STEM CELL EXPANSION

Ocular surface reconstruction using expanded limbal stem cell culture combined with penetrating keratoplasty can restore good vision even in some cases with severe acid burns, said Merce Morral MD, PhD, Barcelona, Spain at the 19th ESCRS Winter Meeting in Istanbul, Turkey.
“Eyes with total limbal stem cell deficiency require several steps to restore good visual acuity,” Dr Morral added.
She presented a case study involving a 31-year-old patient who had severe acid-burns in both eyes. His right eye regained a visual acuity of 20/20 following several eyelid reconstructive surgeries. However, his left eye had a vision of only 20/400 due to severe limbal stem cell insufficiency together with corneal conjunctivalization and vascularization.
Dr Morral and her associates from the Institut de Microcirugia Ocular (IMO), Barcelona, Spain, therefore decided to treat the eye in a two-stage procedure. The first stage involved repairing the epithelial defect using tissue-culture expansion of limbal stem cells grown on fibrin gel. The second step was to perform penetrating keratoplasty after the cornea had re-epithelialised completely.

Tissue expansion
They obtained the stem cells for tissue expansion from the patient’s right eye and allowed it to grow for three weeks on the fibrin gel substrate. Prior to placing the tissue in the patient’s limbal stem cell-deficient left eye, they performed 360-degree peritomy of the conjunctival tissue and removed all of the fibrovascular outgrowth from the ocular surface by means of blunt dissection with scissors. They then placed the autologous epithelial tissue graft over the denuded cornea and underneath the conjunctival peritomy. 
To enhance epithelialization and limit inflammation, they sutured amniotic membrane on top of the graft and performed a temporary tarsorrhaphy. One week postoperatively, the epithelium had regenerated and the eye was calm and without epithelial defects and the patient was pain free. However, three months postoperatively vision remained at 20/400 because of corneal scarring.
The patient subsequently underwent a penetrating keratoplasty. Because of the danger of poor re-epithelialization, they again placed an amniotic membrane patch and, to make it last longer on the eye, the patient wore a bandage contact lens on top of it.
At one year’s follow-up, when all the sutures had been removed, the eye had an uncorrected visual acuity of 20/25. The patient continues to use a bandage contact lens to protect the cornea from abrasions that might result from continual contact with the patient’s eyelids, which could not be repaired completely.

Merce Morral: merce.morral@gmail.com