一期植入带活动连接杆（MCP）的多孔聚乙烯眶内植体

眼球摘除术后放置与多孔眶内植入物和义眼一体化活动性连接杆（MCP）可提高义眼的活动度。以前,MCP植入通常需在眼球摘除术6个月后行二期手术。我们发明了一种在眼球摘除术的同时,将MCP可靠、安全地植入到眶内植入物的技术。合格的标准包括获得最大程度的义眼活动度,足够的结膜以确保所需的创口关闭,并分离出4条直肌。用标准的方式行眼球摘除术,同时行圆锥形多孔聚乙烯眶内植入物植入术。植入的MCPs向前突出2－4mm,在突出的MCP表现分层缝合Tenon囊和结膜。对32例患者行一期植入,随访1－33个月（平均15个月）。在开始的4个月内有9例MCPs自发性地暴露,1例MCP在12个月时自行暴露,3例患者行二次手术以暴露连接杆。无1例感染、取出或发生可见的MCP移位。小的并发症有化脓性肉芽肿（2例）和结膜过长（1例）。所有患者都成功地配戴了合适的义眼。义眼的活动度被所有患者接受。在眼球摘除术的同时植入活动性连接杆对经选择的患者是一项有效的可选手术。     

多孔聚乙烯义眼台植入术矫正眼窝凹陷畸形

目的探讨多孔聚乙烯义眼台植入术对眼窝凹陷畸形的手术方法和临床效果。方法对28例无眼球或眼球萎缩者,行高密度多孔聚乙烯义眼台植入术,随访6月~4年。结果28例眼窝凹陷畸形均得以矫正,无义眼台脱出、移位或感染等并发症发生。配戴仿真义眼后,双眼对称,义眼活动度10°~20°。结论多孔聚乙烯义眼台植入术治疗眼窝凹陷畸形临床效果良好,多孔聚乙烯义眼台是治疗眼窝凹陷畸形的良好材料。     

羟基磷灰石义眼座眶内植入139例分析

目的探讨带预置缝线的羟基磷灰石(hydroxyapatite，HA)义眼座直接植入眶内的手术效果。方法自1997年9月～2002年6月进行带预置缝线的HA义眼座直接植入眶内手术139例(139眼)，其中Ⅰ期眶内义眼座植入117眼，Ⅱ期眶内义眼座植入22眼。随访6～24月，平均11．8月。结果139眼术后出现轻微眼睑及球结膜水肿，4眼结膜切口裂开，经保守治疗自愈。2眼HA义眼座暴露，经修复后愈合。随访观察139眼义眼活动良好，眼窝饱满；Ⅰ期较Ⅱ期植入的义眼活动度大，外观更逼真。未发生义眼座脱出及感染等并发症。结论眼球摘除术后植入HA义眼座，提高了眼球运动效果和面部美观程度，效果较好。     

眼球摘除术72例病因及眶内植入物的疗效分析

眼球或眼内容摘除术后同期或Ⅱ期植入填充物可矫正眼窝塌陷,弥补病人的美容缺陷。我们于1994年5月至1999年12月在72例眼球或眼内容摘除的46例中行各种不同类型的植入物植入术,取得了较好的疗效。     

眶内植入带线羟基磷灰石义眼座的临床分析

目的 探讨眶内植入带线羟基磷灰石（HA）义眼座的临床效果。方法 对85例（85眼）眼球摘除者眶内植入带线HA义眼座。结果 术后随访12-36个月,平均18个月。义眼座活动度良好。82例结膜创口Ⅰ期愈合,2例结膜变薄,1例结膜创口裂开,义眼座暴露。无眶内血肿或感染等并发症。结论 眶内植入带线HA义眼座手术操作简单,术后并发症少,美容效果佳,临床效果好。     

眶内植入羟基磷灰石义眼座的术式

羟基磷灰石(hydroxyapatite,HA)义眼台植入术,现已成为临床上广泛采用的眼球摘除或眼内容物剜除术后的主要手术方法,HA义眼台植入的并发症有结膜裂开、感染、义眼台暴露、排斥等,因此义眼台的选择,手术的方式,术后的处理至关重要,我们就手术的方式进行综述。     

人类眶底植入物多孔聚乙烯的纤维血管化

多孔聚乙烯(Medpor，Porex Surgical Inc，Newman，Ga)眶内植入物以其片状、块状或球体的形式作为体积补充物逐渐广泛应用于眼窝凹陷及眶壁骨折修复中。人工合成的聚乙烯眶内植入物比天然珊瑚植入物便宜并且也具有生物相容性、无毒性及孔和管道内相互通连。     

