PURPOSE. The Collaborative Longitudinal Evaluation of Keratoconus (CLEK) Study uses 35 mm slides to document fluorescein fitting patterns of rigid contact lenses in keratoconus. This initial pilot study compares digital imaging to slide photography in the evaluation of these fluorescein patterns.
METHOD. Fluorescein patterns of habitually worn contact lenses are photographed by a clinician with 35 mm slide film using the standard CLEK protocol. The lenses are then digitally imaged by a second clinician using the Haag-Streit EyeCap System. The digital images and 35 mm slides are read by a masked observer. Each central, apical fluorescein pattern observation results in a grade of definite touch, touch, clearance, or definite clearance of the cornea. These photographic assessments are compared with the clinician’s examination assessment.
RESULTS. In the first 12 eyes observed, when outcomes are dichotomized to touch or clearance outcomes, there was agreement for nine eyes. There was disagreement for three eyes. In one of these eyes, the clinician graded the fit as clearance, the slide was graded as touch, and the digital image was graded as touch. In another eye, the clinician graded the fit as clearance, the slide was graded as clearance, and the digital image was graded as touch. In a third eye, the clinician graded the fit as touch, the slide was graded as clearance, and the digital image was graded as touch.
CONCLUSIONS. Digital imaging is a promising alternative to 35 mm photography for the evaluation of rigid contact lens fit. These pilot results indicate that the digital system has good potential for agreement between the clinician and the image reader. In addition, the clinician gets instant feedback on the digital images and can therefore ensure that the lenses are in proper position and that the image is focused, properly illuminated, and represents what is seen on the eye.