final follow-up (p < 0.001). BCVA improved from 0.26 ± 0.26/0.25 ± 0.23 (left/right) to 0.21 ± 0.25/0.20 ± 0.23 (left/right) (p = 0.038). There was no significant change regarding refractive error (p = 0.109) or elevation in adduction (p = 0.212). Success rate which was defined as a residual AOD of less than 10° was 74.19% (n = 46). In 3.23% (n = 2) retreatment was necessary. CONCLUSION: Strabismus surgery in infants was shown to have a satisfactory outcome with a low retreatment rate. Surgical success rate was not linked to age, sex, type of strabismus or the preoperative parameters AOD, refractive error and visual acuity in this study.

The impact of simultaneous correction of the V pattern on the results of surgical treatment in children with intermittent exotropia.

PURPOSE: This study is to investigate the impact of the coexistence of basic intermittent exotropia and vertical incomitance in the form of the V and sub-V pattern on the results of surgical correction of intermittent exotropia. METHODS: The records of 81 pediatric patients who had surgery for intermittent exotropia and a follow-up of more than 1 year were reviewed retrospectively. They were divided into groups: a concomitant group which underwent only horizontal muscle surgery of bilateral lateral rectus recession and a V pattern group which had additional inferior oblique recession, further separated into two subgroups: ≥ 15 prism diopters (classic V pattern group) and ≥ 10 < 15 prism diopters (sub-V pattern group). The surgical outcome, deviation control, stereoacuity, and postoperative drift were assessed after 3 months and 1 year postoperatively. RESULTS: Patients with sub-V and classic V pattern intermittent exotropia showed significantly better surgical success rate (p = 0.025) and less postoperative drift (p = 0.042) than patients without vertical incomitance. One year after surgery, successful surgical outcome was achieved in 83.72% of the vertically incomitant group: 80.76% for the classic V pattern and 88.24% for the sub-V pattern group, while only in 60.53% of nonpattern patients. CONCLUSIONS: Patients operated for intermittent exotropia with a coexistent V pattern have consistently better surgical long-term results than those with only horizontal deviation. Additional inferior oblique recessions in the sub V pattern group provided excellent outcomes with no overcorrections; therefore, surgeons should consider addressing vertical incomitance even when the typical criteria for the V pattern are not met.

Investigation of the effects of single and two-muscle horizontal rectus surgeries on macular microvasculature.

PURPOSE: To investigate the changes in posterior segment hemodynamics caused by horizontal rectus muscle surgeries using the optic coherence tomography angiography (OCTA). METHODS: Patients who underwent at least one horizontal rectus recession, resection, or combination surgery were included. The patients were evaluated with an OCTA preoperatively and 30 days postoperatively. Postoperative changes in superficial capillary plexus (SCP)-vessel density (VD), deep capillary plexus (DCP)-VD, foveal avascular zone (FAZ) area and choriocapillaris (CC)-flow area parameters were examined. The mean differences (Δ) for the parameters in which significant changes were detected in the whole operated eyes group were compared between the single- and two-muscle surgery groups. RESULTS: Twenty-five eyes of 24 patients with an average age of 16.40 ± 6.75 years (5-29) were included. Of the eyes, 10 underwent single muscle recession surgery. Two-muscle surgeries were performed in 15 eyes. SCP-VD in the superior parafoveal region increased significantly postoperatively (53.23 ± 4.11% vs. 54.54 ± 3.67%, p = 0.032). For DCP-VD, there was a statistically significant increase in all zones, except the superior hemisphere and fovea regions (p < 0.05 for all). FAZ area did not change significantly (p = 0.207). There was a significant increase in the CC-flow area (2.171 ± 0.146 mm2 vs. 2.232 ± 0.115 mm2, p = 0.013). There was a significant difference between the two groups only for the Δ SCP-VD/parafovea superior value (-0.62 ± 0.98 vs. 1.57 ± 3.07, p = 0.019). CONCLUSIONS: Conventional horizontal rectus muscle surgeries may cause alterations in posterior segment hemodynamics. The number of muscles incised does not seem to greatly affect the magnitude of changes that occur. KEY MESSAGES: What is known • After conventional horizontal rectus muscle surgeries, the anterior ciliary arteries are not recanalized, instead, anterior segment blood flow is maintained by increasing the flow in the long posterior ciliary arteries. • Previous studies using Doppler ultrasonography have shown increased flow in the ophthalmic artery, central retinal artery and long posterior ciliary arteries. What is new • In this study, significant increases were observed in superficial and deep capillary plexus-vessel density and choriocapillaris-flow area parameters in the first postoperative month with optic coherence tomography angiography device. • Hemodynamic increases in both retinal and choroidal vasculature were detected in the early period after conventional horizontal rectus muscle surgeries. • The number of muscles incised does not seem to greatly affect the magnitude of changes that occur.

