Ординатура / Офтальмология / Английские материалы / Surgical Atlas of Orbital Diseases_Mallajosyula_2009

Figure 22.1K: The skin and subcutaneous tissues are incised up to the level of the periosteum

Figure 22.1M: The periorbita is separated from the bone superiorly, laterally and inferiorly first using the blunt end of the periosteal elevator or a lens spatula. The periorbita is firmly attached to the bone near the orbital rim and loosely within the bony orbit. Medially the lacrimal sac is elevated and cut near the nasolacrimal duct

Figure 22.1L: The periosteum is cut about 6 mm from the orbital rim and elevated using the periosteal elevator

Figure 22.1N: Near the orbital apex, the tissues are clamped with a curved artery forceps before cutting the apical stump

Figure 22.1O: The exenterated contents are dark brown in color suggestive of a melanoma

Figure 22.1P: 6/0 vicryl sutures are used to suture the subcutaneous tissue once hemostasis has been achieved

Figure 22.1Q: The skin is closed with 6/0 prolene

Case 2

A 40-year-old male presented to us with eccentric protrusion (outward and lateral displacement) of the left eye which was gradually increasing for last 4 months (Figure 22.2A). A non-tender mass, firm to hard in consistency was palpable deep in the superior and nasal part of left orbit. There was no apparent nasal or paranasal sinus pathology. On presentation, he had best corrected visual acuity of 6/7.5 and 6/12 in right and left eyes respectively. Ocular movements in the left eye were grossly restricted; adduction more than abduction. Anterior segment examination was unremarkable in both eyes. Fundus in the right eye was normal and in the left eye showed presence of early disc edema. The patient was non-diabetic and non-hypertensive. Ultrasound B scan of the left eye revealed diffuse thickening of medial rectus with maximum diameter being 14.3 mm. CT scan showed presence of a fairly well defined, uniformly isodense, intraconal mass located between medial rectus and optic nerve. Medial rectus could not be appreciated separately from the mass posteriorly (Figures 22.2B and C). An excision biopsy by a lid split medial orbitotomy approach was done. Postoperatively his proptosis was reduced but the vision in left eye was reduced to PL with inaccurate projection of rays, and he had grade 1 relative afferent pupillary defect.

Histopathology of the biopsy specimen showed presence of giant cells and elongated budding fungal filaments. Microbiological evaluation confirmed a diagnosis of aspergillosis.

Figure 22.2A: A 40-year-old male presented to us with progressive proptosis of the left eye of 4 months duration

B

C

Figures 22.2B and C: CT scan revealed the presence of a fairly well defined uniformly isodense intraconal mass between the medial rectus and optic nerve

4 months later the patient came back with exacerbation of proptosis with a firm mass palpable in the medial canthal region (Figure 22.2D). Exophthalmometry readings were 19 and 30 mm in the right and left eye respectively. He had no vision in the left eye at this visit. CT scan showed a solid mass, which was filling almost the entire orbital cavity; extraocular muscles could not be made out separately from the mass (Figures 22.2E and F). The mass could be seen extending up to the superior orbital fissure. Lateral wall of orbit showed excavation of bone. Contiguous middle cranial fossa and paranasal sinuses appeared uninvolved. Lid sparing exenteration was done in view of extensive nature of disease.

Orbital Exenteration 325

Figure 22.2D: 4 months later the patient came back with exacerbation of proptosis and a firm palpable mass in the medial canthal region

Figure 22.2G: Periodic acid schiff (PAS) stain (400×) showed the presence of dark filaments confirming the diagnosis of aspergillus flavus

Figure 22.2H: Gomori’s methanamine silver (GMS) stain showed of dark filaments aspergillus flavus

326 Surgical Atlas of Orbital Diseases

Figure 22.2I: 3 months postsurgery the skin wound had healed and the patient did not show any signs of recurrence

Histopathology of the exenterated specimen revealed multiple septate branching fungal filaments within the giant cells and stroma. There was no definite evidence of vascular invasion. There was no involvement of the globe. Microbiology confirmed the presence of Aspergillus flavus [Figure 22.2G periodic acid schiff (PAS) stain showing the dark filaments and Figure 22.2H Gomori's methanamine silver (GMS) stain showing the dark filaments against a green background] in the exenterated orbit.

