|Year : 2017 | Volume
| Issue : 2 | Page : 87-90
Orbital implant exposure following enucleation or evisceration
Huda Abdullah Al-Farsi1, Buthaina Issa Sabt2, Abdullah Said Al-Mujaini2
1 Department of Ophthalmology, Al Nahdha Hospital, Muscat, Oman
2 Department of Ophthalmology, Sultan Qaboos University, Muscat, Oman
|Date of Web Publication||29-Jun-2017|
Huda Abdullah Al-Farsi
Al Nahdha Hospital, Ruwi, Muscat
Source of Support: None, Conflict of Interest: None
| Abstract|| |
PURPOSE: To study the exposure rate of orbital implant postenucleation or evisceration procedures in two tertiary hospitals in Oman.
DESIGN: A retrospective, descriptive, cross-section study.
MATERIALS AND METHODS: Patients' records were reviewed for patients' demographics, surgical indications, implant types, follow-up and any reported complications after surgeries. Patients with a minimum of 1 year follow-up period were selected. All patients who underwent enucleation or evisceration with primary orbital implant were included in the study. Patients who underwent secondary orbital implant were excluded from the study.
RESULTS: A total of 37 patients (age between 4 and 88-year-old, median age is 54-year-old) underwent enucleation or evisceration during 2008–2014. The most common indications for the surgical intervention were painful blind eye (35%), followed by trauma (16%), and perforated corneal ulcer (16%). Out of 37 patients, hydroxyapatite implant was implanted in 17 patients (46%), a glass or acrylic implant was implanted in 17 patients (46%), bioceramic implant was implanted in two patients (5%), and Molteno prosthesis was implanted in one patient (3%). There was no case of orbital implant exposure in any patients in this study.
CONCLUSIONS: No orbital implant exposure was recorded in this study. The surgical technique, end to end rectus muscles suturing, used for enucleation/evisceration was the main reason for reduced implant exposure. In addition, the preexisting ocular pathology did not affect the outcome of the study.
Keywords: Enucleation/evisceration procedures, glass/acrylic implant, hydroxyapatite implant, orbital implant exposure
|How to cite this article:|
Al-Farsi HA, Sabt BI, Al-Mujaini AS. Orbital implant exposure following enucleation or evisceration. Oman J Ophthalmol 2017;10:87-90
| Introduction|| |
Enucleation which involves the removal of diseased globe with part of the optic nerve may be performed for patients with severe eye trauma, panophthalmitis, painful blind eye, and patients with congenital anomalies, for example, microphthalmia. While evisceration which involves the removal of the contents of the globe, leaving the sclera, extraocular muscles, and optic nerve intact is generally considered for patients with endophthalmitis or perforated corneal ulcer.
The orbital implant, used after enucleation and evisceration surgeries, has several unique advantages. These advantages are to replace lost orbital volume, to maintain the structure of the orbit, and to aid motility to the overlying ocular prosthesis.
There are two main categories of implants grouped per the material from which they are manufactured inert material (glass, silicone, methyl methacrylate) and bio-integrated material (hydroxyapatite and porous polyethylene).
The inert implant characterized by providing comfort, cost-effectiveness, and lower rate of extrusion. Its disadvantages are decreased motility and risk of implant migration. On the other hand, bio-integrated implant provides excellent motility, but has a higher rate of postoperative complications, such as inflammation and exposure.
A recent study has calculated a 7.1% exposure rate for all porous implants placed after enucleation from 58 previously published studies. Another study showed that the exposure rate of hydroxyapatite orbital implants was 3.9%–2.1%. Other recorded complications included conjunctival dehiscence without exposure 3.5%, major discharge 4.7%, conjunctival cyst 0.2%, and severe conjunctival swelling in 0.2%.
Studies showed that the type of surgery (enucleation or evisceration), surgical technique, implant size, use of wrapping materials, and comorbidities associated with the reason for eye removal are some of the variables potentially influencing exposure rate.,,,
This study was conducted to study the incidence of orbital implant exposure in our population as no similar study conducted previously in our region and hence to improve the surgical outcome by improving the surgical technique used in such operations.
| Materials and Methods|| |
The study is a retrospective cross-section descriptive study, carried out in two tertiary hospitals in Oman. Patients who underwent enucleation or evisceration with primary orbital implants were included in the study. All data were collected from the electronic patients' records. The patients who were included in the study were the ones operated from January 2008 to December 2014 with a minimum follow-up period of 1 year. The data collected include patient demographics, surgical indications, surgical techniques, implant types, follow-up, and any reported implant exposure postoperation. The patient that included in the study was operated by two surgeons using the same surgical technique. All patients provided fully informed consent for surgery.
