title: Anatomical effects of clear lens extraction by phacoemulsification versus trabeculectomy on anterior chamber drainage angle in primary angle-closure glaucoma (PACG) patients.
abstract: OBJECTIVE
  To document the anatomical effects of clear lens extraction by phacoemulsification versus trabeculectomy on anterior chamber angle in patients with primary angle-closure glaucoma (PACG).
  
  
  METHODS
  Gonioscopy and ultrasound biomicroscopy (UBM) were performed pre-operatively, and at 1 year after clear lens extraction or trabeculectomy in PACG eyes.
  
  
  RESULTS
  Fifty PACG eyes of 50 patients were included. Twenty-six eyes had clear lens extraction by phacoemulsification, while 24 eyes underwent trabeculectomy. The mean extent of synechial angle closure was significantly reduced from 272.3° ± 57.3° to 253.3° ± 70.5° (p = 0.007) by phacoemulsification, but it was only reduced from 285.0° ± 64.6° to 283.1° ± 55.5° (p = 0.32) by trabeculectomy. The mean angle-opening distance at 500 microns from sclera spur (AOD500) measured by UBM was significantly increased from 220.3 ± 93.8 microns to 388.9 ± 134.1 microns (p < 0.001) by clear lens extraction, but decreased from 220.9 ± 79.8 microns to 214.5 ± 70.2 microns (p = 0.11) by trabeculectomy. The mean anterior chamber depth (ACD) measured by UBM was significantly increased from 1,983.8 ± 176.8 microns to 3335.0 ± 174.2 microns (p < 0.001) by clear lens extraction, but decreased from 2,000.2 ± 214.5 microns to 1975.8 ± 218.2 microns (p = 0.001) by trabeculectomy.
  
  
  CONCLUSIONS
  Compared to trabeculectomy, clear lens extraction resulted in a significant reduction in synechial angle closure, and an increase in anterior chamber angle width and anterior chamber depth in PACG eyes without cataract.
authors: Department of Ophthalmology & Visual Sciences, The Chinese University of Hong Kong, Hong Kong SAR, People's Republic of China.
authors: Xiaofei
authors: X
authors: Man
authors: Noel C Y
authors: NC
authors: Chan
authors: Nafees
authors: N
authors: Baig
authors: Yolanda Y Y
authors: YY
authors: Kwong
authors: Dexter Y L
authors: DY
authors: Leung
authors: Felix C H
authors: FC
authors: Li
authors: Clement C Y
authors: CC
authors: Tham
mesh_terms: D000368:Aged; D000867:Anterior Chamber / Q000473:pathology*; D001082:Aqueous Humor / Q000502:physiology; D002924:Ciliary Body / Q000473:pathology; D003315:Cornea / Q000473:pathology; D005260:Female; D015812:Glaucoma, Angle-Closure / Q000601:surgery*; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology; D007498:Iris / Q000473:pathology; D007908:Lens, Crystalline / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D018918:Phacoemulsification / Q000379:methods*; D014130:Trabeculectomy / Q000379:methods*; D058609:Visual Field Tests; D014794:Visual Fields / Q000502:physiology
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