Ultrastructural changes of myotendinous nerve endings following recession or resection procedures of extraocular muscle surgeries in cats

To verify the postoperative ultrastructural changes of the myotendinous nerve endings of feline extraocular muscles, which are known as proprioceptors. Sixteen recti of four cats were used and divided into three groups. In group A, eight lateral recti were recessed. In group B, four medial recti were resected by 10 mm from insertion to include the myotendinous junction. In group C, four medial recti were resected by 4 mm of muscle bellies only, without disturbing the myotendinous junction. Four weeks after surgery, specimens were examined with electron microscopy. In group A, overall neural structures were well maintained with slight axonal degeneration. In group B, only muscle fibers were observed without any regeneration of neural sprouts. In group C, axonal disintegration and shrinkage were evident. These results indicate that myotendinous nerve endings can be damaged in strabismus surgery, and that resection was more invasive than recession in disrupting myotendinous nerve endings.     

Suturing technique for extraocular muscle surgery.

A method for suturing extraocular muscles is presented which provides a safe, anatomically perfect means of reattaching extraocular muscles after recession, resection, or after disinsertion at retinal surgery.     

The oculocardiac reflex as a surgical aid in identifying a slipped or ''lost'' extraocular muscle.

The oculocardiac reflex during strabismus surgery has generally been regarded as a hazard capable of causing death. Six cases are presented which show a beneficial use of the oculocardiac reflex. Isolation of a previously slipped or 'lost' extraocular muscle can be difficult. In this series identification of the tissue as muscle was substantiated by observing a positive oculocardiac reflex when traction was placed on the suspected tissue. Each of the 6 dislodged extraocular muscles was the medial rectus muscle. Three of the muscles had been resected and 3 either recessed or tenotomised. In one patient, despite 6 previous strabismus operations, including 2 strabotomies on a muscle that slipped, and in another patient, who had a lapse of 6 years since the last strabotomy, when the slipped muscle was isolated, the oculocardiac reflex could still be elicited. To avoid abolishing the oculocardiac reflex during surgery the anaesthetist should be instructed to avoid the use of an intravenous parasympatholytic agent, such as atropine, at the time of induction and during the operation.     

Adjustable sutures: experimental assessment of final muscle position

The likelihood of forward "creep" of muscles recessed with the use of adjustable loops of suture in the correction of strabismus was investigated. Twelve orthotropic dogs underwent both regular and loop recessions of the lateral and medial rectus muscles; the data for two of the dogs were excluded because of loss of muscles. Three months later it was found that in the majority of cases the recessed muscles had minimally advanced from the position of surgical placement. Although the type of recession made little difference to the results, the mean forward creep was much greater for the medial rectus muscles (1.55 +/- 0.68 mm [p less than 0.01] and 2.00 +/- 2.44 mm [p = 0.09] for those undergoing regular and loop recessions respectively) than for the lateral rectus muscles (0.35 +/- 0.58 mm and 0.60 +/- 0.62 mm respectively). During the operations the amount of contraction of the medial rectus muscle had been noted to vary. It is likely that in some instances the tension on the suture loops was insufficient to hold them taut, and the muscles therefore adhered to the sclera at variable sites. Hence, adequate intrinsic muscle tone may be important for predictable clinical results of loop recession.     

大角度外斜视手术方法的对比分析

目的探讨大角度外斜视行外直肌悬吊后徙术与外直肌超常量后徙术的比较,观察手术效果。方法两组病例共42例,手术前后均采用角膜映光法、三棱镜遮盖试验测定眼位。一组实施外直肌悬吊后徙术,另一组则行外直肌超常量后徙术。结果两组术前斜视角大小无显著性差异。术后眼位:外直肌悬吊后徙组≤±10~Δ18例,正位率85.71%;外直肌超常量后徙组≤±10~Δ19例,正位率90.48%,两组正位率比较差异无显著性。结论采用外直肌悬吊后徙术矫正大角度外斜视,既可以达到外直肌超常量后徙术的效果,又降低了巩膜意外损伤的危险,具有合理、实用、安全、简便等特点。     

Restrictive horizontal strabismus following blepharoplasty

PURPOSE: To report a case of horizontal diplopia after a four-lid blepharoplasty. DESIGN: Observational and interventional case report. METHODS: Analysis of the history and management of a 64-year-old man who underwent a four-lid blepharoplasty, after which he developed horizontal diplopia. RESULTS: The patient was found to have a restrictive esotropia. He underwent a recession of the left medial rectus on an adjustable suture, with recurrence of the same pattern of diplopia one month after surgery. CONCLUSIONS: The involvement of the extraocular muscles as a complication of blepharoplasty is uncommon, but when it is present, it may be very difficult to treat.     