The distribution characteristics of strabismus surgery types in a tertiary hospital in the Central Plains region during the COVID-19 epidemic.

OBJECTIVE: This study aimed to analyze the distribution of different types of strabismus surgery in a tertiary hospital in Central China during the three-year period of the COVID-19 pandemic. METHODS: A retrospective analysis was conducted on the clinical data of strabismus patients who underwent surgery and were admitted to the Department of Strabismus and Pediatric Ophthalmology at the First Affiliated Hospital of Zhengzhou University between January 2020 and December 2022. RESULTS: A total of 3939 strabismus surgery patients were collected, including 1357 in 2020, 1451 in 2021, and 1131 in 2022. The number of surgeries decreased significantly in February 2020, August 2021, and November and December 2022. Patients aged 0-6 years accounted for 37% of the total number of strabismus surgery patientsr. The majority (60%) of all strabismus surgery patients were diagnosed with exotropia, with intermittent exotropia accounting for the highest proportion (53%). There was no statistically significant difference in the proportion of intermittent exotropia and constant exotropia during the three-year period (χ2 = 2.642, P = 0.267 and χ2 = 3.012, P = 0.221, respectively). Among patients with intermittent exotropia, insufficient convergence type was the most common form of strabismus (accounting for over 70%). Non-accommodative esotropia accounted for more than 50% of all internal strabismus cases. CONCLUSION: During the period from 2020 to 2022, the total number of strabismus surgeries in our hospital did not show significant fluctuations, but there was a noticeable decrease in the number of surgeries during months affected by the pandemic. Exotropia accounted for the highest proportion among strabismus surgery patients. Intermittent exotropia was the most common type among patients undergoing surgery for exotropia, and the most prevalent subtype was the insufficient convergence type. The age distribution of patients varied in different months, with a concentration of surgeries for strabismus patients in the 7-12 years old age group during the months of July and August each year.

Automated detection of steps in videos of strabismus surgery using deep learning.

BACKGROUND: Learning to perform strabismus surgery is an essential aspect of ophthalmologists' surgical training. Automated classification strategy for surgical steps can improve the effectiveness of training curricula and the efficient evaluation of residents' performance. To this end, we aimed to develop and validate a deep learning (DL) model for automated detecting strabismus surgery steps in the videos. METHODS: In this study, we gathered 479 strabismus surgery videos from Shanghai Children's Hospital, affiliated to Shanghai Jiao Tong University School of Medicine, spanning July 2017 to October 2021. The videos were manually cut into 3345 clips of the eight strabismus surgical steps based on the International Council of Ophthalmology's Ophthalmology Surgical Competency Assessment Rubrics (ICO-OSCAR: strabismus). The videos dataset was randomly split by eye-level into a training (60%), validation (20%) and testing dataset (20%). We evaluated two hybrid DL algorithms: a Recurrent Neural Network (RNN) based and a Transformer-based model. The evaluation metrics included: accuracy, area under the receiver operating characteristic curve, precision, recall and F1-score. RESULTS: DL models identified the steps in video clips of strabismus surgery achieved macro-average AUC of 1.00 (95% CI 1.00-1.00) with Transformer-based model and 0.98 (95% CI 0.97-1.00) with RNN-based model, respectively. The Transformer-based model yielded a higher accuracy compared with RNN-based models (0.96 vs. 0.83, p < 0.001). In detecting different steps of strabismus surgery, the predictive ability of the Transformer-based model was better than that of the RNN. Precision ranged between 0.90 and 1 for the Transformer-based model and 0.75 to 0.94 for the RNN-based model. The f1-score ranged between 0.93 and 1 for the Transformer-based model and 0.78 to 0.92 for the RNN-based model. CONCLUSION: The DL models can automate identify video steps of strabismus surgery with high accuracy and Transformer-based algorithms show excellent performance when modeling spatiotemporal features of video frames.

Investigation of alterations in retrobulbar hemodynamics and their correlation with choroidal thickness after strabismus surgery.

