|Year : 2016 | Volume
| Issue : 2 | Page : 82-85
A novel technique of custom ocular prosthesis fabrication
Anish Varkey John, S Anilkumar, C Rajesh, Sandhya M Raghavan
Department of Prosthodontics, Government Dental College, Kottayam, Kerala, India
|Date of Web Publication||13-Oct-2016|
Anish Varkey John
Department of Prosthodontics, Government Dental College, Gandhinagar P. O., Kottayam - 686 008, Kerala
Source of Support: None, Conflict of Interest: None
The literature provides several techniques for fabricating ocular prostheses, ranging from stock to custom-made prostheses. A cosmetically acceptable ocular prosthesis is that which reproduces the colour, form and orientation of the iris and allows the patient to return to a ifestyle to which they were previously accustomed. A sequence of steps for construction of custom-made ocular prostheses is outlined in this case report with emphasis on accurate positioning of iris using a transparent graph template. Ocular rehabilitation restores the compromised aesthetics, maintains the normal physiology of the ocular area, and increases the social life and self-esteem of the patient.
Keywords: Custom ocular prosthesis, iris painting, iris positioning
|How to cite this article:|
John AV, Anilkumar S, Rajesh C, Raghavan SM. A novel technique of custom ocular prosthesis fabrication. J Oral Res Rev 2016;8:82-5
|How to cite this URL:|
John AV, Anilkumar S, Rajesh C, Raghavan SM. A novel technique of custom ocular prosthesis fabrication. J Oral Res Rev [serial online] 2016 [cited 2021 Jun 24];8:82-5. Available from: https://www.jorr.org/text.asp?2016/8/2/82/192231
| Introduction|| |
Every human being is created with a pair of eyes which serve as sense organs of sight and adds to the beauty of the face. It also performs various other functions including a very important role in nonverbal communication. Unexpected trauma, pathology or congenital deformity may necessitate a surgical intervention leading to the loss of eyeball.  Ocular disfigurement can drastically lower the victim's quality of life through its physical and psychological handicap. 
Ocular rehabilitation can be traced back to the Egyptian and Roman civilization where art eyes were manufactured from noble metals and precious stones. , The stock glass eyes gained popularity in Germany and other European nations in the eighteenth century. The severe shortage of glass eyes during the Second World War led to the use of dental acrylic resin as an alternative for ocular prosthesis fabrication which was popularized by the United States Naval Schools. 
Ocular defect can be either rehabilitated using stock eyes or custom made prosthesis. It is often tempting for clinicians to use a stock eye which can be economic, however, such a prosthesis may not perfectly adapt to the tissue bed of the eye and it usually causes significant discomfort and fails to satisfy the patient's esthetic demands. Improved esthetics is achieved only when the iris color and position is perfectly matched with the normal eye, and this is often possible only by a custom-made ocular prosthesis. 
This article presents a simple yet effective method of converting a previous stock eye shell into a well-fitting, custom ocular prosthesis with the characterization of the iris and sclera.
| Case Report|| |
A 45-year-old female reported with a complaint of ill-fitting eye prosthesis [Figure 1]. The patient history revealed that the right eye was surgically enucleated as a result of trauma 15 years back, and she was using stock eye prosthesis for the past 10 years. It was thus decided to fabricate a customized ocular prosthesis.
- The previously used stock eye was used to make the impression of the ocular defect using light body polyvinyl siloxane impression material. The eye shell was invested and the elastomeric impression material was replaced with clear heat polymerized acrylic resin [Figure 2]. The patient was asked to continuously wear the relined prosthesis for 2 weeks for maintaining the orbital volume and evaluation of fit
- Once the retention of the prosthesis was satisfactory, the relined stock eye was invested and replaced with scleral acrylic resin of appropriate shade, which matched well with natural eye sclera. Thereafter, it was acrylized to fabricate a custom scleral shell
- The diameter of the iris disc was prepared on white card paper, corresponding in size to the iridic diameter of the patient's existing eye
- The iris was manually painted using acrylic colors to customize it. Painting was accomplished in four layers: Pupil (black), stroma, collarette, and limbus with varying intensity of mixture of burned umber and yellow ochre
- A custom made clear acrylic corneal button, [Figure 3] similar to the size of the painted iris disc, was attached to it using cyanoacrylate adhesive
- The method of attaching the iris disk: The transparent graph grid was used in this method to position the iris disk. Horizontal line along the superior border of iris was to cross the vertical facial midline and marked as "O" which assisted in positioning the template subsequently
- The vertical lines coinciding with the medial and distal extremities of the iris of the natural eye were marked A and B on the left side and on the right side A' to B', at conversational gaze. Likewise, the horizontal lines referring to the inferior and superior limits of the iris were marked C, D on left and C', D' on the right side corresponding to the Y-axis, respectively. The distance between each unit on the graph was 0.5 cm [Figure 4]
- The facial markings were transferred to the graph template by placing it on the patient's face. These markings were transposed onto the side of the defect. The markings were transferred onto the acrylic scleral shell, and 1 mm of acrylic was trimmed in the marked area to create a trough to accommodate the iris button which was temporarily attached using carding wax [Figure 5]
- The custom-made iris was evaluated with the graph template. The customized iris button was permanently adhered to the scleral shell using cyanoacrylate, and the position was again verified in the patient
- Scleral characterization was done by extrinsic staining (acrylic paint) and attaching veins (red silk threads) [Figure 6]. The prosthesis was covered with a thin layer of modeling wax and further acrylized [Figure 7].
