Abstract
Purpose: To assess the variation in central corneal thickness (CCT) following the instillation of oxybuprocaine hydrochloride (0.4%), in normal subjects.
Methods: This was a randomized, prospective study of CCT measurements (before and after the instillation of topical anaesthesia) obtained with the Topcon SP-3000P noncontact specular microscope, in 60 eyes of thirty subjects. The subjects mean age was 20 +/- 1 years (mean +/- SD). In each subject, one eye was treated with one drop of oxybuprocaine hydrochloride (HCl) and the fellow eye with one drop of normal saline (control). The SP-3000P CCT readings were first obtained before instillation (baseline) and monitored every 30 s after instillation of each eye drop for a period of 10 min.
Results: The mean baseline CCT for oxybuprocaine was 526 +/- 23 mu m. Ten minutes after, it was 526 +/- 24 mu m. In the control, the mean CCT was 526 +/- 27 mu m, 10 min after it was 526 +/- 28 mu m. The mean variation in CCT measurement was -0.7 +/- 3.1 (5.5 to -6.8 mu m, 95% CI) for oxybuprocaine and -0.6 +/- 4.1 mu m (7.5 and -8.6 mu m, 95% CI) for the fellow eyes (P > 0.05). There was no significant variation among the 20 CCT columns for either oxybuprocaine or the control group (P > 0.05 for both).
Conclusions: One drop of topical oxybuprocaine 0.4% did not cause a significant change in CCT at up to 10 min following instillation. However, higher differences were observed at 2.30 min and 4.30 min after instillation. (c) 2012 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.