Coralline hydroxyapatite orbital implant (bio-eye): experience with 158 patients

PURPOSE: To assess the problems seen in 158 patients with coralline hydroxyapatite (HA) orbital implants (Bio-Eye). METHODS: A consecutive case series of 170 patients receiving coralline HA implanted by two surgeons over a 5-year period were reviewed. The authors analyzed age, type of surgery, implant size, peg system, follow-up duration, time of pegging, problems encountered, and treatment. RESULTS: Twelve patients were lost to follow-up after 5 months, leaving 158 patients who were followed from 6 to 130 months (average, 39 months). Problems in unpegged implants occurred in 36 (22.8%) patients. Discharge occurred in 18 (11.4%) patients, implant exposure in 12 (7.6%), socket discomfort in 1 (0.6%), conjunctival thinning in 3 (1.9%), chronic conjunctival swelling in 2 (1.3%), and implant infection in 3 (1.9%). Problems after pegging occurred in 68 (50.7%) of 134 patients: discharge in 27 (20.1%), pyogenic granuloma in 24 (17.9%), conjunctiva overgrowing the peg in 4 (3.0%), implant exposure around the sleeve in 5 (3.7%), clicking in 6 (4.5%), peg on an angle in 2 (1.5%), loose sleeve in 1 (0.7%), peg falling out in 18 (13.4%), popping peg in 1 (0.7%), poor transfer of movement in 3 (2.2%), pain with movement in 1 (0.7%), and implant infection in 2 (1.5%). CONCLUSIONS: The Bio-Eye orbital implant represents a porous orbital implant that is biocompatible with orbital tissues and allows fibrovascular ingrowth and improved motility when coupled to the overlying artificial eye. It is more expensive than other commercially available porous orbital implants, such as synthetic FCI3 HA, porous polyethylene (Medpor), and aluminum oxide (Bioceramic) implant. Problems encountered with its use are similar to those problems seen in patients with the synthetic FCI3 hydroxyapatite and aluminum oxide orbital implants.     

Problems after evisceration surgery with porous orbital implants: experience with 86 patients

PURPOSE: To assess the problems associated with the use of 4 types of porous orbital implant (Bio-Eye coralline hydroxyapatite, FCI3 synthetic hydroxyapatite, aluminium oxide [Bioceramic], and porous polyethylene [Medpor]) after evisceration surgery. METHODS: A retrospective analysis was made of all cases of evisceration with placement of one of four types of porous orbital implants performed between 1991 and 2002 by one surgeon (n = 86). Patient age, implant type and size, surgery type (standard evisceration or evisceration with posterior sclerotomies), peg system used, follow-up duration, time of pegging, problems before and after pegging, and treatment were recorded. RESULTS: Eight patients had less than 6 months of follow-up. The other 78 patients were followed for 6 to 107 months (average, 31 months). The following problems were noted before peg placement: discharge, 8 patients (10.2%); implant exposure, 6 patients (7.7%); implant fracture at the time of surgery, 1 patient (1.3%); persistent pain, 1 patient (1.3%). Of the 29 patients who had pegging, problems including discharge, exposure, pyogenic granuloma, infection, and peg sleeve problems occurred in 23 (79.3%). Sixteen (55.2%) of the 29 patients required at least 1 additional surgical procedure, 4 required 3 additional procedures, and 2 required 5 additional procedures, including implant removal. CONCLUSIONS: Although primary evisceration with posterior sclerotomies and placement of a porous orbital implant is an accepted technique for treating a variety of end-stage eye diseases, patients should be cautioned about an increased likelihood of problems and potential need for additional surgeries if pegging is considered.     

