Compiling information on the compositions of aqueous humor in human, rabbit, and monkey

<p>The aqueous humor, a clear liquid filling the anterior and posterior chambers of the eyeball, plays important roles in retaining the intraocular pressure and the nutrient supply to avascular tissues, such as the cornea and lens. Although information about the composition of the aqueous humor in humans and animals is useful for the development of pharmaceuticals and medical devices, it is scattered in many papers or books. In this study, we compiled the information on the composition of the aqueous humor and blood in humans, rabbits, and macaque monkeys (rhesus monkeys and cynomolgus monkeys) from the available literature. Rabbits and macaque monkeys are the species usually used for nonclinical ophthalmic studies.</p><p>We gathered information about the concentrations of approximately 60 compounds in the aqueous humor and blood, which can be classified as proteins, amino acids, low-molecular-weight organic compounds including saccharides, vitamins, and electrolytes. We found information on 26 compounds in all four animal species. It was difficult to strictly compare the data owing to differences in the times and methods of analysis. However, we identified certain tendencies between aqueous humor and blood, or among the four species. The total protein concentration was lower in the aqueous humor than in the blood, whereas the level of albumin were high in both the aqueous humor and blood. The ascorbic acid concentration was higher in the aqueous humor than in the blood in all four species. The aqueous humor electrolyte concentrations did not differ significantly among the four species or between in aqueous humor and in blood.</p><p>The information compiled in this study can be used to understand the characteristic composition of aqueous humor and the differences between species. It should be useful for pathophysiological research and the development of pharmaceuticals, medical devices, and regenerative medicine for ophthalmic fields.</p>