Osmed

Two innovative Osmed™ configurations are available: Hemispheres for expansion of the socket and palpebral fissure. Spheres for expansion of the bony tissues of the deep orbit.

The Osmotic Tissue Expander consists of a Methylmethacrylate and N-Vinylpyrrolidone copolymer similar to what is used to manufacture soft contact lenses. This innovative biomaterial has been chemically modified so that expands up to 12 times in volume when exposed to liquid.

The tissue expansion is carried out passively with a consistent rate of pressure of approximately 20-30mmHg as the device absorbs fluid from the surrounding tissue space. The rate and time is dependent of the available moisture and the counter pressure of the tissue space.

There are two available configurations: hemispheres for the soft tissues of the socket and palpebral fissure and spheres for the bony tissues of the deep orbit. The soft tissue of the palpebral fissure begins expanding immediately producing notable results in approximately one week. Expansion of the bony orbit may take 6 months or more.

The device configurations are used as a complementary system to maximize the potential to achieve uniform cosmetic symmetry.

Osmed™ Hemisphere Socket Expander

• 0.9 ml configuration before and after hydration.
• Suture holes facilitate implant placement with or without tarsorraphy sutures.
• Available in five (5) sizes: 0.4, 0.9, 1.5, 2.0, 2.7 ml.
• Untreated anophthalmic socket prior to expansion therapy.
• Sterile expander is inserted into the superficial socket dry. Contact with moisture will begin the expansion process.
• An optional U-shaped tarsorraphy may be used to help secure the socket expander in place.
• Expander position in situ. The expander volume has increased 10 times by absorbing water from the surrounding tissue space.
• Significant increase in both fissure length and socket volume to accommodate a larger prosthesis.

Osmed™ Spherical Tissue Orbit Expander

• 4.0 ml configuration before and after hydration.
• Designed to expand the tissue of the deep bony orbit.
• Available in four (4) sizes: 2.0, 3.0, 4.0, 5.0 ml.

Bilateral Anophthalmic Patient (Pre-operative)

• Pre-operative photo shows narrow eyelids covering small sockets.

Bilateral Anophthalmic Patient (During treatment)

• Same patient following placement of hydrogel tissue expanders.
• Tissue expanders mimic the appearance of eyeballs.

Description

Osmotic tissue expanders are co-polymer based devices intended to expand physiological tissue space. The material is a Methylmethacrylate and N-Vinylpyrrolidone polymer. The expansion is a result of osmotic swelling due to the absorption of fluid from the surrounding tissues.

Instructions for Use

Both the orbit expanders(spheres) and socket expanders (hemispheres) are packaged sterile and non-pyrogenic for SINGLE USE ONLY. The implants are double wrapped in a chevron type peel pouch and should remain secured in this pouch until the implant site has been prepared to accept the device.

Indications

Osmotic tissue expanders are indicated for the facilitation of normal growth of orbital soft tissues and bone to achieve proximate facial symmetry in congenital anophthalmos and microphthalmos.

Contraindications

The use of the orbit expander is contraindicated in the presence of a microphthalmic eye with useful vision.

Precautions

The expander devices operate by the osmotic absorption of fluid. The devices must remain separate from body fluids and irrigating solutions prior to use. Care must be taken when explanting the device because the material becomes soft and more fragile when fully hydrated. Rough or excessive handling may result in fragmentation of the hydrogel material following expansion. Any fragments that may have separated from the device during explanation should be removed.

Warnings

The clinical effect of X-ray on the implanted device has not been determined. MRI is recommended.

Adverse Events

The clinical data on these devices consists of two published papers and an ongoing clinical study. Complications reported in the literature for the orbit expanders consist of infection, insufficient closure and the use of a sphere that is too large. The complication reported in the literature for the socket expander is the spontaneous expulsion due to insufficient closure.

Orbit Expansion

The implant site for the sphere should be prepared by spreading the soft tissue with surgical scissors to establish a location deep within the orbit. A two-layer closure with interrupted absorbable sutures will help to minimize the potential for extrusion during the expansion phase. A temporal incision may be used if the conditions permit the ability to work the implant around the orbital rim and back into the deep orbit.

The implants are sized for progressive use. The procedure can be repeated with consecutively larger sized spheres based on the response of the tissue as determined by the physician. For example, the 2ml sphere may be removed and replaced with a 3ml or 4ml sphere as needed. Final closure should consist of a temporary tarsorraphy with non-absorbing suture material and use of a conformer as needed. Use of perioperative antibiotics is recommended.

Socket Expansion

The hemispherical expander is intended to expand the lid fissure. The expander should be placed with the convex side facing anteriorly. The device should be secured directly to connective tissue. The suture placed through the fixation hole must be tied loosely in order to compensate for expansion of the device. When an appropriate volume is obtained, the final expander should be replaced with a permanent orbital implant and prosthetic shell.

Orbit Expanders - The sphere configuration is used for orbit expansion.

Socket Expanders - The hemisphere configuration is used for expansion of the soft tissues of the eyelids.

