Hydroxyapatite orbital implant exposure in children

Correction of orbital implant exposure using a supra-brow island flap pedicled with orbicularis oculi muscle

PURPOSE

To describe our experience of the supra-brow island flap pedicled with orbicularis oculi muscle technique for correcting orbit implant exposure.

MATERIALS AND METHODS

This retrospective study reviewed 32 patients that underwent orbit implant exposure surgery using a supra-brow island flap pedicled with orbicularis oculi muscle. All data were reviewed from patients in Eye & ENT Hospital of Fudan University, Shanghai during January 2018 to July 2020. The patient demographics, the original etiology, surgical procedures, implant types, and follow-up interval were recorded. The primary outcome was the long-term coverage of the supra-brow island flap pedicled with orbicularis oculi muscle, and the post-surgical complications and management were secondary outcomes.

RESULTS

28 eyes of 28 patients had functional results and satisfactory cosmetic outcomes at final follow up(range, 9-29 months). Among the other 4 patients, the recurrence of exposure was recorded during the follow-up, two of these patients successfully underwent dermis fat grafts(DFGs), one recovered after conservative treatment, and one refused treatment.

CONCLUSIONS

The supra-brow island flap pedicled with orbicularis oculi muscle is a technique available to manage orbital implant exposure when other simpler and more direct techniques have been tried and failed.

PRECIS

A new flap for orbital implant exposure.

Risk Factors for Trauma-Related Eviscerations: Analysis of 821 Cases

Evisceration is the end therapeutic approach for the treatment of severe ocular trauma cases, and it is a tremendous loss for patients. In this study, we explored the changing trends in the number of surgeries performed, demographic data and ocular features, and risks for early evisceration, aiming to provide more data for the additional prevention and management strategies for this catastrophic problem. This was a retrospective study that included patients who underwent ocular evisceration at the Zhongshan Ophthalmic Center between January 2013 and December 2017. A total of 1229 evisceration cases were reviewed, and only trauma-related eviscerations were analyzed. Etiology, demographic data, ocular features, and hospitalization time were evaluated. The total number of trauma-related eviscerations recorded in the past five years was 821 cases. The number of surgeries performed was almost constant each year (164 ± 17 cases); 35% of the patients were less than ten years old at the time of the original ocular injury and 69% of them were male. Endophthalmitis led to significantly early evisceration compared with cases without endophthalmitis (P < 0.05). The group with a history of silicone oil tamponade showed a significantly longer surgical interval between trauma and evisceration than did the nonsilicone oil tamponade group (P < 0.05). Day-case hospitalization for evisceration increased from 0% to 32% over the past five years. The results of the present study show that the number of ocular trauma-related eviscerations performed in the past five years was almost unchanged and boys under ten are highly susceptible. This study also demonstrates that endophthalmitis leads to significantly early evisceration, and silicone oil tamponade may postpone ocular atrophy. Based on the study data, day-case surgery is safe for evisceration management.

Orbital implant exposure following enucleation or evisceration

PURPOSE

To study the exposure rate of orbital implant postenucleation or evisceration procedures in two tertiary hospitals in Oman.

DESIGN

A retrospective, descriptive, cross-section study.

MATERIALS AND METHODS

Patients' records were reviewed for patients' demographics, surgical indications, implant types, follow-up and any reported complications after surgeries. Patients with a minimum of 1 year follow-up period were selected. All patients who underwent enucleation or evisceration with primary orbital implant were included in the study. Patients who underwent secondary orbital implant were excluded from the study.

RESULTS

A total of 37 patients (age between 4 and 88-year-old, median age is 54-year-old) underwent enucleation or evisceration during 2008-2014. The most common indications for the surgical intervention were painful blind eye (35%), followed by trauma (16%), and perforated corneal ulcer (16%). Out of 37 patients, hydroxyapatite implant was implanted in 17 patients (46%), a glass or acrylic implant was implanted in 17 patients (46%), bioceramic implant was implanted in two patients (5%), and Molteno prosthesis was implanted in one patient (3%). There was no case of orbital implant exposure in any patients in this study.

