|Year : 2020 | Volume
| Issue : 1 | Page : 50-54
Fabrication of custom scleral prosthesis for retinoblastoma
B Leela1, BK SriAshwini2, DB Nandeeshwar1
1 Department of Prosthodontics and Crown and Bridge, Bapuji Dental College and Hospital, Davanagere, Karnataka, India
2 Clove Dental Clinic, Bengaluru, Karnataka, India
|Date of Submission||11-Jan-2019|
|Date of Decision||25-Jan-2019|
|Date of Acceptance||04-Apr-2020|
|Date of Web Publication||16-Jul-2020|
Dr. B Leela
Department of Prosthodontics and Crown and Bridge, Bapuji Dental College and Hospital, Davanagere - 577 004, Karnataka
Source of Support: None, Conflict of Interest: None
Cancer is always a frightening diagnosis, and when it affects children, the situation is over-whelming. Eye cancer in children, though rare, is the third-leading cancer of childhood. Retinoblastoma can be a particularly distressing form of cancer as it is potentially fatal and can result in loss of one or both eyes. Providing the patient with a cosmetically pleasing, custom scleral prosthesis is a palliative approach for the rehabilitation of a pediatric patient with retinoblastoma. Custom scleral prosthesis not only fulfills the esthetic and psychological demands but also stimulates bony orbital growth, thereby reaping long-term benefits of restoring facial symmetry and esthetics.
Keywords: Custom made, ocular prosthesis, retinoblastoma, scleral prosthesis
|How to cite this article:|
Leela B, SriAshwini B K, Nandeeshwar D B. Fabrication of custom scleral prosthesis for retinoblastoma. Int J Oral Health Sci 2020;10:50-4
| Introduction|| |
Retinoblastoma is a highly malignant tumor of the eye that grows relentlessly and almost always has a fatal outcome, if untreated. Most tumors occur before the age of 2 years and are diagnosed before the age of 5 years. It accounts for approximately 2.5%–4% of all cancers diagnosed in children younger than 15 years. It has an incidence varying from 1 in 3300 to 1 in 20,000 live births. Approximately 40% of all retinoblastomas are bilateral and 60% are unilateral. Retinoblastoma can be hereditary (passed down in families) or nonhereditary.
- Forty percent of retinoblastoma patients have a genetic defect that leads to multiple tumors in one eye or both eyes. This is known as hereditary or germ-line retinoblastoma. These patients are typically diagnosed before 1 year of age
- Sixty percent of patients have the nonhereditary form of retinoblastoma. Each of these patients develops a tumor in only one eye. Nonhereditary patients are diagnosed on average around 2 years of age.
The modalities currently used to treat intraretinoblastoma include enucleation, laser photocoagulation, laser hyperthermia, cryotherapy, radioactive plaque brachytherapy, external-beam radiotherapy, and systemic chemotherapy. The approach to the treatment depends on the size and extent of tumors, the sites of involvement, and the patient's systemic involvement. Usually, several different modalities are necessary. Several studies have shown that the most common cause for enucleation in the pediatric population is retinoblastoma.
The loss of an eye can lead to significant functional and psychosocial impacts affecting sociometric stability. The loss of an eye due to congenital malformation, tumor treatment, or trauma can lead to serious functional, physical as well as psychological effects. The associated psychological effect of these defects on the patient requires immediate management and rehabilitation intervention by a team of specialists.
The associated psychological effect of these defects on the patient requires immediate management and rehabilitation intervention by a team of specialists. The combined efforts of the ophthalmologist, the plastic surgeon, psychologist, and the maxillofacial prosthodontist are essential to restore the patient's quality of life.
With the advancement in ophthalmic surgery and scleral prosthetics, the anopthalmic patient can be rehabilitated very effectively. Patient satisfaction with a scleral prosthesis is relatively high. In general, a conformer is advised during the initial 6 weeks; however, early insertion of the scleral prosthesis has been found to improve the quality of life. A custom scleral prosthesis is individually constructed and characterized to match the patient's natural eye, but it is a time-consuming process and difficult art to master. This case report presents a palliative approach to rehabilitate a 5-year-old boy with retinoblastoma, who has undergone enucleation of his left eye.
| Case Report|| |
A 5-year-old male patient reported to the Department of Prosthodontics, Bapuji Dental College and Hospital, Davangere, Karnataka, India. The patient's father complains of missing the left eye [Figure 1]. His father gave a history of infection to the left eye during his childhood. On examination, intrascleral tissue bed was healthy, eyeball was present, and with adequate depth between the upper and lower fornices for retention of the scleral prosthesis [Figure 2]. A written consent has been obtained from the parents of the patient for the purpose of publication.
