Pre-Descemet’s Endothelial Keratoplasty

  • Soosan Jacob

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This video will demonstrate the steps to performing a PDEK graft: loading the graft, making a bubble, preparing the recipient eye, and closing the incision. As the names imply, DMEK refers to transplantation of the Descemet’s Membrane and endothelium whereas PDEK refers to transplantation of pre-Descemet’s layer, Descemet’s membrane and endothelium. The video will carefully demonstrate PDEK technique, which offers the ability to use young donor grafts with a greater volume of endothelial cell transfer. In addition, the pre-Descemet’s layer gives a splinting effect to the graft that allows it to be handled more easily and surgery to be completed faster and more successfully than a DMEK graft. The air pump assisted PDEK and the endoilluminator assisted PDEK techniques that help increase success of surgery will also be discussed in the video, along with further references for the viewer interested in learning more.


This video will demonstrate and explain the steps involved in performing a Pre-Descemet’s Endothelial Keratoplasty graft. From loading the graft and making a bubble, to preparing the recipient eye and closing the incision, this video will provide viewers with the ability to perform a PDEK graft.

About the Author

Soosan Jacob

Soosan Jacob, MS, FRCS, DNB, MNAMS , is Director and Chief of Dr. Agarwal’s Refractive and Cornea Foundation (DARCF) and Senior Consultant, Cataract and Glaucoma Services, Dr. Agarwal’s Group of Eye Hospitals, Chennai, India. Dr. Jacob is widely respected for her innovative techniques and management of complex surgical scenarios and has a special interest in cutting-edge cataract, cornea, glaucoma, complex anterior segment reconstruction, and refractive surgery. She has conducted courses and delivered presentations, including keynote lectures, at numerous national and international conferences. She has received a number of prestigious international awards, including from the International Society of Refractive Surgery, the American Academy of Ophthalmology (AAO), and the American Society of Cataract and Refractive Surgery, and has also won more than 50 international awards for her surgical videos. Dr. Jacob has authored more than 100 peer-reviewed publications and is the editor of 17 ophthalmology textbooks. She is Chair of the Multimedia Board AAO-ISRS, a member of the ISRS Executive Committee, and an associate editor of the Journal of Refractive Surgery.


About this video

Soosan Jacob
Online ISBN
Total duration
13 min
Springer, Cham
Copyright information
© The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer Nature Switzerland AG 2020

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Video Transcript


Hi. I’m Soosan Jacob from Dr. Agarwal’s Eye Hospital, Chennai, India. And in this video, I am going to be talking about pre-Descemet endothelial keratoplasty, or PDEK, and I’m going to be showing you the technique to perform this procedure.

Now, endothelial keratoplasty can be performed in the form of a Descemet stripping endothelial keratoplasty, or DSEK, where the graft is prepared manually and consists of a little bit of donor stroma, Descemet membrane, and endothelium.

It can also be a DSAEK, or Descemet stripping automated endothelial keratoplasty, where the same graft is prepared in an automated manner. It can be DMEK, or Descemet membrane endothelial keratoplasty, where only the Descemet membrane and endothelium are transferred. And finally, it can be a PDEK, or pre-Descemet endothelial keratoplasty where the pre-Descemet layer or the dual layer, the Descemet membrane and the endothelium are transplanted.

Now, before we understand the technique of PDEK, we must understand the types of big bubbles that can be formed when you inject air into donor cornea scleral rim. You can have a type 1 big bubble, which is essentially, as you see in this case, a bubble that starts from the center and expands outwards circumferentially.

This bubble consists of the pre-Descemet layer, the Descemet membrane, and the endothelium. On the other hand, what you sometimes get is a type 2 big bubble, where the bubble starts from the periphery and spreads over to the other side of the graft.

Now, this bubble is more flimsy in nature and consists of only the Descemet membrane and the endothelium. Sometimes you get a combination of the type 1 and type 2 bubbles, which is known as the type 3 bubble. And here, you can see it being formed. A type 1 first started in the center, and then a type 2 also got initiated from the periphery. And therefore, you have both types of big bubbles in the same donor cornea scleral rim.

Now, as you would have realized, a type 1 big bubble is basically a PDEK graft, and a type 2 big bubble is a DMEK graft. What are the advantages that a PDEK graft gives you? Basically, you can use younger grafts with higher initial endothelial cell counts, and therefore you can have better outcomes.

These grafts are also more robust and resist tearing, unlike the DMEK graft, which is very flimsy. And this allows you the advantages of performing the air pump assisted PDEK, a technique described by me, where you can literally slide the graft, center it, and get it into its correct position, remove edge folds, et cetera. And therefore, the surgery actually becomes easier to perform.

Now, the other technique that we will also talk about during the course of this series of videos is, again, one that was described by me, the endoluminator-assisted PDEK, which again helps making the surgery easier by increasing visibility, allowing you to conform orientation of the graft and so on.

For more information on PDEK, complications, complex cases, and so on, I suggest that you look at the Further Reading section at the end of this series of videos.