Posters

Curvature and pachymetry maps may guide the location and deepness of the cannula used to form the big bubble type 1 in deep anterior lamellar keratoplasty (DALK)

Poster Details

First Author: C.Arce BRAZIL

Co Author(s): A. Forsetto   H. Pfluck   L. Sampaio   N. Pereira           

Abstract Details

Purpose:

To present the reasoning of how 10-mm-diameter anterior tangential and pachymetry maps from the dual Scheimpflug and Placido corneal analyzer may guide and make simpler the formation of a big bubble type 1 during DALK

Setting:

The Eye Bank & Ophthalmic Hospital of Sorocaba, Sorocaba, Sao Paulo, Brasil

Methods:

With the 1D-CGA German scale of Galilei G4/G6 we were able to identify an extreme peripheral flat zone in normal corneas and, more frequently in corneas with keratoconus. In keratoconus such peripheral flat zone is very different than the central ectasic and bulged zone and both are delimited by a yellow-green zone in maps. This lecture includes few videos showing the air injection and formation of the big bubble during Galilei Guided-DALK performed in eyes with keratoconus. The tip of cannula was localized at a selected place within the yellow green color zone that surrounds the central ectasic zone. The thickness of such point was used to guide the deepness of the incision made for the air injection.

Results:

The extreme flattening peripheral (blue-light blue) zone observed on anterior tangential maps seemed to be related with the also peripheral Dua layer which uses not to separate easy from the rest of the stroma. On the other hand, the central ectasic (orange-red) zone delimited in these maps seem to be related with the part of the Dua layer that can be individualized and separated easier from the rest of stroma. Selecting a location within the narrow and easy observed yellow-green intermediary zone on maps, we obtained easier and with less resistance the preferred type 1 big bubble when air is injected into the stroma during DALK. Our results suggest that the injection on peripheral flat zone as more probabilities to produce big bubble type 2 or mixed.

Conclusions:

Our findings support the suggestion that the central ectasic zone observed in these maps in corneas with keratoconus might be related with the formation of the big bubble type 1, while the peripheral flatter zone may correspond to the peripheral Dua layer which is more difficult to separate from the rest of the stroma and would produce more resistance to the air injection. We consider that there are more probabilities to form the preferred big bubble type 1 when the tip is located at a selected yellow-green place observed in the Galilei anterior tangential maps with appropriate color scale

Financial Disclosure:

... receives consulting fees, retainer, or contract payments from a company producing, developing or supplying the product or procedure presented, ... travel has been funded, fully or partially, by a company producing, developing or supplying the product or procedure presented