VARIATION OF 24-HOUR INTRAOCULAR PRESSURE IN SILICONE OIL-FILLED EYES

Purpose:To evaluate the variation of 24-hour intraocular pressure (IOP) in silicone oil (SO)-filled eyes.Methods:Prospective, nonrandomized comparative case series of 42 eyes of 21 patients, each with an SO-filled eye after vitrectomy. The fellow eyes served as controls. Each subject slept the usual 8 hours, and IOPs were measured at 4-hour intervals over 24 hours, twice before sleep (5:30 and 9:30 pm), twice during sleep (1:30 and 5:30 am), and twice after sleep (9.30 am and 1:30 pm). Intraocular pressure was measured in the sitting position using a Goldmann applanation tonometer. The SO-filled eyes and fellow eyes were compared with respect to diurnal-to-nocturnal and nocturnal-to-diurnal IOP changes.Results:At all 6 time points, SO-filled eyes had higher mean IOPs than fellow eyes (all P < 0.05). For both groups, mean nocturnal IOP was higher than mean diurnal IOP (both P < 0.001). Changes in diurnal-to-nocturnal IOP and nocturnal-to-diurnal IOP between SO-filled eyes and fellow eyes did not differ significantly (P > 0.05, respectively). The peak IOP occurred in the nocturnal period for all fellow eyes and for 94.7% of SO-filled eyes.Conclusion:The IOP of SO-filled eyes varied over a 24-hour period, peaking largely in the nocturnal period, as observed for the IOP of fellow eyes.