Overaction of the inferior oblique(IO) muscle is manifested by elevation of the adducted eye and from the clinical point of view there are two types of overaction. The primary type is of unknown cause, whereas the secondary type is usually related to the palsy of the ipsilateral superior oblique or contralateral superior rectus. An ultrastructural study on the overacting IO muscles was performed compared to normal IO muscles by electron microscopy. Of 16 biopsies of overacting IO muscles, four had primary overacting inferior obliques and twelve had secondary overacting inferior obliques due to paralysis of superior oblique muscle. Additional four IO muscle, obtained from patients with intraocular diseases served as control specimens. The most striking abnormalities were aggregations of mitochondria and degenerating mitochondrial profiles and increased vacuolization in primary and secondary overacting muscles. Many muscle fibers were in different stages of atrophy, and hypertrophy and regeneration of muscle fibers were sometimes visible. The results suggest that the primary overacting IO muscle might be the result of a paresis of the superior oblique muscle.
Biopsy ; Humans ; Mitochondria/ultrastructure ; Ocular Motility Disorders/*pathology ; Oculomotor Muscles/*ultrastructure ; Ophthalmoplegia/pathology ; Vacuoles/ultrastructure

Using a rabbit model, we assessed the postoperative status and histopathologic findings of superior oblique tenotomy with silicone expander procedure. In the control group we marked and cut the superior oblique, and in the experimental group we inserted a silicone 240 retinal band 4 mm in length along the edges of incision. At the postoperative weeks 1,3,5 and 7, we randomly chose five rabbits and made a histopathologic examination after hematoxylin-eosin and Masson's trichrome stain. The distance between the incised edges was various in the control group, but constant in the experimental group. With time inflammation decreased and fibrosis of the superior oblique increased. Foreign body reaction occurred around the suture material in both groups., but not around the silicone expander. At 5 weeks atrophy of the superior oblique was observed in both groups.From the above results, we concluded that the superior oblique lengthening procedure using silicone expander is a useful surgical method for weakening the superior oblique muscle.
Animals ; Female ; Fibrosis ; Male ; Oculomotor Muscles/pathology/*surgery ; Rabbits ; *Silicone Elastomers ; Tendons/pathology/*surgery

OBJECTIVE: To investigate histopathologic and ultrastructural changes of extraocular muscles (EOM) in thyroid associated ophthalmopathy (TAO). METHODS: Twelve EOM specimens from 11 patients with TAO were observed. Each of the specimen was stained with HE and observed by light microscope,and then was sectioned with ultrathin method and observed by transmission electronic microscope. RESULTS: Under the light microscope, sarcoplasm coagulation,granular degeneration, vacuolization and necrosis were found in the extraocular muscular cells.Under the electronic microscope, there were disturbance and disappearance of the Z line in part of muscular fibers and various degrees of sarcoplasmic reticulum dilatation, myofilament lysis and destruction with formation of vacuoles.In severe cases,the muscular cells could be completely destroyed and phagocytosed by macrophages,fibrosis occurred and myofibroblasts were found in some cases. CONCLUSION The extraocular muscles in TAO are destroyed at various degrees,and the muscular cells may be the target cells in TAO.
Adult ; Aged ; Female ; Graves Ophthalmopathy ; pathology ; Humans ; Male ; Middle Aged ; Oculomotor Muscles ; pathology ; ultrastructure

Ocular myasthenia gravis(OMG)is an autoimmune disease caused by neuromuscular junction transmission disorders and manifested mainly as fluctuating blepharoptosis and diplopia,with the extraocular muscles as the main involveed sites.While the pathogenesis of OMG remains unclear,some antibodies,complements,and cytokines may be the contributing factors.The diagnosis and treatment of OMG have been defined in recent years.This article reviews the pathogenesis,diagnosis,and treatment of OMG.
Antibodies ; Complement System Proteins ; Cytokines ; Humans ; Myasthenia Gravis ; diagnosis ; pathology ; therapy ; Oculomotor Muscles ; pathology

Adult ; Female ; Humans ; Lymphoma ; diagnosis ; Magnetic Resonance Imaging ; methods ; Male ; Middle Aged ; Oculomotor Muscles ; pathology

To evaluate the histopathologic changes after an inferior oblique marginal myotomy with local injection of triamcinolone, an inferior oblique marginal myotomy was performed in 14 white rabbits and they were divided into 2 groups, one group with a local injection of triamcinolone and the other group without triamcinolone injection after a myotomy. At the postoperative one month, an edema of the muscle fibers and an infiltration of the inflammatory cells were observed and at postoperative three months, a fibrous tissue ingrowth around the muscle fibers and an atrophy of the muscle fibers were found and those changes were less prominant in the group with triamcinolone injection. The local injection of triamcinolone after the inferior oblique marginal myotomy would help in decreasing the fibrous tissue ingrowth and the formation of the scar tissue, thus it could be used in augmenting the effect of the inferior oblique marginal myotomy.
Animals ; Atrophy ; Edema ; Eye Diseases/pathology ; Injections ; Oculomotor Muscles/drug effects/*pathology/*surgery ; Rabbits ; Triamcinolone/administration & dosage

