Straylight in anterior segment disorders of the eye

Abstract

This thesis describes new insights in the role of clinical straylight measurements in patients with ocular anterior segment disorders. Ocular straylight involves the fraction of the incoming light that is scattered by the ocular media. It does not contribute to the normal retinal image formation, but generates a rather homogeneous haze over the entire retina instead. This leads to a decrease in quality of the retinal image and complaints of hazy vision, increased glare hindrance and loss of colour and contrast perception. Ocular straylight is a comparatively new factor to be taken into consideration in clinical practice. It has been studied for years in experimental and laboratory settings and recently a survey paper has appeared. The concept of straylight fills a gap in the evaluation of patients with visual complaints, as straylight measurements are able to translate subjective complaints into quantifiable and reproducible results which provide a valuable contribution to visual tests already in use. The aims of this thesis were to study 1) the influence of the healthy and diseased anterior ocular segment on the amount of straylight and 2) which contributions straylight measurements can make in the diagnostic and therapeutic process of several corneal and lenticular disorders, in relation to the commonly accepted and universally used visual function measures such as visual acuity and slitlamp evaluation. The studies in this thesis provide additional insights in the clinical relevance of straylight measurements in a multifold of diseases and disorders which can be encountered in the practice of an ocular anterior segment surgeon