Prosthetic Eye Types

Context: Why a Prosthesis is Needed

1. Orbital implant — replaces lost orbital volume (sits deep in the socket, not visible)
2. Ocular prosthesis — the painted shell placed over the implant that faces the outside world

1. Conformer (Temporary Device)

• Placed immediately after enucleation/evisceration to maintain the conjunctival fornices
• Made of silicone or acrylic (PMMA)
• Remains in place until a fitted prosthesis is ready (typically 6–8 weeks postoperatively)
• Not cosmetically painted — purely a structural spacer

2. Stock (Pre-fabricated) Prosthetic Eye

• Mass-produced in standard sizes and iris colours
• Used as a temporary artificial eye while a custom prosthesis is being manufactured
• Less cosmetically accurate but immediately available

3. Custom Acrylic (PMMA) Prosthetic Eye

• Polymethylmethacrylate (PMMA) — the dominant material for modern ocular prostheses
• Individually cast from an impression of the patient's socket
• Painted by an ocularist to match the iris colour, limbal ring, and conjunctival vasculature of the fellow eye
• Lightweight, durable, polishable
• The most widely used type in clinical practice

Custom PMMA ocular prostheses hand-painted to match different iris colours — Kanski's Clinical Ophthalmology

4. Glass Eye (Historical)

• Traditionally made from cryolite glass (a sodium aluminium fluoride compound)
• Lightweight and with a natural surface sheen
• Fragile, prone to breakage and surface degradation
• Largely replaced by acrylic in most countries, though still manufactured by specialist glassblowers (notably in Germany and the UK)

5. Orbital Implants (Supporting the Prosthesis)

Extrusion is a risk with all implant types. Deep, well-vascularised placement is more important than material choice. — Kanski's Clinical Ophthalmology, p. 168–169

6. Orbital Prosthesis (for Exenterated Sockets)

• A full orbital prosthesis is fabricated from silicone, incorporating:
  • A PMMA ocular component (painted to match the contralateral eye)
  • Sculpted eyelids and surrounding periorbital tissue
  • Eyelashes (and sometimes an eyebrow)
• May be retained by adhesive or attached to spectacles frames
• Orientation of the ocular component is calibrated to match the gaze direction of the remaining eye using light reflection and rulers

Complications Common to All Prosthetic Eyes

• Giant papillary conjunctivitis (GPC) — from chronic mechanical irritation of the tarsal conjunctiva
• Post-enucleation socket syndrome (PESS) — upper lid ptosis, superior sulcus hollowing, enophthalmos, sagging lower lid; results from orbital volume deficit, especially without an implant
• Implant extrusion — most feared implant complication