He ZY, Cui T, Cui ZQ, Yan HX, Chen MX, Luo H. Effects of modified Yokoyama surgery combined with medial rectus muscle recession on esotropia in highly myopia athletes. World J Clin Cases 2025; 13(21): 104918 [DOI: 10.12998/wjcc.v13.i21.104918]
This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Author contributions: He ZY and Luo H contributed to the conception and design of the study, data acquisition and analysis; Cui T, Cui ZQ and Yan HX assisted with data collection; He ZY and Chen MX analyzed the data and wrote the manuscript; Luo H supervised and coordinated the project.
Institutional review board statement: This study was approved by the Ethics Committee of Taiyuan Xinghualing District Central Hospital (No. XY2024012).
Informed consent statement: The data used in this study were not involved in the patients’ privacy information, so the informed consent was waived by the Ethics Committee of Taiyuan Xinghualing District Central Hospital. All patient data obtained, recorded, and managed only used for this study, and all patient information are strictly confidential, without any harm to the patient.
Conflict-of-interest statement: The authors declare that they have no conflict of interest.
Data sharing statement: No additional data are available.
Open Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: https://creativecommons.org/Licenses/by-nc/4.0/
Received: January 10, 2025 Revised: February 25, 2025 Accepted: April 2, 2025 Published online: July 26, 2025 Processing time: 106 Days and 22.6 Hours
Abstract
BACKGROUND
Fixed esotropia in high myopia, characterized by irreversible inward ocular deviation and abduction limitation, presents unique therapeutic challenges for athletes requiring precise binocular coordination. The combination of Yokoyama surgery and medial rectus muscle recession has been proposed as an advanced technique addresses both myopia-induced globe displacement and muscular imbalance offering potential advantages over conventional strabismus surgery in this population.
AIM
To investigate the effects of the modified Yokoyama surgery coupled with medial rectus muscle recession in restoring ocular motility and correcting esotropia among athletes with high myopia and fixed esotropia.
METHODS
A retrospective study analyzed 30 highly myopia athletes (57 eyes) with fixed esotropia treated at our hospital from January 2022 to April 2024. The participants were allocated into two groups based on the surgical method: The traditional group (n = 15, 29 eyes) received conventional strabismus surgery, and the combined group (n = 15, 28 eyes) underwent modified Yokoyama surgery in combination with medial rectus muscle recession. Eye movement improvement, esotropia alleviation, and complications were compared preoperatively and at 1, 3, and 6 months post-treatment.
RESULTS
Both surgical groups exhibited similar baseline scores (traditional: -4.04 ± 0.38 vs combined: -4.12 ± 0.45, P > 0.05), showing severe preoperative limitations in ocular motility. Following the intervention, the combined group achieved significantly better outcomes at both 1 month (combined: -2.25 ± 0.28 vs traditional: -2.67 ± 0.32) and 3 months (combined: -1.48 ± 0.28 vs traditional: -1.76 ± 0.43), with statistically significant improvements (P < 0.05). However, by 6 months, no significant difference was observed between the two groups (combined: -0.93 ± 0.13; traditional: -1.03 ± 0.18; P > 0.05). Prior to treatment, all patients in both groups exhibited a compensatory head posture (CHP). Following treatment, the incidence of CHP decreased to 6.67% in the combined group and 20.00% in the traditional group, both reductions being significant compared to pre-treatment levels (P < 0.05). Nevertheless, the difference in CHP incidence between the two groups after treatment was not significant (P > 0.05). The rates of improvement in esotropia showed an increasing trend in both groups at 1 month (46.43% vs 34.48%), 3 months (78.57% vs 51.728%), and 6 months (100.00% vs 89.66%) post-treatment. Notably, the combined group had a significantly higher improvement rate than the traditional group at the 3-month follow-up (P < 0.05). No significant difference was observed in the esotropia improvement rates between the two groups at 1 and 6 months post-treatment (P > 0.05). The combined group experienced slightly lower but not significant (combined group: 0.00% vs traditional: 3.45%) as opposed to the traditional group (3.45%; P > 0.05).
CONCLUSION
The combination of modified Yokoyama surgery and medial rectus muscle recession provides effective and safe approach to improving in eye movement and esotropia in athletes with high myopia and fixed esotropia, offering reliable clinical benefits.
Core Tip: Fixed esotropia is a prevalent ocular motility disorder in patients with high myopia, this condition proves especially debilitating for athletes, as it disrupts both competitive performance and daily activities. Traditional surgical treatments have often yielded suboptimal results. Recent studies have unraveled that the combination of Yokoyama surgery with medial rectus muscle recession can enhance visual function and quality of life by precisely correcting eye movements and esotropia angles. In this study, we demonstrated that the modified Yokoyama surgery coupled with medial rectus muscle recession can significantly improve ocular motility and esotropia in athletes with high myopia and fixed esotropia, while maintaining a high safety profile. These findings provide scientific evidence and valuable guidance for clinical practice.