The bioceramic orbital implant: experience with 107 implants

PURPOSE: To assess the problems associated with the Bioceramic (Aluminum oxide, Al(2)O(3)) orbital implant. METHODS: A consecutive case series of 107 patients receiving a Bioceramic orbital implant by two surgeons over a 3-year period were reviewed. The authors analyzed patient age, type of surgery, size of implant, peg system, follow-up duration, time of pegging, complications encountered, and treatment. RESULTS: Seven patients were lost to follow-up after 2 months, leaving 100 patients who were followed from 3 to 38 months (average, 13.4 months). Three patients died during the follow-up period (one with 2 months' follow-up, one with 7 months' follow-up, and the third with 9 months' follow-up). Implant-related problems occurred in 11 (11%) patients. Discharge occurred in 5 (5%) patients, implant exposure in 2 (2%), socket discomfort in 1 (1%), trochleitis in 1 (1%), and conjunctival thinning in 2 (2%). Peg problems occurred in 11 (34.3%) of 32 pegged patients: discharge in 4 (12.5%) and in 1 patient (3.1%) each, pyogenic granuloma, conjunctiva overgrowing the peg, implant exposure around the sleeve, clicking, accumulation of black material, and broken peg during insertion. Infection did not occur in any patient. CONCLUSIONS: The Bioceramic orbital implant represents an alternative porous orbital implant that is biocompatible with orbital tissues, easy to manufacture, structurally strong, and less expensive than other commercially available porous orbital implants (e.g., Bio-Eye hydroxyapatite implant). Problems encountered with its use are similar to those seen with the Bio-Eye orbital implants but appear to occur less often. The incidence of exposure associated with the Bioceramic implant is less than that reported for the Bio-Eye.     

The use of vicryl mesh in 200 porous orbital implants: a technique with few exposures

PURPOSE: To report the results of a wrapping technique for porous orbital implants by using polyglactin 910 (Vicryl) mesh (Ethicon Inc., Somerville, NJ, U.S.A.). METHODS: We retrospectively reviewed the records of 200 consecutive patients from one author's practice who received a polyglactin 910 mesh-wrapped porous orbital implant after enucleation or as a secondary implant between October 1, 1996, and April 15, 2001. We recorded potential problems that might be attributed to polyglactin 910 mesh both before pegging (excessive inflammatory response to the material, conjunctival thinning, and implant exposure) and after pegging (exposure of the implant around the sleeve, conjunctival thinning, and implant exposure other than adjacent to the peg). RESULTS: One hundred twenty-two men and 78 women underwent placement of a polyglactin 910 mesh-wrapped porous orbital implant. The average age at the time of implantation was 48.9 years (range, 11 to 85 years). The average follow-up interval in the 200 patients was 19.4 months (range, 2 to 80 months). Thirteen of the 200 patients had less than 6 months of follow-up, leaving 187 patients with an average follow-up of 20.5 months (range, 6 to 80 months). There were 76 primary enucleations and 124 secondary orbital implants. Thirty-seven patients received a Bio-Eye hydroxyapatite implant (HA) (Integrated Orbital Implants, San Diego, Calif), 97 received a synthetic FCI hydroxyapatite implant (FCI, Issy-Les-Moulineaux, France), and 66 received a Bioceramic implant (aluminum oxide-Al2O3) (FCI, Issy-Les-Moulineaux, France). One hundred fourteen patients (57%) underwent peg placement. The average time to pegging was 9.9 months (range, 6 to 16 months). Before pegging, 4 of 187 patients (2.1%) had implant exposure. Three of these exposures followed secondary orbital implant placement (2 Bio-Eye HA, 1 synthetic FCI3 HA) and one followed an enucleation (synthetic FCI3 HA). Two patients required a temporalis fascia graft and one required a scleral patch; the remaining defect closed spontaneously. One patient had conjunctival thinning 6 months after orbital implantation, which remained stable with no frank exposure for 36 months. No patient had excess socket inflammation. After peg placement, 3 additional patients had exposure of the implant around the peg site. There were no cases of conjunctival thinning or exposure of the implant other than adjacent to the peg site. CONCLUSIONS: Polyglactin 910 mesh is an excellent option as a wrapping material for porous orbital implants. It is simple to use, readily available, eliminates the need for donor tissue, does not require a second operative site, and it is less expensive than other currently available wrapping materials. We attribute our high success rate to our technique, which emphasizes proper placement of the implant within the Tenon space, suturing the extraocular muscles anterior to their normal anatomic sites, and meticulous closure of the Tenon capsule and conjunctiva in separate layers.     

