Primary banked scleral patch graft in the prevention of exposure of hydroxyapatite orbital implants

Scleral thinning causes, diagnosis, and management: A narrative review

INTRODUCTION

Sclera forms the outer fibrous coat of the eye and provides structural integrity for the housing of intraocular contents. Scleral thinning is a serious progressive condition which can lead to perforation and worsening visual functioning. This review aims to summarize the anatomical consideration and causes of scleral thinning, diagnosis, and the various surgical approaches available to treat scleral thinning.

MATERIALS AND METHODS

The narrative literature review was conducted by senior Ophthalmologists and researchers. PubMed, EMBASE, Web of Science, Scopus, and Google Scholar databases were searched for relevant literature from infinity till March 2022. Terms of the search referred to 'sclera' or 'scleral thinning' or 'scleral melting', and were combined with 'treatment', or 'management' or 'causes'. Publications were included in this manuscript if they offered information about the nature of these topics. Reference lists of relevant literature was searched. There were no limits on type of article to be included for this review.

RESULTS

Scleral thinning arises from diverse congenital, degenerative, immunological, infectious, post-surgical, and traumatic etiologies. It is diagnosed upon slit-lamp examination, indirect ophthalmoscopy, and optical coherence tomography. Conservative pharmacological treatment of scleral thinning may include anti-inflammatory drugs, steroid drops, immunosuppressors, monoclonal antibodies, and surgical treatments including tarsorrhaphy, scleral transplantation, amniotic membrane transplantation, donor corneal graft, conjunctival flaps, tenon's membrane flap, pericardial graft, dermis graft, cadaveric dura mater graft, and other autologous and biological grafts.

CONCLUSION

Scleral thinning treatments have developed dramatically in recent decades and the rise of alternative grafts for scleral transplantation procedures or use of conjunctival flaps have taken center stage in surgical management. This review adds a comprehensive summary of the scleral thinning with attention to the positive and negative features of new treatments alongside previous mainstay management strategies.

The Scleral Cap Technique for Porous and Nonporous Orbital Implants

PURPOSE

To describe the results and potential benefit of a banked homologous donor scleral cap over the anterior surface of polyglactin 910 mesh-wrapped porous and nonporous orbital implants during enucleation and secondary orbital implant surgery.

METHODS

This is a single center, retrospective, clinical case series of 83 patients who received a polyglactin 910 mesh (Vicryl knitted mesh, undyed, Ethicon, Sommerville, New Jersey, USA) wrapped bioceramic or polymethylmethacrylate orbital implant (sphere or mounded) following enucleation and secondary orbital implant surgery by one surgeon over a 10-year period. A homologous donor scleral cap (approximately 1.5 × 1.5 cm diameter) was also placed over the anterior mesh-wrapped implant surface as an additional barrier. A minimum of 1-year follow up was required to be included in the study. The author analyzed patient demographics, type of surgery, implant type, implant size, follow-up duration, and presence or absence of implant exposure. The data from patients with greater than 1-year follow up are detailed in this report.

RESULTS

The author identified 100 patients in his case files that had a scleral cap put in place over their implant. Seventeen patients were either lost to follow up or did not have at least a 1-year follow up, leaving 83 patients (44 enucleations, 39 secondary implants) that were followed for 12 to 120 months (average 60.5 months). There were no cases of implant exposure identified in either group of patients during this time period.

CONCLUSIONS

Implant exposure can occur anytime post implant placement with a porous or nonporous orbital implant. This review suggests that a homologous donor scleral cap (approximately 1.5 × 1.5 cm diameter) over the polyglactin 910 mesh-wrapped implant surface may help prevent implant exposure. Patients with porous and nonporous orbital implants should be followed on a long-term basis as exposure can occur at anytime postsurgery, even several years later.

Unwrapped hydroxyapatite orbital implants: our experience in 347 cases

OBJECTIVES

To report the results of a large case series of enucleations with primary insertion of an unwrapped hydroxyapatite (HA) orbital implant.