BACKGROUND: To evaluate the changes in retrobulbar circulation after strabismus surgery and to assess the relationship of these changes with choroidal thickness (CT). METHODS: This prospective study included 26 eyes of 26 patients who underwent strabismus surgery and 15 eyes of 15 healthy individuals as control group. The patients who had single horizontal muscle surgery were included in Group 1 (n = 14); and those who had surgery on both horizontal muscles were included in Group 2 (n = 12). Peak systolic velocity (PSV), end-diastolic velocity (EDV), resistive index (RI) and pulsatility index (PI) of ophthalmic artery (OA), posterior ciliary artery (PCA), and central retinal artery (CRA) were measured using Color Doppler Ultrasonography. Subfoveal CT was measured via Optical Coherence Tomography. All measurements were obtained preoperatively, at 1st week and 1st month after surgery. RESULTS: There were no differences regarding preoperative blood flow velocity parameters among the groups. OA RI increased significantly at 1st week and 1st month after surgery in Group 1 and 2 (P = 0.029 and P = 0.045, respectively). There was a significant increase in PCA PSV at 1st week in Group 1 (P = 0.002). There was no difference between the mean preoperative and postoperative CT among the 3 groups. A negative correlation between the percentage changes of CT and CRA EDV was found in Group 2 (P = 0.011). CONCLUSION: Single and double horizontal rectus muscle surgery have a measurable effect on retrobulbar hemodynamics but these changes do not correlate with CT.

Discharge Under Sedated Status can Decrease Postoperative Emergence Agitation in Pediatric Patients Undergoing Strabismus Surgery: A Prospective Randomized Controlled Trial.

PURPOSE: Emergence agitation (EA) is a frequent complication during emergence. The researchers aimed to investigate whether discharged pediatric patients from the postanesthesia care unit (PACU) to wards under sedated status could reduce the incidence of EA. DESIGN: Prospective randomized controlled study. METHODS: This study was conducted in 4 to 6 year old patients who had undergone strabismus surgeries. There were 100 patients randomly assigned to a sedated group who were discharged from PACU to the ward under a sedated state and regained consciousness accompanied with their parents (Group P, n = 50) and the control group who were fully awake when discharged (Group C, n = 50). The primary outcome was the incidence of EA. The secondary outcomes included rescue measure, discharge time, hemodynamic parameters at the point of discharge, 1 and 2 hours after extubation, and the parental satisfaction score. FINDINGS: The incidence of EA in Group P was significantly reduced compared to Group C (P = .023). The number of patients who needed rescue measures was higher in Group C than in Group P (P = .041). The PACU discharge time in Group P was significantly shorter than in Group C (P < .001). The heart rate of the pediatric patients in Group P was significantly lower than in Group C at the point of discharge from PACU to the ward (P = .003), while the oxygen saturation (SpO2) and the mean arterial blood pressure were comparable between the two groups (P > .05). CONCLUSIONS: Pediatric patients discharged to their parents under sedated status could reduce the incidence of EA undergoing strabismus surgery.

The preventive effect of dexmedetomidine on anesthesia complications in strabismus surgery: a systematic review and meta-analysis.

OBJECTIVE: Dexmedetomidine is a medication that has analgesic, sedative, and anti-anxiety properties. In the clinical, it is often used to prevent common complications associated with strabismus surgery, including postoperative delirium, postoperative nausea and vomiting, postoperative pain, and oculocardiac reflex. However, its effectiveness and side effects of the present studies are different. The sample sizes of the present studies on the prevention of complications of dexmedetomidine are small. Therefore, this study evaluates the efficacy of dexmedetomidine in preventing anesthesia-related complications in strabismus surgery through a systematic review and meta-analysis. METHODS: Literature was retrieved from 10 commonly used databases and randomized controlled trials published up to May 2022 were sought. The included studies compared the intervention effects of dexmedetomidine versus placebo on anesthesia-related complications in surgery. The occurrence rates of postoperative delirium, postoperative nausea and vomiting, postoperative pain, and oculocardiac reflex in patients undergoing strabismus surgery were evaluated. Statistical analyses and forest plots were generated using Review Manager and STATA software. Binary outcomes were measured using relative risk (RR) with a 95% confidence interval for each outcome. The Cochrane risk of bias tool was used to assess the bias and risk in the studies that met the inclusion criteria. RESULTS: A total of 13 articles were ultimately included in the analysis, comprising 1,018 patients who underwent strabismus surgery. The dexmedetomidine group, compared to the placebo group, demonstrated significant reductions in the incidence of postoperative delirium (RR = 0.73, P = 0.001), severe postoperative delirium (RR = 0.45, P = 0.005), postoperative nausea and vomiting (RR = 0.48, P < 0.0001), and the need for supplemental analgesia postoperatively (RR = 0.60, P = 0.004). Additionally, subgroup analysis revealed that intravenous administration of dexmedetomidine significantly reduced the incidence of oculocardiac reflex (RR = 0.50, P = 0.001). In contrast, intranasal administration of dexmedetomidine did not have a significant effect on the incidence of oculocardiac reflex (RR = 1.22, P = 0.15). There was a significant difference between the subgroups (P = 0.0005, I2 = 91.7%). CONCLUSION: Among patients undergoing strabismus surgery, the use of dexmedetomidine can alleviate postoperative delirium and reduce the incidence of postoperative nausea and vomiting, as well as postoperative pain. Moreover, intravenous administration of dexmedetomidine can lower the occurrence rate of the oculocardiac reflex.

