Anophthalmos
Exposed Orbital Implant
 |
The Photograph on the left is an exposed orbital implant. The implant, once exposed, is at risk for extrusion. If the exposure is limited it may be repaired surgically. Otherwise, it my need to be removed, and a dermal fat graft procedure performed |
 |
 |
-
Loss of volume
-
Structural changes
-
Fat atrophy
-
Retraction or changes in extraocular muscles
-
Loss of support of the levator complex
Normal Volumes of the Orbit
-
Adult orbital volume ranges from 24 to 30 ml
-
Female orbital volume is approximately 2 mm less than male adults
-
Each orbit contains approximately 10 ml of fat; extraocular muscles account for 5 ml of volume and the normal eyeball accounts for approximately 7 ml.
Following enucleation there is a decrease in volume as well as changes in structure which give rise to what has been termed “post-enucleation socket syndrome.”
-
This involves enophthalmos, a deep upper eyelid sulcus, lower eyelid laxity with shallow fornix with possibly Ptosis or lid retraction.
-
When an eye is removed, recall there is a 7 ml volume loss; however, the most commonly used 18 ml sphere replaces a volume of approximately 3 mm while a 16 mm sphere replaces a volume of 2 ml. A 20 mm sphere provides 4.1 ml of volume.
-
The situation is made worse by orbital fat atrophy of up to 3 ml.
-
It is unclear whether fat atrophy recurs as a result of reduction of blood supply or due to mechanical manipulation during surgical enucleation.
- Bony orbital volumes are also noted to be smaller in patients who have had long-standing enophthalmia.
Please Note: The POREX SURGICAL service mark is owned by or used under the license and authority of Porex Corporation. MEDPOR is a registered trademark of Porex Surgical, Inc. COI is trademark of Porex Surgical, Inc. Descriptions of the MEDPOR Biomaterial, Orbital Spheres, COI and MEDPOR MCP Motility Coupling Post are protected under copyright and are used with permission from POREX SURGICAL
 |
|
|
|
|
before operation | after operation | |
|
|||
