Efficacy comparison of botulinum toxin A injection and extraocular muscle surgery in the treatment of large angle acute acquired concomitant esotropia / 国际眼科杂志(Guoji Yanke Zazhi)

AIM: To explore the variance in efficacy between botulinum toxin A(BTA)injection and extraocular muscle surgery in managing large-angle(≥+60 PD)acute acquired concomitant esotropia(AACE).METHODS: A retrospective analysis was conducted on clinical data of 60 patients with AACE treated at our hospital from June 2020 to December 2022. Patients were divided into three groups based on different treatments: 2.5 IU BTA injection group(14 cases), 5.0 IU BTA injection group(29 cases), and surgical group(17 cases). Follow-up was conducted for 6 mo after treatment to observe the degree of strabismus after the correction of refractive error, visual function, treatment effectiveness, and occurrence of complications after BTA injection.RESULTS: At 6 mo post-treatment, the degree of strabismus in the surgical group and the 5.0 IU BTA injection group was lower than that in the 2.5 IU BTA injection group(P<0.017). However, there was no significant difference in the degree of strabismus between the surgical group and the 5.0 IU BTA injection group(P>0.017). The effective rate of the 5.0 IU BTA injection group was higher than that of the 2.5 IU BTA injection group(86% vs 43%, P<0.017). There was no difference in visual function among the three groups(P>0.05). The incidence of complications after treatment was not significantly different between the 2.5 IU BTA injection group and the 5.0 IU BTA injection group(43% vs 52%, P>0.05).CONCLUSION: For AACE patients with esotropia degree ≥+60 PD, bilateral medial rectus injection of 5.0 IU BTA can yield outcomes comparable to traditional extraocular muscle surgery, with the advantages of minimal trauma and simple and convenient operation.

Study 3: Anterior segment optical coherence tomography-guided surgical approach in slipped medial rectus muscle

Purpose: To discuss the novel swept?source anterior segment optical coherence tomography (SS?ASOCT)?guided surgical approach in slipped medial rectus muscles. Methods: Prospectively (between February 2020 and July 2022), six patients with a clinical suspicion of slipped medial rectus muscle were recruited. After complete ophthalmic and orthoptic evaluation, the missing medial rectus muscle is screened using Anterior Segment Optical Coherence Tomography (ASOCT). In presence of a traceable muscle, its morphology, depth, and distance from a fixed anatomical landmarks were noted; in its absence, the status of other recti was noted. Intraoperatively, the features were confirmed and the intended intervention was performed. Results: The mean age of six patients was 25.66 ± 9.72 years, two with surgical trauma and four with penetrating trauma (66.66%). In five patients, the ASOCT traced the slipped medial rectus muscle successfully (83.33%); intraoperatively, the same was confirmed (within 1–2 millimeters) with favorable outcomes. ASOCT made a significant contribution in all subjects by reducing the number of interventions and muscle surgeries. Conclusions: In eyes with slipped medial rectus muscle, especially those which are within a finite distance from the angle can be traced using ASOCT. This approach impacts the outcomes in many ways

Clinical application of botulinum toxin type A in the treatment of thyroid-associated ophthalmopathy / 国际眼科杂志(Guoji Yanke Zazhi)

Thyroid-associated ophthalmopathy(TAO)is an autoimmune inflammatory disease involving multiple orbital tissues with a variety of clinical manifestations, which has serious effects on the life quality of patients.Interventions of TAO mainly include medical treatment to stabilize thyroid function, reduce inflammation and regulate immune function, as well as surgical treatment to relieve ocular symptoms. Botulinum toxin type A can paralyze muscles by blocking nerve impulse conduction at the neuromuscular junction, which is of certain therapeutic value for restrictive strabismus due to extraocular muscle involvement and upper eyelid retraction due to involvements of levator palpebrae superioris and Müller's muscle in TAO patients, especially when they have surgical contraindications, lack surgical opportunity, or refuse surgery. This paper reviews the application of botulinum toxin type A in the treatment of TAO, focusing on its pharmacological mechanism, dosage, effectiveness, and possible complications when treating restrictive strabismus and upper eyelid retraction, and discussing potential therapeutic values of botulinum toxin type A for intraocular pressure elevation, glabellar frown lines and dry eye caused by extraocular muscle compression in TAO patients, in order to provide a reference for clinical intervention.

