The Effect Of The Fibrillar Layer Status On Corneal Optical Quality And Densitometry After Triple Dmek In Fuchs Endothelial Corneal Dystrophy

Fuchs endothelial corneal dystrophy (FECD) is characterized by progressive loss of endothelial cells. Advanced FECD is characterized by the accumulation of a collagen-rich subendothelial fibrillar layer (FL), typically located in the central to inferotemporal corneal regions.This layer can be visualized using Scheimpflug imaging and may affect the optical quality of the posterior cornea. This study aimed to evaluate the impact of the presence of an FL on corneal higher-order aberrations (HOAs) and corneal densitometry, and to analyze the preoperative and postoperative changes following triple Descemet membrane endothelial keratoplasty (DMEK).

Tertiary referral ophthalmology center

Sixty eyes from 60 patients with FECD who underwent triple DMEK were retrospectively included. Thirty FL-positive eyes were matched with 30 FL-negative eyes for patient age and sex. Corneal wavefront aberrations (Zernike polynomials, 3rd–6th order) and corneal densitometry (grayscale units) were assessed using rotating Scheimpflug imaging (Pentacam, Oculus GmbH, Wetzlar, Germany) preoperatively and at 6 months postoperatively. Mixed-effects models were used to assess the effects of time, group, and interaction. Statistical significance was set at p< 0.05.

The groups were demographically similar (age 66.0±7.4 years vs. 66.0±7.5 years, p=0.986; females comprised 66.7% of both groups). Preoperatively, FL-positive eyes showed higher posterior and total corneal higher-order aberrations (HOAs) and increased corneal densitometry, particularly in the central and anterior zones (p<0.01). Posterior coma and coma-like aberrations demonstrated significant time×group interactions (both p<0.001), with postoperative reductions in FL-positive eyes and increases in FL-negative eyes, resulting in convergence between the groups at 6 months. Corneal densitometry significantly decreased in FL-positive eyes postoperatively (p<0.001). 

The FL status is associated with distinct optical and structural characteristics in FECD eyes undergoing triple DMEK. Although FL-positive eyes exhibit higher preoperative posterior aberrations, total HOAs, and corneal densitometry, these parameters improve postoperatively, whereas FL-negative eyes tend to show postoperative increases in several aberration components. Consequently, preoperative differences between the groups diminish after surgery. These findings suggest that FL represents a marker of advanced yet potentially reversible endothelial dysfunction influencing postoperative corneal optical behavior.