Variation between surgeons in rate of reoperation after horizontal strabismus surgery among Medicare beneficiaries: associations with patient and surgeon characteristics and adjustable sutures.

Objective: To quantify variation between surgeons in reoperation rates after horizontal strabismus surgery, and to explore associations of reoperation rate with surgical techniques, patient characteristics, and practice type and volume. Methods: Fee-for-service payments in a national database to providers for Medicare beneficiaries having strabismus surgery on horizontal muscles between 2012 and 2020 were analyzed retrospectively to identify same calendar year reoperations. Multivariable linear regression was used to determine predictors of each surgeon's reoperation rate. Results: The reoperation rate for 1-horizontal muscle surgery varied between 0.0% and 30.8% among 141 surgeons. Just 7.8% of surgeons contributed over half of the reoperation events for 1-horizontal muscle surgery, due to the presence of high-volume surgeons with high reoperation rates. Surgeon seniority, gender, surgery volume, and use of adjustable sutures were not independently associated with surgeon reoperation rate. We explored associations of reoperation with patient characteristics, such as age and poverty. Surgeons in the South tended to have a higher reoperation rate (p=0.03) in a multivariable model. However, the multivariable model could only explain 16.3% of the inter-surgeon variation in reoperation rate for 1-horizontal muscle surgery. Discussion: Strabismus surgery is similar to other areas of medicine, in which large variations in outcomes between surgeons are observed. Future work can be directed towards explaining this variation. Conclusions: Patient-level analyses that fail to consider variation between surgeons will be dominated by a small number of high-reoperation, high-volume surgeons. Order-of-magnitude variations exist in reoperation rates among strabismus surgeons, the cause of which is largely unexplained.

Long-term surgical outcome and impact on daily life activities of strabismus surgery in thyroid-associated ophthalmopathy with and without previous orbital decompression.

BACKGROUNDS: To report the long-term surgical outcomes and the impact on daily life activities of strabismus surgery in patients with Thyroid Associated Orbitopathy (TAO) with and without previous orbital decompression. METHODS: Patients who underwent strabismus surgery for TAO were retrospectively reviewed. The primary outcome was to evaluate the influence of orbital decompression on the outcomes of TAO related strabismus surgery. Surgical success was defined by the resolution of diplopia and a post-operative deviation < 10 prism diopters (PD). The secondary outcomes were the clinical features, surgical approaches, and impact on daily life activities. RESULTS: A total of 45 patients were included in the study. The decompression surgery group (DS) included 21 patients (46.7%), whereas the non-decompression surgery group (NDS) patients were 24 (53.3%). The mean follow-up time from the last strabismus surgery was 2,8 years (range 8-200 months). Successful surgical outcome was achieved in 57,1% of patients in the DS, and 75% of patients in the NDS (p = 0,226). DS patients required almost twice the number of surgical interventions for strabismus compared to the NDS (1,95 vs. 1,16 respectively, p = 0,006), a higher number of extraocular muscles recessed in the first surgery (2,67 vs. 1,08 respectively, p < 0.001), and a lower rate of unidirectional surgery compared to NDS (23% vs. 95%, p < 0,001). At the pre-operative assessment, 71.4% of DS patients had eso-hypotropia, while no patients had this type of strabismus in the NDS group (p < 0.001). On the other hand, the hypotropia rate was 79.2% in NDS patients and only 4.8% in DS patients (p < 0.001). Moreover, 21,8% of NDS patients used prism lenses in daily life activities, compared to 42.9% of patients that used prism lenses to reduce the impairment in their daily life activities (p = 0.016). CONCLUSIONS: The results of our study showed that DS patients required almost twice the number of strabismus surgical procedures, a higher number of extraocular muscles recessed in the first surgery, and an increased need for prism lenses to correct the residual deviation compared to the NDS, but with similar long-term surgical outcomes.

Surgery for longer duration supranuclear ophthalmoplegia secondary to brain stem cavernoma: A case report and literature review.

