Posters

Pupil response to tropicamide following corneal cross-linking

Poster Details

First Author: T.Paraskevopoulos GREECE

Co Author(s):    G. Kymionis   D. Liakopoulos   A. Kouroupaki   S. Panagopoulou   M. Tsilimbaris   I. Pallikaris     

Abstract Details

Purpose:

To analyze the effect of corneal biomechanical alterations induced by performance of corneal cross-linking (CXL), on the corneal penetration of topical medication application.

Setting:

Vardinoyannion Eye Institute of Crete (VEIC), Faculty of Medicine, University of Crete, Heraklion.

Methods:

15 patients (17 eyes) were enrolled in the study. All patients had insignificant medical and ocular history, and were diagnosed with progressive keratoconus. All patients underwent CXL using the standard Dresden protocol. Measurements were performed one day pre-operatively and one month post-operatively by the same examiner under the same scotopic conditions. Central corneal thickness was measured with the use of anterior segment optic coherence tomography (AS-OCT). The pupil diameter was measured before instillation of tropicamide (Tropixal, Demo S.A, Athens) 0.5%, and every 5 minutes after instillation for a 30 minutes time duration, with the use of Colvard pupilometer.

Results:

Mean value of central corneal thickness reduced from 481μm preoperatively, to 463 μm postoperatively. The reduction was statistically significant (p = 0.005). Mean value of pupil diameter was reduced in pre-instillation measurements from 7.05mm to 6.81mm (p = 0.108). Mean value of 5 minutes and 10 minutes measurements post instillation decreased from 7.65mm and 8.16mm respectively to 7.33mm (p = 0.064) and 8.09mm (p = 0.478) respectively. The decrease was not statistically significant. At the following measurements (15, 20, 25, 30 minutes post instillation), mean value of pupil diameter did not reveal any alterations between preoperative and postoperative measurements.

Conclusions:

Pupil dilation after instillation of tropicamide 0.5% was not influenced by CXL performance, indicating that CXL did not effect the drug’s penetration, despite the biomechanical corneal changes that it induces.

Financial Disclosure:

NONE