Levodopa as a possible treatment of visual loss in nonarteritic anterior ischemic optic neuropathy.
OBJECTIVE
To determine the clinical effectiveness and potential neuroprotection of levodopa in improving visual acuity, visual field, and retinal nerve fiber layer (RNFL) thickness in eyes affected by NAION.


METHODS
Retrospective cohort study involving 59 eyes of 59 participants with NAION who were evaluated within 15 days of NAION onset. Participants received 25 mg carbidopa/100 mg levodopa three times daily with meals for 12 weeks (levodopa group) or were untreated (control group). Best-corrected visual acuity converted to logMAR, mean deviation (MD) threshold sensitivity on automated perimetry, and mean RNFL thickness on optical coherence tomography (OCT) were assessed. The primary outcome was the categorization of eyes into improved visual acuity (by 0.3 logMAR difference), worsened visual acuity (by 0.3 logMAR difference), or no change in visual acuity. The proportions in each category were compared between the levodopa and control groups.


RESULTS
Among participants with 20/60 or worse initial visual acuity, levodopa-treated participants had significant improvement (P < 0.0001) in the mean change from initial to final logMAR visual acuity of -0.74 ± 0.56 (95 % CI, -0.98 to -0.50), while the mean change for the control group at -0.37 ± 1.09 (95 % confidence interval estimate, -1.00 to +0.26) was not significant (P = 0.23). A significant difference between groups was observed (P = 0.0086) such that 19/23 (83 %) in the levodopa group improved and none got worse, as compared with 6/14 (43 %) in the control group improving while four (29 %) worsened. The change in visual field MD and RNFL thickness on OCT showed no significant difference at P = 0.23 and P = 0.75 respectively. No levodopa-treated participant had any adverse event from the levodopa.


CONCLUSIONS
Treatment within 15 days of onset of NAION with levodopa improved central visual acuity by an average of 6 lines on Snellen acuity chart. Levodopa may promote neuroprotection of the maculopapular retinal ganglion cell fibers in NAION.
Neuro-Ophthalmology Unit, Mason Eye Institute, University of Missouri-Columbia, Columbia, MO, USA.
Deanna P
DP
Lyttle
Neuro-Ophthalmology Unit, Mason Eye Institute, University of Missouri-Columbia, Columbia, MO, USA. johnsonLN@cox.net.|Neuro-Ophthalmology Unit, Rhode Island Hospital, Department of Ophthalmology, Alpert Medical School of Brown University, 1 Hoppin Street, Suite 200, Providence, RI, 02903, USA. johnsonLN@cox.net.
Lenworth N
LN
Johnson
Neuro-Ophthalmology Unit, Department of Ophthalmology, Mount Sinai Hospital, Toronto, ON, Canada.
Edward A
EA
Margolin
Neuro-Ophthalmology Unit, Biostatistics Unit, University of Missouri-Columbia, Columbia, MO, USA.
Richard W
RW
Madsen
D000368:Aged; D000369:Aged, 80 and over; D001167:Arteritis / Q000175:diagnosis / Q000188:drug therapy; D015259:Dopamine Agents / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D007980:Levodopa / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D009412:Nerve Fibers / Q000473:pathology; D018696:Neuroprotective Agents / Q000627:therapeutic use; D018917:Optic Neuropathy, Ischemic / Q000175:diagnosis / Q000188:drug therapy*; D012165:Retinal Ganglion Cells / Q000473:pathology; D012189:Retrospective Studies; D041623:Tomography, Optical Coherence; D014792:Visual Acuity / Q000187:drug effects*; D058609:Visual Field Tests; D014794:Visual Fields / Q000187:drug effects*
D015259:Dopamine Agents; D018696:Neuroprotective Agents; D007980:Levodopa
Dopamine; Levodopa; NAION; Neuroprotection; Nonarteritic anterior ischemic optic neuropathy; Optic nerve