[Comparative study of pneumotonometer and Goldmann tonometer for screening high intraocular pressure in primary care].

OBJECTIVE

Evaluation of reliability of measurements of IOP obtained with air-puff noncontact tonometer respect the obtained with the conventional Goldmann tonometer. As well, analysis of the possibility of a higher difference between the measurements by both methods respect the fact of being myope or hypermetrope.

DESIGN

Comparative study of two measurement methods.

SETTING

General ophthalmology clinic and primary care clinic of our sanitary area.

PATIENTS

Aleatory sample among the patients who went to the general ophthalmology clinic for any cause from the first of May to the thirtieth of June of 1996. The patients with predisposing processes for glaucoma were excluded, as well as those who suffered ocular surgery or those who took drugs which influenced the IOP.

INTERVENTIONS

The ophthalmologist made three measurements of IOP in each eye and the sight of all the patients were tested. The arithmetic average was made among every three measurements. The physician of primary care made three measurements of IOP in each eye with the air-puff noncontact tonometer, and the arithmetic average was made.

RESULTS

81 patients were included, from whom 7 presented high IOP. The sensibility of the air-puff noncontact tonometer, compared with Goldmann tonometer, was 86% (95% CI, 18.20-99.63%), and the specificity 84% (95% CI, 89.66-78.08%). The air-puff noncontact tonometer obtained measurements between 1.116 and 2.008 mmHg higher than the Goldman tonometer. This difference, worthless from the clinic point of view, didn't find a relationship with the fact of being myope or hypermetrope. It was found a positive lineal association between the measurements made by both methods, with a correlation coefficient of 0.8086 (p < 0.001, 95% CI, 0.7476-0.8560).

CONCLUSIONS

The results obtained are similar to the ones of other published series. A tendency of higher measurements with the air-puff noncontact tonometer is observed. It hasn't been observed a higher difference between both methods in myopes. The air-puff tonometer is a valid reliable technique to be used in primary care, it is easy to use, it doesn't transmit infectious illnesses, and it isn't necessary to use anaesthetic or staining eyedrops.