Thicker amniotic membrane a promising solution to improve ocular surface outcomes
Grafting a thicker amniotic membrane onto the ocular surface may be a promising solution for patients who experience graft failure or require ocular surface reconstruction after penetrating keratoplasty. A product from IOP Ophthalmics (Ambio5) is a dehydrated amniotic membrane tissue that seems to improve the outcomes following amniotic membrane transplantation.
"Ambio5 is a very effective adjunct in the reconstruction and maintenance of the ocular surface after penetrating keratoplasty," said Dr Jai G. Parekh, MBA, FAAO. He is chief of cornea and external diseases and director of research, St Joseph's Regional Medical Center, Paterson, New Jersey, USA, clinical assistant professor of ophthalmology, New York Eye and Ear Infirmary, New York, USA, and managing partner of BrarParekh Eye Associates, Woodland Park/Edison, New Jersey, USA.
The graft is a third-generation amniotic membrane technology made from the submucosa of the placenta. It provides a thicker allograft that has preserved cellular components and dense adjacent and connective matrices. The thickness of the graft is 110 µm or greater.
He has used this product successfully in more than 200 cases and described a particularly difficult case in which the patient had undergone a previous graft rejection and had a complicated medical history.
A 78-year-old woman had a complex ocular history that included a failed corneal transplant, herpes simplex keratitis, neurotrophic keratitis and Salzmann's nodules.
When she presented, the graft in her left eye was failing and the status of the ocular surface was poor. The vision in the left eye was hand motions. She described severe ocular irritation with pain, tearing, a foreign-body sensation, and occasional redness. The ocular surface had 4+ superficial punctate keratopathy (SPK), irregular epithelium, two Salzmann's nodules and a failing corneal graft. The herpetic disease was inactive at the time of her presentation.
The patient underwent penetrating keratoplasty and ocular surface reconstruction with the membrane allograft. After penetrating keratoplasty, the amniotic membrane graft was cut to create a rectangular button that was layered onto the new ocular surface. The surgery included the perilimbal conjunctival area and new corneal graft. The graft was hydrated with balanced saline solution (BSS) and then secured in place with four corner 8-0 Vicryl sutures and fibrin glue (Tisseel VH, Baxter International). A bandage contact lens was applied at the end of the surgery.
Dr Parekh said that on postoperative day 1, the visual acuity in the operated eye was 20/400 and the ocular surface was intact. The patient was instructed to apply frequent topical corticosteroids [difluprednate 0.05% (Durezol, Alcon Laboratories)], a fluoroquinolone drop [besifloxacin 0.06% (Besivance, Bausch + Lomb)], and an ointment [ciprofloxacin hydrochloride ophthalmic ointment (Ciloxan ophthalmic ointment, Alcon Laboratories)] at night.
She also applied a daily topical nonsteroidal agent [bromfenac 0.09% (Bromday, ISTA Pharmaceuticals)], a topical antiviral gel [ganciclovir ophthalmic gel 0.15% (Zirgan, Bausch + Lomb)], preservative-free artificial tears (Optive Preservative-Free; Allergan), and prophylactic oral antiviral agents.
The left lower punctum was plugged to aid with restoration of her ocular surface. By 1 week postoperatively, the ocular surface was maintained.
By 2 months postoperatively, the best-corrected visual acuity was 20/100 and the ocular surface and the graft were intact. The patient had almost no SPK, epithelial irregularity, or Salzmann's nodules.
Importantly, there were no signs of corneal transplant rejection, Dr Parekh said.