Hydroxyapatite Orbital Implants Research Articles

Longitudinal Comparison of Orbital Volumes from Enucleated Eyes with Hydroxyapatite Orbital Implant in Unilateral Retinoblastoma Patients.

To compare the orbital volume between enucleated and contralateral, uninvolved orbits over a 5-year period in patients with unilateral retinoblastoma who underwent enucleation with hydroxyapatite (HA) implant placement by a single surgeon. A retrospective review was performed on the clinical records and radiographic images of unilateral retinoblastoma patients who underwent enucleation with primary HA implantation from 2003 to 2020 at a single institution. Bilateral orbital volume measurements were taken from the initial postoperative MRI scan and again at 1- and 5-years postenucleation. The main outcome measure was the longitudinal change in volume difference (∆𝑉). The implant size, age at enucleation, and sex were also evaluated. A linear mixed-effect model was used for analysis. A total of 124 patients (73 males) with HA implants following enucleation were included. Overall, the unaffected orbit trended toward having a greater volume compared with the enucleated orbit, but this was not statistically significant (β = 0.003; p = 0.122). The mean age at enucleation was 2.4 years. The median time between enucleation and the initial, 1-year, and 5-year postoperative MRIs was 6 months, 17 months, and 55 months, respectively. There was no statistical correlation between age at enucleation, gender, implant size, or orbital volume at any time points ( p > 0.05). Patients treated with enucleation and primary HA implant placement for unilateral retinoblastoma did not display significant asymmetry in orbital volume on 5-year postenucleation MRIs, suggesting that HA implants promote orbital growth comparable to a nonenucleated orbit in the pediatric population.

Case series of shrinking hydroxyapatite orbital implants

BackgroundAn orbital implant is used after enucleation or evisceration surgery to replace the volume lost and to aid in prosthesis fitting and movement. Different materials have been used through the...

Auricular cartilage versus donor sclera as a wrapping of hydroxyapatite orbital implants.

To retrospectively compare postoperative outcomes after primary enucleation and placement of a hydroxyapatite (HA) implant without wrapping, wrapped with auricular cartilage or donor sclera. Medical records of patients presented as intraocular tumor or severe ocular injury were identified from the electronic medical record system. Cases underwent enucleation and HA orbital implantation were enrolled in this study and were divided into 3 groups according to the wrapping material of HA implant. Cases with autogenous cartilage caps were enrolled in group A (n=11), with donor sclera caps in group B (n=12), and without any wrapping material in group C (n=9). Follow-ups were set at 1, 2wk, 1, 3, 6, and 12mo after surgery. Altogether 32 cases finished the follow-up and were enrolled in this study. Three cases (27.27%) in group A, 4 cases (33.33%) in group B, and 4 cases (44.44%) in group C developed one complication each after surgery. In group A, no HA exposure occurred, but conjunctival inclusion cyst occurred in one and severe conjunctive chemosis in two cases. In group B, one HA exposure occurred, conjunctive inclusion cysts occurred in one, severe conjunctive chemosis occurred in one, and conjunctival granuloma occurred in one case. In group C, one HA exposure occurred, severe conjunctive chemosis occurred in two cases, and conjunctival granuloma occurred in one case. The case of exposure of none-wrapped implant was noted in the first 6mo after placement of the orbital implant. The case of exposure of donor sclera-wrapped implant was noted at the 12mo after placement of the orbital implant. Both exposure cases were treated successfully with conservative treatment. With low incidence of implant exposure and mild complications, auricular cartilage can be a good choice of alternative wrapping material of orbit implant with satisfied outcome.

Biological role of postoperative low level laser therapy in preventing hydroxyapatite orbital implantation exposure: A case report.

Conjunctival sac stenosis is the contraction of the conjunctival sac as a result of trauma or disease. The aim of the present study was to observe the clinical effects of low-level laser therapy (LLLT) combined with hydroxyapatite (HA) orbital implantation as a treatment strategy for conjunctival sac stenosis. A total of 10 patients with conjunctival sac stenosis were treated with scleral graft transplantation in conjunction with HA implantation and postoperative LLLT. In addition, a rabbit model was used to investigate the biological mechanism underlying the effects of LLLT with the aim of preventing and treating orbital implantation exposure. The right eyeball was removed, orbital implantation performed and LLLT applied to experimental groups. 99mTc-Methyl diphosphonate scanning methods were performed at different timepoints to compare the average radioactivity count of the region of interest between surgical (right) and control (left) eyes (R/L). Histopathological examination was performed 8 weeks post-surgery, followed by analysis of fiber vascularization. Following LLLT, moderate conjunctival wounds were completely healed within 2 weeks and severe stenosis wounds healed within 3 weeks. Following prosthesis implantation in the rabbit model, a significantly elevated R/L ratio was observed after 4 weeks, whereas no significant difference was observed compared with the control group at 6 and 8 weeks postoperatively. Histopathological examination revealed that all implants were fibrotic. Overall, the present study demonstrated that LLLT promoted the survival of conjunctival grafts, stimulated conjunctival incision healing and promoted early vascularization of HA implants. Clinical trial registration no: ChiCTR-DDT-12002660 (www.chictr.org/cn/).

