Change of Intra Ocular Pressure (IOP) and Schirmer Test (STT) in sheep naturally affected with Brucella spp

Brucellosis continues to represent a pitfall of the Mediterranean basin for the serious effects not only on animals but also in humans. As far in most states, this disease has been largely eradicated, in other countries in developing is re-emerging with an alarming incidence. This note reports the results of an ophthalmologic study carried out on a group of sheep reared in Sicily (Italy) naturally infected in order to evaluate some changes related to the infection. It was also investigated the possibility of using the tear secretion for diagnostic purposes. A group of 90 sheep, 72 seropositive and 18 seronegative (control group) was subjected to ophthalmological examination evaluating the clinical aspects of 180 eyes, eye pressure and tear secretion. At the clinical examination no subject showed lesions but it was possible to record a decrease in the Intra Ocular Pressure (IOP) and an increase of the Schirmer test (STT) in infected subjects. In seropositive animals values (mean value 11,75 mmHg) were significant compared to the control data (mean value 22.80 mmHg) and those reported in the literature (23.40 ± 1.71 mmHg.). Relatively to the tear secretion the STT has recorded mean values higher than the control group, respectively 20,11 mm/min and 15,33 mm /min; the same data are also higher than those reported in the literature (16,13mm / min) From what has been reported is clear an interesting variability both in eye pressure and in the production of tears. According to these data it can be hypothesized, as pointed out in humans, that even in sheep chronic brucellosis can cause lesions in the eye most likely related to a modification of the elements constituting the aqueous humor.