title: Long-term study of vascular perfusion effects following arteriovenous sheathotomy for branch retinal vein occlusion.
abstract: OBJECTIVE
  To evaluate the perfusion effects and long-term visual outcome of pars plana vitrectomy (PPV) combined with arteriovenous sheathotomy (AVS) with or without triamcinolone for nonischaemic branch retinal vein occlusion (NI-BRVO).
  
  
  METHODS
  Prospective, interventional case series of eight patients with NI-BRVO and haemorrhagic macular oedema. Patients underwent PPV and AVS (n = 5), or PPV, AVS and intravitreal triamcinolone (IVT, n = 3). A masked grading technique assessed fundus photographs and fluorescein angiography (FFA) following surgery. Scanning laser ophthalmoscopy/optical coherence tomography (SLO/OCT) evaluated macular oedema and outer retinal architecture. Main outcomes examined included visual acuity (VA), retinal reperfusion, collateral vessel regression, vascular dilatation, cystoid macular oedema (CMO), and ocular neovascularization.
  
  
  RESULTS
  Seven of eight patients underwent uncomplicated surgery, with increased intraretinal perfusion and reduced engorgement of distal retinal veins. The mean pre-logMAR VA was 0.8 (SD 0.17) and did not improve significantly after surgery (post-logMAR 0.6, SD 0.38; p = 0.11, paired t-test). SLO/OCT showed persistent CMO in four patients, and subfoveal thinning of the photoreceptor layer. Collateral vessels disappeared at the blockage site post-AVS in 7/8 eyes, and this was associated with improved retinal perfusion. Six of eight patients developed epiretinal membrane. No patients developed ocular neovascularization. The average follow-up was 34.5 months.
  
  
  CONCLUSIONS
  PPV with AVS is a safe procedure, and adjunctive IVT had no additional effects on vascular perfusion. Successful decompressive surgery was followed by disappearance of collateral vessels at the BRVO blockage site and was a clinical marker for intravascular reperfusion. Long-term epiretinal gliosis and subfoveal photoreceptor atrophy limited functional and visual recovery.
authors.affiliation: Manchester Royal Eye Hospital, UK. mmmk3@aol.com <mmmk3@aol.com>
authors.forename: Mahiul M K
authors.initials: MM
authors.lastname: Muqit
authors.forename: Shohista
authors.initials: S
authors.lastname: Saidkasimova
authors.forename: David
authors.initials: D
authors.lastname: Keating
authors.forename: John R
authors.initials: JR
authors.lastname: Murdoch
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D003238:Connective Tissue / Q000601:surgery*; D019299:Decompression, Surgical; D005260:Female; D005451:Fluorescein Angiography; D005500:Follow-Up Studies; D005938:Glucocorticoids / Q000008:administration & dosage; D006801:Humans; D008269:Macular Edema / Q000517:prevention & control; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012039:Regional Blood Flow; D012161:Retinal Artery; D015861:Retinal Neovascularization / Q000517:prevention & control; D012169:Retinal Vein; D012170:Retinal Vein Occlusion / Q000503:physiopathology / Q000601:surgery*; D014222:Triamcinolone Acetonide / Q000008:administration & dosage; D014792:Visual Acuity / Q000502:physiology; D014821:Vitrectomy
chemical_list: D005938:Glucocorticoids; D014222:Triamcinolone Acetonide