Complications associated with pegging hydroxyapatite orbital implants

OBJECTIVE: Prior studies of hydroxyapatite orbital implant complications have primarily focused on complications of the implant itself with only occasional mention of the complications associated with the peg system. This in part may be because of a low rate of pegging and, thus, a small sample size to evaluate. Therefore, a full range of complications that can occur with pegging has not been presented. The objective of this study was to determine the complications associated with pegging and to discuss ways to manage them. DESIGN: Retrospective, noncomparative case series. PARTICIPANTS/INTERVENTION: The authors analyzed all of the complications associated with pegging 165 of a possible 275 hydroxyapatite implants implanted by 2 surgeons over 7 years. MAIN OUTCOME MEASURES: The following data were recorded: type of surgery performed, size of implant used, type of hydroxyapatite used, peg system used, time of pegging, follow-up duration, problems encountered, and treatment. RESULTS: Sixty-two (37.5%) of the 165 patients who had pegged implants were found to have problems with their pegs. Twenty-one (33.8%) of the 62 patients with peg problems had more than 1 peg-related problem. Complications associated with pegging included discharge (37%; 23 of 62), pyogenic granulomas (30.6%; 19 of 62), peg falling out (29%; 18 of 62), poor transfer of movement (11.2%; 7 of 62), clicking (11.2%; 7 of 62), conjunctiva overgrowing peg (4.8%; 3 of 62), poor-fitting sleeve (4.8%; 3 of 62), part of sleeve shaft visible (4.8%; 3 of 62), peg drilled on an angle (4.8%; 3 of 62), hydroxyapatite visible around peg hole (3.2%; 2 of 62), peg drilled off-center (3.2%; 2 of 62), popping peg (3.2%; 2 of 62), and excess movement of peg (3.2%; 2 of 62). The most serious complication occurring in two individuals (3.2%) was implant infection requiring implant removal. CONCLUSION: There are several potential complications that can occur after pegging the hydroxyapatite implant. These problems are generally of a minor nature but often require additional patient visits that would not ordinarily have been required if the peg was not in place. The most serious peg problem is implant infection, which may necessitate implant removal. These potential peg problems should be reviewed with the patient before the procedure is performed.     

Complications of motility peg placement for porous hydroxyapatite orbital implants

AIM: To evaluate the complications associated with pegging of porous hydroxyapatite orbital implants. METHODS: Complications associated with pegging were retrospectively reviewed from the charts of 100 of 133 patients with hydroxyapatite implantation from 1993 to 2000. RESULTS: 48 (48%) of the 100 hydroxyapatite implanted patients who had undergone pegging were found to have problems with their pegs, including discharge (45.8%), peg falling out (20.8%), pyogenic granulomas (16.7%), popping peg (14.6%), hydroxyapatite visible around peg hole (8.3%), part of peg shaft visible (6.2%), peg drilled off centre (6.2%), peg drilled at an angle (4.2%), and excess movement of peg (4.2%). The standard peg fell out statistically more often than the peg and sleeve system (Yates's corrected chi(2), p=0.038). There was a trend towards complications of the peg with use of a standard peg (versus sleeved peg) (p=0.226). CONCLUSIONS: There are several potential complications of pegging. Most complications are minor and can be managed successfully.     

义眼台植入术后脓性肉芽肿形成原因的探讨

目的探讨珊瑚多孔羟基磷灰石义眼台植入术后脓性肉芽肿形成的原因。方法回顾性分析我院羟基磷灰石义眼台植入250例,及外院手术者1例,共251例(251眼),对其中发生脓性肉芽肿的病例、分析其发生的原因。随诊4月~9年。结果251例中发生脓性肉芽肿4例(包括外院1例),其中1例脓性肉芽肿形成时,义眼台尚未钻孔,3例在钻孔及栓钉置入术4~7年后脓性肉芽肿形成。4例保守治疗效果欠佳,3例最终行义眼台取出术,1例拒绝手术。结论脓性肉芽肿形成是羟基磷灰石义眼台眶内植入较少见的并发症,发生原因与义眼台暴露,义眼台血管纤维化不足,义眼台钻孔及栓钉置入等有关。脓性肉芽肿的形成预示义眼台发生了感染,致病菌以厌氧性革兰氏染色阳性球菌为主。义眼台取出术是治疗的关键。     

