Intraocular pressure response to scleral indentation

Intraocular pressure (IOP) is influenced by many factors. Our purpose was to determine the immediate response of the IOP to scleral indentation (SI). Twenty-five subjects had IOP measured using Goldmann applanation tonometry before and after SI. The total indentation time was 40 s. IOP was remeasured in a masked fashion. Average IOP for the control eyes was 15.32 mm Hg (range: 10 to 22 mm Hg) before SI and 14.80 mm Hg (range: 9 to 24 mm Hg) after SI. The average IOP for the subject eyes was 15.08 mm Hg (range: 8 to 22 mm Hg) before SI and 13.14 mm Hg (range: 6 to 22 mm Hg) after SI. These results indicate an average decrease of 1.94 mm Hg for the subject eyes vs. 0.52 mm Hg for the control eyes in response to SI. This represents a statistically significant drop in IOP among the subject eyes in response to SI (p < 0.001).