Enucleation/evisceration with primary orbital implants was performed in 37 patients during the specific period. Out of these, two patients had bioceramic orbital implant; one patient had Molteno prosthesis. The rest of the patients were implanted with either hydroxyapatite implant (17 patients) or glass/acrylic implant (17 patients). Twenty-six patients (70%) underwent evisceration [Figure 1] and 11 patients (30%) underwent enucleation [Figure 2]. The surgeries were performed by two oculoplasty surgeons, one in each hospital, but with similar surgical techniques. In evisceration, the implant was inserted into the sclera after creating several relaxing incisions in its wall to expand it more to accommodate a large implant. The scleral opening was closed with interrupted 5-0 Vicryl sutures. Tenon's capsule was then closed with interrupted 5-0 Vicryl sutures and the conjunctiva with a running 5-0 Vicryl suture. In enucleation, once the implant placed in the orbit, the surgeons sutured the horizontal and vertical rectus muscles together over the front of the implant. In all cases, Tenon's capsule closure over the implant was performed with interrupted 5-0 Vicryl sutures, and conjunctiva was closed with also 5-0 Vicryl. All implants were unwrapped. In most cases, either 20- or 22-mm implant was placed for adults or an 18- or 20 mm implant in children. Postoperation, patients were discharged on 4th generation ocular quinolones for 2–3 weeks. Regular follow ups after the operation were given to the patients in 2 weeks, 1, 3 and 6 months. The rest of follow ups ranged from 1year up to 5 years.
| Results|| |
A data of 39 patients were collected. Two patients were excluded as they underwent secondary orbital implants. The remaining 37 patients were included in the study. Eighteen of our patients (49%) were females, 19 (51%) were males [Figure 3]. The age group ranged between 4 and 88 years. Two of the patients were children at the ages of 4 and 6 years. The mean age was 47 years. The indications for the surgical intervention were painful blind eye (35%), followed by trauma (16%), and perforated corneal ulcer (16%). Other indications were endophthalmitis (14%), phthisis bulbi (8%), and congenital disfigured globe (5%) [Table 1]. There was no reported incidence of an implant exposure in any of these patients during the entire follow-up.
| Discussion|| |
Many studies have examined the exposure rate of different implant materials, wrapping methods, and surgical techniques. The type of surgery (enucleation or evisceration), surgical technique, use of wrapping material, implant size, and comorbidities associated with the reason for eye removal are some of the variables potentially influencing exposure rate making a direct comparison between methods and outcomes difficult., None of our patients had any reported incident of implant exposure. This can be explained by small sample size and the use of the similar surgical technique by both surgeons.
The surgical techniques used to secure the orbital implant in place play a critical role in reducing the risk of exposure. The techniques used to suture the rectus muscles can either increase or decrease the risk of implant exposure. Ye et al. have recently studied the exposure rate of unwrapped hydroxyapatite orbital implants in enucleation surgery in relation to the surgical technique used. The study included 234 cases, 151 underwent a rectus end-to-end suturing closure technique and 83 underwent a rectus orthoptic suturing closure technique with a follow-up period ranged from 25 to 69 months. Implant exposure developed in 11 cases. Three in the rectus end-to-end suturing closure group (2.0%), and eight in the rectus orthoptic suturing closure group (9.6%). In end-to-end suturing closure, the rectus muscles were drawn over the anterior surface of the implant and sutured end to end forming a joint-like structure crossing over the anterior part of the implant and acting as an interface between the implant and two layers of tissue, thus avoiding the risk of immune reaction and inflammation. All patients included in our study had rectus end-to-end suturing closure technique.
A major study carried out in Severance Hospital in Seoul in Korea, studied the exposure rate of hydroxyapatite orbital implants in 802 cases during 15 years. They found a 4% exposure rate and they conclude that exposures associated with hydroxyapatite implants decreased with the improvement of surgical technique over time. None of our hydroxyapatite implants had any exposure; however, the sample size in our study is much smaller than the Korean study.