A new titanium peg system for hydroxyapatite orbital implants

PURPOSE: To evaluate a new hydroxyapatite-coated titanium sleeve and titanium peg system for HA orbital implants. METHODS: The authors followed 54 patients receiving an HA-coated titanium sleeve and peg system and analyzed the complications associated with this peg system. The following data were recorded: type of surgery performed, size of implant used, type of HA used, time of pegging, follow-up duration, problems encountered, and treatment. RESULTS: Fifty-seven patients received the HA-coated titanium peg and sleeve system. The average duration of follow-up was 15 months (range, 3-30 months). Three patients were lost to follow-up after 1 month. Complications associated with peg placement in 54 patients included: discharge (9.2%), pyogenic granulomas (14.8%), peg falling out during prosthesis removal (9.2%), poor transfer of movement (1.8%), clicking (3.7%), conjunctiva overgrowing peg (1.8%), part of sleeve shaft visible (9.2%), peg drilled on an angle (1.8%), HA visible around peg hole (3.7%), and loose sleeve (3.7%). CONCLUSION: The HA-coated titanium sleeve and titanium peg is a new peg system available for HA orbital implants. Many of the complications associated with this peg system are similar to the commonly used polycarbonate peg system. Pyogenic granulomas and discharge, however, appear to be less frequently encountered with this new system. The HA-coated titanium sleeve and titanium pegs were well tolerated and appeared quieter in the socket than most polycarbonate pegs.     

羟基磷灰石义眼台眶内植入术后结膜脓性肉芽肿形成的原因分析(英文)

目的:分析羟基磷灰石(hydroxyapatite,HA)义眼台眶内植入术后结膜脓性肉芽肿形成的原因。方法:回顾性分析我院眶内植入HA义眼台250例(钻孔及栓钉置入68例),随诊18mo~10a,脓性肉芽肿形成后首先药物保守治疗,无效后采用手术治疗。结果:植入HA义眼台250例中发生脓性肉芽肿10例,其中9例在钻孔及栓钉置入术4~7a后发生,1例发生时羟基磷灰石义眼台未钻孔。9例保守治疗效果均欠佳,行HA义眼台取出术,1例拒绝眼台取出而继续保守治疗。结论:脓性肉芽肿是严重的义眼台植入术后并发症,发生原因可能与义眼台植入后血管化不足,义眼台暴露与继发感染,异体材料包被,义眼台钻孔及栓钉置入等因素有关,而与栓钉的材料无关。脓性肉芽肿的发生意味着义眼台可能发生了感染,最终需行义眼台取出术。     

Fibrovascularization of porous polyethylene (Medpor) orbital implant in a rabbit model

PURPOSE: To evaluate the porous polyethylene (Medpor) orbital implant in a rabbit model and compare it with three other currently available porous implants: Bio-Eye coralline hydroxyapatite (HA), FCI(3) synthetic HA, and aluminum oxide (Bioceramic). METHODS: The porous polyethylene implant was examined macroscopically and microscopically (with scanning electron microscopy). Implantation was performed in 10 adult male New Zealand albino rabbits. Each animal underwent enucleation of the right globe under general halothane gas anesthesia, followed by placement of a 12-mm porous polyethylene implant. In 5 animals, the implant was encased in polyglactin 910 (Vicryl mesh); in the other 5, it was left unwrapped. The implants were moistened in saline before placement. Implant vascularization was evaluated by histopathology at 4, 8, 12, 16, and 24 weeks. RESULTS: The porous polyethylene implant was found to have a smoother exterior surface than the Bio-Eye, FCI(3) synthetic HA, and aluminum oxide implants. Rather than a uniform interconnected porous architecture, there was an extensive system of interconnected channels through the implant, ranging in size from 125 to 1000 microm. On high-power examination there was a more solid, woven appearance without any sign of the microcrystals seen in the other porous implants. One rabbit had a retrobulbar hemorrhage after surgery and was euthanized. All the other rabbits tolerated the implant well, and there were no complications. On histopathologic examination, fibrovascularization gradually increased over time. One implant was completely vascularized at 12 weeks, and both implants harvested at 16 weeks were completely vascularized. The implant harvested at 24 weeks showed only partial vascularization (14%). CONCLUSIONS: The porous polyethylene orbital implant represents an alternative implant for use after enucleation or evisceration or for secondary implantation. In our rabbit model, the porous polyethylene implant was well tolerated without complication. Complete fibrovascularization was first seen at 12 weeks. Porous polyethylene orbital implants appear to vascularize more slowly than Bio-Eye coralline HA, FCI(3) synthetic HA, and aluminum oxide implants.     