To evaluate the histopathologic changes after an inferior oblique marginal myotomy with local injection of triamcinolone, an inferior oblique marginal myotomy was performed in 14 white rabbits and they were divided into 2 groups, one group with a local injection of triamcinolone and the other group without triamcinolone injection after a myotomy. At the postoperative one month, an edema of the muscle fibers and an infiltration of the inflammatory cells were observed and at postoperative three months, a fibrous tissue ingrowth around the muscle fibers and an atrophy of the muscle fibers were found and those changes were less prominant in the group with triamcinolone injection. The local injection of triamcinolone after the inferior oblique marginal myotomy would help in decreasing the fibrous tissue ingrowth and the formation of the scar tissue, thus it could be used in augmenting the effect of the inferior oblique marginal myotomy.
Animals ; Atrophy ; Edema ; Eye Diseases/pathology ; Injections ; Oculomotor Muscles/drug effects/*pathology/*surgery ; Rabbits ; Triamcinolone/administration & dosage

We report two patients with unilateral vertical retraction syndrome. Magnetic resonance imaging (MRI) of the orbits of the two cases showed similar size and location of the orbital structure, but with dramatically different strabismus type. MRI sagittal reconstruction of the orbits suggested that abnormal muscle tissue arised from the inferior rectus, which might be associated with retraction and narrowing of the palpebral fissure and atypical strabismus as well.
Child ; Eyelids ; physiopathology ; Female ; Humans ; Magnetic Resonance Imaging ; Male ; Oculomotor Muscles ; physiopathology ; Orbit ; pathology ; Strabismus ; pathology ; Syndrome

OBJECTIVETo evaluate the feasibility of high-field magnetic resonance in measuring the thickness and width of extraocular muscles, calculate the ratio of thickness to width, and summarize the characters of the diameters and its ratio in patients with Graves' ophthalmopathy (GO) with upper-lid retraction.

METHODSSixteen GO patients with upper-lid retraction (GO group) and 14 healthy control group were enrolled in this study. All the patients underwent enhanced high-field magnetic resonance orbital scan. The thickness and width of extraocular muscles were measured on axial, coronal or oblique sagittal enhanced T1 weighted images. The ratio of thickness to width (R1) and width to thickness (R2) were calculated. The diameters or ratio was evaluated as enlarged when they were 2 standard deviation greater than mean values of extraocular muscle in healthy control.

RESULTSThe thickness of levator palpebrae superioris, medial rectus, and inferior rectus muscles in GO group were significantly larger than those in the control group (P=0.000, P=0.017, P=0.032, respectively. The width of superior oblique muscles in GO group was significantly larger than that in control group (P=0.000). The R1 values of levator palpebrae superioris, inferior rectus, medial rectus, and lateral rectus muscles in GO group were significant larger than those in the control group (P=0.000,P=0.037, P=0.019,P=0.032, respectively. The R2 value of superior oblique muscles was significant larger than that in the control group (P=0.027). Aslo in GO group, 32 extraocular muscles showed an increased thickness. 47% of thickened extraocular muscles had an increased R1.

CONCLUSIONSEnhanced orbit imaging with high-field magnetic resonance is helpful in the quantitative assessment of the thickness and width of extraocular muscles. In GO patients, in addition to the levator palpebrae superioris muscles, some other extraocular muscles also becomes thicker. Moreover, the increased diameters of superior oblique muscles is mainly due to the increase of its width R1 and R2 values can reflect the thickness and width of extraocular muscles and their relationship.

Adult ; Case-Control Studies ; Female ; Graves Ophthalmopathy ; pathology ; Humans ; Magnetic Resonance Imaging ; Male ; Middle Aged ; Oculomotor Muscles ; pathology

A 53-year-old woman complaining of vertical diplopia, presented with a localized swelling in the right lower lid. Magnetic resonance imaging studies demonstrated a relatively well-defined mass in the inferior rectus with similar signal characteristics to the muscle. Excisional biopsy of the mass revealed granular cell tumor composed of S-100 positive cells with acidophilic granular cytoplasm and a peripheral lymphocytic infiltration. Granular cell tumor, which is very rare in the orbit, should be considered in the differential diagnosis of tumors adjacent to or within the extraocular muscles, particularly in the inferior orbit.
Biopsy ; Diagnosis, Differential ; Eye Neoplasms/*pathology ; Female ; Follow-Up Studies ; Granular Cell Tumor/*pathology ; Humans ; Magnetic Resonance Imaging ; Middle Aged ; Muscle Neoplasms/*pathology ; Oculomotor Muscles/*pathology