Rehabilitation of an adolescent patient’s anophthalmic cavity with customized ocular prosthesis: a clinical report

The absence of an eyeball results in physical, psychosocial and functional alterations on an individual. Therefore, rehabilitation procedures are essential to repair the patient’s self-esteem, self-confidence and physiological features. The aim of this study is to describe a case of ocular prosthetic rehabilitation in a pediatric patient. A female teenager, 17 years old, was referred to the maxillofacial prosthetic clinic to replace her former prosthesis fabricated two years ago. The new ocular prosthesis was confectioned with termopolymerizable acrylic resin and hand painted with acrylic paint on a colorless acrylic ocular bottom. The prosthesis was installed and the instructions were explained. In teenage patients the prothesis must be elaborated as soon as possible with periodic replacements in accordance with the growth period. The awareness of legal guardians and patients is essential to the success of the treatment in pediatric patients. In the present case, the patient was satisfied with the aesthetic and functional outcome.


Introduction
The loss of an eye ball affects multiple areas of an individual's well-being related with the decrease of visual capacity, facial disfigurement, psychological stress and social rejection (Artopoulou, et al., 2006).
The main causes of eye removal are intraocular tumors and ocular trauma (Raizada, et al., 2011). Depending on the severity of the situation, the treatment approaches include different surgical procedures, such as enucleation, evisceration and exenteration of the eye. Enucleation consists on the removal of the entire globe and a portion of the optic nerve, but the muscles and orbital content remain intact. Evisceration involves removal of the intraocular contents of the globe leaving the sclera and the surrounding structures undisturbed. Exenteration is more invasive because it involves removal of the entire orbital contents including the muscles, nerves, eyelids, and the surrounding tissues within the orbit (Bartlett & Moore, 1973;Jamayet, et al., 2013).
After the surgical procedures, it is important to go through a rehabilitation to recreate the appearance of a healthy eye and the surrounding tissues (Jain, et al., 2010). With the evolution of ophthalmic surgery and ocular prosthesis, replacement of an eye has become easier and more effective (Raizada, et al., 2011). The objectives of an ocular prosthesis are to maintain and protect the anophtalmic cavity, partially recover the lachrymal position, prevent the accumulation of lachrymal fluid in the eye cavity, recover facial aesthetics and enhance the self-esteem of the patient (Parr, et al., 1983;Goato, et al., 2009).
Specifically, in pediatric and teenager patients, ocular prosthesis are important to prevent cosmetic deformities and facial asymmetries and to promote an adequate orbital growth preventing psychological problems (Kennedy, 1992). However, it is necessary to replace or modify the prosthesis within a period of 18 to 24 months in order to give continuous stimuli to the socket growth and follow the development of the surrounding tissues (Raizada, et al., 2011;Yago & Furuta, 2001).
The aim of this study is to report a case of ocular prosthetic rehabilitations in a teenage patient.

Methodology
A 17-year-old teenager sought the service of the maxillofacial prosthetic clinic of School of Dentistry of Ribeirão Preto, University of São Paulo for the confection of a new custom-made ocular prosthesis on the left eye. The patient lost her eye due to a tumor when she was two-months-old and had received another prosthesis in the past. Her first ocular prosthesis was installed when she was 10 years old and then she changed that prosthesis when she was 12 years and another time when she was 14 years.
The patient's main complaint was related to an aesthetic inadequacy of the prosthesis she had used for two years.
Clinical examination of the face indicated facial asymmetry and that prosthesis was not providing adequate eyelid support because of the growth that the patient presented throughout the years. Examination of the socket revealed healthy conjunctival lining and absence of infection ( Figure 1).
The acrylic sclera was evaluated on the patient's eye socket and its contours, convexity and lid movements were observed ( Figure 4). The pattern's volume and superior contour were insufficient, so a layer of wax was added to the surface and superior margin of the sclera. After the volume recovery, contour adequacy and functionality of eyelid movements, a symmetrical point based on the pupil of the natural eye was marked on the acrylic sclera ( Figure 5).   For the iris characterization, the iris of the right eye was measured and photos were taken to aid the painting of the prosthesis. A colorless acrylic ocular bottom was selected and reduced until it reached a diameter of 11 mm. Then it was manually painted with a mix of acrylic paints (Figure 7). The iris was glued, with acrylic resin in the same color of the sclera. The acrylic resin that corresponds to the sclera was worn in 3-mm in its entire surface with one trunk-conical drill, preserving the margin of the iris and of the outer edge. Red silk fibers were adhered to the acrylic resin using a mixture of polymer and monomer (Classic, São Paulo, SP, Brazil) in a 1:10 ratio (more or less) to contribute to a natural appearance of veined sclera   Source: Authors.
The patient was instructed on an insertion and removal technique. With regards to the hygiene procedures, she was instructed to wash her hands with neutral soup, remove the prosthesis from the anophthalmic cavity, apply a drop of soap on the prosthesis surface, rub it with her finger for one minute and rinse under running water; wash and rinse the face with soap, wash the cavity with plenty of water, and then insert the prosthesis into the anophthalmic cavity. In addition, the patient was instructed not to rub their eyes and, if necessary, to drip the saline into the anophtalmic cavity without removing the prothesis. Further follow-up was done after 2 weeks and it was recommended that the patient change the prosthesis once every 2 years.

