Effects of Postural Variation on Anterior Chamber Depth in Pseudoexfoliative Eyes with Normal Intraocular Pressure

Abstract

Purpose: Pseudoexfoliation (PEX) is a condition characterized by widespread intraocular and systemic production and deposition of an abnormal fibrillar extracellular material. Zonular instability is frequently associated with PEX. Anterior chamber depth (ACD) and intraocular pressure (IOP) changes in normotensive eyes with PEX after prone position was investigated in this study.Methods: Thirty subjects with normotensive pseudoexfoliative eyes and 30 healthy control subjects were enrolled. None of the eyes had cataract or posterior synechia. Central ACD, axial length (AL), and IOP were measured 5 min after supine and prone positions by using A-scan ultrasonography and TonoPen.Results: Mean ACD decreased from 2.89 ± 0.27 mm to 2.71 ± 0.23 mm in eyes with PEX and from 2.94 ± 0.25 mm to 2.84 ± 0.30 mm in normal eyes with postural change. The ACD decreased significantly in both group of eyes in prone position (p < 0.001 in PEX group, p = 0.005 in normal group), but the decrease in ACD in eyes with PEX was significantly greater than the decrease in normal control eyes (p = 0.03). Mean IOP was 16.9 ± 2.1 mmHg after supine position and 17.1 ± 2.04 mmHg after prone position in eyes with PEX, 16.1 ± 2.7 mmHg after supine position and 16.3 ± 2.6 mmHg after prone position in normal eyes. Postural changes in IOP and AL were not statistically significant in both groups of eyes (p = 0.096 in the PEX group and p = 0.484 in the normal group for IOP; p = 0.177 in the PEX group and p = 0.276 in the normal group for AL).Conclusion: The lens is more mobile in pseudoexfoliative eyes than normal eyes after supine to prone position. Although the ACD of pseuodoexfoliative eyes decreased statistically significantly after 5 min of prone position, IOP did not change significantly.