Long-term outcomes of adjustable strabismus surgery at a Pakistani university hospital.

PURPOSE: Strabismus, whether congenital or acquired, is a common visual and cosmetic problem, especially for the young. Adjustable suture strabismus surgery is not in vogue in our country. This technique gives the surgeon a second attempt to provide a better outcome for the patients. Our objective was to assess the long-term success of adjustable strabismus surgery in terms of postoperative alignment. METHODS: We carried out a prospective study utilizing the fornix approach for adjustable strabismus surgery, in mainly horizontal, but also vertical strabismus in adults and cooperative children, to enhance the postoperative outcomes. The patient characteristics, preoperative deviation, type and pattern of strabismus, were evaluated and analyzed. The postoperative alignment was evaluated at 1 year and beyond, to assess the success of this adjustable surgery. RESULTS: This study recruited 50 adults and children with a female predominance of 39 (78%); and with the mean age being 18.34 ± 9.88 years. Exotropia was the primary diagnosis in the majority with 21 (42%) cases; with purely horizontal strabismus in 23 (46%) cases. The mean preoperative horizontal deviation was 48.76 ± 20.35 prism diopters (PD) and the mean postoperative horizontal deviation was 2.73 ± 3.63 PD. The mean preoperative vertical deviation was 4.8 ± 8.54 PD whereas the mean postoperative vertical deviation was 0.86 ± 1.73 PD. The Wilcoxon Signed Ranks test analyzed the difference between the two which was statistically significant (p = 0.000). Surgical success, defined as postoperative horizontal alignment within ≤ 10 PD of orthotropia at the end of one year or more of follow-up after surgery, was achieved in 49 (98%) cases. The average follow-up was 21.47 ± 8.7 months. CONCLUSION: Adjustable strabismus surgery has very good long-term outcomes in terms of postoperative alignment and patient satisfaction.

The efficiency of quick response code versus telephone contact for post-discharge follow-up after ophthalmic day surgery: a randomized controlled trial.

PURPOSE: To assess and compare the efficiency of quick response (QR) code versus telephone contact for post-discharge follow-up in patients receiving low-risk ophthalmic day surgery. METHODS: One hundred and sixty patients undergoing strabismus day-care surgery with general anesthesia were randomly allocated to either the intervention group using QR code (QR group) or the control group receiving telephone call (TEL group) for post-discharge follow-up. The primary outcome was the follow-up overall attendance rate on the second postoperative day. Secondary outcomes included attendance rate at the first scheduled follow-up, number of text message reminders, elapsed time and estimated cost for follow-up, omission rate of follow-up responses, and patient satisfaction. RESULTS: The overall attendance rate of follow-up was significantly higher in the QR group than that in the TEL group (97.5% vs. 87.5%, p = 0.016). As compared with the TEL group, the QR group significantly reduced the number of text message reminders with higher attendances at the first scheduled follow-up (p < 0.001, p = 0.001). Besides, the TEL group cost a median time of 258 s and a median cost of RMB 5.8 yuan to complete a follow-up consultant, but was associated with a significantly high omission rate of follow-up responses comparing to the QR group (p = 0.002). Patient satisfaction was comparable between two groups. CONCLUSION: QR code follow-up can be more efficient than traditional telephone contact in assessing the post-discharge recovery after strabismus day surgery, which provides a safe and intuitively alternative follow-up pathway for identifying issues that may necessitate further clinical care for more low-risk ophthalmic day surgeries.

Anesthesia for ophthalmic surgery: an educational review.

