Three patients reported acute, painless, bilateral visual loss. The clinical features, biological parameters, clinical treatments and methanol concentration in work environment and commercial alcohol are presented in Table 1.
Table 1 Clinical characteristics, biological parameters, clinical treatments of patients.
Variables
|
Case 1
|
Case 2
|
Case 3
|
Clinical characteristics
|
Age in years
|
48
|
56
|
38
|
Gender
|
male
|
male
|
male
|
Granulation working life spans
|
8 years
|
3 months
|
5 years
|
Vital signs
|
Body temperature
|
37.7°C
|
36.7°C
|
36.7°C
|
Respiratory rate
|
25/min
|
22/min
|
22/min
|
Heart rate
|
100/min
|
74/min
|
82/min
|
Systolic/diastolic blood pressure
|
139/97mmHg
|
120/70mmHg
|
145/100mmHg
|
Biological parameters
|
pH
|
7.09
|
7.28
|
7.26
|
PaO2
|
34 mmHg
|
126.5 mmHg
|
118 mmHg
|
PaCO2
|
39 mmHg
|
23.3 mmHg
|
15.6 mmHg
|
Actual bicarbonate
|
11.8 mmol/L
|
16.9 mmol/L
|
No test
|
Standard bicarbonate
|
9.3 mmol/L
|
20.1 mmol/L
|
No test
|
Uric acid
|
690 μmol/L
|
568 μmol/L
|
528.1 μmol/L
|
White blood cell count
|
10.18×109
|
11.58×109
|
17.99×109
|
Percentage of neutrophils
|
96.1%
|
72.61%
|
91.1%
|
Clinical treatments
|
Hemodialysis
|
Yes
|
Yes
|
No
|
Acidosis correction
|
Yes
|
Yes
|
Yes
|
Glucocorticoids
|
Yes
|
Yes
|
Yes
|
Water and electrolyte balance
|
Yes
|
Yes
|
Yes
|
Nerve nutrition
|
Yes
|
Yes
|
Yes
|
Vitamin B supplement
|
Yes
|
Yes
|
Yes
|
Hospital stays
|
19 days
|
31 days
|
10 days
|
Clinical outcomes
|
Left 1.0
Right 0.8
|
Left 0.6
Right 0.6
|
Vision loss
|
Methanol concentration
|
In work environment(mg/m3)
|
1355.8±803.0
|
3021.8±896.6
|
1097.2±114.5
|
In commercial alcohol(g/100mL)
|
79.9
|
79.3
|
96.3
|
Case 1
A 48-y-old male was admitted to hospital with blurred vision, chest tightness, vomiting, shortness of breath. He had engaged in fireworks granulation work and sprayed adhesive agent into granulating pellet machine by air pump for 8 years. On day 2, his vision deteriorated continuously and could not identify the content of the phone screen. The fundus examination revealed abnormal macular reflex. He was diagnosed with acute methanol poisoning, toxic optic neuropathy and type I respiratory failure. Naked vision of both eyes was 0.06. Fundus examination showed indistinct macular center concave reflection. After the treatment of hemodialysis, short-term glucocorticoids, and other symptomatic treatments, such as acidosis correction, oxygen inhalation, nerve nutrition, vitamin B supplement liver protection, water and electrolyte balance maintenance, his visual acuity had returned to normal (1.0 in the left eye and 0.8 in the right eye) on day 19.
Case 2
A 56-year-old male was admitted to hospital with progressive blurred vision, narrowed visual field, chest tightness and dizziness. Naked eye vision examination: no light perception in the right eye, and visible only at 30 cm in the left eye. He was diagnosed with acute methanol poisoning, and treated with timely hemodialysis and short-term glucocorticoids. Other treatments according to syndromes, such as acidosis correction, oxygen inhalation, nerve nutrition, vitamin B supplement liver protection, water and electrolyte balance maintenance. His bilateral visual acuity had returned to 0.6 on day 31.
Case 3
A 38 -year-old male was found with severe chest pain,chest tightness, shortness of breath, and progressive blurred vision. He had engaged in fireworks granulation work for 5 years discontinuously. He couldn't see anything in 10 hours.
Fundus examination showed light reflex disappearance, mydriasis (6 mm), double papillary edema, enlargement of the optic disc cup (C/D 0.75), slightly pale optic disc, fuzzy optic disc boundaries and less thickness of macular fovea. He was treated with glucocorticoids and other symptomatic treatments other than hemodialysis. His eyesight was not improved on day 10 and finally diagnosed with bilateral nerve atrophy and blindness (no light perception) in two months.