Citation: He ZY, Cui T, Cui ZQ, Yan HX, Chen MX, Luo H. Effects of modified Yokoyama surgery combined with medial rectus muscle recession on esotropia in highly myopia athletes. World J Clin Cases 2025; 13(21): 104918
High myopia, a prevalent ophthalmic disease, not only compromises visual acuity but also increases the risks of complications, such as retinal detachment, maculopathy, and fixed esotropia. Fixed esotropia is an ocular misalignment that significantly impairs quality of life and is particularly detrimental for athletes, as it disrupts both competitive performance and daily activities[1-3]. Athletes depend heavily on precise visual coordination and eye movement control. Esotropia can impair their visual alignment and depth perception, thereby hindering athletic performance and increasing injury risks[4,5]. Patients with high myopia complicated with fixed esotropia often experience progressive esotropia, accompanied by hypotropia diplopia characterized by limited abduction and upper vision[6]. Traditional treatments, such as posterior muscle resection surgeries have shown limited efficacy and sometimes even worsening the condition[7]. Therefore, careful surgery is crucial and all the potential errors should be took into consideration. Recent advancements in surgical techniques, including the introduction of modified Yokoyama surgery, have provided novel solutions that are increasingly being used in the clinical management of ophthalmic diseases.
Modified Yokoyama surgery is an innovative approach designed to address abducent nerve palsy and esotropia associated with high myopia. By altering the anchoring points of extraocular muscles, the technique enhances the function of abductor muscles, thereby improving ocular motility. The procedure evolved from Yokoyama and his team’s loop myopexy surgery and has been developed to treat high myopia-associated strabismus[8,9]. The original surgery involved suturing the superior rectus and lateral rectus approximately 15 mm posterior to their insertion points. However, this approach posed technical challenges in patients with deep-set eyes and narrow palpebral fissures. To overcome these limitations, Lee et al[10] modified the loop myopexy surgery by incorporating lateral canthotomy, cantholysis, and upper conjunctival fornix incisions. Medial rectus muscle recession, another widely adopted surgical technique for esotropia correction, involves adjusting the position of the medial rectus muscle to balance the forces of the extraocular muscles, thereby improving ocular alignment with good outcomes[11,12]. When combined with the modified Yokoyama procedure, the two surgical techniques theoretically leverages their respective advantages, not only effectively addressing esotropia but also promoting the recovery of ocular motility.
Nonetheless, there is a lack of systematic research and data support regarding the specific effects of combining these two surgeries on improving eye movement and esotropia. Athletes, as a unique group, have particularly high demands for visual performance due to the intensity and precision required in their sports, that place higher requirements on surgical outcomes. Therefore, it is necessary to validate the effectiveness of this combined surgery through well-designed clinical studies. This study intends to evaluate the effects of modified Yokoyama surgery coupled with medial rectus muscle recession on eye movement and esotropia improvement in highly myopic athletes with fixed esotropia, aiming to provide more scientifically rigorous evidence to guide clinical treatment.
MATERIALS AND METHODS
General data
A retrospective analysis was conducted on clinical data from 30 cases (57 eyes) of highly myopic athletes with fixed esotropia treated at our hospital from January 2022 to April 2024. They were assigned into the traditional group and the combined group based on surgical approach used. The inclusion criteria were as follows: (1) High axial myopia[13]; (2) Diagnosed with fixed esotropia, characterized by inward and downward ocular deviation with conspicuous limitations in outward and upward turning of the eyes[14]; and (3) Meeting technical and physiological requirements for surgery. Exclusion criteria included: (1) Presence of other ocular diseases or surgical history that could affect study results, such as corneal diseases, glaucoma, etc.; (2) Systemic diseases that could affect eye movement or surgical outcomes, such as severe neurological diseases, autoimmune diseases, etc.; and (3) Restrictive strabismus due to other causes such as paralytic strabismus, thyroid-associated ophthalmopathy, orbital inflammatory pseudotumor, and orbital fractures. Baseline data for both groups are displayed in Table 1, with no significant differences (P > 0.05). This study was approved by our medical ethics committee, and all patients provided informed consent.
Table 1 Comparison of baseline data between the two groups, n (%) or mean ± SD.
