1. BIOMECHANICAL PROPERTIES OF THE CORNEA IN PSEUDO-EXFOLIATION SYNDROME Aylin Kılıç Ertan, MD Özgür Bilen, MD Kudret Eye Hospital, Ankara, Turkey There is no financial interest

2.  IOP measurement depends on:  Corneal thickness  Corneal curvature  Corneal rigidity ?

3.  Low CH is a risk factor for a tendency toward IOP underestimation  Falsely low IOP readings create the risk for misdiagnosis of potential glaucoma patients with PSX, resulting in missed or delayed glaucoma detection.

4. Corneal Hysteresis (CH) visco-elastic corneal tissue response to a dynamic deformation difference between inward and outward applanation pressures Corneal resistance factor (CRF) Linear combination of inward and outward applanation pressures, designed for maximal correlation with central corneal thickness CH and CRF : between 8 and 15 mmHg. Figure courtesy of Reichert

5. Low Hysteresis  Keratoconus  Fuchs  After corneal laser ablation  Pseudoexfoliation syndrome ??

6. Purpose  To compare corneal biomechanic properties between eyes with pseudo- exfoliation syndrome (PSX) and normal eyes

7. Method  Prospective study  76 eyes of 76 patients  Group 1: PSX (+), 41 eyes  Group 2: control, 35 eyes  CH, CRF and IOPcc were compared according to groups

8. Including criterias in Group 1: 1. eyes with manifest PSX material in precapsular layer and with or without PSX on pupil edge 2.eyes without glaucoma diagnosis

9. Gr 1Gr 2 p value PSX(+)PSX(-) IOPcc (mmHg)18,717,60.05  CH (mmHg)8,49,50.05  CRF (mmHg)8,910,0 0.05  Results T-test

11. Conclusion  There is low hysteresis in eyes with PSX without glaucoma  This may cause misdiagnosis of potential glaucoma patients  Special attention is necessary during IOP monitoring in eyes with PSX