PURPOSE: Selecting an anesthetic agent for ophthalmic surgery has crucial implications for the surgeon, anesthesiologist, and patient. This educational review explores the common classes of anesthesia used in ophthalmology. Additionally, we discuss the considerations unique to cataract, glaucoma, strabismus, orbital, oculoplastic, and ocular trauma surgeries. METHODS: A comprehensive Embase search was performed using combinations of the subject headings "anesthesia", "eye surgery", "ophthalmology" and "cataract extraction", "glaucoma", "strabismus", "vitreoretinal surgery", "retina surgery", "eye injury", and "eyelid reconstruction". RESULTS: Topical anesthetics are the most commonly used form of ocular anesthesia, used in both an office and surgical setting, and carry a minimal side effect profile. Notably, topical anesthetics offer analgesia, but do not provide akinesia or amnesia. Regional blocks, such as are sub-Tenon's, peribulbar, and retrobulbar blocks, are used when akinesia is required in addition to analgesia. Recently, sub-Tenon's blocks have recently gained popularity due to their improved safety profile compared to other regional blocks. General anesthesia is considered for long, complex surgery, surgery in patients with multiple comorbidities, surgery in young pediatric patients, or surgery in patients intolerant to local or regional anesthetic. CONCLUSION: Anesthetizing the eye has rapidly evolved in recent years, supporting the safety, efficacy and comfort of ocular surgery. Since there are many viable options of anesthetics available for ophthalmic surgery, a robust understanding of the patients needs, the skill of the surgical team, and surgery-specific factors ought to be considered when creating an anesthetic plan for surgery.

Adjustable Suture Technique Is Associated with Fewer Strabismus Reoperations in the Intelligent Research in Sight Registry.

PURPOSE: To compare the reoperation rates after strabismus surgery with and without the adjustable suture technique. DESIGN: Retrospective cohort study. PARTICIPANTS: Patients 18 years of age or older in the Intelligent Research in Sight (IRIS®) Registry who underwent strabismus surgery between January 1, 2013, and December 31, 2018. METHODS: Data were collected from the electronic health records of practices participating in the IRIS Registry. The primary exposure of interest was use of the adjustable suture technique, identified by Current Procedural Terminology coding. MAIN OUTCOME MEASURES: The primary outcome was repeat strabismus surgery within 1 year of initial strabismus surgery. Odds ratios (ORs) were derived from a multivariable logistic regression model evaluating the association between the use of adjustable sutures and reoperation rate, adjusting for patient demographics and surgical factors. RESULTS: A total of 34 872 patients who underwent strabismus surgery during the study interval were identified: 72% underwent horizontal muscle surgery, 17% underwent vertical muscle surgery, and 11% underwent combined horizontal and vertical muscle surgery. Adjustable sutures were used in 18% of patients. The overall reoperation rate within 1 year of strabismus surgery was 7.7%. The 1-year reoperation rate was 6.0% for patients treated with adjustable sutures and 8.1% for patients treated without adjustable sutures (P < 0.001). The multivariable regression model revealed a statistically significant 30% decrease in the odds of reoperation within 1 year of surgery when adjustable sutures were used (OR, 0.70; 95% confidence interval [CI], 0.62-0.78), a 40% increase in those with a history of prior strabismus surgery (OR, 1.40; 95% CI, 1.28-1.53), and a 9% increase per decade of age at surgery (OR, 1.09; 95% CI, 1.06-1.11). CONCLUSIONS: In adults cared for in practices participating in the IRIS Registry, the adjustable suture technique was associated with a significantly lower reoperation rate within 1 year of undergoing horizontal or combined horizontal and vertical strabismus surgery. Adjustable suture use in vertical strabismus surgery alone did not reduce the 1-year reoperation rate significantly. A history of prior strabismus surgery was associated with increased odds of reoperation.

Ocular hypertension in patients with active thyroid-associated orbitopathy: a predictor of disease severity, particularly of extraocular muscle enlargement.

The purpose was to ascertain if any relation exists between the elevated intraocular pressure (IOP) in patients with thyroid-associated orbitopathy (TAO) in active stage and the severity of extraocular muscle involvement and the extent of exophthalmos. METHODS: A total of 96 eyes and orbits of 48 adult patients with active TAO were investigated. All patients underwent magnetic resonance imaging of the orbit and measurement of all extraocular recti muscles (EOM). The obtained data was divided into two groups according to the IOP value: normal IOP ≤ 21 mmHg; n = 47 and elevated IOP with IOP > 21 mmHg; n = 49, and analyszed. RESULTS: A significant difference was found in the short diameter of medial rectus and inferior rectus muscles and in the sum of short parameters of all EOM. All these parameters were significantly higher in the elevated IOP group. Motility restriction in at least one gaze direction was also significantly more frequent (p < 0.0001) in the elevated IOP group. A positive moderate correlation was found between IOP and the sum of short parameters of EOM (r = 0.496). No correlation was found between the IOP and exophthalmos values (r = 0.267). During the follow-up, the frequency of strabismus surgery and orbital decompression was significantly higher in the elevated IOP group (p = 0.003; p = 0.002). CONCLUSION: Elevated IOP in the active TAO stage particularly correlates with extraocular muscle involvement. These patients are also more likely to require orbital decompression and strabismus surgery.

