Abstract
Purpose: :
SLT is known to reduce intraocular pressure effectively. Aim of the present study, however, was to evaluate the effect of SLT on corneal biomechanical properties.
Methods: :
In a prospective clinical study 39 patients with mostly advanced glaucoma underwent SLT (SoloTM SLT, ellex Inc.) for further IOP-reduction. Corneal hysteresis (CH) and the corneal resistance factor (CRF) was measured with the Ocular Response Analyzer (Reichert Inc.) prior and 4 weeks after SLT. For statistical analysis the t-test for paired samples was applied.
Results: :
74% of the patients showed an IOP-reduction after SLT from 16.8±4.1 mmHg to 13.8±3.8 mmHg (P=0.001). 31% showed even an IOP-reduction of more than 20% from 18.6±3.9 mmHg to 13.9±3.8 mmHg (P=0.001). In all patients IOP was statistically significantly reduced from 15.9±4.2 mmHg to 14.1±3.5 mmHg (P=0.001). Corneal hysteresis (CH) changed statistically significantly from 8.9±1.6 to 9.5±1.6 (P=0.019) in eyes that showed an IOP-reduction and from 8.2±1.7 mmHg to 9.7±1.7 mmHg (P=0.002) in eyes that showed a more than 20% IOP-reduction. Corneal resistance factor (CRF), an indicator of the overall resistance of the cornea changed from 9.5±1.8 mmHg to 9.1±2.1 mmHg (P=0.115) in the first group and from 9.5±2.0 mmHg to 9.3±2.3 mmHg (P=0.703) in the second group, which was not statistically significant. A correction of the CH data for the amount of IOP reduction resulted in an unchanged corneal hysteresis.
Conclusions: :
The increase in corneal hysteresis after SLT is caused by the IOP-reduction after SLT. Taking this effect in account, SLT does not change corneal biomechanical properties.
Clinical Trial: :
http://www.clinicaltrials.gov NCT01247831
Keywords: cornea: clinical science • laser • intraocular pressure