Systemic chemotherapy and focal treatments have been increasingly used for globe salvage for retinoblastoma, even in advanced cases.1,2 However, enucleation remains the mainstay for advanced disease in many clinical scenarios, including persistent vitreous seeding, neovascular glaucoma, and disease resistant to chemotherapy and radiation.3,4 After enucleation, an orbital implant is placed in the anophthalmic socket to replace the orbital volume. The ideal implant provides good cosmesis, appropriate motility, and adequate orbital fill, which stimulates orbital growth in children.5,6
Porous orbital implants, including porous hydroxyapatite and porous polyethylene, have become the implants of choice in recent years in the United States.7 These implants should theoretically reduce migration, infection, and extrusion more than previously used alloplastic implants because of better fibrovascular ingrowth.8,9 Additionally, the extraocular muscles can be directly attached to the implant, which facilitates vascularization and provides a better approximation of the motility of the fellow eye.10
Implant exposure is the most frequent and important complication of porous orbital implants.11,12 This is especially the case in patients with retinoblastoma after enucleation who present with a higher number of exposures.13,14 It has been suggested that chemotherapy or radiotherapy may cause fibrotic change of the orbit leading to a higher rate of exposure.15,16 Many efforts have been made to reduce the exposure rate in this population, including choosing the most appropriate orbital implant and wrapping material, if any, and improved surgical techniques. Another proposed cause for exposures is friction between the conjunctiva covering the orbital implant and a poorly fitting prosthesis.15–19
This retrospective review was performed to analyze the effects of aggressive prosthesis refitting to minimize friction with the conjunctiva and underlying implant in patients with retinoblastoma who underwent enucleation and porous orbital implant insertion.
Patients and Methods
The medical records of all patients from the Bascom Palmer Eye Institute who underwent enucleation for advanced retinoblastoma and were observed by the same ocularist (SNG) were retrospectively reviewed. All surgeries were performed by one surgeon (TGM) between June 26, 1993, and November 30, 2007. Data are reported on 100 patients with at least 7 months of follow-up. The clinical variables evaluated included the age and sex of the patient and the type of implant inserted after enucleation. The use of preoperative or postoperative chemotherapy or external beam radiation was also considered. This study was approved by the Institutional Review Board of the University of Miami and conformed to the requirements of the United States Health Insurance Portability and Privacy Act.
The surgery was performed with general anesthesia. Initially, a 360° peritomy at the corneal limbus was performed and the rectus muscles were isolated on a muscle hook after the Tenon’s capsule was separated from the globe by blunt dissection. The isolated muscles were then tagged on a double-armed, locking 5-0 polyglactin 910 suture, cauterized, and disinserted from the globe. The superior and inferior oblique muscles were hooked, cauterized, and dissected from the globe and allowed to withdraw into the orbit. A snare was inserted as deep into the orbit as possible to obtain the maximum amount of optic nerve. The snare was then used to cut the optic nerve, and the globe was removed and immediately sent for pathology examination in all cases. Hemostasis was achieved through compression of the socket with a test tube and digital pressure.
An appropriately sized hydroxyapatite or porous polyethylene implant wrapped in donor sclera was then inserted as posteriorly as possible in the intraconal space. The sclera used had been screened for infectious disease, cancer, and other diseases. Wrapped hydroxyapatite implants were used until January 1, 2006, and wrapped porous polyethylene implants were used for all enucleations thereafter. The four rectus muscles were pulled through four previously made scleral windows and attached to the implant anterior to their anatomical position. The Tenon’s capsule was then closed using interrupted 5-0 polyglactin 910 suture, and the conjunctiva was closed using continuous 7-0 polyglactin 910 suture. A conformer and antibiotic ophthalmic ointment were inserted into the eye, and then a pressure patch was applied for 24 hours. The patients were then examined 6 to 8 weeks after surgery by the ocularist. None of the patients in this study underwent drilling or peg placement of their implants.
