Author’s Response re letter by Nathan M Radcliffe

Dear Editor,

We are very interested to read Prof Radcliffe’s data showing a variable IOP rise in different subjects tested with the same goggle design. Their results, like ours,[1] suggest that individual anatomic or physiologic factors are important in determining the IOP rise. Currently, these factors are unknown with significant certainty, however some of our results identified that subjects with reduced orbital area were more prone to IOP elevation. These results were not confirmed by subsequent measurement and analysis of a separate cohort.[1] However, it is our impression that subjects with a flatter orbital profile, without a prominent orbital brow and with more soft tissue in the anterior orbit are at greater risk of IOP rise.

We also provide a service to our patients whereby we can test their IOP response to wearing goggles. We use either a standard set with holes drilled or their own and drill holes through to enable applanation tonometry whilst they wear them in the clinic. We agree fully with Prof Radcliffe that this is a useful service for glaucoma patients and suspects.

Yours Sincerely
W H Morgan

For W H Morgan, T S Cunneen, C Balaratnasingam and D-Y Yu

Reference

1. Morgan WH, Cunneen TS, Balaratnasingam C, Yu DY. Wearing swimming goggles can elevate intraocular pressure. British Journal of Ophthalmology 2008;92:1218-21.

We would like to congratulate Drs Morgan and colleagues on their recent paper “Wearing swimming goggles can elevate intraocular pressure.” We performed a similar study and presented our data at the Association for Research in Vision and Ophthalmology in 2007. Our findings demonstrated that in healthy participants, IOP measurements taken during goggle wear were significantly higher at both one and five minutes, with an average increase of 12.5% or +1.5 mmHg. A small subset of eyes (10%) in our study had an increase in IOP greater than 5 mmHg at both one and five minutes of goggle wear. We applaud the use of a predictive model in evaluating which goggles may be associated with IOP elevation. In our study, utilizing a single goggle design (Speedo), the IOP did not increase significantly in 40% of subjects but increased over 5mmHg in others. In light of this variability we have retained our prototype study goggle in order to measure the goggle-induced IOP effect in our glaucoma patients who wish to swim. Regularly testing these patients in the office allows us to better inform our patients of the potential risks of goggle wear during swimming.