Manual Top Hat Wound Configuration for Penetrating Keratoplasty

Tuck In Femtosecond Laser Assisted Anterior Lamellar Keratoplasty (T-FALK) for the Management of Superficial Anterior Corneal Scars-A Modified Technique

PURPOSE

To report a modified sutureless and glue-less technique, termed tuck in femtosecond laser assisted anterior lamellar keratoplasty (T-FALK), and to achieve a good graft-host junction apposition.

METHODS

This is a prospective interventional case series of 15 eyes of 15 patients who underwent T-FALK. Depth of the anterior corneal scar was assessed using anterior segment optical coherence tomography (ASOCT). The donor and recipient lenticules were prepared using femtosecond laser. After removing the recipient anterior scarred lenticule, the transparent donor lenticule was positioned on the recipient bed and margins tucked in under the recipient cornea. A bandage contact lens was applied for 3 weeks. Postoperatively, topical antibiotic and steroid combination eye drops were given, and the assessment of healing of the graft-host junction was done using ASOCT.

RESULTS

A total of 15 patients (8 men and 7 women) underwent T-FALK. Six patients had superficial corneal opacities after healed microbial keratitis, 5 patients had spheroidal corneal degeneration, 3 patients had Salzman nodular degeneration, and 1 patient had vortex keratopathy. No intraoperative or postoperative complications were noted during T-FALK. All patients had good graft-host junction apposition postoperatively, as demonstrated by ASOCT.

CONCLUSIONS

Sutureless and glue-less T-FALK can be the best way ahead for management of superficial anterior corneal scars with good visual outcome.

Shaped corneal transplantation surgery

Since its inception in 1905, keratoplasty techniques have continuously evolved. Shaped keratoplasty procedures have allowed corneal surgeons to use complex graft-host junctions and non-circular graft designs to optimise wound strength and healing, facilitate early suture removal and expedite visual rehabilitation. While this was initially limited to penetrating procedures, shaped lamellar keratoplasty techniques have since emerged. Furthermore, the arrival of femtosecond laser has dramatically increased the range of graft designs available to surgeons, due to the technology's ability to precisely cut complex wound edges. This review describes the broad range of shaped keratoplasty grafts currently available and elaborates on their respective advantages and disadvantages in relation to conventional keratoplasty.

Application of the femtosecond laser LASIK microkeratome in eye banking

PURPOSE OF REVIEW

To review the literature for recent advancements in the femtosecond laser technology with regard to its applications in corneal transplantation and eye banking.

RECENT FINDINGS

Advancements in corneal surgery have encouraged the use of disease-specific corneal subcomponents, utilized in procedures such as anterior-lamellar keratoplasty and endothelial keratoplasty, instead of traditional transplant procedures to minimize adverse effects of penetrating keratoplasty. Femtosecond laser microkeratomes can precisely create flaps for such transplant procedures, achieve better wound stability, and promote healing by shaped wound configurations. Laser microkeratomes have been compared to traditional mechanical microkeratomes for keratoplasty procedures from various aspects and are superior in some aspects and offer unique capabilities.

SUMMARY

Femtosecond laser applications in eye banking include preparation of donor and recipient corneas for use in penetrating keratoplasty, anterior-lamellar keratoplasty, and endothelial keratoplasty. Advantages of femtosecond laser microkeratomes include higher precision of the cut, ability to achieve thinner flaps, and wound configurations that allow greater wound stability, shorter recovery time, and less postoperative pain. However, cost and availability at the eye-bank level may hinder widespread and immediate application.

Comparison of three different techniques of corneal transplantation for keratoconus

PURPOSE

To compare the visual outcomes following deep anterior lamellar keratoplasty (DALK), penetrating keratoplasty (PK), and manual top-hat PK (TH-PK) in subjects undergoing corneal transplantation for keratoconus (KC).

DESIGN

A retrospective comparative case series.

METHODS

settings: Cornea clinic at the Toronto Western Hospital. study population: Fifty patients who underwent corneal transplantation for KC: 17 eyes underwent DALK, 20 eyes underwent traditional PK, and 13 had TH-PK. main outcome measures: Preoperative and postoperative uncorrected and best spectacle-corrected visual acuity (UCVA, BSCVA), high-order aberrations (HOA), complication rate, and endothelial cell counts.

RESULTS

The median BSCVA at 12 months follow-up was 20/40 in the DALK eyes and 20/30 in the traditional PK and TH-PK eyes. The mean final spherical equivalent power in the three groups was less than -1 diopter (D). The median astigmatism was less than 3.5 D in the three groups. Complication rates were similar for three groups, although the DALK group tended toward more complications. Although DALK and TH-PK procedure results in significantly shorter time to suture removal (P < .01), they caused increased levels of HOAs (P = .02). Endothelial cell counts at 12 months were significantly higher in DALK and TH-PK eyes when compared to the traditional PK eyes (P < .001).

CONCLUSIONS

DALK, PK, and TH-PK provide comparable visual outcomes in keratoconus patients. Although DALK and TH-PK induce more HOA, they speed up the time to suture removal and provide higher endothelial cell density at one year of follow-up.