Results and Discussion
Different conditions can result in the loss of an eye-ball including congenital defects, irreparable trauma, tumors, painful blind eye, sympathetic ophthalmia or the need for histological confirmation of a suspected diagnosis. In those situations, the replacement of the lost eye should occur promptly in order to promote physical and psychological healing for the patient and to improve social acceptance (Artopoulou, et al., 2006). A multidisciplinary team is fundamental to provide accurate and effective rehabilitation of the patients. Each professional has a certain role depending on the specifications of the clinical condition.
Overall, oncologists, ophthalmologists and surgeons are responsible for the diagnosis, treatment planning and surgical procedures. Whereas, the maxillofacial prosthodontists and technician are in charge of the confection of the prosthesis. Therefore, combined efforts along all the phases of the treatment are essential to achieve a long lasting solution for the patient's need (Bartlett & Moore, 1973).

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Research, Society and Development, v. 10, n. 10, e287101018692, 2021 (CC BY 4.0) | ISSN 2525-3409 | DOI: http://dx.doi.org/10.33448/rsd-v10i10.18692 An ideal prosthesis must restore the normal opening of the eye, provide eyelid support, be adequately retained and aesthetically pleasing and, if possible, restore a degree of eye mobility (Jamayet, et al., 2013). These conditions can be best achieved when rehabilitation occurs right after the loss of the eye.
In the present study, a new ocular prosthesis was fabricated in a young patient whose former rehabilitation was esthetically and functionally inadequate. Specially in patients during growth periods, the regular change of the prosthesis is mandatory in order to maintain steady contact with the cavity, to give continued stimulus to the socket growth and surrounding tissues (Bartlett & Moore, 1973). Periodical chances of ocular prosthesis are essential because the constant rate of the facial growth results in a loss of ocular prosthesis adaptation and, as a consequence, the eyelid support reduces.
Ideally, in the early childhood, the prothesis must be elaborated as soon as possible with periodic replacements in accordance with the growing age since the orbital volume increases in a constant rate (Yago & Furuta, 2001;Anson, et al., 2004;Bentley, et al., 2002). In this particular case, the patient already presented a facial asymmetry probably associated with the fact that she only received an ocular prosthesis ten years after the surgical removal of the eye. Moreover, the first prosthesis was used during a long period without any modifications or replacements.
Unfortunately, the delay in the care occurs more frequent than the ideal situation. The lack of communication between the health providers with each other and with the patient or his/her legal guardian may be one of the reasons that contribute to this event. Besides, still there is misinformation related to this type of treatment, particularly in pediatric cases, since many patients and professionals aren't aware of the necessity of constant prosthesis modifications. Also in some places, there aren't specialized centers or professionals that perform these category of treatment. As a consequence, many patients with unrestored anophthalmic sockets exhibit growth retardation which can lead to facial disfigurement (Agrawal, et al., 2012).
The prosthesis can be pre-fabricated or custom-made. The customized prosthesis presents better functional and aesthetic results because it contributes to a better mobility, pressure distribution and better fit in the anophthalmic cavity (Bonaque-González, et al., 2015). These prostheses can be fabricated through a conventional or digital workflow. The association of available technology, such as computer aided design and rapid manufacturing technology, produces more comfortable prosthesis in a lesser time (Alam, et al., 2017). Successful cases of digitally designed and printed iris were described on the literature (Farook, et al., 2019). However, the conventional methods are more accessible and were employed on the present case.
The literature provides several techniques and materials for the fabrication of customized prosthesis (Goiato, et al., 2014;Monkey, et al., 2018;Kulkarni, et al., 2018;Maskey, et al., 2019). Among the materials described, glass and methyl methacrylate resin are the most employed. However, glass isn't the first option as it is fragile and can suffer surface deterioration from contact with orbital fluids (Erpf, 1953). For that reason, nowadays, methyl methacrylate resin is more used because of its superior biocompatibility, aesthetic characteristics, good cleanability, durability, reliable mechanical retention, adaptability of form, low cost and availability (Ogawa & Hasegawa, 2005).
