Long-term surgical outcomes of one-muscle vs. two-muscle horizontal strabismus surgery.

PURPOSE: While horizontal strabismus surgery is generally considered to have favorable outcomes, success rates can vary by type of procedure. Our purpose is to compare the long-term outcomes of patients who underwent one-muscle vs. two-muscle horizontal strabismus surgery. METHODS: This is a retrospective study comparing one-muscle to two-muscle strabismus surgery for small to moderate angle horizontal strabismus. Demographic data and eye exam parameters were compared at baseline and postoperatively (6 months up to 6 years). Surgical success was defined as a post-operative angle of 10 PD or less. We also compared outcomes by strabismus type: esotropia vs exotropia and adjusted the analysis for previous strabismus surgery. RESULTS: Out of 89 patients with moderate angle horizontal strabismus (25 PD or less), 17 patients had a one-muscle operation, and 72 patients had two-muscle surgery. The mean age was 14.12 ± 9.30 years and 11.70 ± 11.30 years for the one-muscle and two-muscle groups, respectively (p = .74). The baseline characteristics of both groups were comparable. Follow-up time was 32.82 ± 26.93 months in one-muscle and 37.67 ± 23.81 in two-muscle groups (p = .29). Success rate was 70.6% for the one-muscle group and 68.10% for the two-muscle group (p = .69). Outcomes were similar when divided into esotropia and exotropia. The success rate was not affected by previous strabismus surgeries nor by the initial angle of deviation. CONCLUSION: One-muscle and two-muscle horizontal strabismus surgery had similar long-term outcomes and did not differ by strabismus type nor by angle of deviation.

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.

Botulinum toxin augmented surgery versus conventional surgery in the management of large-angle concomitant esotropia: A randomized clinical trial.

BACKGROUND: The surgical management of large-angle concomitant esotropia is challenging with high reoperation rates. This study aims to assess the effectiveness and safety of intraoperative botulinum toxin A (BTA) augmentation compared to surgery alone in large angle concomitant esotropia. MATERIALS AND METHODS: This is a prospective randomized interventional study. Patients with large angle concomitant esotropia (≥55 prism diopter [PD]) were randomly allocated to either surgery only (Group I) or BTA augmented surgery (Group II). The surgical effect in PD/mm was calculated and compared between the study groups at all follow up intervals. Treatment was considered successful if the patients had orthotropia ± 10 PD at their final examinations. RESULTS: A total of 23 patients were included in the study, 11 in Group I and 12 in group II. The surgical effect was significantly greater in Group II compared to Group I at all follow up durations. The 1-year surgical effect was 32.5% greater in Group II compared to Group I (5.99 ± 0.69 vs. 4.52 ± 0.91 PD/mm, respectively, P = 0.001). The success rate was greater for Group II compared to Group I (75% vs. 63.64%, respectively), but this difference was not statistically significant (P = 0.901). CONCLUSION: Botulinum toxin augmented surgery is a good alternative to surgery alone in the treatment of large angle concomitant esotropia. BTA injection exerts a significant augmentation effect on medial rectus muscle recessions.

An atypical case of bilateral optic neuritis after strabismus surgery under general anesthesia.

INTRODUCTION: Strabismus surgery under general anesthesia is a common procedure with rare complications in the form of hemorrhage, infection, slipped muscle, lost muscle, scleral perforation, and anterior segment ischemia. We report a unique case of bilateral optic neuritis following squint surgery under general anesthesia in a 15-year-old girl. METHODS: A 15-year-old girl presented with accommodative esotropia with V pattern. She underwent uneventful bilateral inferior oblique recession surgery under general anesthesia with Propofol 60 mg, Atracurium 30 mg, and Fentanyl 70 mcg. On the first post-operative day, the patient had an acute onset of temporal headache which was non-radiating. She responded to supportive treatment and was discharged. However, on the 7th postoperative day, she presented with a constant severe headache in the bitemporal region (left > right) for 3 days. She also experienced a painless diminution of vision for 2 days. There was no vomiting, fever, loose stools, diplopia, difficulty in breathing, peripheral sensation loss, generalized weakness, or bowel/bladder incontinence. RESULTS: The best corrected visual acuity was 6/9 in right eye, and 6/9p in left eye with a relative afferent pupillary defect (RAPD) in the left eye. Both optic discs appeared hyperemic with blurred margins. Magnetic resonance imaging (MRI) of the brain and orbit showed hyperintensity along the intraorbital and intracanalicular parts of bilateral optic nerves on T2 weighted image suggesting bilateral optic neuritis. She received intravenous methylprednisolone pulse therapy followed by oral steroids and responded to the medical treatment with improvement in vision but developed steroid-induced glaucoma requiring medical management over several weeks. DISCUSSION: Neuro-ophthalmic complication in the form of non-arteritic ischemic optic neuropathy has been reported after various ophthalmic surgeries, but bilateral optic neuritis has not been reported to date. This possibility should be kept in mind if any patient presents with similar symptoms. This report also highlights IOP monitoring in pediatric patients receiving systemic steroids to prevent loss of vision due to steroid-induced glaucoma.

