Pre-Descemet’s endothelial keratoplasty

Safe and effective means of treating various endothelial dysfunctions

Dermot McGrath

Posted: Thursday, July 6, 2017

Pre-Descemet’s endothelial keratoplasty (PDEK) offers surgeons a safe and effective means of treating various endothelial dysfunctions and compares favourably with conventional grafting techniques such as penetrating keratoplasty (PK), Descemet’s membrane endothelial keratoplasty (DMEK) and Descemet’s stripping endothelial keratoplasty (DSEK), according to Lional Raj MD.

“PDEK combined with an endoilluminator has become the endothelial keratoplasty of choice in our hospital. In our experience, pneumatic dissection of PDEK grafts is technically easier, better in endothelial preservation and can be performed in donors of any age compared to manual dissection of DMEK,” according to Dr Raj.

The pre-Descemet grafts also offer other advantages compared to other endothelial keratoplasty techniques, said Dr Raj, Medical Director of Dr Agarwal’s Eye Hospital in Tirunelveli, India.

“In our study, corneal thickness was closer to normal with PDEK than DSEK. Quality of life assessment with PDEK was also definitely better than PK in terms of pain, visual recovery, quality of vision and suture-related adverse events,” he said.

PDEK involves the transplantation of Descemet’s membrane with endothelium along with the pre-Descemet’s layer, explained Dr Raj. He noted that PDEK evolved as a keratoplasty technique thanks to the work of Prof Harminder Dua who first identified the presence of a pre-Descemet’s collagen layer which differed in several properties from the overlying posterior stroma.

Dr Raj’s prospective study included 48 patients with a variety of endothelial dysfunctions such as Fuchs’ dystrophy, bullous keratopathy, failed corneal grafts, pseudoexfoliation syndrome, post hydrops corneas and post trabeculectomy glaucoma.

Visual acuity outcomes were very good with PDEK, with 39 patients (81.25%) achieving postoperative vision of 20/60 or better. The fact that PDEK grafts can be obtained from younger donor eyes compared to DMEK is another clear advantage, said Dr Raj.

“About 50% or more of our eyes came from donors that were younger than 40 years of age. This is not possible in DMEK because the adherence of Descemet’s membrane is very high in these young individuals,” he said.

Criteria such as surgical time, endothelial preservation and corneal thickness measurements were also superior with PDEK, said Dr Raj. Patients also prefer PDEK to penetrating keratoplasty, added Dr Raj.

“Patients can feel the quality of the surgery. It is a pain-free procedure, with day care surgery and a rapid return to routine activities in seven to 10 days, as opposed to six to 12 months post PK. It is also suture-less surgery, hence there are no suture-related adverse events to worry about,” he concluded.