Research progress of retinal microscopic changes after extraocular muscle surgery / 国际眼科杂志(Guoji Yanke Zazhi)

As a primary treatment for strabismus, extraocular muscle surgery can achieve the purpose of correcting the eye position, improving the appearance and reconstructing the third-level visual function. Previous studies have found that the vascular density(VD)and thickness of retina increased in the early stage after extraocular muscle surgery, where multiple mechanisms involved. In recent years, with the appearance of detection means such as optical coherence tomography angiography(OCTA), our quantitative understanding of retinal microscopic changes and their mechanisms brought about by traditional extraocular muscle surgery has become more and more profound. The increase of retinal VD in the early postoperative period may be closely related to the recovery of postoperative visual function. However, the related studies are few, and the association between microscopic changes and visual function after extraocular muscle surgery and its mechanism need to be further clarified. This article will review the microscopic changes of retina and their mechanisms after extraocular muscle surgery from multiple perspectives to improve our understanding of the relationship between the mechanism of its influence and visual function, with a view to provide references for the choice of extraocular muscle surgery scheme and related clinical research.

Research progress of anterior segment ischemia after extraocular muscle surgery / 国际眼科杂志(Guoji Yanke Zazhi)

@#Anterior segment ischemia(ASI)is a rare but serious complication after extraocular muscle surgery. Due to its complex clinical manifestations, it is easy to be misdiagnosed. If not treated in time, it may lead to blindness such as vision loss. This paper mainly reviews the concept, clinical manifestations, pathogenesis, risk factors, diagnosis and treatments of ASI after extraocular muscle surgery, so as to improve people's understanding of ASI and minimize or avoid the occurrence of ASI in clinical work.

Thyroid-Associated Orbitopathy: Evaluating Microstructural Changes of Extraocular Muscles and Optic Nerves Using Readout-Segmented Echo-Planar Imaging-Based Diffusion Tensor Imaging

OBJECTIVE: We aimed to investigate the ability of readout-segmented echo-planar imaging (rs-EPI)-based diffusion tensor imaging (DTI) in assessing the microstructural change of extraocular muscles (EOMs) and optic nerves in patients with thyroid-associated orbitopathy (TAO) as well as in evaluating disease activity.MATERIALS AND METHODS: We enrolled 35 TAO patients and 22 healthy controls (HCs) who underwent pre-treatment rs-EPI-based DTI. Mean, axial, and radial diffusivity (MD, AD, and RD) and fractional anisotropy (FA) of the medial and lateral EOMs and optic nerve for each orbit were calculated and compared between TAO and HC groups and between active and inactive TAO groups. Factors such as age, sex, disease duration, mediation, and smoking history between groups were also compared. Logistic regression analysis was used to evaluate the predictive value of significant variables for disease activity.RESULTS: Disease duration was significantly shorter in active TAOs than in inactive ones (p < 0.001). TAO patients showed significantly lower FA and higher MD, AD, and RD than HCs for both medial and lateral EOMs (p < 0.001), but not the AD value of lateral EOMs (p = 0.619). Active patients had significantly higher FA, MD, and AD than inactive patients for medial EOMs (p < 0.005), whereas only FA differed significantly in the lateral EOMs (p = 0.018). The MD, AD, and RD of optic nerves were significantly lower in TAO patients than HCs (p < 0.05), except for FA (p = 0.129). Multivariate analysis showed that the MD of medial EOMs and disease duration were significant predictors for disease activity. The combination of these two parameters showed optimal diagnostic efficiency for disease activity (area under the curve, 0.855; sensitivity, 68.4%; specificity, 96.9%).CONCLUSION: rs-EPI-based DTI is promising in assessing microstructural changes of EOMs and optic nerves and can help to indicate the disease activity of TAO, especially through the MD of medial EOMs.

