Moreno Montanes J, Sadaba LM, Heras H. Medición de presión intraocular con el tonómetro Proview®. Arch Soc Esp Oftalmol 2005 Feb;80(2):79-83.
Purpose: To evaluate a new ocular tonometer (Proview®) which functions by visualizing a phosphene after putting pressure on the upper eyelid. To ascertain its accuracy and reproducibility with respect to the Goldmann tonometer (GT).
Methods: A study on both eyes of 110 non-selected patients was performed. One measurement with GT and three subsequent measurements with Proview® were taken by the same investigator. The number of failed attempts to visualize the phosphene was recorded. We evaluated each eye separately to observe the possible learning effect.
Results: The intraocular pressure (IOP) mean with Proview® is 5 mm Hg higher than the GT (p<0.001). The coefficient of correlation between both instruments is low (R = 0.67; R2=0.45) in the right eye (RE). The difference between maximum and minimum values of the 3 measurements taken with the Proview® was 3.21 (SD: 1.73) mm Hg in RE. The failed attempts to see the phosphene were 5.14 (SD: 2.39) in RE and 4.93 (SD: 2.78) in left eye (p>0.05).
Conclusions: The Proview® tonometer showed low accuracy and reproducibility in comparison with the GT. This tonometer requires a long learning process before phosphene visualization. The results demonstrated that this tonometer is not clinically useful, except in patients with serious corneal diseases which make measurement with GT very difficult