Current trends in managing the anophthalmic socket after primary enucleation and evisceration

PURPOSE: To evaluate current trends in the management of the anophthalmic socket after primary enucleation and evisceration. METHODS: The active membership of the American Society of Ophthalmic Plastic and Reconstructive Surgery (ASOPRS) was surveyed regarding primary enucleations and eviscerations performed between January and December 2002. Survey questions included practice demographics, orbital implant use, wrapping materials, placement of a motility peg, reasons for implant choice, and complications encountered. RESULTS: A total of 2,779 primary orbital implants were reported, comprising 1,919 (69.1%) enucleations and 860 (30.9%) eviscerations. The high-density porous polyethylene implant was used most frequently for enucleations (42.7%), followed by coralline hydroxyapatite (27.3%) and nonporous alloplastic implants (19.9%). For eviscerations, the high-density porous polyethylene implant was the most commonly used implant (42.3%), followed by hydroxyapatite (25.9%) and nonporous alloplastic implants (25.7%). The top 3 reasons for implant choice were outcome (69.3%), cost (43.6%), and experience (39.5%). Most implants were either not wrapped (59.8%) or were wrapped in donor sclera (25.2%) or polyglactin mesh (7.2%). Pegs were used in 8.1% of all implants reported. The most frequent complications encountered for unpegged implants were exposure (3.2%) and infection (0.4%). For pegged implants, the most common complications reported were pyogenic granuloma (13.7%), exposure (5.7%), and discharge (5.7%). CONCLUSIONS: In managing the anophthalmic socket, ASOPRS survey respondents preferred to use the porous polyethylene implant after primary enucleation and evisceration. Most orbital implants were not wrapped, and most surgeons preferred not to place a motility post or peg in the implant.     

Spontaneous loosening of hydroxyapatite peg sleeves.

OBJECTIVE: To report a new complication associated with pegging hydroxyapatite orbital implants: spontaneous loosening of the sleeve. DESIGN: Retrospective noncomparative case series. PARTICIPANTS: Four patients ranging in age from 38 to 60 years participated. METHODS: Four patients are described who successfully received hydroxyapatite orbital implants with motility peg and sleeve systems. In each case spontaneous loosening of the sleeve developed. MAIN OUTCOME MEASURE: Clinical and surgical outcomes were assessed. RESULTS: Three patients had the peg and sleeve removed followed by repair of the peg hole, and one patient had placement of a larger diameter peg and sleeve system. All patients did well. CONCLUSIONS: Problems have been reported when motility coupling pegs are used with hydroxyapatite orbital implants. Spontaneous loosening of the sleeve is another potential complication to discuss with the patient considering an implant peg.     

Pyogenic granuloma as a presenting sign of hydroxyapatite orbital implant exposure: a clinicopathologic study

PURPOSE: We report 5 unusual cases of exposed hydroxyapatite orbital implants that presented as pyogenic granulomas. We propose pathogenesis and histopathologic correlations. METHODS: A clinicopathologic study of 5 patients with hydroxyapatite implants who presented with pyogenic granuloma. RESULTS: Pyogenic granulomas were detected 1.5 to 30 months after implantation in 5 patients. The lesions were multiple but were not related to the wound margin at the exposed area and were not covered by the surface epithelium in most instances. Exposure defects were detected in all patients at the time of lesion excision. The mean exposure size in the greatest dimension was 16 mm (range, 9-20 mm). Three patients were treated successfully with simple excision of the granulomas, burring down of the anterior surface of the implants, and direct repair of the exposure defects. Explantation of the implant was performed in 2 cases. Histopathologic examination revealed chronic inflammation and microabscess formation in the explanted implants. CONCLUSIONS: Five patients with pyogenic granulomas were found to have hydroxyapatite exposure. Pyogenic granuloma should not be considered a benign lesion on a hydroxyapatite orbital implant, especially in recurrent cases. Ophthalmologists must be aware of the possibility of conjunctival dehiscence with hydroxyapatite-implant exposure beneath the lesion.     

羟基磷灰石义眼座植入Ⅰ期钻孔的初步效果

目的 评价羟基磷灰石义眼座植入Ⅰ期钻孔放置钛钉的疗效。方法 对31例眼球摘除患者行Ⅰ期或Ⅱ期羟基磷灰石义眼座植入同时行钻孔,钻入钛钉的螺纹套子,中间放置平头钉,3～7个月后剪开,更换为球头钉,定制义眼片。结果 随访3．0～11．0个月(平均6．9个月),所有患者对义眼外观及活动度满意,无义眼座暴露、继发感染、栓钉脱出、栓钉偏斜等并发症。结论 羟基磷灰石义眼座植入Ⅰ期钻孔手术效果好,无明显增加并发症的发生机会,是一种可供选择的手术方法。     

