The short-term influence of elevated intraocular pressure on axial length

Purpose: To investigate the influence of a short period of elevated TOP (induced through the wearing of standard swimming goggles) upon axial length. Methods: Forty young adult subjects (20 myopes and 20 emmetropes, mean age 22 +/- 2 years) had their TOP and axial length measured before, during and after a 3 min period of swimming goggle wear. IOP was measured using a non-contact tonometer, and axial length with an optical biometer based upon the principle of partial coherence interferometry. Results: A 3-min period of swimming goggle wear was found to be associated with a significant increase in IOP (mean change 3.7 +/- 2.6 mmHg, p < 0.0001) and a significant axial elongation of the eye (mean change in axial length of 18 +/- 12 pm, p < 0.0001). Both TOP and axial length were found to return to baseline levels upon removal of the swimming goggles. A significant positive association was found between the changes in TOP and axial length (r(2) = 0.37, p < 0.0001). There were no significant differences between the emmetropic and myopic subjects in terms of their magnitude of change in axial length and IOP during swimming goggle wear. Conclusions: A small magnitude of elevation in TOP, induced through mechanical means and imposed for a short period of time was associated with a small but statistically significant axial elongation of the eye.