In addition to having the socket and prosthesis examined by the surgeon at each postoperative visit, the patients scheduled numerous visits with the ocularist. On initial examination after enucleation, a temporary prosthesis was provided to form the socket and shape the fornices. Measurements for the custom prosthesis were taken 2 weeks after insertion of the temporary prosthesis. After approximately 6 weeks, the patients returned for insertion of the custom prosthesis and were typically observed at 2- to 3-month intervals depending on the condition of the socket. When patients presented with anatomical changes to the orbit, forniceal shortening, conjunctival thinning, or a general poor fit, the prosthesis was adjusted. Adjustment involved vaulting, enlargement, and polishing as needed. When adjustments to the current prosthesis were not sufficient or two enlargements had already been made, the patients were refit for a new prosthesis.
To refit each patient, an alginate impression was created directly in the socket using a custom conformer for support. The polymethylmethacrylate prosthesis was trimmed according to the fit of the conformer and condition of the fornices. The width and depth of posterior vaulting was adjusted from the template dimensions based on the appearance of the implant and overlying conjunctiva. The iris, sclera, and pupil were hand painted and stained, and silk threading was used for the vasculature to mimic the appearance of the natural eye. All refits were performed in the office with the exception of impressions in patients younger than 2 years of age, which often required anesthesia. At each visit requiring an adjustment or refit, the ocularist evaluated the patient in four categories including prosthetic appearance, prosthetic functioning ability, implant condition, and condition of the fornices. The parameters for each category were quantified when possible, and the grading criteria for each category are listed in Table 1. Reference photographs were used as benchmarks for both prosthetic appearance (Fig. 1) and implant condition (Fig. 2).
Ocularist Guidelines for Grading of Prosthesis, Implant, and Fornices
(A) Example of a prosthesis receiving a score of 1 for prosthesis appearance. The left eye appears grossly abnormal because the prosthesis is causing entropion of the lower eyelid. (B) Example of a prosthesis receiving a score of 2 for prosthesis appearance. The prosthesis is causing protrusion of the right lower eyelid, demonstrating a significant difference from the natural eye. (C) Example of a prosthesis receiving a score of 3 for prosthesis appearance. The prosthesis in the right socket is moderately restricting eyelid closure, giving the appearance that the eye is more open in comparison to the natural eye. (D) Example of a prosthesis receiving a score of 4 for prosthesis appearance. The prosthesis is causing minor restriction of left eyelid closure, causing only a slight difference in appearance when compared with the natural eye. (E) Example of a prosthesis receiving a score of 5 for prosthesis appearance. The left eye has the prosthesis and is equal in appearance to the natural eye.
(A) Example of an implant receiving a score of 1 for implant condition. Note the significant conjunctival thinning with greater than 70% of the surface area lacking vascularity. (B) Example of an implant receiving a score of 2 for implant condition. Note the significant conjunctival thinning with approximately 40% of the conjunctival surface area showing devascularization. (C) Example of an implant receiving a score of 3 for implant condition. Moderate conjunctival thinning is noted with approximately 15% of the conjunctival surface area showing devascularization. (D) Example of an implant receiving a score of 4 for implant condition. Very mild conjunctival thinning without any areas of devascularization is noted. (E) Example of an implant receiving a score of 5 for implant condition. Note the thickness of the conjunctiva covering the implant.
The statistical software SPSS 16.0 (SPSS, Inc., Chicago, IL) was used in all analyses. The comparison between factor groups was performed using the two-sided Student t test for continuous variables. Pearson correlation coefficients were obtained for the correlations between prosthesis refit grades. A P value of .05 or less was considered statistically significant in our analyses.
Among the 100 patients who underwent enucleation for retinoblastoma, there were 48 males (48%) and 52 females (52%) with a mean age of 1.2 years (standard deviation = 1.1 years; range = 0 to 5 years) at enucleation. There were 43 right eyes (43%) and 57 left eyes (57%). A hydroxyapatite implant was used in 82 surgeries (82%) before January 1, 2006, at which point the implant was switched to porous polyethylene for the remaining 18 surgeries (18%). The insertion of the initial custom prosthesis was performed with a mean interval of 10 weeks (median = 7 weeks; range = 3 to 254 weeks) after enucleation. Ideally, placement of the prosthesis would have occurred within 4 to 8 weeks of enucleation, but two patients were lost to follow-up for a considerable period of time before returning for placement. The mean follow-up was 72 months (standard deviation = 49 months; range = 7 to 177 months), and no cases of exposure were noted.
