The Surgical Effect of Posterior Fixation Suture in Incomitant Strabismus

PURPOSE: To know the surgical effect and the indication of posterior fixation suture in incomitant strabismus. METHODS: From January 2003 to October 2004, posterior fixation sutures were used in five patients with strabismus after orbital wall fracture and in three patients with high AC/A accommodative esotropia. Using Worth 4-dot tests, we compared the amount of incomitant deviation before and after surgery. RESULTS: The mean decrease in deviation after surgery was 7.8+/-2.6PD(P=0.04) in patients with strabismus after orbital wall fracture, and 11.3+/-4.2PD in those with high AC/A ratio accomodative esotropia. CONCLUSIONS: The posterior fixation suture was effective in reducing the amount of incomitant deviation occurring in cases of strabismus after orbital wall fracture and cases of high AC/A accommodative esotropia.

Use of Tissue Adhesives in Experimental Porterior Fixation Suture

Inadvertent perforation of the globe, granuloma and hypersensitivity reaction have been recognized complications of the strabismus surgery. We performed experimental strabismus surgery with No.240 retinal band and histoacryl(group I), histocracyl only(group II), 6-0 vicryl(group III) in rabbit model to determine whether these techniques can replace the classic suture and decrease its complications. We measured maximum adhesion power by force gauge and observed histopathologic findings after sacrificing four rabbits at 1 day, 1 week, 4 week, and 8 weeks, respectively following experimental strabismus surgery. There were chronologically increasing tendency of adhesion power in all groups but no statistically significant differences among three groups. Pathologically inflammatory and foreign body reactions were decreased with time and there were no differences of inflammatory reactions among three groups. At four weeks after the experiment, there was encapsualation lined with loose fibrous tissue around the band in group I.In conclusion, We found that experimental strabismus surgery with tissue adhesives and No.240 retinal band showed good adhesion power and minimal tissue reaction. So, it is possible to do posterior fixation suture with tissue adhesive and No.240 retinal band in classic strabismus surgery.

Surgical Results of Duanes Retraction Syndrome

The authors reviewed medical records of 25 patients undergoing treatment for Duanes retraction syndrome. The patients were treated with appropriate horizontal muscle recession with or without posterior fixation suture, transposition procedures, and lateral rectus Y split and recession in order to relieve face turn, significant tropia in primary position, and upshoot or downshoot. The deviation in primary position was reduced by an average or 20.5 prism diopters; 19.5 prism diopters in horizontal muscle recession with or without posterior fixation suture, and 17.4 prism diopters in lateral rectus Y split and recession. The face turn was eliminated in 84%, while 100% in horizontal muscle recession with posterior fixation suture. The upshoot or downshoot was essentially corrected by lateral rectus Y split and recession(100%). Motility of the eye was not increased following each surgical procedures. According to the results, we could obtain appropriate deviation in primary position with each surgery postoperatively. Horizontal muscle recession with posterior fixation suture was effective in eliminating the face turn. Lateral rectus muscle Y-split and recession effectively corrected upshoot and downshoots.

Surgical Effect of Type I Nystagmus Blockage Syndrome

Six patients of nystagmus blockage syndrome (type 1) underwent both medial rectus recession and posterior fixation suture. Associated amblyopia wsa treated with occlusion or atropinization before and after surgery. During follow-up period for 12 weeks (4-36 weeks), four patients revealed orthophoria and one was esotropi a less than 5 delta and the other was 4-5 delta exotropia. The tropic status was stable, and in two patients who had manifest latent nystagmus, the amplitude of nystagmus was markedly decreased. Head turn was present in all patients before surgery. After surgery head turn was disappeared in five patients but still remained in one although their tropic status changed to orthophoria and the visual acuities of both eyes were equal.

Surgical Effect of Type I Nystagmus Blockage Syndrome

Six patients of nystagmus blockage syndrome (type 1) underwent both medial rectus recession and posterior fixation suture. Associated amblyopia wsa treated with occlusion or atropinization before and after surgery. During follow-up period for 12 weeks (4-36 weeks), four patients revealed orthophoria and one was esotropi a less than 5 delta and the other was 4-5 delta exotropia. The tropic status was stable, and in two patients who had manifest latent nystagmus, the amplitude of nystagmus was markedly decreased. Head turn was present in all patients before surgery. After surgery head turn was disappeared in five patients but still remained in one although their tropic status changed to orthophoria and the visual acuities of both eyes were equal.

Histopathological Study of Extraocular Musele followinr Posterior Fixation Suture in Rabbits: Pathogenesis of Musele Fibrosis

The authors observed the histological and ultrastructural findings in a study of the fibrosis of the extraocular muscles following a posterior fixation suture in rabbits. the early findings demonstrated hyalinosis, clumping of the nuclei of muscle cells and collagenization of the muscle tissue. However, there was no evidence of collagen tissue in the degenerated muscle fiber, reserving cell membrane and basement membrane ultrastructurally. The late findings showed splitting and irregular stain of the muscle fibers, many nuclei of presumed muscle cell and filamentous structure at the collagen tissue in the extracellular space. Electron microscopic study showed atrophy and angulation with distortion of the myofibrillar matrix, along with other cytoplasmic degenerative phe nomena in the muscle fibers. Clumps of the well-arranged microfibrils(Mf) and irregularly arranged Mf with fine granular materials(FGM) were adjacent to the immature collagen fibrils. Many of the Mf and FGM were closely associated, and the number of the Mf and FGM decreased with the degree of maturity of the collagen fibrils. The anatomical structure of the myofibrill was identified as that of the Mf. From these findings, it would appear that formation of collagen fiber occurs in the extracellular space and that Mf and FGM are primarily responsible for the formation of the collagen fibils.