Purpose:
To quantify corneal backscattering by densitometry analysis after pre-Descemet endothelial keratoplasty (PDEK).
Design:
This is a prospective observational case series.
Methods:
Setting: Tertiary care hospital. Participants: Postoperative PDEK eyes with best-corrected visual acuity (BCVA) ≥20/40 without comorbidity. Observation procedure: Slit-lamp examination, Scheimpflug imaging (Pentacam; Oculus, Wetzlar, Germany), endothelial cell density (cells/mm2), and central corneal thickness (Visante; Carl Zeiss AG, Oberkochen, Germany) were performed. Corneal densitometry values for the entire depth of the cornea were compared between post-PDEK eyes and fellow eyes (non-PDEK). Main outcome measures: Mean densitometry (grayscale units, GSUs) of the anterior, posterior, central, total depth and concentric zones (0–2, 2–6, 6–10, and 10–12 mm) of the cornea.
Results:
Overall, 35 eyes (21 PDEK eyes and 14 control eyes) were evaluated. The mean total densitometry values in the anterior, central, and posterior corneas were 40.7 ± 7.6 GSU, 25.3 ± 4.8 GSU, and 20.9 ± 3.4 GSU, respectively. On inter-zone comparison between central and peripheral cornea, there was a statistically significant difference (P < 0.05) between 0 to 2 mm and 6 to 12 mm zones. There was no correlation between endothelial cell density and central corneal thickness with densitometry. However, there was a significant correlation of BCVA with corneal densitometry in 0 to 2 mm (r = 0.519, P = 0.016) and 6 to 2 mm (r = 0.556, P = 0.009) zones. In eyes with BCVA 20/20, there was no significant difference between PDEK and control eyes in the total corneal densitometry in the entire depth of the cornea (P = 0.662).
Conclusions:
Clinically clear corneas with visual acuity 20/20 showed no difference in the total corneal densitometry as compared to their fellow eye. Corneal backscatter was higher in the anterior cornea and in the central 0 to 6 mm zone.
