Glaucoma Research Today is a free monthly online journal that collates and summarizes the latest research about Glaucoma, including details on cataracts, surgery, treatment, blindness.

Identifying preperimetric functional loss in glaucoma: a blue-on-yellow multifocal visual evoked potentials study.

Arvind H, Graham S, Leaney J, Grigg J, Goldberg I, Billson F, Klistorner A

Save Sight Institute, University of Sydney, Sydney, Australia. hema@eye.usyd.edu.au

PURPOSE: To determine the ability of blue-on-yellow multifocal visual evoked potentials (BonY mfVEP) to identify functional loss in preperimetric glaucoma. DESIGN: Prospective case series. PARTICIPANTS: Thirty patients with glaucomatous optic discs and normal standard visual fields. METHODS: All patients underwent BonY mfVEP, dilated optic disc stereophotography, and optical coherence tomography (Fast RNFL protocol). Optic disc photographs were assessed by 2 independent examiners in a masked fashion. MAIN OUTCOME MEASURES: The mfVEP amplitude asymmetry and latency values were analyzed and compared topographically with findings of disc assessment. Average retinal nerve fiber layer (RNFL) thickness, RNFL asymmetry, and sectors with RNFL thinning were compared between patients with and without mfVEP defects. RESULTS: Fourteen (46.7%) patients demonstrated significant abnormality on amplitude asymmetry deviation plots of BonY mfVEP. In all 14 cases, the defect was monocular and corresponded to the eye with the worse disc. In 13 of 14 patients, the defect also corresponded to the location of the worst affected rim. Average RNFL thickness of eyes with mfVEP defects was 81.2+/-9.9 microm, significantly lower than that of patients without defects (90+/-10.5 microm; P = 0.035). Mean asymmetry of RNFL (better minus worse eye) also was significantly higher for patients with mfVEP defects compared with those without such defects (9.0+/-6.4 microm vs. 3.0+/-7 microm; P = 0.03). Average latency of both eyes of glaucomatous patients was delayed compared with that of controls, with no difference in latency between worse and better eyes of glaucoma patients. There was no association of latency delay with either the location of disc changes or mfVEP amplitude defects. CONCLUSIONS: Amplitude asymmetry of the BonY mfVEP seems to be a promising tool to identify functional loss in preperimetric glaucoma. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found after the references.

Published 2 June 2009 in Ophthalmology, 116(6): 1134-41.
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Articles on Glaucoma published 2 June 2009:

Risk factors for poor adherence to eyedrops in electronically monitored patients with glaucoma.   Ophthalmology, 116(6): 1097-105.

PURPOSE: To identify risk factors for poor adherence to topical once daily therapy for glaucoma. DESIGN: Prospective, observational cohort study. PARTICIPANTS: A total of 196 patients with glaucoma who were being treated with a prostaglandin analog in 1 or more eyes at the Scheie or Wilmer Eye Institutes between August 2006 and June 2007. METHODS: Demographics, ocular history, and responses to interview questions about glaucoma knowledge, health beliefs, and drop-taking behaviors were obtained ... [Abstract] [Full-text]

Sector-based analysis with the Heidelberg Retinal Tomograph 3 across disc sizes and glaucoma stages: a multicenter study.   Ophthalmology, 116(6): 1106-11.e1-3.

PURPOSE: To investigate the ability of sectorial analysis using the Heidelberg Retinal Tomograph 3 (HRT3) to discriminate between healthy and glaucomatous eyes and to determine whether this is affected by disc size and glaucoma severity. DESIGN: Multicenter, cross-sectional evaluation of diagnostic tests. PARTICIPANTS: Two hundred thirty-three eyes from 137 normal subjects and 96 glaucoma patients classified by the presence of a repeatable visual field defect. TESTING: Participants underwent ... [Abstract] [Full-text]

The Relationship between intraocular pressure and progressive retinal nerve fiber layer loss in glaucoma.   Ophthalmology, 116(6): 1125-33.e1-3.