Corneal curvature and refractive state changes after microscopically extraocular muscle surgery in adults / 国际眼科杂志(Guoji Yanke Zazhi)

@#AIM: To investigate the corneal curvature and refractive changes after microscopically extraocular muscle surgery in adults.<p>METHODS: To observe 62 cases of 85 eyes underwent microscopic extraocular muscle surgery in the Second People's Hospital of Yunnan Province from December 2016 to May 2017, age 18 to 43, according to the surgical method, patients were divided into horizontal rectus surgery: Ⅰ group(simple migration group)32 eyes, Ⅱ group(rectus monocular migration combined with its antagonist muscle excision group)34 eyes, the oblique muscle group: Ⅲ group(single oblique muscle tendon broken group)10 eyes, Ⅳ group(oblique muscle transposition group)9 eyes; Subjective optometry was performed preoperatively and postoperatively at 1d, 1wk, 1mo, 3mo and 6mo, respectively, to obtain the refractive state changes and the curvature value of the anterior surface of the cornea(0-3mm, 5mm, 7mm)collected by corneal topography. The dynamic changes of the refractive state and corneal morphology of the patients in each group at different time points were compared. Anova and LSD-<i>t</i> test were used for comparison among time points and within each group.<p>RESULTS: Changes of corneal curvature in horizontal rectus muscle can be induced in a short period after the operation, which is limited to the central 5mm area of the cornea, and basically restored to the preoperative level 1mo after the operation. There was no significant effect on corneal curvature after inferior oblique operation. Astigmatism value increased in the early postoperative period of horizontal rectus muscle; Myopic drift occurred and recovered to preoperative level 1mo after surgery. After the operation of the inferior oblique muscle, there was no significant change in the spheroscopy and astigmatism.<p>CONCLUSION:Corneal curvature and refractive changes may occur after extraocular muscle in adults.

Extraocular muscle surgery on goats' eye: An inexpensive technique to enhance residents' surgical skills

Hands-on resident surgical training for various ocular procedures is essential to impart good surgical skills to the budding ophthalmologists. Here in this report, we demonstrate a simple and inexpensive technique of performing extraocular muscle surgery on goats' eye. These animal eyes possess soft tissue resemblance to that of human eyes to a greater extent in terms of scleral rigidity, muscle elasticity, its width, thickness, and its insertion onto the sclera. Therefore, rectus muscle recession, resection, and plication surgeries can be performed repeatedly to improve an individual's orientation and practical experience before performing the procedure on human eyes.

Pulled into two syndrome (PITS) in a case of congenital fibrosis of the extraocular muscle

A four-year-old child with a clinical diagnosis of unilateral congenital fibrosis of extraocular muscles (CFEOM) was planned for inferior and medial rectus muscle recession surgery, adjusted with the status of forced duction test. Due to pathological changes within the muscles subsequent to innervational abnormality, intraoperatively the inferior rectus muscle was pulled into two following the insertion of muscle hook. Moreover, the snapped muscle fibers could not be identified, thus further surgery was abandoned and an observation was commenced. At the end of 6 weeks, there was a significant reduction in the amount of hypotropia but clinically significant perverted convergence with esotropia necessitated further surgical intervention. A second surgical intervention consisting of medial rectus transposition to superior rectus with 3 mm recession was performed to achieve acceptable results in the primary gaze.

Clinical observation of monocular rectus surgery for adult sensory exotropia / 国际眼科杂志(Guoji Yanke Zazhi)