Complications of hydroxyapatite pegging: comparison between polycarbonate and titanium peg system

PURPOSE: Polycarbonate peg has been customarily used for pegging of hydroxyapatite for years. For better movement, tissue tolerance, and to decrease the complications of pegging, titanium peg system has been used. This study compares the two systems. METHODS: Complications associated with pegging (polycarbonate: Bio-Eye or titanium: Dr-Perry new P-K) were retrospectively reviewed from the charts of 153 patients admitted to the Labbafinejad Medical Center, Tehran, Iran, for over 5 years from 1997 to 2003. RESULTS: A total of 153 cases were studied. Ninety-six (62.3%) were male and 57 (37.7%) were female, and the mean age was 27.7 years (6-59 years). In 88 cases pegs were poly-carbonate and sleeve system and in 65 cases pegs were titanium. Forty-one (46%) of cases with polycarbonate and 18 (27%) of cases with titanium had at least one or more complications (p=0.018).The most common complications were granulation tissue, discharge, overgrowth of conjunctiva, and peg falling out in 25%, 23%, 13%, and 8% in polycarbonate peg and 15%, 5%, 1.5%, and 0% in titanium peg group. The prevalence of the last three complications was statistically lower in titanium peg compared with polycarbonate. Twenty-five cases (35%) with polycarbonate peg and 5 cases (7.5%) with titanium peg had two or more complications (p=0.03). Peg removal was done in 11 cases of polycarbonate but only two cases of titanium peg in order to treat the complication. CONCLUSIONS: Both pegging systems had some complications, although these were less severe and prevalent in titanium peg. More studies on complications due to titanium pegs are recommended.     

Aspergillus mycetoma in a secondary hydroxyapatite orbital implant: a case report and literature review.

OBJECTIVE: The authors describe the first case report of a fungal abscess within a hydroxyapatite orbital implant in a patient who had undergone straightforward secondary hydroxyapatite implant surgery. DESIGN: Case report and literature review. INTERVENTION: Four months postoperatively after pegging and 17 months after original implant placement, chronic discharge and socket irritation became evident. Recurrent pyogenic granulomas were a problem, but no obvious area of dehiscence was present over the implant. The peg and sleeve were removed 31 months after pegging (44 months after original placement of the implant). The pain and discharge did not resolve, and the entire hydroxyapatite orbital implant was removed 45 months after sleeve placement and 58 months after initial implant placement. The pain and discharge settled rapidly. MAIN OUTCOME MEASURES: Cultures and histopathology. RESULTS: Results of bacterial cultures were negative. Results of histopathologic examination of the implant disclosed intertrabecular spaces with multiple clusters of organisms consistent with Aspergillus. CONCLUSIONS: Persistent orbital discomfort, discharge, and pyogenic granulomas after hydroxyapatite implantation should cause concern regarding potential implant infection. The authors have now shown that this implant infection could be bacterial or fungal in nature. This is essentially a new form of orbital Aspergillus, that of a chronic infection limited to a hydroxyapatite implant.     

Porous polyethylene orbital implant in the pediatric population

PURPOSE: To determine the incidence of complications of primary insertion of porous polyethylene orbital implant in the pediatric population. DESIGN: Interventional case series. METHODS: Prospective nonrandomized case series of 36 eyes of 36 patients under age 15 years who underwent primary placement of an anteriorly wrapped spherical porous polyethylene orbital implant from March 1998 to August 2002, with at least 17 months of follow-up. RESULTS: The mean age at the time of surgery was 4.6 years. The histopathologic diagnoses after enucleation included intraocular tumor in 22 patients, phthisis bulbi in eight patients, microphthalmos in three patients, Coats disease in two patients, and ruptured traumatic globe in one patient. Twelve patients (33%) had prior ocular surgery. At the time of enucleation, all patients underwent primary placement of spherical porous polyethylene orbital implant anteriorly wrapped with homologous sclera in 30 patients (83%) and autologous sclera in six patients (17%). The spherical implant size was 16 mm in one patient (3%), 18 mm in 10 patients ( 28%), and 20 mm in 25 patients (69%). The prosthesis was fitted after a mean interval of 5 weeks. After a mean follow-up of 44 months (range, 17 to 68 months), there was one case of pyogenic granuloma (3%) and one case of implant exposure (3%). There were no cases of implant extrusion, superior sulcus syndrome, orbital cellulitis, or significant inflammatory response. No porous polyethylene orbital implant was drilled for peg placement. CONCLUSIONS: Anteriorly wrapped primary porous polyethylene orbital implant in the pediatric population appears to be well tolerated with few complications.     