国产羟基磷灰石眼座眶内植入的临床探讨

目的：探讨国产羟基磷灰石眼座在眼球摘除术后眶内植入的效果。方法：将人工合成的羟基磷灰石眼座植入眼窝内，前面用自体巩膜或不用巩膜覆盖。共实施手术66例。结果：随访6月－6．5年，义眼活动自如，未见排异或感染现象，外观改善，患者满意。结论：国产羟磷灰石可为眼窝整形术良好的选用材料。     

Cyst Formation Associated with Porous Polyethylene Orbital Floor Implant

A 28-year-old female presented with hyperglobus and inferior scleral show after the repair of an orbital floor fracture using a porous polyethylene (Medpor) implant. CT revealed a large inferior orbital cystic mass displacing the globe. The cyst was explored and excised and the implant was found to be free from any attachment to surrounding tissues and hence, removed without difficulty. The reason for the cyst development was most likely inadvertent epithelial inclusion at the time of surgery-a recognized risk with insertion of any foreign body via transconjunctival approach. Porous implants when placed in the subperiosteal space might not get incorporated with surrounding tissues and therefore behave like any traditional nonporous alloplastic material.     

Effect of stem cells and fibrin concentration on the vascularization of the Medpor orbital implant

Background: To determine the effect of adipose‐derived adult stem cells (ADASCs) and optimal concentration of fibrin on fibrovascular ingrowth into porous polyethylene orbital implants (Medpor). Methods: Medpor sheet treated with O.25% fibrin only and ADASCs in mixtures containing fibrin (0.25%, 0.5% or 1.25%) were applied to a Medpor sheet and implanted in the back of each of 20 athymic nude mice. After 10 days, implants were removed and observed for fibrovascularization and stability. Haemoglobin, collagen and cellular DNA content were determined in quantitative assays. Results: Haemoglobin, collagen and cellular DNA levels were significantly higher in ADASC group than in the cell‐free implant (0.25% fibrin only) group (P < 0.01). The level of haemoglobin and collagen content was significantly higher in the ADASC + 0.5% fibrin group among the ADASC and fibrin mixtures (P < 0.01). Conclusion: ADASCs significantly improved fibrovascularization on Medpor compared with implants alone. Fibrin, used together with ADASCs to potentiate fibrovascularization, was most effective at concentrations of 0.5%.     

Porous Orbital Implant Exposure: The Influence of Surgical Technique

Abstract

Objectives: To examine orbital implant exposure rates following enucleation and evisceration.

Methods: A retrospective chart review of all patients who underwent an evisceration or enucleation in a single centre over a 5-year period was performed. The indication for surgery, the type and size of orbital implant used, details of the surgical technique adopted and the postoperative complications observed, in particular orbital implant exposure, were recorded.

Results: Over a 5-year period 24 patients had enucleation and 14 had evisceration; 22 of these procedures were performed by an ophthalmic surgeon with a special interest in orbit and oculoplastics while the remaining 16 procedures were performed by 5 ophthalmic surgeons with other sub-specialty interests. Orbital implant exposure occurred in 8 cases. One case had been performed by the first of these surgeons described. Implant exposure occurred in 4% of cases performed by this surgeon. The remaining 7 cases had been performed by the group of surgeons with sub-specialty interests outside of orbit and oculoplastics. Implant exposure occurred in 48% of cases performed by this group.

Conclusions: Orbital implant exposure remains a significant cause of morbidity in patients undergoing enucleation and evisceration. Rates of orbital implant exposure were significantly lower when surgery was performed by an orbital surgeon. Differences in surgical technique are the most likely explanation.     

The Quasi-Integrated Porous Polyethylene Implant in Pediatric Patients Enucleated for Retinoblastoma

Purpose: To describe the clinical outcomes of patients receiving a quasi-integrated porous polyethylene orbital implant following enucleation for retinoblastoma. Methods: A retrospective review of all retinoblastoma patients who received the quasi-integrated porous polyethylene implant following enucleation during the 56-month period between October 2000 and May 2005 was conducted. Results: Ten patients were identified who received the quasi-integrated porous polyethylene implant as a buried, primary orbital implant. Approximately 6 weeks following implantation, a custom-fitted prosthesis was made by an impression technique to provide a “lock-and-key” fit with the orbital implant in the majority of patients. Follow-up ranged from 2 months to 78.5 months following surgery, with an average of 36 months. One case of implant exposure was noted, with no other significant complications. Good motility of the prosthesis was noted in all cases. Conclusions: The quasi-integrated porous polyethylene orbital implant is safe to implant and provides good prosthetic motility without the need for pegs or screws. It was associated with an exposure rate similar to other commonly used implants following enucleation in retinoblastoma cases.     