Different ocular impression techniques have been proposed to provide a precise register of the topography of the eye socket (Patil, et al., 2008;Mathews, et al., 2000). These techniques can be subdivided into different categories, such as: direct or external impression; impression with a stock, modified stock or custom tray; and wax scleral blank technique. The main impression materials are irreversible hydrocolloids and silicones (Raizada & Rani, 2007) . The technique and material choice depending on the operator's ability and preference. In this case, a direct technique using condensation silicone ejected in the cavity with a syringe was used, which provided a precise copy of the ocular defect.
With regard to the fabrication of the sclera pattern, wax or acrylic resin can be used. Due to its properties, such as polishing, the acrylic resin is preferred since it is more comfortable for the patient and also allows better size and contour evaluation (Cevik, et al., 2012).
An accurate iris reproduction is a critical stage during the fabrication of an ocular prosthesis (Goiato, et al., 2019).
Several methods can be used to replicate the natural iris including manual painting, reverse painting using prefabricated caps and use of digital images of the patient's healthy eye (Buzayan, et al., 2015). The manual iris painting technique using acrylic paint in prefabricate caps, as used in this case, has the advantage of providing natural-like characteristics and adequate color stability (Raizada & Rani, 2007;Walshaw, et al., 2018). However, it depends on the operator's artistic skills and can be more time-consuming. Furthermore, the correct positioning of the iris is also important. In order to establish a realism, symmetry and a naturalappearing gaze, it is necessary to guarantee a precise duplication of size and location of the iris. Different technics can be used.
In this case, light reflection viewed symmetrically in the natural eye was used as an auxiliar way to visually determine the pupile position. So the patient fixed his gaze on a predetermined object and it was possible to confirm the position compared to the contralateral eye. But the use of auxiliar devices may be helpful to determine the iris orientation. Several tools have been described in the scientific literature, such as: the use of a pupillometer, a plastic strip template, a millimeter rule, an ocular locator and fixed caliper, inverted anatomic tracings, a Boley's gauge, a transparent graph grid, computer simulation approach with optical scanning technique, computer-aided design, a customized scale and also pupillary distance ruler Manvi & Ghadiali, 2008;Malik, et al., 2014).
The awareness of legal guardians and patients is essential to the success of the treatment in pediatric patients. It is imperative that they recognize the need to rehabilitate the anophthalmic cavity right after the surgical intervention and to constantly replace the ocular prosthesis at most every two years (Bonaque-González, et al., 2015). Furthermore, periodical follow-up appointments are crucial to evaluate the prosthesis, its adaptation to the surrounding tissue, the presence of associated pathologies and the patients' satisfaction.
Several studies have described the success of the early treatment on anophthalmic pediatric patients and confirmed the importance of continual monitoring and constant modification of the ocular prosthesis (Stah, et al., 2015;Santos, et al., 2017;Pavaiya, et al., 2010). These articles concluded that in order to promote an adequate facial development and contribute to the construction of the patient's psychological and social features the prostheses have an utmost importance. Not only that, it is necessary to determine periodical ocular prosthesis changes along the whole period of craniofacial growth to minimize the possible discrepancy between the compromised and the health sides (Agrawal, et al., 2012).
In that manner, ocular rehabilitation will successfully restores the compromised aesthetics, increase the social life and self-esteem of the patient. In addition, these prosthesis maintain the normal physiology of the ocular area since they prevent possible complication such as ulcers, tissue retraction, severe orbital defects, eyebrow and eyelids drooping; restore tear dynamics; and even promote increased electrical activity of orbicularis oculi muscle (Goiato, et al., 2013;Goiato, et al., 2015).

Conclusion
Rehabilitation of pediatric and teenager patients with an ocular prosthesis is a challenge due to the continuous physical and psychological development during the growth period. Hence, the multidisciplinary team must execute a closer follow-up.
The outcome of the present case was considered successful as the patient was satisfied with the aesthetics and comfort of the prosthesis.