羟基磷灰石义眼台钻孔及栓钉置入术

目的 观察羟基磷灰石义眼台植入后钻孔及栓钉置入术的效果和并发平。方法 ４５例植入羟基磷灰石义眼台的患者,于术后０．５ａ左右行义眼台钻孔及栓钉置入。正确定位后用电钻或手工钻孔,拧入 孔螺钉,将平头钉插入螺钉孔内,结膜水肿消退后换圆头钉,配装活动性义眼。平均随访１３．６ｍｏ。结果 一次手术成功率为８２．２％。并发症有钻孔偏位、偏斜、孔浅钻孔处慢性肉芽肿、感染等,发生率为２２．２％。经治疗后不影响活动性义眼片安装。结论 羟基磷灰石义眼台钻孔及栓钉置入术改善义眼外观。钻孔及栓钉置入术的时机定位和钻孔准确是手术成功的关键。     

Behavior of various orbital implants under axial compression

PURPOSE: To determine and compare the amount of force required to disrupt the integrity of various orbital implants. METHODS: Compression tests were carried out by using a servo-electrical universal testing system on orbital implants including aluminum oxide (Bioceramic implant, FCI, Issy-Les-Moulineaux, France), coralline hydroxyapatite (HA) (Bio-Eye, Integrated Orbital Implants, Inc., San Diego, CA, U.S.A.), bovine HA (Molteno M-Sphere, IOP Inc., Costa Mesa, CA, U.S.A.), synthetic HA (FCI3, FCI, Issy-Les-Moulineaux, France), Chinese HA (H + Y Comprehensive technologies, Philadelphia, PA, U.S.A.), polylactic acid (Kinsey Nash Corporation, Duluth, MN, U.S.A.), porous polyethylene (Medpor, Porex Surgical Inc., College Park, GA, U.S.A.), and polymethylmethacrylate. RESULTS: Two basic groups of implants were identified: those that eventually reach a critical compression point and collapse (coralline HA, aluminum oxide, synthetic FCI3 HA, bovine HA, Chinese HA, and polymethylmethacrylate), and those that do not collapse but gradually compress with increasing load (porous polyethylene, polylactic acid). For similar-sized implants, the critical collapse point was earliest for the FCI3 HA implant, followed by the coralline HA, aluminum oxide, and polymethylmethacrylate implants. Smaller-sized collapsible implants showed earlier critical collapse points than larger-sized implants of similar material. CONCLUSIONS: A technique was established to assess the force required to disrupt the integrity of various orbital implants that is reliable, unbiased, and repeatable with any orbital implant. Orbital implants of different materials and sizes demonstrate different degrees of integrity. It is important to use similar-sized implants when comparing the integrity of different implant materials because size influences the force required to overcome the structural integrity of the implant.     

Proliferation of human fibroblasts in vitro after exposure to orbital implants

BACKGROUND: Porous orbital implants allow fibrovascular ingrowth and integration with the extraocular muscles. The available implants have different structural characteristics, which may influence orbital response. We studied the proliferation of orbital fibroblasts in vitro after exposure to four different orbital implants. METHODS: Four orbital implant biomaterials were studied: hydroxyapatite (Bio-Eye), synthetic hydroxyapatite, porous polyethylene (Medpor) (pore sizes 150 microm and 400 microm) and aluminium oxide (Bioceramic implant). Human fibroblasts obtained from orbital fat at the time of elective blepharoplasty were cultured and then exposed to the individual implants. Cell growth was assessed with immunocytochemical analysis using bromodeoxyuridine, a thymidine analogue. After DNA denaturation, the cells were washed, incubated with secondary antibody and visualized. RESULTS: The fibroblasts growing on the Bio-Eye, synthetic hydroxyapatite, and 150-microm and 400-microm Medpor implants all had debris associated with them. The Bioceramic implant was free of this debris. The Bioceramic implant and the 150-microm Medpor implant had the greatest number of fibroblasts on the coverslips. INTERPRETATION: The proliferation of fibroblasts, as determined by visualization of actively dividing cells with bromodeoxyuridine, differed on the various implants studied. The lack of debris associated with the Bioceramic implant may be related to the crystalline structure of the implant.