There were 43 patients (43%) who underwent chemotherapy or external beam radiation therapy (EBRT) in addition to enucleation (Table 2). Thirty-two patients underwent chemotherapy only, 6 patients (6%) underwent EBRT only, and 5 patients (5%) received both chemotherapy and EBRT. Systemic chemotherapy was used in 37 patients (37%). The chemotherapy treatment consisted of carboplatin, vincristine, and etoposide in 17 patients (46%) and carboplatin, vincristine, etoposide, and cyclosporine in 20 patients (54%). Subconjunctival carboplatin was used in 1 patient (3%). Six patients underwent enucleation after EBRT, and 5 patients received EBRT after enucleation for treatment of retinoblastoma in the fellow eye.
Treatments Performed for Retinoblastoma in Addition to Enucleation
The mean frequency of visits to the ocularist was every 63 days (standard deviation = 39 days; range = 23 to 266 days). The mean frequency of prosthesis adjustment was every 154 days (standard deviation = 83 days; range = 53 to 532 days). The mean frequency of prosthesis refitting was every 263 days (standard deviation = 136 days; range = 83 to 800 days). The results showed that the frequency of visits with the ocularist and the frequency of prosthesis adjustments and refits were significantly correlated to the condition of the fornices, implant condition, and the prosthesis appearance and functioning ability (Table 3). Neither the age at enucleation nor the gender of the patient showed a significant correlation with any of the prosthesis evaluations. Additional treatment, including chemotherapy or EBRT, did not significantly affect the evaluation of the prosthesis (Table 4). Although the implant type did not statistically affect the prosthesis appearance or functioning ability or the condition of the conjunctival fornices, it did have a statistically significant effect on the implant condition.
Effects of Ocularist Management on Grading of the Prosthesis Implant and Fornices
Effects of Certain Variables on Grading of the Prosthesis, Implant, and Fornices
Porous orbital implants have become the most popular materials used in anophthalmic socket reconstruction because they allow fibrovascular ingrowth providing functional and cosmetic advantages.8,9,18 Despite this benefit, porous implants have related complications, the most significant of which is exposure.13,20 Although many factors have been discussed to reduce the rate of exposure, the role of the ocularist has not received much attention. With appropriate follow-up and management by the ocularist, most complications can be avoided.
Two mechanisms of exposure have been proposed in the literature. Wound breakdown is thought to be the underlying cause of exposures that are detected soon after surgery and may be caused by tension on the Tenon’s capsule or poor closure.13,17 Chronic conjunctival erosion due to friction between the prosthesis and the anterior surface of the implant is associated with late exposure.15–18
There are no conclusive data on what the most effective treatment modality is once implant exposure has occurred. Allowing time for the exposure to close on its own is potentially problematic because chronic exposure has been suggested to increase infection risk.17,21 Additionally, spontaneous healing has been rare, occurring in only 13% of reported cases.22 Although surgical intervention is required and eventually successful in most cases, it may reduce the cosmetic result due to re-operation.20 Therefore, the best management of implant exposure is prevention.
Improved surgical techniques are sufficient to significantly reduce wound breakdown. Choosing an appropriately sized implant is critical to adequately stimulate orbital growth without producing undue tension on the Tenon’s capsule and the conjunctiva.18,23 This is managed by considering both the age of the patient and the orbital size. Proper wound closure is another important preventative factor.19,22 We recommend using an ample amount of Tenon’s fascia to embed the implant deep in the orbit and closing the capsule in a double-layered fashion. The overlying conjunctiva can then be closed with a running 7-0 polyglactin 910 suture.
To minimize conjunctival erosion secondary to friction from the prosthesis, some have suggested the importance of an extra layer between the implant and the conjunctiva.24–26 Custer et al.22 reported both coralline hydroxyapatite and porous polyethylene implants wrapped in dura, sclera, or fascia to have appreciably lower incidences of exposure (1.2%, 2.7%, and 2.9%, respectively) than other wrapping materials (9.2%) and implantation without wrapping (14.7%). We used donor sclera to wrap all of the implants, which we believe contributed to the lack of exposure in this series.
