A Comparison of Visual Functions and Side-effects After DSAEK or DMEK for Fuchs' Endothelial Dystrophy

Descemet's stripping automated endothelial keratoplasty (DSAEK) and Descemet's membrane endothelial keratoplasty (DMEK) are becoming increasingly popular as treatments for Fuchs' endothelial dystrophy. However, despite several years of use the incidence of cystoid macular edema and damage related to increased intraocular pressure (IOP), and the forward scattering of light through the eye following DSAEK or DMEK have to our knowledge not been prospectively described. Therefore, this project will be a randomized controlled trial investigating these matters.

Purpose:

To investigate 3 different side-effects after DSAEK, DMEK, and cataract extraction (CE) in a randomized controlled trial with 12 months follow-up with CE as an additional control group.

1. To investigate the extend of subclinical cystoid macular edema (CME) and epiretinal membrane (ERM) after DSAEK, DMEK, and CE.
2. To investigate IOP-related changes after DSAEK, DMEK, and CE in means of pupil diameter and cpRNFLT. Further, to describe iris alterations including Urrets-Zavalia Syndrome (UZS).
3. To compare the difference in forward scatter, visual acuity (VA), and low-contrast VA after DSAEK, DMEK, and CE and relate this to the best corrected visual acuity (BCVA). Further, to investigate changes in higher-order aberrations, patient reported outcome measures (PROM), and total corneal refraction after the procedures.

Hypotheses:

1. Subclinical CME and ERM are adverse effects that occur equally often following DSAEK, DMEK, and CE.
2. Following DSAEK, DMEK, and CE, there are no differences in the amount of IOP-related changes in means of pupil diameter,cpRNFLT thinning or iris alterations.
3. Changes in OSI, HOA, PROM, VA, contrast sensitivity, and total corneal refraction occur to the same extend after DSAEK, DMEK, and CE.

Materials and Methods:

Patients referred to the Department of Ophthalmology at Aarhus University Hospital (AUH) for EK or CE will be assessed in order to identify suitable study subjects.

Only patients with primary endothelial failure (Fuchs endothelial dystrophy) and a concomitant need for CE will be considered eligible for randomization to either the DSAEK or the DMEK study groups. Patients included in the study will be randomized 1:1 to the DSAEK or DMEK study groups. Patients referred for CE will be offered to participate in the project and will be included in the CE group. Based on power calculations, it is planned to include 40 patients in each of the 3 groups.

Subject and donor characteristics will be gathered. Subjects with prior uveitis, severe vitreous opacities, diabetes, retinal vein occlusion, glaucoma, age-related macular degeneration, macular atrophy, trauma or corneal grafting will be excluded from the study. Data collection will be conducted at AUH before the interventions and in the follow-up period.

Donor tissue will be prepared in the Danish Cornea Bank, either pre-pealed for DMEK or pre-cut for DSAEK.

Measurements as described below will be conducted both prior to the surgical intervention and 3, 6, and 12 months after this.

Patients lost to follow-up during the project will only be used for analysis at the time-point they have attended. Therefore, for all time-points after the loss to follow-up these subjects will be excluded from our investigation.

In case of capsule rupture where the intraocular lens still is positioned into the lens bag during CE or if rebubbling is needed after DSAEK or DMEK, the subjects will still be eligible for further participation in the project. Adverse events such as primary graft failure or rejection is considered to be rare events for both DSAEK and DMEK and subjects with these will be excluded from our final estimates.

Eligibility Criteria:
Inclusion Criteria:

* Cataract and/or
* Fuch's endothelial dystrophy

Exclusion Criteria:

* Uveitis
* Diabetes mellitus
* Retinal vein occlusion
* Glaucoma
* Exudative age-related macular degeneration
* Advanced macular atrophy
* Ocular trauma
* Prior corneal grafting