Items
Combined group (n = 15)
Traditional group (n = 15)
t/χ2
P value
Age (years)
57.15 ± 8.62
57.83 ± 9.14
0.209
0.835
Gender
0.135
0.712
Male
7 (46.67)
6 (60.00)
Female
8 (53.33)
9 (40.00)
History of high myopia (years)
31.68 ± 6.24
32.11 ± 6.78
0.180
0.857
Eye
1.037
0.595
Left
1 (6.67)
0 (0.00)
Right
1 (6.67)
1 (6.67)
Both
13 (86.67)
14 (93.33)
Axial length (mm)
32.79 ± 2.23
32.92 ± 2.12
0.163
0.871
Methods
Both groups underwent surgery performed by the same specialized surgical team. The traditional group was subjected to conventional strabismus surgery using the following protocol: Creating a corneal limbal incision, exposing and isolating the medial rectus; dissecting the intermuscular membrane and retaining ligament, and thoroughly loosening the medial rectus to ensure minimal fascial tissue attachment to the scleral surface; looping sutures around the medial rectus, posteriorly receding it according to the severity of the patient’s strabismus; exposing and isolating the lateral rectus, dissecting the intermuscular membrane and retaining ligament, ensuring minimal fascial tissue attachment to the scleral surface; looping sutures around the lateral rectus muscle, shortening it according to the severity of the patient’s strabismus, and excising any free muscles; interruptedly suturing the bulbar conjunctiva.
In the combined group, modified Yokoyama surgery coupled with medial rectus muscle recession was performed. Anesthesia, either monitored topical anesthesia or general anesthesia, was determined based on the patient's specific condition. Prior to surgery, traction tests were conducted to assess ocular mobility restrictions. A trapezoidal conjunctival incision was made nasally, and the medial rectus was pre-placed with sutures before dissection from the eyeball wall. The temporal conjunctiva was incised trapezoidally, and the retaining ligaments of the superior rectus and lateral rectus were extensively separated. A blunt longitudinal incision was made centrally through the muscle belly, extending posteriorly 12-14 mm to the muscle insertion, exposing the pulley band. Half of the temporal side of the superior rectus and half above the lateral rectus were pre-placed with 6-0 absorbable sutures before dissection from the muscle insertion, with the two muscles crossing over and fixed at each other’s original muscle insertion points. The degree of medial rectus recession was adjusted appropriately during surgery based on the eye position and medial rectus tension (recession degree adjusted according to the patient’s eye position), followed by suturing and fixation to the eyeball wall and bulbar conjunctiva closure.
Observation of indicators
Eye movement improvement were analyzed within the two groups at baseline, 1 month, 3 months, and 6 months post-treatment, using eye movement grading and the presence of compensatory head postures (CHPs; present or absent). Eye movement grade is categorized into 5 levels: -4 to 0, where -4 indicates complete fixation of the eyeball downward and inward, unable to move; -3 suggests slight movement but unable to reach the midline; -2 denotes just reaching the midline; -1 signifies crossing the midline but not fully reaching the desired position; 0 means normal eye movement.
Esotropia correction were assessed through pre- and post-operative orbital computed tomography images at 1 month, 3 months, and 6 months post-treatment within the two groups. Improved esotropia is determined by the change from an inward and downward deviation to a normal position. The improvement rate of esotropia is calculated as (number of cases showing improvement in esotropia/total number of cases) × 100.00%.
Complications were recorded, including bulbar conjunctiva congestion and edema, muscle adhesions, secondary glaucoma, and anterior segment ischemia (ASI).
Statistical analysis
Data analysis were conducted via SPSS 23.0 statistical software. Measurement data were presented as mean ± SD and analyzed using independent t-tests and ANOVA for repeated measurement. Enumeration data were represented as n (%) and analyzed through χ2 tests or rank-sum tests. A P value of less than 0.05 (P < 0.05) was considered statistically significant.
RESULTS
Comparison of eye movement improvement between the two groups
Both surgical groups exhibited similar baseline scores. Following the intervention, ANOVA for repeated measurement revealed significant between-group effects (P < 0.05), time effects (P < 0.05), and interaction effects between groups and time (P < 0.05) in terms of eye movement grading. Postoperative improvements were observed in both groups at all follow-ups, with the combined strategy yielding superior outcomes at 1 and 3 months (P < 0.05). By 6 months, no significant differences were observed (P > 0.05). Before treatment, no significant differences were assessed in the incidence of CHP between the two groups (P > 0.05). After the intervention, the incidence of CHP was attenuated in both groups compared to preoperative levels (P < 0.05), although the postoperative difference between the two groups was not significant (P > 0.05). See Tables 2 and 3, as well as Figure 1 for details.
