Experimental determination and allometric prediction of vitreous volume, and retina and lens weights in Göttingen minipigs.

Abstract

OBJECTIVES: To determine the vitreous volume, and retinal and lens wet weights in male and female Göttingen minipigs of different age groups. PROCEDURES: Vitreous, lens and retina were isolated from fresh minipig eyes. Vitreous volume, lens and retina weight were measured and allometric scaling was utilized to predict these parameters. RESULTS: There were no gender differences in body weights or retina and lens weights in the three age groups examined in this study. For vitreous volumes, females had a significantly larger volume (approximately 10%-12%) than males in the 4-6 and 6-8 month, but not in the 8-11-month group. The mean body weight increased from 12.2 +/- 2.6 kg (4-6 months) to 19.4 +/- 4.0 kg (8-11 months). In the same period, the mean vitreous volume increased from 2.00 +/- 0.28 to 2.67 +/- 0.31 mL, while the mean retinal and lens weights increased from 114 +/- 22 to 126 +/- 17 mg, and from 298 +/- 26 to 392 +/- 15 mg, respectively. Allometric analysis between six species for vitreous volume and four species for lens weight covering a weight range of 260-fold was not able to estimate the vitreous volume, but it did predict the lens weight in 8-11 months minipigs. CONCLUSIONS: Overall these measurements add important context to intraocular pharmacology studies, and will help in the improved design and interpretation of such experiments.