BACKGROUND: Previous reports revealed that patients with acquired paralytic strabismus caused by central nervous system diseases are primarily affected by the etiology and treatment of the condition. Strabismus correction for these acquired paralytic strabismus should be performed as soon as the primary disease has been stabilized for 6 months in order to archive a favorable surgical outcome. CASE: We followed an infrequent case of longer-lasting supranuclear ophthalmoplegia secondary to brain stem cavernoma. OBSERVATION: A 25-year-old Chinese Han female developed aberrant head posture and ipsilateral conjugate gaze palsies 8 years after the first brainstem hemorrhage caused by pontine cavernoma. The patient was diagnosed with supranuclear ophthalmic palsy and brain stem cavernoma after surgery. A resection-recession procedure along with a rectus muscle transposition was performed. The patient's abnormal head position disappeared, with a normal primary position. CONCLUSION: Resection-recession procedures combined with rectus muscle transposition works very well for longer duration large-angle strabismus caused by brain stem cavernoma.

Strabismus management in retinoblastoma survivors.

PURPOSE: To report the result of strabismus surgery in eye-salvaged retinoblastoma (Rb) patients. METHODS: A retrospective case series including 18 patients with Rb and strabismus who underwent strabismus surgery after completing tumor treatment by a single pediatric ophthalmologist. RESULTS: A total of 18 patients (10 females and 8 males) were included with a mean age of 13.3 ± 3.0 (range, 2-39) months at the time tumor presentation and 6.0 ± 1.5 (range, 4-9) years at the time of strabismus surgery. Ten (56%) patients had unilateral and 8(44%) had bilateral involvement and the most common worse eye tumor's group was D (n = 11), C (n = 4), B (n = 2) and E (n = 1). Macula was involved by the tumors in 12 (67%) patients. The tumors were managed by intravenous chemotherapy (n = 8, 47%), intra-arterial chemotherapy (n = 7, 41%) and both (n = 3, 17%). After complete treatment, the average time to strabismus surgery was 29.9 ± 20.5 (range, 12-84) months. Except for one, visual acuity was equal or less than 1.0 logMAR (≤ 20/200) in the affected eye. Seven (39%) patients had exotropia, 11(61%) had esotropia (P = 0.346) and vertical deviation was found in 8 (48%) cases. The angle of deviation was 42.0 ± 10.4 (range, 30-60) prism diopter (PD) for esotropic and 35.7 ± 7.9 (range, 25-50) PD for exotropic patients (P = 0.32) that after surgery significantly decreased to 8.5 ± 5.3 PD in esotropic cases and 5.9 ± 6.7 PD in exotropic cases (P < 0.001). The mean follow-up after surgery was 15.2 ± 2.0 (range, 10-24) months, in which, 3 (17%) patients needed a second surgery. CONCLUSION: Strabismus surgery in treated Rb is safe and results of the surgeries are acceptable and close to the general population. There was not associated with tumor recurrence or metastasis.

A Case of Superior Oblique Palsy without Brown Syndrome Induced by a Dog Bite.

BACKGROUND Pseudo-Brown syndrome is characterized by dysfunction of the superior oblique tendon-trochlear complex. Canine tooth syndrome, which involves superior oblique palsy with pseudo-Brown syndrome, results from damage to the trochlear and superior oblique tendon from dog bites around the eye. This report describes a variant of canine tooth syndrome without pseudo-Brown syndrome following a dog bite around the left upper eyelid. In this case, magnetic resonance imaging (MRI) facilitated early diagnosis and therapeutic intervention. CASE REPORT A 19-year-old man presented with torsional diplopia following a dog bite around the left upper eyelid and forehead. Five days after the injury, an alternate prism cover test revealed 6 prism diopters (Δ) exotropia and 5Δ left hypertropia. Ocular motility showed no significant limitation in elevation or depression during adduction. MRI performed on the same day showed a high-signal area extending from the superior oblique tendon to the trochlear region and the superior oblique muscle belly of the left eye. A diagnosis of canine tooth syndrome without pseudo-Brown syndrome was made and oral steroids were administered. Ocular alignment did not improve, so left inferior oblique myotomy was performed 7 months after the injury. The patient's cyclovertical diplopia resolved postoperatively. CONCLUSIONS Dog bites around the eye can result in abnormalities of the extraocular muscles. Early MRI may be useful for diagnosis and determining treatment strategies. This report has highlighted the importance of rapid assessment and management of patients with dog bites involving the eye.

