Because of unpredictable corneal changes, evisceration and implantation of a silicone prosthesis does not always lead to a satisfying cosmetic result. This paper describes the use of an intraocular silicone prosthesis in combination with an extraocular glass prosthesis and shows a followup of two and a half years in a nonexperimental study. An intraocular silicone prosthesis was implanted after evisceration of the left eye in a five-month-old Bernese mountain dog. A glass prosthesis was fitted four weeks after evisceration. Two and a half years after the operation, the dog is in good health and free of medication. No short-term or long-term complications were seen. The owners do not have trouble with handling the glass prosthesis. The combination of both prostheses shows a perfect solution to retrieve a normal looking and moving eye after evisceration.
In both human and veterinary ophthalmology several surgical options are described to treat an end-stage glaucomatous eye that does not respond to medical therapy.
The easiest and fastest procedure is enucleation of the eye. Evisceration and implantation of a silicone prosthesis is an alternative which gives a better cosmetic result [
A disadvantage of evisceration and silicone implantation in dogs is the neovascularization of the cornea immediately after evisceration. One to two months after the operation, the cornea will be completely vascularized [
Overview of selected options to restore anatomical structure after exenteration, enucleation, or evisceration [
Surgical procedure | Prosthesis material | Site of implantation | Coupling system | Second prosthesis | Eyelid movement | Globe movement |
---|---|---|---|---|---|---|
Exenteration | Silicone | Intraorbital | No | — | ||
Hydroxyapetite | ||||||
| ||||||
Enucleation | Silicone | Intraorbital | No | — | ||
Acrylic | + | — | ||||
Glass | + | — | ||||
Hydroxyapetite | Intraorbital | No | — | |||
Acrylic | + | — | ||||
Glass | + | — | ||||
Yes | Acrylic | + | ++ | |||
| ||||||
Evisceration | Silicone | Intraocular | No | — | + | ++++ |
Bandage lens | + | ++++ | ||||
Acrylic | + | +++ | ||||
Glass | + | +++ | ||||
Hydroxyapetite | Intraocular | No | — | + | ++++ | |
Bandage lens | + | ++++ | ||||
Acrylic | + | +++ | ||||
Glass | + | +++ | ||||
Yes | Acrylic | + | ++++ |
Anatomical position of different prostheses. 1: intraocular prosthesis introduced within the empty tunica fibrosa after evisceration. 2: second extraocular prosthesis or “artificial eye,” lying between the conjunctiva (third eyelid in animals) and eyelids. Brown: eyelid skin, pink: conjunctiva, and yellow: tunica fibrosa.
Transscleral cyclophotocoagulation with diode laser or cryotherapy in combination with an Ahmed gonioimplantation in dogs with primary glaucoma has a success rate of approximately 76%, and most of the patients still need long-term medication [
Ciliary body ablation by intravitreal gentamicin injection for the treatment of end-stage glaucoma is thought to correlate with the development of malignant intraocular tumours [
This paper shows a followup of two and a half years of a dog with an intraocular silicone prosthesis combined with an extraocular glass prosthesis after evisceration.
A three-month-old, male Bernese mountain dog was presented to a private veterinarian after a cat claw injury in his left eye. Ophthalmic examination, including fluorescein staining, Seidel Test, slit lamp biomicroscopy and B-mode ultrasound, led to the diagnosis of corneal perforation without injury of the lens. Under general anesthesia, the corneal wound was cleaned and afterwards closed with simple interrupted sutures (Vicryl 8/0, Ethicon, Johnson & Johnson, Norderstedt, Germany). An additional nictitating membrane flap was performed to protect the corneal wound. Postoperative treatment included topical treatment with neomycin, gramicidin, and polymyxin B eye drops TID (Polyspectran, Alcon, Freiburg, Germany) and atropine eye drops SID (Atropine-POS 1%, Ursapharm, Saarbrücken, Germany) and systemic treatment with amoxycillin-clavulanic acid 12.5 mg/kg BID (Clavaseptin, Vétoquinol, Ravensburg, Germany) for two weeks and carprofen 4 mg/kg SID (Rimadyl, Pfizer, Karlsruhe, Germany) for six weeks.
After six weeks, the eye became blind and the dog was referred. Ophthalmic examination of the blind eye revealed secondary glaucoma with an intraocular pressure of 29 mmHg measured by rebound tonometry (TonoVet, Acrivet-Veterinary Division, Hennigsdorf, Germany). Topical treatment including carbonic anhydrase-inhibitor and
Four-and-a-half-month-old Bernese mountain dog with end-stage, glaucomatous left eye seven weeks after cat claw injury.
The dog underwent general anesthesia. The left eye was cleaned in a routine manner for eye surgery. A Barraquer eyelid speculum was placed to open the eyelids. The conjunctiva was prepared for a 360° flap by a complete perilimbal incision with a Stevenson’s scissor. The cornea was excised by a 360° scleral incision with a Beaver blade nr. 65 and Stevenson’s scissor 1 mm behind the limbus (Figure
Perilimbal perforating scleral incision as preparation for implantation of intraocular silicone prosthesis.
