Skip to main content

Peripheral Epithelial Corneal Hyperfluorescence (PECH) in association with soft contact lens (CL) wear

This bachelor's thesis studies the changes in the corneal epithelium that are responsible for hyperfluorescence.

Darstellung Cell Count der HEYEX-Software in der Fokalebene von 26μm

Count of the wing cell density with HEYEX-Software (Heidelberg Engineering).

Limbal epithelial hypertrophy is described as a change in the peripheral corneal epithelial layer caused by hypoxia (a result of prolonged wearing of hydrogel contact lenses) and / or mechanical stress. Due to its characteristic peripheral location on the cornea, this phenomenon was named ‘PECH’ (Peripheral Epithelial Corneal Hyperfluorescence) for the purposes of this study.

By means of a retrospective case report study, a treatment group who wore contact lenses (CLs) on a daily basis and who also showed the characteristic symptoms of PECH (PECH yes), was statistically compared to a CL control group who had no signs of PECH (PECH no). These two groups were examined using confocal microscopy with the HRT Rostock Cornea Module (Heidelberg Engineering) at the level of the epithelial wing cell layer. Additionally, significant risk factors from a previous project (P5) were analyzed specifically regarding the potential key influence for PECH. In addition, an existing selection bias was assessed by comparing the population of the P5 project with the entire contact client base of Optik Nosch in Kirchzarten, Germany.

Statistically speaking, the wing cell layer density was significantly lower in the peripheral corneal areas with PECH. The obtained results suggest that PECH is likely to be induced by hypoxia.

Project information