The patient was maintained on oral antifungals and was stable with no recurrence till last follow up 3 months postsurgery (Figure 22.2I).

REFERENCES

1.Bartische G Ophthalmodouelia, das ist Augendiest. Dresden, Matthes Stockwell, 1583; 217-19.

2.Golovine SS Orbitosinus exenteration. Ann Ocul 1909;141:413-31.

3.Nowikoff V Extirpation of the orbit. Lyon Chir 1927; 26: 17-27.

4.Wheeler JM The use of epidermic graft in plastic eye surgery. Internat Clin 1922; 3:292-300.

5.Shields JA, Shields CL, Demirci H, Honavar SG, Singh AD Experience with eyelid-sparing orbital exenteration: the 2000 Tullos O. Coston Lecture. Ophthal Plast Reconstr Surg 2001;17(5):355-61.

6.Donahue PJ, Liston SL, Falconer DP, Manlove JC. Reconstruction of orbital exenteration cavities. The use of the latissimus dorsi myocutaneous free flap.Arch Ophthalmol. 1989; 107(11):1681-3.

7.Uusitalo M, Ibarra M, Fulton L, Kaplan M, Hoffman W, Lee C, Carter S, O'Brien J. Reconstruction with rectus abdominis myocutaneous free flap after orbital exenteration in children. Arch Ophthalmol. 2001; 119(11):1705-9.

8.Bonavolonta G Frontalis muscle transfer in the reconstruction of the exenterated orbit.Adv Ophthalmic Plast Reconstr Surg. 1992; 9:239-42.

9.Arlyan S, Cuono CB.Use of the pectoralis major myocutaneous flap for reconstruction of large cervical, facial or cranial defects. Am J Surg. 1980;140(4):503-6.

INTRODUCTION

Loss of an eye has a very traumatic effect. It leads to loss of self belief, can make the patient and family very depressed. Eye to eye contact is very important in conversation, which is usually lost if the person has a very disfiguring eye or an empty socket. They seek aesthetic improvement in their cosmetic appearance. Patient's rehabilitation with prosthesis is very challenging, especially when it is a facial prosthesis where a natural looking prosthesis is the final goal.

Orbital prosthesis and ocular prosthesis deal with the fabrication of an artificial substitute for different kind of orbital deformities, which can be due to diseases, surgery, trauma or congenital malformation. Several cases of devastating facial injuries, incurred in battle, were treated in the early nineteenth century with indigenous appliances and these reconstructive procedures gave definite push to the field of facial replacement.1 Great strides in the field have been made in the past decades.

Orbital Prosthesis

Orbital prosthesis is meant for the face to improve the cosmetic appearance of the individuals and most often it is required in conditions where there is an additional loss of periocular tissues like eyelids, eyelashes and eyebrows.3 While fabricating an orbital prosthesis utmost care should be taken to not only replace lost periocular tissue but also to match them in terms of color and texture to the surrounding tissues and the fellow orbit.

Types of Prosthesis

•Orbital Complete

–Spectacle mounted prosthesis

–Adhesive retained prosthesis

–Magnetic retained prosthesis Partial

–Adhesive retained prosthesis

Complete prosthesis: means prosthesis with not only an ocular prosthesis but also it contains eye lids, eye brow and eye lashes, to restore the normal anatomical appearance to the patient.

On the basis is retention it can be further classified.1-4,8

Spectacle mounted prosthesis: is used in conditions where surface remains moist and a silicon prosthesis is not going to stay. A facial prosthesis made up of acrylic can be attached to spectacle, can be an option for such kind of cases.

Adhesive retained prosthesis: in conditions where surface is dry and a silicon prosthesis is going to stay. A facial prosthesis made up of medical grade silicon can be attached externally in such cases.

Magnetic retained prosthesis: this is fabricated in a very special situation where patient had radical orbital exenteration. The surface is provided with the support of magnetic anchors that helps in retaining the prosthesis.