As previously stated, few reports have discussed the value of the role of the ocularist.13,15 Iordanidou et al.13 discussed the occurrence of an implant exposure in a patient who had not been seen by an ophthalmologist or ocularist for a 2-year period, and De Potter et al.15 discussed the need for a highly vaulted prosthesis to decrease tissue necrosis on the anterior position of the sphere. We believe the function of the ocularist is underrated and extremely important in the management of conjunctival changes due to friction with the prosthesis. With frequent follow-up, the ocularist is able to notice minor changes in the condition of the conjunctiva and appropriately vault or refit the prosthesis before conjunctival erosion occurs. This series showed a significant improvement in the implant condition with increased frequency of ocularist visits and prosthesis adjustments and refits.
Previous reports demonstrate the rate of exposure in the pediatric population is higher than in the adult population.19,24 It is even higher in pediatric sockets that have undergone enucleation for retinoblastoma rather than for non-malignant diseases.13,14,16,17,23,27 A review of results from several clinical studies11,13,14,16,17,20,21,23–26,28–31 shows a combined 15% exposure rate (82 of 531 eyes) of orbital implants in patients with retinoblastoma (Table 5). This is considerably higher than the 6.5% rate of exposure (96 of 1,475) of porous implants after enucleation for all diagnoses in a review of published reports from 1991 to 2004.22
Review of Published Reports of Orbital Implant Exposure for Retinoblastoma After Enucleation
A few theories have been proposed to explain this disparity in exposure rate. Custer et al.22 suggested the high percentage of unwrapped porous polyethylene implants in patients with retinoblastoma is a significant factor in the elevated exposure rate. This reiterates the effect of friction from the prosthesis on the implant and encourages the use of implant wrapping and prosthesis refitting.
The most widely suggested cause of exposure is the difficulty of properly fitting a prosthesis in children.13,16,17,19,29 In our experience, having the ocularist attend the examinations under anesthesia alleviates this problem. Not only does it allow the ocularist the opportunity to create a mold for the prosthesis while the child is under anesthesia, it offers the added benefit of consultation with the surgeon about the condition of the implant and required adjustments to the prosthesis.
The use of radiation and chemotherapy is another possible basis for an enhanced rate of exposure in the retinoblastoma population.16,17,24 Radiation is thought to predispose the eye to socket contracture,23 and chemotherapy delays wound healing.4 However, there have been no studies to date that demonstrate a statistically significant increase in rate of exposure due to chemotherapy or radiation treatment. Both Lee et al.17 and Kim et al.18 show more exposures in patients who underwent chemotherapy, but this difference did not reach statistical significance. Although both treatments may theoretically increase the risk of exposure, our study suggests aggressive prosthesis refitting minimizes exposures even in this population.
In addition to reducing complications with the implant, continuous prosthesis management also encourages orbital growth and improves motility. Frequent examinations by the ocularist provide the opportunity to fit the prosthesis to the orbit as anatomical changes occur from growth. This not only maintains a good cosmetic effect, but it also promotes orbital growth.6 Regular follow-up also allows the ocularist to adjust the prosthesis to prevent forniceal shortening and eventual scarring. Larger fornices provide more space for the prosthesis to move along with the implant, giving the eye a more complete range of motion. Combining this technique with the use of porous orbital implants should maximize motility.
In this study, the porous polyethylene implant received higher ratings than the hydroxyapatite implant for implant condition, which seems to indicate a lower risk of exposure with the use of this implant. This may be explained by the shorter duration of follow-up in the patients who received the porous polyethylene implant.
Weaknesses to this review include its retrospective and nonrandomized nature. Additionally, this report did not have a control group, so we used the published literature as a historical control. To eliminate the confounding factor of evolving surgical techniques over time, we examined the literature for retinoblastoma that included surgeries from the same historical time period as ours, 1994 to 2008.
Continuous follow-up and frequent prosthesis refitting by the ocularist improves functional motility and cosmetic effect, stimulates orbital growth, and effectively prevents orbital implant exposure when added to the postoperative care.
