1 Introduction

Eyes are the first feature of the face to be noticed and are vital organs for vision. The unfortunate loss or absence of an eye may be caused by a congenital defect, pathology or trauma to eye and sometimes, iatrogenic removal of eye secondary to some pathoses or, trauma to the tissues in and around the eye, too, may necessitate surgical intervention resulting in the removal of the eye (Artopoulou et al., 2006). Loss or absence of an eye not only causes loss of sensory function but also, s significant cosmetic disfigurement which gives unaesthetic look and has a psychological effect on the patient (Lubkin and Sloan, 1990). Thus, in such cases, prosthesis becomes mandatory to raise the spirits and ease the mind of the afflicted individuals. A multidisciplinary management and team approach are essential in providing an accurate and effective rehabilitation and follow-up care for the patient (Brown, 1970). Therefore, the combined efforts of the ophthalmologist, the plastic surgeon and the maxillofacial prosthodontist are essential to restore the patient’s quality of life. The prosthodontist can manage the aesthetics related to the lost eye by replacing it with different maxillofacial materials.

2 Review of Literature

The fabrication of eyes is not limited to the modern age. They have been used for centuries, with the earliest known examples found in mummies dating back to the fourth dynasty in Egypt (1613-2494 BC) when eye replacement used to happen by using precious stones, earthenware, enameled bronze, copper and gold in the shrunken sockets. Ambrose Pare, a French Dentist of the 16th century is considered as the pioneer of modern artificial eyes. He used glass and porcelain to fabricate artificial eyes (Allen and Webster, 1969). Glass remained the most popular material until the advent of World War II, when it was difficult to obtain glass or glass eyes from Germany. Later, methyl methacrylate, which had replaced vulcanite as denture base material, seemed to be a good replacement material. Naval Dental School (1940) tested the use of acrylic resin in fabricating a custom-made ocular prosthesis. In 1944, by the combined efforts of the individuals of the Armed Forces of the United States, methyl methacrylate resin was successfully used for the fabrication of the ocular prostheses. Since then, usage of resin gained popularity because of its light weight, translucency, better fracture resistance, ease of fabrication, easy adjustability and its capability for intrinsic and extrinsic coloring. Unlike a glass eye, an acrylic eye was easy to fit and adjust, was unbreakable, inert to ocular fluids, esthetically good, longer-lasting and easier to fabricate. Today, a vast majority of patients all around the world wear ocular prosthesis made of acrylic resin. Various methods of rehabilitating an ophthalmic socket include stock eye prosthesis (Pre-fabricated) and custom-made (Benson, 1977) ocular prosthesis (Benson, 1977; Murphey and Schlossberg, 1944; Dyer, 1980).

3 Case Report

A 35-year old male patient reported to the Department of Prosthodontics and complained of facial disfigurement due to the loss of left eye. (Figure 1) A history of severe eye infection followed by enucleation was recorded. Consequent to this, the patient suffered severe emotional trauma in terms of facial aesthetics and social acceptance. The patient, therefore, was seeking artificial eye replacement. Examination of the orbital socket revealed a healthy conjunctiva with no signs of infection or inflammation, covering the posterior wall of the an-ophthalmic socket, showing synchronous movements. Patient was economically compromised, So implant retained prosthesis was not a choice. To get better aesthetics and color matching without following the conventional pre-fabricated eye shells, a custom-made acrylic resin based, ocular prosthesis was planned and the treatment procedure was explained to the patient. As the patient gave consent, the treatment was started.