METHODS

We retrospectively reviewed consecutive enucleations with primary orbital (HA) implant insertion performed at the Scottish Ocular Oncology Service, Glasgow between 1990 and 2014. The unwrapped hydroxyapatite orbital implant was placed in the posterior portion of the socket and recti muscles sutured end-to-end over the implant.

RESULTS

Out of 347 consecutive enucleations, the indication for enucleation was tumour-related pathology in 59.7% and painful blind eye in 40.3%. Majority (70%) received an implant of 22-mm diameter. At an average follow-up of 3.5 years, complications included post-enucleation socket syndrome (11.5%), chronic discharge (9.2%), chronic pain (4.3%), recurrent conjunctival infection (2.3%),conjunctival cysts (2%), contracted socket (1.4%), implant exposure (1.2%), haematoma (0.6%) and ill-fitting prosthesis (0.6%). Implant exposure (1.2%, n = 4) occurred at a mean of 4.5 months post surgery and was managed by temporalis fascia graft (n = 1), tarsoconjunctival flap (n = 1), implant removal (n = 1) and observation (n = 1). Overall, 9.8% of patients needed further surgery including lower lid tightening (4.3%), ptosis repair (2.3%), conjunctival cyst excision (1.2%), fornix reconstruction (1.2%), graft/flap for exposure (0.6%) and implant removal (0.3%).

CONCLUSIONS

A low rate of implant exposure indicates that absence of wrapping material around hydroxyapatite orbital implants does not compromise surgical outcomes and has the added benefit of reduced surgical time and avoidance of complications from wrapping materials. Posterior implant placement and end-to-end recti suturing contribute to the success of the procedure.

Effect of Melatonin on the Expression of VEGF-A and on the Degeneration of Follicle Reserve in Rat Ovary

Objective

To analyze the effects of melatonin on vascular endothelial growth factor A (VEGF-A) expression and follicle reserve in rat ovary.

Materials and Methods

A total of 45 female Wistar rats were used in the present study. Rats were divided into three groups: group 1 (control), group 2 (vehicle), and group 3 (melatonin). Rats in the melatonin group were treated with an intraperitoneal injection of melatonin at a dose of 50 mg/kg/day for 56 days. We investigated VEGF-A expression in rat ovary in all the groups using Western blot and reverse transcription-polymerase chain reaction. Histopathological parameters were evaluated using light microscopy.

Results

The number of atretic follicles was significantly lower in the melatonin treatment rats than in the control rats (p<0.05); however, the number of antral follicles was significantly higher in the former (p<0.05). Additionally, we observed a weak immunoblot stain in the melatonin group for VEGF-A protein. Interestingly, melatonin treatment induced a significant decrease in VEGF-A expression in the ovary of group 3 rats (p<0.05), whereas no such difference was observed between group 1 and group 2 rats (p>0.05).

Conclusion

The present study demonstrates that the protective effect of melatonin on the degeneration of follicles in rat ovary is reduced by decreasing the VEGF-A expression. These results suggest that melatonin is effective against follicular atresia and preserves antral follicles, thus, offering a therapeutic advantage in clinical use.

Anterior vestibule salvaging technique to limit silicone orbital implant extrusion following evisceration

Purpose: The anterior vestibule salvaging ('Birdcage') technique may limit orbital implant extrusion following evisceration. Methods: A 10-year retrospective chart review from 2005 to 2015 of individuals who underwent evisceration procedures utilizing the vestibule salvaging technique was performed. Results: A total of 96 patients (61 male; 35 female; average age 64 years; range 17-96 years) underwent evisceration with a technique avoiding anterior scleral relaxing incisions. Three (3.1%) patients had documented extrusion of the silicone implant. Time from evisceration to extrusion ranged from 26 to 372 days. Conclusions: Maintenance of the anterior scleral vestibule during evisceration may decrease extrusion rates after surgery compared with traditional evisceration techniques that utilize anterior relaxing incisions.

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

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

Exposure rate of unwrapped hydroxyapatite orbital implants in enucleation surgery

OBJECTIVE

To document the long-term exposure rate of unwrapped coralline hydroxyapatite (HA) orbital implants and explore possible risk factors.

