Levodopa may improve vision loss in recent-onset, nonarteritic anterior ischemic optic neuropathy.
OBJECTIVE
To study the effect of levodopa in improving visual function in patients treated within 45 days of onset of nonarteritic anterior ischemic optic neuropathy (NAION).


METHODS
Nonrandomized, retrospective, comparative trial.


METHODS
The study involved 37 patients with NAION of less than 45 days duration.


METHODS
Eighteen patients who had been treated with levodopa were assigned to the case group, and 19 untreated patients were assigned to the control group. Snellen visual acuity converted to logMAR and mean deviation on Humphrey automated perimetry (Program 24-2, Humphrey Instruments, San Leardro, CA) were evaluated at the initial and 6-month visits.


METHODS
The 18 patients in the case group were administered a capsule of 100 mg levodopa/25 mg carbidopa (Sinemet 25-100) three times daily for 3 weeks.


METHODS
The primary outcome measures were changes in visual acuity and visual field at 6 months from baseline. Improvement in visual acuity was defined as a difference of -0.3 logMAR or less between the 6-month and initial visual acuities, whereas worsened visual acuity was a difference of +0.3 logMAR or more. Each 0.3 LogMar represented a doubling of the visual angle, i.e., a change by three lines on the eye chart. Improvement in visual field was defined as a difference in mean deviation of +3.0 dB or more between the 6-month and initial visual field tests, whereas worsened visual field was a difference in mean deviation of -3.0 dB or less.


RESULTS
The proportions of patients with worsened, unchanged, and improved visual acuity at 6 months were compared for the levodopa and control groups. There was a significant difference (P = 0.012) between the groups. Examination of the proportions showed that a higher proportion of patients who received levodopa had improved visual acuity with a corresponding lower proportion having worsened visual acuity as compared with the control patients. Ten of 13 patients (76.9%) in the levodopa group with 20/40 visual acuity or worse at baseline had improved visual acuity at 6 months, and none of the 18 patients had worsened visual acuity. In contrast, 3 of 10 control patients (30%) with 20/40 visual acuity or worse at baseline had improved visual acuity at 6 months, and 3 of 19 control patients (16.3%) had worsened visual acuity. The proportions of patients with worsened, unchanged, and improved visual fields at 6 months were compared for the levodopa and control groups. There was no significant difference between the groups (P = 0.25).


CONCLUSIONS
Patients treated with levodopa within 45 days of onset of NAION were more likely to experience improvement and less likely to have worsened visual acuity than untreated patients. Levodopa appears to be beneficial in the treatment of recent-onset NAION.
Johnson
L N
LN
Neuro-Ophthalmology Unit, Mason Eye Institute, University of Missouri-Columbia, 65212, USA. JohnsonLN@health.missouri.edu
Guy
M E
ME
Krohel
G B
GB
Madsen
R W
RW
D000368:Aged; D001167:Arteritis / Q000150:complications / Q000188:drug therapy; D002230:Carbidopa / Q000627:therapeutic use*; D018491:Dopamine Agonists / Q000627:therapeutic use*; D004338:Drug Combinations; D005260:Female; D006801:Humans; D007980:Levodopa / Q000627:therapeutic use*; D008297:Male; D018917:Optic Neuropathy, Ischemic / Q000150:complications / Q000188:drug therapy*; D013997:Time Factors; D014786:Vision Disorders / Q000188:drug therapy* / Q000209:etiology; D014792:Visual Acuity / Q000187:drug effects*; D014794:Visual Fields / Q000187:drug effects
D018491:Dopamine Agonists; D004338:Drug Combinations; C009265:carbidopa, levodopa drug combination; D007980:Levodopa; D002230:Carbidopa