title: [The study of clinical characteristic of nonischemic central retinal vein occlusion].
abstract: OBJECTIVE; To make a comparative study of the clinical characteristics and risk factors of nonischemic central retinal vein occlusion (CRVO) between patients younger and older than the age of 40.
  
  
  METHODS
  It was a retrospective case series. Retrospective data analysis (including best corrected visual acuity, color fundus photograph and fundus fluorescein angiography, etc. ) was conducted in patients with nonischemic central retinal vein occlusion who were followed-up for 6 months or longer.
  
  
  RESULTS
  The data of 148 cases (151 eyes) were analyzed. The follow-up time was 6 months to 15 years, averaged 17 months. Among them, 39 patients (40 eyes) aged 40 years or younger, their age ranged from 15 to 40 years, averaged 27 years old. There were 20 cases of male patients (20 eyes) and accounted for 51% of total cases. The rest of the patients were above the age of 40 years old. Their age ranged from 41 to 76 years, averaged 57 years old. Male patients (53 cases, 54 eyes) accounted for 49% of total cases. In the younger patients, only 2 of them had a history of hypertension, no other systemic illness was found. In the older patients, more than 40% of them had a history of systemic illness, including hypertension and diabetes mellitus. Initial visual acuity showed no statistically significant difference between these two groups (Pearson, chi2 =0. 087, P = 0.769). There was a significant difference in final visual acuity between these two groups (Pearson, chi2 = 4.692, P = 0.047). Final visual acuity was 20/60 or better in 18 cases (45%) in the younger group, but only 25 cases (23%) in the older group. Final visual acuity was 20/200 or less in 67% of cases in the older group, while 35% in the younger group. Complications occurred more frequently in the older group. The difference of complication rate in these two groups was statistically significant (Pearson, chi = 8.763, P = 0.006). Final vision was statistically correlated with age, initial visual acuity and complications, but not with sex or systemic illness. CONCLUSIONS Systemic illness is a risk factor for the occurrence of CRVO in the older group, but not in the younger group. It does not affect the final visual acuity. Complications occurs less common in the younger group. Although final visual acuity was better in the younger group, but still 35% of them was 20/200 or less. Most of the patients in the older group have severe visual impairment. Active treatment should be given to both groups.
authors.affiliation: Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing 100730, China. luningnl@yahoo.com.cn
authors.forename: Guang-Lu
authors.initials: GL
authors.lastname: Wang
authors.forename: Feng
authors.initials: F
authors.lastname: Zhang
authors.forename: Xiao-Yan
authors.initials: XY
authors.lastname: Peng
authors.forename: Shu-Min
authors.initials: SM
authors.lastname: Meng
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012170:Retinal Vein Occlusion / Q000175:diagnosis* / Q000209:etiology; D012189:Retrospective Studies; D014792:Visual Acuity; D055815:Young Adult