[Multilayer amniotic membrane transplantation for corneal ulcers not treatable by conventional therapy - a prospective study of the status of cornea and graft during follow-up].

PURPOSE

The purpose of this prospective clinical study was to evaluate the condition of the cornea (epithelium and vascularization) and the membrane presence and retraction during follow-up after amniotic membrane transplantation in patients with persistent corneal ulcers.

PATIENTS AND METHODS

Between June 1999 and November 2000 AM transplantation was performed in 30 consecutive patients (average age 59 +/- 17 years) with corneal ulcers refractory to clinical treatment. We evaluated the clinical diagnosis, localisation, size and depth of the ulcers, condition of the ocular surface and visual acuity before and after surgery. After complete removal of the epithelium and pannus, one (n=11), two (n=17) or three (n=2) layers of amniotic membrane were fixed with multiple interrupted sutures, depending on the depth of the lesion. A therapeutic contact lens was applied in most eyes and removed after one month. The most frequent diagnoses were chemical burn (5 x lime, 1 x lye and 1 x liquid aluminium), 7 x herpes, 3 x polyarthritis and 3 x blepharo-keratoconjunctivitis in neurodermitis. The ulcers had a medium length of 4.9 +/- 3.2 mm, a width of 3.5 +/- 3.0 mm and a depth ranging between 30 % and 95 % (68 +/- 21 %).

RESULTS

Complete epithelial closure was achieved in 27 of 30 eyes (90 %). In 4 eyes a recurrent epithelial defect occurred after initial closure. At the 1-, 3- and 6 month follow-up the amniotic membrane was present in 93 %, 73 % or 30 %, respectively, but was more or less retractet in 52 %, 58 % or 67 %, respectively. A complete corneal epithelium was noted in 79 %, 89 % or 90 % of eyes, respectively. However, corneal neovascularization was observed in 24 %, 58 % or 60 % of eyes. Visual acuity was </= 20/400 in 60 % eyes preoperatively, but in 69 % after 3 months and in 78 % after 6 months of follow-up.

CONCLUSION

In persistent corneal ulcers, amniotic membrane transplantation should be considered in early stages to achieve permanent epithelial closure in a less inflamed eye thus avoiding penetrating keratoplasty à chaud or conjunctival flaps. However, in eyes with broad descemetocele especially following chemical burns, this treatment modality does not seem to be effective.