CONCLUSIONS

No orbital implant exposure was recorded in this study. The surgical technique, end to end rectus muscles suturing, used for enucleation/evisceration was the main reason for reduced implant exposure. In addition, the preexisting ocular pathology did not affect the outcome of the study.

Dermis-Fat Graft in Children as Primary and Secondary Orbital Implant

PURPOSE

To report the experience with the use of dermis-fat graft in the pediatric population and to evaluate the outcome of this procedure as a primary or secondary orbital implant.

METHODS

Case series. Analysis of the clinical charts of 22 patients. Age at the time of surgery ranged from 2.1 to 13 years. Three patients affected were submitted to evisceration with primary dermis-fat graft. Six patients had explantation of exposed implants and a replacement with a dermis-fat graft. Three patients had a dermis-fat graft to repair contracted sockets. Ten patients were affected by congenital anophthalmia: 4 patients had a primary dermis-fat graft, 6 patients had a removal of a socket expander, or an orbital spherical expander, or pellet expanders and a replacement with a dermis-fat graft. This study adheres to the principles outlined in the Declaration of Helsinki.

RESULTS

The patients' follow up ranged between 2.5 and 8 years. Only 1 child who had a primary dermis-fat graft experienced excessive growth of the implant, managed by surgical debulking. In the end, all the patients showed satisfactory orbital volume along with adequate fornices.

CONCLUSIONS

The dermis-fat graft as a primary implant may be useful in children with severe scleromalacia or following ocular trauma. It is a suitable option in children affected by congenital anophthalmia as it helps continued socket expansion. It can also be considered in the pediatric population to address the volume deficit following explantation of exposed implants and in contracted sockets.

Complications of orbital endoimplantation in the Eye Clinic of the Lithuanian University of Health Sciences

The aim of the study was to analyse the rate of complications of orbital endoimplantation in patients operated from 2002 to 2014 at the Eye Clinic of the Lithuanian University of Health Sciences and to compare it with the results in the literature. Enucleation must be performed very carefully in order to prevent any additional trauma, infection, deformation, and to create an optimal conjunctival socket. However, complications occur despite efforts and qualified surgeons. The most common complications described in the literature are thinning and cysts of the conjunctiva, a foreign body reaction, secretion, symblepharons, fornix deficiency, ptosis, permanent pain, dislocation, migration and protrusion of the implant, a primary or secondary infection, and implant extrusion. From 2002 to 2014, 128 patients underwent orbital endoimplantation surgery at the Eye Clinic. The most common complications were conjunctival erosion (five patients, or 2.9%), cysts (nine patients, or 7%), and implant extrusion (five patients, or 2.9%). The type and rate of complications were very similar to the data in the literature.

Orbital implants in retinoblastoma patients: 23 years of experience and a review of the literature

PURPOSE

To evaluate complications of different types of orbital implants following enucleation for retinoblastoma.

METHODS

We performed a retrospective chart study of all patients that underwent enucleation as treatment of retinoblastoma between April 1991 and June 2013. Events of implant exposure, extrusion (defined as a complete loss of the implant, or a major exposure that could not be closed) and socket abnormalities were analysed for association with implant type and influence of additional external beam radiation therapy (EBRT) and/or chemotherapy.

RESULTS

A total of 224 enucleations in 216 patients (eight bilateral) were identified. Mean age at surgery was 1.9 (median 1.5) years. Of the 219 included enucleated eyes, 20 were not replaced by a primary implant and 18 were replaced by an Allen implant. Scleral wrapped hydroxyapatite (HA) and acrylic implants (polymethylmethacrylate) were inserted in, respectively, 79 and 102 cases. In the total population, 29 treatment or implant-specific events (13.2%) were registered. Main complications were implant exposure n = 10 (4.6%) and extrusion n = 6 (2.7%). The acrylic/sclera group had less exposures or extrusions (5 of 102, 4.9%) compared to the HA/sclera group (10 of 79, 12.7%), although this difference did not quite reach statistical significance (p = 0.06). Additional treatment (chemotherapy and/or EBRT for the fellow eye) was administered in 78 cases (35.8%). The overall complication rate in the entire study population was significantly higher (16.7% versus 5.7%) in the group exposed to additional therapy (OR 3.3; 95% CI 1.30-8.36 p = 0.008). This negative effect of additional therapy was also significant in the combined acrylic/HA group (OR 2.9; 95% CI 0.97-8.46 p = 0.048).