@#AIM:To evaluate the effect of monocular rectus surgery for adult sensory exotropia. <p>METHODS: Totally 76 cases of adult sensory exotropia of degree -15^△ to -160^△(-68.36^△±30.77^△)examined through Krimsky method were included into this study. A total of 16 cases, 37 cases and 23 cases with different degrees of strabismus were treated separately with routine amount monocular lateral rectus recession, routine amount monocular medial rectus resection plus lateral rectus recession, and exceed constant amount monocular medial rectus resection plus lateral rectus recession. Follow-up was performed at 1d, 1wk, 1, 3 and 6mo after operation. The eye position, monocular movement, intraocular pressure(IOP), slit lamp, and fundus of these patients were examined. <p>RESULTS:After surgery, 67 cases(88%)were positive and 9 cases(12%)were undercorrection. The postoperative intraocular pressure of operative eye at 1wk was equal to preoperative(<i>P</i>=0.090), and IOP decreased to a valley value at 1mo(<i>P</i><0.01), there was no significant difference in intraocular pressure between 3mo and 1mo(<i>P</i>=0.092), and no significant difference in intraocular pressure between 6mo and 3mo(<i>P</i>=0.123). And 2 cases(3%)had inflammatory reaction induced by anterior segment ischemia at 1d and 1wk postoperative visits, and they recovered at 1mo follow-up visit; 4 cases(5%)experienced an external dysfunction at the 1, 3 and 6mo follow-up. <p>CONCLUSION:Monocular rectus surgery has a good therapeutic effect on adult patients with sensory exotropia; the decrease in intraocular pressure secondary to the detached rectus is worth the attention of the surgeon; the incidence of complications after detaching monocular of two rectus muscles is comparable low. Exceed constant amount rectus strabismus surgery for sensory exotropia may result in limited function of postoperative ocular hyperextension.

A New Model of Extraocular Muscle Fibrosis by Thermal Cauterization in the Rats

PURPOSE: To evaluate the effect of cauterization on extraocular muscle (EOM) fibrosis in rats, and to develop a novel EOM fibrosis model. METHODS: Twenty-four eyes of 12 Sprague Dawley rats were assigned randomly to two groups. We exposed the superior rectus muscle (SRM) and performed thermal injury 2 mm behind the insertion site of the SRM using a cautery device in the experimental group. The thermal injuries were performed twice for 1 second, for a total of 2 seconds. In the control group, the same procedures except the thermal injury were performed. Two weeks after surgery, all eyes were enucleated and stained with hematoxylin and eosin (H&E) and Masson's trichrome (MT). RESULTS: Staining with H&E and MT showed that thermal injury significantly increased inflammation and fibrosis in the experimental group (p=0.002, p < 0.001, respectively). CONCLUSIONS: Thermal injury using cauterization effectively induced fibrosis of EOM in the rat model. This simple model was effective in inducing fibrosis of SRM and will be useful for studying postoperative fibrosis after strabismus surgery.

The value of the signal intensity ratio of the extraocular muscle and the ipsilateral white matter of the MRI in the evaluation of the activity of thyroid-associated ophthalmopathy / 中华内分泌代谢杂志

Objective To investigate the quantitative value of the signal intensity ratio of extraocular muscle and ipsilateral white matter measured by MRI for the evaluation of activity in thyroid-associated ophthalmopathy. Methods A total of 129 patients and 245 eyeballs with thyroid-associated ophthalmopathy were enrolled in this study and this 245 eyeballs were set as thyroid-associated ophthalmopathy group(TAO group). There were 10 patients with newly diagnosed Graves'disease and in the same period and these 20 eyeballs were set as graves'disease group(GD group). 32 normal people from annual physical test excluded thyroid and eye diseases and their 64 eyes were selected randomly for the normal control group(NC group). The signal intensity of the extraocular muscle and the ipsilateral white matter on the MRI images were measured, while did exophthalmos and the width of the inner fat of eyeballs (FWs)measurements in the same time. Results SIR,FWs,and exophthalmos of TAO group were higher than those of the other 2 groups[SIRs:1.71(1.40,2.10)vs 1.26(1.22,1.34)and 1.23(1.14,1.32);FWs:8.04(6.70, 8.71)mm vs 6.16(4.86,7.08)mm and 6.93(6.41,7.65)mm,exophthalmos:20.10(18.56,22.15)mm vs 15.40(14.87,16.60)mm and 14.73(13.40,16.07)mm,all P<0.05]. The reference value of SIR establishing based on SIRs of NC group is less than 1.37. In total 129 TAO patients,55 patients(with 106 eyeballs)have a clinical activity score(CAS). Then,these eyeballs were grouped to activity and non-activity(grouped by CAS≥3),and the baseline group difference of these 2 groups was not statistically significant. The SIRs and exophthalmos of activity group were higher than the non-activity group[SIRs:1.70(1.45,2.33)vs 1.41(1.25,1.75); exophthalmos:(20.38 ± 2.40)mm vs(19.05 ± 3.70)mm,all P<0.05]. But the difference of FWs of these two groups was not statistically significant(P>0.05). The SIRs and CAS had a positive correlation(r=0.580,P=0.000),through the receiver operating characteristic curve(ROC)we get the best diagnostic performance of TAO activity when the SIR≥1.56(sensibility=65.6%,specificity=89.1%,AUC=0.815,P=0.000). Conclusion The signal intensity ratio of extraocular muscle and ipsilateral white matter may discriminate the activity of TAO early as a quantitative indicator, reflecting its efficacy,and is worth clinically generalizing.