- Schefler AC, Cicciarelli N, Feuer W, Toledano S, Murray TG. Macular retinoblastoma: evaluation of tumor control, local complications, and visual outcomes for eyes treated with chemotherapy and repetitive foveal laser ablation. Ophthalmology. 2007;114:162–169. doi:10.1016/j.ophtha.2006.06.042 [CrossRef]
- Rodriguez-Galindo C, Chantada GL, Haik BG, Wilson MW. Treatment of retinoblastoma: current status and future perspectives. Curr Treat Options Neurol. 2007;9:294–307. doi:10.1007/s11940-007-0015-4 [CrossRef]
- Abramson DH, Schefler AC. Update on retinoblastoma. Retina. 2004;24:828–848. doi:10.1097/00006982-200412000-00002 [CrossRef]
- Epstein JA, Shields CL, Shields JA. Trends in the management of retinoblastoma: evaluation of 1,196 consecutive eyes during 1974 to 2001. J Pediatr Ophthalmol Strabismus. 2003;40:196–203.
- Fountain TR, Goldberger L, Murphree Al. Orbital development after enucleation in early childhood. Ophthal Plast Reconstr Surg. 1999;15:32–36. doi:10.1097/00002341-199901000-00008 [CrossRef]
- Yago K, Furuta M. Orbital growth after unilateral enucleation in infancy without an orbital implant. Jpn J Ophthalmol. 2001;45:648–652. doi:10.1016/S0021-5155(01)00427-0 [CrossRef]
- Su GW, Yen MT. Current trends in managing the anophthalmic socket after primary enucleation and evisceration. Ophthal Plast Reconstr Surg. 2004;20:274–280. doi:10.1097/01.IOP.0000129528.16938.1E [CrossRef]
- Moshfeghi DM, Moshfeghi AA, Finger PT. Enucleation. Surv Ophthalmol. 2000;44:277–301. doi:10.1016/S0039-6257(99)00112-5 [CrossRef]
- Trichopoulos N, Augsburger JJ. Enucleation with unwrapped porous and nonporous orbital implants: a 15-year experience. Ophthal Plast Reconstr Surg. 2005;21:331–336. doi:10.1097/01.iop.0000175034.88019.a5 [CrossRef]
- Perry AC. Integrated orbital implants. Adv Ophthalmic Plast Reconstr Surg. 1990;8:75–81.
- Yoon JS, Lew H, Kim SJ, Lee SY. Exposure rate of hydroxyapatite orbital implants a 15-year experience of 802 cases. Ophthalmology. 2008;115:566–572.e2. doi:10.1016/j.ophtha.2007.06.014 [CrossRef]
- Buettner H, Bartley GB. Tissue breakdown and exposure associated with orbital hydroxyapatite implants. Am J Ophthalmol. 1992;113:669–673.
- Iordanidou V, De Potter P. Porous polyethylene orbital implant in the pediatric population. Am J Ophthalmol. 2004;138:425–429. doi:10.1016/j.ajo.2004.04.062 [CrossRef]
- Remulla HD, Rubin PA, Shore JW, et al. Complications of porous spherical orbital implants. Ophthalmology. 1995;102:586–593.
- De Potter P, Shields CL, Shields JA, Singh AD. Use of hydroxyapatite ocular implant in the pediatric population. Arch Ophthalmol. 1994;112:208–212.
- Karcioglu ZA, Mullaney PB, Millar LC. Extrusion of porous polyethylene orbital implant in recurrent retinoblastoma. Ophthal Plast Reconstr Surg. 1998;14:37–44. doi:10.1097/00002341-199801000-00009 [CrossRef]
- Lee V, Subak-Sharpe I, Hungerford JL, Davies NP, Logani S. Exposure of primary orbital implants in postenucleation retinoblastoma patients. Ophthalmology. 2000;107:940–945. doi:10.1016/S0161-6420(00)00016-6 [CrossRef]
- Kim NJ, Khwarg SI, Choung HK, Yu YS. Management of porous polyethylene implant exposure in patients with retinoblastoma following enucleation. Ophthalmic Surg Lasers Imaging. 2004;35:446–452.
