Comparative Motility of Alloplastic Orbital Implants

Fayoum University Hospital

Status: Unknown

Conditions: Anophthalmos; Acquired; Evisceration; Traumatic, Eye

Treatments: Procedure: Evisceration with orbital implantation

Study type: Interventional

Funder types: Other

Identifiers

NCT04464109

R116/2020

Details and patient eligibility

About

This study will evaluate the effect of posterior placement of orbital implants on their motility compared to intrascleral placement after evisceration .

Full description

Evisceration allows removal of the intraocular contents while preserving the sclera and normal extraocular muscle attachments. It is more advantageous than enucleation in patients in whom intraocular tumor is rules out.

Maximizing orbital volume and restoration of movement are important aspects of a successful surgical outcome.

Standard evisceration techniques do not allow placement of an implant larger than 13-16 mm which don't adequately replace the volume leading to postevisceration socket syndrome. Therefore, various techniques have been described to expand the scleral cavity and allow placement of a large implant including anterior sclerotomies, posterior sclerotomies, and disinsertion of optic nerve.

Implant exposure is a terrible complication of evisceration with reported rates as high as 67%. Exposure of the implant can lead to infection, which usually mandates removal of the implant. Trying to minimize this risk, physicians intentionally place the implants posterior to the normal position of the globe. Some authors described placement of the implant posterior to posterior sclera which totally eliminated the risk of exposure.

However, this deep seating of the implant may have deleterious effects on its motility. It can decrease implant-prosthesis interaction. In addition, retro-scleral placement of the implant moves it posterior to the pulleys that serve as the functional origins of rectus muscles. This relationship would be expected to alter the pulling directions of the rectus muscles after evisceration hindering effective implant motility.

In this trial the investigators will try to study the effect of posterior placement of the implants on its motility after evisceration.

Enrollment: 30 estimated patients

Sex: All

Ages: 18 to 50 years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• Patients who are candidates for evisceration

Exclusion criteria

• Inability to provide independent, informed consent
• Significant preoperative motility abnormalities

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Double Blind

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30 participants in 2 patient groups

Retro-scleral placement of the implant

Active Comparator group

Description:

Surgical steps; 1. Two anterior scleral relaxing incisions 2. A 360° scleral incision around the optic nerve to disinsert it 3. Two posterior scleral relaxing incisions 4. The implant is inserted posterior to posterior scleral edges 5. The posterior sclera is closed then the anterior sclera is overlapped and closed. 6. The implant is completely seated in the intraconal space

Treatment:

Procedure: Evisceration with orbital implantation

Intrascleral placement of the implant

Active Comparator group

Description:

Anterior and posterior sclerotomies with the implant partly in the scleral shell and partly in the intraconal space. 1. Anterior relaxing sclerotomies not reaching the optic nerve 2. A 360° scleral incision around the optic nerve. 3. The anterior sclera flaps are overlapped and closed 4. Part of the implant remains in the scleral shell, while the remaining part is sitting in the intraconal space.

Treatment:

Procedure: Evisceration with orbital implantation