The content of the globe was removed with a lens loop, leaving an empty scleral shell. An 18 mm silicone prosthesis (Acrivet-Veterinary Division, Hennigsdorf, Germany) (size of the healthy eye, measured as the distance between the posterior surface of the cornea and the anterior surface of the sclerawith B-mode ultrasound) was placed into the scleral shell with a Carter sphere introducer (Acrivet-Veterinary Division, Hennigsdorf, Germany). The sclera was closed above the prosthesis with interrupted horizontal mattress sutures (Vicryl 6/0, Ethicon, Johnson & Johnson, Norderstedt, Germany) (Figure
Closure of the sclera above the intraocular silicone prosthesis.
The 360° limbal-based conjunctival flap was closed above the sclera in a simple continuous pattern by the use of the Vicryl 6/0 (Figure
Closure of the conjunctiva above the sclera.
A temporary tarsorrhaphy with the use of a monofilament suture material (Dafilon 4/0, Braun Aesculap, Tuttlingen, Germany) was performed to protect the empty fornix (Figure
Temporary tarsorrhaphy to protect the empty fornix.
The sclera and conjunctiva healed within two weeks, and after which the tarsorrhaphy was released.
Three weeks after the surgery, an extraocular prosthesis of glass was prepared by an ocularist (Figure
Artificial glass eye (extraocular prosthesis).
The prosthesis was placed into the fornix, above the conjunctiva, sclera, and intraocular prosthesis (Figure
Postoperative treatment included systemic treatment with amoxycillin-clavulanic acid 12.5 mg/kg BID (Clavaseptin, Vétoquinol, Ravensburg, Germany) and metamizol 20 mg/kg TID (Novaminsulfon, Ratiopharm, Ulm, Germany) for five days. No topical treatment was applied. The wound was examined one day, one week, and two weeks after surgery. No further systemic or local medication was indicated.
The glass prosthesis has to be taken out every evening. The prosthesis is placed overnight in a generally available lens cleaner (for example Boston Simplus all in one, Bausch & Lomb, Berlin, Germany). In the morning, the conjunctival sack is flushed with a generally available eye cleaner (e.g., Albrecht, Aulendorf, Germany), and the prosthesis is placed back into the fornix.
Pictures were taken two months, one and a half year, and two and a half years after surgery (Figures
Six-and-a-half-month-old Bernese mountain dog with intraocular and extraocular prosthesis two months after surgery.
Two-year-old Bernese mountain dog one and a half year after surgery.
Three-year-old Bernese mountain dog two and a half years after surgery.
The extraocular prosthesis was replaced by the same ocularist for a new prosthesis after one year and after two and a half years. By experience, the ocularist was able to fit the last prosthesis in such a manner that less white of the prosthesis is seen. The only (long-term) complication is a little intermittent serous secretion. There is no history of a bacterial infection or insufficient tear production. Schirmer’s tear test readings were always above 15 mm per minute. The dog is happy, does not need any medication and behaves and looks like a dog with two normal eyes. The dog does not show any discomfort with the intraocular and extraocular prosthesis.
The owners are very satisfied with the cosmetic result and do not feel inconvenienced by the handling of the extraocular prosthesis. Given the same circumstances, they would make the same decision again.
In human ophthalmology, the main advantage of evisceration over enucleation is that evisceration is described as the easier procedure with less orbital manipulation, hemorrhage, and reduced postoperative swelling, pain, and associated trauma [
Kennedy [
In this case the evisceration was combined with a full-thickness keratectomy, because the eye was so buphthalmic. Additionally, in human ophthalmology excision of the cornea is described for those patients who may still have corneal sensation or corneal pain. The removal of the cornea allows the sclera edges to be united, which provides a secure wound closure [
Due to the preoperative buphthalmic eye, the silicone implant, which was the size of the other normal eye, could be introduced, and the sclera wound could be opposed without tension releasing incisions or posterior radial sclerotomies, which may be used in human ophthalmology [
In dogs, implantation of silicone prosthesis after evisceration has been used already for many years [
The first extraocular prostheses for humans were made of glass, mainly produced in Germany. During World War II, an increased demand for glass eyes and limited export from Germany led to the development of acrylic prostheses [
In an eviscerated eye without keratectomy in which a fibrotic cornea develops a tinted bandage lens can be tried to camouflage the white appearance. Care must be taken with those eyes that develop a lower tear production.
The motility of an intraocular prosthesis together with the extraocular prosthesis can be further increased by addressing a motility coupling system, like a peg, between the two prostheses [
Different studies show that 10% of the eviscerated canine eyes developed a keratoconjunctivitis sicca (KCS) [
This paper shows that the combination of both prostheses offers a good treatment option with very good cosmetic results, with no discomfort for the dog and no need for additional medication.