Visual field and visual acuity changes in damage of chiasma opticum

Abstract

Pituitary adenoma (PA) mostly affects lateral sectors of visual field (VF), because the medial fibers of the retina intercross in the chiasma above the tumor. Enlargement of the tumour disturbes blood supply of the chiasma and demyelinisation of axons can occur. The purpose of the study is to estimate the changes of VF and visual acuity (VA) according to the diameter of PA. thirty-five persons (70 eyes) with various size of PA were tested. Perimetry and VA were estimated. Computerized program AKIENA (created in CKMU) was used for evaluation the deficit of VF. Patients were split into two groups by the diameter of PA: (i) <3 cm, (ii) >3 cm. Lateral sectors of VF were damaged for the most part in all groups ( p<0.05). VA and VF were statistically worse in the second tumor's size group ( p<0.05). There was low correlation between the size of PA and VF deficit. Also, there was low correlation between the size of PA and VA.