Purpose: To evaluate amniotic membrane (AM) tissue morphology and corneal epithelial healing in human eyes after amniotic membrane transplantation (AMT), using laser scanning in vivo confocal microscopy (IVCM).
Patients and methods: Twenty eyes of twenty patients, treated with single layer epithelial side up AMT for chemical burns in the acute stage (n=8) and persistent corneal epithelial defect (n=12) were studied by serial IVCM post AMT until complete re-epithelization. Changes in morphology of transplanted amniotic tissue and healing corneal epithelium were noted. AM and corneal epithelial cell density was calculated using image analysis software.
Results: IVCM enabled visualisation of transplanted AM and of regenerating epithelial cells under the AM. The mean AM epithelial cell density, one day after transplant, was 4613 ± 380 cell/mm2. Average AM epithelial thickness was 35 ± 4 μm, while AM stromal thickness was 116 ± 31 μm. The amniotic stroma appeared to be composed of a superficial dense fibrous layer and a deeper loose reticular network of fibers. Amniotic epithelium was lost within 15 days of transplant and complete re-epithelisation of the corneal surface was achieved between one and four weeks.
Conclusions: Laser scanning IVCM is a useful method for evaluating AM tissue morphology, degradation and corneal epithelial healing after AMT for different clinical indications. When the amniotic membrane acts as a patch, i.e. epithelial cells migrate under rather than over the membrane, the membrane disintegrates and is lost.
- amniotic membrane
- confocal microscopy
- corneal epithelium
- ocular surface