Abstract
Purpose: :
To investigate whether images of KP obtained with the Heidelberg Retinal Tomogram II-Rostock Corneal Module (HRT-RCM) (laser scanning confocal microscope) are superior to those obtained with the Confoscan4 (CS4) (white light slit-scanning confocal microscope).
Methods: :
Twenty-one patients (13 male, 8 female; age range: 16-85) with active uveitis and KPs were prospectively recruited from the Royal Victorian Eye and Ear Hospital. The anterior segment, in particular, KPs deposited on the corneal endothelium, of each eye was imaged during the same sitting with the slit lamp, the CS4 (Nidek Technologies, Gamagori, Japan) and the HRT-RCM (Heidelberg Engineering, Germany). All images were graded by two masked, trained graders according to strict morphological criteria.
Results: :
Eight morphologically distinct KP types were identified on the confocal microscopes. An average of 1.2 KP types were seen on slit lamp examination, in comparison to 3.4 types with the CS4 and 4.4 types with the HRT-RCM. The greater number detected by the HRT-RCM in comparison to the CS4 was statistically significant (p=0.008). Image quality overall was also superior with the HRT-RCM, as it produced 42.4% more gradable KP images than the CS4 in an average scan (p<0.001). Overall agreement between the two graders in grading KP types was found to be moderate (Κ=0.41).
Conclusions: :
Confocal microscopy elicits a greater amount of information regarding KP morphology than the standard slit lamp examination. The HRT-RCM appears superior to the CS4 in this regard, due to the greater percentage of gradable images obtained and higher number of KP types detected.
Keywords: microscopy: confocal/tunneling • imaging/image analysis: clinical • inflammation