Search tips
Search criteria

Results 1-25 (935633)

Clipboard (0)

Related Articles

1.  The Survival of Freely Grafted Orbital Fat on Porous Polyethylene Orbital Implants in the Rabbit 
To investigate the long term survival of orbital fat grafted on a Medpor® implant as a method of preventing porous polyethylene orbital implant (Medpor®) exposure in anophthalmic sockets.
In one orbit in each of 8 rabbits, a small amount of retrobulbar orbital fat was grafted between the anterior surface of the Medpor® implant and overlying conjunctiva, during the enucleation and Medpor® implantation procedure. Two rabbits were sacrificed at 2, 4, 8 and 12 weeks postoperatively and grafted orbital fats were examined by light microscopy.
Grafted orbital fat was well-maintained at 2 and 4 weeks, postoperatively. However, fat amounts were significantly reduced at 8 weeks, and viable fat was barely visible at 12 weeks.
In rabbits, orbital fat grafted on Medpor® implants was gradually resorbed, and the fat-occupied volume was not maintained.
PMCID: PMC2908836  PMID: 17004626
Exposure; Medpor®; Orbital fat
2.  High density porous polyethylene material (Medpor) as an unwrapped orbital implant 
Objective: To introduce the clinical effect among patients who received an unwrapped orbital implant with high density porous polyethylene material (Medpor) after enucleation or evisceration. Methods: Retrospective analysis of a series of 302 patients with anophthalmia who underwent placement of an unwrapped high density porous polyethylene orbital implant. We compared the patients (n=180) who accepted primary implant placement with those (n=122) who accepted secondary implant placement. Parameters evaluated included: age at time of surgery, date of surgery, sex, implant type and size, surgery type, the surgical procedure and technique performed, and complications. Results: The time of follow-up ranged from 2.0 to 58.0 months (mean 32.5 months). A total of 5 of 302 (1.66%) cases had documented postoperative complications. The following problems were noted after surgery: implant exposure, 3 patients (0.99%); implant removed due to orbital infection, 1 patient (0.34%); ptosis, 1 patient (0.34%). There were no significant complications observed in other 297 cases and all implants showed good orbital motility. The clinical effect of primary implant placement is better than that of secondary placement. Conclusion: High density porous polyethylene material can be used successfully as an unwrapped orbital implant in anopthalmic socket surgery with minimal complications. The material is well tolerated, nonantigenic and has low rate of infection and migration.
PMCID: PMC1533749  PMID: 16845724
Orbital implants; High density porous polyethylene; Correction of orbital abnormality
3.  Autogenous temporalis fascia patch graft for porous polyethylene (Medpor) sphere orbital implant exposure 
Background: Temporalis fascia has been recommended for hydroxyapatite sphere exposure. The aim of this study was to identify potential risk factors for exposure of porous polyethylene (Medpor) sphere implants and evaluate the use of autogenous temporalis fascia as a patch graft for exposure.
Methods: A retrospective review of consecutive cases of porous polyethylene sphere orbital implant exposure.
Results: Five cases presented between May 2000 and October 2001 (three males, two females; mean age 44.5 years). Three had enucleation (two with primary implants) and two had evisceration (one with primary implant). Exposure occurred in one primary, two secondary, and two replacement implants. Orbital implant diameter was 20 mm in four cases and 16 mm in one case (contracted socket). The mean time from implantation to exposure was 23 months (range 0.7–42.6). Three patients had secondary motility peg placement before exposure. The average time from last procedure (sphere implant or peg insertion) to exposure was 3 months (range 0.7–12.6). Four patients required surgical intervention, of which three needed more than one procedure. Autogenous temporalis fascia grafting successfully closed the defect without re-exposure in three of these four patients. The grafts were left bare in three patients, with a mean time to conjunctivalise of 2.4 months (range 1.6–3.2).
Conclusions: Exposed porous polyethylene sphere implants were treated successfully with autogenous temporalis fascia graft in three of four patients. This technique is useful, the graft easy to harvest, and did not lead to prolonged socket inflammation, infection, or extrusion.
PMCID: PMC1772235  PMID: 15205243
porous polyethylene sphere implants; exposure; temporalis fascia patch graft
4.  Amniotic membrane transplantation for porous sphere orbital implant exposure 
Objective: This study is aimed at describing the clinical outcome of amniotic membrane transplantation for exposure of porous sphere implants. Methods: A retrospective review of consecutive cases of porous sphere orbital implant exposure was carried out. Eight cases were presented between May 2004 and Oct. 2006 (5 males, 3 females; mean age 44.5 years). Six had enucleation and two had evisceration. Exposure occurred in two primary and six secondary. Orbital implant diameter was 22 mm in seven cases and 20 mm in one case. Six patients are with hydroxyapatite and two with high-density porous polyethylene (Medpor) orbital implants. The mean time from implantation to exposure was 1.1 months (range 0.8~2 months). All patients required surgical intervention. Results: The time of follow-up ranged from 3.0 to 28.0 months (mean 16.5 months). Amniotic membrane grafting successfully closed the defect without re-exposure in all of these patients. The grafts were left bare with a mean time to conjunctiva of about 1 month (range 0.8~1.5 months). Conclusion: Exposed porous sphere implants were treated successfully with amniotic membrane graft in all of patients. The graft is easy to harvest. This technique is useful, dose not lead to prolonged socket inflammation and infection, and it is valuable application extensively.
PMCID: PMC1963426  PMID: 17726741
Amniotic membrane transplantation; Orbital implants; Exposure
5.  The Results of Evisceration with Primary Porous Implant Placement in Patients with Endophthalmitis 
To assess the results and long-term prognosis of evisceration with primary porous implant placement in patients with endophthalmitis.
A retrospective study was conducted to review the files of 27 patients (29 eyes) with endophthalmitis who underwent evisceration with primary porous implant placement from January 1997 to December 2007 at St. Mary's Hospital and Kangnam St. Mary's Hospital. The mean follow-up period was 12.24 months (range, 3 to 89 months) and the mean age of the patients was 63.6 years (range, 33 to 89 years).