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.

Surgical management of oculomotor nerve palsy - a review of the literature.

We aim to review the surgical management techniques available for patients with oculomotor nerve (OMN) palsy, compare and contrast the approaches and subsequent outcomes. A search of the literature was carried out to yield all papers relevant to the topic, and a wide spectrum of surgical techniques were identified. These included: muscle shortening and lengthening procedures, muscle transposition, globe fixation and ptosis surgery. Patients often require a synergistic combination of these techniques. Strabismus surgery for OMN palsy can be approached through a variety of different techniques to improve the quality of life, independence and aesthetics for the patient.

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.

Combined recession and resection of the same lateral Rectus in the treatment of exotropia.

BACKGROUND: Besides rest position abnormalities, exotropia could also be due to hypertonia of the Lateral Recti (LR) given divergence frequently decreases under general anesthesia (GA). Combined Recession-Resection of the Same Muscle (RRSM) is a promising alternative to the Faden procedure in the surgical treatment of overacting MR in esotropia. We thus examined here the effectiveness of combined RRSM of the LR for the treatment of exotropia that decrease under GA. METHODS: We performed a retrospective, single-center evaluation over a 16-month period of 100 patients operated on for exotropia that decreased under deep GA (91% of 110 consecutive operated cases). We excluded re-operations and pure convergence insufficiencies. We performed a combined RRSM of one or two LR. It included a 10mm-recession and a "fine-tuned" resection of LR based on Quantitative Forced Duction Test scores. MR resection was combined when exotropia exceeded 35PD or for unilateral surgery. We report on patient outcomes 6 months after surgery. RESULTS: Successful results were obtained (-8-+8 PD measured on Alternate Cover Test) among 83% of cases at distance fixation and 91% at near fixation after 6 months. The Newcastle Control Score also improved from 5.8 to 1.7 after 6 months. No surgery-related complications or repeat surgeries were reported. CONCLUSIONS: In our experience a majority of exotropias decrease under GA and our strategy of combined RRSM of the LR is effective for the treatment of such exotropias. Long-term follow-up of the cohort is required to investigate the stability of these outcomes, and confirmation of our results by other works.

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.

Retrobulbar hemorrhage during strabismus surgery.

Purpose: This case report presents an event of retrobulbar hemorrhage (RH) occurring during the initial stage of strabismus surgery after incision of the conjunctiva and Tenon's capsule. Observation: Significant bleeding with subsequent proptosis was observed intraoperatively after the incision of conjunctiva and Tenon's capsule during routine strabismus surgery on the medial rectus muscle in a 5-year-old boy. Intravenous mannitol was administered intraoperatively and surgery was completed as planned. The RH receded within 24 hours without the necessity of orbital decompression. Tenon's capsule prolapse was noted on the first postoperative day and managed with surgical excision under shallow intravenous anesthesia. No damage to the optic nerve or ganglion cells was detected a week after and three months post-surgery. Conclusions and importance: Strabismus surgery bears a risk of RH at every stage of the operation. Careful hemostasis should be provided at each step of the procedure to decrease the risk of such an event. Patients after events of serious intraoperative bleeding should undergo careful post-operative investigation towards coagulation insufficiencies, though no such deficits were identified in the present case.

Phased strabismus surgery under topical anesthesia.

PURPOSE: To evaluate the feasibility and outcomes of phased strabismus surgery under topical anesthesia, with intraoperative comparison of ocular alignment in supine and seated positions. METHODS: This retrospective clinical investigation analyzed the data of patients who underwent phased strabismus surgery with fixed sutures under topical anesthesia. The technique consisted of 2 phases, spaced out with an intraoperative alternate prism cover test (performed in supine and seated positions): (1) surgery on one or two muscles, as defined by a preoperative surgical plan; (2) if judged necessary, a further one-muscle surgery. Surgical success was defined as a residual angle of horizontal and vertical deviation ≤±8Δ and ≤5Δ, respectively, and the presence of single binocular vision in primary position in patients with preoperative diplopia. Follow-up visits were scheduled 1 day, 1 month, and 6 months after surgery. RESULTS: The review identified 38 patients (age range: 10-80 years). Surgery was well tolerated by all patients. Twelve (32%) required a second phase. No statistically significant differences were found for intraoperative angles of deviation in supine and seated positions. Surgical success was reached, respectively, in 88% and 87% of cases with horizontal and vertical deviation 6 months after surgery. No patients were reoperated during the follow-up period. CONCLUSIONS: Phased strabismus surgery is a feasible technique for various types of strabismus in adults and children. Secondly, intraoperative evaluation of ocular alignment can be performed either with the patient seated or supine, with the same accuracy in terms of surgical success.