Unwrapped hydroxyapatite orbital implants: our experience in 347 cases.

To report the results of a large case series of enucleations with primary insertion of an unwrapped hydroxyapatite (HA) orbital implant. We retrospectively reviewed consecutive enucleations with primary orbital (HA) implant insertion performed at the Scottish Ocular Oncology Service, Glasgow between 1990 and 2014. The unwrapped hydroxyapatite orbital implant was placed in the posterior portion of the socket and recti muscles sutured end-to-end over the implant. Out of 347 consecutive enucleations, the indication for enucleation was tumour-related pathology in 59.7% and painful blind eye in 40.3%. Majority (70%) received an implant of 22-mm diameter. At an average follow-up of 3.5 years, complications included post-enucleation socket syndrome (11.5%), chronic discharge (9.2%), chronic pain (4.3%), recurrent conjunctival infection (2.3%),conjunctival cysts (2%), contracted socket (1.4%), implant exposure (1.2%), haematoma (0.6%) and ill-fitting prosthesis (0.6%). Implant exposure (1.2%, n = 4) occurred at a mean of 4.5 months post surgery and was managed by temporalis fascia graft (n = 1), tarsoconjunctival flap (n = 1), implant removal (n = 1) and observation (n = 1). Overall, 9.8% of patients needed further surgery including lower lid tightening (4.3%), ptosis repair (2.3%), conjunctival cyst excision (1.2%), fornix reconstruction (1.2%), graft/flap for exposure (0.6%) and implant removal (0.3%). A low rate of implant exposure indicates that absence of wrapping material around hydroxyapatite orbital implants does not compromise surgical outcomes and has the added benefit of reduced surgical time and avoidance of complications from wrapping materials. Posterior implant placement and end-to-end recti suturing contribute to the success of the procedure.

Clinical observation on hydroxyapatite orbital implantation in muscle cone behind autologous sclera

Objective To observe the clinical efficacy of hydroxyapatite orbital implantation in muscle cone behind autologous sclera. Methods The data of 28 cases who after ocular enucleation received implantation of hydroxyapatite orbital in muscle cone behind autologous sclera at first-stage from Feb.2012 to Mar.2018 was analyzed retrospectively.The followed up time was 2-24 months. The postoperative efficacy were observed. Results The wounds healed well in 28 cases.The conjunctiva did not split, the hydroxyapatite orbital was not exposed and displaced. The orbit were full, the appearance in all cases as symmetrical, and the patients were satisfied. Conclusion The hydroxyapatite orbital implantation in muscle cone behind autologous sclera is simple, and the postoperative prosthetic eye is not easy to be exposed. Key words: Sclera, autologous; Implantation, hydroxyapatite orbital, muscle cone

四片三角形筋膜瓣在羟基磷灰石义眼台植入术中的应用

四片三角形筋膜瓣在羟基磷灰石义眼台植入术中的应用

Treatment of Exposed Hydroxyapatite Orbital Implants Wrapped with a Synthetic Dura Substitute.

PurposeTo describe cases of exposed hydroxyapatite (HA) implants wrapped with the synthetic dura substitute Neuro-Patch treated via simple Neuro-Patch removal.MethodsThe medical records of seven patients who experienced exposure of their HA implant were reviewed. All patients had been enucleated and implanted with HA wrapped with Neuro-Patch. For treatment, Neuro-Patch was removed to the greatest extent possible. After applying local anesthesia with lidocaine, blunt dissection was performed to separate the conjunctiva and Neuro-Patch via the site of exposure. Pressure was applied to the remaining Neuro-Patch with forceps and removed with scissors.ResultsNeuro-Patch was visible at the area of exposure in all patients. No surgery beyond initial Neuro-Patch removal was necessary in six of the seven patients. In five cases, the exposed area began to heal rapidly after Neuro-patch removal without primary closure of the defect. In one case, the Neuro-Patch material and all necrotic tissue was removed aggressively due to inflammation around the orbital implant. Lastly, an infection was noted in one case, prompting complete removal of the Neuro-Patch–wrapped HA implant.ConclusionsWrapping material may hinder implant vascularization. Exposure of HA in wrapped implants can be successfully treated by a simple removal procedure if detected and managed early.