During the surgical procedure, primary implant placement was successfully completed, and any postoperative infection or inflammation rapidly resolved in all 27 patients (29 eyes). One of two porous implant materials was used. Hydroxyapatite was inserted in 14 eyes and Medpor was inserted in 15 eyes. Delayed implant exposure was noted in 1 eye, which was treated by inserting a hydroxyapatite implant 18 months after the first surgery. This was well treated by a preserved scleral graft. Implant infection was noted in 1 other eye at 20 days after the first surgery. All other minor complications healed without sequelae.
Evisceration with primary porous implant placement as the treatment for recalcitrant endophthalmitis resulted in rapid resolution of any infection and inflammation. Implant exposure and infection occurred in only 2 eyes, and these problems were well treated without long-term sequelae. Therefore, evisceration with primary porous implant placement is a treatment option for patients with endophthalmitis.
PMCID: PMC2955270  PMID: 21052507
Endophthalmitis; Evisceration; Porous implant
6.  The use of porous polyethylene (Medpor) lower eyelid spacers in lid heightening and stabilisation 
The British Journal of Ophthalmology  2004;88(9):1197-1200.
Background/aims: The management of lower eyelid retraction can be challenging, and established techniques to correct it are not always successful. Previous reports have suggested a role for the ultrathin high density porous polyethylene lower eyelid spacer (Medpor LES) in such patients. The authors report the experience of three surgeons implanting Medpor LES over 1 year, and ascertain whether such implants are a safe and effective alternative to autogenous spacers.
Methods: A prospective, interventional, non-comparative case series of consecutive patients. Surgical indications for Medpor LES were noted. Preoperative and postoperative lower marginal reflex distance (L-MRD), vertical palpebral aperture (PA), lagophthalmos, and scleral show inferior to the limbus (LSS) were recorded, together with major and minor complications.
Results: 32 patients (35 eyelids) had a Medpor LES inserted, 22/32 under local anaesthetic, and nine with adjunctive procedures. Mean follow up was 22 months (range 15–28 months). The Medpor LES was effective in reducing the palpebral aperture (p<0.001) and lagophthalmos (p = 0.04) and raising the lower eyelid height by reducing both L-MRD (p  =  0.006) and LSS (p<0.001). However there were major complications in 7/32 patients and minor complications in 8/32, most requiring further surgery. Final outcome was good in 24/35 eyelids and satisfactory in 5/35.
Conclusions: Despite a good or satisfactory final outcome in the majority of patients, the value of this technique is limited by complications, and should be reserved for those unsuitable for safer techniques.
PMCID: PMC1772304  PMID: 15317715
Medpor; porous polyethylene; lower eyelid spacer; implant
7.  UK national survey of enucleation, evisceration and orbital implant trends 
To evaluate current clinical practice in the UK in the management of the anophthalmic socket; choice of enucleation, evisceration, type of orbital implant, wrap, motility pegging and complications.
All consultant ophthalmologists in the UK were surveyed by postal questionnaire. Questions included their practice subspecialty and number of enucleations and eviscerations performed in 2003. Specific questions addressed choice of implant, wrap, motility pegging and complications.
456/896 (51%) consultants responded, of which 162 (35%) had a specific interest in oculoplastics, lacrimal, orbits or oncology. Only 243/456 (53%) did enucleations or eviscerations. 92% inserted an orbital implant after primary enucleation, 69% after non‐endophthalmitis evisceration, whereas only 43% did so after evisceration for endophthalmitis (50% as a delayed procedure). 55% used porous orbital implants (porous polyethylene, hydroxyapatite or alumina) as their first choice and 42% used acrylic. Most implants inserted were spherical, sized 18–20 mm in diameter. 57% wrapped the implant after enucleation, using salvaged autogenous sclera (20%), donor sclera (28%) and synthetic Vicryl or Mersilene mesh (42%). A minority (7%) placed motility pegs in selected cases, usually as a secondary procedure. 14% of respondents reported implant exposure for each type of procedure and extrusion was reported by 4% after enucleation and 3% after evisceration.
This survey highlights contemporary anophthalmic socket practice in the UK. Most surgeons use porous orbital implants with a synthetic wrap after enucleation and only few perform motility pegging.
PMCID: PMC1954760  PMID: 17151061
8.  Long-term Surgical Outcomes of the Multi-purpose Conical Porous Synthetic Orbital Implant 
We present clinical results of the use of the multipurpose conical porous synthetic orbital implant (MCOI) in surgical procedures of evisceration, enucleation, and secondary enucleation in ophthalmology patients.
A retrospective review was performed of 59 eyes in which conical implants were used, including 36 cases of eviscerations, 11 enucleations, and 9 secondary enucleations. In all of the cases, the follow-up period was greater than six months between 2004 and 2013. The results focus on documenting surgical findings, as well as postoperative complications among patients.
Superior sulcus deformities were found in six eyes (10.2% of conical implant patients), and two eyes received additional surgical interventions to correct the deformities (3.4%). Blepharoptosis was found in four eyes (6.8%), two of which received upper eyelid blepharoplasty (3.4%). Fornix shortening was reported in only one eye (1.7%). Forty-one eyes had a satisfactory cosmetic appearance after the final prosthetic fitting of conical implants (69.5%). The most frequent postoperative complication was orbital implant exposure, which seemed to occur when the preoperative status of the conjunctiva, Tenon's capsule, and sclera preservation were poor in the eyes of the patients.
There was a lower incidence of blepharoptosis and fornix shortening with the MCOI in comparison to spherical implants, while the incidence of orbital implant exposure was similar with the MCOI in comparison to other types of orbital implants. In addition, the MCOI may have advantages with respect to postoperative cosmetic outcomes.
PMCID: PMC4595254  PMID: 26457034
Eye enucleation; Eye evisceration; Orbital implants; Prosthesis implantation
9.  Efficacy of Iliac Crest vs. Medpor in Orbital Floor Reconstruction 
The present study is to compare the effectiveness of iliac crest graft and medpor implant, for repairing traumatic orbital floor defects.