CONCLUSION

Our results suggest a favourable outcome for acrylic implants compared to the HA implant. Additional treatment with chemotherapy and/or EBRT is associated with an increased risk of complications.

Bioceramics in ophthalmology

The benefits of ceramics in biomedical applications have been universally appreciated as they exhibit an extraordinarily broad set of physico-chemical, mechanical and biological properties which can be properly tailored by acting on their composition, porosity and surface texture to increase their versatility and suitability for targeted healthcare applications. Bioceramics have traditionally been used for the repair of hard tissues, such as bone and teeth, mainly due to their suitable strength for load-bearing applications, wear resistance (especially alumina, zirconia and composites thereof) and, in some cases, bone-bonding ability (calcium orthophosphates and bioactive glasses). Bioceramics have been also applied in other medical areas, like ophthalmic surgery; although their use in such a context has been scientifically documented since the late 1700s, the potential and importance of ceramic ocular implants still seem to be underestimated and an exhaustive, critical assessment is currently lacking in the relevant literature. The present review aims to fill this gap by giving a comprehensive picture of the ceramic-based materials and implants that are currently used in ophthalmology and pointing out the strengths and weaknesses of the existing devices. A prospect for future research is also provided, highlighting the potential of new, smart bioceramics able to carry specific added values which could have a significant impact on the treatment of ocular diseases.

The versatility of the temporoparietal fascial graft (TPFG) in orbital implant exposure

BACKGROUND

The use of TPFGs for hydroxyapatite, porous polyethylene and silicone implant exposure has been described previously. To the authors' knowledge, this is the first description of this technique for acrylic implant exposure and paediatric patients.

PURPOSE

To demonstrate the versatility of the TPFG in orbital implant exposures of varying duration, implant types and patient age as well as for recurrent exposure.

METHODS

Retrospective, interventional, non-comparative case series.

RESULTS

Twelve patients (13 grafts) are presented with a mean follow-up of 9.5 months. The duration of exposure prior to grafting ranged from 1-11 months occurring in bioceramic, hydroxyapatite, porous polyethylene and acrylic implant types. There were 2 graft failures (success rate 84.6%), one of which was treated with a 2nd TPFG. Two of the cases were from the paediatric age group.

CONCLUSION

This study provides further supporting evidence for the safety and efficacy of the TPFG and demonstrates the use of this graft in a variety of different clinical situations.

Biomaterials for orbital implants and ocular prostheses: overview and future prospects

The removal of an eye is one of the most difficult and dramatic decisions that a surgeon must consider in case of severe trauma or life-threatening diseases to the patient. The philosophy behind the design of orbital implants has evolved significantly over the last 60 years, and the use of ever more appropriate biomaterials has successfully reduced the complication rate and improved the patient's clinical outcomes and satisfaction. This review provides a comprehensive picture of the main advances that have been made in the development of innovative biomaterials for orbital implants and ocular prostheses. Specifically, the advantages, limitations and performance of the existing devices are examined and critically compared, and the potential of new, smart and suitable biomaterials are described and discussed in detail to outline a forecast for future research directions.

The effect of cancer therapies on pediatric anophthalmic sockets

PURPOSE

To determine the impact of chemotherapy or external beam radiotherapy (EBRT) on pediatric anophthalmic sockets.

DESIGN

A retrospective, nonrandomized, interventional cohort study.

PARTICIPANTS

A total of 135 sockets of 133 children undergoing enucleation from late 1999 to early 2009 at the St. Jude Children's Research Hospital were included.

METHODS

A retrospective chart review of outcomes after enucleation in patients treated with systemic chemotherapy or orbital EBRT either before or after removal of the eye compared with patients who received no other treatment.

MAIN OUTCOME MEASURES

Incidence of implant exposure, migration, extrusion, socket contracture, and pyogenic granuloma formation.

