Original Investigation
Management of Porous Orbital Implants Requiring Explantation: A Clinical and Histopathological Study Francesco M. Quaranta-Leoni, M.D.*‡, Caterina Moretti, M.D.*, Sabrina Sposato, M.D.*, Stefano Nardoni, M.D.†, Alessandro Lambiase, M.D.‡, and Stefano Bonini, M.D.‡ *Orbital and Adnexal Service, Department of Ophthalmology, †Department of Pathology, Villa Tiberia Hospital, Via Emilio Praga;and ‡Department of Ophthalmology, Campus Bio-Medico University of Rome, Via Alvaro del Portillo, Roma, Italy
Purpose: To perform a histopathological review of exposed porous orbital implants requiring explantation and to study the clinical outcome of replacement of the exposed implant with an autologous dermis-fat graft. Methods: Case series. Analysis of the clinical charts of 25 patients (age 5 to 62 years) who were submitted to explantation of exposed hydroxyapatite orbital implants, followed by simultaneous replacement with a dermis-fat graft by 1 oculoplastic surgeon between 2000 and 2011. A histopathological and microbiological evaluation of implant sections was performed. This study adheres to the principles outlined in the Declaration of Helsinki. Results: Microbiological examination showed the presence of Gram-positive cocci infection in 59% of the patients. Histopathological examination showed the presence of a chronic inflammatory infiltrate in 22 of the implants (88%) and significantly reduced fibrovascular colonization of the implant in all patients. Conclusions: The reduction of fibrovascular ingrowth resulted in poor integration of the implant in the eye socket. The exposure allowed bacterial colonization of the implant, causing a chronic inflammatory infiltrate. A dermis-fat graft at the same time of explantation can be considered a suitable surgical option in both adults and children: only minor complications may occur, and cosmetic results are satisfactory. (Ophthal Plast Reconstr Surg 2014;30:132–136)
P
orous orbital implants (hydroxyapatite, bioceramics, porous polyethylene) are commonly used following evisceration or enucleation surgery.1 Tissue ingrowth within these implants may offer some potential advantages including: improved motility (if a coupling post is used), reduced migration, and theoretically a reduced infection rate.1–3 Numerous complications have been reported over the years and include culture positive discharge, conjunctival dehiscence, infection, pyogenic granuloma formation, peg-related problems and exposure, which seems to be the most frequent problem.4–6 Small exposures can be treated with various grafts, while large exposures may lead to infection and require removal of the implant.5 The incidence of exposure may be related to the Accepted for publication August 30, 2013. The authors have no financial or conflicts of interest to disclose. Address correspondence and reprint requests to Francesco M. QuarantaLeoni, M.D., University Campus Bio-Medico of Rome, Via Archimede 20100197, Roma, Italy. E-mail: [email protected] DOI: 10.1097/IOP.0000000000000028
132
type of surgery, implant material, size of the implant, tissue ingrowth, coating material, and the rough surface of the porous implant itself.7 The aim of this study was to examine the clinical outcome of patients with exposed porous orbital implants where explantation surgery was selected, followed by simultaneous replacement with an autologous dermis-fat graft. A histopathological review of the explanted orbital implants was also carried out.
MATERIALS AND METHODS This was a single-institution, retrospective, interventional study approved by the institutional review board, with all research adhering to the principles outlined in the Declaration of Helsinki. Written informed consent was obtained from the study participants. The clinical charts of 25 patients referred to the Orbital Clinic of this Department between 2000 and 2011 were analyzed. All patients had exposed porous orbital implants, (primary surgery had been performed elsewhere) and were submitted to explantation of orbital implants and simultaneous replacement with an autologous dermis fat graft. Clinical data included: patient demographics, previous surgery, and signs at presentation; microbiological and histopathological findings were also collected. At time of presentation, all patients showed clinical signs of infection of the exposed implants, and they all had been treated with topical and systemic antibiotic therapy before explantation. None of the patients was affected by autoimmune disease or had been previously submitted to radiation therapy. In all patients, a dermis-fat graft harvested from the patient’s buttock was positioned in the eye socket at the same time of the removal of the exposed implant. Surgery was performed in all cases by the same surgeon (F.M.Q.). The dermis-fat graft was carefully positioned deep in the orbit, in the intraconal space in previously enucleated patients, and inside the scleral remnants in previously eviscerated patients. The fat was sutured to deep tissues of the orbit with 5/0 polyglactin (Vicryl; Ethicon Inc., Johnson & Johnson Co., Somerville, NJ, U.S.A.) sutures, and the dermis was sutured to the Tenon’s capsule and conjunctiva with 6/0 polyglactin (Vicryl; Ethicon Inc.) sutures. A conformer was left in place, and the eye was kept closed for 5 days. Following surgery, all patients were treated with topical and systemic antibiotic therapy. An ophthalmologist performed slit lamp examination to evaluate signs of infection, early necrosis, and morphology of the socket at each follow-up examination (after 5 days, after 10 days, after a month, and every 3 months). The duration of follow up was between 9 and 110 months. In all cases, a microbiological and histopathological evaluation was performed. Following removal, all the orbital implants were fixed in 10% neutral buffered formalin, processed in alcohols and xylene and embedded in paraffin wax. The specimens were decalcified (Biodec R by Bio Optica) to be cut for staining.
