The effect of an artificially-elevated intraocular pressure on corneal thickness in Chinese eye

We measured the central corneal thickness and the applanation intraocular pressure (IOP) on 45 Hong Kong Chinese. There was no obvious relationship between these two parameters, as different from other literatures. It could be due to either a limited number of subjects with a high IOP level (only six subjects with IOP ≤ 22 mmHg), or Chinese has a thicker central cornea in general. The mean central cornea of our subjects was thicker (566 ± 35 μm) than some previous findings. Thirty subjects had their intraocular pressure further increased by adopting a 40°head-down posture. Their IOP and topographic corneal thickness were measured again. There was no significant change in the central corneal thickness even though the IOP was elevated by 11.7 mmHg. However the nasal cornea demonstrated a thinning effect (by some 18 μm) during the IOP elevation but it returned to the pre-inverted level after returning to a sitting posture for 5 min. Further investigation with more corneal regions being measured would be valuable to evaluate the in vivo effect of IOP elevation from glaucoma attack on corneal thickness.