Synthetic Implant Offers Corneal Blindness Solution

Surgeons have successfully implanted the first keratoprosthesis that utilizes a polymeric scaffold for biointegration within ocular tissue, according to an Eye (Lond) publication. The device, the CorNeat KPro implant, is a synthetic cornea designed to treat corneal blindness. It incorporates an external integrating skirt composed of electrospinning carbonated polyurethane fibers. This skirt aids with assimilating the synthetic optics within the ocular tissue. 

Previous prostheses have been designed to integrate with diseased corneal remnants. But the CorNeat KPro is implanted underneath the conjunctiva and employs highly vascularized tissue, abundant with fibroblasts for superior wound healing, the study explains. The manufacturer expects this design to result in long-term biointegration. 

The device’s “scaffold design promotes the migration of fibroblasts from Tenon’s capsule into the skirt, leading to long-term integration of the device — bypassing the prosthesis-host cornea interface that exists in other prostheses,” researchers explain.

In this case, a patient with bilateral corneal opacification secondary to multiple failed grafts was recruited at the Rabin Medical Center in Israel. The patient had an ocular surgical history of bilateral penetrating keratoplasty, bilateral anterior chamber intraocular lens (IOL) implantation, cataract extraction, and Descemet’s stripping automated endothelial keratoplasty. The patient also had glaucoma.

One day after surgery, the visual acuity was 1/20 and tactile intraocular pressure (IOP) was normal. Macular optical coherence tomography (OCT) showed thinning and disorganized inner retinal layers, subfoveal disturbance in the ellipsoid zone, and mild intraretinal cystic changes.

At subsequent follow-ups, visual acuity ranged from 1/16 to 1/20 and intraocular pressure remained within normal range. The implant remained well tolerated and properly positioned. Mild conjunctival retraction was observed at 4 mm to 5 mm over the nasal and superior part of the device skirt. OCT examinations revealed similar findings as during the first follow-up.

At 6 months, a fine membrane over the inferior part of the intraocular lens anterior chamber was found and successfully removed using a laser.

At 12 months, visual acuity was stable at 1/16.

The major limitation of this study was that the potential recovery in visual acuity was limited for this patient given the clinical history. The study authors speculated that eyes with isolated corneal pathology would likely regain better visual acuity with the CorNeat KPro implant. The implant is suitable for phakic and pseudophakic eyes and has a matching intraocular lens which can be implanted before or after the corneal device.

“The CorNeat KPro offers an alternative to current KPro procedures, with potential advantages including subconjunctival integration, wide visual field and favorable cosmetic results. This is the first-in-human implantation of the CorNeat KPro,” the report explains. “This initial experience holds promise for a potential breakthrough in the treatment of corneal disease not amenable to standard corneal transplantation. Longer follow-up and additional implantations are necessary to better assess the long-term safety and efficacy of this device.”

Disclosure: The study was funded by CorNeat Vision Ltd. Multiple authors declared affiliations with industry. Please refer to the original article for a full list of disclosures.

Reference

Bahar I, Reitblat O, Livny E, Litvin G. The first-in-human implantation of the CorNeat keratoprosthesis. Eye. Published online June 1, 2022. doi:10.1038/s41433-022-02105-3