Synergistic Effect of Copper-Containing Mesoporous Bioactive Glass Coating on Stimulating Vascularization of Porous Hydroxyapatite Orbital Implants in Rabbits

Rapid and complete vascularization of the porous orbital implants after enucleation is vital for reducing postoperative complications, such as exposure and infection. In this study, the porous hydroxyapatite (pHA) scaffolds modified with the mesoporous bioactive glass with and without adding copper (MBG, Cu-MBG) were prepared by sol-gel technique and followed by evaporation induced self-assembly (EISA) process. The macro-/microstructure analysis of the modified scaffolds (i.e., MBG/pHA, Cu-MBG/pHA) showed highly interconnected macropores, and unique mesoporous structures in the pore wall with higher surface area. A primary angiogenic test in a panniculus carnosus muscle model in rabbit indicated that the Cu-MBG coating was significantly beneficial for the vascularization in the porous architecture of the scaffolds in the early stage. These results suggest that the Cu-MBG modification provides a simple and effective strategy to endow favorable biological performances with pHA implants and greater potential for future application in orbit reconstruction.

The effect of orbital implantation on peripheral blood melatonin and sex hormone levels in child patients with congenital eyeball dysplasia.

The aim of the study was to examine the effect of orbital implantation on peripheral blood melatonin and sex hormone levels in pediatric patients with congenital eyeball dysplasia. A total of 28 cases of pediatric patients with congenital eyeball dysplasia diagnosed in the Second Affiliated Hospital of Xi'an Jiaotong University from June 2014 to December 2014 were selected for the study. The patients included those that received orbital implantation, and the melatonin levels in the peripheral blood in patients before and after operation was observed. In addition, the sex hormone levels and T lymphocytes, plasma reactive oxygen species (ROS) and VEGF levels, urine 8-OHdG and 8-isoPGF2α levels in patients before and after treatment were detected, followed by statistical analysis. As a result, after 3 months of orbital implantation, the sex hormone levels in peripheral blood in child patients fluctuated significantly, and differences were not statistically significant (P>0.05). The peripheral blood T lymphocytes and ROS levels were significantly lower than those before treatment, and the differences were statistically significant (P<0.05). The correlation analysis revealed that the peripheral blood melatonin levels were negatively related to ROS levels; the correlation coefficient was rs = −0.481 and P<0.05. In conclusion, orbital implantation does not have significant impact on sex hormone levels in child patients with congenital eyeball dysplasia. The hydroxyapatite orbital implantation can achieve more satisfactory curative effects, and there are fewer postoperative complications. It does not affect the appearance of the eye, and therefore, it is suitable for patients with congenital eyeball dysplasia.

Clinical observation on exposure of orbital implant repaired by heart dacron graft

Objective To observe the clinical efficacy and safety of moderate to severe exposure of orbital implant repaired by heart dacron graft. Methods Thirty-six cases after surgery hydroxyapatite orbital implantation with moderate to severe exposure of orbital implant were repaired. The surface of the exposed hydroxyapatite implant was smoothed by powered grader and covered with a diameter of 20 mm heart polyester patch, to repair the defect of fascia and conjunctiva. The follow-up time was 6-24 months. Results In 36 cases, 34 cases were primary healing except 2 cases of poor conjunctival healing. After 1 month conservative treatment, the conjunctiva healed.No orbital implant exposure recurrented.The artificial eyes moved well. Conclusion Application of heart dacron graft is an effective method for repairing of orbital implant exposure. Key words: Orbital implant, hydroxyapatite; Exposure; Repair; Heart dacron graft

Exposure rate of unwrapped hydroxyapatite orbital implants in enucleation surgery

ObjectiveTo document the long-term exposure rate of unwrapped coralline hydroxyapatite (HA) orbital implants and explore possible risk factors.DesignThis retrospective case series (May 2008–April 2013) reviewed the 234 patients with anophthalmia...

A biomimetic collagen/heparin multi-layered porous hydroxyapatite orbital implant for in vivo vascularization studies on the chicken chorioallantoic membrane.