Surgical outcomes of adjustment on recessed lateral rectus muscle versus resected medial rectus muscle for intermittent exotropia.

BACKGROUND: To evaluate the effectiveness of resected muscle adjustment compared with the recessed muscle adjustment in patients with intermittent exotropia. METHODS: This retrospective clinical investigation analyzed the data of patients who underwent strabismus surgery with adjustment. Patients who were followed-up for at least one and half year after adjustment were enrolled. They were divided into two groups; patients who underwent adjustment on recessed lateral rectus muscle (LR-Adj group) and adjustment on resected medial rectus muscle (MR-Adj group). Postoperative changes were compared. Surgical success was defined as horizontal deviation < 5 prism diopters (PD) esodeviation and < 10 PD exodeviation on distance measurement at 1.5 years postoperatively. RESULTS: Forty patients were included; LR-Adj group included 21 and MR-Adj group included 19 patients. The mean esodeviation at distance fixation immediately after adjustment was 8.1 ± 5.4 PD in the LR-Adj group and 8.4 ± 4.7 PD in the MR-Adj group (P = 0.843). Postoperative exodrift occurred in both groups, and amount of exodeviation after 1.5 year were not significantly different. For the comparison of the amount of exodrift at near measurement, the amount of exodrift within 1 month after surgery was smaller in the MR-Adj group than that in the LR-Adj group (P = 0.01). Surgical success rates were 81.0% in the LR-Adj group and 84.2% in the MR-Adj group (P = 0.559). CONCLUSIONS: The smaller amount of exodrift in the MR-Adj group may mean that the positional stability of the resected muscle is favorable in the early post-adjustment period. However, there was no significant difference groups in the final exodeviation and surgical success rate between the groups. Resected muscle adjustment was as effective as the conventional recessed muscle adjustment.

The effect of platelet-rich fibrin on wound healing following strabismus surgery.

PURPOSE: To investigate the effect of platelet-rich fibrin (PRF) on post-operative wound healing following strabismus surgery in a rabbit model. METHODS: Nine New Zealand white rabbits were involved in the study. One of these nine rabbits was kept in control without having any operation. Both eyes of eight rabbits underwent superior rectus muscle (SRM) resection. After resection of SRM, PRF was applied to SRM of the right eyes. In the left eye, SRM was not wrapped with PRF and served as a control. The rabbits were sacrificed and enucleated 6 weeks after the surgery. Inflammation and vascular proliferation were assessed by staining with haematoxylin-eosin. Scar and fibrosis were examined by the Masson trichrome staining. Immunohistochemical staining was performed for a vascular endothelial growth factor (VEGF) and alpha-smooth muscle actin (α-SMA). RESULTS: There was no significant difference in terms of inflammation (p = 0.535), vascularization (p = 0.602), and fibrosis (p = 0.745) between the eyes. Immunohistochemical staining for VEGF demonstrated no significant difference (p = 0.745). However, significant staining for α-SMA was detected in PRF-treated eyes compared with control eyes (p = 0.037). CONCLUSION: Consistent with the hypothesis that PRF facilitates wound healing as a biocatalyst, there was only a significant difference for α-SMA related to myofibroblast activity which is important for wound remodelling. Future comprehensive studies are needed to extend these results.

Supernumerary Extraocular Muscle: A Rare Cause of Atypical Restrictive Strabismus.

