Use of trypan blue for penetrating keratoplasty

A comparative study: deep anterior lamellar keratoplasty for corneal dystrophies using two different donor stromal tissues

PURPOSE

This study aimed to present a comparison of early postoperative results of deep anterior lamellar keratoplasty (DALK) surgery performed using the two different corneal graft sources.

MATERIALS AND METHODS

This retrospective clinical study included the surgery performed on 26 eyes of 26 patients who underwent DALK for the stromal dystrophies. At the time of surgery, donor stromal tissue for DALK was sourced using the two different preparatory techniques. For 14 cases (Group 1), the donor grafts were prepared quickly by removing the descemet's membrane (DM) without much care after the exposure of the bare DM in the recipient cornea. For 12 cases (Group 2), the grafts for DALK surgery had already been prepared during a previous descemet's membrane endothelial keratoplasty (DMEK).

RESULTS

The groups differed statistically regarding the blue staining of the grafts at the time of surgery and on the first day post-DALK. The first day after surgery, 14 (100%) grafts were clear in Group 1, while eight (66.7%) grafts were clear and four (33.3%) were edematous in Group 2 (p = 0.019). Bubbling was performed in three (25.0% of Group 2) of the four cases on the first day post-DALK, while none of the patients in Group 1 underwent this procedure (p = 0.47). The postoperative increase in visual acuity was higher in Group 1 in the early postoperative period (p = 0.012).

CONCLUSION

During the early postoperative period, complications (as graft edema, detachment, re-bubbling) were observed more frequently in the DALK operations performed with stromal tissue having blue stain remaining from the DMEK performed on the same day and in the same session.

Trypan blue dye for anterior segment surgeries

Use of vital dyes in ophthalmic surgery has gained increased importance in the past few years. Trypan blue (TB) has been a popular choice among anterior segment surgeons mainly due to its safety, ease of availability, and remarkable ability to enable an easy surgery in difficult situations mostly related to visibility of the targeted tissue. It is being used in cataract surgery since nearly a decade and its utilization has been extended to other anterior segment surgeries like trabeculectomy and corneal transplantation. This review will discuss the techniques and outcome of TB dye-assisted anterior segment surgeries.

Use of trypan blue dye during conversion of deep anterior lamellar keratoplasty to penetrating keratoplasty

We describe a technique that uses trypan blue dye to identify residual recipient corneal stroma and Descemet membrane (DM) during conversion of deep anterior lamellar keratoplasty (DALK) to penetrating keratoplasty (PKP). After the host cornea is dissected, trypan blue dye (0.06%) is used to highlight the remaining host corneal stroma and DM, if any. In 8 DALK procedures that had to be converted to PKP because of DM perforation, trypan blue staining identified remnants of DM and parts of the posterior corneal stroma in 7 eyes. Improved visualization of the residual host tissue enabled complete excision and an overall optimal recipient wound profile.