RESULTS

Retinoblastoma was the primary diagnosis in 128 eyes (95%). Median follow-up was 3.6 years (range, 0.1-9.3 years). Event-free course was observed in 94 sockets (69.6%). Complications included implant exposure (n = 28, 20.7%), socket contracture (n = 16, 11.9%), pyogenic granuloma (n = 9, 6.7%), implant extrusion (n = 3, 2.2%), and migration (n = 2, 1.5%). Exposure resolved in 21 sockets (77.8%) and improved in 2 sockets (11.1%); 1 patient with exposure died. Use of prior, adjuvant, or subsequent chemotherapy increased the long-term risk of exposure (odds ratio [OR] = 3.7; 95% confidence interval [CI], 1.4-9.4), and contracture (OR could not be calculated, P<0.0001). External beam radiotherapy greatly increased the risk of contracture (OR 24.0; 95% CI, 6.9-82.8) and exposure (OR 2.89; 95% CI, 1.1-7.9).

CONCLUSIONS

In this unique pediatric population with cancer, chemotherapy and EBRT had an additive effect, significantly increasing the incidence of exposure and socket contracture.

FINANCIAL DISCLOSURE(S)

The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Frequent prosthesis refitting to prevent implant exposure in patients with retinoblastoma

PURPOSE

To examine the effects of prosthesis refitting on porous orbital implant exposure in 100 patients who underwent enucleation for retinoblastoma.

METHODS

Parameters analyzed included patient's age at enucleation, gender, implant type, frequency of prosthesis adjustment, and use of chemotherapy or radiation. The main outcome measures consisted of the condition of the fornices, condition of the implant (including conjunctival thinning), and condition and functioning ability of the prosthesis.

RESULTS

Increased frequency of visits with the ocularist and number of prosthesis adjustments and refits significantly improved the condition of the implant, fornices, and prosthesis. The patient's age at enucleation, gender, and use of chemotherapy or radiation did not have a significant effect on any of the outcome variables. The condition of the implant was significantly better for porous polyethylene than hydroxyapatite implants (P = .024). No implant exposures were observed.

CONCLUSION

Frequent adjustments and refits by the ocularist are significantly associated with a reduced rate of conjunctival thinning and complete avoidance of implant exposure in patients undergoing enucleation for retinoblastoma. These findings are particularly significant for this population, which historically has demonstrated a high rate of implant exposure.

Unusual presentation of a metastatic uveal melanoma in a cat

A 10 year-old, spayed female Domestic Short-Haired (DSH) cat was diagnosed with a large primary uveal melanoma and exenteration was recommended. Thoracic radiographs, abdominal ultrasonography, and complete blood count and serum biochemistry panel did not reveal any abnormality compatible with metastatic disease and surgery was performed. Histopathologic study of the eye confirmed a diffuse iris melanoma. Five months later, the cat presented with a lameness of the right anterior extremity. On physical exam the right elbow was swollen and painful. Radiographs showed a severe osteolysis of the radial head and proximal diaphysis. Fine needle aspiration of the radius head identified a round cell neoplasm with scattered cells containing intracytoplasmatic pigmented granules, compatible with metastatic melanoma. The owners decided not to treat the patient with chemotherapy and declined a biopsy. Two months later, the cat died and necropsy was performed confirming bone metastasis of the uveal melanoma. A diagnosis of generalized metastasis from primary diffuse iris melanoma was made. This report describes, for the first time, long bone metastasis from an uveal melanoma in a cat.

Primary dermis-fat grafting in children

PURPOSE

To report our experience with the use of primary dermis-fat grafts in the pediatric population.

METHODS

The charts of 12 young patients under the age of 16 years who underwent dermis-fat graft implantation from 1992 to 2004 were reviewed and the functional and cosmetic outcome was assessed.

RESULTS

Ten patients had enucleation combined with primary dermis-fat grafting. Age at the time of surgery ranged from 4.7 to 16 years. One patient was lost to follow-up after 1 year; the remaining 9 had follow-up between 3 to 10.2 years. In 8 of them, appropriate orbital soft tissue volume and good orbital symmetry, with a good prosthetic fit and good motility, were observed. In one patient there was hair growth on the graft, managed by laser coagulation. One child developed central graft ulcer that was repaired. Two children experienced abundant growth of their implants, managed by surgical debulking. Two patients had undergone dermis-fat grafting of congenital anophthalmic sockets, age 13.6 years and 10 months, respectively, at time of surgery. The 10-month-old showed adequate orbital soft tissue volume along with deep fornices (follow-up 6.5 years); the second was lost for follow-up.

