A retro-prosthetic membrane is a common complication following Boston Keratoprosthesis (KPro) implantation, where a fibrous tissue layer forms behind the backplate. This membrane can significantly degrade visual acuity and obscure the view of the posterior segment and it can occur in as many as 50% of KPro patients with time.
When the membrane is relatively thin, a slit-lamp needle membranectomy offers a controlled, minimally invasive alternative that may be better than YAG capsulotomy and less invasive than surgical excision.
Procedure Technique
- Preparation: Ensure maximum pupillary dilation and apply topical anesthesia and ocular surface prep with povido-iodine, then apply a lid speculum
- Approach: A 30-gauge needle is bent at the hub to create a comfortable approach angle.
- Entry: Using the slit lamp for high-magnification visualization, the needle is passed through the donor stroma, peripheral to the KPro front plate.
- Disruption: The tip is positioned behind the backplate to engage the RPM. Using a sweeping motion, the surgeon creates a central opening in the visual axis and pushes the membrane inferiorly to clear the visual axis.
This technique allows for immediate visual recovery while avoiding the potential vitreous displacement or retinal traction sometimes associated with laser procedures.
