Exploring the precision of femtosecond laser-assisted descemetorhexis in Descemet membrane endothelial keratoplasty

Descemet stripping only in Fuchs' endothelial dystrophy without use of topical Rho-kinase inhibitors: 5-year follow-up

OBJECTIVE

To describe 5-year postoperative outcomes of a small series of Fuchs' endothelial dystrophy (FED) patients who underwent Descemet stripping only (DSO) with a scraping technique.

METHODS

DSO technique and early clinical outcomes of 5 patients with mild central FED were previously reported. In the same cohort of patients, corrected distance visual acuity, central corneal ultrasound pachymetry, refractive spherical equivalent, endothelial cell count, slit-lamp photography, and corneal Scheimpflug tomography were obtained at baseline, 6 months, and 1 and 5 years postoperatively. No patient used topical Rho-kinase inhibitors at any point in time.

RESULTS

One patient (20%) failed to clear the early postoperative edema and 1 patient (20%) developed corneal decompensation 1 year after DSO. Both patients underwent successful Descemet stripping automated endothelial keratoplasty. The remaining 3 patients had stable corrected distance visual acuity, progressive reduction of corneal ultrasound pachymetry, and mild myopic shift of the refractive spherical equivalent over the follow-up time. An improvement in posterior stromal opacities and irregular astigmatism was observed, whereas posterior elevation at Scheimpflug tomography remained unchanged.

CONCLUSION

At 5 years postoperatively, DSO with a scraping technique and without Rho-kinase inhibitors resulted in sustained clinical amelioration of 3 of 5 patients (60%) with mild FED.

Femtosecond laser-assisted descemetorhexis for Descemet membrane endothelial keratoplasty: a cell- and tissue-based ex-vivo analysis in terms of precision and safety

PURPOSE

To analyze precision and safety of femtosecond laser-assisted descemetorhexis as well as postoperative corneal wound healing in human ex vivo specimens.

SETTING

Department of Ophthalmology, University Hospital, LMU Munich, Munich, Germany.

DESIGN

Experimental ex vivo study.

METHODS

Four donor corneas underwent femtosecond laser-assisted descemetorhexis. The descemetorhexis was performed using the LDV Z8 femtosecond laser followed by live/dead staining, phase contrast microscopy and scanning electron microscopy. The descemetorhexis parameters were set using a modified optical coherence tomography image capturing of 8 segments within a focus of 100 μm at the posterior corneal stroma (reversed capsulotomy program).

RESULTS

Live/dead sample staining analysis demonstrated that the femtosecond laser had minimal impact on the vitality of surrounding endothelial cells. Phase contrast microscopy and scanning electron microscopy evaluation showed that the laser produced precise, clear-cut edges leaving no stromal tissue bridges.

CONCLUSIONS

Femtosecond laser-assisted descemetorhexis could serve as a safe and precise technique with only minimal endothelial cell damage. To minimize stromal damage, further laser energy profile adjustments are necessary to optimize corneal treatment within different stages of corneal tissue swelling.

Laser-assisted corneal transplantation surgery

Corneal transplant surgeries have a broad range of indications with outcomes largely dependent on surgeon experience. Traditional manual techniques have certain limitations pertaining to the preparation of donor tissue and the recipient bed that might affect the predictability of visual outcomes. Use of lasers for keratoplasty procedures not only improves the repeatability and consistency of the technique, but also enables the surgeon to control the thickness and shape of the transplant tissue tailored to the specific condition. Despite the advantages, cost-effectiveness and technical know-how remain the major challenges. We discuss the various techniques of laser-assisted keratoplasties with respect to their methods, precision, and efficacy in various corneal indications.

Update on the Surgical Management of Fuchs Endothelial Corneal Dystrophy

Fuchs endothelial corneal dystrophy (FECD) is the most common posterior corneal dystrophy and the leading indication for corneal transplantation in the United States. FECD is slowly progressive, and patients develop gradual corneal endothelial decompensation, eventually resulting in failure of the endothelium to maintain corneal deturgescence. Medical management consists of topical hyperosmotic agents to facilitate dehydration of the cornea, but surgical intervention is often required to regain corneal clarity. The surgical management of FECD has evolved over the past two decades as corneal transplantation techniques have allowed for more selective keratoplasty and replacement of only the diseased layers of the cornea. Prior surgical management consisted of penetrating keratoplasty (PK) that carried significant intraoperative risks associated with "open sky" as well as postoperative risks of graft rejection, wound dehiscence, postoperative astigmatism, and prolonged visual rehabilitation. In the past 15 years, endothelial keratoplasty (EK) has become the treatment of choice for endothelial disease, significantly reducing the risks associated with the surgical treatment of FECD. Here we discuss the current surgical management of FECD, including the introduction of Descemet stripping only (DSO), and highlight future investigative efforts.