Fibrin gluing of the extraocular eye muscles. Experimental use in the rabbit

An experimental animal study was conducted to determine whether fibrin glue could be used in strabismus surgery (recession, resection, and muscular neurotization). Fibrin glue was used in place of some or all of the commonly used 7-0 Vicryl sutures. In order to evaluate the adhesion of the fibrin glue the rabbits' eyes were enucleated 10-67 days after surgery, fixed in 8% formalin solution and then histologically examined. In the recession and resection specimens a solid joint between muscles and sclera was found, without any significant scar formation or atrophy of the muscles. The muscular neurotization specimens also exhibited a firm connection between the two muscles, with no abnormal loss of muscle fibers by cicatrization or atrophy. In none of the cases did the conjunctiva show any tendency to conglutination. In view of the simplicity of the fibrin gluing technique and the uniform bonding effect, application in human patients is recommended.     

Expression of four growth factors in recessed extraocular muscles of rabbits.

BACKGROUND AND OBJECTIVE: The study was designed to determine the temporal expression of insulin-like growth factor (IGF)-I, IGF-II, basic fibroblast factor 2 (bFGF-2), and transforming growth factor beta 1 (TGF-beta1) in recessed extraocular muscles. MATERIALS AND METHODS: Sixteen eyes of eight rabbits were subjected to conventional 4-mm recession of superior rectus muscles. Two rabbits were untreated as control. The rabbits were killed and their eyes were enucleated at 3 (group 3), 6 (group 6), 24 (group 24), and 72 (group 72) hours after the operation (two rabbits per group), and the expression of IGF-I, IGF-II, bFGF-2, and TGF-beta1 was immunohistochemically examined. RESULTS: The peak levels of IGF-I, IGF-II, and TGF-beta1 expression were observed in groups 24, 6, and 3, respectively. However, bFGF-2 was less expressed than the other growth factors in all groups. CONCLUSIONS: IGF-I, IGF-II, bFGF-2, and TGF-beta1 in regenerating muscle cells were expressed by different kinetics, suggesting a distinct role of each growth factor during wound healing after recession of extraocular muscles.     

垂直斜视术后屈光状态的动态分析

目的了解斜视术后眼球屈光状态的动态变化及不同术式对屈光状态的影响,并对其发生机理进行初步探讨。方法用散瞳验光和角膜地形图检查,对35例垂直斜视进行手术前后屈光状态的动态分析。结果斜肌手术对眼球屈光状态无影响,上直肌后徙术可使上方角膜变陡峭,但对鼻、下、颞侧角膜及散光度无影响。上直肌后徙术及下直肌截除术对上、下侧角膜及散光度的影响有显著性差异(P<0．01)。结论斜视手术对眼球屈光状态的影响是可恢复的,不同术式所需恢复的时间不同。     

甲状腺相关眼病行眼外肌后徙松解术的疗效观察

目的探讨甲状腺相关眼病（TAO）致限制性斜视患者眼外肌后徙松解术后,视力、眼压、视野、视网膜中央动脉血流速度的变化。方法选择2002年1月至2004年1月于北京协和医院眼科诊治的17例（20只眼）因TAO致限制性斜视行手术治疗的患者,其中1例行上直肌断腱术、1例行上直肌悬吊术、1例行右下直肌后徙联合左上直肌后徙术,余14例（17只眼）行下直肌后徙术。20只患眼手术前、后均检查视力、眼压、视野,测量视网膜中央动脉血流速度,并进行对照比较。结果术后5只眼视力提高≥2行,15只眼维持术前视力;术前、后眼压和视野平均缺损情况比较,差异有统计学意义（P〈0．01）;术前、后视网膜中央动脉血流参数比较：术后收缩期峰值血流速度（PSV）、舒张末期血流速度（EDV）增加及阻力指数（RI）降低（P〈0．05）。结论TAO致限制性斜视患者于静止期行眼外肌后徙松解术治疗,不仅可消除复视,使眼球运动好转,而且能提高裸眼视力、缓解眼压、改善视野和视网膜中央动脉血流速度。（中华眼科杂志,2005,41：772—776）