Partial prosthesis: described in literature earlier for the nasal and auricular prosthesis. Recently Raizada et al.5-6 described the method of fabricating the partial orbital prosthesis where at first a custom made ocular

328 Surgical Atlas of Orbital Diseases

prosthesis is placed and later on the lower eyelids are designed using the medical grade silicon and then it can be retained with epithane.

Factors that Affect the Fit of an Orbital Prosthesis

There are many factors that affect the fit of an orbital prosthesis.It is important to evaluate the orbital defect and later on choosing the modalities of retaining the orbital prosthesis.

1.If the orbit had an incidence of tumors, there should be no recurrence.

2.The surface should be well healed; there should be no edema, or infected external surface if the case is of open defects like in the cases of radical orbital exenteration.

3.If it is a case of orbital trauma and severe deformity like lid coloboma, they may benefit with partial upper or lower lids prosthesis.

4.If the patient had extensive damage to the orbital cavity, a glue based prosthesis will be interfering with patient eyelids and may not be very comfortable. Such cases may be either considered for blepharorrhaphy or else an spectacle mounted orbital prosthesis with vaulted back surface.

5.If the patients have ocular disfigurement in the lower lids due to the extensive trauma and lids cannot be constructed, a partial prosthesis with integrated lower lids can be fabricated.

In this chapter I shall be discussing the technique of fabricating orbital prosthesis (a hybrid type as a complex prosthesis is made up of two different materials, so called as hybrid prosthesis).

There are many steps involved but the following steps involved fabricating an orbital prosthesis are of more concern:

•Preperation of the patient

•Impression

•Casting

•Sculpting

•Moulding

•Coloring

•Using the desired material

•Fabrication of ocular prosthesis.

Preparation of the Patient

This is a very important step as patient needs to understand what we are going to do. A proper counselling about the whole procedure makes the patient very calm, and make the work very comfortable. I believe that the more the patient understands, the better he co-operates. Explain to the patient the whole procedure using the other patient's pictures or illustrations. You can now ask the patient to lay down on a couch or bed in order to make patient completely relaxed as this is very tiring because the whole procedure takes about 30 to 45 minutes.

Impression of the Orbital Defect

Impression is taken while the patient is lying in the supine position. Vaseline is applied on the places of eyebrows, eyelashes as well as in the raw area of the defect if present.

There are many ways to take an impression. Many people believe that only defective side impression makes work much easier, but I believe that taking the impression of the whole face gives better pictures, hence forth I prefer to take the impression of both sides of the face so as to obtain accurate information about the defective as well as normal side too.

We make use of hydrophilic colloid as the basic material of taking the impression of the orbital cavity. It is not only just an impression material that is needed but you also require the reinforcing materials such as metal clips, gauge piece and the final layer of casting stone.

Prior to taking an impression of the defect, it is essential to tell the patient about the type of impression you are going to take as some time the defects are open as in case of radical exenteration, and slight mistakes give really a hard time. By using the base plate wax and adhesives like micropore tape, mark the boundary of defect. Use Vaseline on the area of the eye lashes and eyebrow, so that while taking out, the impression comes out easily. (Figures 23.1A to C)

Figure 23.1E : This is a lateral view showing how the base plate wax and micropore adhesive makes a boundary of the defect and make easier to take an

impression. Use the hydrophilic colloid in the ratio of 1:1 with water and after mixing thoroughly with the flat spatula, pour it first on the defect area and later in the surrounding tissues (Figure 23.1D). Use the reinforcing materials to make the impression so that while putting the second layer of die stone, it gets adhered to the surface and makes a stable impression (Figure 23.1F).

As hydrophilic colloid gets set very fast it is recommended that mix the die stone in ratio of 1:1 with water and pour above the hydrophilic colloid material. Meanwhile use the reinforcing material to make the die-stone mechanically strong (Figure 23.1G).

We prefer to use even gauze piece over the dye stone (Figure 23.1H), so that it get integrated with dye-stone. In about 10 minutes the die-stone gets set and exothermic reactions starts and we use mild water on the surface so that it remains cool. Once the die-stone is set, ask the patient to squeeze the face and remove the impression which is called as negative impression (Figure 23.1I).