Materials and methods
A total of 20 patients were included in the study. Autogenous iliac crest graft and medpor implant was used in 10 patients of the each group. Patients were evaluated for the presence or absence of diplopia, enophthalmos, infraorbital nerve paresthesia, and ocular motility disorders. Surgical indications for orbital exploration included entrapment of orbital tissues, large orbital defect (greater than 50% of the orbital floor or more than 8 mm), or orbital floor defects with involvement of other zygomaticofrontal complex fractures.
All patients were successfully treated by restoration of the orbital wall continuity. Follow-up was done at 1–12 weeks. One patient had postoperative infection. There was no graft extrusion.
Both the groups showed satisfactory results, but group II was better than group I, as there was no donor site morbidity. Porous polyethylene (Medpor) is a biocompatible and high-density polyethylene implant. It is well tolerated by surrounding tissue, and its porous structure is rapidly infiltrated by host tissue. It is a highly stable and somewhat flexible porous alloplast that has rapid tissue in growth into its pores.
PMCID: PMC3244104  PMID: 22190772
Medpor; Orbit; Iliac crest; Trauma
10.  Orbital Floor Fractures: A Retrospective Review of 45 Cases at a Tertiary Health Care Center 
The purpose of this retrospective study was to investigate treatment options for orbital floor fractures at a Level 1 Trauma Center in Southern California. A review of 45 cases of isolated orbital floor fractures treated at the University of California at Irvine between February 2004 and April 2007 was done. Patients were retrospectively analyzed for gender, age, mechanism of injury, associated facial injuries, presenting symptoms, method of treatment, and postoperative complications. Thirty-six male patients and nine female patients were treated. Motor vehicle collision (26/45) was the most common cause of injury, and the mean age of the patients was 35.5 years (range: 15–81 years). Ecchymosis surrounding the orbital tissue was the most common presentation (38/45). Diplopia was present in 8 of 45 patients, with 1 patient requiring urgent decompression for retrobulbar hematoma. Forty-three patients underwent surgical repair; 40 underwent transconjunctival approach with lateral canthotomy; 17 underwent reconstruction with porous polyethylene Medpor (Porex Surgical, Inc., College Park, GA.); and 26 underwent reconstruction with a titanium mesh plate. Immediate postoperative complications included 12 patients with infraorbital numbness, 3 with diplopia, 1 with cellulitis, and 1 with ectropion with a subcilliary approach. Average timing of surgery of our study was 4.94 days (range, 1–20 days). Orbital floor fracture management has changed significantly over the past few decades with the introduction of new internal fixation methods and new materials for reconstructing orbital floor defects. Recommendations for surgical intervention on orbital floor fractures mostly depend on clinical examination and imaging studies. Consequences of inadequate repair of orbital floor fractures can lead to significant facial asymmetry and visual problems. Both porous polyethylene and titanium plates are effective tools for reconstructing the orbital floor. Our review demonstrates that orbital floor fractures can be repaired safely with minimal postoperative complications and confirms that transconjunctival approach to orbital floor is an effective way for exposure and prevention of ectropion that can be seen with other techniques.
PMCID: PMC3052659  PMID: 22110817
Orbital floor fractures; review; treatment options
11.  Remove, rotate, and reimplant: a novel technique for the management of exposed porous anophthalmic implants in eviscerated patients 
Eye  2014;28(5):546-552.
To describe and to evaluate a new and relatively easy technique for porous implant exposure repair.
Eleven patients with exposed porous orbital implants after evisceration were included in this study. Five patients with large exposures (diameter>7 mm) and six patients with small exposures of orbital implants (diameter<7 mm) that persisted despite posterior vaulting of the prosthesis and usage of antibiotics and steroids for more than 6 weeks, underwent revision surgery with the remove-rotate-reimplant technique (3R technique). Negative microbiological culture taken from the exposed socket surface before surgery was the major inclusion criterion. Five patients with insufficient conjunctival tissue also underwent additional mucosa or hard palate grafting of the defect in addition to the remove-rotate-reimplant procedure.
Patients have been followed up for more than 18 months (ranging from 18–30 months). None of them received motility peg insertion after repair. Implant reexposure was detected in one patient during the follow-up period, which was managed by dermis fat grafting with implant removal.
The remove-rotate-reimplant technique is an effective surgical method for repairing exposed porous anophthalmic implants after evisceration with a 90% success in this study. It avoids the removal of the implant from the sclera, which is a traumatic procedure that may lead to the tearing and loss of scleral tissue covering the implant. Saving the porous implant and scleral cover reduces the surgical time and cost.
PMCID: PMC4017112  PMID: 24503727
porous implant exposure; exposed hydroxyapatite implants; implant exposure repair
12.  Use of porous high-density polyethylene grafts in open rhinoplasty: no infectious complication seen in spreader and dorsal grafts 
Head & Face Medicine  2014;10:52.
The aim of this study is to use porous high-density polyethylene grafts (Medpor) in open rhinoplasty and then assess complication rate and aesthetic outcomes.
In a prospective cohort study, we performed open rhinoplasty and employed Medpor as rhinoplasty grafts. Then we compared their complication rate.
In a total of 64 patients, 84 Medpor grafts -38 dorsal grafts, 23 strut grafts, 8 rim grafts, 5 button grafts and 10 spreader grafts – were utilized. Moreover, 5septal perforation repairs with Medpor were performed. The complication rates were 5.3% in dorsal graft (complication in dorsal graft was only movement of implant), 21.7% in strut graft and 25.0% in rim graft. No complication was seen in spreader and button grafts. All 5septal perforation repairs were successfully performed with the same rhinoplasty approach.
Medpor can be used as dorsal and spreader graft in reconstruction of severe nose deformity with lowest complication rate and without infectious complication and extrusion.
PMCID: PMC4533771  PMID: 25534471
Medpor complication; Rhinoplasty; Spreader graft; Dorsal graft
13.  Enucleation and evisceration at a tertiary care hospital in a developing country 
BMC Ophthalmology  2015;15:120.
To analyze the demographics, indications, and surgical outcomes of anophthalmic surgery (enucleation and evisceration) at Jordan University Hospital during a 5-year period.
We conducted a retrospective chart review of patients who had undergone evisceration or enucleation between August 2006 and June 2011. The data collected included age at time of surgery, sex, affected eye, surgical indication, implant size, and postoperative complications.