3.1 Steps of Fabrication

3.1.1 Impression of ocular socket

Petroleum jelly was applied to the surrounding area of eye and eyebrows for easy removal of the impression when it had set. A thin mix of an irreversible hydrocolloid (Algitex, Dental Products of India, Mumbai, India) was injected in an-ophthalmic socket using a disposable syringe. After loading in the socket, a loop of 19-gauge orthodontic wire was used to support and hold the impression (Artopoulou et al., 2006; Brown, 1970). The patient was asked to move his normal eye in all directions to allow the irreversible hydrocolloid to flow into all areas of the enucleated socket. Then, the patient was instructed to stare in a straight direction till the material had set. After the material had set, the assembly was removed and the impression was examined for defects and voids. (Figure 2) After confirmation of acceptability of the impression; it was poured with dental stone (Type III Dental stone, Kalstone, Kala Bhai Pvt Ltd., Mumbai, India) by two pour cast technique i.e. in two parts with the second part being poured after applying lubricant and making orientation grooves on the partially set first half. The master cast was lubricated with a separating medium. After this, modeling wax (Deepti Dental Products, Ratnagiri, India) was melted and poured in the ocular socket on cast. (Figure 3) After the wax became hard, the wax pattern was removed from the cast and was checked for any air entrapment and irregularities (Figure 4).

Figure 2 Impression of the ocular socket

Figure 3 Fabrication of wax pattern

Figure 4 Wax Pattern

3.1.2 Wax scleral try-in

Wax pattern was placed in the patient’s the ocular socket. A protective blepharospasm was observed when the wax pattern was first placed in the socket, thus we waited until the spasm relaxed (Kumar et al., 2014). Wax pattern was checked for its extensions, contour, proper fit, opening and closing movement of the eyelids with movement of the wax pattern in up, down, lateral and circular directions. Excess wax was removed from the pattern and again, all the movements were checked until satisfactory contours for the socket and eyelids were obtained (Cain, 1982). The position of the iris-pupil area of the natural eye in relation to the inner canthus and the upper and the lower eyelids were transferred to the wax pattern. The center and the peripheral area of the pupil were marked on the wax pattern with the help of a probe. The wax pattern was removed from the socket; the markings of the pupil were sharpened by making grooves of the periphery and the center of the pupil with the help of a carver. (Figure 4) Again the pattern was inserted in the patient’s ocular socket and checked for the visibility of sclera, extensions of the pupil and the center of the pupil by comparing the same with the natural eye of the patient (Bartlett and Moore, 1973). As try-in was completed, the wax pattern was flasked and dewaxing done. (Figure 5) The next step was to reproduce scleral shade of the normal eye. For this, shade tabs were prepared by mixing and matching different shades and proportions of the tooth-colored acrylic (Heat cure, tooth colored acrylic resin for crown and bridge work, DPI, India) till the color of the sclera of the other eye was replicated. Shade B2 was selected and packing done.

Figure 5 Post-dewaxing

3.1.3 Fabrication of resin sclera

The acrylic resin was bench polymerized for 5 minutes and then, placed in boiling water at 210 degrees F for 30 minutes (Artopoulou et al., 2006). After the completion of curing, the acrylic eyeball was finished and polished. (Figure 6)

Figure 6 Heat cure acrylic Scleral blank

3.1.4 Photograph of adjacent natural eye

A high quality digital photograph of the patient’s contra-lateral natural eye was obtained using a DSLR camera (Nikon D3200 with the 18-55 mm lens). (Figure 7) The image obtained was edited and three sizes were cropped viz.11 mm,12 mm and 13mm in the image editing software; Adobe Photoshop CS5. (Adobe Systems Inc.). Different combinations of brightness and contrast were used to produce a variety of images so as to match the patient’s eye perfectly at the time of try-in. (Figure 8)

Figure 7 Image of adjacent natural eye of patient

Figure 8 Photos of the iris in different sizes and different grades of brightness

3.1.5 Trial of processed resin sclera

When the prosthesis was placed in the socket, the orbicular muscle was allowed to relax for at least 10 minutes to permit critical evaluation (Kumar et al., 2014). The prosthesis was checked to fulfill all the criteria as done at the time of wax trial. (Figure 9) 1mm of acrylic was then removed from the iris portion of the eyeball on the frontal surface in the palpebral fissure area.