Ophthal Plast Reconstr Surg, Vol. 30, No. 2, 2014
Ophthal Plast Reconstr Surg, Vol. 30, No. 2, 2014
Porous Orbital Implants Requiring Explantation
Three-micrometer sections were stained with hematoxylin and eosin to evaluate the presence of inflammation. Immunohistochemical staining with anti-CD34 monoclonal antibody was carried out to assess the presence of fibrovascular growth in the exposed implant.
RESULTS Demographic and clinical features of 25 patients included in the study are summarized in Tables 1 and 2. Primary surgery was enucleation in 17 patients (68%) and evisceration in 8 patients (32%). The average age of patients undergoing
TABLE 1. Demographic characteristics of patients Type of surgery Enucleation
Evisceration
Characteristics
(N = 17)
(N = 8)
Age (average/range) Gender (M:F) Etiology: Trauma Tumor Pan/endophthalmitis Phthisis bulbi Retinal detachment
36(5–62) 9:8
35(19–60) 5:3
7 8 2 — —
2 — — 4 2
TABLE 2. Main clinical features of patients Type of surgery Enucleation
Evisceration
(N = 17)
(N = 8)
Hydroxyapatite
Hydroxyapatite
1–48 mo 17 2
3–72 mo 8 0
2 1 2 0 0
0 0 1 0 0
Characteristics Implant type Time from implant to exposure (range) Infection Tissues necrosi Systemic diseases associated Cardiovascular Tumor Diabetes Radiation therapy Others
enucleation was 36 years, with a range from 5 to 62 years and a ratio M:F of 9:8; the average age of patients undergoing evisceration was 35 years, with a range from 19 to 60 years and a ratio M:F of 5:3. The most frequent cause of enucleation was intraocular tumors, (47.06%; 4 patients with retinoblastoma, 4 patients with choroidal malignant melanoma), while the most frequent cause of evisceration was phthisis bulbi (50%) (Table 1). All patients eviscerated had been treated with unwrapped hydroxyapatite orbital implants. Of the 17 patients enucleated, 5 (29.4%) had scleral coated implants, 10 patients (58.8%) had polyglactin mesh wrapped implants, and 2 patients (11.7%) had implants wrapped with bovine pericardium. Only the 5 patients with scleral wrapped implants showed scleral melting (n = 3) or tissue necrosis (n = 2). The interval from primary surgery to onset of symptoms ranged from 0 to 13 months. Eight patients (32%) had already been submitted to surgery in other institutions for revision of the implant exposure: 3 patients had been submitted to hard palate grafts, 2 patients had scleral grafts, 1 had a conjunctival graft taken from the contralateral eye, and 2 had been submitted to grafts with bovine pericardium. In all these patients, exposure had recurred after 1 to 72 months following surgery (Table 2). All patients included in this study had a synthetic hydroxyapatite orbital implant (diameter range 16–22 mm), signs of infection associated with chronic secretion, and large exposure of implant (>5 mm) (Fig. 1A,B). The exposure was mainly located in the medial area of the conjunctiva. The main symptoms and signs were discharge and secretion in 25 patients (100%), irritation and pain in 23 patients (92%), occasional bleeding in 8 patients (32%), and tissue necrosis in 2 patients (8%). Microbiological examination showed the presence of Grampositive cocci infection in 59% of the patients (Fig. 2). No signs of infection were detected in the other 41% of the patients. Histopathological examination showed the presence of a chronic inflammatory infiltrate with presence of giant cells with inclusion bodies in 22 of the examined implants (88%) (Fig. 3A,B) and a significantly reduced fibrovascular colonization of the implant in all the patients (Fig. 3C,D) (Table 3). During the follow up, none of the patients had necrosis of the dermis-fat graft. In 24 of 25 patients, the volume and fornices were appropriate, and only 4 patients requested lower eyelid and/or ptosis surgery following fitting of the definitive prosthesis. None of them had further orbital surgery (Fig. 4). In 1 patient, previously enucleated for melanoma and subsequently submitted to implant removal and dermis-fat graft, a progressive depletion of the size of the graft
FIG. 1. A, B, Implant exposures.
