Ocular prosthesis: restoring the volume and symmetry of the face

Losing an eye — to a tumour, severe trauma, or a blind and painful eye with no prospect of recovery — is a difficult situation both functionally and personally. Prosthetic rehabilitation does not give sight back, but it can restore the volume, the symmetry and the appearance of the face.

It is a part of oculoplastics little known to patients, and it deserves to be explained properly.

Two separate pieces

There is a frequent confusion here worth clearing up from the start. Rehabilitation has two components:

The orbital implant. This is a sphere placed inside the socket during surgery, to replace the lost volume. It sits inside, is not visible and is not removed. It is sutured to the eye muscles, which are what will give it movement.

The ocular prosthesis. This is the visible piece, custom-made by an ocularist, shaped like a thick shell rather than a sphere. It sits in front, over the conjunctiva and behind the eyelids. It is what reproduces the iris, the pupil and the vessels of the sclera.

The quality of the final result depends on both: a good implant without a good prosthesis does not look right, and an excellent prosthesis over a socket with insufficient volume does not either.

The possible operations

Evisceration. The internal contents of the globe are removed, keeping the sclera and, usually, the muscles attached to it. It generally gives good motility.

Enucleation. The whole globe is removed. It is indicated when there is an intraocular tumour, because it allows histopathological study of the specimen and secures the margins.

Exenteration. A major procedure, reserved for tumours with extensive orbital invasion, in which the contents of the orbit are removed. Rehabilitation in these cases is different and more complex.

The choice is not a preference: it depends on the cause. In tumour disease, enucleation is usually the correct indication.

How the process works

Surgery. The eye or its contents are removed and the orbital implant is placed, suturing the muscles to preserve movement.

Temporary conformer. During the first weeks a clear piece is fitted that keeps the shape of the conjunctival fornices while the swelling settles. Without it, the fornices can contract and there will then be no space to house the prosthesis.

Fitting the prosthesis. After a few weeks, the ocularist takes a mould of the socket and makes the prosthesis to measure. It is hand-painted to reproduce the colour of the iris, the pattern of the sclera and the vessels of the other eye. It is craft work, and its quality shows a great deal in the result.

Follow-up. Periodic checks of the socket and polishing of the prosthesis.

What result is realistic

It is worth being precise, because poorly calibrated expectations create unnecessary frustration.

Looking straight ahead, in normal conversation and at social distance, a well-fitted prosthesis over a well-rehabilitated socket is very hard to distinguish. Most people around the patient do not identify it.

Movement, on the other hand, is not identical to that of a natural eye. In extremes of gaze the difference becomes more evident, and the prosthesis does not dilate or constrict its pupil.

That is the honest framing: a result that works very well in everyday life, without being a perfect replica.

Lifelong care

• Periodic cleaning as instructed, without excessive handling.
• Professional polishing of the prosthesis by the ocularist on a regular basis: the surface becomes microscopically rough over time and that irritates the conjunctiva and increases discharge.
• Lubrication of the socket if there is dryness.
• Checks on the state of the fornices and the eyelids.
• Seeking advice in the event of copious discharge, persistent redness, new discomfort, or if the prosthesis begins to move or fall out.

In children there is also a structural reason

In childhood, rehabilitation serves a purpose that goes beyond appearance: the presence of adequate volume within the orbit stimulates bone growth on that side of the face.

An orbit that grows without volume develops less than the other side, and that facial asymmetry is afterwards far harder to correct than the absence of the eye itself.

That is why in paediatric patients follow-up is more frequent and the prostheses are replaced as the child grows.

A final note

The conversation about losing an eye is one of the hardest in clinic. It is reasonable that the patient and their family need time, clear information and, in many cases, psychological support.

Explaining properly what can be recovered — and what cannot — is part of the treatment, not an extra.