Influence of diseased anterior segment on ocular straylight and the relation to vision related quality of life

Previous research has been performed on the factors involved in the physical
properties of straylight and clinical implications in certain ocular anterior
segment pathologies. It is known that straylight is formed by imperfect optical
media through which light is scattered onto the retina. The light distribution
on the retina is described with the point-spread-function, and the scattered
light primarily involves the area outside the 1° core, thus having little
effect on high-contrast measures of central visual acuity. The retinal light
distribution leads to the visual phenomenon of light spreading seen around
bright lights. This is called straylight.

Ocular straylight as observed by the patient can be measured using the
non-invasive Oculus C-Quant device; straylight induced by a blinking circle is
compared by the patient in blinking intensity to a light source of which the
intensity is known. As the sources are indistinguishable except for blinking
intensity, a reliable measurement can be made within about 1.5 minutes.

Anterior segment diseases that create imperfect ocular media such as cataract
and corneal scarring have been found to increase straylight independently of
affecting visual acuity. In cataract surgery straylight is found to have an
equal effect as visual acuity on quality of life on average. However, variation
was found to be large. For some patients it is difficult to predict personal
straylight levels, and not all patients with high straylight levels mention
complaints of glare. Improving knowledge about how straylight levels relate to
subjective complaints and vision related quality of life can help improve
treatment indications.

An important source of variation may be pupil diameter. It is known that media
disturbances are often distributed unevenly across the pupil opening. The
importance of this on the recorded straylight levels needs to be established.

The goal of the current study is to measure effects of straylight changes after
treatment of anterior segment disease and the relation to vision related
quality of life. A secondary goal is to further investigate the relation to
subjective glare complaints and actual straylight levels by use of a straylight
questionnaire

Primary Objective: To measure the effect of change in straylight after
treatment of ocular anterior segment disease on a vision related quality of
life score.

Secondary Objectives:
-To assess the relation of a straylight questionnaire to a vision related
quality of life questionnaire and objective straylight scores.
-To assess the pupillary diameter dependency of straylight in eyes with
anterior segment disease.

Prospective observational study, time between measurements for individual
participants depends on the waiting list for treatment and can be several
months. The full study period will be 2 years.

There is no physical risk in all examinations performed. Participants may
experience distress from straylight results that are not within expectations.
There is no direct benefit for participants and no change in clinical treatment
related to the outcomes.