- Clear polymethyl methacrylate was packed in the mold space, and a short curing cycle for acrylization. After processing, the prosthesis was recovered from the flask for finishing and polishing [Figure 8]
- The method of prosthesis insertion and removal was taught to the patient. Follow-up evaluation was carried out once a week for the 1 st month. The color match or the iris was excellent, and the patient was satisfied with the outcome [Figure 9].
|Figure 2: Left tock prosthesis relined with polyvinyl siloxane. Right fter relining with heat cure acrylic|
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|Figure 4: Scleral shell with iris position marked. Below-hand painted iris adhered to clear acrylic button|
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|Figure 8: Left ustomized ocular prosthesis. Right reviously used stock ocular prosthesis|
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|Figure 9: Left atient before prosthesis insertion. Right atient after prosthesis insertion|
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| Discussion|| |
The recent advances in the field of maxillofacial prosthetic treatment have paved the way for a custom-made ocular prosthesis, which is superior compared with the traditional empirical method using stock shells.  Two aspects which complicate custom ocular prosthesis fabrication-iris characterization and positioning have been simplified and described in this case report.
A custom-made ocular prosthesis replicates the orientation, natural color, contour, and size of the pupil and iris, improving the esthetics and symmetry of the patient's face. , It also allows uniform distribution of volume and weight, appropriate contour, providing excellent esthetics, and easy adaptation of the patient in wearing the prosthesis. 
Various methods have been suggested for customizing the iris such as conventional painting and applying monopoly on the artificial iris, reverse painting using prefabricated caps and using digital and hard copy images of the patient's healthy eye. ,, The digital technique though reliable require complex digital photography equipment and settings, computer software as well as the patient's cooperation for the photograph are required as it is technique sensitive.  Conversely, with a detailed observation of the color, diameter, and morphological elements of the patient's natural iris under indirect natural light, custom iris fabrication can be attained just with the help of a paintbrush and oil paints.
Different methods have been suggested to determine the size and position of the iris by visual judgment,  using pupillometer,  or other callipers. Benson advocated a method of determining the size and position of the iris by visual judgment.  Since iris positioning is a technique-sensitive procedure, visual assessment alone may not be reliable and may incorporate parallax errors. Roberts suggested the use of a pupillometer for exact alignment of the pupil in the ocular prosthesis.  Pupillometer is an instrument consisting of two parallel cylinders with positive lens for locating the pupil. However, the technical difficulty of making a pupillometer available in every clinical setup is a limitation for using this method. McArthur used an ocular locator and fixed calliper for the accurate placement of the prosthetic eye in an orbital prosthesis.  The method described in this article involves an objective method for positioning the iris in a prosthetic eye which is a modification of McArthur's technique.
A transparent graph template was used to accurately locate and position the iris rather than counting on the visual assessment alone, which can introduce interobserver variability because of binocular vision and parallax errors. The method described here is straightforward and can be carried out in any clinical set-up. However, the limitation of the method described here is that in the case of facial asymmetry, accurate determination of facial midline and iris positioning will be challenging.  In such patients using pupillometer or other callipers and depending on the visual judgment of multiple observers to derive consensus should be applied. The stability of acrylic colors used for iris painting decreases with time which would necessitate refabrication of the prosthesis as aging occurs. ,,
Future is quite promising as advances are made in tissue engineering to reduce the volume of the defect using bone grafts and soft tissue grafts to restore the defect and enhance the esthetic outcome in large tissue defects.  Furthermore, early detection of cancer cells will go a long way in prevention and accurate determination of prognosis of cancer by identifying cannibalistic behavior of tumor cells. 
| Conclusion|| |
The success of an ocular prosthesis is determined by the customization of iris color along with the accurate positioning of the iris disc assembly. The technique described here has attempted at positioning the iris, virtually eliminating the subjective errors arising out of visual illusion by using a transparent graph template. The patient satisfaction and acceptance were further improved using manual paint on technique for characterization of iris and sclera.
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]