Contrast sensitivity in clinical practice.

Abstract

We collected and evaluated the results of contrast sensitivity (CS) examination by means of Vistech chart with an arranged testing distance 208 and 420 cm covering spatial frequencies 1.15-27.25 cycles/degree (c/deg). Our test was comprised of normal population and patients with chronic renal insufficiency including the group of waiting patients, dialysed patients and dialysed patients after neuroretinopathy and also patients after kidney transplantation and those with Alport's syndrome. We gave our attention to the results of visual acuity (VA) and contrast sensitivity (CS) examination in patients after surgery for detached retina, aphakic patients and patients with artephakia. We examined and evaluated CS in patients with intraocular hypertension. All patients reached the VA values 6/9-6/6. 1. The results of examination of 100 healthy persons of different age displayed significant differences in age groups covering all spatial frequencies between the groups 21-50, 51-60 and 61-80 years whereas in sets of higher age we registered differences in the region of medial spatial frequencies only. These data served us to create control groups in the individual partial groups. 2. Patients with chronic renal insufficiency have CS significantly lowered. These examinations suggest that there is a certain relation between renal and retinal functions and that the dialyzation treatment is not able as yet to compensate fully all changes evoked by renal insufficiency. A clear tendency to normalize CS after renal transplantation is suggestive of a certain reversibility of these changes. This is valid for transplant patients with a clear lens. If opacity of the posterior cortex of the lens occurs after a long-time cortisone treatment, a substantial fall in the CS curve is registered in all spatial frequencies in spite of the VA being 6/9-6/6. Patients with neuroretinopathy have CS always significantly disturbed. These changes are reversible although this reversibility is not complete. The new way of dialyzation treatment secures a relatively rapid normalisation of pathological changes in the fundus and repair of subjective functions. At the same time we came to the conclusion that the prognostic outlooks of these patients have become distinctly better as far as their subjective visual functions are concerned. 3. Patients after surgery for detached retina displayed in all cases in the operated eye highly reduced CS in median and low spatial frequencies simultaneously with a statistically significantly lower threshold visual acuity and reduced slope of the acuity function in the diseased eye.(ABSTRACT TRUNCATED AT 400 WORDS)