Abstract
Purpose:
Corneal backscatter densitometry is a new technique provided as an add-on to the standard Pentacam software that provides an objective measurement of corneal haze by Scheimpflug assessment. The purpose of this study is to describe the corneal densitometry findings in patients with known Fuchs endothelial dystrophy and compare them with an age matched normative database.
Methods:
Seventy-seven patients with a diagnosis of Fuchs endothelial dystrophy were recruited for assessment, 68 right eyes and 63 left eyes for a total of 131 eyes. All participants were assessed using the corneal densitometry analysis on the Oculus Pentacam that takes a series of 25 images. Densitometry measurements were expressed in standardized greyscale units (GSU). Measurements were compared with previously published normative values for control densitometry values (total of 279 normal patients). The study protocol was reviewed and approved by the institutional ethics committee (ref 10/36/241). Informed consent was obtained and the research was conducted according to the tenets of the Declaration of Helsinki.
Results:
All participants were Caucasian, 40% were male and 60% were female. The means age of participants was 70.1 ± 18.8 years (range 47 - 89). Right and left eyes were highly correlated (0.68-0.90). The mean corneal densitometry over the 12mm diameter area was 29.16 ± 8.21 GSU, which was significantly higher than the controls (p <0.0001). When divided by depth, the anterior 120µm layer was 39.00 ± 11.98 GSU, the central layer was 24.98 ± 7.13 GSU and the posterior 60µm layer 23.47 ± 6.77 GSU. All three layers were significantly higher than the age matched control database (all p values <0.0001).
Conclusions:
This add-on to the standard imaging software allows rapid and objective assessment of corneal densitometry. This is the first report of this assessment method in patients with Fuchs endothelial dystrophy. When divided by layer, all layers of the cornea showed significantly higher backscatter when compared with normal controls. Despite the primary pathological process in Fuchs dystrophy occurring at the level of the corneal endothelium, the effects of the corneal guttata results in an increased degree of backscatter in all the entire corneal thickness. This new objective measurement technique may be valuable in the long-term follow up of patients and assessment post surgical intervention.
Keywords: 481 cornea: endothelium •
480 cornea: basic science •
550 imaging/image analysis: clinical