DESIGN

This retrospective case series (May 2008-April 2013) reviewed the 234 patients with anophthalmia who underwent insertion of an unwrapped HA orbital implant by one of two different surgical closing techniques.

RESULTS

Of the 234 cases, 151 underwent a rectus end-to-end suturing closure technique and 83 underwent a rectus orthotopic suturing closure technique. The time of follow-up ranged from 25 months to 69 months (mean 41.9 months). Implant exposure developed in 11 cases. Three in the rectus end-to-end suturing closure group (2.0%) and eight in the rectus orthotopic suturing closure group (9.6%). In the rectus end-to-end suturing technique, a crosswise fixation of vascularised rectus muscle tissue is formed across the front of the implant; in this group the incidence of implant exposure was reduced (OR=8.11, p=0.013). Prior ocular surgery was found to be a factor increasing the incidence of HA exposure (OR=2.73, p=0.032).

CONCLUSIONS

The placement of an unwrapped HA orbital implant with rectus end-to-end suturing in enucleation surgery was associated with a low rate of exposure in most cases. The end-to-end suturing creates a joint-like structure over the HA sphere, protecting the Tenon's capsule and conjunctiva from its rough surface and reducing the risk of implant exposure. Prior ocular surgery may be another risk factor for HA exposure.

Use of extraocular muscle flaps in the correction of orbital implant exposure

Purposes

The study is to describe a new surgical technique for correcting large orbital implant exposure with extraocular muscle flaps and to propose a treatment algorithm for orbital implant exposure.

Methods

In a retrospective study, seven patients with orbital implant exposure were treated with extraocular muscle flaps. All data were collected from patients in Chang Gung Memorial Hospital, Taiwan during 2007–2012. All surgeries were performed by one surgeon (Y.J.T). Patient demographics, the original etiology, details of surgical procedures, implant types, and follow-up interval were recorded. Small exposure, defined as exposure area smaller than 3 mm in diameter, was treated conservatively first with topical lubricant and prophylactic antibiotics. Larger defects were managed surgically.

Results

Seven patients consisting of two males and five females were successfully treated for orbital implant exposure with extraocular muscle flaps. The average age was 36.4 (range, 3–55) years old. Five patients were referred from other hospitals. One eye was enucleated for retinoblastoma. The other six eyes were eviscerated, including one for endophthalmitis and five for trauma. Mean follow-up time of all seven patients was 19.5 (range, 2–60) months. No patient developed recurrence of exposure during follow-up. All patients were fitted with an acceptable prosthesis and had satisfactory cosmetic and functional results.

Conclusions

The most common complication of orbital implant is exposure, caused by breakdown of the covering layers, leading to extrusion. Several methods were reported to manage the exposed implants. We report our experience of treating implant exposure with extraocular muscle flaps to establish a well-vascularized environment that supplies both the wrapping material and the overlying ocular surface tissue. We believe it can work as a good strategy to manage or to prevent orbital implant exposure.

Standard enucleation with aluminium oxide implant (bioceramic) covered with patient's sclera

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.

Dermis-fat graft for treatment of exposed porous polyethylene implants in pediatric postenucleation retinoblastoma patients

PURPOSE

To demonstrate the use of the autogenous dermis-fat graft for the treatment of porous polyethylene implant exposure and volume augmentation in postenucleation retinoblastoma children.

DESIGN

Retrospective, interventional case series.

METHODS

Ten children who received a dermis-fat graft at Seoul National University Hospital between July 1, 2005 and January 31, 2010 were included in this study. The patients had undergone unilateral enucleation for retinoblastoma, and received a subconjunctival dermis-fat graft to repair implant exposure and simultaneously correct enophthalmos. The clinical characteristics of the patients, rate of graft survival, and complications were analyzed. The cosmetic outcome was assessed using a grading system.

RESULTS

All patients had enucleation using porous polyethylene implant as a primary orbital implant. The average time to exposure was 89.1 ± 22.4 months and the median size of defect was 2 × 3 mm. With a mean follow-up of 28 months, 9 of 10 patients showed well-survived graft without re-exposure. One patient who experienced a graft failure managed with implant rotation and a scleral graft. Seven patients showed significant improvement of enophthalmos.