CONCLUSIONS

Some minor complications with the use of dermis-fat graft in children occur, but they are easily managed. The dermis-fat graft in young children's orbits appears to grow after implantation. Due to its high degree of safety concurrent with excellent functional and cosmetic results, the dermis-fat transplant appears particularly advantageous for young patients.

Porous orbital implants, wraps, and PEG placement in the pediatric population after enucleation

PURPOSE

To investigate complications of various porous orbital implants and wrapping materials in the pediatric population after enucleation.

DESIGN

A retrospective, comparative, nonrandomized study.

METHODS

Between November 1992 and November 2006, patients younger than 15 years old were collected for study participation. They underwent enucleation with porous orbital implants primarily or secondarily at National Taiwan University Hospital. The authors used the hydroxyapatite (HA), Medpor, and Bioceramic orbital implant. The HA implant was wrapped with four different materials: donor sclera, Lyodura, porcine sclera, and Vicryl mesh. A part of HA implants and all bioceramic implants were wrapped with Vicryl mesh, added anteriorly with scleral patch grafts. All Medpor implants were unwrapped.

RESULTS

Forty-seven cases had more than a two-year follow-up. The exposure rates according to implants and wraps were: donor sclera-wrapped HA (two of nine, 22%), porcine sclera-wrapped HA (three of three, 100%), Vicryl mesh-wrapped HA (one of five, 20%), and unwrapped Medpor (one of four, 25%). No exposure was found in four Lyodura-wrapped HA implants, and 22 Vicryl mesh-wrapped HA and Bioceramic implants with anteriorly scleral coating. The exposure rate was lower in cases with implants wrapped by our method and Lyodura than in those with implants wrapped by other materials (P < .001). Of 47 patients, 20 (42.5%) were fitted with peg-coupled prostheses and all had good prosthetic movements subjectively.

CONCLUSIONS

Different types of implants and wraps resulted in various exposure rates in the pediatric population. The modified wrapping technique may prevent porous implants from exposure in children.

Perspective on Orbital Enucleation Implants

The philosophy and design of orbital enucleation implants have evolved significantly over the past 50 years. Animal studies and improved imaging techniques have changed our understanding about the physiology and anatomy of the post-enucleation orbit. Changes in implant design and biomaterials have reduced complication rates. It is our impression that for many ophthalmic professionals in training, the rational behind the current thinking in implant design and biomaterials is unclear. This is in part related to the older literature on orbital enucleation implants, which is scattered and at times contradictory. This review aims to present the historical information in a coherent and concise form; provide evidence based review of changes in the practice patterns of enucleation; identify areas of continuing controversy; and highlight gaps in the scientific literature about orbital implants, in particular, the poor understanding of implant and prosthesis motility.

Porous Implant Exposure: Incidence, Management, and Morbidity

PURPOSE

To identify what factors may predispose patients to exposure of porous anophthalmic implants and to determine the outcome of exposed porous implants.

METHODS

Examination of pooled data obtained through a PubMed literature search of English-language publications from 1989 through 2004 using the key words enucleation, evisceration, and socket reconstruction.

RESULTS

Porous implants were inserted in 80% (3012 of 3777) of the cases identified from 49 publications. The difference in exposure rate between coralline hydroxyapatite (4.9%) and porous polyethylene (8.1%) implants is primarily related to a higher reported complication rate of uncovered porous polyethylene implants, particularly in retinoblastoma patients. Other techniques associated with increased exposures include wrapping implants with bovine pericardium or polyglactin mesh. Evisceration and secondary procedures did not have statistically different complication rates compared with enucleation. There are more late exposures of porous polyethylene than coralline hydroxyapatite implants. Spontaneous healing of exposures occurred in 13% (19 of 145) of cases. Covering exposures with patch grafts underneath vascularized conjunctival flaps was the most successful method of surgical repair. Implant removal was necessary after 29% (42 of 145) of exposures.

