Articoli Scientifici di Oftalmologia

Argomento : 2

Quantitative analysis of iris parameters in keratoconus patients using optical coherence tomography

ABSTRACT

Purpose: To investigate the relationship between quantitative iris parameters

and the presence of keratoconus.

Methods: Cross-sectional observational study that included 15 affected eyes of

15 patients with keratoconus and 26 eyes of 26 normal age- and sex-matched

controls. Iris parameters (area, thickness, and pupil diameter) of affected and

unaffected eyes were measured under standardized light and dark conditions

using anterior segment optical coherence tomography (AS-OCT). To identify optimal

iris thickness cutoff points to maximize the sensitivity and specificity when

discriminating keratoconus eyes from normal eyes, the analysis included the use

of receiver operating characteristic (ROC) curves.

Results: Iris thickness and area were lower in keratoconus eyes than in normal

eyes. The mean thickness at the pupillary margin under both light and dark conditions

was found to be the best parameter for discriminating normal patients from

keratoconus patients. Diagnostic performance was assessed by the area under the

ROC curve (AROC), which had a value of 0.8256 with 80.0% sensitivity and 84.6%

specificity, using a cutoff of 0.4125 mm. The sensitivity increased to 86.7% when

a cutoff of 0.4700 mm was used.

Conclusions: In our sample, iris thickness was lower in keratoconus eyes than

in normal eyes. These results suggest that tomographic parameters may provide

novel adjunct approaches for keratoconus screening.

Keywords: Tomography, optical coherence; Iris; Keratoconus; Cornea; Dilatation

pathologic; ROC curve