Anophthalmic surgery was performed for 68 eyes of 67 patients during the study period (42 (62 %) eviscerations and 26 (38 %) enucleations). Forty-three patients (64 %) were men, and 40 (59 %) eyes were right eyes. Trauma was the leading cause for anophthalmic surgery in 40 % of cases followed by a blind painful eye secondary to glaucoma (19 %) in the enucleation group and endophthalmitis (28.6 %) in the evisceration group. The most common anophthalmic surgery complication was wound dehiscence in 11.5 % of patients in the enucleation and 9.5 % in the evisceration groups. The mean and median sizes of the implants for evisceration were 16.6 and 18.0 mm, respectively; for enucleation, both were 20 mm.
Evisceration was the preferred anophthalmic surgery in our series unless contraindicated. Trauma was the most common predisposing factor for evisceration and enucleation in our tertiary care center followed by blind painful eyes and endophthalmitis. The most common complication was wound dehiscence in both groups.
PMCID: PMC4566484  PMID: 26362425
14.  Long-term infectious complications of using porous polyethylene mesh for orbital fracture reconstruction 
Medicine  2016;95(25):e3819.
Porous polyethylene is a widely used implants in orbital reconstruction, on which comprehensive clinical analysis, various treatments, and different prognosis according to specific classification principles on long-term complications have not been reported.
To investigate the new clinical symptoms, intraoperative findings, treatments, and outcomes of complications long period after previous surgery, resulting from the use of porous polyethylene mesh for orbital fracture reconstruction.
A retrospective study was conducted on 21 patients at the Department of Ophthalmology, Shanghai Ninth People's Hospital with orbital complications after orbital fracture reconstruction with porous polyethylene mesh for 4 ± 2.2 years from 2011 to 2013. These data included new clinical symptoms after previous surgery, computerized tomography data, intraoperative findings, treatments, and outcomes.
Data from 21 patients were analyzed in this study. Two patients received conservative treatment, while the other 19 patients underwent surgical approaches. Classification principles for orbital complications after orbital wall defect reconstruction with porous polyethylene mesh were formulated according to patients’ new clinical symptoms, computed tomography (CT), and intraoperative findings after previous surgery. In the last follow-up, 19 patients (90.5%) were cured or improved according to our assessment principle. The follow-up ranged from 3 to 45 months (35 months in average).
According to specific classification for orbital complications resulting from the use of porous polyethylene mesh for orbital fracture reconstruction, various medical treatments should be carried out, and the prognosis may be different.
PMCID: PMC4998305  PMID: 27336867
complication; orbital fracture reconstruction; porous polyethylene
15.  Safety and Biocompatibility of a New High-Density Polyethylene-Based Spherical Integrated Porous Orbital Implant: An Experimental Study in Rabbits 
Journal of Ophthalmology  2015;2015:904096.
Purpose. To evaluate clinically and histologically the safety and biocompatibility of a new HDPE-based spherical porous orbital implants in rabbits. Methods. MEDPOR (Porex Surgical, Inc., Fairburn, GA, USA), OCULFIT I, and OCULFIT II (AJL Ophthalmic S.A., Vitoria, Spain) implants were implanted in eviscerated rabbis. Animals were randomly divided into 6 groups (n = 4 each) according to the 3 implant materials tested and 2 follow-up times of 90 or 180 days. Signs of regional pain and presence of eyelid swelling, conjunctival hyperemia, and amount of exudate were semiquantitatively evaluated. After animals sacrifice, the implants and surrounding ocular tissues were processed for histological staining and polarized light evaluation. Statistical study was performed by ANOVA and Kaplan-Meier analysis. Results. No statistically significant differences in regional pain, eyelid swelling, or conjunctival hyperemia were shown between implants and/or time points evaluated. However, amount of exudate differed, with OCULFIT I causing the smallest amount. No remarkable clinical complications were observed. Histological findings were similar in all three types of implants and agree with minor inflammatory response. Conclusions. OCULFIT ophthalmic tolerance and biocompatibility in rabbits were comparable to the clinically used MEDPOR. Clinical studies are needed to determine if OCULFIT is superior to the orbital implants commercially available.
PMCID: PMC4672132  PMID: 26689343
16.  The Effect of Cancer Therapies on Pediatric Anophthalmic Sockets 
Ophthalmology  2011;118(12):2480-2486.
To determine the impact of chemotherapy or external beam radiotherapy (EBRT) on pediatric anophthalmic sockets.
A retrospective, nonrandomized, interventional cohort study.
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.
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.
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).
In this unique pediatric population with cancer, chemotherapy and EBRT had an additive effect, significantly increasing the incidence of exposure and socket contracture.
PMCID: PMC3539308  PMID: 21856015
17.  Delayed onset porous polyethylene implant-related inflammation after orbital blowout fracture repair: four case reports 
BMC Ophthalmology  2016;16:94.
Porous polyethylene implants are commonly used in orbital blowout fracture repair because of purported biocompatibility, durability, and low frequency of complications. Delayed inflammation related to porous polyethylene sheet implants is very rare and no case series of this condition have been reported.
Case Presentation
This is a retrospective review of clinical presentations, radiographic findings, histopathological findings, treatments, and outcomes of patients who developed delayed complications in orbital blowout fracture repair using porous polyethylene sheets. Four male patients were included with a mean age of 49 years (range 35–69 years). Blowout fracture repair was complicated with implant-related inflammation 10 months, 2 years, 3 years, and 8 years after surgery. Chronic and subacute orbital inflammatory signs were noted in two patients and acute fulminant orbital inflammation was found in two patients. Three patients developed peri-implant abscesses and one patient had a soft tissue mass around the implant. All patients underwent implant removal and two of these patients with paranasal sinusitis had sinus surgery. Histopathological findings revealed chronic inflammatory changes with fibrosis, and one patient had foreign body granuloma with culture positive Staphylococcus aureus.
Delayed complications with porous polyethylene sheets used in orbital blowout fracture repair may occur many years following the initial surgery in immunocompetent patients. Low-grade or fulminant inflammation could complicate blowout fracture repair related with the implant.