CONCLUSIONS

Implantation of an autogenous dermis-fat graft is a procedure that can be effectively used to treat porous polyethylene implant exposure and simultaneously correct enophthalmos. Use of this procedure can be particularly advantageous for pediatric postenucleation patients.

The effect of autologous serum eye drops on the conjunctivalization over exposed porous polyethylene orbital implant (Medpor(®)) in the rabbit model

PURPOSE

To assess the efficacy of autologous serum eye drops (AS) in enhancing conjunctivalization over a scleral patch graft on exposed porous polyethylene orbital implant (Medpor(®)).

METHODS

Eighteen rabbits were underwent evisceration, implantation of Medpor(®) and homologous scleral patch graft. The conjunctival edge was sutured leaving 5 mm-diameter circular defect. In group A, 20% AS were applied 8 times a day and only balanced salt solution was applied in group B. Digital anterior segment photography was obtained 1, 3, 7, 10, 14, and 21 days after surgery and analyzed with Image Pro Plus(®) software.

RESULTS

In the early postoperative period, the average conjunctival growth rate (mm(2)/day) was faster in group A, but failed to show statistical significance (3.79 vs. 3.03, p = 0.26 in 1~3days, 2.39 vs. 1.80, p = 0.59 in 4- days, 0.03 vs. -0.02, p = 0.94 in 7-10 days, Mann-Whitney test). The complete healing rate was higher (67% vs. 56%, p = 0.5, Fisher's exact test) and the mean elapsed time for complete healing (days) was shorter in group A (17.3 vs. 18.2, p  = 0.83, Mann-Whitney test), but did not show a statistically significant difference.

CONCLUSION

In a rabbit model, 20% AS did not appear to facilitate the healing of small conjunctival defects of exposed porous orbital implant.

Scleral wrap increases the long-term complication risk of bone-derived hydroxyapatite orbital implants

BACKGROUND

This study was prompted by previous findings that suggested that scleral wrapping increased the rate of complications following insertion of bone-derived hydroxyapatite orbital implants and compared the long-term results of implants inserted with and without scleral wraps.

METHODS

This retrospective case series reviewed the long-term outcomes of 159 patients who had undergone enucleation with insertion of a bone-derived hydroxyapatite orbital implant at Dunedin Hospital between 1977 and 2006. Implants were inserted with and without scleral wraps in 85 and 74 cases, respectively. Follow up was 0.5-27.5 years (mean 8.2 years) for the whole series and 9.7 years for the sclera group and 6.7 years for the group without sclera. Patient details were obtained from theatre records, case note review, patient interview and examination, interview of patient relatives and family general practitioner records. The main outcome measures were the rates of minor or major complications and their treatments and outcomes.

RESULTS

Twenty-seven cases (17%) suffered minor complications of limited implant exposure that either healed spontaneously, with implant drilling or wound resuturing and 11 cases (7%) suffered major complications requiring explantation. Of 38 patients with postoperative complications, 31 (82%) had scleral wraps compared with 7 (18%) without sclera (P < 0.001; OR 5.14, 95% CI 2.00-14.78).

CONCLUSION

Bone-derived hydroxyapatite orbital implants inserted without scleral wrap were associated with better clinical outcomes and a lower rate of long-term complications. It is therefore recommended that these implants be inserted without a scleral wrap.

A histopathologic study of orbital implant vascularization

PURPOSE

To histopathologically assess the extent and pattern of vascularization of explanted porous polyethylene (PP) and hyrdoxyapatite (HA) orbital implants. To compare the vascularization in PP implants harvested after enucleation versus after evisceration.

METHODS

This is a comparative case series of six orbital implants explanted between 11 months and 5 years and 4 months post implantation. The implants were subjected to histopathological examination with various stains, after complete decalcification.