Two Cases of Extraocular Muscle Enlargement Caused by Metastatic Cancer

PURPOSE: To report two cases of extraocular muscle enlargement due to malignant cancer metastasis. CASE SUMMARY: A 56-year-old woman presented with horizontal diplopia first noted 1 month earlier. She had a history of small cell lung cancer with brain and bone metastases. She had a -3 abduction deficit in the right eye and esotropia. The forced duction test showed no limitation in horizontal movement. Antibody tests for thyroid disease showed normal results. Brain magnetic resonance image showed multiple nodular enlargements of the right lateral and medial rectus muscles, al so multiple metastatic nodules in the brain. A 38-year-old woman presented with horizontal diplopia first noted 3 months previously. She had undergone breast cancer surgery 6 months earlier. The patient had a -4 abduction deficit in the left eye and esotropia. The forced duction test showed no limitation in horizontal movement. Antibody tests for thyroid disease showed normal results. Orbital magnetic resonance imaging showed nodular enlargement of left lateral rectus muscle including a tendon. CONCLUSIONS: Extraocular muscle metastasis is a possible cause of extraocular enlargement and paralytic strabismus. In a patient with malignant cancer, the physician should consider the possibility of extraocular muscle metastasis and perform imaging for early diagnosis and treatment.

A Case of Traumatically Ruptured Medial and Inferior Rectus Muscles with an Avulsed Optic Nerve

PURPOSE: To report the good surgical results of multiple ruptured rectus muscles with avulsion of the optic nerve. CASE SUMMARY: A 39-year-old male patient underwent surgical exploration after rupture of the inferior and medial rectus muscles and avulsion of the optic nerve. The disinserted muscles were attached at the primary insertion site, and a served optic nerve was not found. Six months after the injury, the patient had orthotropia in the primary position without ischemia of the anterior segment. CONCLUSIONS: In rare instances, blunt trauma can result in optic nerve avulsion with ruptured inferior and medial rectus muscles. Surgical treatment can result in a favorable outcome.

Comparison of Patient Characteristics in Thyroid-Associated Ophthalmopathy with and without Strabismus

PURPOSE: To determine immunochemical and clinical differences in thyroid-associated ophthalmopathy (TAO) patients with restrictive strabismus and without strabismus. METHODS: A retrospective chart review of 15 TAO patients with strabismus (25 eyes) and 24 TAO patients without strabismus (39 eyes) who presented to the Ophthalmology Clinic between August 2011 and December 2013 was performed. Visual acuity, intraocular pressure (IOP), Hertel exophthalmometry, soft tissue score, and enlargement of extraocular muscles on computed tomography (CT) were obtained and compared in each group. Thyroid related autoantibody (thyroid-stimulating hormone receptor antibody, TRAb; thyroid peroxidase antibody, TPOAb; anti-thyroglobulin antibody, TgAb) titers and positive rates were obtained at the time of diagnosis or before treatment and analyzed. RESULTS: The gender and smoking proportion were not significantly different between the 2 groups. The mean age of TAO patients with strabismus was 52.53 years and of TAO patients without strabismus 40.33 years (p = 0.004). The differences in visual acuity and IOP between the 2 groups were not significant. Hertel exophthalmometry showed less proptotis in the TAO with strabismus group than the TAO without strabismus group (16.84 mm versus 18.67 mm). The soft tissue score was not significantly different. The extraocular muscle enlargement rate of TAO with strabismus was significantly higher than in TAO without strabismus group. In the TAO with strabismus group, TRAb level was higher than in the TAO without strabismus group (p = 0.021). CONCLUSIONS: The TAO with strabismus group was older and had higher positive rate, level of TRAb, and extraocular muscle enlargement rate on CT than the TAO without strabismus group. Furthermore, proptosis was less definite in the TAO with strabismus group.

