title: [Hypotony following vitreoretinal surgery].
abstract: OBJECTIVE
  To evaluate the incidence and risk factors of hypotony in patients who have undergone vitrectomy for complex retinal detachment.
  
  
  METHODS
  The medical records of 142 patients with complex retinal detachments who underwent vitrectomy were reviewed. Hypotony was defined as a persistent intraocular pressure (IOP) of 5 mmHg or less for 6 months in the follow-up.
  
  
  RESULTS
  Among this 142 patients, hypotony occurred in 16 (11.3%) in 1 year postoperatively. The rate of hypotony in the patients with traumatic retinal detachment was 18.9%, and 6.7% in the patients with rhegmatogenous retinal detachment, the difference being statistically significant (chi(2) = 4.89, P < 0.05). The rate of hypotony in aphakia was 20.9%, and 7.0% for phakia, the difference being statistically significant (chi(2) = 5.67, P < 0.05). The rate of hypotony in the patients with proliferative vitreoretinopathy (PVR)-C class was l.8%, and l5.1% in the patients with PVR-D class, the difference being statistically significant (chi(2) = 3.97, P < 0.05). The rate of post-operative hypotony in the patients with preoperative hypotony was 21.9%, and. 6.9% in the patients without preoperative hypotony, the difference being statistically significant (chi(2) = 5.16, P < 0.05).
  
  
  CONCLUSIONS
  Intraocular hypotony is a complication of vitrectomy for complex retinal detachment. The risk factors for the post-operative hypotony include trauma, aphakia, preoperative hypotony and severe PVR.
authors.affiliation: Department of Ophthalmology, Xuanwu Hospital, Capital University of Medical Sciences, Beijing 100053, China.
authors.forename: D
authors.initials: D
authors.lastname: Liu
authors.forename: L
authors.initials: L
authors.lastname: Guo
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001035:Aphakia / Q000601:surgery; D002648:Child; D002681:China / Q000453:epidemiology; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D015814:Ocular Hypotension / Q000453:epidemiology / Q000209:etiology*; D011183:Postoperative Complications / Q000453:epidemiology / Q000209:etiology; D012163:Retinal Detachment / Q000601:surgery; D012307:Risk Factors; D014821:Vitrectomy / Q000009:adverse effects*; D018630:Vitreoretinopathy, Proliferative / Q000601:surgery