PURPOSE: To evaluate the relationship between intraocular pressure (IOP) and progressive retinal nerve fiber layer (RNFL) loss, as measured by scanning laser polarimetry with enhanced corneal compensation (GDx ECC), in a cohort of glaucoma patients and individuals suspected of having the disease followed over time. DESIGN: Observational cohort study. PARTICIPANTS: The study included 344 eyes of 204 patients recruited from the Diagnostic Innovations in Glaucoma Study (DIGS). There were 98 eyes ... [Abstract] [Full-text]

Articles on Glaucoma published 27 May 2009:

A randomised crossover study comparing bimatoprost and latanoprost in subjects with primary angle closure glaucoma.   Br J Ophthalmol, 93(6): 782-6.

BACKGROUND/AIMS: To compare the intraocular pressure (IOP) lowering efficacy and side effects of latanoprost 0.005% and bimatoprost 0.03% in subjects with chronic primary angle closure glaucoma (PACG). METHODS: This was an observer-masked randomised crossover study of 60 PACG subjects who received either latanoprost or bimatoprost for 6 weeks, after which they were crossed over to the other medication for another 6 weeks. The IOP-reducing effect of the medications was assessed by the reduction ... [Abstract] [Full-text]

Agreement between spectral-domain and time-domain OCT for measuring RNFL thickness.   Br J Ophthalmol, 93(6): 775-81.

BACKGROUND/AIMS: To evaluate spectral-domain (SD) optical coherence tomography (OCT) reproducibility and assess the agreement between SD-OCT and Time-Domain (TD) OCT retinal nerve fibre layer (RNFL) measurements. METHODS: Three Cirrus-SD-OCT scans and one Stratus-TD-OCT scan were obtained from Diagnostic Innovations in Glaucoma Study (DIGS) healthy participants and glaucoma patients on the same day. Repeatability was evaluated using Sw (within-subject standard deviation), CV (coefficient of ... [Abstract] [Full-text]

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AIM: To compare the 2-year survival rates of polypropylene and silicone Ahmed glaucoma valves (AGVs) implanted during the first 2 years of life. METHODS: Retrospective analysis of polypropylene and silicone AGV implantation during the first 2 years of life in children with 2 years' postoperative follow-up. Patients with prior aqueous drainage device implantation were excluded. RESULTS: Forty-two eyes of 36 children were reviewed. Thirty-one eyes received a polypropylene AGV (six S1, 25 S2), and ... [Abstract] [Full-text]

Exploring functional candidate genes for genetic association in german patients with pseudoexfoliation syndrome and pseudoexfoliation glaucoma.   Invest Ophthalmol Vis Sci, 50(6): 2796-801.

PURPOSE: Pseudoexfoliation (PEX) syndrome is a generalized elastic microfibrillopathy characterized by fibrillar deposits in intra- and extraocular tissues. Genetic and nongenetic factors are known to be involved in its etiopathogenesis. This study was focused on six functional candidate genes involved in PEX material deposition and the analysis of their potential association with PEX syndrome and PEX glaucoma (PEXG). METHODS: Fifty single-nucleotide polymorphisms (SNPs) capturing >95% of ... [Abstract] [Full-text]

Complications and 2-year valve survival following Ahmed valve implantation during the first 2 years of life.   Br J Ophthalmol, 93(6): 795-8.

AIM: To report complications and 2-year valve survival following Ahmed valve implantation during the first 2 years of life. METHODS: Retrospective institutional case series. RESULTS: Forty-two eyes of 36 patients with Ahmed valve implantation (without prior drainage device surgery) during the first 2 years of life and 2 years' postsurgical follow-up were identified. Most eyes had primary congenital glaucoma (28/42, 66.7%), aphakic glaucoma (5/42, 11.9%) or Peters anomaly (5/42, 11.9%). All but ... [Abstract] [Full-text]

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