Descemet-stripping automated endothelial keratoplasty: effect of anterior lamellar corneal tissue-on/-off storage condition on Descemet-stripping automated endothelial keratoplasty donor tissue.

PURPOSE: To compare the effect of storing Descemet-stripping automated endothelial keratoplasty (DSAEK) tissue with anterior lamellar corneal tissue (ALCT)-on versus -off. METHODS: An in vitro model was used with corneoscleral rims and DSAEK quality paired corneas. After microkeratome-assisted excision of ALCT, 4 pairs of corneas (8 eyes) were stored with the ALCT left on the stroma (on) and the others with ALCT off the stroma (off) for 24 hours in Optisol GS solution. A vital dye assay was used to identify devitalized and necrotic endothelial cells with alizarin red S and trypan blue. RESULTS: Corneal endothelial cell damage was observed in the ALCT-off specimens, whereas almost no staining was observed in the ALCT-on samples. In addition, the ALCT-off donor corneas were clinically edematous and opaque, whereas the ALCT-on corneas were clear. Moreover, Descemet membranes of ALCT-off samples were found to be loose and easily detached from the stroma, with many Descemet striae observed in the specimens. CONCLUSIONS: This study shows that endothelial damage occurs in ALCT-off corneas. We hypothesize that the absence of the Bowman layer may contribute to the damage, because it has been shown that the Bowman layer provides a barrier function. These data suggest that it is important to keep the ALCT/Bowman layer on the stromal side of the DSAEK graft as long as possible to avoid stromal swelling and endothelial damage.

Descemet-stripping automated endothelial keratoplasty (DSAEK): effect of nontoxic gentian violet marking pen on DSAEK donor tissue viability by using vital dye assay.

PURPOSE: To qualitatively assess the endothelial damage on Descemet-stripping automated endothelial keratoplasty (DSAEK) donor tissue resulting from a gentian violet marking pen. METHODS: An in vitro model was used, by using corneoscleral rims, DSAEK quality corneal donor tissue, and a gentian violet marking pen. After making a mark on the stromal side of a microkeratome-prepared DSAEK corneal button to confirm appropriate orientation of the donor tissue after insertion into the anterior chamber, the corneal tissue was returned to Optisol GS solution for 1 hour. A vital dye assay was used to identify devitalized and necrotic endothelial cells with alizarin red S and trypan blue. RESULTS: Corneal donor tissue evaluated with the gentian violet marking pen showed positive trypan blue staining, limited to the area marked with the gentian violet ink. CONCLUSIONS: Marking the DSAEK donor stromal surface with a gentian violet marker damages the endothelium. Surgeons should limit the size of the mark or use an insertion technique that avoids confusion about orientation of the donor cornea.

Descemet-stripping automated endothelial keratoplasty: effect of inserting forceps on DSAEK donor tissue viability by using an in vitro delivery model and vital dye assay.

PURPOSE: To qualitatively assess the extent and pattern of endothelial trauma on corneal donor Descemet-stripping automated endothelial keratoplasty (DSAEK) buttons resulting from DSAEK insertion forceps. METHODS: An in vitro model was used with corneoscleral rims, DSAEK quality corneal donor tissue, and DSAEK insertion forceps. After insertion of the donor button through the corneoscleral rim, a vital dye assay was used to identify devitalized and necrotic endothelial cells (with alizarin red S and typan blue). RESULTS: Corneal buttons evaluated with the forceps delivery model showed that, for each arm of the forceps, there were 2 parallel bands of purple/red staining. In addition, orthogonal wrinkles of scattered blue devitalized nuclei were seen in a parallel arrangement. CONCLUSIONS: The DSAEK insertion forceps resulted in a reproducible pattern of endothelial damage. A thorough understanding of iatrogenic endothelial trauma could result in improved forceps design and perhaps help mitigate the high rate of donor dislocation and graft failure in the future.

Adjunct devices for managing challenging cases in cataract surgery: pupil expansion and stabilization of the capsular bag.

PURPOSE OF REVIEW: Patients anticipate favorable surgical outcomes when having cataract surgery. The modern-day cataract surgeon should employ all necessary means to achieve this result. A working knowledge of adjunct devices for pupil expansion and capsular-bag stabilization can significantly improve surgical outcomes. RECENT FINDINGS: Adjunct devices for pupil expansion include the Beehler pupil dilator, nylon iris hooks, and pupillary rings, including the Perfect Pupil, the Graether 2000, and the Morcher pupil dilator. Capsular-bag stabilization can be accomplished with capsular tension rings, capsular tension segments or iris hooks. The recent literature on these devices is reviewed. SUMMARY: Impaired visualization through a small pupil and poor tissue stabilization increases the chance of tissue damage, retained nuclear material, and vitreous loss. Fortunately, inadequate mydriasis and instability of the capsular bag can be managed safely with the use of adjunct tools. Preoperative planning, familiarity with available tools, and accessibility of these devices in the operative setting is necessary.

Adjunct devices for managing challenging cases in cataract surgery: capsular staining and ophthalmic viscosurgical devices.

PURPOSE OF REVIEW: Cataract surgeons should employ all reasonable technology to facilitate safe and consistent outcomes. Knowledge of adjunct devices to enhance visualization of the capsular bag and appropriate use of ophthalmic viscosurgical devices allow for enhanced protection of intraocular structures and reduced rates of complication. RECENT FINDINGS: Trypan blue is US Food and Drug Administration-approved for facilitating visualization of the anterior capsule. Animal data demonstrate Brilliant Blue G to be an effective capsular stain with a superior safety profile. Healon5 is a safe viscosurgical device that is particularly useful in children, poorly dilating pupils, intraoperative floppy-iris syndrome, and intumescent cataracts. The viscoadaptivity of Healon5 enables its utility throughout the procedure of cataract extraction. The recent literature on capsular dyes and advances in ophthalmic viscosurgical technology is reviewed. SUMMARY: Inadequate capsular visualization and poor tissue stabilization/protection increase the chance of discontinuous capsulorhexis, retained nuclear material, vitreous loss and corneal decompensation. Utilization of adjunctive tools in the setting of challenging cataract cases can significantly limit adverse intraoperative outcomes and result in reproducible surgical success.