Comparison of esotropia improvement between the two groups
Both groups displayed a progressive improvement in esotropia correction over time, with rates increasing from 1 month to 6 months postoperatively. The combined group exhibited a higher esotropia improvement rate at 3 months post-treatment compared to the traditional group (P < 0.05). Nevertheless, there were no significant differences at 1 month and 6 months (P > 0.05). Refer to Table 4.
Table 4 Comparison of esotropia improvement between the two groups, n (%).
Groups
n
1 month after treatment
3 months after treatment
6 months after treatment
Combined group
28
13 (46.43)
22 (78.57)
28 (100.00)
Traditional group
29
10 (34.48)
15 (51.72)
26 (89.66)
χ2
0.844
4.508
3.057
P value
0.358
0.033
0.080
Comparison of the incidence of complications between the two groups
Postoperative complications in the combined group were limited to bulbar conjunctiva congestion and edema (3 cases). The traditional group exhibited a broader adverse event profile: 4 cases of bulbar conjunctiva congestion and edema, 1 case of muscle adhesion, 2 cases of secondary glaucoma, and 1 case of ASI. While the combined approach demonstrated a lower overall complication rate, this difference did not reach statistical significance (P > 0.05). See Table 5 for details.
Table 5 Comparison of the incidence of complications between the two groups, n (%).
Groups
n
Bulbar conjunctiva congestion and edema
Muscle adhesion
Secondary glaucoma
Anterior segment ischemia
Combined group
28
3 (10.71)
0 (0.00)
0 (0.00)
0 (0.00)
Traditional group
29
4 (13.79)
1 (3.45)
2 (6.89)
1 (3.45)
χ2
0.125
0.000
0.482
0.000
P value
0.723
0.986
0.487
0.986
DISCUSSION
At present, the pathogenesis of high myopia-associated strabismus remains incompletely understood. Demer et al[15] have reported new insights into orbital functional anatomy by identifying connective tissue sheaths in the tenon’s capsule, termed the “pulley”, through which extraocular muscles pass in the posterior orbit. Numerous studies have linked axial extension and orbital pulley abnormalities to disease progression, with magnetic resonance imaging evidence demonstrating morphological abnormalities in the lateral rectus-superior rectus band and displacements of the lateral and superior rectus muscles’ perforations[16-18]. Debate persists regarding the necessity of medial rectus muscle recession in surgical management. Durnian et al[19] corrected vertical and horizontal deviations in six patients using myopexy surgery alone, without performing medial rectus muscle recession. Similarly, Yamaguchi et al[20] reported that successful outcomes with loop myopexy in some patients without medial rectus contracture, suggesting it may not an indispensable part of highly myopic strabismus treatment. Conversely, proponents argue that medial rectus muscle recession is critical in cases of prolonged abduction limitation due to potential muscle contracture. Fresina et al[21] found that medial rectus muscle recession combined with loop myopexy surgery was performed on 33 eyes of 26 patients due to persistent abduction limitation during forced traction tests, showing remarkable improvements in diopter, esotropia, and abduction. Consistent with other reported studies, our findings demonstrated that at 1, 3, and 6 months postoperatively, both groups exhibited higher eye movement grades compared to baseline. Notably, the combined group outperformed the traditional group at 1- and 3-months, with esotropia improvement rates rising progressively, highlighting the synergistic benefits of integrating these techniques.
In patients with high myopia, excessive axial length leads to expansion in the posterior part of the eye, particularly at the junction of the retina and sclera. This structural change increases the tensile forces on the medial rectus, causing excessive inward pulling of the eyeball. Concurrently, the sclera thinning and retinal stretching further restrict the ocular motility[22-24]. Due to the elongated axial length, the medial rectus is in an overstretched state, increasing its inward pulling force, contributing to esotropia[25-27]. Besides, the alteration in the shape of the eyeball weakens the outward pulling force of the lateral rectus, impacting the eyeball’s external rotational movement. Modified Yokoyama surgery addresses these imbalances by adjusting the attachment points of superior and inferior oblique muscles to rebalance their biomechanical forces[28,29]. This adjustment mitigates the abnormal vertical and horizontal pulling of the oblique muscles on the eyeball, thereby correcting the angle of strabismus and improving visual alignment. One study also denoted[30] that modified Yokoyama surgery dramatically improved the range and control of eye movements in patients with high myopia, mitigating issues like eyeball retraction and rotation. Medial rectus muscle recession involves moving the attachment point of the medial rectus backward, attenuating its inward pulling force on the eyeball. This step is particularly important for correcting the angle of esotropia in patients with high myopia. Researchers found that this surgery was effective in correcting esotropia, vigorously improving the eye position and visual alignment post-surgery[31]. Other studies have reported that the surgery could redistribute the mechanical balance of extraocular muscles, enabling the lateral rectus to function more efficaciously and promoting external rotation of the eyeball[32-35]. The combination of modified Yokoyama surgery and medial rectus muscle recession addresses muscle imbalances caused by high myopia. On one hand, it alleviates the deformation of the posterior part of the eyeball by adjusting the position of oblique muscles; on the other hand, it attenuates the inward pulling force through medial rectus muscle recession, restoring overall eye movement balance. This multi-layered intervention not only corrects fixed esotropia but also improves multidirectional eye movement, providing patients with better visual alignment and eye flexibility in daily life. Postoperatively, patients exhibit expanded gaze range, improved stereopsis, and enhanced functional vision—critical for daily activities and high-performance visual tasks.
