title: Cross-sectional study of the retinal nerve fiber layer thickness at 7 years after an acute episode of unilateral primary acute angle closure.
abstract: The purpose of this article is to investigate the long-term retinal nerve fiber layer (RNFL) status and determinants of RNFL thinning after an episode of unilateral primary acute angle closure (AAC). This cross-sectional study analyzed the medical records of consecutive patients with a single episode of unilateral AAC from 1999 to 2009 in Hong Kong. The peripapillary RNFL thickness was correlated with age, gender, presenting intraocular pressure (IOP), time to laser iridotomy, time to cataract extraction, follow-up duration, as well as the last IOP, vertical cup-to-disc ratio (CDR), and vision. The fellow uninvolved eye was used as a proxy comparison of RNFL loss in the attack eye. In 40 eligible patients, the mean age was 68.3 ± 8.7 years with a male-to-female ratio of 1:7. The mean presenting IOP was 49.2 ± 14.0 mm Hg and the time from presentation to laser iridotomy was 6.7 ± 6.9 days. Forty percent of subjects received a cataract extraction at 3.2 ± 2.9 years after the attack. The last IOP, CDR, and LogMAR vision were 16.0 ± 3.8 mm Hg, 0.6 ± 0.2, and 0.6 ± 0.6 LogMAR units, respectively, at 7.9 ± 2.4 years. The RNFL thickness in the attack eye (69.2 ± 19.1 μm) was 25.2 ± 17.9% thinner than the fellow eye (93.0 ± 17.8 μm) at 7.5 ± 2.9 years post-AAC. Using univariate analysis, the last vertical CDR (odds ratio [OR] = 17.2, P = 0.049) and LogMAR visual acuity (VA) (OR = 6.6, P = 0.03) were the only significant predictors for RNFL thinning whereas none of the other covariates showed significant associations (P > 0.1). At 7.5 years following unilateral AAC, the RNFL thickness was 25% thinner than the fellow eye. CDR enlargement and poor VA were the only significant predictors for RNFL loss.
authors.affiliation: From the Department of Ophthalmology (JWYL, TTYW, GSKY, DWFY), The Department of Ophthalmology, Caritas Medical Centre (JW); Department of Applied Mathematics (SY), The Hong Kong Polytechnic University; Department of Ophthalmology and Visual Sciences (RLMW), Hong Kong Eye Hospital; and Department of Ophthalmology (IYHW), The University of Hong Kong, Hong Kong SAR, People's Republic of China.
authors.forename: Jacky W Y
authors.initials: JWY
authors.lastname: Lee
authors.forename: Tiffany T Y
authors.initials: TTY
authors.lastname: Woo
authors.forename: Gordon S K
authors.initials: GSK
authors.lastname: Yau
authors.forename: Stan
authors.initials: S
authors.lastname: Yip
authors.forename: Doris W F
authors.initials: DWF
authors.lastname: Yick
authors.forename: Jasper
authors.initials: J
authors.lastname: Wong
authors.forename: Raymond L M
authors.initials: RLM
authors.lastname: Wong
authors.forename: Ian Y H
authors.initials: IYH
authors.lastname: Wong
mesh_terms: D000208:Acute Disease; D000368:Aged; D057186:Comparative Effectiveness Research; D003430:Cross-Sectional Studies; D003937:Diagnosis, Differential; D005260:Female; D015812:Glaucoma, Angle-Closure / Q000150:complications / Q000503:physiopathology; D006723:Hong Kong; D006801:Humans; D008297:Male; D008875:Middle Aged; D009898:Optic Disk / Q000473:pathology*; D009901:Optic Nerve Diseases / Q000175:diagnosis / Q000209:etiology; D012307:Risk Factors; D013995:Time; D041623:Tomography, Optical Coherence / Q000379:methods*; D014792:Visual Acuity; D058609:Visual Field Tests / Q000379:methods