The vascularization of an orbital implant is a key issue for reducing complications, such as exposure and infection. Here, we developed a facile layer-by-layer assembly approach to modify porous hydroxyapatite (pHA) orbital implants with five collagen (COL)/heparin (HEP) multilayers. SEM characterization showed that the average pore size of the pHA/(COL/HEP)5 scaffold was 316.8 ± 77.1 μm. After being coated with five COL/HEP multilayers, the mechanical strength was improved compared with that of the pHA scaffolds. The in vitro assay displayed that the pHA scaffolds covered with COL/HEP multilayers resulted in a larger number of human umbilical vein endothelial cells after being cultured for 14 days. The macroscopic evaluation and semi-quantitative vascular density analysis of the chicken chorioallantoic membrane assay showed that the pHA/(COL/HEP)5 scaffolds resulted in more intense angiogenesis than the pHA scaffolds. These studies demonstrate that the biomembrane-mimicking coating of COL/HEP multilayers is a simple and effective strategy to endow combined biological performances of pHA orbital implants and to potentially reduce implant-related complications.

The clinical application of conjunctival fornix decompression incision in hydroxyapatite orbital implantion surgery

Objective To evaluate the effect of the conjunctival fornix decompressive incison and hydroxyapatite(HA) orbital implantation for narrow conjunctival sac. Methods Primary preoperative and intraoperative observation were performed in 16 patients who underwent the conjunctival fornix decompression incision to treat the narrow conjunctival sac. Results The postoperative observation time was 6 months to 3 years after the surgery. 13 patients were able to wear an normal size ocular prosthesis comfortably. Other 3 patients were able to wear an custom made ocular prosthesis. Conclusion Conjunctival fornix decompression incision hydroxyapatite(HA) implantation is easy and effective for the narrow conjunctival sac. Key words: Decompression incision, fornix; Conjunctival sac, narrow; Hydroxyapatite(HA)

The efficacy of petal shape sclera forming hydroxyapatite(HA) orbital implantation

Objective To investigate the efficacy of petal shape sclera forming hydroxyapatite (HA) orbital implantation. Methods Twenty-eight eyes of 28 patients received petal shape sclera forming HA orbital implantation. The follow-up time was 6 to 24 months.The operative effects were observed. Results Thin bulbar conjunctiva occurred in 1 case of 28 cases and the scleral suture exposed. The fascia and conjunctiva were sutured again 1 month later. Conjunctival sac was narrow slightly in one case. No orbital implant exposure, extrusion, infection or other complication was found. Conclusion The petal shape sclera forming HA orbital implantation has good effects and less complication. Key words: Implantat, orbital; Hydroxyapatite; Implantation

Original hydroxyapatite orbital implant covered with small autoscleral flap with extraocular rectus muscles orbital implantation

Objective To observe the clinical efficacy of orbital implantation with original hydroxyapatite (HA) orbital implant covered with small autoscleral flap at extraocular rectus muscles insertions area which was designed by the author. Methods Thirty-two cases were randomly selected from a total of 296 patients who were treated with the original hydroxyapatite implantation method. Serial precontrast and postcontrast T1-weighted magnetic resonance imaging (MRI) were obtained at 1 week, 1, 2, 3, 4, 5, 6 and 18 months after implantation to assess the fibrovascularization of HA orbital implants. Results Patients were followed up for 1to18 months. In all cases HAs were fixed to orbit and moved well. There was no complication of prostheses exposure. Contrast-enhanced MRI showed the HA spheres had achieved complete vascularization 1 month after implantation. The vascularization density increased with time. Conclusion The author's original hydroxyapatite orbital implantation covered with small autoscleral flap with extraocular rectus muscles method completely solves the problem of prostheses exposure complication and its advantage of promoting the fibrovascularization is obvious. The application prospect is good. Key words: Implant, orbital, hydroxyapatite; Autoscleral flap, small

Hydroxyapatite versus polyethylene orbital implants for patients undergoing enucleation for uveal melanoma

ObjectiveClinical outcomes for enucleation vary widely, depending on surgical technique, implant choice, and indications for enucleation. The goal of this study was to compare complications of enucleation using hydroxyapatite versus polyethylene orbital implants for 1 indication: uveal melanoma in adults. DesignRetrospective chart review ParticipantsConsecutive case series of patients who were enucleated for uveal melanoma by a single surgeon (J.W.H.) from 1999-2009. MethodsA retrospective chart review was performed to record clinical and histopathologic features, surgical technique, orbital implant characteristics, and outcomes in a consecutive series of patients with uveal melanoma who were treated by enucleation by a single surgeon (J.W.H.) between 1999 and 2009. ResultsThis study included 139 patients; 64 received hydroxyapatite implants, and 75 received polyethylene implants wrapped in donor sclera. Complications included blepharoptosis in 4 (2.9%), conjunctival cyst in 2 (1.4%), volume deficit in 2 (1.4%), implant exposure in 1 (0.7%), and conjunctival erosion in 1 (0.7%) patient. There were no significant differences in the clinicopathologic features or complications between the 2 groups. ConclusionsFew complications were encountered using this enucleation technique, and there was no difference in complication rates between patients receiving hydroxyapatite and polyethylene implants.

