Purpose:
Despite good visual acuity (VA), patients with opacities in ocular media (e.g. corneal haze, cataract) may be dissatisfied with quality of vision due to increased intraocular light scatter. The straylight meter is a new diagnostic tool which measures the objective amount of forward scatter. It holds promise for better insight in complaints of these patients. Limited clinical experience is available. We evaluated preoperative and postoperative straylight measurements in patients with Fuchs endothelial dystrophy to correlate subjective improvement postoperatively with VA and straylight. Also, the value of straylight measurements in surgical decision making is assessed.
Methods:
All patients with Fuchs endothelial dystrophy visiting the Department of Ophthalmology of the Academic Medical Center were subjected to preoperative and postoperative pachymetry, straylight measurements, evaluation of quality of vision and VA assessment on an ETDRS chart. The patients underwent posterior lamellar keratoplasty (DSEK) or penetrating keratoplasty.
Results:
25 preoperative and 15 postoperative patients were measured. Advancing Fuchs endothelial dystrophy decreased VA and increased straylight values. A twofold decrease in VA was on average accompanied by straylight increase of a factor 2.13 (figure 1). Both contribute in cumulative fashion to increase patients’ complaints. Postoperative patients showed a significant improvement in straylight values (on average by a factor of 1.58, Mann-Whitney p = 0.02), even if VA hardly changed, which lead to improved quality of vision. A threshold line was devised to assist surgical decision making, taking into account both VA and straylight. (figure 1)
Conclusions:
Patients with Fuchs endothelial dystrophy who have undergone lamellar or penetrating keratoplasty show improved quality of vision, mostly due to decreased straylight values. Straylight measurements are a promising new tool to better understand patients’ complaints. The straylight meter can contribute to surgical decision making.
Keywords: cornea: clinical science • perception • optical properties