Active Pedicle Epithelial Flap Transposition Combined with Amniotic Membrane Transplantation for Treatment of Nonhealing Corneal Ulcers

Visual Acuity and Number of Amniotic Membrane Layers as Indicators of Efficacy in Amniotic Membrane Transplantation for Corneal Ulcers: A Multicenter Study

BACKGROUND

To evaluate new indicators in the efficacy of amniotic membrane transplantation (AMT) for non-healing corneal ulcers (NHCUs).

METHODS

Retrospective, multicenter study. In total, 223 AMTs for NHCU in 191 patients were assessed. The main outcomes studied were the success rate of AMT (complete re-epithelization), postoperative visual acuity (VA) gain, and number of AM layers transplanted.

RESULTS

The overall AMT success rate was 74.4%. In 92% of our patients VA stability or improvement. Postoperative VA was significantly higher than preoperative VA in the entire cohort (p < 0.001) and in all etiological groups of ulcers (post-bacterial, p ≤ 0.001; post-herpetic, p ≤ 0.0038; neurotrophic ulcers, p ≤ 0.014; non-rheumatic peripheral, p ≤ 0.001; and ulcers secondary to lagophthalmos and eyelid malposition or trauma, p ≤ 0.004). Most participants (56.5%) presented a preoperative VA equal to or less than counting fingers (≤0.01). Of these, 13.5% reached a postoperative VA equal to or better than legal blindness (≥0.05) after AMT. A higher success rate was observed in the monolayer than in the multilayer AMT (79.5% and 64.9%, respectively; p = 0.018). No statistically significant values were found between the number of layers transplanted and VA gain (p = 0.509).

CONCLUSION

AMT is not only beneficial in achieving complete re-epithelialization in NHCUs but also in improving postoperative VA; these improvements are independent of etiologies of ulcers. Furthermore, the use of monolayer AMT seems to be a more appropriate option than multilayer AMT for NHCU since the multilayer AMT did not present better outcomes (success rate and VA gain) compared to monolayer AMT in the different types of ulcers studied.

Experimental study of trabecular tissue repair for corneal defect in rabbits

AIM

To investigate the mechanism and effect of trabecular tissue repair for corneal defect, and to provide a theoretical basis for its clinical application.

METHODS

Trabeculectomy was performed on 40 (80 eyes) of 70 New Zealand white rabbits. Take trabecular tissue for backup. Thirty (30 eyes) corneal defect models were made, trabecular tissue was filled in the corneal defect, and the oblique cross stitch was used to suture the corneal laceration and debridement. Anterior segment image and optical coherence tomography (OCT) were performed at the time 1d, 1wk, 1 and 3mo after the model was made. After the observation, the cornea was taken and stained with trypanosome blue-alizarin red and the pathological tissue was examined.

RESULTS

Observation 1wk after surgery, the area of corneal defect was edema, but the corneal curvature was basically normal, and the anterior chamber existed under slit lamp. After 3mo of observation, most corneal defects were repaired in the form of corneal leucoma and corneal macula (73.3%), the filled trabecular tissue gradually became transparent, fused tightly with the corneal tissue, and the corneal curvature was relatively smooth. But in one case, the trabecular planter was partially detached, no serious complications such as corneal laceration occurred after the stitches were removed.

CONCLUSION

The trabecular tissue structure is similar to the corneal, and it can be used as a substitute for the corneal tissue defect by providing fiber scaffolds and cell amplification differentiation, and lay a foundation for the second-stage surgical treatment.