Background and objectives: Supernumerary extraocular muscle (SEOM) is extremely rare. The purpose of this paper was to review the clinical characteristics and surgical outcomes of SEOM patients with atypical restrictive strabismus. Materials and Methods: A retrospective review was conducted on the data from 12 SEOM cases. Pre- and post-operative measurements consisted of visual acuity, cycloplegic refraction, ocular alignment, ocular motility, binocular vision, and imaging. Management strategies included either conservative or surgical treatments. Results: Of the 12 cases reviewed (seven females, five males), the mean ± SD age was 14.3 ± 10.6 years (range: 4-38 years). The right eye was affected in six cases, the left in five, and both eyes in one case. The major clinical manifestations included restrictive ocular motility (12 cases), with seven cases in no less than three directions; varying degrees of horizontal or vertical strabismus; ipsilateral amblyopia (10 cases); and unequal palpebral aperture (10 cases). Imaging results revealed muscular bands originating from the annulus of Zinn and insertion into the globe or other recti, as well as anomalous muscular bands connecting two or more recti, sometimes with optic nerve involvement. Three patients received conservative treatment, while rectus recession with or without resection (seven patients) or rectus disinsertion plus globe fixation (two patients) were performed in those receiving surgical treatments. A surgical success was achieved in four cases. Conclusions: For restrictive strabismus, imaging plays an important role in the diagnosis of SEOM. When the SEOM is difficult to resect, a personalized surgical strategy may be required to achieve a good ocular alignment.

Prism adaptation test before strabismus surgery in patients with decompensated esophoria and decompensated microesotropia.

PURPOSE: To evaluate the effect of Prism adaptation test (PAT) on the angle of squint in decompensated esophoria (decEPH) and decompensated microesotropia (decMET). METHODS: In this single-center retrospective study we reviewed the medical records of patients with the diagnosis of decEPH or decMET, aged at least 12 years, who were treated by strabismus surgery for the first time. The maximum Angle of squint (AOS) for far (F) and near (N) fixation and PAT results before surgery, as well as AOS (F) and AOS (N) after surgery and results of binocular function tests were considered. PAT included wearing a prism based on the largest angle for over 60 min. RESULTS: 100 patients (mean age 37 ± 17 years) were included in the decEPH group, 82 patients (mean age 30 ± 13 years) in the decMET group. For decEPH, before surgery AOS was 25.5 ± 8.8 pdpt (F) and 23.5 ± 9.8 pdpt (N). During PAT the AOS increased significantly by 2.7 ± 4.3 to 28.2 ± 8.6 pdpt (F) and by 4.9 ± 4.5 to 28.3 ± 9.5 pdpt (N). Altogether, in 82% of decEPH patients AOS (F) and/ or AOS (N) in- or decreased by at least 3 pdpt. For decMET, before surgery AOS was 28.6 ± 10.8 pdpt for far (F) and 30.9 ± 11.8 pdpt for near fixation (N). During PAT the AOS increased significantly by 4.2 ± 5.8 to 32.5 ± 9.5 pdpt (F) and by 3.7 ± 6.1 to 34.4 ± 9.5 pdpt (N). Altogether, in 51% of decMET patients, AOS (F) and/ or AOS (N) increased by at least 10 pdpt, therefore more than 5° which would have been maximally expected from mictrotropia, or decreased by at least 3 pdpt. CONCLUSIONS: The Prism adaptation test (PAT) showed remarkable changes in AOS in both decEPH and decMET. In patients with decEPH, the preoperative assessment of the "true AOS" under PAT reflects a pivotal requirement for successful strabismus surgery, as 82% had dose relevant angle changes ≥ 3 pdpt. For patients with decMET the preoperative prism adaptation test is especially of diagnostic value, but also 51% of decMET patients had changes in AOS beyond the expected microtropic angle (≥ 10 pdpt) or even a dose relevant angle decrease (≥ 3pdpt).

Isolated inferior oblique pareses.

PURPOSE: To describe etiology, clinical characteristics, radiological features and management of isolated inferior oblique pareses. METHODS: A diagnosis of inferior oblique paresis was made after a thorough strabismus examination and neuroimaging. The patients were managed surgically with adjustable strabismus surgery, or conservatively. Surgical success was defined as average horizontal deviation within ≤ 10 prism diopters [PD] post-operatively and for vertical deviation, it was ≤ 5 PD, at last follow-up. RESULTS: Seven cases were congenital, 6 cases were bilateral, with esotropia in 6 cases; 'A' pattern in 7 cases and hypotropia in 3 cases. The mean preoperative horizontal deviation was 52.5 PD, and the mean postoperative horizontal deviation was 2.37 PD (p = 0.028). The pre-operative vertical deviation was 18 PD and post-operative vertical deviation was 5 PD. MRI showed reduced IO muscle size; average area being 11.27 mm2 in the affected eyes, with normal sized inferior recti (average: 24.63 mm2) and medial recti muscles (average: 30.08 mm2). Surgical success was seen in all six cases. Average follow-up was 265 days. The Parks' three step test was not valid, except for one acquired unilateral case. CONCLUSION: Isolated pareses of inferior oblique muscle exhibit defective elevation in adduction of the affected eye, 'A' pattern and fundus intorsion, and is confirmed by neuroimaging. These can be successfully managed surgically to correct the deviation.