PMCID: PMC4936306  PMID: 27387333
Delayed inflammation; Orbital fracture; Porous polyethylene
18.  A Case of Orbital Abscess following Porous Orbital Implant Infection 
We present a case of orbital abscess following porous orbital implant infection in a 73-year-old woman with rheumatoid arthritis.
Just one month after a seemingly uncomplicated enucleation and porous polyethylene (Medpor®) orbital implant surgery, implant exposure developed with profuse pus discharge. The patient was unresponsive to implant removal and MRI confirmed the presence of an orbital pus pocket. Despite extirpation of the four rectus muscles, inflammatory granulation debridement and abscess drainage, another new pus pocket developed.
After partial orbital exenteration, the wound finally healed well without any additional abscess formation.
A patient who has risk factors for delayed wound healing must be examined thoroughly and extreme care such as exenteration must be taken if there is persistent infection.
PMCID: PMC2908858  PMID: 17302210
Porous orbital implant infection; Orbital abscess; Partial orbital exenteration
19.  Medpor Craniotomy Gap Wedge Designed to Fill Small Bone Defects along Cranial Bone Flap 
Medpor porous polyethylene was used to reconstruct small bone defects (gaps and burr holes) along a craniotomy bone flap. The feasibility and cosmetic results were evaluated.
Medpor Craniotomy Gap Wedges, V and T, were designed. The V implant is a 10 cm-long wedge strip, the cross section of which is an isosceles triangle with a 4 mm-long base, making it suitable for gaps less than 4 mm after trimming. Meanwhile, the Medpor T wedge includes a 10 mm-wide thin plate on the top surface of the Medpor V Wedge, making it suitable for gaps wider than 4 mm and burr holes. Sixty-eight pterional craniotomies and 39 superciliary approaches were performed using the implants, and the operative results were evaluated with respect to the cosmetic results and pain or tenderness related to the cranial flap.
The small bone defects were eliminated with less than 10 minutes additional operative time. In a physical examination, there were no considerable cosmetic problems regarding to the cranial bone defects, such as a linear depression or dimple in the forehead, anterior temporal hollow, preauricular depression, and parietal burr hole defect. Plus, no patient suffered from any infectious complications.
The Medpor Craniotomy Gap Wedge is technically easy to work with for reconstructing small bone defects, such as the bone gaps and burr holes created by a craniotomy, and produces excellent cosmetic results.
PMCID: PMC2764015  PMID: 19844617
Cosmetic appearance; Craniotomy; Medpor; Operative technique
20.  Intrastromal Corneal Ring Implants for Corneal Thinning Disorders 
Executive Summary
The purpose of this project was to determine the role of corneal implants in the management of corneal thinning disease conditions. An evidence-based review was conducted to determine the safety, effectiveness and durability of corneal implants for the management of corneal thinning disorders. The evolving directions of research in this area were also reviewed.
Subject of the Evidence-Based Analysis
The primary treatment objectives for corneal implants are to normalize corneal surface topography, improve contact lens tolerability, and restore visual acuity in order to delay or defer the need for corneal transplant. Implant placement is a minimally invasive procedure that is purported to be safe and effective. The procedure is also claimed to be adjustable, reversible, and both eyes can be treated at the same time. Further, implants do not limit the performance of subsequent surgical approaches or interfere with corneal transplant. The evidence for these claims is the focus of this review.
The specific research questions for the evidence review were as follows:
Corneal Surface Topographic Effects:
Effects on corneal surface remodelling
Impact of these changes on subsequent interventions, particularly corneal transplantation (penetrating keratoplasty [PKP])
Visual Acuity
Refractive Outcomes
Visual Quality (Symptoms): such as contrast vision or decreased visual symptoms (halos, fluctuating vision)
Contact lens tolerance
Functional visual rehabilitation and quality of life
Patient satisfaction:
Disease Process:
Impact on corneal thinning process
Effect on delaying or deferring the need for corneal transplantation
Clinical Need: Target Population and Condition
Corneal ectasia (thinning) comprises a range of disorders involving either primary disease conditions such as keratoconus and pellucid marginal corneal degeneration or secondary iatrogenic conditions such as corneal thinning occurring after LASIK refractive surgery. The condition occurs when the normally round dome-shaped cornea progressively thins causing a cone-like bulge or forward protrusion in response to the normal pressure of the eye. Thinning occurs primarily in the stoma layers and is believed to be a breakdown in the collagen network. This bulging can lead to an irregular shape or astigmatism of the cornea and, because the anterior part of the cornea is largely responsible for the focusing of light on the retina, results in loss of visual acuity. This can make even simple daily tasks, such as driving, watching television or reading, difficult to perform.
Keratoconus (KC) is the most common form of corneal thinning disorder and is a noninflammatory chronic disease process. Although the specific causes of the biomechanical alterations that occur in KC are unknown, there is a growing body of evidence to suggest that genetic factors may play an important role. KC is a rare condition (<0.05% of the population) and is unique among chronic eye diseases as it has an early age of onset (median age of 25 years). Disease management for this condition follows a step-wise approach depending on disease severity. Contact lenses are the primary treatment of choice when there is irregular astigmatism associated with the disease. When patients can no longer tolerate contact lenses or when lenses no longer provide adequate vision, patients are referred for corneal transplant.
Keratoconus is one of the leading indications for corneal transplants and has been so for the last three decades. Yet, despite high graft survival rates of up to 20 years, there are reasons to defer receiving transplants for as long as possible. Patients with keratoconus are generally young and life-long term graft survival would be an important consideration. The surgery itself involves lengthy time off work and there are potential complications from long term steroid use following surgery, as well as the risk of developing secondary cataracts, glaucoma etc. After transplant, recurrent KC is possible with need for subsequent intervention. Residual refractive errors and astigmatism can remain challenging after transplantation and high refractive surgery rates and re-graft rates in KC patients have been reported. Visual rehabilitation or recovery of visual acuity after transplant may be slow and/or unsatisfactory to patients.
