Ultrastructural Investigation of the Retinal Changes in Diabetic Rat (OLETF)

PURPOSE: To compare retinal ultra-structures of diabetic rats (OLETF, Otsuka Long-Evans Tokushima Fatty) with those of agematched non-diabetic rats (LETO, Long-Evans Tokushima Otsuka) using transmission electron micrography (TEM). METHODS: The body weights and blood sugar levels of the OLETF rats and LETO rats (n=5) were measured at 10 and 50 weeks of age. Using a TEM, we compared the ultra-structural changes between the retinas of the 50-week-old OLETF and LETO rats. We analyzed the sizes of the pericytes and the thicknesses of the retinal capillary basement membranes between the two groups. Comparisons were made using a Scion Image(R). RESULTS: The mean body weight and blood sugar levels of the 50-week-old OLETF rats were significantly higher than those of the LETO rats (p(R)0.05). The thicknesses of the retinal capillary basement membranes in the outer plexiform layer and the size of pericytes were significantly increased in the OLETF rats at 50 weeks of age (p<0.05). The number of nuclei in the inner nuclear layer and the outer nuclear layer (photoreceptor cell nuclei) significantly decreased (p<0.05). However, the height of the RPE cells and basal in-foldings showed no significant differences between the OLETF and LETO rats. CONCLUSIONS: The retinal changes in the OLETF rats were observed relatively early at 50 weeks of age. These changes are similar to those seen in human diabetic retinopathy. Change in the capillaries is one feature of early retinal change. OLETF rats may be a useful animal model in NIDDM to examine diabetic retinal changes.

Analysis of Corneal Lesion using Scion Image(R)(Computer Image Analyzing Software)

PURPOSE: This study analyzed the efficacy of Scion Image(R)program, the measurement of area of cornea lesion in the process of corneal diseases. METHODS: Photographs were processed digitally from three corneal wound lesions, and the Adobe Photoshop(R) and Scion Image(R) were used to calculate the area. These measured automatically the area of the damaged corneal lesion in numerical values, allowing precise calculation of the ratio of the wounded area to the entire cornea. RESULTS: In the first case of corneal abrasion by contact lenses, we were able to measure the ratio of the lesion, improving from 45% to 9% after two days of treatment. In the second case of the typical corneal ulcer, the infected area was 23.6% of the cornea before treatment, and decreased to 14.5% after treatment. In the third case of the ring shaped corneal ulcer, we were able to measure the lesion accurately using the Scion Image(R) CONCLUSIONS: The Scion Image(R)program may be used for the measurement of corneal surface lesion. It seemed to allow objective and accurate measurement.