Performance Evaluation of the OCUTOP Hand-held Corneal Topographer

The OCUTOP is a new hand-held camera that photographs the front of the eye to map the shape of the cornea and to assess the tear film. Before it can be used in eye care it must be compared with the instruments that clinics already use. In this study, adults attending one of two UK eye clinics for an ordinary appointment are invited to have both eyes measured once with the OCUTOP and with the clinic's usual instruments, in a random order, and to complete two short questionnaires. The visit adds about 30 minutes; nothing is put in the eye and no treatment is given. The study measures how closely the OCUTOP agrees with the reference instruments for corneal curvature, tear break-up time and tear meniscus height, how repeatable it is, how often it produces usable images, how acceptable participants and clinicians find it, and whether any adverse events occur.

Inclusion Criteria: 1. Aged 18 years or over. 2. Able to give written informed consent. 3. Attending the participating clinic for any reason. 4. Able to sit and fixate on a target for the duration of the measurements. Exclusion Criteria: 1. Unable or unwilling to give informed consent. 2. Active infection or inflammation of the eye or eyelids, or broken skin around the eye, at the study visit. 3. Any condition that prevents the eye being kept open or the head being kept steady for the measurements (for example severe blepharospasm or nystagmus). 4. Contact lens wear on the day of the visit. 5. Eye surgery within the previous three months. 6. Known sensitivity to the device's rim material or to the disinfectant wipe used between participants. 7. Taking part in another clinical investigation that could interfere with this one.