title: Association Between Platelet Function and Disc Hemorrhage in Patients With Normal-Tension Glaucoma: A Prospective Cross-Sectional Study.
abstract: OBJECTIVE
  To evaluate the association between platelet function and disc hemorrhage in patients with normal-tension glaucoma.
  
  
  METHODS
  Prospective, cross-sectional study.
  
  
  METHODS
  Study involved a total of 315 subjects, including patients with normal-tension glaucoma and disc hemorrhage (n = 120), patients with normal-tension glaucoma without disc hemorrhage (n = 75), and healthy individuals (control group, n = 120). A detailed eye examination including visual field testing, color disc photography, optical coherence tomography scanning, and measurement of collagen/epinephrine closure time using a platelet function analyzer were performed for all subjects.
  
  
  RESULTS
  The collagen/epinephrine closure time (s) as measured by the platelet function analyzer was approximately 14%-24% longer in the normal-tension glaucoma and disc hemorrhage group compared with the other groups (141.92 ± 53.44 [with normal-tension glaucoma and disc hemorrhage] vs 124.60 ± 46.72 [with normal-tension glaucoma without disc hemorrhage] vs 114.84 ± 34.84 [healthy individuals], 1-way analysis of variance test, P < .001). The activated partial thromboplastin time (s) value of the normal-tension glaucoma with disc hemorrhage group was also higher than the control group. Stepwise multiple logistic regression analysis revealed that only a longer collagen/epinephrine closure time (OR adjusted for age, sex, prothrombin time, activated partial thromboplastin time, diabetes mellitus, hypertension, hypotension, heart disease, hypothyroidism, migraine, stroke, hypercholesterolemia: 2.94; 95% CI: 1.40-6.17) was independently associated with disc hemorrhage. A similar trend was observed when platelet function was compared among the 3 groups with respect to age.
  
  
  CONCLUSIONS
  Our results suggest that platelet function is significantly associated with disc hemorrhage in patients with normal-tension glaucoma. Delayed absorption resulted from prolonged bleeding due to delayed platelet aggregation may have an effect on the detectability of disc hemorrhage in patients with normal-tension glaucoma.
authors.affiliation: Department of Ophthalmology, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, South Korea.
authors.forename: Seong Hee
authors.initials: SH
authors.lastname: Shim
authors.affiliation: Department of Ophthalmology, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, South Korea. Electronic address: joonmo1.kim@samsung.com.
authors.forename: Joon Mo
authors.initials: JM
authors.lastname: Kim
authors.affiliation: Department of Laboratory Medicine, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, South Korea.
authors.forename: Hee-Yeon
authors.initials: HY
authors.lastname: Woo
authors.affiliation: Department of Ophthalmology, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, South Korea.
authors.forename: Ko Un
authors.initials: KU
authors.lastname: Shin
authors.affiliation: Department of Ophthalmology, Chosun University School of Medicine, Gwangju, South Korea.
authors.forename: Jae Woong
authors.initials: JW
authors.lastname: Koh
authors.affiliation: Department of Ophthalmology, Seoul National University College of Medicine, Seoul, South Korea.
authors.forename: Ki Ho
authors.initials: KH
authors.lastname: Park
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001792:Blood Platelets / Q000502:physiology*; D003430:Cross-Sectional Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D057066:Low Tension Glaucoma / Q000097:blood / Q000150:complications* / Q000175:diagnosis; D008297:Male; D008875:Middle Aged; D009898:Optic Disk / Q000098:blood supply*; D011446:Prospective Studies; D012166:Retinal Hemorrhage / Q000097:blood / Q000175:diagnosis / Q000209:etiology*; D041623:Tomography, Optical Coherence; D055815:Young Adult