Lens as the Chief Source of Fructose in Rabbit Aqueous Humor

Three months after the left eyes of seven rabbits had been rendered aphakic, samples of aqueous humor from the anterior chamber of both eyes and blood samples from the ear vein were removed and analysed for fructose, glucose and lactic acid. The average fructose level was 5.4 mg/l00 ml aqueous humor in the normal eyes as compared to a level of 1.4 mg/l00 ml in the aphakic eyes. The blood fructose level was 1.7 mg/l00 ml plasma, which is not significantly different from the level found in aphakic aqueous humor. The glucose levels in the aqueous humor were not affected by lens removal. In aphakic eyes, the aqueous humor lactic acid level was 60% of the normal. From these data, it is clear that the lens is the only ocular tissue that supplies fructose to the aqueous humor. It has also been confirmed that the lens supplies to the aqueous humor only a part of the lactic acid not derived from the blood.