© 2014 The American Society of Ophthalmic Plastic and Reconstructive Surgery, Inc.
133
Ophthal Plast Reconstr Surg, Vol. 30, No. 2, 2014
F. M. Quaranta-Leoni et al.
FIG. 2. (×40) Microbiological examination (Gram-positive cocci). with significant volume loss was observed. The patient refused additional surgery.
DISCUSSION At present, the most commonly used orbital implants are porous implants, including hydroxyapatite, porous polyethylene, and aluminium oxide.8 According to a review study that examined pooled data from published articles between 1989 and 2004, the exposure rate of hydroxyapatite implants is 4.9%, as opposed to exposure rate of 8.1% of porous polyethylene implants, the difference probably due to the higher number of complications associated with uncoated porous polyethylene implants.7 In another study, Ramey et al.9 showed that porous polyethylene and aluminum oxide implants are associated with higher exposure rates and higher overall complication rates compared with hydroxyapatite implants. Jung et al.10 showed instead that, using porous polyethylene resulted in similar surgical outcomes, in terms of the types and frequencies of complications, as other kinds of porous orbital implants. Careful selection of surgical technique, implant type, and size may help to reduce the risk of severe complications (e.g., exposures), and adequate wrapping has been advocated as being effective in preventing implant exposure following enucleation.11–13 Soaking porous implants in antibiotic solution at the time of implantation is also recommended to promote fibrovascular ingrowth and reduce the risk of infection.14,15 Although many of the treatment options advocated for management of orbital implant exposure may be useful in some cases, exposures still occur, and it may be necessary to remove the implant later.16,17 According to Sagoo and Rose18 and their “cactus syndrome” theory, one of the major causes of exposure would be an incorrect surgical technique: a rough-surfaced
implant forced in the orbit at surgery may drag the fat down the socket, and a late tissue restitution may occur following surgery. The high failure rate after attempted repair of exposures could be related to the fact that the underlying cause, that is the anterior migration of the implant, remains untreated. According to Custer and Trinkaus,7 spontaneous healing takes place in a small percentage of cases (13%), while for larger exposures, the use of vascularized flaps of conjunctiva is the most effective surgical technique. However, in the series described, 29% (42 of 145) of exposed implants were removed.7 In 8 of these patients, additional surgery had been performed by other surgeons to treat the implant exposure, but explantation was later performed by the authors in all cases, due to either recurrence of a large exposure or to infection of the implant. These findings suggest that anterior exposure may allow bacterial colonization and a subsequent heavy inflammatory infiltrate. Adequate tissue ingrowth through the pores of the implant allows biointegration, reducing the risk of exposure and infection;19 poor tissue ingrowth may limit the penetration of topical or systemic antibiotic therapy, leading to the necessity for explantation. In line with data present in literature, the presence of active infection was found, subsequently confirmed by microbiological examination. This examination has revealed the presence of Gram-positive cocci that could suggest a colonization of the implant. Chuo et al.8 had already shown that the anterior exposure of porous polyethylene implant allows penetration of bacteria and subsequent colonization of the implant. Jordan et al.20 detected the presence of implant exposure in 9 of 13 patients who showed symptoms and signs of infection of the implant, demonstrating that infection may be a direct result of implant exposure. In this series, the implants that were removed showed a reduction of fibrovascular ingrowth with associated inflammatory infiltrate tissue, consisting predominantly of multinucleated giant cells, in line with what observed by Klapper and Rosner.21,22 It is possible to hypothesize that the reduced fibrovascular colonization had resulted in poor integration of the implant in the orbital cavity with subsequent exposure. The exposure allowed the bacterial colonization of the implant, causing a chronic inflammatory infiltrate with presence of multinucleated giant cells. The poor fibrovascular ingrowth may have limited the penetration of systemic antibiotics, with the consequent need for explantation. Chuo et al.8 have demonstrated in their study that in 16 of 18 patients with exposed orbital implants, there was
Management of Porous Orbital Implants Requiring Explantation: A Clinical and Histopathological Study Francesco M. Quaranta-Leoni, M.D.*‡, Caterina Moretti, M.D.*, Sabrina Sposato, M.D.*, Stefano Nardoni, M.D.†, Alessandro Lambiase, M.D.‡, and Stefano Bonini, M.D.‡ *Orbital and Adnexal Service, Department of Ophthalmology, †Department of Pathology, Villa Tiberia Hospital, Via Emilio Praga;and ‡Department of Ophthalmology, Campus Bio-Medico University of Rome, Via Alvaro del Portillo, Roma, Italy