[Clinical effect of superior oblique re-tucking for recurrent or residual compensatory head position].

Objective: To evaluate the effects of re-tucking the superior oblique muscle on recurrent or residual compensatory head position. Methods: A retrospective case series study was conducted. 12 recurrent or residual compensatory head position patients (12 eyes) with congenital superior oblique palsy who underwent superior oblique re-tucking in Tianjin Eye Hospital from March 2015 to February 2021 were included. All patients had a history of superior oblique tucking procedure and showed signs of superior oblique muscle palsy without inferior oblique muscle overaction. During surgery, the Guyton forced duction test is used to evaluate the relaxation of the superior oblique muscle tendon, which affects the re-tucking length of the muscle.Their head position, vertical deviation, eye movement, fovea-disa angle, and Bielschowsky head tilt test were assessed pre-and post-surgery. Statistical analysis was performed using ttest and paired samples Wilcoxon signed rank test. Results: Out of the 12 patients, 8 were male and 4 were female, aged between 2 and 9 years. The initial surgery was done at age 6, with a superior oblique recession length of (7.17±1.03) mm. Recurrent head tilt occurred in 11 patients after (3.82±0.98) months postoperatively, and 1 patient had residual head tilt, with a followup period of six months or more. Ocular motility examination revealed underaction of the superior oblique muscle, positive Bielschowsky's head tilt test, and Guyton forced duction tese indicating relaxation of the paralyzed superior oblique muscle tendon. Scar adhesion was observed at the stop of the superior oblique muscle, as well as the previous sutures. The scar and the sutures around the stop of the superior oblique muscle were released, the mean re-tucking amount was(7.83±1.59)mm. Follow-up at 12 to 18 months postoperatively showed disappearance of compensatory head position, significant improvement in superior oblique muscle lag, normal ocular motility, and no occurrence of Brown syndrome. The results of Bielschowsky head tilt were negative in 9 cases and still positive in 3 cases after superior oblique re-tucking. The primary vertical deviation was 2.5 (2.0, 5.3) prism diopter pre-operatively and 1 (0, 1) prism diopter post-operatively, respectively. The difference was statistically significant (U=6.00, P<0.001). The total amount of FDA in both eyes was (-22.04±5.47)° and (-15.27±6.08)° pre-and post-operatively, respectively. The difference was statistically significant (t=2.87, P=0.009). All 12 patients have normal eye movement after superior oblique re-tucking procedure. All patients had no compensatory head position at last follow-up. Conclusions: Superior oblique re-tucking is suitable for patients with relaxation of the superior oblique muscle tendon and extrocular rotation as the main sign. It can effectively and safely correct the recurrent or residual compensatory head position after re-tucking the superior oblique muscle.

Effect of vertical central plication on vertical deviations.

