FABRICATION OF OCULAR PROSTHESIS - A COMBINATION OF A STOCK AND CUSTOM MADE PROSTHESIS- A CASE REPORT

An ocular defect may affect a patient psychologically and an ocular prosthesis is given to uplift the patient psychologically and improve the confidence. Defects of the eye may follow the removal of a part of or the entire orbit. This results in the patient becoming visually and psychologically handicapped. Restoring the defect with a prosthesis not only restores esthetics but also gives back the lost confidence to the patient. This is a case report of a patient with a prosthetic eye fabricated by the combination of a stock eye and a custom ocular prosthesis.


ISSN: 2320-5407
Int. J. Adv. Res. 8(11), 554-559 555 retention of the prosthesis. So, it was decided to replace the missing eye with a combination of stock eye and custom made ocular prosthesis. The consent of the patient was taken for the procedure.

Impression Tray Selection:
""Chalian stated that the prefabricated resin eye should not be used in eviscerated/ enucleated socket as intimate contact between ocular prosthesis and tissue beds is needed to distribute pressure equally". Hence, the procedure was initiated by selecting and modifying a pre-fabricated stock eye, whose iris and pupil closely matched that of the natural eye of the patient, to comfortably and loosely fit the socket (Fig-2). Andit was thereafter used as a conformer or tray for impression making. The patient was asked to be in a relaxed position to provide a natural drape of tissues.

Impression:
The patient was made to look straight and keep all facial muscles relaxed. A light bodyimpression material was injected into the impression tray with a syringe. It was slowly filled intothe defect to prevent overfilling. A little amount flowing outthrough the inner canthus indicates adequate material filling ofthe socket.The impression was gently removed first by massaging the lowerlid downwards and away from the nose first and then sliding theimpression out from the upper eyelid in an arc like path. Theimpression was then washed and disinfected.

Making a Wax Pattern:
A silicone putty index was made of the impression (Fig-3). Onceit set, it was cut open and wax was flown through it. Onhardening, the wax pattern was gently retrieved, cooled incold water, and smoothened with the help of a carver and gauze.The tissue surface of the wax pattern was not manipulatedat this stage. This stock eye-wax pattern combination was tested in the socket and modified for the adequacy of ocular movements, correction of pupillary alignment, proper palpebral movements, scleral contour, and convexity. It was also checked for fit, comfort, bulkiness of the pattern, and drape and mobility of the eyelids. Necessary adjustments were made.Corneal prominence was checked for, by standing behind thepatient, retracting her eyelids and making her look downward.Then the adjusted and modifiedstock eye-wax pattern combination was invested, flasked (Fig-4), and dewaxing was done. Red silk fibers to mimic veinswere placed in the dough of the determined acrylic shade followed by curing, (Curing protocol: A modified curing protocol, referred to as "reverse curing" as has been reported by Jorge and co-workers 5 was followed to minimize monomer content water at 95°C for 20 minutes and thereafter in boiling water for an additional 20 minutes.) finishing, and polishing.Rough edges of the prosthesis were trimmed off. It was polished with the help of polishing burs, pumice and a buff to give the prosthesis a natural glossy finish (Figure-5).
Prior to insertion of the finished prosthesis, it was disinfected using 70% isopropyl alcohol and 0.5% chlorhexidine solution. After thoroughly cleaning the prosthesis with saline solution to prevent chemical irritation, it was inserted and checked for fit, contour, and movements (Fig-6). Minor adjustments were made at the time of delivery asper the patient"s comfort and esthetics.The patient was taught how to place and remove the prosthesis. Necessary instructions for cleaning, placement, and removalof the prosthesis were given and the need for regular recallappointments was emphasized. 6 Repolishing of the prosthesis may be required on a timely basis and this was explained to the patient.

Discussion:-
The prosthesis, though not functional, is a very suitable esthetic replacement for such patients. It restores self-confidence in patients and prevents social embarrassment. Two options are available for artificial eye prosthesis, one is apre-fabricated ocular prosthesis and the other is custom-made.Pre-fabricated prosthesis carries potential disadvantages ofpoor fit (which endangers the eye to granuloma formation),poor esthetics and poor eye movements. 6 Custom-madeprosthetic eye fabrication involves complex paintingprocedures in various stages that are quite difficult and basedpurely on the painting skills of the operator. 7 The technique to fabricate ocular prosthesis in these case reports modifies a pre-fabricated eye prosthesis to a custom-made fit andesthetics. This helped us to overcome the disadvantages ofpoor fit, esthetics, and movement of a prefabricated prosthesis and complex painting procedure and technique involved inmaking a custom-made ocular prosthesis.This technique would also be relatively easy to perform,along with saving on laboratory time.
According to Beumer et al., 8 intimate contact between the ocular prosthesis and the tissue bed is needed to distribute even pressure, so a prefabricated prosthesis should be avoided. Moreover, the voids in the prefabricated prosthesis collect mucus and debris, which can irritate mucosa and act as a potential source of infection, which are minimized in custom-made prosthesis. 9 Limitations of the technique are that the clinician isdependent on the availability of a pre-fabricated eyewith properly matching iris and pupillary part. Also, thelong-term color stability of the heat-cured acrylic and thestrength of its union with the stock eye will have to beclosely evaluated.

Conclusion:-
A prosthetic eye is useful in patients with scleral defects and helps restore esthetics. It also goes a long way in completing psychological rehabilitation in situations where loss of vision is permanent. The goal is to return the patient to the society with a normal appearance and reasonable motility of the prosthetic eye. The artificial eye is a triumph of resourceful human ingenuity, and a tribute to the unique enduring spirit that persists in the desire to prevail over adversity. The next time you gaze into an unseeing eye, you just might see a happy SMILE FACE painted where the iris ought to be!