A prefabricated stock eye shell was selected. Putty index of stock eye shell was made. Self-cure clear acrylic (DPI-RR cold-cure acrylic material, Dental products of India, Mumbai) was poured into the putty index to get the custom tray. Perforations were made in the custom tray. The custom tray was attached to a 5 ml disposable syringe using cyanoacrylate adhesive [Figure 3]. The custom tray was tried, and overextensions were corrected.
Tray adhesive was applied to the borders of the tray. Putty material (3M ESPE Express XT putty soft, Germany) was adapted to the borders of the tray and inserted into the socket. The patient was instructed to perform all the extreme border movements of the eye while putty sets. The tray was removed from the socket, and the syringe was filled with light-body PVS impression material (3M ESPE Imprint II Light body made in the USA). The tray was reinserted, and light body material was injected into the socket. The patient was instructed to perform eye movements while impression material sets. This allowed the impression material to flow over the underlying muscle bed and the anatomical details to be recorded accurately.
Light body material was added to the outer surface of the tray. The tray was reinserted into the socket, and the patient was asked to close the eye slowly. With both eyes closed, it was made sure that the outer contours of the eyelids mimic those of the adjacent normal eye. This functional molding resulted in the exact replication of the outer contours similar to that of the natural eye [Figure 4].
Lubricant was applied on impression surface; putty was adapted over the impression to create a positive replica of the eye socket. Softened wax was poured into the mold, and excess was removed [Figure 5]. Minimal alterations of the scleral wax pattern were done until satisfactory contours of the eyelids were achieved in open and closed position [Figure 6]. Horizontal and vertical lines were marked on the skin around both the eyes to create a grid to orient the iris. The patient was asked to gaze straight at an object kept four feet away. The iris disc position was matched with the natural eye with the use of iris button [Figure 7].
The finished pattern was invested in a crown flask using die stone. After the material was set, the flask was placed in a hot water bath for 10 min. The color of the sclera was selected using tooth color acrylic shade guide. A thin layer of tooth molding acrylic material (DPI Tooth molding powder, the product of India, Mumbai) was packed into the mold. The flask was kept for curing. After bench cooling, deflasking was done to retrieve scleral blank. Acrylic scleral blank was tried in patient's eye. Photographic iris disc technique was used to match the shade of iris disc [Figure 8].
Iris photo was attached to the scleral blank. Coating agent (monopoly) was prepared by mixing chemically activated methyl methacrylate monomer and clear methyl methacrylate polymer. The mixture was composed of one part powder to 10 parts liquid. A thin layer of monopoly was applied on the scleral blank. A thin layer of wax was applied on the scleral blank and tried in the patient's eye [Figure 9]. Flasking and dewaxing were done in conventional manner and packed with self-cure clear acrylic resin and cured [Figure 10].
After curing, the prosthesis was separated from the mold and finished and polished. The prosthesis was disinfected with betadine for 15 min and rinsed in sterile saline solution. The custom scleral prosthesis was then inserted [Figure 11]. The patient's father was instructed and trained on the aspect of insertion and easy removal of the scleral prosthesis.
| Discussion|| |
Enucleation during infancy or congenital anophthalmos or severe microphthalmos can lead to severely underdeveloped bony orbital growth, cosmetic deformity, and facial asymmetry. The placement of the prosthesis has been proven to play a definite role in stimulating orbital growth. In early childhood, orbital volume increases in a linear fashion in 18 months and 26 months following prosthesis placement in children.
The fundamental objective in restoring a congenital as well as acquired defect of eye with an scleral prosthesis is to enable the patient to cope better with the difficult process of rehabilitation after an enucleation or evisceration. A cosmetically acceptable prosthesis is that reproduces the color, form, and orientation of iris and allows the patient to return to accustomed lifestyle.
Numerous impression techniques have been described in the literature. They are broadly classified as direct impression/external impression, impression with stock scleral tray, stock scleral tray modification, impression with stock scleral tray, impression with stock scleral prosthesis, scleral prosthesis modification, and wax scleral blank technique.
The literature has suggested many techniques for the fabrication of scleral prosthesis. Stock eye prosthesis was advocated by Laney. They are available in different standard sizes, shapes, and colors and require no special skills or materials for fabrication. They are relatively inexpensive, and the entire process is also less time-consuming. However, in majority of cases of enucleation, custom scleral prosthesis is advantageous as there is improved adaptation to underlying tissues, increased mobility of the prosthesis, and excellent esthetics due to better match of the size and color of the iris and sclera.
| Conclusion|| |
The repercussions of retinoblastoma, its treatment, and its outcome are felt throughout the life of the patient and his/her family, and hence, providing the patient with a cosmetically pleasing scleral prosthesis is a palliative approach for the rehabilitation of a pediatric patient with retinoblastoma. The prosthodontist plays an important role by fabricating a scleral prosthesis and in turn rehabilitating the patient on emotional as well as the social front.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5], [Figure 6], [Figure 7], [Figure 8], [Figure 9], [Figure 10], [Figure 11]