PURPOSE: To evaluate the surgical effect of the Wright central plication on vertical rectus muscles to correct vertical strabismus. METHODS: In this multicenter, retrospective, observational outcomes study, data were collected from two surgeons in different practice settings (2017-22). All patients who underwent vertical rectus central plication were included; those undergoing any concurrent strabismus surgery for vertical strabismus were excluded. Primary outcome was amount of strabismus correction in prism diopters per vertical rectus central plication. Secondary outcome was to determine factors associated with better or worse surgical outcomes and patient and patient responses. Data were analyzed using descriptive and bivariate statistics. RESULTS: A total of 36 patients were included. Mean age was 60 years. Mean follow-up was 8.4 months. Of the 36 patients, 11 (31%) had idiopathic strabismus, and 7 (19%) had congenital superior oblique palsy. The remainder had a history that included prior ocular surgery, trauma, and Brown syndrome; 16 (44 %) had prior strabismus surgery. Of 31 patients with preoperative diplopia, 23 (74%) had postoperative resolution of diplopia, and 10 of 16 patients with preoperative prisms (63%) no longer required prisms postoperatively. Mean vertical deviation change was 4.7Δ. Subgroup analysis removing patients with congenital superior oblique palsy showed a larger response of 5.5Δ. 78% of patients had a final deviation <5Δ. No complications or induced postoperative diplopia was reported. CONCLUSIONS: In our study cohort, vertical rectus central plication corrected approximately 5Δ (range, 4.5Δ-5.5Δ) of vertical strabismus due to a variety of causes.

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.

Changes in ocular extorsion after horizontal muscle surgery in patients with intermittent exotropia coexisting with hypertropia and mild inferior oblique overaction.

PURPOSE: To investigate changes in vertical strabismus and extorsion in patients with intermittent exotropia and mild unilateral inferior oblique muscle overaction (IOOA) who underwent horizontal muscle surgery without vertical or oblique muscle surgery. METHODS: The medical records of 41 patients were retrospectively analyzed. The patients were followed up for at least 6 months after surgery. Fundus photography was performed before and after surgery, and the sum of the angles of torsion in both eyes was used to measure changes in extorsion using ImageJ software. The enrolled patients were divided into two groups according to the degree of IOOA: patients with grade 1 IOOA were placed in +1 IOOA group and those with grade 2 IOOA in +2 IOOA group. The pre- and postoperative angles of horizontal and vertical strabismus and extorsion were compared between the two groups. RESULTS: The +1 IOOA and +2 IOOA groups included 24 and 17 patients, respectively. The angle of preoperative exotropia did not differ significantly: 25.54 ± 5.68 prism diopters (PD) and 25.65 ± 8.11 PD in the +1 IOOA and +2 IOOA groups, respectively. In the +1 IOOA and +2 IOOA groups, hypertropia was 2.67 ± 1.52 PD and 2.82 ± 1.13 PD, respectively, and extorsion angles were 7.14 ± 2.77° and 7.94 ± 2.87°, respectively. As the IOOA degree increased, the extent of hypertropia and extorsion also increased. However, there were no significant differences between the two groups. Postoperative angles of hypertropia and extorsion significantly decreased in both groups (p < 0.001) after surgery. The degree of change in hypertropia and extorsion was not significantly different between the two groups (p = 0.563 and p = 0.354, respectively). CONCLUSIONS: Hypertropia and extorsion improved significantly after horizontal muscle surgery in patients with mild unilateral IOOA and intermittent exotropia. There was no significant difference in the improvement in hypertropia or extorsion between IOOA grades I and II.

Surgically Induced Scleritis Associated With Suture Hypersensitivity Following Strabismus Surgery.

A 67-year-old woman with history of mild suture hyper-sensitivity presented with localized scleritis after strabismus surgery. After infection was ruled out, the patient was prescribed topical and systemic non-steroidal anti-inflammatory drugs and systemic steroids, which led to full clinical resolution. [J Pediatr Ophthalmol Strabismus. 2024;61(1):e4-e6.].

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.

Cauterization-mediated restriction from penetrating orbital trauma.

A healthy 32-year-old woman presented with binocular diplopia immediately after sustaining a penetrating injury to the left periocular adnexa with a hot metal skewer. Examination revealed an incomitant esotropia, with complete limitation of abduction of the left eye with downshoot in left gaze and normal afferent visual function. Computed tomography and magnetic resonance imaging demonstrated no fracture, but there was mild thickening of the medial rectus muscle and associated fat stranding. Lack of orbitomuscular tethering or hematoma led to the presumptive diagnosis of thermal cauterization injury causing left medial rectus restriction. Given the lack of literature on this mechanism of injury, the patient was monitored closely. She exhibited remarkable spontaneous improvement in motility over 6 months, with near orthophoria in primary gaze. However, bothersome residual esotropic diplopia in left gaze prompted a left medial rectus recession, with a good outcome. This case demonstrates that isolated extraocular muscle thermal injuries and consequential strabismus can recover spontaneously; longitudinal observation before surgical intervention may be appropriate in such cases.