Intraocular pressure changes at different gaze positions after superior rectus muscle-lateral rectus muscle loop myopexy in highly myopic strabismus.

PURPOSE: To evaluate changes in intraocular pressure (IOP) at different gaze positions before and after superior rectus muscle-lateral rectus muscle (SR-LR) loop myopexy in highly myopic strabismus (HMS). STUDY DESIGN: Nonrandomized clinical, prospective, interventional trial. METHODS: Fourteen patients with HMS (18 eyes) who underwent SR-LR loop myopexy were divided into 3 groups: < 100 prism diopters (PD) (mild esotropia [ET] group), > 100 PD (large ET group), and > 100 PD, and simultaneous recession of the medial rectus (MR) muscle was performed (large ET + MR group). Intraocular pressure was measured preoperatively and postoperatively at the primary, abduction, and adduction positions in each group. RESULTS: Intraocular pressure did not change after surgery in the mild ET group. Intraocular pressure significantly decreased in the abduction position (from 20.0 ± 2.1 to 16.0 ± 1.9 mmHg, P = 0.043) in the large ET group and in the abduction (from 22.2 ± 5.9 to 15.6 ± 4.3 mmHg, P = 0.048) and primary positions (from 15.8 ± 5.0 to 10.2 ± 2.8 mmHg, P = 0.043) in the large ET + MR group. The preoperative significant differences in IOP between the abduction and adduction positions in the large ET group (7.4 ± 3.4 mmHg) and the large ET + MR group (10.0 ± 5.5 mmHg) disappeared postoperatively (3.2 ± 2.8 mmHg and 3.6 ± 1.7 mmHg, respectively). The differences in IOP between abduction and adduction were similar in all the groups. CONCLUSION: SR-LR loop myopexy decreased IOP in patients with HMS in the abduction and primary positions.

Incidence, Risk Factors and Management of Postoperative Complications in Horizontal Strabismus Surgery.

OBJECTIVE: To report the incidence, risk factors and management of postoperative complications after horizontal strabismus surgery. DESIGN: Retrospective Cohort study. PARTICIPANTS: The study assessed 1,273 patients with 1,035 cases of exotropia and 238 cases of esotropia, with a minimum 18-month follow-up. METHODS: Retrospective review of strabismus operation patients' medical records included baseline demographics, age at surgery, pre/postoperative visual acuity, and deviation. Complications were categorized as surgical site (infection, scarring, cyst, granuloma, ischemia) and strabismus-related (recurrence, diplopia), with analysis of incidence, risk factors, and management. RESULTS: Among surgical site complications, the incidence of infection, pyogenic granuloma, and anterior segment ischemia were similar between the exotropia (0.3%, 0.3%, 0.2%) and esotropia (0.8%, 0%, 0.4%) groups (p = .221, 0.406, 0.515). In contrast, the esotropia group presented a higher risk of conjunctival inclusion cyst and conjunctival scar than the exotropia group, with incidences of 5.0% vs 2.2% and 6.3% vs 1.3%, respectively (p = .004, <0.001). Regarding strabismus complications, the incidence of early recurrence was not significant between the two groups, with 10.0% in the exotropia group and 10.5% in the esotropia group (p = .553). Older age and poor initial visual acuity were associated with early recurrence (p < .001). The esotropia group had a higher risk of persistent diplopia than the exotropia group, with incidences of 4.2% vs 2.0%, respectively (p = .003). CONCLUSION: Esotropia carries a higher risk of conjunctival inclusion cysts, conjunctival scarring, and persistent diplopia compared to the exotropia group, while both groups exhibit similar rates of early recurrence and other surgical site complications.

Acquired comitant esotropias - comparison of surgical outcomes of accommodative vs non-accommodative types.

