In ophthalmologic examinations of nonclinical toxicity studies, descriptive recordings are required in order to objectively explain the characterization of findings to Study Directors, Project Managers, Sponsors of contracted studies, and Reviewers in governmental agencies. Appropriate descriptive recordings are useful when considering the anatomical and/or pathophysiological mechanisms of ocular findings. A descriptive recording commonly consists of terms used to record "Findings", "Tissue", "Location", "Number", "Shape", "Color", "Size", "Severities" and others. Each facility should prepare a glossary and/or dictionary for ocular terms, and should have their own standardized definitions. In the near future, submission of electronic data will be expected to be mandatory for new drug applications, and then, descriptive recordings in ophthalmologic examinations will be considered more important.
The measurement of the eye tissue is one of the important examinations in the ophthalmic field, and the measurement of axial length is also included there. Normal value of axial length of dogs has been reported to be about 20∼22 mm, but most data is about medium-sized breed. We could not find reports of axial length in small breed. The purpose of this study was to establish a reference value of axial length of the small breed. When we targeted Chihuahua by B-mode, we found that mean value of ocular axial length was 18.1mm.And it was the shortest value reported in that of the dogs in the past, although the difference among 3.3 mm was accepted at the maximum. Moreover, when statistical examination was performed about the relation of weight and axial length value, only weak positive correlation was found by both;that is high correlativity was not found statistically. This study is the first report of measurement on the value of eye tissue and axial length of normal Chihuahua by B-mode.