Effect of topical prostaglandin analogues on corneal hysteresis

This is the authors' abstract. We don't add key points for this paper.

We congratulate Bolivar et al. (2015) for their study entitled ‘Effect of topical prostaglandin analogues on corneal hysteresis’. The authors investigated the effect of the prostaglandin (PG) analogues on the corneal hysteresis (CH) and corneal biomechanical behaviour. The authors found that topical PG analogues increase the CH and this increase is not related to the amount of the decrease in the intra-ocular pressure measured by Goldmann applanation tonometry. As mentioned in the study, PG analogues lead a change in central corneal thickness (CCT), increase in keratocyte density in the corneal stroma and induce extracellular matrix remodelling. How much each of this factors contributes to the PG analogue-induced CH change is unknown. In literature, there are several papers reporting CCT decrease in the human cornea after PG analogue use (Viestenz et al. 2004; Maruyama et al. 2014). Rosa et al. (2014) investigated the relationship between CH and ocular parameters, and they reported that there is a statistically significant positive correlation between CH and CCT. In other words, PG analogues seem to make a minimal decrease in CH due to slightly decrease in CCT. In the study, authors stated that CCT was measured before enrolment of the study, but there is no information for the measurement of CCT at the end of the study. We want to ask kindly to the authors if available, is there a statistically significant change in CCT and is there a significant correlation between change in CH and CCT?