- Shields CL, Shields JA, De Potter P, Singh AD. Lack of complications of the hydroxyapatite orbital implant in 250 consecutive cases. Trans Am Ophthalmol Soc. 1993;91:177–189.
- Heimann H, Bechrakis NE, Zepeda LC, Coupland SE, Hellmich M, Foerster MH. Exposure of orbital implants wrapped with polyester-urethane after enucleation for advanced retinoblastoma. Ophthal Plast Reconstr Surg. 2005;21:123–128. doi:10.1097/01.IOP.0000152495.25263.61 [CrossRef]
- Nolan LM, O’Keefe M, Lanigan B. Hydroxyapatite orbital implant exposure in children. J AAPOS. 2003;7:345–348. doi:10.1016/S1091-8531(03)00183-6 [CrossRef]
- Custer PL, Trinkaus KM. Porous implant exposure: incidence, management, and morbidity. Ophthal Plast Reconstr Surg. 2007;23:1–7. doi:10.1097/01.iop.0000249432.18688.ee [CrossRef]
- Christmas NJ, Van Quill K, Murray TG, et al. Evaluation of efficacy and complications: primary pediatric orbital implants after enucleation. Arch Ophthalmol. 2000;118:503–506.
- Li T, Shen J, Duffy MT. Exposure rates of wrapped and unwrapped orbital implants following enucleation. Ophthal Plast Reconstr Surg. 2001;17:431–435. doi:10.1097/00002341-200111000-00009 [CrossRef]
- Wang JK, Liao SL, Lin LL, Kao SC, Tseng HS. Porous orbital implants, wraps, and PEG placement in the pediatric population after enucleation. Am J Ophthalmol. 2007;144:109–116. doi:10.1016/j.ajo.2007.03.042 [CrossRef]
- Blaydon SM, Shepler TR, Neuhaus RW, White WL, Shore JW. The porous polyethylene (Medpor) spherical orbital implant: a retrospective study of 136 cases. Ophthal Plast Reconstr Surg. 2003;19:364–371. doi:10.1097/01.IOP.0000083643.36461.84 [CrossRef]
- Karesh JW, Dresner SC. High-density porous polyethylene (Medpor) as a successful anophthalmic socket implant. Ophthalmology. 1994;101:1688–1696.
- Shields CL, Shields JA, De Potter P, Singh AD. Problems with the hydroxyapatite orbital implant experience with 250 consecutive cases. Br J Ophthalmol. 1994;78:702–706. doi:10.1136/bjo.78.9.702 [CrossRef]
- Kim NJ, Choung HK, Khwarg SI, Yu YS. Free orbital fat graft to prevent porous polyethylene orbital implant exposure in patients with retinoblastoma. Ophthal Plast Reconstr Surg. 2005;21:253–258. doi:10.1097/01.iop.0000170406.09927.c4 [CrossRef]
- Shields CL, Uysal Y, Marr BP, et al. Experience with the polymer-coated hydroxyapatite implant after enucleation in 126 patients. Ophthalmology. 2007;114:367–373. doi:10.1016/j.ophtha.2006.08.030 [CrossRef]
- Marx DP, Vagefi MR, Bearden WH, Anderson RL, Yen MT. The quasi-integrated porous polyethylene implant in pediatric patients enucleated for retinoblastoma. Orbit. 2008;27:403–406. doi:10.1080/01676830802345042 [CrossRef]
Ocularist Guidelines for Grading of Prosthesis, Implant, and Fornices
|Prosthetic Appearancea||Functioning Ability||Implant Conditionb||Condition of Fornices|
|1||Poor appearance; gross difference from natural eye||Prosthesis falls out with no blink||Implant migrated and/or conjunctival thinning and > 70% of conjunctival surface area devascularized||Significant shortening and scarring of fornices|
|2||Significant difference from natural eye||Stable prosthesis; implant moves with extraocular muscle use but prosthesis does not||Implant centrally located; conjunctival thinning and between 30% and 70% of conjunctival surface area devascularized||Moderate forniceal shortening|
