Ocular burn treatment
Most patients with moderate to severe limbal stem cell deficiency (LSCD) due to corneal burns experienced reduced ocular symptoms for up to 10 years after treatment with an implant
Most patients with moderate to severe limbal stem cell deficiency (LSCD) due to corneal burns experienced reduced ocular symptoms for up to 10 years after treatment with an implant containing limbal stem cells donated and expanded from their fellow eyes, Paolo Rama MD told the 7th EuCornea Congress in Copenhagen, Denmark.
The majority of patients without stromal scarring or who underwent keratoplasty after implantation also achieved clinically significant improvements in visual acuity (VA).
The patients, most of whom had failed previous surgical interventions, were treated with Holoclar® (Chiesi Farmaceutici, Italy), a transparent, circular, fibrin sheet containing autologous human corneal epithelial stem cells, said Dr Rama, of San Raffaele Scientific Institute, Milan, Italy.
The long-term outcome study examined 95 patients, 22 female and 73 male, followed from one to 10 years after implantation, with a median 2.8 years. Best corrected visual acuity (BCVA) was 20/200 or less in 92.2%, with 38 at finger counting and 35 at hand movement. Overall, 40% had one or more ocular symptom, including pain, burning or photophobia. Nearly 90% had failed at least one previous surgery and 40% had failed keratoplasty.
The treatment consists of harvesting a small quantity of donor cells, about 1-2mm2, from patients’ fellow eyes. These are sent to a lab where they are expanded in the fibrin media, and sent back for implant. In some cases, the treatment is sufficient to restore sight in the absence of deep corneal stroma damage. Combined with corneal transplants it can restore a normal cornea for previously incurable deep corneal burns. It is the only EMA-approved medicinal product for treating LSCD due to ocular burns.
The primary endpoint in Dr Rama’s study was a stable corneal epithelium without significant recurrence of corneal neovascularisation at one year after the last treatment. Secondary efficacy endpoints were relief of ocular symptoms and improvement in BCVA.
At their last visit, 72 patients (or nearly 76%) were judged successful based on the presence of mild or no superficial corneal neovascularisation, and trace or no epithelial defects, Dr Rama reported. The percentage of patients reporting ocular symptoms also dropped to 11.6% from 40%, a decrease of 71%.
Among 40 patients who had keratoplasty after the implant, 87.5% gained more than three Snellen lines of VA, Dr Rama said. Of 13 patients without stromal scarring, 69% gained three or more lines, while 44.6% of those with stromal scarring had similar vision gains. Median time from implant to keratoplasty was 3.4 years.
Of 157 patients treated with the implant in three retrospective studies, 43 (or 18.5%) were treated for at least one adverse drug reaction, with three of these considered serious, Dr Rama said. Conjunctival haemorrhage was the most common adverse reaction, seen in 4.5% of cases, followed by corneal epithelium defect in 3.2%, eye pain, eye haemorrhage and blepharitis in 2.6% each, and glaucoma in 1.9%. The three serious adverse events were vasovagal syncope, ulcerative keratitis and corneal perforation.
“Holoclar was well-tolerated, with the main adverse events limited to the eye and mostly reflecting events associated with the surgical procedure or loss of efficacy,” Dr Rama said. It is a viable treatment for the permanent restoration of LSCD following ocular burns, demonstrating success at up to 10 years, he concluded.
Paolo Rama: firstname.lastname@example.org