Comparative Study of the NIDEK TONOREF III and the Haag-Streit Goldmann Manual Tonometer and Comparison of Pachymetry Values for NIDEK TONOREF III With the NIDEK CEM-530

The auto ref/kerato/tono/pachymeter TONOREF III is a medical device which measures objective refractive errors, corneal curvature radius, intraocular pressure and corneal thickness of the patient's eye.

Haag-Streit Goldmann Manual Tonometer measures intraocular pressure to aid in the screening and diagnosis of glaucoma

Nidek CEM-530 is a non-contact ophthalmic microscope, optical pachymeter, and camera used for examination of the corneal endothelium and for measurement of the thickness of the cornea.