title: Tear production and drainage after botulinum toxin A injection in patients with essential blepharospasm.
abstract: OBJECTIVE
  To evaluate the clinical manifestations of tear production, distribution and drainage in the essential blepharospasm patients, and to analyse the changes after botulinum toxin A injection in these patients.
  
  
  METHODS
  This prospective study was performed in 23 patients with essential blepharospasm treated with Botulinum neurotoxin A (BoNT-A; Dysport, Ipsen Biopharm, UK) from November 2010 to February 2011. Ocular examinations, including frequency and severity of blepharospasm, tear break up time (BUT), Schirmer's test, lower lid tear meniscus height (TMH) measured by optical coherence tomography (OCT, rtvue software version 3.5; Optovue Inc., Fremont, CA, USA), and dacryoscintigraphy using 99m technetium pertechnetate, were performed before and 2 weeks after BoNT-A injection. We asked all patients about changes in the dry eye symptom score, before and after treatment. Results were analysed with independent t-test using spss software version 12.0 for Windows XP, (SPSS Inc., Chicago, IL, USA).
  
  
  RESULTS
  Botulinum neurotoxin A treatment relieved blepharospasm in all patients. Mean injection dose was 38 ± 5.6 units. After injection, mean tear BUT was significantly increased from 4.7 ± 4.9 to 6.6 ± 1.6 seconds (p = 0.001) Lower TMH increased in all three points and most notably at the lateral point (p = 0.05). On dacryoscintigraphy, tear drainage velocity was not affected by BoNT-A treatment. But Tc-99m 50% clearance time in interpalpebral fissure significantly increased from 1564 to 2220 seconds on the time activity curve (p = 0.027). Subjective dry eye symptoms also improved in 16 patients (70%) after injection.
  
  
  CONCLUSIONS
  Tear film stability and TMH increased, but tear drainage velocity was not affected by BoNT-A treatment. Overall Tc-99m 50% clearance time in interpalpebral fissure significantly increased, and tear storage from mild lateral lower eyelid laxity increased after BoNT-A injection. Botulinum neurotoxin A injection was also effective for combined dry eye symptom in the essential blepharospasm patients.
authors: Department of Ophthalmology, CHA University, Bundang CHA Medical Center, Sungnam, Korea.
authors: Dae Il
authors: DI
authors: Park
authors: Hyun Min
authors: HM
authors: Shin
authors: Sang Yeul
authors: SY
authors: Lee
authors: Helen
authors: H
authors: Lew
mesh_terms: D001764:Blepharospasm / Q000150:complications / Q000188:drug therapy* / Q000503:physiopathology; D019274:Botulinum Toxins, Type A / Q000627:therapeutic use*; D015352:Dry Eye Syndromes / Q000150:complications / Q000188:drug therapy / Q000503:physiopathology; D005260:Female; D006801:Humans; D007273:Injections, Intramuscular; D007765:Lacrimal Apparatus / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D009301:Nasolacrimal Duct / Q000000981:diagnostic imaging; D009465:Neuromuscular Agents / Q000627:therapeutic use*; D011446:Prospective Studies; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals; D013670:Sodium Pertechnetate Tc 99m; D013666:Tears / Q000502:physiology*; D041623:Tomography, Optical Coherence
chemical_list: D009465:Neuromuscular Agents; D019275:Radiopharmaceuticals; D013670:Sodium Pertechnetate Tc 99m; D019274:Botulinum Toxins, Type A; C545476:incobotulinumtoxinA