Description of Technology/Therapy
INTACS® (Addition Technology Inc. Sunnyvale, CA, formerly KeraVision, Inc.) are the only currently licensed corneal implants in Canada. The implants are micro-thin poly methyl methacrylate crescent shaped ring segments with a circumference arc length of 150 degrees, an external diameter of 8.10 mm, an inner diameter of 6.77 mm, and a range of different thicknesses. Implants act as passive spacers and, when placed in the cornea, cause local separation of the corneal lamellae resulting in a shortening of the arc length of the anterior corneal curvature and flattening the central cornea. Increasing segment thickness results in greater lamellar separation with increased flattening of the cornea correcting for myopia by decreasing the optical power of the eye. Corneal implants also improve corneal astigmatism but the mechanism of action for this is less well understood.
Treatment with corneal implants is considered for patients who are contact lens intolerant, having adequate corneal thickness particularly around the area of the implant incision site and without central corneal scarring. Those with central corneal scarring would not benefit from implants and those without an adequate corneal thickness, particularly in the region that the implants are being inserted, would be at increased risk for corneal perforation. Patients desiring to have visual rehabilitation that does not include glasses or contact lenses would not be candidates for corneal ring implants.
Placement of the implants is an outpatient procedure with topical anesthesia generally performed by either corneal specialists or refractive surgeons. It involves creating tunnels in the corneal stroma to secure the implants either by a diamond knife or laser calibrated to an approximate depth of 70% of the cornea. Variable approaches have been employed by surgeons in selecting ring segment size, number and position. Generally, two segments of equal thickness are placed superiorly and inferiorly to manage symmetrical patterns of corneal thinning whereas one segment may be placed to manage asymmetric thinning patterns.
Following implantation, the major safety concerns are for potential adverse events including corneal perforation, infection, corneal infiltrates, corneal neovascularization, ring migration and extrusion and corneal thinning. Technical results can be unsatisfactory for several reasons. Treatment may result in an over or under-correction of refraction and may induce astigmatism or asymmetry of the cornea.
Progression of the corneal cone with corneal opacities is also invariably an indication for progression to corneal transplant. Other reasons for treatment failure or patient dissatisfaction include foreign body sensation, unsatisfactory visual quality with symptoms such as double vision, fluctuating vision, poor night vision or visual side effects related to ring edge or induced or unresolved astigmatism.
Evidence-Based Analysis Methods
The literature search strategy employed keywords and subject headings to capture the concepts of 1) intrastromal corneal rings and 2) corneal diseases, with a focus on keratoconus, astigmatism, and corneal ectasia. The initial search was run on April 17, 2008, and a final search was run on March 6, 2009 in the following databases: Ovid MEDLINE (1996 to February Week 4 2009), OVID MEDLINE In-Process and Other Non-Indexed Citations, EMBASE (1980 to 2009 Week 10), OVID Cochrane Library, and the Centre for Reviews and Dissemination/International Agency for Health Technology Assessment. Parallel search strategies were developed for the remaining databases. Search results were limited to human and English-language published between January 2000 and April 17, 2008. The resulting citations were downloaded into Reference Manager, v.11 (ISI Researchsoft, Thomson Scientific, U.S.A), and duplicates were removed. The Web sites of several other health technology agencies were also reviewed including the Canadian Agency for Drugs and Technologies in Health (CADTH), ECRI, and the United Kingdom National Institute for Clinical Excellence (NICE). The bibliographies of relevant articles were scanned.
Inclusion Criteria
English language reports and human studies
Any corneal thinning disorder
Reports with corneal implants used alone or in conjunction with other interventions
Original reports with defined study methodology
Reports including standardized measurements on outcome events such as technical success, safety, effectiveness, durability, vision quality of life or patient satisfaction
Case reports or case series for complications and adverse events
Exclusion Criteria
Non-systematic reviews, letters, comments and editorials
Reports not involving outcome events such as safety, effectiveness, durability, vision quality or patient satisfaction following an intervention with corneal implants
Reports not involving corneal thinning disorders and an intervention with corneal implants
Summary of Findings
In the MAS evidence review on intrastromal corneal ring implants, 66 reports were identified on the use of implants for management of corneal thinning disorders. Reports varied according to their primary clinical indication, type of corneal implant, and whether or not secondary procedures were used in conjunction with the implants. Implants were reported to manage post LASIK thinning and/or uncorrected refractive error and were also reported as an adjunctive intervention both during and after corneal transplant to manage recurrent thinning and/or uncorrected refractive error.
Ten pre-post cohort longitudinal follow-up studies were identified examining the safety and effectiveness of INTAC corneal implants in patients with keratoconus. Five additional cohort studies were identified using the Ferrara implant for keratoconus management but because this corneal implant is not licensed in Canada these studies were not reviewed.
The cohorts implanted with INTACS involved 608 keratoconus patients (754 eyes) followed for 1, 2 or 3 years. Three of the reports involved ≥ 2 years of follow-up with the longest having 5-year follow-up data for a small number of patients. Four of the INTAC cohort studies involved 50 or more patients; the largest involved 255 patients. Inclusion criteria for the studies were consistent and included patients who were contact lens intolerant, had adequate corneal thickness, particularly around the area of the implant incision site, and without central corneal scarring. Disease severity, thinning pattern, and corneal cone protrusions all varied and generally required different treatment approaches involving defined segment sizes and locations.
A wide range of outcome measures were reported in the cohort studies. High levels of technical success or ability to place INTAC segments were reported. Technically related complications were often delayed and generally reported as segment migration attributable to early experience. Overall, complications were infrequently reported and largely involved minor reversible events without clinical sequelae.
The outcomes reported across studies involved statistically significant and clinically relevant improvements in corneal topography, refraction and visual acuity, for both uncorrected and best-corrected visual acuity. Patients’ vision was usually restored to within normal functioning levels and for those not achieving satisfactory correction, insertion of intraocular lenses was reported in case studies to result in additional gains in visual acuity. Vision loss (infrequently reported) was usually reversed by implant exchange or removal. The primary effects of INTACS on corneal surface remodelling were consistent with secondary improvements in refractive error and visual acuity. The improvements in visual acuity and refractive error noted at 6 months were maintained at 1 and 2-year follow-up
Improvements in visual acuity and refractive error following insertion of INTACS, however, were not noted for all patients. Although improvements were not found to vary across age groups there were differences across stages of disease. Several reports suggested that improvements in visual acuity and refractive outcomes may not be as large or predictable in more advanced stages of KC. Some studies have suggested that the effects of INTACs were much greater in flattening the corneal surface than in correcting astigmatism. However, these studies involved small numbers of high risk patients in advanced stages of KC and conclusions made from this group are limited.