Inferior oblique myectomy for postoperative limitation of elevation in abduction.

Antielevation syndrome is commonly described following anteriorization of the inferior oblique muscle. A similar phenomenon may occur following inferior oblique muscle recession, creating a distinct strabismus pattern in the setting of cranial trochlear nerve palsy. We report 3 adult patients, 69-72 years of age, who presented at the Stanford Byers Eye Institute with a similar strabismus pattern-limited elevation in abduction following previous inferior oblique muscle recession for congenital/long-standing trochlear nerve palsy. All 3 patients had a small hypertropia in primary gaze with ipsilateral inferior oblique overaction, limited elevation in abduction, and inferotemporal conjunctival scars. Two patients had a V-pattern strabismus. Following myectomy of the previously recessed inferior oblique muscle, elevation in abduction improved, and symptoms resolved in all 3 patients.

An unexpected turn: a case of torsional anomalous retinal correspondence after myectomy of previously anteriorized inferior oblique muscles in a child.

We report a case of torsional diplopia caused by presumed torsional anomalous retinal correspondence after myectomy of previously asymmetrically anteriorized inferior oblique muscles for inferior oblique overaction. Given this patient's experience, it may be prudent to operate with caution on previously anteriorized inferior oblique muscles, especially when anteriorization is performed at a very young age.

Postoperative magnetic resonance imaging of the inferior oblique muscle.

No previous imaging study has described the appearance of the inferior oblique muscle after surgery. It is unknown whether findings signifying prior myectomy or recession are recognizable on magnetic resonance (MR) imaging and how they might differ for the two procedures. After myectomy via a temporal approach, the cauterized muscle stump retracts into the medial orbit. How far it retracts and whether it reattaches to the globe remains unclear. To address these issues, orbital MR images were reviewed in 5 patients who had previously undergone inferior oblique myectomy or recession. In each case, the operated muscle exhibited subtle but telltale features, when compared with the normal, fellow inferior oblique. After myectomy, the inferior oblique still terminated lateral to the inferior rectus muscle and appeared closely apposed to the globe, although not necessarily attached to the sclera.

Fundus torsion following inferior oblique muscle weakening.

PURPOSE: To determine the postoperative fundus torsion following surgical inferior oblique (IO) weakening in patients with inferior oblique overaction (IOOA). METHODS: In this interventional case series, 37 patients with IOOA ≥ +1 and reliable preoperative fundus photographs were included. IO weakening was accomplished through myectomy or anterior transposition. Fundus photography was repeated at 3 months' follow-up. The primary outcome was change of disk foveal angle (DFA), measured as the angle between the line connecting the center of the fovea and optic disk and horizontal. Success or normal fundus torsion was defined as a postoperative angle of 0° to 8° of extorsion. Residual extorsion was defined as postoperative extorsion of > 8°. Postoperative intorsion was defined as any amount of induced intorsion. RESULTS: Mean age of patients (56% females) was 6.46 ± 6.79 years. At follow-up at least 3 months after surgery, the mean change of DFA was 7.79 ± 6.24° of reduction of extorsion after IO myectomy (P < 0.001) and 6.05 ± 6.07° after IO anterior transposition (P = 0.005). Normal fundus torsion was achieved in 50% of patients after myectomy and 36.4% of patients after anterior transposition. Residual extorsion was observed in 49% of patients; induced intorsion in 5%. CONCLUSIONS: Using objective measurement of fundus photographs, fundus extorsion was decreased in 94.7% of patients after myectomy or anterior transposition.

[Clinical characteristics and surgical outcomes in pediatric progressive restrictive strabismus].

