determination of the reference value for intra ocular pressure in dogs in iran

in order to find a reference values of intra ocular pressure (lop) in the normal male and tamale dogs on the basis of sizes ages, a research project were conducted. for this purpose, during one year (1992-1993), the lop of total 360 dogs (180 males and 180 females. either large of small sizes) refered to the small animal teaching hospital of tehran university were measured by shiotz tomometer. these dogs were subdivided in to three groups of ages including less than one year old, between 1-5 years old and more than five years old in each group of the large size or the small size breeds considering the equal numbers of male or female dogs. therefore, there were 30 dogs in each of the three age groups within the large or small sizes of the males or females, totally 360 normal dogs were clinically examined. following the physical examinaties, two drops of tetracaine (0.5%) eye drops were used in the right eye of the each dog . after a few minutes the lop pressure were measured by using shiotz tomometer in the morning (a.m.) at the dark room with the presence of the owner. refering to the converting tables of human and canine tonometries, calibrated by peiffer (i 977) and pickett et al (1988) for normal canine eye, the obtained values were noted in hg milimeters follwing the accurate measurements. the results are shown in tables 1 and 2 as the average values of lop in normal male and female dogs in different size and ages subgrouped experssing in hg milimeters. analysis of variance revealed that the mean values of lop in the small size breed dogs are significantly higher than the large size breed dogs. there was no significant difference between the mean lop for male and female dogs. concerning the relationship of age and the mean values of lop in all 360 days, the statistical analysis indicated a significant difference between the lop of dogs in different ages (p