CONCLUSIONS

Although the published literature between 1989 and 2004 reports higher complication rates for uncovered porous implants and implants wrapped with bovine pericardium or polyglactin mesh, pooling data from different studies may mask very good or poor results obtained by individual surgeons. Spontaneous healing of exposed porous implants is relatively uncommon. However, many exposed porous implants can be salvaged with secondary repair.

Exposure of Orbital Implants Wrapped With Polyester-Urethane After Enucleation for Advanced Retinoblastoma

PURPOSE

Enucleation is the main form of treatment for advanced retinoblastoma. The major complication of this procedure is orbital implant exposure. Different implants and wrapping materials are currently in use. The aim of the current study was to analyze the complications associated with the use of polyester-urethane, an artificial dura substitute, as a wrapping material for enucleation in advanced retinoblastoma.

METHODS

A retrospective review of 32 cases (28 patients), who were treated with enucleation for advanced retinoblastoma, was performed. The age of the patients ranged between 3 months and 6.7 years (median, 19 months). Additional chemotherapy was administered in 12 cases. The removed eyeball was replaced either with a silicone implant and polyester-urethane wrapping (13 cases) or hydroxyapatite, silicone-hydroxyapatite, or polyethylene implants without additional wrappings (19 cases). The follow-up period ranged from 7 months to 5.9 years (median, 22.4 months). Statistical analysis was performed using the Kaplan-Meier method.

RESULTS

Single or multiple exposures occurred in 22% of cases (7/32). There were 6 exposures (46%, 6/13) in the group with polyester-urethane wrapping compared with only 1 exposure (5%, 1/19) in the implants without wrapping. This difference was statistically significant (p=0.0236). None of the other analyzed factors (additional chemotherapy, surgeon, age of the patient, or size of the implant) demonstrated a significant correlation to implant exposures.

CONCLUSIONS

Wrapping of orbital implants with polyester-urethane resulted in a high rate of implant exposures after enucleation for advanced retinoblastoma. In this series, the best results were achieved with integrated implants without additional wrapping.

Management of the anophthalmic socket in pediatric patients

PURPOSE OF REVIEW

The management of the pediatric anophthalmic socket is distinguished from adult anophthalmia, because normal socket and facial development is dependent on orbital growth. Recent literature on managing anophthalmic sockets is discussed with a focus on the pediatric patient.

RECENT FINDINGS

There are many studies discussing the management of the anophthalmic socket, but few are randomized clinical studies. Although the management of anophthalmia in the child is fraught with challenges and nuances, the principal aim is to encourage socket growth.

SUMMARY

Both congenital and acquired pediatric anophthalmia are discussed. Surgical decisions, choice of orbital implants, various methods of socket expansion, and socket reconstructions are examined.

Fibrovascular ingrowth into hydroxyapatite and porous polyethylene orbital implants wrapped with acellular dermis

PURPOSE

Acellular dermis is a frequently used wrapping material for hydroxyapatite (HA) and porous polyethylene (PP) orbital implants. In an animal model, we determined by histology the extent of fibrovascular ingrowth within orbital implants wrapped in acellular dermis at 6 and 12 weeks after surgery.

METHODS

Four Yucatan minipigs were used for the study. Two minipigs had HA implants and two had PP implants. Implants were harvested at 6 or 12 weeks after surgery and were examined histologically for fibrovascular ingrowth.

RESULTS

There was complete fibrovascularization of HA implants harvested at both 6 and 12 weeks after surgery. The PP implant harvested at 6 weeks had incomplete fibrovascularization, whereas the PP implant harvested at 12 weeks had complete fibrovascular ingrowth. There was no histologic evidence of inflammation seen in any of the orbital implants. On gross and histologic examination, the wraps were found to persist on the surface of all orbital implants, with little histologic evidence of inflammation localized to the acellular dermis.

CONCLUSIONS

Acellular dermis wraps support fibrovascularization of both HA and PP orbital implants. Additionally, acellular dermis does not incite significant inflammation in association with HA and PP orbital implants and can persist in situ for at least 12 weeks after surgery.