Results - Details
Search command : Author="Τσιλιμπάρης"
And Author="Μιλτιάδης"
Current Record: 15 of 105
|
Identifier |
000421392 |
Title |
Αξιολόγηση πρώιμης και ανώτερης οπτικής συμπεριφοράς του φυσιολογικού οφθαλμού μονόφθαλμων ασθενών |
Alternative Title |
Evaluation of visual performance in patients with severe visual impairment in one eye |
Author
|
Γιαννακοπούλου, Τρισεύγενη
|
Thesis advisor
|
Τσιλιμπάρης, Μιλτιάδης
|
Reviewer
|
Παλλήκαρης, Ιωάννης
Σιγανός, Χαράλαμπος
Δετοράκης, Ευστάθιος
Βελεγράκης, Γεώργιος
Σπανάκη, Κλεάνθη
Σίμος, Παναγιώτης
|
Abstract |
Purpose: It is widely accepted that monocular deprivation results in improved visual
performance in the non-pathological eye. The current study investigates first the effect of
deprivation due to severe impairment in one eye during late childhood or adulthood, on the
spatial performance of the fellow “good” eye, and secondly, whether one-eyed patients
show any advantages over the binocular vision of normally-sighted individuals under
conditions of defocus blur.
Methods: Patients with severe visual impairment in one eye (visual acuity equal or worse
than count fingers at 1m), for a period longer than 2 years, participated in the study. Only
patients with an age less than 50 years and monocular deprivation onset greater than 9
years were included. In Part A, best-corrected contrast sensitivity was evaluated using
reversing vertical sinusoidal gratings at 7 spatial frequencies. In Part B, the effect of defocus,
induced by positive lenses up to 2.50D, on the pattern reversal Visual Evoked Potential
(VEP) and on visual acuity (VA) was measured. Performance of the control group was tested
both monocularly (dominant eye) and binocularly.
Results: In Part A, binocular viewing of normally-sighted subjects, improved contrast
sensitivity by 70% compared to monocular recordings. Average contrast sensitivity in
subjects with impaired vision in one eye was found to be higher by 83% compared with the
dominant eye of the control group. The increase in sensitivity was independent of spatial
frequency. In Part B, VA was always better with binocular than with monocular vision in the
control group, with the difference being greater for higher levels of retinal blur. In subjects
with one eye average VA was less affected by defocus, similar to the binocular vision of
normal controls. The effect of defocus on VEP P100 latency and amplitude in one-eyed
patients was similar to the one exhibited in normal under binocular viewing conditions.
However statistical significant difference between monocular performance of the two
groups was only found for P100 amplitude; the difference in P100 latency did not reach
statistical significance.
Conclusions: The findings are consistent with growing evidence supporting functional vision
changes in patients with severe impairment in one eye, as a result of altered experience in
the adult vision system.
|
Language |
Greek |
Subject |
Contrast sensitivity |
|
Monocular deprivation |
|
Visual evoked potential |
|
Αποστέρηση |
|
Εναπομείναντας οφθαλμός |
|
Ευαισθησία φωτεινής αντίθεσης |
|
Θόλωση |
|
Οπτικά προκλητά δυναμικά |
Issue date |
2019-03-27 |
Collection
|
School/Department--School of Medicine--Department of Medicine--Doctoral theses
|
|
Type of Work--Doctoral theses
|
Permanent Link |
https://elocus.lib.uoc.gr//dlib/7/5/d/metadata-dlib-1554464035-570606-7062.tkl
|
Views |
425 |