Abstract
Purpose :
FED affects Descemet's membrane, the endothelial mosaic, and the latter epithelium after corneal stroma. Abib presented at ARVO 2023 the Corneal Endothelial Severity Scoring System (CESSS) for FED by Specular Microscopy and possible Corneal Zones to Calculate Endothelial Cell Density to normalize and classify the endothelial mosaic areas affected by FED.
Scheimpflug imaging shows the densitometric corneal status layers:
1.Anterior peak (epithelium and Bowman membrane);
2.Cornea middle area (stroma);
3.Posterior peak (Descemet’s membrane and endothelium) in FED holders is elevated, called the Camel’s sign.
The purpose is to demonstrate the anterior and posterior densitometric amplitude of the cornea in the six degrees of the CESS for FED highlight differences between them and the control group and better describe the Camel’s sign.
Methods :
Cross-sectional study: 346 eyes, 173 patients with FED. Endothelial involvement at the corneal central area was classified using CESSS for DEF (Figure 1): Each of the six grades originated a specific group, and all were compared with the control group.
The densitometric values (DV) were calculated by the Pentacam HR (Oculus, Germany) using the Scheimpflug imaging at the corneal central area: Passive DV is default; active DV anterior is the higher value, stromal is the lower value, and posterior is the higher value, all acquired for active search at default Scheimpflug image at cornea optic area (Figure 2A).
Passive Posterior Hump Amplitude = Passive Posterior DV–Passive lower stromal DV.
Active Posterior Hump Amplitude = Active Posterior DV–Active lower stromal DV.
Mann–Whitney (Wilcoxon Rank-Sum) non-parametric version of the two-sample t-test test for independent samples, p < 0.05 is significant.
Results :
Female 72.25% and male 27.75%. Age 25-85 and 58±12 years old. Figure 2B-2E shows the descriptive statistical results and t-test for anterior and posterior hump amplitude comparing the Control Group with a CESSS 1 to CESSS 6 groups.
Conclusions :
The values demonstrated prove the existence of the Camel's Second Hump Sign and numerically follow the progression of Fuchs' Endothelial Dystrophy. They are numerically greater when densitometry is performed to search for the lowest stromal densitometric value and the highest densitometric value of the posterior cornea, both necessary to calculate the densitometric amplitude of the second Camel's hump
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.