Porter R G, Peters J D, Bourke R D
The Royal Brisbane Hospital, Ophthalmology Department, Herston, Australia.
Ophthalmology. 2000 Apr;107(4):778-82. doi: 10.1016/s0161-6420(99)00175-x.
Condensation occurs rapidly on intraocular lenses (IOLs), particularly silicone IOLs, after vitrectomy and fluid-air exchange in the presence of a posterior capsulotomy and severely limits the surgeon's view of the retina. This study investigated the value of heating contact lens irrigation fluid to prevent condensation on IOLs.
An experimental in vitro study and a noncomparative interventional case series.
Five control eyes had temperature measurements during fluid-air exchanges. Two patients with silicone IOLs and posterior capsulotomies underwent a vitrectomy involving a fluid-air exchange with heated contact lens fluid.
An in vitro model allowed monitoring of temperature and humidity changes during condensation formation on four different IOL materials. Adjusting variables to promote evaporation rather than condensation was achieved in vitro. In vivo, intraocular temperatures were measured at various stages of five vitrectomies involving a fluid-air exchange. Finally, in two in vivo cases a blood warmer was used to heat the accessory contact lens irrigation fluid during the vitrectomy and fluid-air exchange.
Successful prevention of condensation on the silicone IOL during the fluid-air exchange.
Anterior segment temperature influences the IOL temperature, such that when it is higher than the posterior segment temperature, condensation does not form and evaporation is promoted. In vivo the temperatures in the eye are hypothermic throughout the vitrectomy. At fluid-air exchange the posterior segment heats rapidly as irrigation ceases and low specific heat gas enters. Finally, in two in vivo cases with silicone IOLs, condensation was predicted then prevented by our intervention for the duration of the fluid-air exchange.
Heating the anterior segment by conduction from warmed irrigation fluid flowing through the irrigating contact lens represents a cheap, noninvasive, and safe means to prevent condensation on IOL materials.