A Case of an Isolated Abscess in an Extraocular Muscle

PURPOSE: To report the case of an isolated abscess in an extraocular muscle. CASE SUMMARY: We report a case of an isolated abscess in an extraocular muscle in a patient who was treated with systemic chemotherapy for precursor B lymphoblastic leukemia. A 54-year-old female who had undergone systemic chemotherapy for precursor B lymphoblastic leukemia presented with right ocular pain and limited eye movements. On ophthalmic examination, she had elevated intraocular pressure (IOP) and limited upward and downward gaze. MRI (magnetic resonance imaging) examination revealed an isolated abscess in right inferior rectus muscle. Although the patient was treated with empirical intravenous antibiotics and IOP-lowering agents, the size of the abscess increased, as confirmed by MRI findings. Therefore, we performed a pus drainage procedure by the transconjunctival approach. We were not able to find any residual abscess lesions on CT scans 3 months postoperatively. The patient's ocular pain disappeared and the limited eye movements improved significantly 6 months postoperatively. CONCLUSIONS: There have been no case reports of an isolated abscess in an extraocular muscle in Korea. For immunocompromised patients unresponsive to systemic empirical antibiotic treatment, an early pus drainage procedure by the transconjunctival approach may be a useful and effective therapeutic method in the management of an idiopathic isolated abscess in an extraocular muscle.

A Case of MALT Lymphoma with Left Inferior Rectus Muscle Invasion

PURPOSE: To report an unusual case of mucosa-associated lymphoid tissue (MALT) lymphoma localized to the left inferior rectus muscle. CASE SUMMARY: A 52-year-old male presented with double vision 6 months in duration, which was exacerbated in the down-gaze. On initial examination, 6 and 30 prism diopters (PDs) of left hypertropia were observed in primary gaze and down gaze, respectively. Prominently limited infraduction was also observed in his left eye. Computed tomography (CT) revealed contrast enhancing mass on the left inferior rectus muscle. He was diagnosed with suspicious orbital pseudotumor and treated with systemic steroid for 2 months. Double vision and limited infraduction was improved and the mass size was decreased on CT. After 21 months, the patient revisited the clinic with the same symptoms. In the down-gaze, 35 PDs of hypertropia were observed in his left eye along with limited infraduction. CT revealed an enlarged mass and left superior rectus muscle recession along with an incisional biopsy of the left inferior rectus muscle were performed. Infiltration by small lymphoid cells was detected with hematoxylin-eosin and immunohistochemical stainings. Subsequently, the patient was diagnosed with MALT lymphoma localized to the left inferior rectus muscle. CONCLUSIONS: This is the first description of MALT lymphoma with inferior rectus muscle invasion in a Korean patient. In a patient with strabismus and limited duction, the possibility of extraocular muscle tumor including lymphoma should be considered. Homogenously contrast-enhanced mass on orbit CT can help in to make a diagnosing extraocular muscle lymphoma.

Influence of triamcinolone acetonide on peribulbus tissues via periocular injection / 中华实验眼科杂志