INTACS were used for other indications other than primary KC. The results of implant insertion on corneal topography, refraction, and visual acuity in post-LASIK thinning cases were similar to those reported for KC. The evidence for this indication, however, only involved case reports and small case series. INTACS were also successfully used to treat recurrent KC after corneal transplant but this was based on only a single case report. Corneal implants were compared to corneal transplantation but these studies were not randomized and based on small numbers of selected patients.
The foremost limitation of the evidence base is the basic study design in the reports that involved longitudinal follow-up only for the treated group; there were no randomized trials. Follow-up in the trials (although at prescribed intervals) often had incomplete accounts of losses at follow-up and estimates of change were often not reported or based on group differences. Second, although standardized outcome measures were reported, contact lens tolerance (a key treatment objective) was infrequently specified. A third general limitation was the lack of reporting of patients’ satisfaction with their vision quality or functional vision. Outcome measures for vision quality and impact on patient quality of life were available but rarely reported and have been noted to be a limitation in ophthalmological literature in general. Fourth, the longitudinal cohort studies have not followed patients long enough to evaluate the impact of implants on the underlying disease process (follow-up beyond 3 years is limited). Additionally, only a few of these studies directly examined corneal thinning in follow-up. The overall quality of evidence determined using the GRADE hierarchy of evidence was moderate.
There is some evidence in these studies to support the claim that corneal implants do not interfere with, or increase the difficultly of, subsequent corneal transplant, at least for those performed shortly after INTAC placement. Although it’s uncertain for how long implants can delay the need for a corneal transplant, given that patients with KC are often young (in their twenties and thirties), delaying transplant for any number of years may still be a valuable consideration.
The clinical indications for corneal implants have evolved from management of myopia in normal eyes to the management of corneal thinning disorders such as KC and thinning occurring after refractive surgery. Despite the limited evidence base for corneal implants, which consists solely of longitudinal follow-up studies, they appear to be a valuable clinical tool for improving vision in patients with corneal thinning. For patients unable to achieve functional vision, corneal implants achieved statistically significant and clinically relevant improvements in corneal topography, refraction, and visual acuity, providing a useful alternative to corneal transplant. Implants may also have a rescue function, treating corneal thinning occurring after refractive surgery in normal eyes, or managing refractive errors following corneal transplant. The treatment offers several advantages in that it’s an outpatient based procedure, is associated with minimal risk, and has high technical success rates. Both eyes can be treated at once and the treatment is adjustable and reversible. The implants can be removed or exchanged to improve vision without limiting subsequent interventions, particularly corneal transplant.
Better reporting on vision quality, functional vision and patient satisfaction, however, would improve evaluation of the impact of these devices. Information on the durability of the implants’ treatment effects and their affects on underlying disease processes is limited. This information is becoming more important as alternative treatment strategies, such as collagen cross-linking aimed at strengthening the underlying corneal tissue, are emerging and which might prove to be more effective or increase the effectiveness of the implants, particularly in advances stages of corneal thinning.
Ontario Health System Considerations
At present there are approximately 70 ophthalmologists in Canada who’ve had training with corneal implants; 30 of these practice in Ontario. Industry currently sponsors the training, proctoring and support for the procedure. The cost of the implant device ranges from $950 to $1200 (CAD) and costs for instrumentation range from $20,000 to $30,000 (CAD) (a one time capital expenditure). There is no physician services fee code for corneal implants in Ontario but assuming that they are no higher than those for a corneal transplant, the estimated surgical costs would be $914.32(CAD) An estimated average cost per patient, based on device costs and surgical fees, for treatment is $1,964 (CAD) (range $1,814 to $2,114) per eye. There have also been no out of province treatment requests. In Ontario the treatment is currently being offered in private clinics and an increasing number of ophthalmologists are being certified in the technique by the manufacturer.
KC is a rare disease and not all of these patients would be eligible candidates for treatment with corneal implants. Based on published population rates of KC occurrence, it can be expected that there is a prevalent population of approximately 6,545 patients and an incident population of 240 newly diagnosed cases per year. Given this small number of potential cases, the use of corneal implants would not be expected to have much impact on the Ontario healthcare system. The potential impact on the provincial budget for managing the incident population, assuming the most conservative scenario (i.e., all are eligible and all receive bilateral implants) ranges from $923 thousand to $1.1 million (CAD). This estimate would vary based on a variety of criteria including eligibility, unilateral or bilateral interventions, re-interventions, capacity and uptake
Keratoconus, corneal implants, corneal topography, corneal transplant, visual acuity, refractive error
PMCID: PMC3385416  PMID: 23074513
21.  Autologous dermis graft at the time of evisceration or enucleation 
The British Journal of Ophthalmology  2007;91(11):1528-1531.
To present a new technique using autologous dermis graft at the time of enucleation or evisceration to replace the ocular surface area lost when the corneal scleral button is excised.
A retrospective, interventional, non‐comparative case series of patients who had an autologous dermis graft placed to assist in closure of Tenon's capsule and conjunctiva at the time of enucleation or evisceration. Medical records were reviewed and the following variables were recorded: age, sex, history of previous ocular surgery or radiation treatment, indication for surgery, type of surgery, laterality, type of orbital implant, size of implant, length of follow up, and complications.
Nine patients were identified (three male, six female) Five had enucleation with implant placement and four had evisceration with implant placement. Four individuals received unwrapped porous polyethylene spherical implants, three received silicone implants, and two received hydroxylapatite implants. Follow up ranged from 30 to 112 weeks (mean (SD), 61 (28) weeks). No operative or early complications were observed. One patient who had enucleation after two rounds of brachytherapy for uveal melanoma developed subsequent late exposure of the implant. There were no complications involving the graft donor site.
