Effect of Dengue Fever on Visual Functions

Abstract

Aims: To determine the frequency of defective visual functions in patients with dengue fever and to determine the association of age and duration of dengue fever with the visual functions.

Study Design: Cross-sectional study.

Duration and Settings of Study: Six months (from September  2017 to February 2018) at department of medicine, Hayatabad Medical Complex, Peshawar.

Methods: Using non-probability sampling technique, two hundred and eighteen eyes of 109 patients, admitted in hospital due to dengue fever, were included in this study. Visual functions of the patients with dengue fever were recorded. LogMAR chart for visual acuity, confrontation test for visual fields, Amsler Grid for central field, Pelli-Robson Chart for contrast sensitivity and Farnsworth D-15 Test for color vision were used. Descriptive statistics were calculated and association among the variables were analyzed through chi-square test.

Results: Out of total 109 patients, 69 (63.3%) were male. The mean age was 31.27 ± 12.18 years. Mean visual acuity of the study participants was 0.23 ± 0.25 LogMAR units. Visual field defects were found in 25 (11.47%) and Amsler Grid central field defects were detected in 36 (16.51%) eyes, while 101 (46.33%) had contrast sensitivity of 1.05-1.65 log units. Regarding color vision, 40 (18.34%) eyes had Tritan defects while 24 (11.01%) had no pattern. There was a significant association found between age and impaired visual acuity (p < 0.001).

Conclusion: Majority had impaired contrast sensitivity and almost half of the subjects had impaired visual acuity, visual fields and color vision.