Purpose: To perform a histopathological review of exposed porous orbital implants requiring explantation and to study the clinical outcome of replacement of the exposed implant with an autologous dermis-fat graft. Methods: Case series. Analysis of the clinical charts of 25 patients (age 5 to 62 years) who were submitted to explantation of exposed hydroxyapatite orbital implants, followed by simultaneous replacement with a dermis-fat graft by 1 oculoplastic surgeon between 2000 and 2011. A histopathological and microbiological evaluation of implant sections was performed. This study adheres to the principles outlined in the Declaration of Helsinki. Results: Microbiological examination showed the presence of Gram-positive cocci infection in 59% of the patients. Histopathological examination showed the presence of a chronic inflammatory infiltrate in 22 of the implants (88%) and significantly reduced fibrovascular colonization of the implant in all patients. Conclusions: The reduction of fibrovascular ingrowth resulted in poor integration of the implant in the eye socket. The exposure allowed bacterial colonization of the implant, causing a chronic inflammatory infiltrate. A dermis-fat graft at the same time of explantation can be considered a suitable surgical option in both adults and children: only minor complications may occur, and cosmetic results are satisfactory. (Ophthal Plast Reconstr Surg 2014;30:132–136)
P
orous orbital implants (hydroxyapatite, bioceramics, porous polyethylene) are commonly used following evisceration or enucleation surgery.1 Tissue ingrowth within these implants may offer some potential advantages including: improved motility (if a coupling post is used), reduced migration, and theoretically a reduced infection rate.1–3 Numerous complications have been reported over the years and include culture positive discharge, conjunctival dehiscence, infection, pyogenic granuloma formation, peg-related problems and exposure, which seems to be the most frequent problem.4–6 Small exposures can be treated with various grafts, while large exposures may lead to infection and require removal of the implant.5 The incidence of exposure may be related to the Accepted for publication August 30, 2013. The authors have no financial or conflicts of interest to disclose. Address correspondence and reprint requests to Francesco M. QuarantaLeoni, M.D., University Campus Bio-Medico of Rome, Via Archimede 20100197, Roma, Italy. E-mail: [email protected] DOI: 10.1097/IOP.0000000000000028
132
type of surgery, implant material, size of the implant, tissue ingrowth, coating material, and the rough surface of the porous implant itself.7 The aim of this study was to examine the clinical outcome of patients with exposed porous orbital implants where explantation surgery was selected, followed by simultaneous replacement with an autologous dermis-fat graft. A histopathological review of the explanted orbital implants was also carried out.
MATERIALS AND METHODS This was a single-institution, retrospective, interventional study approved by the institutional review board, with all research adhering to the principles outlined in the Declaration of Helsinki. Written informed consent was obtained from the study participants. The clinical charts of 25 patients referred to the Orbital Clinic of this Department between 2000 and 2011 were analyzed. All patients had exposed porous orbital implants, (primary surgery had been performed elsewhere) and were submitted to explantation of orbital implants and simultaneous replacement with an autologous dermis fat graft. Clinical data included: patient demographics, previous surgery, and signs at presentation; microbiological and histopathological findings were also collected. At time of presentation, all patients showed clinical signs of infection of the exposed implants, and they all had been treated with topical and systemic antibiotic therapy before explantation. None of the patients was affected by autoimmune disease or had been previously submitted to radiation therapy. In all patients, a dermis-fat graft harvested from the patient’s buttock was positioned in the eye socket at the same time of the removal of the exposed implant. Surgery was performed in all cases by the same surgeon (F.M.Q.). The dermis-fat graft was carefully positioned deep in the orbit, in the intraconal space in previously enucleated patients, and inside the scleral remnants in previously eviscerated patients. The fat was sutured to deep tissues of the orbit with 5/0 polyglactin (Vicryl; Ethicon Inc., Johnson & Johnson Co., Somerville, NJ, U.S.A.) sutures, and the dermis was sutured to the Tenon’s capsule and conjunctiva with 6/0 polyglactin (Vicryl; Ethicon Inc.) sutures. A conformer was left in place, and the eye was kept closed for 5 days. Following surgery, all patients were treated with topical and systemic antibiotic therapy. An ophthalmologist performed slit lamp examination to evaluate signs of infection, early necrosis, and morphology of the socket at each follow-up examination (after 5 days, after 10 days, after a month, and every 3 months). The duration of follow up was between 9 and 110 months. In all cases, a microbiological and histopathological evaluation was performed. Following removal, all the orbital implants were fixed in 10% neutral buffered formalin, processed in alcohols and xylene and embedded in paraffin wax. The specimens were decalcified (Biodec R by Bio Optica) to be cut for staining.
