Ocular Prosthetics Flashcards

Which complication is most associated with a hydroxyapatite orbital implant in the years following placement?

Answer: Implant exposure or extrusion through the conjunctiva

Implant exposure — where the conjunctiva breaks down and the implant becomes visible — is the most clinically significant long-term complication of hydroxyapatite implants.

A patient reports that their prosthesis 'falls out' when looking downward. Which prosthetic modification would most likely correct this?

Answer: Adding material to the superior posterior surface to improve upper fornix retention

Adding acrylic to the superior posterior surface increases contact with the upper fornix, improving retention and preventing inferior displacement on downgaze.

What is the significance of matching the 'limbal ring' when painting a custom ocular prosthesis?

Answer: It creates a realistic transition between the iris and sclera, adding to the natural appearance of the eye

Accurately replicating the limbal ring — the darker circle at the iris-sclera junction — is essential for achieving a natural, lifelike appearance of the prosthetic eye.

When fabricating an impression of an anophthalmic socket, which material property is most important to prevent discomfort or socket injury?

Answer: Low exothermic heat generation and adequate flexibility for removal

Impression materials for socket impressions must generate minimal heat during setting and be flexible enough to remove without traumatizing the delicate conjunctival tissue.

A patient who underwent radiation therapy to the orbit presents with a severely contracted socket. What tissue change best explains the contraction?

Answer: Fibrosis and scarring of conjunctival and orbital tissues leading to fornix obliteration

Radiation causes progressive fibrosis and scarring of soft tissues, resulting in contracted fornices and reduced socket volume that challenges prosthetic fitting.

What is the role of the 'pupil' painted on an ocular prosthesis?

Answer: It creates the illusion of a real pupil and contributes to realistic appearance and directional gaze impression

The painted pupil is a critical cosmetic element that creates the illusion of a natural pupil and influences the perceived gaze direction of the prosthetic eye.

In ocular prosthetics, what term describes the shell-type prosthesis worn over a remaining but disfigured eye (phthisis bulbi)?

Answer: Scleral shell or cosmetic shell

A scleral shell (cosmetic shell) is a thin, hollow prosthesis worn over a phthisical or disfigured eye to restore normal appearance without enucleation.