RESULTS

There were 2 post evisceration, 3 post enucleation and 1 secondary implant. The size of the implants varied from 18 to 23 mm diameter. The reason for explantation was exposure in all the 6 cases with additional infection in 2 cases. Histopathology revealed complete vascularization up to the core of the implant in all the cases. There was evidence of chronic inflammation within all the explanted specimens. Acute inflammation was present at the site of exposure in four of the implants. Three of these implants had additional evidence of necrosis. Two cases with clinically evident infection had Gram positive cocci within the implant. Foreign-body type giant-cells, melanophages and haemosiderin laden macrophages were also observed. Eviscerated specimens showed scleral remodelling and thickening.

CONCLUSION

All the implants were vascularized up to the core. There was histologic evidence of chronic inflammation in all the explanted implants possibly indicating the foreign nature of the implant material. The sclera did not impede vascularization of the implants in eviscerated specimens. We found no difference in the degree of vascularization of the implant in enucleated versus eviscerated implants.

Late exposure of the bioceramic orbital implant

PURPOSE

To investigate the long-term outcome of the Bioceramic orbital implant.

DESIGN

A retrospective, comparative, nonrandomized study.

METHODS

Data were collected from the patients receiving Bioceramic orbital implants at National Taiwan University Hospital between June 1, 2001 and November 1, 2005. The implant was wrapped with Vicryl mesh, adding anteriorly with a scleral patch graft following enucleation with primary or secondary implantation. The unwrapped implant was inserted into an eviscerated globe with posterior sclerotomy and cornea preserved. Primary or secondary placement of sleeve was performed in some patients.

RESULTS

A total of 112 cases were reviewed. Four patients were excluded attributable to insufficient follow-up. The other 108 patients had a mean follow-up period of 35.8 +/- 10.6 months (range, 24 to 70 months). Fifty patients (46.3%) received the pegging procedure. Eight of 108 (7.4%) cases of late exposure were identified on average 20.7 months after implantation. We identified no cases of implant exposure in 30 cases of enucleation and eight cases of secondary implant when the implant was wrapped in Vicryl mesh and an anterior scleral cap was used. All exposures developed in eviscerated patients (70 cases): two without pegging, three with primary placement, and three with secondary placement of the sleeve. The exposure rate was higher in patients with eviscerated globes, pegged implants, and prior ocular operations (P < .005).

CONCLUSIONS

Late exposures of Bioceramic implants were found after long-term follow-up, associated with evisceration, pegging, and prior ocular surgeries. The modified wrapping technique can prevent exposure following secondary implantation and enucleation.

Porous polyethylene (Medpor) orbital implants with primary acellular dermis patch grafts

PURPOSE

To evaluate the results of the porous polyethylene (Medpor) orbital implantation technique combined with the use of a primary patch graft of acellular dermis.

METHODS

The study design was a retrospective, non-comparative single surgeon case series of 27 patients. The Medpor orbital implant was placed with a primary anterior sub-Tenon's acellular dermis patch after evisceration (23/27), enucleation (2/27) or implant exchange/secondary implant procedure (2/27) over a period of 3 years. Risk factors for dehiscence/complications were defined as trauma, infection, inflammation, previous ocular surgery, radiotherapy, secondary orbital implantation, and removal of extruding implants. The primary outcome measure was the development of implant exposure. Other complications were also recorded, including postoperative conjunctival wound dehiscence.

RESULTS

Twenty-five patients (93%) had more than 2 risk factors. Mean follow-up time was 22 months (median 24 months, range 4-34 months). Three (11%) patients needed further intervention, which included pyogenic granuloma excision (1) and fornix formation (1). Conjunctival wound dehiscence followed by implant exposure occurred in 1 of 27 eyes (3.7%). The cosmetic appearance was satisfactory in 26/27 patients.

CONCLUSIONS

Our results with primary acellular dermis grafts when coupled with Medpor orbital implantation are encouraging.

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.

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.

Complications of primary placement of motility post in porous polyethylene implants during enucleation

PURPOSE

To evaluate the complications associated with the primary placement of a motility coupling post (MCP) in spherical porous polyethylene (PP) implants at the time of enucleation.

DESIGN

Retrospective, interventional case series.