Hydroxyapatite orbital implant in children following enucleation: analysis of 531 sockets.

To evaluate the features and long-term outcomes of hydroxyapatite (HA) orbital implant following enucleation in pediatric patients. A retrospective review was performed on clinical records of patients ≤18 years of age , managed with enucleation and HA implant placement. Recorded outcomes included implant-related complications, implant and prosthesis motility, and patient cosmetic satisfaction. There were 525 children (531 sockets) with HA implant following enucleation. The mean age at HA implant placement was 3 years (median, 2 years; range, 4 days to 17 years). Indications for enucleation included retinoblastoma (n = 457, 86%), uveal melanoma (n = 17, 3%), medulloepithelioma (n = 8, 2%), and others (n = 49, 9%). The HA implant was uncoated (n = 370, 70%) or polymer coated (n = 161, 30%). For the 370 uncoated implants, wrapping was provided with scleral (n = 346, 94%) or bovine pericardium (n = 1, <1%), and 23 patients (6%) had no wrapping. The extraocular muscles were attached to the implant/polymer coat/wrap (n = 531, 100%), by suturing 4 rectus muscles (n = 349, 66%) or all 6 muscles (n = 182, 34%). Over mean follow up of 60 months, in 477 orbital implants, complications included conjunctival thinning (n = 10, 2%), implant infection (n = 6, 1%), implant exposure (n = 13, 3%), and implant migration/extrusion (n = 0, 0%). Motility for implant was judged as excellent (n = 245, 78%) and small-angle prosthesis motility was excellent (n = 196, 59%). Patient/family satisfaction with cosmetic outcome was rated as excellent in 471 implants (99%). Following enucleation in children, long-term outcomes of the HA orbital implant are excellent with favorable patient cosmetic satisfaction and rare complication.

Amniotic membrane transplantation in the treatment of conjunctival rupture, dehiscence and socket contracture after hydroxyapatite orbital implantation

Amniotic membrane transplantation in the treatment of conjunctival rupture, dehiscence and socket contracture after hydroxyapatite orbital implantation

Vascularization of Coralline versus Synthetic Hydroxyapatite Orbital Implants Assessed by Gadolinium Enhanced Magnetic Resonance Imaging

Purpose: To evaluate the fibrovascular in-growth of coralline and synthetic hydroxyapatite orbital implants by reporting the enhancement patterns on Gadolinium-Dietilen triamin penta acetic acid (Gad-DTPA) enhanced magnetic resonance imaging (MRI).Methods: The medical records of 26 patients who had undergone primary or secondary orbital implantation between April 2008 and February 2011 were reviewed. T1 weighted Gad-DTPA MRI was performed between 5 and 12 months (mean 9.2 ± 5.9 months) after implantation and graded as follows to evaluate the fibrovascular in-growth of the implants; grade 1 (rim enhancement), grade 2 (peripheral foci of enhancement, not including the center), grade 3 (central, non-homogenous enhancement), grade 4 (central, homogenous enhancement) and grade 5 (central, intense enhancement).Results were analysed according to vascularization patterns on Gad-DTPA MRI.Results: Central vascularization patterns (grade 3, 4 or 5) were seen 62.5% of coralline orbital implants and 46.1% of synthetic orbital implants. Central fibrovascular in-growth of the coralline implants were found significantly more than synthetic implants (p < 0.05). Central vascularization of coralline implants with primary implantation was 75% and with secondary implantation was 50%. Synthetic orbital implantation with primary surgery demonstrated 66.6% and synthetic orbital implantation with secondary surgery demonstrated 26.6% central vascularization pattern. In both natural coralline and synthetic implants, primary orbital implantation was demonstrated significantly better fibrovascular in-growth than secondary implantation (p < 0.05). Two patients with synthetic orbital implants had dehiscence that was repaired by using autogenous fascia lata.Conclusions: In both coralline and synthetic orbital implants, central vascular in-growth was observed much more with primary orbital implantation. This study indicates that coralline HA orbital implants significantly supply more rapid and homogenous vascularization than synthetic implants.