October - LRS Institute of Tuberculosis & Respiratory Diseases

VISUAL PATTERN IN ETHAMBUTOL TREATED TUBERCULAR PATIENTS 223
symptoms were recorded earliest after 4 months
of therapy in 2 cases, but in a majority of the
cases the appearance of the symptoms was a
late feature. (Table 3). In no case symptoms
developed after It months of treatment.
TABLE 3
Time of Appearance of Symptoms
Time of appearance of symptom
4 Months
5 Months
6 Months
8 Months
11 Months
No. of patients
2
1
2
7
12
1360 eyes had normal 6/6 vision but after
18 months of therapy their number came down
to 368 The range of deterioration of vision is
shown in Table 5. The near vision acuity
also showed a similar pattern of change. In
the symptomatic group no visual disturbance
was noted prior to development of symptoms
while in asymptomatic group of patients (57
cases) the visual function disturbance was noted
for the first time only after 7 months of therapy
(in 11 cases). No visual disturbance was noticed
in any case after the treatment had continued
for 12 months (Table 6).
Visual field examination revealed that central
and paraccntral fields were normal with both
white and coloured targets, before as well as
after the therapy in all the cases included in
the present study. However, the peripheral
fields were normal for white, blue and red colors
in all the patients before as well as after the completion
of therapy but were found to have changed
in their normal relative extent for green
color (isoptre 5/330) in 71 eyes of 39 cases.
32 patients had bilateral while 7 cases had
TABLE 4
Age & Sex distribution of patients having visual function disturbance during Ethambutol therapy.
Age Group Symptomatic patients Asymptomatic patients
Males Female Total Males Females Total
Below 20 years 1 ____ 1 2 2 4
20 + to 30 yrs 10 4 14 24 10 34
30 + to 40 yrs 4 2 6 9 3 12
40 + and above 2 1 3 4 3 7
Total 17 7 24 39 18 57
Routine monthly examination revealed a
diminution of visual acuity in 81 patients
though only 24 patients had suggestive
symptoms. The age and sex distribution of the
24 symptomatic and 57 asymptomatic patients
is given in Table 4 The proportion of males
and females in both the groups is nearly the
same.
It can be seen from Table 5 that before
the start of Ethambutol therapy, 1200 of the
unilateral eye involvement. As regards the green
field changes (77) the range of diminution for
green fields was 4° to 7° in various meridians.
Fund us examination did not show any striking
change during the course of therapy except
for mild to moderate hyperemia of the optic
disc in majority of cases. In all the 81 patients,
who developed visual function disturbances
the ethambutol therapy was discontinued,
no sooner the visual function disturbance was
Ind. J. Tub., Vol. XXIX, No. 4