Effect of humidity on posterior lens opacification during fluid-air exchange

Objective: To study the relationship of humidity and the rate of lens opaci ty formation during fluid-air exchange using an animal model. Methods: Vitrectomy and fluid-air exchange was carried out using 16 eyes of 8 pigmented rabbits. One eye of each rabbit was exposed to dry air and the fellow eye received humidified air using an intraocular air humidifier. In each case, the percent humidity of the intraocular air was measured using an in-line hygrometer. Elapsed time from initial air entry to lens featheri ng was recorded for each eye, with the surgeon-observer unaware of the perc ent humidity of the air infusion. Results: In each rabbit, use of humidified air resulted in a delay in lens feathering (P < .02), with an overall increase in time to feathering of 80% for humidified air vs room air. Conclusions: Use of a humidifier during fluid-air exchange prolongs intraop erative lens clarity in the rabbit model, suggesting that humidified air sh ould prolong lens clarity during phakic fluid-air exchange in patients.