Posters

Pachymetry-assisted deep anterior lamellar keratoplasty

Poster Details

First Author: V.De Rojas SPAIN

Co Author(s):    I. López   J. Pombo   M. Álvarez   A. Gómez   M. López  

Abstract Details

Purpose:

To evaluate the frequency of big bubble formation using a modification of pachymetry-assisted deep anterior lamellar keratoplasty (DALK).

Setting:

Ophthalmology Department, Complexo Hospitalario Universitario A Coruña, Spain.

Methods:

Prospective study including consecutive cases of pachymetry-assisted DALK performed between September 2013 and February 2014 by two experience surgeons. A circular mark (7.75 to 8.25 mm in diameter) is made with a disposable trephine. Intraoperative pachymetry is then performed outside but adjacent to this mark at eleven o´clock position. A 400 micron depth partial trephination is carried out. Using a diamond knife set at 85% of the pachymetry reading, a 1 mm incision is made between 11 and 12 o´clock positions outside and parallel to the partial trephination. A deep corneal pocket is then created at the bottom of the incision using a dissector. The Sarnicola spatula is inserted into the pocket and advanced until it reaches the center or the cornea. The spatula is then removed and the cannula, attached to a 5-cm3 syringe filled with air, is introduced into the corneal tunnel so that air can be injected deep in the stroma, near Descemet membrane. Once the big bubble appears, surgery is completed as usually. Should the formation of big bubble fails, manual dissection to a descemetic plane is performed. Videos showing the most important details of the technique are included. Outcome measure: frequency of big-bubble formation.

Results:

Twelve eyes of 12 patients underwent pachymetry-assisted DALK (10 females and 2 males, mean age 48.1 ± 17.3 years (range 28 - 83 years)). Indications for DALK were keratoconus in 10 cases (one of them with leucomas) and leucomas of infectious ethiology in 2 cases. The frequency of big bubble formation was 75% in the whole series (9 out of 12 cases), 80% (8 out of 10) in the keratoconus group and 88.88% (8 out of 9) in cases of keratoconus without leucoma. Two of the three cases in which the formation of big bubble failed had leucomas (one of them in keratoconus). In these three cases, the tunnel performed at 85% of corneal thickness allowed to reach more easily the descemetic plane, shortening the manual dissection case time. Microperforations occurred in two cases but none of them required conversion to penetrating keratoplasty.

Conclusions:

Pachymetry-assisted DALK achieves a high frequency of big bubble formation. The presence of corneal leucoma could be risk factor for failure in obtaining the big bubble, but a larger series of cases would be necessary to confirm this finding. FINANCIAL INTEREST: NONE