	Start Vol	Start Diam	End Vol	End Diam1
Hemisphere	0.13±0.02ml	8.0±0.1 mm	0.9±0.1ml	14.0±0.5mm
2ml Sphere	0.27±0.03ml	8.0±0.2 mm	2.0±0.2ml	15.5±0.5mm
3ml Sphere	0.27±0.03ml	8.0±0.2 mm	3.0±0.2ml	18.0±0.5mm
4ml Sphere	0.43±0.03ml	9.0±0.2 mm	4.0±0.2ml	19.7±0.5mm

1 The in-vivo swelling is subject to patient biochemistry and location specific variables. The final labeled volume and diameter have been established in a 0.9% NaCl control solution. The physiological hydrostasis of the tissue environment is less efficient and therefore will not achieve the final labeled volume.

Clinical Results

The published clinical data to date reports on the implantation of a total of twelve socket expanders and two orbit expanders. The following table represents the before and after palpebral fissure expansion measured in millimeters for the patients receiving socket expanders.

Patient	Age Mos.	Expansion Days	Before OD	After OD	Before OS	After OS
1	6	30	8	20	9	20
2	11	24			9	24
3	5	24	10	22
4	7	30	8	20	9	20
5	11	60	10	17	21	23
6	4	60	10	15	18	20
7	3	60	9	12	19	19

Two cases received the orbit expanders in addition to the socket expanders. There was no reported increase in palpebral fissure with the incremental use of the orbit expander in these cases. The following table demonstrates the time frame and final volumes of the orbit expanders. The volume was determined by CT-scan 150 and 40 days after implantation.

Patient	Expansion Time	Volume Before	Volume at Scan
2 OS	150 days	0.42 ml	4.5 ml
3 OD	40 days	0.44 ml	4.0 ml

Technical Data: Osmed™ Hydrogel Orbit Expanders

The spherical configuration is used to expand the tissue of the deep bony orbit. This sphere represents the shape of the natural globe and is ideally suited to expand the deep orbital space.

The spheres are also available in three sizes to provide multiple options for each individual case and to stage the expansion program if necessary.

Orbit Expansion Techniques

The ability to expand the socket and the palpebral fissure to the desired size and appearance may be limited by the bony tissues of the orbit. In this case a sphere is used.

The insertion technique consists of placing expanding spheres deep within the orbital tissues. It may be inserted in the same fashion as a standard orbital implant. Care must be taken to completely close the insertion incision. The incision should be closed with a secure technique to compensate for the forces of expansion.

In addition, a temporal incision may also be used. A temporal incision in made to enable the subcutaneous insertion of a dry sphere. A passage for the expander is prepared with blunt dissection to the deep orbit. The dry sphere may then be worked around the orbital rim and back into the orbit. The advantage of this technique is the incision site is isolated from the area of tissue expansion.

Exchange of Orbit Expander

Exchanging the orbit expander for a larger size may be necessary as the child grows.

The procedure is similar to the initial implantation. The expander may be aspirated through a small incision in the dorsal conjunctiva. Osmotic tissue expanders consist of a soft gel when fully hydrated and can be broken into small particles; these particles may be removed with sterile saline solution irrigation.

The socket will have a hollow capsular sack. It is important to remove all remaining particles and make relaxing incisions in this capsular sack to accommodate the increase in volume with the subsequently larger expander. The incision in the dorsal conjunctiva may be enlarged to accommodate the subsequently larger expander.

Technical Data: Osmed™ Hydrogel Socket Expanders

The hemispheres are used to begin the expansion of the soft tissues of the superficial socket. The hemispheres are equipped with suture holes to facilitate placement with or without tarsorraphy sutures.

The Hemispheres are available in three sizes to accommodate variation in each individual case and to carryout the expansion process in multiple stages if necessary.

Surgical Techniques

Every case is different and therefore the application of variations in surgical techniques may be required and must account for previous treatment, etc.

In general, the tissue expansion protocol will normally begin with the insertion of a hemispherical expansion device to expand the socket and palpebral fissure.

Socket Expansion

A dry hemisphere of the appropriate size is fixated into position within the lid fissure with the convex side of the implant facing anteriorly. Once inserted, the device will slowly expand the tissue by absorbing water from the tissue space.

The material becomes increasingly softer and more fragile as it absorbs water. Therefore the sutures are tied loosely to provide play for expansion.

For example, the suture holes on the medium sized hemisphere are 3mm apart when dry and are 10mm apart when fully expanded. If a single suture is used, the soft tissue fixation points should be separated to compensate for expansion. A non absorbable such as a 6-0 prolene is recommended.

An alternative suture technique is to use two interrupted sutures fixated to the superior and inferior periosteum of the orbital rim. This allows the device to expand outward in the direction of the suture loops.

Tarsorraphy

One or two U-shaped non-absorbable tarsorraphy sutures may be used to help retain the expander within the socket. The temporary tarsorraphy sutures may be attached to silicone pearls or silicone tubes to reduce the load on the sutures.

Eye drops may be used if the socket is too dry to expand the material. This is intended to expand the soft external tissues achieve more normal proportions for the eyelid margin.

The relevance of the reimbursement codes depends on indications of use and geographic region. Please use this hotline to determine what the guidelines are for your area. IOP Reimbursement Hotline 1.888.700.9005

Coming Soon

Surgicial Guides

Not Available

White Papers

Not Available

Case Studies

Not Available