|3||Moderate difference from natural eye||Slight prosthesis movement||Implant centrally located; conjunctival thinning and < 30% of conjunctival surface area devascularized||Some forniceal shortening; prosthesis stable|
|4||Minor difference from natural eye||Eyelids blink freely; nearly full range of motion||Implant centrally located; conjunctival thinning with full vascularization||Slight shortening of fornices|
|5||Prosthesis equal to natural eye in appearance||Full prosthetic range of motion||Implant centrally located; no conjunctival thinning||Perfect fornices|
Treatments Performed for Retinoblastoma in Addition to Enucleation
|Treatment Used||No. of Patients|
|Chemotherapy or EBRT||43|
|Carboplatin, vincristine, etoposide||17|
|Carboplatin, vincristine, etoposide, and cyclosporin||20|
|EBRT before enucleation||6|
|EBRT after enucleation (RB in fellow eye)||5|
Effects of Ocularist Management on Grading of the Prosthesis Implant and Fornicesa
|Characteristic||Frequency of Prosthesis Visit||Frequency of Prosthesis Adjustment||Frequency of Prosthesis Refit||Age at Enucleation|
|Prosthesis appearance||r = −0.55; P < .001||r = −0.54; P < .001||r = −0.54; P < .001||r = −0.16; P = .12|
|Implant condition||r = −0.60; P < .001||r = −0.57; P < .001||r = −0.62; P < .001||r = −0.15; P = .14|
|Condition of fornices||r = −0.58; P < .001||r = −0.55; P < .001||r = −0.60; P < .001||r = −0.17; P = .10|
|Prosthesis function ability||r = −0.60; P < .001||r = −0.56; P < .001||r = −0.59; P < .001||r = −0.17; P = .09|
Effects of Certain Variables on Grading of the Prosthesis, Implant, and Fornicesa
|Factors||Prosthesis Appearance||Implant Condition||Condition of Fornices||Prosthesis Function Ability|
|Mean (SD)||P||Mean (SD)||P||Mean (SD)||P||Mean (SD)||P|
| Male||4.11 (0.65)||.45||3.80 (0.71)||.57||3.92 (0.75)||.88||3.81 (0.78)||.68|
| Female||4.21 (0.55)||3.89 (0.71)||3.94 (0.66)||3.87 (0.67)|
| Hydroxyapatite||4.15 (0.62)||.49||3.77 (0.72)||.024||3.89 (0.73)||.12||3.79 (0.76)||.07|
| Porous polyethylene||4.25 (0.45)||4.18 (0.57)||4.13 (0.52)||4.06 (0.51)|
|Chemotherapy or EBRT|
| With||4.09 (0.59)||.31||3.85 (0.68)||.93||3.88 (0.70)||.51||3.77 (0.73)||.42|
| Without||4.22 (0.60)||3.84 (0.74)||3.97 (0.71)||3.89 (0.72)|
Review of Published Reports of Orbital Implant Exposure for Retinoblastoma After Enucleation
|Studya||Implant Type||Wrapping Materials||No. of Eyes||No. of Exposures||Rate (%)||Time to Complication (Mo)|
|Shields et al.28||HA||DS||70||3||4.3||4.7|
|Remulla et al.14||PP||None||1||1||100||1.5|
|Karcioglu et al.16||PP||None||37||8||21.6||18.9|
|Christmas et al.23b||Multiple||DS or none||106||3||2.8||38.9|
|Lee et al.17||Multiple||Multiple||108||30||27.8||4.5|
|Li et al.24||PP||Multiple||6||1||16.6||12.5|
|Nolan et al.21c||HA||17||7||41.1||5.6|
|Blaydon et al.26||PP||DS||1||0||0|
|Iordanidou et al.13||PP||DS||21||0||0|
|Heimann et al.20||Multiple||Multiple||32||7||22||12.5|
|Kim et al.29d||PP||Orbital fat||38||0||0|
|Shields et al.30||PCHA||Multiple||34||3||8.8||4|
|Wang et al.25||Multiple||Multiple||34||6||17.6||4.3|
|Yoon et al.11||HA||Multiple||21||1||4.8||24|
|Marx et al.31||QIPP||None||10||1||10||15|