Figure 9 Try-in of sclera blank

3.1.6 Customization of the iris and characterization of sclera

The modified images were printed on a photo paper. After a satisfactory try-in of the scleral blank, the images printed on the paper sticker were placed one by one in the area which was reduced by 1 mm and matched against the natural eye of the patient. The image that simulated the appearance perfectly, was selected and pasted on the scleral blank with the help of cynoacrylate adhesive (Fevikwik, Pidilite Industries Ltd. Mumbai, India) to confirm the position and appearance in the patient.

3.1.7 Characterization of sclera bank

With the help of color pencils, the circular area surrounding the iris was, then, colored with a bluish outline and patches of melanin pigmentation with brown color, to resemble the appearance of natural adjacent eye, were produced. Red colored microfibers of veined acrylic powder were used to give the appearance of blood capillaries. (Figure 10,Figure 11)

Figure 10 Characterization of sclera

Figure 11 Characterization of sclera

3.1.8 Final finishing and polishing of the prosthesis and insertion

The image and the surrounding area on the sclera blank was then covered with clear, self-cure acrylic resin (Trevalon Clear, Dentsply India Pvt. Ltd., Gurgaon, India) and allowed to set. The prosthesis was finally finished with the help of a carbide bur and a sand paper and polished with a polishing cake to get an even gloss. (Figure 12) Insertion of prosthetic eye was done and the patient was given instructions. (Figure 13)

Figure 12 Custom-made ocular prosthesis

Figure 13 Custom-made ocular prosthesis

3.1.9 Post-Insertion Instructions

Patient was advised to clean the eyelashes on periodic intervals and to keep them free from mucous build-up, to clean the prosthesis with sterile water and rinse it with saline solution or boric acid solution, to use lubricant solution, Carmellose sodium, 5 mg/ml (Refresh teardrops) that helps the prosthesis to be kept moist and smooth and advised review visits with the ophthalmologist for needful (Taylor, 2000). Patient was informed that in time, the surface of the prosthesis may become scratched or pitted, resulting in foreign body sensation, so, a periodic follow-up was very important (Cain, 1982).

4 Discussion

Custom-made, ocular prosthesis could be of either glass or methyl methacrylate resin. Glass is not the material of choice as it is subject to breakage and surface deterioration from contact with the orbital fluids (Artopoulou et al., 2006). Methyl methacrylate resin is superior to other ocular prosthetic materials in terms of tissue compatibility, aesthetics, durability, adaptability of form, cost and availability (Brown, 1970; Kumar et al., 2014). The close adaptation of custom-made prosthesis tends to distribute pressure more equally than does stock eye prosthesis, thereby, reducing the incidence of abrasions or ulcerations. It, also, enhances tissue health by decreasing potential stagnation spaces at the prosthetic tissue interface (Mathews et al., 2000; Dyer, 1980; Benson, 1977; Taicher et al., 1985). A properly-fitted and acceptable custom-made ocular prosthesis also has characteristics like it retains the shape of the socket defect, prevents collapse and/or loss of shape of the eyelids, provides proper muscular action of the eyelids, prevents accumulation of fluid in the orbital cavity, maintains palpebral opening similar to the natural eye and mimics the color and proportions of the natural eye (Taylor, 2000). In this case, a  photograph of the iris of patient’s natural eye was used, so, the time consumed for the characterization of the iris also got reduced as only sclera blank was characterized, thus, overcoming  the only disadvantage of the regular, custom-made ocular prostheses.

Conclusion

This case report demonstrates a simple and innovative technique for the fabrication of custom-made ocular prostheses in an attempt to avoid the time consuming and expensive procedures that are required in other methods. An ocular acrylic prosthesis was fabricated using the advantages of digital photography, which had an acceptable fit, retention and improved aesthetics alongwith a certain degree of motility in coordination with the contra-lateral normal eye. Thus, an acrylic custom-made ocular prosthesis replacement is a good alternative to promote physical and psychological healing in such patients and to improve their social acceptance.

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