Improved illumination for the Perkins applanation tonometer.

Aims: To improve the Perkins tonometer measurements by using an augmented, monochromatic solid-state light source of 470 nm wavelength.

Methods: This prospective study comprised 44 patients of our ophthalmic department who were split into two groups of 21 and 23 patients, and were tested by two independent ophthalmologists. Intraocular pressure (IOP) was measured in both eyes, comparing the instrument with augmented source against the standard Perkins for both observers.