Tendon elongation with bovine pericardium in strabismus surgery-indications beyond Graves' orbitopathy.

BACKGROUND: For some patients with complex ocular motility disorders, conventional strabismus surgery is insufficient. Surgery with tendon elongation allows correction of larger angles and maintains a sufficient arc of contact for rectus muscles. This study reports results for tendon elongation with bovine pericardium (Tutopatch®) in indications other than Graves' orbitopathy in which it is already widely used. METHODS: We reviewed the records of all patients who underwent surgery with Tutopatch® in our institution. Angles of squint and head postures were analyzed preoperatively, on the first postoperative day, and in the long term (median 9 weeks after the operation). Patients with Graves' orbitopathy were excluded. RESULTS: From 2011 to 2018, the procedures on 58 eyes of 54 patients (35 females, median age 35 years (3-75)) met the inclusion criteria. Horizontal rectus muscle surgery (53 eyes) was conducted on patients with residual strabismus (13), Duane's retraction syndrome with eso- (type I: 16)/exodeviation (type II: 2, type III: 1), 6th (7)/3rd nerve palsy (7), Möbius syndrome (2), congenital fibrosis of the extraocular muscles type 3A (CFEOM3A, TUBB3 mutation) (4), and orbital apex syndrome (1). Vertical rectus muscle surgery (5 eyes) was conducted on patients with myasthenia (1), vertical tropia after orbital floor fracture (1), CFEOM1 (2), and Parry-Romberg syndrome (1). 42 eyes had prior eye muscle surgery (1-5 procedures, median 1). Out of 45 patients with postoperative long-term data, 43 showed an angle reduction. Fifty-one percent had an angle of 10Δ (prism diopter) or less, one had a significant over-effect, and 10 had revision surgery. For the heterogeneous group of residual eso- and exotropias, the median absolute horizontal angle was reduced from 35Δ (16 to 45Δ) to 9Δ (0 to 40Δ), for Duane's retraction syndrome from 27.5Δ (9 to 40Δ) to 7Δ (0 to 40Δ), and for sixth and third nerve palsies from 43Δ (20 to 75Δ) to 18Δ (4 to 40Δ). For 3 patients with vertical rectus muscle surgery, the median absolute vertical angle was reduced from 30Δ (20 to 45Δ) to 4Δ (1 to 22Δ). The motility range was shifted in the direction contrary to the elongated muscle in all subgroups. A considerable reduction of the excursion into the field of action of the elongated muscle had to be registered. CONCLUSIONS: Strabismus surgery with bovine pericardium introduces new surgical options for complicated revisions and for rare and complex oculomotor dysfunctions. Yet, it has to be recognized that this type of surgery aiming at maximum effects, despite preservation or restitution of the arc of contact, leads to reduction of the excursion into the field of action of the elongated muscle. Furthermore, dose finding can be difficult depending on the underlying pathology and more than one intervention might be necessary for optimal results.

Effect of the base-out recovery point as the surgical target for acute acquired comitant esotropia.

PURPOSE: To evaluate the treatment efficacy of the preoperative base-out recovery point as the surgical target angle for acute acquired comitant esotropia. METHODS: Prospective study. Twenty-two patients with acute acquired comitant esotropia (AACE) underwent strabismus surgery based on the target angle of the preoperative base-out recovery point. The postoperative deviation, positive fusional vergence, and negative fusional vergence were evaluated and compared with those of 23 normal individuals. RESULTS: The mean follow-up period was 18.68 ± 19.48 months. At the last follow-up, 19 (86.4%) of 22 subjects had orthophoria, whereas 3 (13.6%) had minimal esophoria. The postoperative angle of deviation was significantly smaller than the preoperative angle of deviation at near (P < 0.001) and distance (P < 0.001). Postoperative sensory fusion was significantly better than preoperative fusion at near (P < 0.001) and distance (P < 0.001). The postoperative stereoacuity improved significantly after the surgery at near (P < 0.001) and distance (P < 0.001). Compared with the controls, the convergence and divergence amplitudes in the AACE patients were similar at distance (P > 0.05) but were still narrower at near (P < 0.001). CONCLUSION: Good alignment and binocular balance were obtained with the surgical target angle of the base-out recovery point in AACE.