Objective: To investigate the clinical features, imaging manifestations, histopathological characteristics, and surgical outcomes in pediatric progressive restrictive strabismus. Methods: A retrospective case series study was conducted, including data from 9 cases (9 eyes) of pediatric progressive restrictive strabismus treated at Tianjin Eye Hospital from June 2017 to October 2022. The study compared the degree of globe protrusion in both eyes, changes in eyelid fissure height during internal and external rotation in the primary gaze, summarized clinical characteristics, and analyzed intraoperative conditions, surgical outcomes and postoperative histopathological results of strabismus correction surgery. Statistical analysis was performed using Wilcoxon signed-rank test and Friedman two-way analysis of variance. Results: All 9 cases involved unilateral onset, with 4 males and 5 females. Three cases affected the right eye, and six affected the left eye. Onset age ranged from 2 to 40 months. The degree of globe protrusion in the affected eyes was 13.00 (12.00, 13.00) mm for the right eye and 12.00 (12.00, 13.50) mm for the left eye, with no statistically significant difference (Z=-1.00, P=0.317). There were no significant changes in eyelid fissure height during internal rotation [8.00 (7.25, 8.00) mm], primary gaze [7.50 (7.00, 8.00) mm], and external rotation [8.00 (7.75, 8.00) mm] in the affected eyes (χ²=1.00, P=0.607). No apparent abnormalities were observed in head CT or MRI scans, serum, or immunological tests. However, orbital CT or MRI scans indicated thickening of different extraocular muscle bellies. Six out of nine cases underwent strabismus correction surgery, and postoperative examination revealed restriction in eye movement despite achieving orthophoria in the primary gaze. Tissue pathology of three cases showed increased collagen fiber proliferation in one, scattered bundles of smooth muscle fibers amid diffuse collagen fiber proliferation in another, and abnormal proliferation of striated muscle fibers with varying diameters, increased paired box (PAX)7-positive satellite cells expressing slow muscle myosin in the third case. Conclusions: Pediatric progressive restrictive strabismus presents with restrictive changes, without significant alterations in globe protrusion and eyelid fissure height. Imaging examinations reveal thickening of the extraocular muscle bellies in the affected eye. Although strabismus correction surgery improves eye position, postoperative eye movement remains restricted. Histopathological findings in some cases show abnormal proliferation of skeletal muscle fibers or collagen fibers.

Refractive Changes After Horizontal Strabismus Surgery.

PURPOSE: To investigate the changes in refractive status after surgery in patients with horizontal strabismus and high refractive error. METHODS: This was a prospective study of patients with horizontal strabismus and high refractive error. The patients were divided into a horizontal rectus recession group (group 1) and a horizontal rectus recession combined with horizontal rectus resection group (group 2). The postoperative follow-up duration was 3 months. The refractive status of the patients was evaluated at each postoperative examination, and the refractive changes in the two groups were compared. RESULTS: The spherical equivalent in group 1 changed by -0.26 D at 3 months postoperatively relative to the preoperative value (p = 0.078), indicating gradual progression toward myopia over time, but the difference was not significant; however, the postoperative cylinder in group 1 significantly increased by 0.34 D at 3 months postoperatively relative to the preoperative value (p = 0.03). The spherical equivalent in group 2 also indicated progression toward myopia; compared with the preoperative value, the spherical equivalent significantly decreased by -0.28 D (p = 0.019) at 1 month postoperatively and decreased by -0.21 D at 3 months postoperatively. The regression line drawn among the points also indicated a progression in the spherical equivalent toward myopia. In group 2, the cylinder increased by 0.30 D (p = 0.004) from the preoperative level at 1 month postoperatively, peaked, then decreased by 3 months postoperatively. CONCLUSIONS: Patients with high refractive error who undergo horizontal strabismus correction will experience myopic shift. Patients who undergo rectus recession surgery should be fully informed of the possibility of changes in astigmatism preoperatively. For patients who undergo horizontal rectus recession combined with horizontal rectus resection, it is not recommended that glasses be changed within 1 month after surgery.