This small series shows that the use of a dermis graft is a safe and effective new technique to facilitate orbital rehabilitation. It is hypothesised that the extra surface area produced with a dermis graft preserves the fornices and allows a larger implant. It may also allow the implant to be placed more anteriorly which assists with both implant and prosthesis motility.
PMCID: PMC2095415  PMID: 17947269
enucleation; evisceration; dermis graft; orbital implant; anophthalmos
22.  Management of diplopia in patients with blowout fractures 
Indian Journal of Ophthalmology  2011;59(6):461-464.
To report the management outcomes of diplopia in patients with blowout fracture.
Materials and Methods:
Data for 39 patients with diplopia due to orbital blowout fracture were analyzed retrospectively. The inferior wall alone was involved in 22 (56.4%) patients, medial wall alone was involved in 14 (35.8%) patients, and the medial and inferior walls were involved in three (7.6%) patients. Each fracture was reconstructed with a Medpore® implant. Strabismus surgery or prism correction was performed in required patients for the management of persistent diplopia. Mean postoperative follow up was 6.5 months.
Twenty-three (58.9%) patients with diplopia underwent surgical repair of blowout fracture. Diplopia was eliminated in 17 (73.9%) patients following orbital wall surgery. Of the 23 patients, three (7.6%) patients required prism glasses and another three (7.6%) patients required strabismus surgery for persistent diplopia. In four (10.2%) patients, strabismus surgery was performed without fracture repair. Twelve patients (30.7%) with negative forced duction test results were followed up without surgery.
In our study, diplopia resolved in 30.7% of patients without surgery and 69.2% of patients with diplopia required surgical intervention. Primary gaze diplopia was eliminated in 73.9% of patients through orbital wall repair. The most frequently employed secondary surgery was adjustable inferior rectus recession and <17.8% of patients required additional strabismus surgery.
PMCID: PMC3214416  PMID: 22011490
Blowout; diplopia; prism; strabismus
23.  Long term follow up of bone derived hydroxyapatite orbital implants 
The British Journal of Ophthalmology  2002;86(11):1287-1292.
Aims: To document the long term experience of bone derived hydroxyapatite orbital implants and compare results using scleral wrapped implants with those not using sclera.
Methods: This retrospective case series reviewed the long term follow up of 118 patients with 120 eyes which had undergone enucleation and bone derived hydroxyapatite orbital implant insertion at Dunedin Hospital from 1977 until 2000. Patient details were obtained from theatre records, case note review, patient interview and examination, interview of patient relatives, and family general practitioner records.
Results: Of the 120 eyes 84 had bone derived hydroxyapatite orbital implants with sclera and 36 without sclera. Follow up was 0.5–25 years (mean 8.9 years). 25 (19.3%) suffered minor complications of limited exposure of the implant which resolved spontaneously, with implant drilling or wound resuture. Nine (7.5%) suffered major complications requiring explantation. Major complications were more likely in cases with major tissue disruption, ischaemia, or inflammation. There were significantly fewer complications in the group where a bone derived hydroxyapatite orbital implant was implanted without a scleral covering (p<0.05).
Conclusions: The placement of a bone derived hydroxyapatite orbital implant in the socket was associated with a low rate of long term complications and good cosmesis in most cases. The omission of a scleral covering over the hydroxyapatite sphere had some advantages and may prove to be the procedure of choice.
PMCID: PMC1771380  PMID: 12386091
bone derived hydroxyapatite; enucleation; orbital implants
24.  Standard Enucleation with Aluminium Oxide Implant (Bioceramic) Covered with Patient's Sclera 
The Scientific World Journal  2012;2012:481584.
Purpose. We describe in our study a modified standard enucleation, using sclera harvested from the enucleated eye to cover the prosthesis in order to insert a large porous implant and to reduce postoperative complication rates in a phthisis globe. Methods. We perform initially a standard enucleation. The porous implant (Bioceramic) is then covered only partially by the patient's sclera. The implant is inserted in the posterior Tenon's space with the scleral covering looking at front. All patients were followed at least for twelve months (average followup 16 months). Results. We performed nineteen primary procedures (19 patients, 19 eyes, x M; x F) and secondary, to fill the orbital cavity in patients already operated by standard evisceration (7 patients, 7 eyes). There were no cases of implant extrusion. The orbital volume was well reintegrated. Conclusion. Our procedure was safe and effective. All patients had a good cosmetic result after final prosthetic fitting and we also achieved good prothesis mobility.
PMCID: PMC3361278  PMID: 22654614
25.  Management of Radiation-induced Severe Anophthalmic Socket Contracture in Patients with Uveal Melanoma 
High-dose radiotherapy can cause contracture of the anophthalmic socket, but the incidence of this complication in patients with enucleation for uveal melanoma has not previously been reported. We reviewed the surgical management and outcomes in terms of successful prosthesis wear in patients with severe contracture of the anophthalmic socket treated with high-dose radiotherapy for high-risk uveal melanoma and estimated the relative risk of this complication.
The medical records of all consecutive patients enrolled in a prospective uveal-melanoma tissue-banking protocol at our institution who underwent enucleation between January 2003 and December 2010 were reviewed. Patients who underwent adjuvant radiotherapy of the enucleated socket were further studied.
Of the 68 patients enrolled in the prospective tissue banking protocol, 12 had high-risk histologic features (e.g., extrascleral spread or vortex vein invasion) and were treated with 60 Gy of external-beam radiotherapy after enucleation. Five of these patients (41.7%) experienced severe socket contracture precluding prosthesis wear. The median time to onset of contracture following completion of radiotherapy was 20 months. Three patients underwent surgery, which entailed scar tissue release, oral mucous membrane grafting, and socket reconstruction; 2 patients declined surgery. All 3 patients who had surgery experienced significant improvement of socket contracture that enabled patients to wear a prosthesis again.
High-dose radiotherapy after enucleation in patients with uveal melanoma caused severe socket contracture and inability to wear a prosthesis in approximately 40% of patients. Surgical repair of the contracted socket using oral mucous membrane grafting can allow resumption of prosthesis wear.
PMCID: PMC3359825  PMID: 22581085

Results 1-25 (935633)