Orbital Prosthesis 329

Casting

Casting is replicating a negative impression to positive impression, and this will reflect the defect of the patient. Stablize the impression material using the clay or sand box and slowly pour the mixture of dye-stone, step by step. Let it set for its optimal time of about 15 minutes (depends on the type of dye stone used), (Figures 23.1J to L shows the junction line of dye-stone and hydrophilic colloid from where you can separate the negative and positive impression). Remove dye-stone cast at the junction line slowly from the hydrophilic colloid and this will represent the patients deformity (Figures 23.1I and L). You should always compare the impression of the defected area and the patient's actual orbital defect. Once you are sure then only proceed ahead. (Figure 23.2A).

Sculpting

Use the tinfoil of 0.01 mm on the defect to make the model easier to take out from the cast and to check

it on the patient face (Figure 23.2B). There are various kinds of materials used such as clay, waxes or, direct silicon for sculpting model. We prefer to start the procedure with the base plate wax as it has property of moulding into desired shapes (Figure 23.2C).

Now we need to choose an ocular prosthesis for the same anterior curvature of the patient, preferably a flatter one when you have shallow defect of the orbit (Figure 23.2D). By using the Purkinje's images of the fellow eye and measuring the inter pupillary distance (distance from the mid line of face to the center of the fellow eye) to locate the exact corneal reflex and even the use of hurtle exophthalmometer for assessing the exact amount of proptosis helps greatly in fabrication. Once satisfied with the corneal position, I use the thin strip of the base plate wax to sculpt the eyelids. It is preferable to see the patient's face from all angles so that when prosthesis is fabricated, it should meet the criteria of having equal amount of elevation from the base of the orbit (Figures 23.2E to H).

I also take the pictures of the patient with the final sculpted model and download in the computer,

using the 'Adobe Photoshop 6.0' as graphical visualization makes it much easier to correct further the lids alignment, and to create a better symmetry (Figure 23.2I). Once I am done with these all steps I again go back and check the sculpted model and compare to the patient's defect, use the desire spectacle frame and cut in that fashion (Figure 23.2J).

Moulding

Making a two-piece mould is not a very complicated job, but of course making a mould is an art. Once the wax model is finished, apply the vaseline on the rear side of the prosthesis in order to get a smooth moulded surface. Mix die-stone in a ratio of 1: 1 with water. Use the vibrating unit to remove all the air bubbles and pour the mixture of die-stone and water in to a metal flask, apply some of the mixture on the back side of the model in case of any undercuts and then invest this model in the metal flask. Look very carefully as some of the dye-stone may be fast setting because before it sets you need to remove the excess material from the mould surface and check if any undercuts are there, as presence of undercuts in the

mould will finally affect the quality of prosthesis. Once the stone is set, apply the separating media (from DPI) and pour the other in the same fashion. Once the mould is set, open it very carefully and remove the wax model from the mould, clean it with the hot water and reapply the separating media (Figures 23.2K to 23.2O). Now your mould is ready for pouring the desired material.

Using the Desired Material

Attach the prosthesis to the stone moulds in its original position. Using the cynoacrylate, fix the prosthesis into its curvature so that it remains in same position as done while sculpting (Figures 23.3A to C). Till this step everything is common, and now you have to decide which type of prosthesis you are looking for.

Here I describe the making of silicon prosthesis. I mix MDX4210 with Dow corning silicon in 1:1 along with combinations of artist colors and dyes, try to match the shades of the patient skin and add more flocking so that it give much better skin appearance. I usually prefer intrinsic coloring MDX4210. As it gets set, pour into the moulds and take out all the air bubbles. Now close it from back to front, so that in case any air bubble remains, it will come on the back of the prosthesis and can be later taken care by doing the patch work (Figures 23.3D to F).

Cure the silicon at room temperature under high pressure. Once the silicon is cured, open the moulds and you have the prosthesis ready in your hand. Trim the extra margins using the 3M (Factor II) trimming wheels in a tapering fashion, so that it

Orbital Prosthesis 331

mingles well with the surrounding tissues. Sometimes one may need an extra touch up to the colors to make the appearance better (Figures 23.3G and H).