Purpose: To compare the motor and sensory outcomes of strabismus surgery and the factors affecting surgical success in acquired acute non-accomodative esotropia (ANAET) and partially accommodative refractive esotropia (pARET). Methods: A retrospective chart review of patients with ANAET and pARET who underwent unilateral or bilateral horizontal rectus muscle surgery between January 2020 and December 2021 was conducted. Patients with postoperative follow-up of at least six weeks were included. Patients with pattern deviation, lateral incomitance, and near-distance disparity were excluded. Motor success was defined as a postoperative deviation within eight prism diopters of orthophoria. Sensory success was defined as presence of binocular single vision (BSV) for both distance and near (Worth four dot test). The effect of factors like age at onset, age at surgery, amblyopia before surgery, duration of squint before treatment, presence or absence and magnitude of vertical deviation, preoperative angle of deviation, and spherical equivalent on the motor and sensory success in each group were analyzed and compared. Results: 38 patients with ANAET and 33 patients with pARET were included. The mean age of onset of esotropia was 8.55 ± 4.65 years and 4.39 ± 2.27 years (p < .001) and the mean age at surgery was 10.62 ± 4.99 years and 7.89 ± 2.84 years (p = .006) in the ANAET and the pARET group respectively. The mean duration of the final follow-up was 38.51 weeks in the ANAET and 48.68 weeks in the pARET group (p = .089). Patients were successfully aligned for both distance and near in 81.5% of patients in the ANAET and 78.9% of patients in the pARET group at the final follow-up (p. 0.775). A BSV for both distance and near at the final follow-up was seen in 81.2% vs 66.6% of patients in the ANAET and the pARET group respectively (p = .25). A good near stereoacuity (<120 arcsecs) was seen in 60.6% and 41.9% of the ANAET and the pARET groups respectively (p = .175). The percentage of patients in the ANAET group who had orthophoria, any esodeviation, and any exodeviation for distance at the final follow-up was 63.1%, 34.2% and, 2.6%. The percentage of patients in the pARET group in similar categories was 36.3%, 42.4% and, 21.2%. None of the demographic and preoperative factors were found to affect the surgical outcomes in the two groups. Conclusions: The motor and sensory outcomes were similar in the two groups. A higher proportion of ANAET patients remained orthophoric during the follow-up. The patients in the pARET group showed a tendency toward exodrift.

Golden Indications and an Overview on the Use of Botulinum Toxin in Strabismus.

Botulinum toxin A (BTXA) is considered a pharmacological agent that may provide an alternative treatment to surgery in strabismus. It can be used as both a diagnostic and therapeutic agent in various concomitant, paralytic, and restrictive disorders. The major advantage of BTXA treatment is that it is non-invasive and does not impact the patient's chance for future surgery in case of an unfavorable response. In some selected disorders, BTXA has become the primary choice of treatment, whereas surgery is found to be more effective in others. Accumulated knowledge and experience have demonstrated that BTXA is more than merely an alternative treatment and has additional specific indications such as in unstable deviations and as an adjunct to surgery. Patients with recurrent deviations despite multiple surgeries are also good candidates for BTXA treatment. Although the major expectation is to obtain a permanent result, BTXA can also be used as a maintenance treatment. This paper mainly focuses on the current indications for the use of BTXA in strabismology, with special emphasis on ideal first-choice applications referred to as "golden indications," within the scope of the author's own experience with the use of BTXA over 30 years.

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.

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

Objective: 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. Methods: 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. Results: 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. Conclusion: 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.

Evaluation of Macular Thickness Changes Following Large Horizontal Rectus Muscle Recession: A Prospective Cohort Study.

Aim The aim of the study was to evaluate the long-term effect of large horizontal rectus muscle recession on macula thickness using spectral domain optical coherence tomography (SD-OCT). Material and methods Forty-two children were included in the study. The intervention groups were the medial rectus (MR) group (=20 eyes ) and the lateral rectus (LR) group (=22 eyes), including the eyes that underwent large medial and lateral rectus muscle recession, respectively. The control group included the fellow 42 unoperated eyes of the same children. Each eye was scanned using Topcon Maestro2 OCT-Angiography (OCTA; Topcon, Tokyo, Japan) preoperatively and then two months following surgery. A paired t-test was used to compare the mean difference in macular thickness between the intervention and control groups using the statistical program R (R Foundation for Statistical Computing, Vienna, Austria). Results The mean change in central, parafoveal, and perifoveal macular thickness of the intervention group was not statistically significant. Conclusion The long-term changes in macular thickness, as evaluated using SD-OCT both for the central and peripheral regions of the fovea, following large horizontal rectus muscle recession surgery, are not statistically significant.

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

INTRODUCTION: In this work, we provide a detailed characterization of a rare complication-subconjunctival cyst formation after strabismus surgery-in a large German cohort. METHODS: 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 1 day, and at 3 months postoperatively. Cysts were analyzed with slit-lamp examination, anterior segment optical coherence tomography (AS-OCT), and histopathological subsumption. RESULTS: 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 20 days 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. CONCLUSIONS: 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.