METHODS

The records of all patients who had undergone primary enucleation and spherical PP implant with MCP insertion, and who were followed for at least six months were reviewed. The MCP was screwed to a wrapped implant to protrude 3 mm to 4 mm anteriorly. After placing the implant into the orbit, the extraocular muscles were sutured to the implant, and the Tenon capsule and conjunctiva were closed onto the MCP. When the MCP was not exposed spontaneously within two months after surgery, it was externalized with a conjunctival cut-down procedure.

RESULTS

The study included 52 patients (29 male, 23 female; age range, three to 76 years). The MCP became exposed spontaneously in 10 patients (19%). In the early postoperative period, we recorded nine complications in seven patients (13%), which might be related to primary MCP placement. These included prominent MCP decentration associated with implant motility restriction (6%), preseptal cellulitis (4%), and conjunctival prolapsus (8%). An ocular prosthesis was fit successfully onto the MCP in 51 patients. During the late period, 22 complications occurred in 15 patients (29%), including excessive discharge (15%), MCP decentration (4%), implant exposure (6%), implant infection (2%), pyogenic granuloma (8%), conjunctival overgrowth over the MCP (2%), conjunctival discoloration (4%), and lax eyelid syndrome (2%). Mean follow-up time was 34 months (range, six to 68 months).

CONCLUSIONS

Although MCP placement in the spherical PP implant during enucleation is a useful technique, it may be associated with complications such as MCP decentration, excessive discharge, exposure, and infection of the implant.

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.

Prevention of exposure of porous orbital implants following enucleation

PURPOSE

To investigate effectiveness of adding a scleral patch graft on a Vicryl mesh-wrapped porous orbital implant to prevent exposure following enucleation.

DESIGN

A retrospective, comparative, nonrandomized study.

METHODS

From October 1996 to February 2006, 74 consecutive patients (74 sockets) who received porous orbital implants primarily or secondarily after enucleation at National Taiwan University Hospital (72 cases) and at Far Eastern Memorial Hospital (2 cases) were collected. Patient demographics, ocular diagnosis, the surgical technique, prior ophthalmic surgery, type, covering, and size of the implant, follow-up periods, and complications associated with pegs and implants were recorded. Group 1 patients received a Vicryl mesh-wrapped implant without a scleral patch graft. Group 2 patients received anterior capping with a scleral patch on the Vicryl mesh-wrapped implant.

RESULTS

Of 74 identified cases, 12 were excluded for insufficient follow-up. The 62 remaining cases had more than a two-year follow-up. There were two implant exposures (12%, two of 17) in group 1. Retroauricular myoperiosteal graft and scleral patch were used to repair exposed implants successfully. No exposure was noted in group 2 (n = 45). A significant between-group difference in exposure rate was found (P = .02). Early conjunctival dehiscence followed by spontaneous healing occurred in three group 2 patients.

CONCLUSIONS

Scleral patch graft and Vicryl mesh can act as duplicate barriers between anterior surface of implants and overlying soft tissue. The modified wrapping technique prevents porous implants from exposure effectively.

Complications of Sclera-Covered Enucleation Implants

PURPOSE

To determine the incidence of complications associated with the use of donor human sclera to cover porous and nonporous enucleation implants.

METHODS

A retrospective case series of 207 patients receiving donor scleral-covered implants during a standardized enucleation procedure.

RESULTS

There was a single case of exposure among the 112 patients (0.9%) receiving nonporous implants. None of the 95 porous implants (0%) demonstrated primary exposure. Conditions leading to the removal of 3 of the 207 (1.4%) implants included primary exposure (n = 1), secondary exposure after peg insertion (n = 1), and postoperative pain (n = 1). Two patients (1%) required postoperative tarsorrhaphies to control chemosis. Conjunctival granulomas developed in 2 patients (1%). Asymptomatic implant rotation was observed in 31% (5/16) of patients receiving flattened porous implants. There were no cases of implant migration or prolonged inflammation related to the covering material.

CONCLUSIONS

Donor sclera covering of both porous and nonporous enucleation implants appears to be a successful surgical technique associated with few serious complications. The potential benefits of this technique must be balanced by the increased cost of the wrapping material and the rare but potential risk of transmitting infectious disease.