To reduce or prevent the exposure of the porous orbital implants following enucleation procedure, improving the wrapping techniques can effectively help in achieving the aim. A study conducted in Taiwan found that scleral patch graft and Vicryl mesh can act as duplicate barriers between anterior surface of implants and overlying soft tissue. The exposure rate was 12% (2 out of 17 patients) in Group 1 who received a Vicryl mesh wrapped implant without scleral patch, and no exposure in Group 2 (45 patients), who received anterior capping with a scleral patch on the Vicryl mesh wrapped implant. No wrapping material around the implant was used in our study patients.
As we mentioned earlier, the incidence of orbital implant exposure is also influenced by previous ocular diseases, prior ophthalmic surgeries, implant size, and secondary implantation. A study was performed at Wilmer Eye Institute in the USA which showed 3.3% exposure rate in patients underwent enucleation with primary porous polyethylene implants (4 patients had implant exposure out of a total of 120 patients included in the study). Half of the exposure occurred in children enucleated for retinoblastoma undergoing perioperative chemotherapy, consistent with impairment of wound healing from chemotherapy.
Another study was done in The Children's Hospital in Dublin, Ireland about hydroxyapatite orbital implant exposure in children. Conjunctival erosion (36.84%) and consequent implant exposure (15.70%) were the main problems identified in this study. Management included resuturing and scleral patching. In this study, the two children had different types of orbital implants; one child had hydroxyapatite implant, and the other child had glass/acrylic implant and no complications reported for them so far.
A recent meta-analysis of case series studies was published, studying porous, and nonporous orbital implants for treating the anophthalmic socket. The study found that there is statistically significant difference between hydroxyapatite implant and bioceramic implant on implant exposure rate (0.054 vs. 0.12). They were unable to perform meta-analysis for silicon and poly (methyl methacrylate) implants as there were only two included case series with few number of patients for each procedure.
| Conclusion|| |
No orbital implant exposure was recorded in this study. The surgical technique, end to end rectus muscles suturing, used for enucleation/ evisceration was the main reason for reduced implant exposure. In addition, the pre existing ocular pathology did not affect the outcome of the study.
As exposure is a universal problem after orbital implant placement in the anophthalmic socket, patients should be examined yearly. The prosthetic eye should be cleaned and maintained properly. Meticulous surgical techniques should be employed.
The limitations of our study include: types of orbital implants used were not comparable (hydroxyapatite implants have higher risk of exposure in comparison to glass/acrylic implants) and size of the implant used was not recorded for all (the larger the implant size, the higher the risk of exposure).
The implants used in our patients were mainly hydroxyapatite and glass/acrylic, only two patients had bioceramic implants. There is a need for high-quality primary studies with longer follow-up and larger sample size comparing porous and nonporous implants in the treatment of anophthalmic socket.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
| References|| |
Holds JB, Chnag WJ, Durairai VD, Foster JA, Gausas RE, Harrison AR. Basic and Clinical Science Course: Orbital, Eyelids, and Lacrimal System. San Francisco: American Academy of Ophthalmology, the Eye M.D. Association; 2014-2015. p. 121-2.
Mahoney NR, Grant MP, Ilif NT, Merbs SL. Exposure rate of smooth surface tunnel porous polyethylene implants after enucleation. Am Soc Ophthalmic Plast Reconstr Surg 2014;30:492-8.
Yoon JS, Lew H, Kim SJ, Lee SY. Exposure rate of hydroxyapatite orbital implants. Am Acad Ophthalmol 2008;115:566-72.
Custer PL, Kennedy RH, Woog JJ, Kaltreider SA, Meyer DR. Orbital implants in enucleation surgery: A report by the American Academy of Ophthalmology. Ophthalmology 2003;110:2054-61.
Ye J, Gao Q, He JJ, Gao T, Ning QY, Xie JJ. Exposure rate of unwrapped hydroxyapatite orbital implants in enucleation surgery. Br J Ophthalmol 2016;100:860-5.
Wang JK, Liao SL, Lai PC, Lin LL. Prevention of exposure of porous orbital implants following enucleation. Am J Ophthalmol 2007;143:61-7.
Nolan LM, O'keefe M, Lanigan B. Hydroxyapatite orbital implant exposure in children. J AAPOS 2003;7:345-8.
Schellini SI, Jorge EL, Sousa RO, Burroughs JO, El-Dib RE. Porous and nonporous orbital implants for treating anophthalmic socket: A meta-analysis of case series studies. Int J Orbital Disord Oculoplastic Lacrimal Surg 2016;35:78-86.
[Figure 1], [Figure 2], [Figure 3]