The incidences of bulbar conjunctiva congestion and edema 10.71% in the combined group and 13.79% the traditional group. These complications are likely attributable to the stimulation of eye tissues and surgery-associated inflammatory responses. No severe complications, such as muscle adhesion, secondary glaucoma, or ASI, were observed in the combined group. In contrast, the traditional group reported 1 case (3.45%) of muscle adhesion, 2 cases (6.89%) of secondary glaucoma, and 1 case (3.45%) of ASI, although the difference was not significant. Muscle adhesion may result from surgical trauma and the healing condition while secondary glaucoma may be caused by disruptions in aqueous humor circulation. ASI is likely caused by intraoperative damage of the ocular blood vessels. However, this study is limited by its small sample size and relatively short follow-up period (6 months), which may introduce bias and limit the generalizability of the findings. Future investigations with larger cohorts and extended follow-up durations are needed to validate these results and assess long-term safety.
CONCLUSION
By synergizing modified Yokoyama surgery and medial rectus muscle recession, the combined approach is not merely a simple procedural combination, but rather a biomechanical adaptation tailored to the unique pathoanatomy of myopic globes. Our results suggested the combined strategy is a safe and effective approach to improving eye movement and esotropia in highly myopia athletes with fixed esotropia, offering safe and considerable clinical benefits.
Footnotes
Provenance and peer review: Unsolicited article; Externally peer reviewed.
Peer-review model: Single blind
Specialty type: Medicine, research and experimental
Country of origin: China
Peer-review report’s classification
Scientific Quality: Grade B
Novelty: Grade B
Creativity or Innovation: Grade C
Scientific Significance: Grade C
P-Reviewer: Herszenyi L S-Editor: Lin C L-Editor: A P-Editor: Xu ZH
Chew-Ean T, Ghani SA, Shatriah I. Infantile esotropia in Malaysian children: The impact of surgery on health-related quality of life assessment in patients and their parents.Med J Malaysia. 2020;75:531-537.
[PubMed] [DOI]
Jorge J, Teixeira J, Pinhão T, Delgado F, Salem A, Martino F, Plainis S. Self-reported visual symptoms and high visual demand activities in professional football players: a cross-sectional survey.Front Sports Act Living. 2023;5:1256847.
[RCA] [PubMed] [DOI] [Full Text][Reference Citation Analysis (0)]
Demer JL, Miller JM, Poukens V, Vinters HV, Glasgow BJ. Evidence for fibromuscular pulleys of the recti extraocular muscles.Invest Ophthalmol Vis Sci. 1995;36:1125-1136.
[PubMed] [DOI]
Freitas-da-Costa P, Madeira MD. Functional anatomy of the orbit in strabismus surgery: Connective tissues, pulleys, and the modern surgical implications of the "arc of contact" paradigm.J Anat. 2024;244:887-899.
[RCA] [PubMed] [DOI] [Full Text][Cited by in Crossref: 1][Reference Citation Analysis (0)]
Wabbels B, Fricke J, Schittkowski M, Gräf M, Lorenz B, Bau V, Nentwich MM, Atili A, Eckstein A, Sturm V, Beisse C, Sterker I, Neppert B, Mauschitz MM. Yokoyama procedure for esotropia associated with high myopia: real-world data from a large-scale multicentre analysis.Acta Ophthalmol. 2021;99:e1340-e1347.
[RCA] [PubMed] [DOI] [Full Text][Reference Citation Analysis (0)]
Nakao S, Miyata M, Hirai M, Mizoguchi S, Ohashi H, Nishiwaki H. Rescue of exotropia subsequent to pulled-in-two syndrome of the medial rectus muscle occurring during surgery for high myopic strabismus fixus: A case report.Medicine (Baltimore). 2022;101:e31864.
[RCA] [PubMed] [DOI] [Full Text][Reference Citation Analysis (0)]
