Interfacial fluid dynamics in Descemet's membrane endothelial keratoplasty

Session Details

Session Title: Moderated Poster Session: Cornea

Venue: Poster Village: Pod 2

First Author: : S.Koay UK

Co Author(s): :    M. Lewis   R. Angunawela                    

Abstract Details

Purpose:

Partial detachments in DMEK have been reported to most frequently occur inferiorly. This study was performed to investigate the forces acting on the transplanted DMEK graft edge at the aqueous fluid and anterior chamber air/gas bubble interface. This would allow us to determine if surface tension effects may be a contributing factor in DMEK detachments.

Setting:

Theoretical mathematical computational fluid dynamics model

Methods:

A mathematical computational fluid dynamics model was designed to simulate surface tension effects at the DMEK graft between the anterior chamber bubble and aqueous fluid. Changes in surface tension effects when the patient sits up or lies down were also analysed, assuming the gas bubble moves such that half the interface crosses the edge of the graft. The eye was abstracted to a sphere.

Results:

The maximum force acting at the edge of the DMEK graft is 0.2mN; as the patient sits up or lies down, the movement of the gas bubble across the inferior edge of the graft leads to a maximum of 0.2mN of force acting on the inferior graft edge, which may induce detachment. Repetitive movement of the meniscus may thus contribute to the propagation of predominantly inferior DMEK detachments.

Conclusions:

This mathematical fluid dynamic model demonstrates that a negative force vector toward the centre of the eye occurs at the air bubble meniscus interface at the inferior DMEK graft edge. This force may be sufficient to pull the inferior graft edge away and may explain why partial DMEK graft detachments are predominantly inferior. It may therefore be advantageous to ensure the meniscus of the bubble is above the inferior edge of the graft postoperatively, to reduce the risk of repetitive air bubble movement propagating a detachment.

Financial Disclosure:

None