Ophthal Plast Reconstr Surg, Vol. 30, No. 2, 2014
Ophthal Plast Reconstr Surg, Vol. 30, No. 2, 2014
Porous Orbital Implants Requiring Explantation
Three-micrometer sections were stained with hematoxylin and eosin to evaluate the presence of inflammation. Immunohistochemical staining with anti-CD34 monoclonal antibody was carried out to assess the presence of fibrovascular growth in the exposed implant.
RESULTS Demographic and clinical features of 25 patients included in the study are summarized in Tables 1 and 2. Primary surgery was enucleation in 17 patients (68%) and evisceration in 8 patients (32%). The average age of patients undergoing
TABLE 1. Demographic characteristics of patients Type of surgery Enucleation
Evisceration
Characteristics
(N = 17)
(N = 8)
Age (average/range) Gender (M:F) Etiology: Trauma Tumor Pan/endophthalmitis Phthisis bulbi Retinal detachment
36(5–62) 9:8
35(19–60) 5:3
7 8 2 — —
2 — — 4 2
TABLE 2. Main clinical features of patients Type of surgery Enucleation
Evisceration
(N = 17)
(N = 8)
Hydroxyapatite
Hydroxyapatite
1–48 mo 17 2
3–72 mo 8 0
2 1 2 0 0
0 0 1 0 0
Characteristics Implant type Time from implant to exposure (range) Infection Tissues necrosi Systemic diseases associated Cardiovascular Tumor Diabetes Radiation therapy Others
enucleation was 36 years, with a range from 5 to 62 years and a ratio M:F of 9:8; the average age of patients undergoing evisceration was 35 years, with a range from 19 to 60 years and a ratio M:F of 5:3. The most frequent cause of enucleation was intraocular tumors, (47.06%; 4 patients with retinoblastoma, 4 patients with choroidal malignant melanoma), while the most frequent cause of evisceration was phthisis bulbi (50%) (Table 1). All patients eviscerated had been treated with unwrapped hydroxyapatite orbital implants. Of the 17 patients enucleated, 5 (29.4%) had scleral coated implants, 10 patients (58.8%) had polyglactin mesh wrapped implants, and 2 patients (11.7%) had implants wrapped with bovine pericardium. Only the 5 patients with scleral wrapped implants showed scleral melting (n = 3) or tissue necrosis (n = 2). The interval from primary surgery to onset of symptoms ranged from 0 to 13 months. Eight patients (32%) had already been submitted to surgery in other institutions for revision of the implant exposure: 3 patients had been submitted to hard palate grafts, 2 patients had scleral grafts, 1 had a conjunctival graft taken from the contralateral eye, and 2 had been submitted to grafts with bovine pericardium. In all these patients, exposure had recurred after 1 to 72 months following surgery (Table 2). All patients included in this study had a synthetic hydroxyapatite orbital implant (diameter range 16–22 mm), signs of infection associated with chronic secretion, and large exposure of implant (>5 mm) (Fig. 1A,B). The exposure was mainly located in the medial area of the conjunctiva. The main symptoms and signs were discharge and secretion in 25 patients (100%), irritation and pain in 23 patients (92%), occasional bleeding in 8 patients (32%), and tissue necrosis in 2 patients (8%). Microbiological examination showed the presence of Grampositive cocci infection in 59% of the patients (Fig. 2). No signs of infection were detected in the other 41% of the patients. Histopathological examination showed the presence of a chronic inflammatory infiltrate with presence of giant cells with inclusion bodies in 22 of the examined implants (88%) (Fig. 3A,B) and a significantly reduced fibrovascular colonization of the implant in all the patients (Fig. 3C,D) (Table 3). During the follow up, none of the patients had necrosis of the dermis-fat graft. In 24 of 25 patients, the volume and fornices were appropriate, and only 4 patients requested lower eyelid and/or ptosis surgery following fitting of the definitive prosthesis. None of them had further orbital surgery (Fig. 4). In 1 patient, previously enucleated for melanoma and subsequently submitted to implant removal and dermis-fat graft, a progressive depletion of the size of the graft
FIG. 1. A, B, Implant exposures.