Background Triamcinolone acetonide (TA) is often used in the treatment of uveitis and fundus disease,but whether it has toxic effect to normal tissue around eyes is unclear.Objective The aim of this study was to explore the adverse and toxic effects of TA on the periorbitally normal tissue following the periocular injection.Methods Twenty-seven New Zealand albino rabbits were randomly divided into experimental group,normal saline solution group and blank control group.TA was periocularly injected twice (20 mg for each) at 1-month interval in the rabbits of the experimental group,and 0.5 ml normal saline solution was used in the same way in the rabbits of the normal saline solution group.Not any drug was used in the blank group.The rabbits were sacrificed 1 month and 2 months,3 months after the secondary injection.For the preparation of the specimens of extraocular muscles,peribulbus adipose tissue,lacrimal gland and optic nerve.Hematoxylin and eosin staining of the specimens was performed to examine the the pathological change under the optical microscope,and the ultrastructural of peribulbus tissues was observed under the transmission electron microscope.Results No statistically significant change was found in IOP among various time points and groups (Fgroup =0.952,P =0.881 ; Ftime =7.297,P =0.411).The hyphological structures and ultrastructure of extraocular muscles,peribulbus adipose tissue,lacrimal gland and optic nerve were normal in the rabbits of the normal saline solution group and the blank control group.However,the optical microscopy showed varying degrees of atrophy or dissolving in the extraocular muscle fibers,the increase of glandular epithelial cells and enlargement of nuclei in the lacrimal gland as well as visible disorder arrangement of nerve fibers,vacuoles degeneration and the decrease of glial cells in optial nerve tissue in the rabbits of the experimental group from 1 month though 3 months after the secondary injection.Under the transmission electron microscope,the muscle stripes,bright band and dark band were incompletely disappeared,and expansionary sarcoplasmic reticulum and oval nucleus at the inferior to sarolemma were seen in the extraocular muscles.In addition,swelling lacrimal gland epithelial cells,thickening nuclear membrane and more organelles were exhibited in the lacrimal gland.In the optic never tissue,uneven myelin,space between axons and myelin,lamellar separation and degeneration also were revealed in the rabbits of the experimental group after injection of TA.Peribulbus adipose tissue was near normal both by optical microscope and transmission electron microscope in the experimental group.Conclusions The periocular injection of TA dose not elevated the IOP.However,it will result in the histogical and ultrastructural damages of extraocular muscles,lacrimal gland and optic nerve.

Analysis of the structure and function of the extraocular muscle connective tissue in rabbit / 中华实验眼科杂志

Background The extraocular muscles (EOMs) Pulley in primate is related to the function of EOMs,but there are arguments about that.The location of rabbit's eyes is different from the primate.Study on the structure of the extraocular muscle connective tissue in rabbit may play a role to analyze the function of the EOMs Pulley.Objective The structure of the connective tissue around EOMs in rabbit was studied,the difference between this structure in rabbit and homan' s EOMs Pulley in past reports was analyzed,and then,the role of EOMs Pulley to ocular movement was investigated.Methods Five adult rabbits were involved.The gross anatomy of an orbit in each rabbit was observed.The other orbit was processed with paraffin imbedding and coronal serial sections.A murine monocolonal antibody to α-smooth muscle actin(α-SMA) was used to show the smooth muscle,while Weigert stain was used to show muscle and collagen,and Masson trichrome stain to show the elastin.Results An encircling ring of collagen circled every EOM.The collagen ring was thin and connected to the orbital layer muscle fiber loosely.Collagen tissues coupled to adjacent EOMs.Less elastin fibers and scanty the smooth muscle cells were embedded in the collagen.Conclusions The connective tissue around rectus in rabbit is different from that in human with developed binocular ocular movements.It shows that connective tissue around EOMs may be related to the function of ocular movements.

Decorin and TGF-beta Expression after Partial Myotomy of the Extraocular Muscle in Rat

PURPOSE: To report the expression of decorin and TGF-beta in partial myotomy of the extraocular muscle in rats. METHODS: Partial myotomy of the superior rectus muscle was performed on the right eye of 10 Sprague-Dawley rats followed by exposure of the left superior rectus muscle and a simple suture of the conjunctiva. The bilateral superior rectus muscle was obtained from all rats at 2 weeks postoperatively. The tissues were observed under light microscopy with hematoxylin-eosin, Masson's trichrome staining and immunohistochemistry. RESULTS: Histological examinations of the surgical area at 2 weeks after postoperatively showed irregularly concentrated fibrosis on light microscopy with hematoxylin-eosin and Masson's trichrome staining of the experimental eyes. Immnohistochemistry showed that expression of decorin was in the same location as TGF-beta in the experimental group. CONCLUSIONS: The expression of decorin was found in the healing process after partial myotomy of the extraocular muscle in rats. Immunohistochemistry showed that expression of decorin was in the same location as with TGF-beta.