Beyond Eye Rubbing: Mechanical Ocular Stimulation Is Highly Prevalent in Keratoconus

To investigate current and previous mechanical ocular stimulation behaviors beyond conventional eye rubbing in patients with keratoconus.

This prospective study included Japanese outpatients with a clinical diagnosis of keratoconus in at least one eye. All participants completed a structured investigator-developed questionnaire assessing current and past mechanical ocular stimulation behaviors, followed by face-to-face physician interviews. Questionnaire items included history, reasons, duration, frequency, techniques, and anatomical sites of stimulation.

A total of 304 patients were included, with 91.4% reporting mechanical ocular stimulation. These behaviors were typically long-standing (75.9% >10 years) and varied widely in motivation, frequency, methods, and anatomical sites. Ocular itching was the most common trigger (75.9%), although many behaviors were unrelated to itching. Finger pulp (56.1%) and knuckles (48.6%) were commonly used, and the medial canthus was the most commonly involved site (70.1%) (P<0.05). Pressure-related behaviors, such as eye pressing or massage during fatigue, were reported by approximately one third of patients.

The concept of mechanical ocular stimulation provides a more comprehensive framework than eye rubbing for characterizing pressure-related behaviors in patients with keratoconus. Broader assessment of current and past behaviors may improve clinical assessment and patient counseling.