Breakdown of the Blood-Retinal Barrier after Radiofrequency-Induced Ocular Hyperthermia

Abstract

To study the possible application of hyperthermia in the treatment of proliferative vitreoretinopathy (PVR), we induced hyperthermia in 15 normal rabbit eyes by a radiofrequency capacitive heating device. The retinal surface of each eye was warmed to a presumed temperature of 41 or 43 °C for 30 min. The thermal effect on the blood-retinal barrier (BRB) was evaluated before and 2 h after the hyperthermic regimen by means of vitreous fluorophotometry. Heat treatment to 43 °C at the retinal surface for 30 min increased the fluorescein leakage compared with the 41 °C treatment. This finding suggests that retinal hyperthermia at 43 °C for 30 min may cause breakdown of the BRB.

The Effect of Ocular Warming on Ocular Circulation in Healthy Humans

“…The choroidal circulation is regulated to prevent retinal damage in response to ocular hyperthermia, which can affect the transport of substances within the eye, 21 produce coagulation of intracellular proteins, 22 cause retinal edema, 23 and break down the blood retinal barrier. 24 This function of the choroidal circulation is especially true for the macular region. 5 Parver et al 6 suggested that the CBF acts as a heat source when the temperature of the choroid is higher than thesystemictemperature.Inthepresentstudy,theCBFacted as a heat source, as the temperature of the choroid was higher than the systemic temperature as a result of ocular warming (Table 1).…”