The porous polyethylene (Medpor) spherical orbital implant: a retrospective study of 136 cases

PURPOSE: To evaluate complications and risk factors associated with the placement of wrapped and unwrapped porous polyethylene (PP) spherical implants after evisceration, enucleation, or secondary implantation. METHODS: A retrospective, interventional, noncomparative case series of consecutive cases of PP implant placement after anophthalmic socket surgery performed by three surgeons over a 5-year period. A PP spherical implant was placed in 133 patients, 61 women (2 bilaterally) and 72 men (1 bilaterally). There were 91 enucleations, 30 eviscerations, and 15 secondary implant placements. Sixty-six (48.5%) implants were wrapped prior to placement. Parameters evaluated included: age, sex, prior ocular surgery or radiation treatment, indications for surgery, procedure performed, size of PP sphere, material used to wrap the implant, and complications. RESULTS: A total of 17 of 136 (12.5%) cases had documented postoperative complications, with implant exposure being the most common. In 5 patients (3.7%), implant exposure developed: 1 after evisceration and 4 after primary enucleation. Three of the five exposures were small and resolved with either observation alone or in one case with surgical revision of the socket. In two cases, the exposures were large enough that removal of the implant was indicated, one after evisceration and the other after enucleation with placement of a wrapped PP sphere. CONCLUSIONS: Our series revealed no significant difference in exposure rate between wrapped and unwrapped PP sphere implants, nor was the exposure rate affected by whether an eye was eviscerated or enucleated.     

改良眼内容摘除义眼台植入术效果分析

目的 探讨改良眼内容摘除义眼台植入术的临床效果和安全性.方法 回顾分析30例改良眼内容摘除义眼台植入术,对其效果进行观察.结果 手术30例,无一例义眼台暴露,无眶区凹陷发生,眶区饱满度理想,薄壳义眼可活动,但较正常眼略差.结论 改良眼内容摘出义眼台植入明显降低了义眼台的暴露率,且不会发生义眼台下坠等情况,取得更好的外观效果.     

Orbital schwannoma: histopathologic correlation with magnetic resonance imaging

CASE REPORT: A 45-year-old man presented with an orbital tumour that on MRI was most consistent with a hemangioma. Histopathologic examination disclosed an orbital schwannoma, with cystic and mucinous degeneration complicating radiologic interpretation. COMMENTS: An array of ancillary studies including orbital ultrasonography may be useful in substantiating the diagnosis preoperatively.     

Intraocular lens implants (pseudophakoi) and steelwire sutures: a contraindication for MRI?

The strong magnetic field of the super-conducting MRI (Magnetic Resonance Imaging) apparatus could cause problems in the presence of metallic foreign material, such as the metal clips and loops of intraocular lenses and steel as suturing material. If the magnetic field were to induce movement this could be dangerous for the eye. In this study these materials were tested with the 0.5 Tesla MRI and a 1.0 Tesla permanent magnet. Intraocular lenses with a platinum clip, or metallic or plastic loops, and 5 × 0/6 × 0 steelwire used as suturing material experienced no magnetic movement or change of position in the strong magnetic field. Neither did these foreign materials have any effect on the images obtained (spin-echo pulse sequence, 0.5 T Gyroscan). No artefacts were produced, the normal MRI picture of the T₁ -T₂ calculated images, made with a special deticated eye surface coil, were obtained.     

The Role of Eye Movements During Reading in Patients with Age-Related Macular Degeneration (AMD)

AMD patients often have particular difficulty reading, even when the text is magnified to compensate for reduced visual acuity. This study explores whether reading performance can be explained by eye movement factors. Forty patients with advanced AMD were tested with a high-speed video eye tracker to evaluate fixation stability and saccadic eye movements. Reading speed was measured for standardized texts viewed at the critical print size. Visual acuity and contrast sensitivity were unrelated to reading speed, but fixation stability, proportion of regressive saccades and size of forward saccades were all significantly associated with reading performance, accounting for 74% of the variance. The implications of these findings for low-vision training programmes are discussed.