Bovine pericardium (Tutopatch) wrap for hydroxyapatite implants

PURPOSE

To evaluate bovine pericardium (Tutopatch) as a wrapping material for hydroxyapatite implants in patients undergoing enucleation for uveal melanoma.

METHOD

Prospective cohort study of patients who had enucleation for uveal melanoma between January 2003 and August 2003 were included in the study. Any patient with less than 3 months follow-up was excluded. Enucleation was performed under general anaesthesia followed by insertion of hydroxyapatite implants wrapped in bovine pericardium (Tutopatch). The recti muscles were sutured directly to the wrap. The tenon's capsule and conjunctiva were closed in two layers. A conformer was inserted at 1 week and artificial eye at 2-3 months. The patients were followed up regularly and were assessed for cosmetic result, exposure of implant, and the need for any further surgical procedures.

RESULTS

A total of 19 patients (seven male and 12 female) were included in the study. Median age at diagnosis was 63 years (range 38-80 years). Median follow-up was 26 months (range 22-30 months). No patient developed postoperative complications of wound dehiscence. The overall cosmetic result was excellent in all the patients. The rate of postoperative complications compared favourably with published data using other wrapping materials/implants.

CONCLUSION

Tutopatch is a safe wrapping material for hydroxyapatite orbital implants in patients undergoing enucleation for uveal melanoma.

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.

Cosmetic globe surgery in the horse

Effects of traumatic injury or inflammation on the equine eye can be catastrophic. These ocular conditions can frequently result in blindness or chronic pain. In addition to blindness and pain, permanent unsightly cosmetic defects can occur. This article addresses options available for improved cosmetic outcome in horses with ocular scars or requiring enucleation. Many of these options have been described in detail previously. New information has been added to the discussion of each option where pertinent.

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.

Safety of Unwrapped Spherical Orbital Implants

PURPOSE

To determine the exposure rate of unwrapped spherical orbital implants after enucleation surgery.

METHODS

Retrospective review of consecutive case series. All patients undergoing orbital implantation during enucleation surgery from October 1999 to September 2003 were included. Charts were reviewed for preoperative diagnoses, type and size of implant, use of a wrapping material, and complications.

RESULTS

Twenty-six consecutive patients underwent enucleation surgery without wrapping material. Nineteen patients received porous polyethylene, 5 patients received polymethylmethacrylate, and 2 received hydroxyapatite. Mean implant diameter was 21.03 mm. Mean follow-up was 17.1 months (range, 2 to 43 months). There were no complications of implant extrusion, exposure, infection, or migration.

CONCLUSIONS

The use of unwrapped spherical orbital implants may be associated with a low rate of early exposure. Careful choice of implant type may help reduce the risk of implant exposure.

Hydroxyapatite orbital implant exposure in children

PURPOSE

Hydroxyapatite orbital implants are buried implants that may be integrated into the overlying prosthesis after enucleation. We report problems encountered using these implants during a 14-year period in a pediatric population.

METHODS

Retrospective analysis of a pediatric population from 1987 through 2001.

RESULTS

Indications for enucleation (N = 19) included retinoblastoma (n =17), persistent hyperplastic primary vitreous (n =1), and painful blind eye (n =1). Conjunctival erosion (36.84%) and consequent implant exposure (15.70%) were the main problems identified in this study. There were no cases of orbital infection. Management included resuturing and scleral patching.

CONCLUSION

Conjunctival erosion of hydroxyapatite implants contributed to significant morbidity in 19 children who underwent enucleation and hydroxyapatite orbital implant.

Enucleation versus evisceration

Removal of the eye may be necessary after severe ocular trauma, to control pain in a blind eye, to treat some intraocular malignancies, in endophthalmitis unresponsive to medical therapy, and for cosmetic improvement of a disfigured eye. The choice of procedure to accomplish this is best made by an informed patient. Enucleation and evisceration can each achieve the desired goals, but several factors must be considered in choosing the most appropriate procedure.