© 2014 The American Society of Ophthalmic Plastic and Reconstructive Surgery, Inc.
133
Ophthal Plast Reconstr Surg, Vol. 30, No. 2, 2014
F. M. Quaranta-Leoni et al.
FIG. 2. (×40) Microbiological examination (Gram-positive cocci). with significant volume loss was observed. The patient refused additional surgery.
DISCUSSION At present, the most commonly used orbital implants are porous implants, including hydroxyapatite, porous polyethylene, and aluminium oxide.8 According to a review study that examined pooled data from published articles between 1989 and 2004, the exposure rate of hydroxyapatite implants is 4.9%, as opposed to exposure rate of 8.1% of porous polyethylene implants, the difference probably due to the higher number of complications associated with uncoated porous polyethylene implants.7 In another study, Ramey et al.9 showed that porous polyethylene and aluminum oxide implants are associated with higher exposure rates and higher overall complication rates compared with hydroxyapatite implants. Jung et al.10 showed instead that, using porous polyethylene resulted in similar surgical outcomes, in terms of the types and frequencies of complications, as other kinds of porous orbital implants. Careful selection of surgical technique, implant type, and size may help to reduce the risk of severe complications (e.g., exposures), and adequate wrapping has been advocated as being effective in preventing implant exposure following enucleation.11–13 Soaking porous implants in antibiotic solution at the time of implantation is also recommended to promote fibrovascular ingrowth and reduce the risk of infection.14,15 Although many of the treatment options advocated for management of orbital implant exposure may be useful in some cases, exposures still occur, and it may be necessary to remove the implant later.16,17 According to Sagoo and Rose18 and their “cactus syndrome” theory, one of the major causes of exposure would be an incorrect surgical technique: a rough-surfaced
implant forced in the orbit at surgery may drag the fat down the socket, and a late tissue restitution may occur following surgery. The high failure rate after attempted repair of exposures could be related to the fact that the underlying cause, that is the anterior migration of the implant, remains untreated. According to Custer and Trinkaus,7 spontaneous healing takes place in a small percentage of cases (13%), while for larger exposures, the use of vascularized flaps of conjunctiva is the most effective surgical technique. However, in the series described, 29% (42 of 145) of exposed implants were removed.7 In 8 of these patients, additional surgery had been performed by other surgeons to treat the implant exposure, but explantation was later performed by the authors in all cases, due to either recurrence of a large exposure or to infection of the implant. These findings suggest that anterior exposure may allow bacterial colonization and a subsequent heavy inflammatory infiltrate. Adequate tissue ingrowth through the pores of the implant allows biointegration, reducing the risk of exposure and infection;19 poor tissue ingrowth may limit the penetration of topical or systemic antibiotic therapy, leading to the necessity for explantation. In line with data present in literature, the presence of active infection was found, subsequently confirmed by microbiological examination. This examination has revealed the presence of Gram-positive cocci that could suggest a colonization of the implant. Chuo et al.8 had already shown that the anterior exposure of porous polyethylene implant allows penetration of bacteria and subsequent colonization of the implant. Jordan et al.20 detected the presence of implant exposure in 9 of 13 patients who showed symptoms and signs of infection of the implant, demonstrating that infection may be a direct result of implant exposure. In this series, the implants that were removed showed a reduction of fibrovascular ingrowth with associated inflammatory infiltrate tissue, consisting predominantly of multinucleated giant cells, in line with what observed by Klapper and Rosner.21,22 It is possible to hypothesize that the reduced fibrovascular colonization had resulted in poor integration of the implant in the orbital cavity with subsequent exposure. The exposure allowed the bacterial colonization of the implant, causing a chronic inflammatory infiltrate with presence of multinucleated giant cells. The poor fibrovascular ingrowth may have limited the penetration of systemic antibiotics, with the consequent need for explantation. Chuo et al.8 have demonstrated in their study that in 16 of 18 patients with exposed orbital implants, there was
