Loss of an eye deeply affects the individual’s self- esteem particularly in those who have lived the major part of their life seeing the world with both eyes and worse in those who are born with this disability. In addition to this there is loss of binocular vision and depth perception which in turn affects one’s social and professional life. With newer innovations in artificial eye making, it is possible to cosmetically rehabilitate with a Custom-made ocular prosthesis (artificial eye).
An ocular prosthesis is a non-optical device designed to improve the cosmesis of an individual with anophthalmic socket or disfigured eye. An Ocularist is an expert who designs the prosthesis which is custom-made for a given individual in such a way that it matches the living eye in every possible aspect.
There are certain pre-requisites for fitting of a custom-made artificial eye,
- The socket should be of good volume & contour (Surface area) for fitting an artificial custom made eye. It requires evisceration/enucleation/exenteration along with an implant surgery or a graft surgery (fat graft/mucous membrane graft) for optimal outcome.
- A quiet & healthy socket
- Patient having realistic expectations
- Close co-ordination between the referring ophthalmologist, Oculoplastic surgeon & Ocularist for appropriate management.
Enucleation & Evisceration:
Enucleation refers to removal of the entire eyeball with ocular coats (sclera & choroid), leaving behind the extraocular muscles (EOM) and conjunctiva. The indications for enucleation are intraocular tumours like retinoblastoma, choroidal melanoma, and painful blind eye as post chronic glaucoma, trauma with an unsalvageable eye or a phthisical eye
Evisceration is removal of the contents of the eye with preservation of the scleral cup along with EOM & conjunctiva. The indications for evisceration are panophthalmitis or extraocular spread of infection or a staphylomatous eye, where the walls of the eyeball are thinned out and protruding. Evisceration is the preferred procedure with definite advantages over enucleation like less operating time, better eye movements, less appearance of a sunken eye & less disruption of normal anatomy.
Exenteration refers to removal of the eyeball and the contents of the orbit and surrounding tissues.
The aim of all these surgeries is to get an ideal socket where there is adequate space between the upper and lower lids with adequate volume due to the implant so that the prosthesis can snugly fit and match the other eye.
FIGURE 1
The above picture shows
Fig a) Fundus image of choroidal melanoma
Fig b) penetrating trauma
Fig c) retinoblastoma
Fig d) painful blind eye
Fig e) anterior staphyloma
Fig f) Phthisical eye
Implants:
Whenever there is loss of an eye, the volume deficit created should be replaced maximally by an orbital implant and minimally by the artificial eye or prosthesis. There are different types of implants available. They can be inert – like glass, silicone or Biointegrated like porous polyethylene or hydroxyapatite.
Integrated implants were previously in vogue and there was a pegging system by which the implant was attached to the prosthesis. However there is no real advantage of Biointegrated implants over inert implants unless pegging is performed (figure below)
FIGURE 2
Fig a) Right eye post evisceration with a conformer
Fig b) Enucleated socket.
Fig c) Eviscerated socket
Fig d) Socket without implant post enucleation.
Fig e) porous implant
Fig f) Acrylic implant
Types of prosthetic devices:
- Prosthetic contact lenses – this is used in patients with corneal scar and minimal volume loss. This needs a smooth surface for optimal fit.
- Prosthetic eye or shell – this is fitted in patients with a shrunken eye or those with a socket without an eyeball. This is made for the patient on an individual basis. These can be custom made or stock eyes. The stock eyes are also available in the market but invariably lead to allergic reactions and lid and socket damage.
- Orbital prosthesis or facial prosthesis – this is fit in patients with severe injury or post orbital surgery like exenteration. This is made based on the needs of the patient.
- Prosthetic contact lenses – this is used in patients with corneal scar and minimal volume loss. This needs a smooth surface for optimal fit.
- Prosthetic eye or shell – this is fitted in patients with a shrunken eye or those with a socket without an eyeball. This is made for the patient on an individual basis. These can be custom made or stock eyes. The stock eyes are also available in the market but invariably lead to allergic reactions and lid and socket damage.
- Orbital prosthesis or facial prosthesis – this is fit in patients with severe injury or post orbital surgery like exenteration. This is made based on the needs of the patient.
Custom-made Ocular Prosthesis:
The technique of fabrication of a custom ocular prosthesis takes 1-2 days. After obtaining a socket impression under topical anesthesia (GA for kids), a wax prototype is replicated to obtain an optimal size & fit. The patient’s iris is painted in reference to his normal fellow eye on a corneal button/iris disc. A superior medical grade, PMMA material used to make the prosthesis. The patient’s eye colour is matched using appropriate colour matching techniques for a true life-like appearance. The final prosthesis is polished to high gloss which snugly fits in the socket and gives good real time motility and normal appearance to the patient.
Indications of ocular prosthesis:
Congenital conditions:
- Microphthalmos (small eye)
- Anopthalmia (absence of eyeball)
- Advanced Bupthalmos (large eye with no vision)
Acquired conditions:
- Phthisis bulbi (shrunken eye) post trauma
- Painful Blind eye (ciliary staphyloma, end stage glaucoma)
- Atrophic globe
- Post failed retinal surgery
- Intraocular malignancies
- Chemical injuries
- Disfigured & opaque cornea (dermoids, dense leucoma)
- Contracted sockets
Advantages of Custom-made Ocular Prosthesis over Stock eyes (ready-made shells):
| Custom ocular prosthesis | Stock eye |
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By,
Ms. Madhullata Umesh, B.Optom,
Optometry Fellow, LVPEI, Ocularistry Fellow,
IPEC, Hyderabad.