A possible association between intraocular pressure changes and pigment epithelial detachment in central serous chorioretinopathy.

Central serous chorioretinopathy (CSC) is a frequently occurring chorioretinal disease, that is commonly associated with subretinal fluid accumulation in a generally young population. Even though choroidal abnormalities have been found to be of importance, the exact pathogenesis of CSC is still being learned. The origin of pigment epithelial detachments, seen in many CSC patients, is also unclear. Based on the follow-up of a CSC patient for more than 5 years, we hypothesize that intraocular pressure and, by extension, the pressure gradient across the Bruch's membrane, may be one factor in the pathogenesis of pigment epithelial detachments in CSC, which might very well have implications for the occurrence of and possible ways to prevent subretinal fluid in CSC.

Posture-Induced Changes in Intraocular, Orbital, Cranial, Jugular Vein, and Arterial Pressures in a Porcine Model.

Purpose: The purpose of this study was to determine posture-induced changes in arterial blood pressure (ABP), intraocular pressure (IOP), orbital pressure (Porb), intracranial pressure (ICP), and jugular vein pressure (JVP) at various tilt angles in an in vivo pig. Methods: Anesthetized and ventilated pigs (n = 8) were placed prone on a tiltable operating table. ABP, IOP, Porb, ICP, and JVP were monitored while the table was tilted at various angles between 15 degrees head up tilt (HUT) and 25 degrees head down tilt (HDT) either in stepwise changes (5 degrees per step) or continuously. The mean pressure was calculated from digitized pressure waveforms from each compartment. For stepwise changes in tilt angle the pressures were plotted as a function of tilt angle. For continuous tilt changes, the pressures were plotted as a function of time. Results: In the case of stepwise changes, ABP remained relatively stable whilst IOP, Porb, ICP, and JVP demonstrated significant differences between most angles (typically P < 0.0001). The difference was greatest for IOP (P < 0.0001) where the average IOP increased from 13.1 ± 1.23 mm Hg at 15 degrees HUT to 46.3 ± 2.03 mm Hg at 25 degrees HDT. The relationship between pressure and tilt angle was almost linear for ICP and JVP, and sigmoidal for IOP and Porb. Interestingly, the effect of changes in tilt angle occurred very rapidly, within a few seconds. Conclusions: Our results in a pig model demonstrate that changes in posture (tilt angle) induce rapid changes in IOP, Porb, ICP, and JVP, with IOP affected most severely.