Aqueous humor dynamics in rats.

BACKGROUND: In order to determine normal outflow facility and aqueous humor production values in Lewis rats, we established methods of measuring aqueous humor dynamics in this animal. METHODS: Outflow facility was determined using anterior chamber infusion with constant pressure. Aqueous humor production was determined by a technique of dilution with FITC-albumin. RESULTS: The mean outflow facility was 0.044 +/- 0.01 microliter/min/mmHg. Rats weighing less than 300 g had lower values than did rats weighing more than 300 g (0.034 +/- 0.006 microliter/min/mmHg vs 0.050 +/- 0.015 microliter/min/mmHg, P = 0.009). The mean aqueous humor production was 0.350 +/- 0.110 microliter/min. The turnover rate of aqueous humor production per minute was 2.23%. CONCLUSIONS: Anterior chamber infusion with constant pressure and the FITC-albumin method allow measurement of the outflow facility and aqueous humor production in Lewis rats. These methods may be useful in assessing aqueous humor dynamics when rats are used as a glaucoma model

Translating Minimally Invasive Glaucoma Surgery Devices

Glaucoma is the leading cause of irreversible blindness with over 70 million people affected worldwide. The surgical management of glaucoma aims to lower intraocular pressure by increasing aqueous outflow facility. The latest manufacturing techniques have allowed for the development of a number of novel implantable devices to improve safety and outcomes of glaucoma surgery. These are collectively referred to as minimally invasive glaucoma surgery (MIGS) devices and are among the smallest devices implanted in the human body. This review discusses the design criterion and constraints as well as the user requirements for MIGS devices. We review how recent devices have attempted to meet these challenges and give our opinion as to the necessary characteristics for the development of future devices