Fabrications of Ocular Prosthesis

Make the mould of same prosthesis,7 locate the Iris position and make a fresh mould, paint an iris button of the same curvature as the fellow eye and polymerize with the white base using the pressurized curing unit. Once it is cured, open the mold, create the blood vessels using the cotton rayon threads. Paint the scleral shades using dry earth pigments and cure with the clear layer of PMMA. Trim the extra portions, polish and insert into the patient orbital prosthesis, attached the eye lashes and eyebrows (Figure 23.3I).

Assemble the Prosthesis

Once you are done with fabrication of ocular prosthesis and the facial prosthesis, your ocular piece can go very easily in the cavity that has been formed in place of dummy prosthesis.

Attach the eyelashes on the upper lid and lower lids. If needed some external coloring can be done in order to look better (Figure 23.3J). Once satisfied, you have to instruct the patient regarding the use of the prosthesis.

Care of Your Prosthesis

Preparing Your Skin and Your Prosthesis

1.Repeatedly practice positioning your prosthesis without adhesive to ensure accurate placement.

332 Surgical Atlas of Orbital Diseases

Figures 23.4A and B: (A) patient with left orbital exenteration due to

Basal cell carcinoma of the left eye (B) patient with silicon glue on prosthesis in place, further cosmetic appearance improved with simple pair of glasses

2.Wash and thoroughly dry your hands and skin where your prosthesis is to be placed.

3.Clean your prosthesis with a soft, bristled toothbrush, mild soap, (e.g. Ivory liquid) and warm water.

Applying Your Prosthesis

1.If adhesive is used, it should be applied with cotton tipped swab by evenly spreading a thin layer of the adhesive along the outer edges of the backside of your prosthesis according to the manufacturer's instructions.

2.Allow the adhesive to reach its proper reapplication state depending on the type of adhesive used (e.g. dried clear for Pros-Aide).

3.Using a mirror, carefully position and press your prosthesis onto your skin to ensure good contact.

Removing Your Prosthesis

1.Remove your prosthesis from skin on a daily basis to keep your tissues healthy and to maintain hygiene. Grasp the thickest edge of your prosthesis and gently remove it very slowly so as not to tear the edges or irritate your skin.

2.If necessary, use a moist washcloth over the surface of the prosthesis to loosen adhesive from your skin.

Cleaning Your Prosthesis

1.If adhesive was used, remove it gently rolling the adhesive off the prosthesis (starting from the center to the outer edges) with your fingertips, using gauze or textured cloth. Soaking the prosthesis in a cup of warm water helps to soften adhesive and makes it easier to remove.

2.Clean the prosthesis with a soft, bristled toothbrush, mild soap (e.g. Ivory), and warm water.

3.Remove any traces of adhesive or oil by gently wiping the tissue side with a gauze or softtextured cloth moistened with rubbing alcohol. Repeat this step using a gauze or soft-textured cloth moistened with Listerine on the backside of the prosthesis.

4.If your prosthesis has an ocular component, remove and clean it with soap and water. The ocular component should NOT be cleaned with rubbing alcohol. Place a drop of mineral oil on the eye and shine it once a week. Replace the eye carefully and adjust the location by squeezing the prosthetic eyelids together.

5.If your prosthesis is retained with magnets, clips, or plastic buttons, take care to clean around each fixture with a soft, bristled brush, soap and water.

Cleaning Your Skin

1.Wash your face with soap and water after removing the prosthesis and remove any residue of adhesive from the skin. Avoid the use of harsh solvents such as benzene or xylene.

2.Apply a moisturizing lotion on nightly basis to restore natural body oils.

3.Report any areas of inflammation or irritation to the office or clinic.

Color Changes

1.Avoid smoking, as it will stain prosthesis yellow.

2.Avoid prolonged exposure to sunlight, which can cause color dissolution and weakening of the prosthetic material.

3.Avoid the use of strong solvents, such as benzene and xylene, which can cause dissolution and weakening of the prosthetic material.

Storing the Prosthesis

1.Store the prosthesis in a dry, inconspicuous but safe place (for example, a bedside table drawer). Keep it out of the reach of children and animals.

2.If you have an orbital prosthesis, store it in an upright position.